ATTENTION! The following header is not fully valid yet!
From: dl4mhk@lrz.uni-muenchen.de (Bernhard Hailer)
Newsgroups: de.alt.comm.isdn4linux,de.answers,news.answers
Subject: ISDN4linux-FAQ
Followup-To: de.alt.comm.isdn4linux
Summary: This posting describes what every reader of de.alt.comm.isdn4linux
         ought to know about ISDN under Linux using isdn4linux.  
         This is an English translation of the original document, which is
         in German, like the Newsgroup.
Archive-name: eng-i4l-faq
Posting-frequency: monthly
Last-modified: 18-Mar-97
URL: http://www.lrz-muenchen.de/~ui161ab/www/isdn/

FAQ for isdn4linux - Version 1.3.3
(translation 3-Oct-97)

1 General information about isdn4linux

What is isdn4linux?
What can isdn4linux do?
What can't isdn4linux do (yet)?
Can I use isdn4linux in North America?
What do I need for isdn4linux?
How can I get isdn4linux?
What documents should I read first?
What helpful links are there about isdn4linux?
Is there a mailing list for isdn4linux?
How can I have myself removed from the mailing list?
Is the mailing list mirrored to a newsgroup?
Is there an archive of the isdn4linux mailing list?
In which countries does isdn4linux work?
Is isdn4linux approved for use by the telecommunications authorities?
What is the most recent version?
What hardware is NOT supported?
Does isdn4linux support external terminal adapters?
Which internal cards are supported?
What is the new HiSax driver all about?
What about the active AVM B1?
Now that my AVM produces so many interrupts with the HiSax driver, which is the best passive card to use with HiSax?
Does isdn4linux support external ISDN adapters?
Which ISDN modes are supported?
Does isdn4linux support channel bundling?
What is the difference between an active and a passive ISDN card?
Are there sites that offer guest access where I can test my isdn4linux setup?
Can I combine isdn4linux with diald?
Can I use isdn4linux as an answering machine?
Can I fax with isdn4linux?
Is videotex/Btx/Datex-J possible with isdn4linux?
Can I connect to Compuserve with isdn4linux?
Which ISDN features can not be offered by isdn4linux?
I'd like to write a new hardware driver. Where can I find a description of the interfaces to the link level module?
How can I access the source from the current development/what is the CVS tree all about?
Can I use isdn4linux under dosemu?
Is there a working ISDN card for a DEC Alpha with Linux?
Can isdn4linux run in parallel to UISDN?
What are AOC-x, CLIR, COLP, CVS, HDLC, HSCX, ISAC, TEI...?

2 Configuration

3 Troubleshooting

3.1 General

My isdn4linux doesn't work! How do I best go about finding the problem?
I have problems compiling isdn4k-utils-2.0. "ncurses.h" or "panel.h" is not found. But curses.h does exist.
Why does neither my telephone nor my fax machine ring when I call them with isdn4linux?
If i4l uses one B-channel then the other one will be blocked (incoming as well as outgoing)...
In the instructions for my NTBA it says that a crossed a/b cable pair has no effect on the operation?
How can I test whether a a/b cable pair has been crossed?
Even though I deactivated the signalling for incoming calls, an incoming caller does not get a BUSY signal, although neither i4l nor any other ISDN device is configured to use that MSN. Even when every usable B-channel is used by i4l or another user an incoming caller will not get BUSY. The same is true when I deactivate audio support for i4l.
When the router is active, incoming calls from customers hear ringing, even when we're on the line with a support call. This gives the impression that our employee doesn't answer the phone.
I closed all ISDN applications. Why can't I unload my ISDN modules ("isdn: Device or resource busy")?
I'm now certain I've closed all ISDN applications. I still sometimes cannot unload the ISDN module ("isdn: Device or resource busy")...
I still can't unload the modules. I use callback.
My charge "impuls typ A" [German charge impulse at the end of a connection] is not correctly transmitted, although the Telekom says they activated it.
My PBX produces a reset on the SO bus every hour, after which isdn4linux no longer accepts any calls?
My Ascotel PBX crashes i4l (connected on my internal bus).
My Teles 16.3 works behind a Quante IS-2 (identical to the Ackermann Euracom 181) after a reset, only when I: 1. unplug the PBX 2. turn off the PC 3. plug in the PBX 4. turn on the PC
I'm connected through an old PBX. Any attempt to dial out is refused with cause 64?
I can't get my PBX, a proprietary Siemens Hicom, to work?
isdnctrl returns a "bus error" when I do a "isdnctrl list"?
After a hangup "no routine" is printed on /dev/isdnctrl. Did it release my line or is there still some bug in the driver?
I get many "HSCX RME out of buffers" messages in my syslog.
My pppd or ipppd has problems with PAP/CHAP authentication.
I get the error "SIOCADDRT: Invalid argument" when telling route to route to isdn0.
I regularly see meesages such as:
isdn: line0,ch1 cause: E0010
What does this mean? Where can I find out the meaning of these causes?
On my ELSA card, the LED for the loss of the TEI often blinks. My connections are also often disrupted...
My isdn driver crashes my machine! Since I've configured it as a module, the addresses change each time it's loaded. How can I find out where the driver is crashing?
My hard disk becomes very active when isdn4linux run. How can I turn this off?

3.2 Teles driver

How can I know that my Teles card (or compatible) is recognized correctly?
What is the name if my Teles driver (especially if compiled into the kernel)?
On bootup I get "HSCX version A:5 B:5" but I still have the impression that my Teles card is not used correctly. What else can I check?
Why should I avoid IRQ 12 and 15 for my ISDN card?
My Teles card will not be recognized correctly when I use LILO with my parameters.
If I first start DOS and the Teles driver included with the card, and then start Linux with Loadlin, everything works fine. However, if I start Linux directly with LILO, the Teles driver doesn't respond directly.
After a reset, my card does not initialize correctly.
The Teles driver recognizes my 16.3 card as a 16.0.
I use i4l and the Teles driver. From time to time the driver hangs and I have to reload it.
My machine often crashes. On the console I get about every few seconds l1state 4 l1state 8 l1state 13 ph_command 9 l1state 4 l1state 0 ph_command 0 l1state 7 ph_command 9
My Teles driver always says "isdn0: Chargesum is 0" although I get charge information from the [German] Telekom.
My Teles driver does not work in 2.1.x!
I have two Teles cards in my computer but it seems that only one is used!
When compiling the Teles driver I get some undefined symbols (only kernel 2.0.26)?

3.3 HiSax driver

How can I tell whether my ISDN card has been corrected recognized by the HiSax driver?
The Teles crashes again and again with the following error message in the log: <date> <time> foo kernel: HSCX B EXIR 10 <date> <time> last message repeated <n> times
My AVM card produces very many interrupts with the HiSax driver. Is this normal or a problem with the HiSax driver?
The PNP tools done work with my Teles 16.3 PNP card!

3.4 ICN driver

On dialing out/in with my ICN packets get lost.

3.5 Working together with other ISDN devices

I have problems connecting to an ELink.
I have problems connecting to a Netblazer router.

3.6 Raw IP

I get the error message "protocol error, unspecified".

3.7 Modem emulation (use with ttyI* devices)

When I dial with "ATD....." I always get a "NO CARRIER".
My modem emulation/pppd does not recognize an incoming call.
I gave the correct MSN/EAZ, but still don't get a RING.
Why can't I dial my telephone or fax with the modem emulation?
I can't get a connection to my ISDN mailbox.
I'm sure I used the correct parameters for my ISDN mailbox, but I still don't get a connection. I always get BUSY although I know the mailbox is not busy.
My modem emulation hangs. How can I force my card to hang up?
During a tty connection, I get a message from the kernel "teles_writebuf: channel not open". Then no more input is accepted for this connection.
When I use UUCP with X.75, I always get transfer errors!
My iprofd doesn't work any more with HiSax 2.0. I get the error message "Version of kernel modem-profile (3) does NOT match version of iprofd (1)". How can I get iprofd to work again?

3.8 Async PPP

How can I get a log for pppd?
Establishing the connection works fine, but pppd crashes just after that (i.e. the first bytes get through, but then everything stops)

3.9 Sync PPP

How can I get a log for ipppd?
My ipppd won't work, it gives the error message "PPP driver 0.0.0 is out of date".
Starting ipppd I get the error message "this systems lacks ppp support".
How can I switch on PPP support for my kernel 1.2.13 (needed for ipppd)?
When I start ipppd, I only get error messages from the i4l driver.
When I try to start ipppd it says "Can't find usable ippp device"
I can't get a connect. How can I find out where the problem is?
ipppd sometimes crashes (kernel 2.0.14...2.0.25)
I get the message "IP frames delayed" - and I don't get a connection.
I cannot dial out with "isdnctrl dial ippp0". It seems as if the route to ipppd is missing although I *did* set it ("network unreachable"). With my old kernel < 2.0 everything works fine!
After ipppd dials out my default route is gone.
When dialing out, I get the message "pppd: peer authentication required but no authentication files accessible." What does this mean?
I cannot establish a connection - it's rejected by the other side. In the log file I find a message that's something like: "sent [0] [LCP ConfReq id=0x1 <mru 1500> <auth pap> <magic 0xcd12e9c4>"
I cannot establish a connection - it's rejected by the other side. In the log file I find a message that's something like: "sent [0] [LCP ConfRej id=0x1 <auth pap>"
I have problems with PAP or CHAP authentication. It does not work although I'm sure I entered passwords etc. correctly.
I often get the error message "hscx_empty_fifo: incoming packet too large"
The connection with ipppd seems to work, but eventually it crashes.
I only have problems with ipppd when the connection is being heavily burdened. Then everything stops. What could be causing this?
My ipppd works, but I keep getting the message pppd[104]: ioctl(SIOCSIFMTU): Invalid argument"?
The first IP packet gets lost on automatic dialout with dynamic IP address allocation.
When calling "isdnctrl mapping <line> <MSN>,..." I get the error "bad address".
What does the message "No phone number, packet dropped" mean?
Why does my ipppd dial one too many zeros ("isdn0: dialing 0 089XXXXXX...")? I don't have any extensions!
My ISDN device is shown with HWaddr and IRQ=0 and base address = 0 when I list it with ifconfig

3.10 ISDN in a network

xosview doesn't show any network activity since installing i4l.
When I for example from a W95 box call up a page with Netscape, I only get the answer "unknown host".
Addresses are now found, but now instead of the page I want I get the message "no route to host".
After booting, my local network can no longer be reached. I use the network interface ippp0 with ifconfig 0.0.0.0; the default route points to ippp0.

3.11 Isdnlog

My isdnlog 2.50 doesn't work since I installed HiSax 1.2.
I've patched isdnlog, but it still won't work together with HiSax (isdnlog starts with the usual messages, but nothing happens)?
Isdnlog (>=2.52) shows for a caller two telephone numbers! Which one is correct?
When calling I receive a "Internal error: wrong structure".
Isdnlog crashes with a "segmentation fault".
I've set up a script to play sound per cat on /dev/sound or some other device. When several events occur, then there is an error: "Can't open output file '/dev/sound': Device or resource busy"
Isdnlog should call a program with redirected output (e.g. "play anruf.au 2>/dev/null" ). Why does ISDN tell me "Can't start '/usr/local/bin/play anruf.au 2>/dev/null' with execvp()"?
Why does isdnlog quit with "kill -1", according to the docs it should only reread isdnlog.conf.
Isdnlog takes 100% of the CPU time
The Telekom is paying me (according to isdnlog/isdnrep) 12 pfennigs (1 unit) for each connection...
According to isdnlog every "busy" costs me 45 units?
I'm having problems getting isdnlog to run with libc 5.4.7!
When dialing out, the screen goes momentarily black?

3.12 Audio

My vboxgetty does not answer any incoming calls.
My vboxgetty answers at the first ring but the number of rings is set to 4.
My vbox 1.1 does not work together with HiSax.
If vboxgetty has recorded a message in a format which can not be played using "cat xxx>/dev/audio" how can I still hear the message?
At the beginning of a message recorded by vboxgetty, there's often a part of my own announcement?

3.13 Dialout on demand

What can cause a charge unit disaster?
Ever since I installed a new kernel, my computer constantly open ISDN connections without transferring any data (expensive!).
My router wants to constantly dial out (and does it too) but NO data is transferred, neither ipfwadm -A! nor tcpdump -i isdn0 show anything.
After closing the line, I discover with "netstat -nt" that IP connections are still open. How can I close these manually?
How can I safely turn off dialout on demand?
How else can I prevent the charge unit disaster?
Is it possible that even with a crashed computer a ISDN connection remains open (and the charge units accumulate)?
How can track down unexplainable dialouts?
Can it be that the Win95 machine on my LAN is causing automatic dialouts?
I have set up a local DNS name server. Why does it cause unwanted dialouts? How can I find the cause?
How can I turn off the DNS requests for WORKGROUP.xxx from my Win95 machine?
How can I get sendmail to not initiate any connections without local mail being left undelivered?
The samba package always triggers dialouts for me. How can I prevent this?
How can I get Netscape to quit initiating dialouts when starting?

3.14 Chargeint

The connection doesn't end with timeout. Possible reason: my service provider uses a Cisco router which sends a "keep alive" packet every ten seconds.
My Internet provider won't switch off keep alive packets so ipppd never hangs up.
The "lcp-keep-alive" patch doesn't work - ipppd still doesn't hang up.

3.15 Dialin

I keep getting the message "isdn_tty: call from XXX -> YYY ignored". Why does isdn4linux (syncPPP) ignore this dialin attempt?
I've configured several ippp* devices. Each incoming call "uses up" one device, until there is no device available any more.
With "isdnctl pppbind" I've established an exclusive connection. But this is removed with an incoming call.
A SunISDN tries to dial into my i4l system.

3.16 Callback

An incoming call is rejected by i4l. i4l then calls back. The reject is not recognized by the other side which keeps on dialing to i4l.
Callback isn't working. How many ippp* devices do I need (at a minimum)?
Callback still doesn't work right. Can the fault lie with the Teles driver?
When trying callback with Euro-ISDN the call never gets rejected.
Somehow i4l can not callback a Cisco?
Callback from an Ascend works only when I set "Active=Yes" in the Ascend menu; but then the Ascend keeps calling me, even when my machine is off.
How can I callback a Banzai!?
Some the callbacks confuse the module count. How can I now unload my ISDN modules?

3.17 MPPP

SyncPPP works without problems on one channel. Unfortunately MPPP won't work due to communication problems between ipppd and the other side.

4 National Peculiarities

4.1 Germany (1TR6)

Which EAZ should I use for i4l?
I use 1TR6 on an extension - the extension number has more than one digit (e.g. 206). What is my EAZ?
The state machine hangs with 1TR6.

4.2 Italy

What does our MSN look like?

4.3 The Netherlands

What does our MSN look like?
How can I get isdnlog to calculate the charges for the Dutch telephone company?
Are there any other peculiarities?

4.4 Austria

We have neither an MSN nor an EAZ, only a normal plain telephone number. What do we have to use for i4l?
Incoming and outgoing calls won't work ("incoming call without CPN")
Why doesn't my getty answer the EAZ it should respond to if somebody dials the "0", the broadcast number? In the log file it says "Incoming call without CPN, assuming '0'".

4.5 Switzerland

We have neither an MSN nor an EAZ, just a plain telephone number. What do we have to use for i4l?
I can only keep a 184 second connection with i4l. After that the connection breaks with cause "Temporary failure" since the telephone company uses new software for its equipment.
How can I get isdnlog to calculate the charges for the Swiss telephone company?

4.6 Portugal

What should we use as MSN?

4.7 North America

Can we use isdn4linux in North America?
Why can't I use European ISDN cards in North America?
Which protocol is used in North America?

5 Miscellaneous

How can I set the clock of my computer with ISDN?
Where can I find information on the dip switches of my NTBA?
Can I connect two ISDN devices directly with a kind of "null modem cable"?
Where can I get documentation on Siemens' HSCX and ISAC chips?
Where can I find the "bat" book about configuration of sendmail?

FAQ for isdn4linux - Version 1.3.3
(translation 3-Oct-97)

[Translator's notes]
--5-May-97: Translation complete for 1.3.2 (except for the proofreading)!
--8-May-97: Added correction for Italy.
--25-May-97: Numerous corrections submitted by Paul Slootman
--27-May-97: Minor cleanup, noted additional countries
--27-Sep-97: Added more translator's notes for various countries and 2.0.30
--3-Oct-97: Added note for MSNs in the UK This FAQ is protected by the GNU General Public License (GPL) Version 2; (C) 1996 Volker Götz, Bernhard Hailer, Matthias Heßler, Michael Hipp and Rainer May.
Distribution under the terms of the GPL is welcome. However, we offer NO GUARANTEES for the information herein. Please read the GNU General Public License for further details. A printed version is available from
Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. An electronic version is available from the authors.

Original FAQ by Volker Goetz <volker@oops.franken.de>, (c) 1995
Comprehensive edition and additions (1996, 1997):
Matthias Hessler <hessler@wi-inf.uni-essen.de>,
Bernhard Hailer <Bernhard.Hailer@lrz.uni-muenchen.de>,
Scott Hanson <shanson@shcon.com> (English translation),
Michael Hipp <Michael.Hipp@student.uni-tuebingen.de> (many syncPPP questions)
Rainer May <r_may@khavi.desaster.heide.de> (i4l and networks)

English translation coordinated by Scott Hanson <shanson@shcon.com> with contributions from:
Sven Tervoort <sveneric@xs4all.nl>
Matthias Hessler <hessler@wi-inf.uni-essen.de>
Erik Corry <erik@arbat.com>
Paul Slootman <paul@wau.mis.ah.nl>

About the format of this FAQ:
The basis of this FAQ is the i4l mailing list. We checked the messages posted to the list and included relevant messages (usually) in the form of quotes. These quotes are not always 100% identical with the original; spelling errors have been corrected, and some messages were translated from English into German. Whoever notices that they have been incorrectly quoted, or would rather not have their Email address noted, please let us know - we'll ... in the next version of the FAQ. The same applies in cases where we have quoted someone without noting it as such. The knowledge of the FAQ authors is noted without quoting ourselves. Remarks from the FAQ authors about quotes are noted like this: [This is a remark - Ed.]
The countless links in this documents are not always complete and with time may no longer be correct. We do not have the time to check them all. If you discover a bad link, please let us know.
In the 7bit version of this FAQ, all new or rewritten questions are marked with a change bar in the left margin. (Does anyone have an idea, how we can mark this in the HTML version?)

Additions, improvements and other suggestions are always welcome (also correction of typographical errors!), preferably send "diffs" from the ASCII version to Matthias and Bernhard. Thank you very much in advance!

This FAQ can be found at:
http://www.lrz-muenchen.de/~ui161ab/www/isdn/
or:
ftp://ftp.franken.de/pub/isdn4linux/FAQ
or:
ftp://ftp.pop.de/pub2/linux/isdn4linux/FAQ

1 General information about isdn4linux

What is isdn4linux?

isdn4linux is a set of kernel modules that "teach" the Linux kernel ISDN. It consists of a main module ("isdn") and the actual hardware drivers that control the specific cards.
What can isdn4linux do?

isdn4linux controls ISDN PC cards and can emulate a modem with the Hayes command set ("AT" commands). The possibilities range from simply using a terminal program to connections via HDLC (using included devices) to full connection to the Internet with PPP to audio applications.
What can't isdn4linux do (yet)?

There is no full duplex audio connection possible. Some protocols are still missing (V.110, American protocols).
Can I use isdn4linux in North America?

See this question in the section "National Peculiarities".
What do I need for isdn4linux?

isdn4linux has been part of the Linux kernel since version 1.3.59. In addition, you need the package isdn4k-utils-2.0.tar.gz and possibly the HiSax driver.

How can I get isdn4linux?

Via FTP:
The package is at ftp://ftp.franken.de/pub/isdn4linux and various mirrors.
Via Modem/ISDN:
From the Linux server of the Incubus BBS (Login gast, cd /pub/linux/isdn4linux, download via ZModem with 'sz filename') . The server can be reached at the following numbers

       +49 931   781464   Zyxel U-1496E      V.32(bis), V.42(bis), Zyxel 19200 
       +49 931   781465   Atrie 1914A        V.32(bis), V.42(bis), V32terbo
       +49 931   781467   Atrie 1914A        V.32(bis), V.42(bis), V32terbo
       +49 931   781468   Atrie 1914A        V.32(bis), V.42(bis), V32terbo

New ringdown (16 Lines. First log in as 'bbs'):

       +49 931 79002055   Motorola 3400      V.32(bis), V.42(bis), V.34

ISDN (also log in 'bbs') :

       +49 931  7840724   ICN                X.75    2 B channels
       +49 931  7841020   ICN                X.75    2 B channels
       +49 931  7841060   ICN                X.75    2 B channels 
       +49 931  7841070   ICN                X.75    2 B channels 
       +49 931  7841080   ICN                X.75    2 B channels

Here is a list of mirrors; thanks to Herbert Rosmanith <herp@wildsau.idv-edu.uni-linz.ac.at> for compiling it initially. Whoever knows of any mirrors not listed here, please let us know!

  ftp://ftp.cs.tu-berlin.de/pub/net/isdn/isdn4linux/
  ftp://ftp.fokus.gmd.de/pub/Linux/isdn/isdn4linux/
  ftp://ftp.franken.de/pub/isdn4linux/
  ftp://ftp.kiss.de/pub/linux/isdn4linux/
  ftp://ftp.leo.org/pub/comp/os/unix/linux/isdn/isdn4linux/
  ftp://linux.mathematik.th-darmstadt.de/pub/linux/mirrors/misc/isdn4linux/
  ftp://ftp.nvg.unit.no/pub/linux/isdn/
  ftp://ftp.pop.de/pub/linux/isdn/
  ftp://ftp.rz.fh-hannover.de/pub/linux/local/isdn4linux/
  ftp://ftp.rz.hu-berlin.de:/pub/linux/isdn4linux/  
  ftp://ftp.tu-dresden.de/pub/soft/isdn/isdn4linux/
  ftp://ftp.uni-mainz.de/pub/internet/starter-kit/isdn/isdn4linux/
  ftp://ftp.uni-wuppertal.de/pub/linux/isdn4linux/
  ftp://ftp.xlink.net/pub/mirror.ftp.franken.de/isdn4linux/
  ftp://fvkma.tu-graz.ac.at/pub/isdn4linux/ 
  ftp://wildsau.idv.uni-linz.ac.at/pub/isdn4linux/

What documents should I read first?

ISDN kernel subsystem:/usr/src/linux/Documentation/isdn/README ISDN cards: /usr/src/linux/Documentation/isdn/README.<card> Synchronous PPP: /usr/src/linux/Documentation/isdn/README.syncppp /usr/src/linux/Documentation/isdn/README.syncPPP.FAQ Voice capability: /usr/src/linux/Documentation/isdn/README.audio ISDN Utilities: /usr/src/isdn4k-utils-<version>/README(.*) Many of the utilities also have man pages! In a Suse distribution the following information might also be helpful: Synchronous PPP: /usr/doc/faq/faq/PPP-FAQ Email configuration: /usr/doc/howto/mini/Mail-Queue.gz

What helpful links are there about isdn4linux?

Scripts and installation tips from several people:
http://www.rosat.mpe-garching.mpg.de/~web/ISDN.html
I4l, syncPPP, email, Usenet, Voicebox, this FAQ and more:
http://www.lrz-muenchen.de/~ui161ab/www/isdn/
Michael Hipp's page (ipppd):
http://www.sfs.nphil.uni-tuebingen.de/~hipp/isdn/
Chargeint instructions:
http://www.provi.de/~gvz/chargeint.html
Stefan Nehlsen's instructions for syncPPP:
http://www.techfak.uni-kiel.de/~stn/i4l/
xled (formerly xvboxled) is at:
fb4-1112.uni-muenster.de/pub/ffwd/
Example configurations for isdn4linux are said to be at:
http://www.datenhighway.com/isdn4linux.html
This FAQ along with isdn4linux is at:
ftp://ftp.franken.de/pub/isdn4linux/
This FAQ is also so:
ftp://ftp.pop.de/pub2/linux/isdn4linux/FAQ
Is there a mailing list for isdn4linux?

Yes, there is. To subscribe, send an email message to "majordomo@hub-wue.franken.de". The subject doesn't matter. The message should read "subscribe isdn4linux <Email address>", where <Email address> is the address to which mail from the list should be sent. Currently there are about 20-50 messages per day.
How can I have myself removed from the mailing list?

To unsubscribe, send another email message to majordomo@hub-wue.franken.de - the subject doesn't matter. The message should read: "unsubscribe isdn4linux <Email address>", where <Email address> is the address to which mail messages from the mailing list had been sent.
Is the mailing list mirrored to a newsgroup?

Yes, the mailing list can also be accessed at de.alt.comm.isdn4linux - a bidirectional gateway makes sure that one can also answer postings.
Is there an archive of the isdn4linux mailing list?

Yes, the messages are saved (unsorted) at hub-wue.franken.de. They are collected by month. To access the archive, send Email to "majordomo@hub-wue.franken.de". The subject doesn't matter. The following commands are possible:
```
     index isdn4linux          - list which archive files are available
     get isdn4linux <filename> - retrieves the file <filename>
```
The archives are named "archiv.<year><month>, so "archiv.9610" is the archive for October 1996. An archive of the mailing list is also available via FTP:
!link ftp://ftp.uni-oldenburg.de/pub/unix/linux/isdn/isdn4linux/Mailing-List; Another archive is available (according to Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de>) at:
http://wws.mathematik.hu-berlin.de/ldr/ISDN/isdn4linux/
In which countries does isdn4linux work?

[Translator's note: I've made some additions to the original list.]
We are aware of the following countries:
```
     Austria
     Belgium
     Finland
     France
     Germany
     Israel
     Italy
     Norway
     Peru
     Portugal
     Spain
     Sweden
     Switzerland
     The Netherlands
     United Kingdom
     USA
```
[Translator's note: I've also seen messages on the mailing list from isdn4linux users in Canada, Denmark, Hungary and Slovenia . I've also seen mentions of isdn4linux from Australia, the Czech Republic and Poland, but I'm not sure if it is actually in use in those countries.]
Is isdn4linux approved for use by the telecommunications authorities?

Germany:
That depends on the driver used. For active cards, the approval covers the entire card including its firmware. Thus the approval also covers the use of these cards with isdn4linux. The Teles 16.3 and the Elsa QS1000 drivers are currently certified in Germany (and hence in most european countries). This applies to the 2.0.36 kernel version.
Other countries:
Besides those countries that accept a german certification, we don't have any information... does anyone know more?
What is the most recent version?

Kernel 2.0.36 contains a very up to date version of the ISDN drivers. We recommend that you use that kernel version.
Together with the 2.0.36 kernel, a new utilities package has been released, which is a MUST (old versions of the utilities will not work with the new kernel). The utilities are available at ftp://ftp.franken.de/pub/isdn4linux/v2.0/ and the current filename is isdn4k-utils-3.0beta1.tar.gz (also available as .bz2). Check first if there is a newer version.
What hardware is NOT supported?

For not (with the exception of ICN) no active ISDN cards are supported, except the AVM B1, for which there an alpha driver as binary only.
Does isdn4linux support external terminal adapters?

No, but it doesn't need to. Terminal adapters are designed to behave either like a modem or like a network card. Linux already supports both modems and network cards without isdn4linux - so no special ISDN driver is necessary (which usually greatly simplifies the configuration),
Which internal cards are supported?

Right now there is a driver for all card with a certain Siemens chip set (HiSax driver), that also supports Plug&Play cards. See the next question for details.
The HiSax driver has superseded the old Teles driver, which is therefore is not being further developed. For this reason, the Teles driver has many more bugs and should not be used any longer.
Further drivers includes that for the (active) ICN card (ICN driver), as well as that for the PCbit card (Octal, Portugal).
There used to be a (special) driver for the ITK ix1 micro" from Frank Mohr <mohr@fhdacom2.fhrz.fh-darmstadt.de>, but that is not included in HiSax 2.0. It supports the following cards:
```
       * ITK ix1 micro V2.0 and V2.1
       * Cisco 200
       * ITK Columbus
```
Finally there is also a (alpha) driver for the active AVM B1, with its own peculiarities. See the question "What about the active AVM B1?".

What is the new HiSax driver all about?

It is a new driver that should support all passive cards that are based on a certain Siemens chip set. Currently it supports:

* Teles 8.0/16.0/16.3 and compatible ones * Teles 16.3c * Teles S0/PCMCIA * Teles PCI * Teles S0Box * Creatix S0Box * Creatix PnP S0 * Compaq ISDN S0 ISA card * AVM A1 (Fritz, Teledat 150) * AVM Fritz PCMCIA * AVM Fritz PnP * AVM Fritz PCI * ELSA Microlink PCC-16, PCF, PCF-Pro, PCC-8 * ELSA Quickstep 1000 * ELSA Quickstep 1000PCI * ELSA Quickstep 3000 (same settings as QS1000) * ELSA Quickstep 3000PCI * ELSA PCMCIA * ITK ix1-micro Rev.2 * Eicon.Diehl Diva 2.0 ISA and PCI (S0 and U interface, no PRO version) * Eicon.Diehl Diva Piccola * ASUSCOM NETWORK INC. ISDNLink 128K PC adapter (order code I-IN100-ST-D) * Dynalink IS64PH (OEM version of ASUSCOM NETWORK INC. ISDNLink 128K adapter) * PCBIT-DP (OEM version of ASUSCOM NETWORK INC. ISDNLink) * HFC-2BS0 based cards (TeleInt SA1) * Sedlbauer Speed Card (Speed Win, Teledat 100, PCI, Fax+) * Sedlbauer Speed Star/Speed Star2 (PCMCIA) * Sedlbauer ISDN-Controller PC/104 * USR Sportster internal TA (compatible Stollmann tina-pp V3) * ith Kommunikationstechnik GmbH MIC 16 ISA card * Traverse Technologie NETjet PCI S0 card * Dr. Neuhaus Niccy PnP/PCI

Note: PCF, PCF-Pro: up to now, only the ISDN part is supported PCC-8: not tested yet Teles PCMCIA is EXPERIMENTAL Teles 16.3c is EXPERIMENTAL Teles PCI is EXPERIMENTAL Teles S0Box is EXPERIMENTAL Eicon.Diehl Diva U interface not tested

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 14 Oct 1996:

     The first goal of the HiSax driver was to add support for more ISDN
     cards to i4l, and this goal remains. Secondly, it should be as simple
     as possible to configure and not appear to work when there is a
     hardware problem (IRQ, reset problems with Teles). I can't fix the
     hardware problems directly, but driver will not load if such problems
     appear. Third (this part has just now begun) is to fully rewrite the
     state machines into a complete DSS1 or 1TR6 that could be approved
     (which doesn't mean that I personally can or want to obtain approval).
     In addition, if possible I'd like to support US ISDN protocols, so
     that i4l can be used outside of Europe. Also, further l2/l3 protocols
     should be added (e.g. V110), leased line support.... a lot of work,
     that I'm sure I cannot do alone. Anyone with any knowledge of
     programming and ISDN (I myself first heard of ISDN in January, and my
     work has nothing to do with ISDN... I learned everything on my own
     time), and anyone who wants to help can contact me.

What about the active AVM B1?

Andreas Schultz <aschultz@hppool.cs.Uni-Magdeburg.de> has written a driver, that can be found (as an alpha version at: http://www.cs.uni-magdeburg.de/~aschultz/avmb1-1.2-alpha.tar.gz Because he had to sign an NDA, the driver is available only as a binary.
Now that my AVM produces so many interrupts with the HiSax driver, which is the best passive card to use with HiSax?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 12. Nov 1996:
It shouldn't make that much difference. As for the load on the system, the Fritz! is probably the worst in the long run [see also the question "My AVM card produces very many interrupts" in HiSax part if the Troubleshooting section], but maybe I can get that right with the timer, since that's only noticeable when, for example, the system busy with rendering for an entire night.
Karsten Keil <keil@temic-ech.spacenet.de> wrote further on 2. Dec 1996 on stability and lack of bugs:
```
        1st choice ELSA
           ELSA (as opposed to AVM) makes the specifications available.
        2nd choice Creatix PNP
           Creatix employees are also not completely negative towards Linux ;-). 
           By the way, this card has been developed by Creatix and
           is not identical to the Teles 16.3 PNP.
```
Does isdn4linux support external ISDN adapters?

No, isdn4linux supports only internal cards. External ISDN adapters can be accessed either like an analog modem or like a network card, and therefore do not need isdn4linux.

Which ISDN modes are supported?

    56k asynchronous : no
    64k synchronous  : yes
   128k synchronous  : yes (channel bundling - see the next question)

Does isdn4linux support channel bundling?

The current version of isdn4linux support 2 methods of channel bundling:
- MPPP (based on sync PPP)
- Raw bundling (configured by so-called slave channels)
Both variants have their own advantages and disadvantages See the question " How do I use channel bundling?" in the "Channel bundling" section below.
Warning: Channel bundling saves time, but not any telephone charges. Only if you really need the extra bandwidth is it useful.
What is the difference between an active and a passive ISDN card?

An active ISDN card handles most of the ISDN connection protocols (dialing, accepting calls, etc.) itself. The card includes a kind of minicomputer with its own software (firmware). With a passive card, the computer in which the card is installed has to perform these functions.

Are there sites that offer guest access where I can test my isdn4linux setup?

Yes, the following sites offer guest access for modem emulation or IP:
- Eberhard Moenkeberg <emoenke@gwdg.de>:

     * Welcome to Linux at eberhard.moenkeberg.de (LAN, 192.168.99.1).
       Under ++49-551-7704103, ISDN NetCalls (HDLC-trans-rawip)
       for 192.168.99.1 get accepted. You should come as 192.168.*.*
       because sometimes my "default" route is not your way.
       /ftp is exported for NFS; try "showmount -e".
       You can login as "guest" without password.
       FTP as "gast" with password "gast" avoids the restricted shell.
     * Under ++49-551-7704102, a 28800 bps modem and a Creatix ISDN 
       card (HDLC only, not X.75) are listening for logins.

With the net setup from
ftp://ftp.gwdg.de/pub/linux/isdn/isdn4linux-gwdg/rc.isdn-Beispiel
you can test NetCall at 551-7704103 (works as is within Germany, from outside Germany you just have to change the number).
- Gernot Zander <hifi@scorpio.in-berlin.de>:

     There's a "gast" at +49 30 67 19 81 01 (X.75, mgetty). There's the 
     stones-html-page with pics in postscript to test downloading. Whoever
     needs a target to call can use it. At ...81 03 there's a getty with
     HDLC. As guest you enter a kind of BBS  and can read some news.

Can I combine isdn4linux with diald?

Yes, see the "Diald" part of the "Configuration" section.
Can I use isdn4linux as an answering machine?

Yes, voice support is possible with the current version of isdn4linux. You can either use "vgetty" from Gert Doerings "mgetty+sendfax", or "vboxgetty" from Michael Herold, which is made especially for isdn4linux. The latter can be found at: ftp://ftp.franken.de/pub/isdn4linux/contributions/
Can I fax with isdn4linux?

Several groups are working on fax software that will work together with isdn4linux. At the moment, it looks like it will never work... because timing is critical for fax software, and Linux doesn't yet have a real time environment. If you do want to fax, you'll have to install an analog fax modem along with your ISDN card.
Is videotex/Btx/Datex-J possible with isdn4linux?

Yes, it works with the modem emulation with the ttyI* devices. There is a special register to set for videotex (ATSx=y - see the Readme's) It's also possible to access the Internet via the German T-Online. Warning! XCept (formerly Xbtx) has an ISDN configuration option. This should NOT be used. XCept should be configured as if a normal modem were being used.
See also the questions about T-Online in the "Configuration" section.
Can I connect to Compuserve with isdn4linux?

No, because Compuserve's ISDN dialin works only with the old V.110 protocol. V.110 is not (yet) implemented in isdn4linux. In the meantime, Compuserve offers several X.75 numbers.
Which ISDN features can not be offered by isdn4linux?

Some ISDN features are device-specific and cannot be activated by isdn4linux for other devices, unless isdn4linux were to falsify the TEI (which would probably confuse the other device). Such device-specific ISDN features are, among others: rejection of a waiting call, caller id on/off, hold, conference calls, call forwarding, differing COLP/CLRP.
I'd like to write a new hardware driver. Where can I find a description of the interfaces to the link level module?

In the kernel source (in /usr/src/linux/Documentation/isdn) you can find the file INTERFACE - it is the description of the interfaces to the link level module.
How can I access the source from the current development/what is the CVS tree all about?

CVS - Concurrent Version System
This is a multiuser/server extension to RCS (Revision Control System). The I4L drivers are developed under CVS, and there exists on server (oldhades.think.de) a CVS tree to which all developers have access. In addition, Fritz has put together an anonymous read-only access. If you must have the very newest versions, you can get them there, however they may contain more bugs than the released versions!!! Here is the message from Fritz Elfert <fritz@wuemaus.franken.de> about this:
ANOTHER IMPORTANT THING:
I often get patches - against current official releases of course - where i have problems applying them. My local source here sometimes is 2 or 3 version ahead however i cannot release it, since it is incomplete or completely untested etc.
Therefore i now decided to make the CVS repository of the isdn4linux public available. Now, programmers who want to have a look at the development ongoing or those who always want to get the newest stuff here is how to access the CVS repository:
1. Install GNU CVS (any version >= 1.6 will do)
2. create a small shellscript .cvsrsh in your homedir:
```
       #!/bin/sh
       exec rsh -l guest $*
```
3. Set CVS_RSH to this script (e.g.: export CVS_RSH=~/.cvsrsh)
4. Set CVS_ROOT to oldhades.think.de:/i4ldev
(e.g.: export CVS_ROOT=oldhades.think.de:/i4ldev)
5. Execute "cvs -z9 checkout isdn"
-> This will create a directory tree isdn/ in your current directory.
Below isdn/ you will find the same hierarchy like in the linux source plus some scripts to copy/diff the stuff into the linux source tree.
Similar access is available for the utility package with the command:
```
   cvs -z9 checkout isdn4k-utils
```
WATCH OUT!!! THE NEWEST STUFF SOMETIMES IS REALLY INSTABLE OR EVEN DOES NOT COMPILE WITHOUT PROGRAMMING KNOWLEDGE - No newbies questions on this PLEASE! Use the source, Luke!
Note:
Of course the public access is readonly. Access is limited to the following cvs commands:
```
       checkout
       diff
       export
       status
       update
```
See the CVS-doc for how to use these commands.
People who want to help _continuously_ developing isdn4linux by writing new driver etc. can get a real account for full access. Write me a mail in this case.

Can I use isdn4linux under dosemu?

Yes, you really can! Steffan Henke <henker@informatik.uni-bremen.de> wrote on 25 Oct 96:

     In dosemu.conf it is enough to enter a virtual com port,
       (for example com2) that can be used with e.g. Telix or
       Terminate: serial { com 2 device /dev/ttyI3 }
     Access with Fossil is possible if fossil.com (included with
     dosemu) is started.  Tested with the following configurations: 
     - Kernel 2.0.21, Teles driver incl. Karsten's patches 
     - Kernel 2.0.21, HiSax

Is there a working ISDN card for a DEC Alpha with Linux?

Thomas Bogendoerfer <tsbogend@alpha.franken.de> wrote on 17 Dec 1996:
I use an ICN ISDN card in my Alpha Noname for Internet access and mail/news via UUCP.
I don't have a passive ISDN card to test HiSax with Linux/Alpha . There are problems with the timers (HZ is 1024 on the Alpha). Even the ICN driver has the "wrong" Timer, which causes a little too much poling of the card (but leads to better ping times:-)). I suspect that this can be fixed in time.
Paul Slootman <paul@wurtel.demon.nl> wrote:
The current HiSax driver should work with most cards. I myself use a Fritz! Classic (AVM-A1) card in my XLT-300 all the time without any problems whatsoever.

Can isdn4linux run in parallel to UISDN?

Nils Rennebarth <nils@nus.de> wrote on 10 Dec 1996:

        They run parallel. And they run under 2.0.X.
        Both ISDN packages load the module isdn.o, otherwise the naming conventions
        are different. Tip: rename Urlichs isdn.o to uisdn.o ,
        and change lib/modules/modules.isdn (or whatever the file is called
        that lists the modules and is read by the script) accordingly.
        Happily the default names of the ISDN devices are also different.

What are AOC-x, CLIR, COLP, CVS, HDLC, HSCX, ISAC, TEI...?

Here is a small glossary:
AOC-D

        "Advice Of Charge During the Call".

AOC-E (Advice of Charge at the End of the Call)

        "Advice of Charge at the End of the Call". In Germany, this service 
        is included in the "Komfort" connection.

CLIR (Calling Line Identification Restriction)

        CLIR (Calling Line Identification Restriction) can be offered by
        the ISDN provider: one can (from call to call) restrict the identification 
        of one's own caller ID to the other party. In Germany, this must be applied 
        for but is without charge (however call by call transmission of the 
        caller ID costs extra).

COLP (Connected Line Identification Presentation)

        COLP can also be offered by the ISDN provider. In Germany, it must be
        applied for, and costs an extra 10.-- DM per month. If you've applied
        for COLP, you get an extended dialing protocol that, for example, can be
        evaluated in the PBX. Current the possibility is being worked on to get 
        around this with the help of a backwards-connected Teles card. One could 
        then get more information than with a running COLP without using any units. 
        That could quickly pay off...

CVS Tree

        The i4l developers have formed a team. The tool "CVS" allows the members 
        to easily make patches. The history of the project is also thereby 
        documented, and it is also not difficult to reproduce older versions.

HDLC

        A widely used low-level protocol.

HSCX

        A Siemens chip, that similar to ISAC is on many passive cards.
        It takes over the serial bus from ISAC and demultiplexes when 
        receiving  or multiplexes (i.e. inserts the bits in the correct
        position) the B channels.

ISAC

        A Siemens chip, that similar to HSCX is on many passive cards.
        Et is responsible for "Level 1", so it sits (almost) directly on
        the line. It handles the D channel protocol and sends the
        S0 data to a special serial bus (IOM). When sending it does the
        opposite.

TEI (Terminal End Identifier)

        The local switching station, or with an internal S0 the PBX, automatically 
        or permanently assigns each end device a TEI. This simply allows 
        the addressing of the D channels. TEIs have the following values:
         0- 63   permanent TEIs (e.g. 0 is used for PBX connections)
        64-126   automatically assigned
           127   call for all (e.g. an incoming call)

PBX (Private Branch eXchange)

        A PBX is used to connect different internal devices to the 
        ISDN network. This is usually for analog devices.
        that cannot be directly connected to an ISDN network.
        The PBX can also make an internal digital S0 bus available,
        on which ISDN devices can be connected.

2 Configuration

2.1 General

Where can I find scripts and other information on configuring i4l?

Configuration examples and scripts:
http://www.rosat.mpe-garching.mpg.de/~web/ISDN.html
Many HowTo's on basic installation, syncPPP, Email setup, Usenet News, answering machine, and more:
http://www.lrz-muenchen.de/~ui161ab/www/isdn/
Further FAQs with example scripts:
http://www.fzi.de/sim/people/trautw/i4l/index.html
How many ISDN cards can I stuff into my computer?

Just as many as there are ISA slots and interrupts/IO addresses. The Teles 16.3 can use only 3 different IO addresses, therefore you can use at most 3 cards. They each would also need an interrupt.
Peter Strunk <webadmin@mail.bicos.de> gave the following tip on 8 Nov 1996 for installing a fourth Teles card:
```
        Try out port 0x080h, DIP-SW in the undocumented
        position!
```
The AVM is similar.
The ICN has no interrupts, a more flexible port configuration and the driver places the shared memory area of all ICN cards at the same address. The card memory is shown only as needed.
Therefore, one could use as many cards are there are slots... one could even increase the number of ISA slots with an ISA bus extender.
Do I need a DOS setup program to setup my Teles card?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 21 Feb 1997:
You don't need a DOS setup for Linux, with one exception:
Teles once offered a Charge PnP card that did not do PnP correctly. These card can be recognized in that the have NO jumper/dip switch, but are not recognized by isapnp .
All other cards are configured with the Linux drivers or with isapnp
Does the driver support "dial on demand"?

Yes. If a network interface (e.g. "isdn0") is set up, the driver will dial the number. If in addition a hangup timeout (Idle Timeout) has been given, isdnctrl huptime <interfaceY> time, then the driver will automatically hang up when no data was been transferred over the interface for "time" seconds. However, with syncPPP there are problems (see the syncPPP section).
Also look at the dialmode description (next question).
When an IP packet should go over the link (which usually triggers a dialout), all I see in the log is:
dial rejected: interface not in dialmode `auto'

The new ISDN drivers in 2.0.36 defaults to manual dialmode, not autodial. This is done to prevent unexpected (and unnoticed) dialouts.
To enable autodial for a given interface e.g. ippp0, use
```
	isdnctrl dialmode ippp0 auto
```
You can also use the name "all" for the interface to change the setting for all interfaces.
The meaning of the values for dialmode are:
"off"
means that you (or the system) cannot make any connection (neither incoming or outgoing connections are possible). Use this if you want to be sure that no connections will be made.
"auto"
means that the interface is in auto-dial mode, and will attempt to make a connection whenever a network data packet needs the interface's link. Note that this can cause unexpected dialouts, and lead to a high phone bill! Some daemons or other pc's that use this interface can cause this. Incoming connections are also possible.
"manual" is a dial mode created to prevent the unexpected dialouts. In this mode, the interface will never make any connections on its own. You must explicitly initiate a connection with "isdnctrl dial isdn0". You _must_ also hangup the line explicitly as well! There is NO timeout in this mode. Use "isdnctrl hangup isdn0" to end the connection.
"manual" is the default.

Does isdn4linux support PNP (Plug and Play)?

Yes, but only with the HiSax driver. With "Plug" alone it's unfortunately not yet ready, more work is necessary: (from Karsten Keil <keil@temic-ech.spacenet.de>)

        1. HiSax has to be patched into the kernel
           (Attention: use the "-pn" parameter!)
        2. With "make menuconfig" (or "make config") set the following
           kernel options :
             * ISDN = "M" (as module - otherwise PNP doesn't work!)
             * HiSax = "M" (as module - otherwise PNP doesn't work!)
             * 16.3/PNP support
             * EURO support
        3. Compile and install kernel and modules, depmod. (Reboot!)
        4. Read the configuration of the PNP card with:
           "pnpdump > /etc/isapnp.conf".
        5. The configuration file "/etc/isapnp.conf" has to be set by hand.
           Set the following values:
             INT0 - the interrupt used by the card
                  (Default for Teles 16.3 PNP: 10)
             IO0, IO1 - the IO ports used by the card
                  (Default for Teles 16.3 PNP: 0x580 and 0x180)
                  (Attention: these values must be 64-bit aligned! Early
                  versions of the PNP cards my suggest incorrect values!)
        6. Activate the configuration with:
           "isapnp /etc/isapnp.conf"
           (must be started at every boot)
        7. Now the HiSax module can be started with:
           "modprobe hisax io=4,<P>,<INT>,<IO0>,<IO1>"
             4     - PNP card
             <P>   - Protocol:
                       2 - for Euro-ISDN (normally)
                       1 - for 1TR6-ISDN (German predecessor to Euro-ISDN)
             <INT> - the value in etc/isapnp.conf for INT0 
             <IO0> - the value in etc/isapnp.conf for IO0 
             <IO1> - the value in etc/isapnp.conf for IO1

Is there a trick to sometimes boot Linux with ISDN and sometimes without?

Yes, you can use the run level for this (under SysVinit). Emil Stephan <ste@esqhen.su.eunet.de> has written scripts:

     On my computer I've defined 2 run levels (3 and 4), 3 runs without ISDN,
     4 with. If I want to quit ISDN with all the associated processes like
     ipppd, isdnlog and mgetty, as root I enter "init 3"; and to start "init
     4". init then makes sure with "/sbin/init.d/i4l start" or 
     "... stop" that the necessary things are done.

Is it possible to initiate call forwarding with i4l?

Karsten Keil <keil@temic-ech.spacenet.de> wrote that there are plans to later implement this in the HiSax driver.

Has anybody routed ipx/spx over ISDN with Linux?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 14.10.1996:

     That's no problem -  we've done that for a while now.
     - Simply set up an ISDN interface.
     - Important: encap isdnX ethernet
     The rest is done by "mars_nwe" (incl. routing).

Can I use kerneld to load the ISDN modules in the kernel as needed?

Emil Stephan <ste@esqhen.su.eunet.de> wrote on 15 October 1996:

     By default, kerneld unloads a module after it has not been needed for one
     minute. This is no problem for device drivers ala floppy, etc., but it is
     a problem for drivers that need to keep settings over a longer period 
     of time, e.g. the mixer settings for a sound card or the configuration of
     dialin and dialout parameters for ISDN. Unloading the ISDN drivers also
     kills the IP interface ippp0 or isdn0. The entries in the IP layer of the
     kernel then disappear. If you look in the start-up scripts for i4l,
     you'll a lot of things that are configured with isdnctrl, etc.; they
     would have to be reconfigured by kerneld each time the module is
     reloaded. The status of the D channel could also be lost. Therefore, my
     recommendation is not to use kerneld, rather load the modules at start-up
     and only unload if necessary for some technical reason.

See also the question "Is there are trick to sometimes boot Linux with ISDN and sometimes without?".
Markus Gutschke <gutschk@uni-muenster.de> wrote:

     For some time now there has been an extension to the modules package just
     for this purpose; it allows the installation of a databank with the
     current status of the modules. Unfortunately, this feature usually not
     supported by the modules. An alternative are such options as the
     "post-install" hook in "/etc/conf.modules". It would then be necessary to
     write the appropriate scripts by hand, but in principle that would work
     just as well as the modules automatically using the initializations
     settings from a database.

How can I get a tcpdump patched for ISDN?

Michael Stiller <michael@toyland.ping.de> wrote on 23 Oct 1996:
Tip for ftp:
ftp://ftp.gwdg.de/pub/misc/isdn/linux/isdn4linux-gwdg
There is the patch: "tcpdump-3.0.4-1-isdn.dif.gz"
and the rest is at:
/pub/linux/mirrors/funet/PEOPLE/Linus/net-source/tools/tcpdump-3.0.4-1.tar.gz
You might need to hack some, depending on the name of your ISDN interface (mine is bri0). By default, it recognizes only isdn* and isdnY* as interface names.
Henning Schmiedehausen <henning@pong.iconsult.com> further wrote on 30 Oct 1996:

        After finding the patch from Eberhard Moenkeberg at ftp.gwdg.de cannot
        dump cisco HDLC, I made my own patch for
        tcpdump-3.0.4 that asks the interface which
        encapsulation it used and sets itself accordingly. The patch is
        against a tcpdump-3.0.4-1.tar.gz distribution, for example at
          ftp://ftp.funet.fi/pub/Linux/PEOPLE/Linus/tools. 
        This patch recognizes rawIP, ISDN-IP and CISCO-HDLC and can
        dump these packets.

[The patch was attached to the message - it should be easy to find in the mailing list archive - Ed.]
Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> gave the following tip on 5 Nov 1996:

        This is a isdn4k-utils-2.0/tcpdump-3.0.3-isdn.diff ! It work,
        if one makes some changes:
        In the file tcpdump-3.0.3-isdn/libpcap-0.0/pcap-linux.c after patching
        you find the following:
            else if (strncmp("ppp", device, 3) == 0)
        Either you name your ppp devices pppX instead of ipppX, or
        change this line, e.g.
            else if (strncmp("ippp", device, 4) == 0)
                              ^^^^          ^^
        Then tcpdump will also recognize syncPPP. At least it does for me.

How can I set up user permissions for the use of ISDN?

Henner Eisen <eis@baty.hanse.de> wrote on 13 Feb 1997: Access to isdn-ttys can be restricted (following the Unix philosophy) be establishing a group (e.g. 'isdn') in /etc/group, and then
```
       chgrp isdn /dev/ttyI* /dev/cui*
       chmod o-rw /dev/ttyI* /dev/cui*
```
Then all users not in the group 'isdn' have no reading or writing privileges for the ISDN ttys. Those allowed to use ISDN have to be explicitly added to the group 'isdn'.

2.2 MSN

What is an MSN?

Unlike a normal telephone connection, an ISDN connection can have more than one telephone number - each of these is called an MSN. MSN is an abbreviation for Multiple Subscriber Number.
What is an EAZ?

This is a German name for an MSN. In Germany, EAZ and MSN are used as synonyms, though in theory one ought to differentiate according to the protocol used. That which is called MSN in the Euro-ISDN protocol was called EAZ in the German 1TR6-ISDN protocol (a German predecessor to Euro-ISDN).
How many MSNs do I need if I want to do the following:
* Telephone * Analogue modem (used for data, fax or voice mailbox) * Dialin for X.75 (modem emulation) * Dialin for syncPPP

One!!!
The two different types of dialin can be recognized using the 'Service Recognition' code ("digital, data"). If correctly configured, the two different types of dialin can also be differentiated (see the question "Can I use just one MSN both for customers that need a getty (modem emulation) and also for customers that need a direct network connection?" in the section "Dialin").
On the subject of the parallel use of both telephone and analogue modem, Gernot Zander <hifi@scorpio.in-berlin.de> had the following tip (Dec. 11 1996):
Configure fax-getty for 10 rings. If you take the phone and hear a fax or modem, you send a USR1 signal (kill -USR1 mgetty-pid) to mgetty, and it will take the call.
If your phone socket is correctly wired, the modem will take over the connection, cutting off the phone (e.g. a TAE NDN socket and the original cables. If your modem has a dial-blocker, that may get in the way, unless you know the code to switch it off).
[With a suitable modem, mgetty can work as answering machine, and fax machine and data modem - Ed.]
Or: if you have an ISDN PABX that allows call forwarding. You can even daisy-chain these if you run out of analogue ports.
[Despite this, you will find life simpler if you can give the telephone and modem separate MSNs (the ideal solution if you have at least 2 MSNs) - Ed.]
What is my MSN?

Your telephone company will tell you your MSN. It is your own telephone number. The following questions, together with the chapter on national peculiarities deal with the finer points of MSNs under isdn4linux.
How do I tell the modem emulation what my MSN is?

For the modem emulation you use the command AT&E<msn>, which requires the MSN without the area code (except in the Netherlands).
How do I configure my MSN using syncPPP?

The MSN for network operation is set up with the command "isdnctrl msn <interface>". The MSN is given without the area code (except in the Netherlands).
Where should I configure my own MSN in order to test syncPPP by calling myself?

If you want to call yourself as a test then you have to configure your MSN both as the outgoing and the incoming number.
The configuration of the outgoing number is done with "isdnctrl addphone <interface> out <msn>". You must use the MSN including area code (including the "0" at the start - Deutsche Telekom needs this in order to dial correctly). "isdnctrl delphone" is used similarly.
The configuration of the incoming number is done with "isdnctrl addphone <interface> in <msn>". The MSN must be entered in the form in which it is transmitted to the called party. For Deutsche Telekom, this is the MSN including the area code but without the "0" at the start. "isdnctrl delphone" works similarly.
You may find national differences here (see the chapter "National Peculiarities"). See also the following question in case of doubt.
How can I find out how my telephone number is transmitted to the calling party?

The transmitted MSN can simply be determined, by calling yourself (for example by telephone). In the log files you will find the entry that looks like: "isdn_tty: call from XXX -> YYY ignored" (in order for this to work, you must of course already have the ISDN drivers in your kernel and active).
Can I do the following on *THE SAME* MSN:
- Telephony (voice) - VBOX (voice, of course) - X.75 login (mgetty, /dev/ttyI?) - IP interface for IP connections to other computers?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on this subject Dec. 4 1996:
Yes. However, IP dialin cannot be differentiated from X.75 dialin, so you are either restricted to dialout, or you must enter the MSN of the other party and set secure to on. Then the driver will start by asking the net interfaces, and if none match, the call will be handed on to the ttyIs. If someone wants to have the choice between calling you with X.75 or with IP, they will have to use different outgoing MSNs to call you from.
How can I minimize the number of MSNs needed for dialin?

See the question in the chapter on dialin.
How do I set the MSN in a Cisco?

With "isdn answer1 :<msn>" (or answer2). E.g. "isdn answer1 :12345" will set the MSN to 12345.
Why don't I always receive from the German Telekom the number of a caller ("Caller ID")?

For data privacy reasons, telephone numbers from the analog network are are transmitted unless the caller has explicitly allowed the Telekom to do so (costs nothing) and is connected to a digital switching office
Those with an ISDN connection, on the other hand, must explicitly deny permission for the Telekom to transmit the number, or apply to be able to do this on a call-by-call basis [CLIR]. Call-by-call denial is free; call-by-call transmission costs extra. However, it seems to be very difficult for the Telekom to configure this correctly on the first try. If you depend on the transmission of Caller ID, you should check closely that everything is configured correctly.
Do I receive the Caller ID from foreign calls (German Telekom)?

Yes, with calls from countries that don't view Caller ID quite as strictly as does Germany (e.g. USA, Canada).

I've heard that actually two Caller IDs are transmitted?

That's right, there's one that is "User-Provided, not screened", and the other is "Network-Provided" (from the telephone company).
Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 15 Dec 1996:

        The first comes from the PBX and is not checked.
        The second is that assigned by the Telekom.
        Here I had calls where a Siemens employee from Munich called
        in with a long Caller ID with a Berlin area code (030).
        I called the Telekom to ask what was going on; they didn't know
        either until they found somewhat competent who told me that
        it's allowed.

About "no screening" wrote Ralf G. R. Bergs <rabe@Informatik.RWTH-Aachen.de> on 16 Dec 1996:

        "CLIP no screening". The caller has the feature (which costs extra 
        and is only available with the "Komfort" PBX connection(!)), 
        that allows him to transmit any Caller ID he chooses.

2.3 Teles driver

I use SETUP.EXE under DOS, to configure my Teles/Creatix with memory xxxxx and IRQ yy. How do I do this under isdn4linux?

You can enter do this by entering the correct kernel options at boot. It is not recommended that you compile them into the kernel, however i may be necessary in some cases when software conflicts occur or if you have several Teles cards in one machine. In this case you should edit "/usr/src/linux/drivers/isdn/teles/config.c" to reflect the correct settings for your card(s). (read comments in that file)

I'm confused: according to the documentation, my Teles card is configured for IO address 0x180. In Linux (and also in some Windows programs) the address is shown as 0xd80?

The card uses both IO addresses! Karsten Keil <keil@temic-ech.spacenet.de> wrote on 3 Jan 1997:

        The addresses actually used are:
          isac 980
          hscx 180/580
          cfg  d80
        The confusion is the result of a misunderstanding. Teles gives the
        HSCX0 address as a reference, while the old Teles driver needs the
        cfg address. Since users were confused by this, both driver can 
        now use either address (which confuses the users even further ;-))

When compiling the Teles driver I get an error similar to: too many arguments to function '_get_free_pages_R5243d78b'?

From a certain kernel in 1.3.x the calling of kernel function get_free_pages was changed. You are using an old kernel. In this case you should the following line in teles/teles.h
```
     #define NEW_GET_FREE_PAGES
```
comment out
```
     /* #define NEW_GET_FREE_PAGES */
```
I'm using kernel 1.3.x, the Teles driver compiles fine, all the correct parameters are set in config.c, but the card still won't work.

From a certain kernel in 1.3.x the timer was altered. You should comment out the #define NEW_TIMERS line in teles/teles.h.
```
     /* #define NEW_TIMERS */
```

Is it possible to have more than 1 Teles card in one computer?

Yes, it is. All the parameters should be entered in teles/config.c.

     struct IsdnCard cards[]={
       { (byte *)0xd0000,11,0xd00,NULL } ,
       /* 1. Karte */ { (byte *)0xd8000,10,0xe80,NULL } ,
       /* 2. Karte */ ...
       /* u.s.w. */
     };

On 6-10-1996 Christian Kratzer <ck@toplink.net> suggested (lines beginning with "io=" belong at the end of the previous line):

     # load modules
     /sbin/modprobe isdn.o
     echo "teles0 - Teles S0/16.2"
     /sbin/insmod $MODPATH/misc/teles.o -o teles0 teles_id=teles0 
       io=0xd0000,5,0xd80,2
     echo "teles1 - Teles S0/16.2"
     /sbin/insmod $MODPATH/misc/teles.o -o teles1 teles_id=teles1 
       io=0xd2000,9,0xe80,2
     echo "teles2 - Teles S0/16.2"
     /sbin/insmod $MODPATH/misc/teles.o -o teles2 teles_id=teles2 
       io=0xd4000,12,0xf80,2
     /sbin/lsmod | grep teles > /dev/null

How can I tell whether or not my Teles card is recognized correctly?

During booting a message "kernel: HSCX version A:5 B:5" and "kernel: channels 2" should appear. A:4 B:4 is also okay. Other values (in particular A:0 B:0 or A:f B:f) mean the card is not recognized correctly.
Also check under Troubleshooting Teles.
Where can I send complaints to Teles?

At the Email address "vertrieb@teles.de". They also have WWW pages: http://www.teles.de/
Karl Heinz Kremer <khk@specht.stuttgart.netsurf.de> added on 2 Jan 1997:
```
        If you want to read more about Teles's business practices, look at
          http://www.inx.de/~chris/isdn.htm 
```

2.4 HiSax driver

Where can I find the HiSax driver?

At ftp.franken.de /pub/isdn4linux/HiSax.
Which version is current?

Version 1.4.

How is HiSax better as the original Teles driver?

Karsten wrote to the FAQ team on 14.Oct.96:

     HiSax checks the hardware and the behavior of the IRQ, so that the  
     driver will only be loaded if it can access the register and the
     interrupts can be generated. 
     THEREFORE:
       loading twice is taken care of
       HSCX version 0 or F is taken care of
       BUSY with minicom only if :
       * REALLY BUSY
       * no MSN/EAZ
       * cable/line problems

So, isn't that something?

How do I install HiSax?

Karsten Keil <keil@temic-ech.spacenet.de> described like this:

     It can never hurt to first backup the original kernel sources.
     Then go to /usr/src/linux (where the current source should be.
     The patch itself:
       zcat HiSax_1.1.patch.gz |patch -p1 >& /tmp/HiSax.log
     The -p1 is very important, otherwise all files will end up in new 
     directories under /usr/src/linux.
     Then look at /tmp/HiSax.log for errors/warnings/rejects, if there are 
     any then look at those files and correct by hand, if necessary.

Uwe Bonnes <bon@elektron.ikp.physik.th-darmstadt.de> added:

     If you have Gnu Patch, you can also use "... |patch -s -p1 ". Then
     _only_ the errors will be reported. If you want a log, you can also 
     "... |patch -s -p1 | tee /tmp/HiSax.log". Then you get a logfile in
     addition to the screen output.

Notice: In the meantime there are newer versions of HiSax.

Are there patches to the HiSax driver?

Yes. Karsten <keil@temic-ech.spacenet.de> wrote on 15.10.96:
```
     The patches (until the next version) will be "numbered" with letters
     and be available via FTP.
```
FTP here means ftp.franken.de /pub/isdn4linux/HiSax

What does the remark: "Known Bugs: incoming calls are only delivered, if channel == B-channel (same on teles)" mean?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 14.10.1996:

     1. The above statement is not quite correct:
        if ((channel &1)+1 == B-channel )
     2. I described the bug the other way around: if B channel 1 is
     being used by another ISDN device and i4l dials out, then the
     logical channel 0 from the VST is assigned B channel 2 ---> OK
     The other ISDN device hangs up.  Another call comes in for i4l,
     this time on B channel 1.  Since channel 0 is taken, and there is
     a fixed order B1->chan 0,2,4...  B2->chan 1,3,5... the call is
     not accepted.  (chan 2,3 is for 2 cards, etc.)  This happens only
     seldomly, and will be fixed soon (if I get a brilliant idea).

[As far as we know, this was fixed in HiSax 1.2. Ed.]

My ELSA card has 2 LEDs that light up like a neon sign. What does that mean?

Karsten Keil <keil@temic-ech.spacenet.de> wrote 14.10.1996:

     l1 is down
       => both LEDs blink ca. 1s on 1s off.
     l1 is activated (also though the telephone or whatever)
       => Blink in sequence 0.5 yellow 0.5 green
     In use
       => 1.5 on 0.5 off
          green   HSCX A active
          yellow  HSCX B active
     The constant blinking is caused when the card hangs, as I noticed
     during development.

2.5 ICN driver

Where can I buy the ICN card?

   Thinking Objects Software GmbH
   Obere Heerbergstr. 17
   97078 Würzburg
   Germany
   Tel: +49-931-2877950
   Fax: +49-931-2877951
   email isdn-support@think.de
   WWW http://www.think.de/

Where can I get the newest firmware for my ICN?

Torsten Hentschel <Torsten.Hentschel@DInet.de> wrote on 11.Oct.1996:

     The newest firmware should be available under the URL
       ftp://ftp.think.de/pub/isdn4linux/firmware/

Is it possible to use several ICN cards in one computer?

Yes, but starting with kernel 2.0.0 the configuration scheme has changed: With older kernels, a separate ICN module had to be loaded for each card. For 2 cards it looked something like this:

     /sbin/insmod -m /lib/modules/1.2.13/misc/isdn.o >/etc/isdn.map
     /sbin/insmod -m /lib/modules/1.2.13/misc/icn.o >/etc/icn.map
     /sbin/insmod -m -o icn2 /lib/modules/1.2.13/misc/icn.o >/etc/icn2.map

With kernel 2.0.0 only one driver is necessary. NOTICE: 2.0.0 itself is buggy, better to use 2.0.18 or newer.
Here is an example for one ICN-2B and two ICN-4B:

     /sbin/insmod -m /lib/modules/`uname -r`/misc/isdn.o > /etc/isdn.map
     #
     # ICN-2B, default port and mem (0x320, 0xd0000)
     #
     /sbin/insmod -m /lib/modules/`uname \
       -r`/misc/icn.o icn_id=icn0 > /etc/icn.map
     #
     # ICN-4B inserted at port 0x328
     #
     /sbin/icnctrl add 0x328 icn1 icn2
     #
     # Another ICN-4B at port 0x300
     #
     /sbin/icnctrl add 0x300 icn3 icn4
     #
     # Load firmware 
     #     ICN-2B: 1TR6
     #  1. ICN-4B, both S0 EDSS1
     #  2. ICN-4B, 1. S0: 1TR6, 2. S0: EDSS1
     #
     /sbin/icnctrl -d icn0 \
       load /etc/loadpg.bin /etc/pc_1t_ca.bin
     /sbin/icnctrl -d icn1 \
       load /etc/loadpg.bin /etc/pc_eu_ca.bin /etc/pc_eu_ca.bin
     /sbin/icnctrl -d icn3 \
       load /etc/loadpg.bin /etc/pc_1t_ca.bin /etc/pc_eu_ca.bin

My ICN 4B is recognized only as an ICN 2B. How is the syntax for loading icn.o with insmod for the ICN 4B?

dietmar <dietmar@highway.bertelsmann.de> wrote 08.Oct.1996:

     I use the following script to "start" the card:
       #!/bin/sh
       #
       # load modules
       /sbin/modprobe isdn.o
       /sbin/modprobe icn.o icn_id=icn0 icn_id2=icn2
       #                                ^^^^^^^^^^^^
       #                                Important here is the entry for
       #                                icn_id2. Then the driver recognizes,
       #                                that a 4B should be used.
       #
       # download firmware
       cd /usr/src/isdn4k-utils-1.3.97/icn
       icnctrl load download/loadpg.bin download/pc_1t_ca.bin \
         download/pc_1t_ca.bin 
       /sbin/isdnctrl verbose 2

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE> wrote on 8.Oct.1996:

     modprobe icn icn_id=line0 icn_id2=line1 icnctrl io 0xd0000 0x340
     icnctrl add 0x340 line0 line1
     icnctrl load /sw/linux-i386/isdn4kutils-2.0.0/lib/loadpg.bin   \
                  /sw/linux-i386/isdn4kutils-2.0.0/lib/pc_1t_ca.bin \
                  /sw/linux-i386/isdn4kutils-2.0.0/lib/pc_1t_ca.bin

What is "lanx75i.bin" in the ICN directory?

"lanx75i.bin" is old. Previously, with EDSS1 only HDLC was supported. lanx75i.bin was the first test version of the firmware that also supported X.75. When the firmware was loaded, its version was noted in the kernel syslog. For the current firmware, the following strings should be shown:
```
     For EDSS1:
       DRV1.11EC-Q.931-CAPI-CNS-BETA-15.07.95,BRV2.3
     For 1TR6:
       DRV1.01TC-1TR6-CAPI-CNS-BETA-03.05.95,BRV2.3
```

2.6 Working together with other ISDN devices

What settings does ISPA etc. (DOS, Windows) need to work with the standard settings of isdn4linux?

The following configurations are possible (these also apply to the other drivers from H. Hanewinkel, i.e. CINDI, CANDI, WISPA...) that can be found via link http://www.informatik.uni-bremen.de/~henker/dank;):

     i4l side                             ISPA side
     ====================================================
     isdnctrl l2_prot isdn0 hdlc           \
     isdnctrl l3_prot isdn0 trans           >   -h0
     isdnctrl encap   isdn0 rawip          /
     ----------------------------------------------------
     isdnctrl l2_prot isdn0 hdlc           \
     isdnctrl l3_prot isdn0 trans           >   -h1
     isdnctrl encap   isdn0 uihdlc         /
     ----------------------------------------------------
     isdnctrl l2_prot isdn0 x75i           \
     isdnctrl l3_prot isdn0 trans           >   -l0
     isdnctrl encap   isdn0 rawip          /
     ----------------------------------------------------
     isdnctrl l2_prot isdn0 x75i           \
     isdnctrl l3_prot isdn0 trans           >   -l1
     isdnctrl encap   isdn0 uihdlc         /
     ----------------------------------------------------

The parameter with the least problems is -h0.

What do I have to watch out for to connect to Windows95?

Torsten Krueger <torsten@nrw-online.de> wrote on 5.10.1995, that VJ (i.e. header) compression has to be turned off on both sides. Windows95 is very touchy if this option is rejected by isdn4linux.

Can use only syncPPP with Windows95 to connect to isdn4linux?

Frank-Christian Kruegel <fchk@gigabyte.ohz.north.de> wrote on 13.10.1996:

     Modem network: yes. This might also be possible with CINDI,
     WISPA etc. from Herbert Hahnewinkel (costs ca 80 DM per license, and
     every user needs one), but I didn't spend the money.

A Windows95 user with a Fritz! Card poor transfer rates when connected with isdn4linux - what can one do?

Sven Engelhardt <sven@sik.de> wrote on 13.10.1996:
```
     use AVMPort (Capi modem emulation for Win' 95), important: on
     Win 0.95 "Register on network" should be turned on.
```

Where in Windows95 can I find the settings to get a terminal window when I log in?

Sven Engelhardt <sven@sik.de> wrote on 13.10.1996:

     Control Panels/Software/Diskette CD-ROM Admin/Apptools/Dscript
       - Script administration for modem networks (after installing
       see Start/Programs/Utilities)
     So that the script receives something, with ISDN turn echo. With
     the AVMPort put E1 in the init string.

I'd like to exchange data with a Macintosh (Leonardo card), what do I or the Mac user have to watch out for?

Markus Reicher <a9003436@unet.univie.ac.at>:

     When you call the Mac, he should set the protocol to X.75 or HDLC. 
     When he calls you, he must explicitly set the protocol (e.g. 
     by inserting an "X" for X.75) in the called number - otherwise the Mac 
     might call with the Leonardo protocol.

A Macintosh with a Leonardo card tries to call in , and wants to negotiate chap md5. How can I switch it to CHAP/PAP?

Axel Jindra <jindra@uni-koblenz.de> wrote on 10 Jan 1997:
You can't. He should use LeoPort (always included with the card) and switch the CTB port to the ISDN card. Then with FreePPP 2.5v2 <http://www.rockstar.com> set the Leo as the modem and configure FreePPP as usual. Then PAP/CHAP can be set.
How does isdn4linux work with a Cisco (HDLC) on the other side

On the Cisco router the "keep alive" packets have to be turned off. isdn4linux has to be configured with HDLC, transparent with Cisco encapsulation:
```
     isdnctrl l2_prot <interface> hdlc
     isdnctrl l3_prot <interface> trans
     isdnctrl encap <interface> cisco-h
```
<interface> is the name of the IP interface that has been set up with
```
     isdnctrl addif <interface>
```
(e.g. isdn0).

My Cisco has a Bug - which IOS is recommended?

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE> wrote:

     Since Cisco-IOS 11.0.x (x = 7 is the only one I know about) I've had no
     more problems with Cisco <-> HDLC <-> non-Cisco. That applies for netgw
     as well as i4l and Banzai! on the other side, although in each case the
     special Cisco HDLC options are important.

When I call in to an ASCEND, does it cost a charge unit even if I get a "BUSY"?

Winfried Haug <haug@seicom.net> wrote on 12.10.1996:

     Until yesterday we had problems with AVM+W95 and Mini Port driver
     (PPP with PAP). The Ascend took the call and 3-4 sec later hung up.
     In the Ascend Log is just Call refused, which isn't right, since
     the Ascend did take the call...  With a new firmware on the
     Ascend (4.6C+) instead of 4.6B+p2, the problem seems to be gone.
     Since before we had another RACK (from ITK) that did _not_ behave
     this way with our customers, I'm assuming that is was the Ascend.
     New firmware for the Ascend can be found at

       ftp://ftp.ascend.com/

     or

       ftp://ftp.ascend.de/
 
     although you have to pay very close attention that you are taking the 
     correct image!

Is there a mailing list about Ascend?

There is such a mailing list at the University of Hannover. It's called: ascend-users-de@uni-hannover.de The list is administered with LISTSERV, that means subscriptions go to LISTSERV@uni-hannover.de with the following line in the message body:

       subscribe [my mail alias address] ascend-users-de

or simply:

       subscribe ascend-users-de

Thomas Stinner <Thomas.Stinner@pop-siegen.de> wrote to us in addition:

There is a more widely subscribed mailing list on Ascend. It is in English (so Ascend technicians also read and send messages there). One can subscribe at: majordomo@bungi.com

In the message body:

subscribe ascend-users

How do I switch on Raw IP on the Ascend Max with Radius?

"Framed Protocol" must be set to "EURAW". For the authorization via Caller Id, the "authentication-type = ascend-clid" must be set. Thomas Stinner <Thomas.Stinner@pop-siegen.de> wrote to us on 9 Mar 97:

        It could by, that the Authentication Type works this way, however 
        I use password "Ascend-CLID" to do this.
        An entry in the users file has to look like this:
          69123456 Password="Ascend-CLID"
          User-Name = "Username"
          User-Service = Framed-User
        That means, the Caller ID as username, and "Ascend-CLID" as Password.

How do I switch on "uihdlc" encapsulation on the Max (an Ascend) with Radius ?

"Framed-Protocol" must be set to "EUUI".

What settings does an ELink need to work with isdn4linux?

In the mailing list Daniel Moeller (danny@rsun.lfn.unterland.de) gave the following advice:

     [...] Here I have several clean connections every day to a
     EL310, I poll using ifcico FIDO with it. Here is the config 
     for the Elink:
     ati Elink 310 Version 1.36 OK ati4
     Baudrate: 115k2,N
     SIN unbekannt: Ruf annehmen
     Anschaltung: EDSS1
     SIN ungleich &B: Ruf annehmen
     Betriebsart: X.75
     SIN gesendet: neutral
     Mehrfachrufnummer: 980031
     E1 M1 Q0 V1 X2 &B049 &C1 &D2 &R0 &S1
     \A3 \J0 \N3 \Q3 \V1 %A013 %C1 %F1 FCLASS=000
     S00=000 S01=000 S02=043 S03=013
     S04=010 S05=008 S06=002 S07=040
     S08=003 S09=000 S10=007 S11=000
     S12=050 S13=01010000B S14=10011010B S15=00001110B
     S16=10110011B S17=049 S18=013 S19=003
     S20=000 S21=00000100B S22=000 S23=006
     S24=120 S25=128 S26=016 S27=002
     S28=003 S29=128 S30=000 S31=000
     OK

I can I use Internet with the German T-Online with i4l?

Rainer May <r_may@kahvi.desaster.heide.de> described it as follows:

     (the same works of course with a modem. However, the initializing
     sequence looks different.)
     Step 1: Get diald. I don't know where to find it -  ask archie. 
             (diald is used to set a default route to a physically
             non-existent SLIP or CSLIP connection; when packets are set to
             this pseudo-interface, diald establishes the (C)SLIP connection;
             which packets start the connections and when/how the connection
             is terminated can all be configured.) Then install the binary and
             config files (you can use the sample files as they are, but if
             you want e.g. ping to start a connection, you need to make minor
             changes, the timeouts can also be adjusted as needed -  simply
             try it out).
     Step 2: Use a kernel with integrated SLIP/CSLIP or with SLIP/CSLIP
             modules (which has to be loaded, of course).
     Step 3: Isdn4Linux also has to be installed, of course; the important
              part is the modem emulation (ttyIX),
     Step 4: Start diald, e.g. with the following script (I call it
             /etc/rc.d/rc.diald.t-online):
     /usr/sbin/diald /dev/ttyI2 -m aslip local 192.168.90.9 \
     remote 192.168.90.1 defaultroute dynamic modem crtscts \
     lock speed 38400 connect "chat -v -f /etc/diald/t-online" \
     mtu 1500 dslip-mode local-remote
     (This can also be sensibly written in a _single_ line :-)
     Step 5: Write the script, I call it "etc/diald/t-online".
             Looks something like this:
          TIMEOUT 30
          ABORT "NO CARRIER"
          ABORT ERROR
          ABORT "NO DIALTONE"
          ABORT BUSY
          ABORT "NO ANSWER"
          ABORT "NO MSN/EAZ"
          "" ATZ
          OK AT&B2000&E<MyMSN>&X1
          OK ATD01910
          CONNECT .
          "[?25h" <ZugangsKennung>\c
          "[?25h" ""
          "[?25h" ""
          "[?25h" <passwort>
          "[?25h" *53#\c
          "[?25h" *190144100#\c
          "[?25h" 19\c
          "STATUS OK" LIN
          "" "OK"
        Certain place holders need to be replaced, of course:
       <MyMSN> is the MSN, that you want to explore the world with.
       <Zugangskennung>: The digit monster than usually begins with "000..." 
                         that has been given to you by the Telekom.
       <passwort>:       The password.
     This example script assumes that the default "Anschlußnummer" and
     "Mitbenutzernummer" are used. If this is not the case, you have to
     adjust the two lines before "[?25h" <passwort> accordingly. For example,
     for the Mitbenutzernummer "0003", the line before "[?25h" <passwort>
     should read:
       "[?25h" 0003\c
     (since the entry field is full after "0003", no CR is entered
     afterwards) When diald is running, an interface "sl0" should
     suddenly be available (ask ifconfig), and the default route
     should point to it (route -n will tell you; without "-n", "route"
     will try to resolve the fantasy IP addresses (which are later
     replaced with real addresses) - we don't need it do to
     that). Those who don't work only with numeric addresses, but also
     want to successfully try to "ftp ftp.sunsite.edu", should of
     course enter a name server in /etc/resolv.conf (one from the
     Telekom has the address 94.25.2.129). Then start ftp, telnet,
     netscape, whatever. That's it. By the way, diald will write
     novels in your syslog. You can read the entire login procedure,
     even if it looks somewhat chaotic. If a request doesn't work, use
     "kill" to stop diald (routes will be automatically erased) and
     check the syslog - if there is something like "Zur Zeit keine
     verbindung möglich", then the Telekom's gateway is down.  Or
     perhaps the login is incorrect... watch out, after three
     unsuccessful login attempts, the login will be closed and has to
     be reactivated (either per telephone or directly from BTX
     (e.g. seyon or minicom, dial 01910, slowly go through the login
     screen by hand and follow the instructions).

A further example with dip instead of diald can be found at:
http://www.rosat.mpe-garching.mpg.de/~web/ISDN.html

I've set up an Internet connection over T-Online as described in the groups, but the chat script fails ("Connect script failed").

Gerhard Träger <gerhard@gt-priv.m.eunet.de>: wrote:

     In the mentioned version of chat, there is a small mistake in logf():
     it keeps writing in a 256 byte buffer until a line feed comes in. 
     "T-Offline" sends many more bytes for its login page. Therefore, either
     use chat without -v or enlarge the bugger (best with capacity checking).

2.7 Raw IP

What is Raw IP?

Raw IP does without the use of a protocol such as X.75 or HDLC (for modem emulation, etc.) or PPP. TCP/IP packets are directly exchanged.

What are the advantages and disadvantages of Raw IP?

Raw IP has both advantages and disadvantages.
Advantages :

        * No handshaking 
          => faster connections
        * Authorization by Caller ID
          => fast, safe, no password
        * Fixed IP address
          => a broken connection can be continued by redialing
        * Higher data transfer rates
        * Better stability (smaller driver => almost no bugs)

Disadvantages:

        * No handshaking 
          => Configuration must occur beforehand (IP addresses,...)
          => sensible to use for only for one provider at a time 
        * Authorization only by Caller ID
          => Dialin only possible from one's own number
        * Fixed IP address
          => must be known ahead of time, more IP addresses required,
             no dynamic assignment of addresses possible.

From this summary it should be clear under what conditions it makes sense to use raw IP.

How can I run a script when a raw IP connection is established?

Harald Milz <hm@seneca.muc.de> wrote on 28 Nov 1996:
Make a tail -f of your syslog and attach a script that reads it, e.g. (all on one line!)
```
         tail -f /var/log/messages |
             awk '/isdn0 connected/ { system ("ip-up") }
             /hangup isdn0/    { system ("ip-down") } '
```
or more elegantly in perl.
[isdnlog might also be able to be programmed to do this - Ed.]

2.8 Modem emulation (use with ttyI* devices)

Does modem emulation mean that I can toss out my analog modem?

No, the name "modem emulation" refers only to the way your own computer communicates withe the ISDN driver. It has nothing to do with the way the data is sent by the ISDN driver over the telephone line - that is done digitally! That means that the ISDN driver will not be able to connect to a non-ISDN BBS
The name is justifies, because any Linux software that can send commands to a modem can also via "modem emulation" send commands to the ISDN driver. And that's what we really want.
Which device should I use for calls out or calls in?

Only the ttyI* devices should be used. The cui* devices are created only for reasons of compatibility. Now that there is mgetty, there is not reason to use the cui* devices any longer. If they are used, locking will not work correctly (several programs could simultaneously attempt to use the same device).
How to I switch the modem emulation from X.75 to HDLC?

With the option S14=3; for example "ATS13=3".
How can I poll with Taylor-UUCP using isdn4linux?

As usual, the same as with serial interfaces. Simply use /dev/ttyI* as the device, as the init string for the modem emulation you have to set the correct MSN or EAZ with "AT&E<msn/eaz>".
What speed should I set for the modem emulation?

It doesn't matter. The driver internally always uses the full speed that ISDN offers. This is also given in the connect string.
Is 'init-chat "" ATZ OK AT&E4 OK ATS14=3 OK' correct for 1TR6 (the other side has DSS1)?

In principle, yes, when the EAZ is really 4 (at&e4) and HDLC should be used (ats14=3).
Was does the register S13 exactly mean?

Fritz Elfert <fritz@wuemaus.franken.de> wrote on 1 Dec 1996:
When a user program calls a write to the ttyI device, isdn_tty_write() is called. There the data is copied to a buffer (info->xmit_buf[]), and - if in voice mode - DLE sequences are decoded. Then a counter (info->xmit_count) is updated, that updates the size of the buffer. Through the timer interrupt, the function isdn_tty_modem_xmit() sequentially calls two further functions: isdn_tty_senddown() and isdn_tty_tint(). The job ofisdn_tty_tint() is to pack the data from the buffer into sk_buffs (the packet buffer also used by networking) and also to convert as needed into the various audio formats after aLaw and, also as needed, to create a T.70 header. The resulting packet is put into a send queue (info->xmit_queue).isdn_tty_tint() works through this queue, and passes the packets on to the appropriate low-level driver
Now if Bit 1 in Register 13 is set, the call to isdn_tty_senddown() and isdn_tty_tint() will in addition to the timer interrupt call isdn_tty_write(), that is immediately when the write is called by the user program.

2.9 Async PPP

(The following questions are mostly from the syncPPP FAQ by Michael Hipp.)

pppd, ipppd, async PPP, sync PPP - what are they? Which should I use?

async PPP is a character-based protocol which is usually used over analog serial lines. It is of course possible to route async PPP over ISDN (even though ISDN offers a synchronous connection. You can do this by attaching an ISDN modem to your computer. An ISDN modem has an RS-232 interface to the computer along with an ISDN interface to the telephone company. Assuming that you use PPP on a serial interface, then the asynchronous PPP packets are transmitted over the synchronous ISDN line. You can not use HDLC/syncPPP, otherwise your Linux machine will not accept and process these packets. Instead, you have to edit /etc/inittab:
```
        #
        # inittab       This file describes how the INIT process should set up
        #               the system in a certain run-level.
        [...] 
        # PPPD for asyncPPP over ISDN
        i1:45:respawn:/usr/sbin/pppd -detach silent noipdefault /dev/ttyI0
```
This tells init that the asynchronous PPP should be started directly from this device. Notice that with the configuration, PPP and only PPP is using this line. There are other ways as well; you can start a getty on this tty, set up user that starts pppd, etc. If you want to learn more, you can read the FAQ that comes with the standard pppd.
On the other hand, Sync PPP is a bit-oriented protocol, for which the original pppd cannot be used. Michael Hipp has written an adapted version called ipppd.
ipppd can process PPP packets that arrive as HDLC frames. The PPP driver in isdn4linux sends all IP packets directly to the network layer, while all PPP protocol frames are send to the /dev/ippp* device. Thus ipppd can be viewed as a simple external network protocol program. If you with the help of the /dev/ttyI* devices log in to an external computer and from there start PPP, then you should use the "old" pppd. If the other side immediately begins the send frames, then you've probably reached a syncPPP machine - use the network device from isdn4linux with 'syncPPP encapsulation' and make sure that ippd is running and can contact at least one /dev/ippd*. Make sure you read the directions for isdn4linux on how to configure a network device.
I would like to use asynchronous PPP. Can I use the network interface from isdn4linux?

No, that's not possible. Asynchronous PPP encapsulation is only possible with the standard PPP package (pppd) through the dev/ttyI* devices (see the previous question). The network interface can only be used by ipppd for synchronous PPP encapsulation.
How can I reduce the login time?

See the answer for sync PPP, it also applies to async PPP.
How can I increase my transfer rates with PPP?

You can add more channels with MPPP (see the appropriate section). For everyone for whom that's to expensive and who use async PPP, there's a little trick. With the option "asyncmap 0" you can avoid escaping all control characters (ASCII<32). If the other side goes along with this, you can increase the transfer rate by about 12%.

2.10 Sync PPP

(The following questions are mostly from the syncPPP FAQ by Michael Hipp.)

pppd, ipppd, syncPPP, asyncPPP .. what is they? What should I use?

See this question in the "asnycPPP" section.
How do I compile isdn4linux with syncPPP?

To compile the kernel with syncPPP included in ISDN4Lilnux, you have to answer the appropriate questions in "make config" with "yes". Don't forget to load the module slhc.o before isdn.o, if VJ compression is not compiled into the kernel (e.g. if you have no PPP and no CSLIP in the kernel. [Note that the use of VJ is problematic and does not work reliably - however, the support should still be included in the kernel, since there can otherwise be side effects.]
How does use isdn4linux with syncPPP?

Synchronous PPP is simply another encapsulation for ISDN4Linux. This encapsulation is called "syncppp", therefore for example:
```
     /sbin/isdnctrl encap ippp0 syncppp
```
Here the name of the interface is "ippp0". An interface with this name is always used to keep ipppd happy, since it checks the PPP version through this device. For now, all devices have to have the name ippp*, where "*" is a decimal digit.
How should I name my network interface?

The name of the network interface should always begin with "ippp", not with "syncppp" or "isdn"; otherwise the communication with ipppd will not work correctly.
How do I configure a PPP connection with ipppd?

You have to start ipppd once after the modules are installed. ipppd communicates with the isdn4linux link level devices through /dev/ippp0 to /dev/ippp63. A single ipppd can handle all devices at once. If you want two PPP connections at the same time, you need to bind ipppd to two devices, etc. ipppd has an additional option: "useifip" uses the IP address of the connected network interface (if it is not 0.0.0.0). (Even then, ipppd tries to use the pointopoint address as the remote IP.) BSD compression has to be turned off - this version cannot use it. [Comment: Van Jacobson compression also has to be turned off, in all cases!] In the file etc/rc.isdn.syncppp in the isdn4kernel-util package, you can find an example configuration.
How do I get ipppd to open a PPP connection?

With the command "isdnctrl dial <interface>".
How can I tell if a connection is unsuccessful (busy)?

Andreas Berg <berg@studm.hrz.uni-siegen.de> wrote on 24 Nov 1996:
I simply wait a couple of seconds, then check whether the default route exists, if so, then the connection is there as well.
Where can I find the latest version of ipppd?

It is on Michael Hipp's home page:
http://www.sfs.nphil.uni-tuebingen.de/~hipp/isdn/linux/
How can I use more than one ippp* device?

All ippp* devices in use must be configured separately with "isdnctrl addif" etc. Each ippp* device should be assigned to its own IP address (routing!).
Several ippp* devices can be assigned to a single MSN. Several callers can then simultaneously use this MSN.
I want to talk to remote machines which needs different configurations. The only way I found to do this is to kill the ipppd and start a new one with another config to connect to the second machine.

You must bind a network interface explicitly to an ippp device, where you can connect a (for this interface) individually configured ipppd. With the (unfortunately poorly documented) command
"isdnctrl pppbind <interface> <Number>"
you can link the interface <interface> to the device ippp<Nummer>. You can release the link with "pppunbind".
How does the (little-documented) "pppbind" command in isdnctrl work?

You have to first know how ipppd gets its data. All data that come in over the ISDN line is received by the network devices (these are set up with isdnctrl). Then the data given to one of the /dev/ippd* devices - to one where a ipppd daemon is waiting for data.
To the network interfaces, all ipppd's appear to be able to handle the just-received data - therefore it is normally impossible to predict which ipppd will receive data from which network interface.
In practice, you usually install several ipppd's with differing configurations. Each of these should receive data exclusively from a certain network interface (that has also be specially configured). The "pppdbind" command serves just this purpose. With:
```
        "isdnctrl pppbind <interface> <number>"
```
attaches the interface <interface> to the device /dev/ippp<number>.
Example: To attach the interface "ippp5" to /dev/ippp2, the following configuration should be used:
```
        "isdnctrl pppbind ippp5 2"
```
Similarly, the command "pppunbind" will undo this attachment.
I want to use dynamic IP address assignment. How must I configure the network device?

At least you must have a route, which forwards a packet to the ippp network interface to trigger dialing. A default route to the ippp interface will work. Now you must choose a dummy IP address for your interface. If for some reason you can't set the default route to the ippp interface, you may take any address of the subnet from which you expect your dynamic IP number and set a 'network route' for this subnet to the ippp interface. To allow overriding of the dummy address you must call the ipppd with the 'ipcp-accept-local' option. You must know how the ipppd gets the addresses it has to configure. If you don't give any option, the ipppd tries to negotiate the local host address! With the option 'noipdefault' it requests an address from the remote machine. With 'useifip' it gets the addresses from the net interface. You also can set the addresses in the option line with the <a.b.c.d:e.f.g.h> option. Note: the IP address of the remote machine must be configured locally, or the remote machine must send it in an IPCP request. If your side doesn't know the IP address after negotiation, it closes the connection! You must allow overriding of addresses with the 'ipcp-accept-*' options, if you have set your own or the remote address explicitly. Try these options, e.g.:
```
    /sbin/ipppd :$REMOTE noipdefault /dev/ippp0
```
where REMOTE must be the address of the remote machine (the machine giving your address to you)
According to the manpage, ipppd offers the option "dns-addr". But my ipppd refuses to take this option!

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 31 Dec 1996:
In the Makefile for ipppd you have to activate the option "USE_MS_DNS"!
How can I do IPX over ipppd?

Michael Hipp <Michael.Hipp@student.uni-tuebingen.de> wrote on 4 Feb 1997:
So... this question has come up a lot recently. I recommend in any case ipppd 2.2.6g (ftp.gwdg.de pub/linux/isdn/ippp/). Then in the Makefile comment out 'IPX_CHANGE = 1' ...
But that's not yet enough. When calling ipppd, you have to add "+ipx", otherwise IPX (in ipppd) will not be activated. Of course, you also have to use the "correct" IPX options... I don't know what they are for each individual case. I've never done IPX. ;) If you then get several IPXCP debug messages in the log and nothing works, I'd be interested in this log (unless you can analyze the problem yourself). Success stories are also welcome, of course (but with untested software, this is highly improbable) ;)
How can I reduce login delay?

You can write out a login session with ("Debug-Log"), and see which options the other computer is refusing. Next time, configure ipppd without these unused options. A further side effect is that such unused options increase the redundance (e.g. when the other computer has bugs and refuses the options incorrectly). To create a log file, see "How to I create a log for ipppd".
Another tip came from G.Richter <richter@ecos.de> on 12 Dec 1996:
The negotiation phase with a CISCO, as well as with an AVM MPR, was drastically accelerated by the option
```
        lcp-restart 1
```
The ipppd seems to send the first LCP packet before it can reach the other side, and then waits 3 seconds before trying again, but with this option it waits only 1 second. For me the time to establish the connection sank from 5 to 2 seconds.
How can I increase my PPP data transfer rates?

You can establish more channels with MPPP (see the MPPP section). For everyone for whom this is too expensive, and who use asyncPPP there is another little trick. With the option "asyncmap 0", you can chose to not "escape" control characters (ASCII<32) (the default is to escape these characters). If the other side goes along, the transfer rate will be about 12% faster.

2.11 ISDN4Linux in a network

I've successfully used the Internet with my Linux system using isdn4linux. Now I'd like to have another computer on my Ethernet profit from the Internet as well. But how?

Thomas Pfeiffer <pfeiffer@pds.de> wrote on 5 Nov 1996:
There are several choices, depending on what all you would like to do on the Internet from your LAN. Basically, there are 3 possibilities:

        1. Your LAN is an official Class C net with IP addresses valid on 
           the Internet.
             This case is the easiest of configure. You give each network
             card on your network one of these addresses and set a 
             default route on the ISDN card that goes to your    
             provider.
        2. You'd only like to do http in Internet from your LAN.
             In this case you can make up IP addresses for your LAN;
             the only official IP address is that for your ISDN card.
             Then install a proxy server on your Linux router, and
             enter it in all of your browsers. In this case you do
             not need a default route.
        3. From your LAN you only want to log in to your Linux ISDN
           router and FROM THERE do your work on the Internet.
             This is even simpler, then you don't even need a proxy 
             server.

Eike Stepper <isdn@esc-net.de> added on 6 Nov 1996:

        There is a fourth possibility I'd like to add, although I've
        never tried it out (since I prefer the 1st choice and have a
        a Class C Subnet, hehe ;), but I have a friend who after
        some playing with the Linux kernel has actually gotten IP
        masquerading to work.

        It works somewhat like a proxy (when looking at the effect of 
        hiding the IP). It doesn't offer any caching, of course, but 
        masks to the outside all internal IPs with that of the ISDN
        interface. Don't ask me how the routing functions, but it 
        works...

        If I'm not completely mistaken, my friend does this with a
        dynamically assigned IP ?!

How does this fourth possibility work, Linux + Masquerading?

Rainer May <r_may@khavi.desaster.heide.de> has put together a good set of instructions (see the next question).

The following instructions were assembled by Rainer May <r_may@khavi.desaster.heide.de>.
I have a local area network, (LAN) with computers based on several platforms - Win95, Win311, NT, Amiga (AmiTCP) and Macintosh (MacTCP) - all connected to the outside world through a Linux router. The Linux machine has an ISDN card. My ISP provides me with a dynamic IP address each time I log in. I want all the computers to reach the INTERNET not just the Linux box. How can I do this?

Most work has to be done on the Linux box. First you need a kernel with IP forwarding and masquerding enabled. You can get on by answering the following questions when doing "make config" with YES.
```
     Prompt for development and/or incomplete code/drivers  Y
     Enable loadable module support                         Y
     Networking support                                     Y
     Network firewalls                                      Y
     TCP/IP networking                                      Y
     IP: forwarding/gatewaying                              Y
     IP: firewalling                                        Y
     IP: masquerading                                       Y
     PPP (point-to-point) support (if you  PPP to the  ISP) Y
     SLIP (serial line) support                             Y
     Ethernet (10 or 100Mbit) (or Arcnet or ...)            Y
     ISDN support [1]                                       M
     Support synchronous PPP (if you're using ipppd)        Y
     HiSax SiemensChipSet driver support                    M
       (Then select the HiSax support)
     (You can also choose to make a kernel with build in ISDN support
     instead of modules)
```
Then do a "make dep", "make zImage", "make modules" and "make modules_install" to build the kernel. The installation of ISDN and PPP is explained somewhere else in this FAQ. We now continue with the following assumptions:
* The ISDN system is operational; you can build a connection to your ISP.
* The LAN is operational (i.e. Ethernet or Arcnet) and IP addresses have been assigned (i.e. 192.168.xx.xx). The Linux box can be reached by the other computers (i.e. by ping).
Now we need to accomplish two things:
* A computer in the LAN with a "non-local" IP address will request the Linux router to establish a connection to the provider
* The Linux router itself will connect the computers in the LAN to the provider. It will also "hide" the computers in the LAN from the ISP, and all the IP packets will appear to come from or go to the router. While in fact the are coming from the computers in the LAN.

We'll start with the second one: This hiding doesn't mean we're trying to cheat our provider. (Although it is possible to provide "clients" with a cheap connection to the Internet). It is required technically. Only the IP address of the Linux box is known to the provider. So the Linux box must "mask" all the packet with it's own IP address and keep track of which computer in the LAN sent which packet so the it can return the incoming packets to the correct computer in the LAN. Luckily this function is built in kernels>=2.0.0 and is called "IP-Masquerading". Here's how it works:

A computer on the LAN sends a packet that contains (next to the IP address and target port of the receiver) it's own sender address (in IP form) and an answering port. The masquerading Linux router will replace this address with it's own and the answering port with a free one. Under this free port the sender address is stored. Now when a packet comes in from the Internet the receiver address and port gets overwritten with the return address and port and the packet is send to the correct computer in the LAN. Packet for packet. This only works if the application sends along a return address, telnet, http, (irc, tcp differently) all do this (ping doesn't work).

To get TCP and IRC to work while masquerading 2 modules need to be loaded:
```
     /sbin/modprobe ip_masq_ftp
     /sbin/modprobe ip_masq_irc
```
Then the forwarding rules in the kernel add forced to masquerade:
```
     /sbin/ipfwadm -F -a m -P all -S 192.168.123.0/24 -D 0.0.0.0/0 -b
```
The ipfwadm program is available via anonymous FTP at
ftp://ftp.xos.nl/pub/linux/ipfwadm/ipfwadm-2.3.0.tar.gz
In this example the LAN addresses 192.168.123.0 to 192.168.123.254 are used. To keep things simple we make the Linux router 192.168.123.1
The above line masquerades all the packets coming from 192.168.123.x to the outside world. This has a disadvantage: all the packets inside the LAN also get masqueraded. You can prevent this by adding more rules (man ipfwadm is recommended reading if you want to do this).

Hint from Ralf Rudolph <ralf@artifex.de>:
```
    The way I see it, that doesn't matter, the computers in the LAN will
    continue to communicate over the fake IP addresses. You can test this by
    turning off your Linux box (shutdown). Nothing will happen. This is because
    masquerading is a forwarding rule in the firewall and will only be used 
    when forwarding (literally "passing on"). On the LAN nothing is forwarded 
    so nothing is masqueraded, unless you have multiple Ethernet cards in one
    computer then you need to enter some extra firewall rules.
```
Answer: This is actually not entirely true; although it does no harm. We have accomplished "hiding" the LAN from the provider. We now want the Linux box to automatically connect to the outside world whenever a computer in the LAN requests it. All the computers within must address their packets for the outside world to the Linux box, which will take it from there. This is very easy. Most TCP protocols (for Windows, Mac) all have the option of specifying a "default gateway" or "gateway". You must specify the local address of the router. You cannot enter the IP address which you receive when you connect to your provider because you don't know which address your going to get, and also it's different every time you log in.
The last step is getting the ISDN system to do "Dial on Demand". This is can be done in two ways.
* Use synchronous PPP, in other words "ipppd". The only thing you have to do is to make sure that the default route point to the device (ippp*) you made with isdnctrl. Warning: the kernel remove this route when the connection is broken. You have to reestablish the default route after the line goes down. You can do this (for example) in the file /etc/ppp/ip-down. The risk of this method is that applications running on the LAN will make the Linux box build a connection for each resolve request, keepalive packet or ARP broadcast they send (your phone company will be very grateful).
It can happen that requests by the LAN can take a long time. I don't know whether the kernel or ipppd can't handle the first outgoing packets, but it's always a good idea to push the red button in Netscape for example and then reload the first page you're accessing right after starting up Netscape.
The configuration of ipppd is explained in detail elsewhere:
http://www.lrz-muenchen.de/~ui161ab/www/isdn/
* Use asynchronous PPP or SLIP/CSLIP for your connection. For this you can use a program called "diald" [4]. This has several advantages, it's highly configurable; you can for instance specify that there are to be no connections made between 9 and 12 am or that name server request don't trigger the ISDN device. For those of you that don't want to bother with a lot of configuration options that's fine; the default configuration can be used without danger for life or money (German expression).
Now,
if the masquerading rules are set,
if the PC in the LAN all know that the Linux box is the gateway,
if "ping abc.edu" typed in on the Linux console builds up a connection to the Internet provider
then also all other machines in the LAN should be able to access the Internet.
How can I allow the users in my local network to use the ISDN card(s) in my Linux PC?

Rainer May <r_may@khavi.desaster.heide.de> wrote on 10 Dec 1996:
Um ... "modemd" on the Linux side, along with appropriate software e.g. for W95 (emulates a comport over a telnet connection) makes that rather nice....
Where can I find "modemd", and for which platforms are there "clients"?

Rainer May <r_may@khavi.desaster.heide.de> wrote on 10 Dec 1996:
In theory (and in practice too) this can be done by any comfortable telnet client. There should be some uucicos for this as well (under DOS fxuucico together with fxwtcp, for example).
If you generally want to offer all applications a kind of "remote COM port", then there is COMT for Windows (95), "telser.device" for Amigas. There is supposed to be something like this for the Mac as well (it's system architecture is very inviting for this), but I don't know any names.
modemd (which is really just a one-liner in PERL, if I remember correctly) works here with COMt and telser.sevice with no problems.
Where can I find COMt?

Oliver Hahn <oliver@bbtt.de> wrote on 15 Dec 1996:
Try a Simtel mirror (e.g. ftp.funet.fi) in the directory pub/simtelnet/win3/inet. The thing is called comt200.zip. ftp://ftp.funet.fi/pub/simtelnet/win3/inet/comt200.zip

How exactly does this "PERL one-liner" "modemd" look?

Marc Neitzner <marc@zeus.han.de> wrote on 15 Dec 1996:

        #!/usr/bin/perl
        select((select(STDOUT), $| = 1)[$[]);
        select((select(STDIN), $| = 1)[$[]);
        exec "cu","-E","''", "-l", "$ARGV[0]";
       die "$0: Cannot exec cu: $!\n";

And then it has to be started in inetd:

        modem           20006/tcp       modemd  # Modem service via TCP
        isdn            20007/tcp       modemd  # ISDN  service via TCP

Disadvantage: comt-2.0 is only "visible" to 16-bit applications. The use under win95 and Windows NT therefore is restricted to 16-bit stuff.

2.12 Isdnlog

isdnlog doesn't always show the High Layer Compatibility (Speech, Video,...) as I'd like it to.

Gernot Zander <hifi@scorpio.in-berlin.de> posted a patch on 6.10.1996 to the mailing list that adjusts isdnlog
Can I see the service type from an incoming call in the output from isdnrep?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Dec 1996:
Indirectly in isdnrep, yes -- as soon as you enter an alias for the decoded service types in your "isdnlog.conf" ...

Why doesn't isdnlog record the number dialed by my other ISDN devices, since it records the charges?

Because the ISDN card, like all ISDN device, has separate lines for sending and receiving (RX and TX lines). Isdnlog has to read data from the receiving line to learn the number dialed. This isn't possible, at least for the Teles cards, as Karsten Keil <keil@temic-ech.spacenet.de> wrote on 12 Feb 1997:

       This is the case for all cards with 1 Siemens ISAX; it has (and needs)
       only 1 sender and 1 receiver.
       Theoretically, it's possible to read the entire D channel with just one
       receiver (even with the ISAC); the D bits from the RX line are copied 
       (somewhat delayed) to the TX line, over which the access control 
       (collision recognition) of the SO bus takes place.
       Unfortunately with the ISAC it's not possible to read the echo bits 
       in TA mode from a register.

See the next questions for a possible solution.

How can I get isdnlog to also show the telephone numbers for other ISDN devices?

There are two possibilities. First, the German Telekom offers the service COLP (Connected Line Identification Presentation, ca. DM 10 per month per basic line) that returns all data sent. This can then be read by isdnlog (>=2.52) from the TX line
Alternatively, the next version of isdnlog (currently 2.52) will offer the possibility to work with a second "re-poled" Teles card, i.e. the RX line is connected to the TX connection of the card. The RX line of the card should not be connected to any line! Because of this setup, the Teles card cannot be used for anything else. The whole thing looks something like this:
```
 B  3 -- RX+ 2a ---------------\
 U  4 -- TX+ 1a -- open         ------------
 S  5 -- TX- 1b -- open         ------------  card
    6 -- RX- 2b ---------------/ 
```
A third (theoretical) possibility exists for those who have their own PBX to which the other devices are connected. If the PBX can protocol all outgoing calls, this can be read (ustally over a serial port).
There is a reason why isdnlog has not support this until now. To evaluate this data, isdnlog has to be able to access the date immediately after the RELEASE COMPLETE, before any new data is sent on the D channel. The PBXs tested up to now have all been too slow (in particular the widely used ISTEC). The only possibility is to combine the data afterwards. But then there are problems with synchronizing the different times. Whoever want to attempt to do this is welcomme (I'll make the logs from my Ackermann Euracom available - Matthias Heßler <hessler@wi-inf.uni-essen.de>).
Does isdnlog also calculate the new pricing plans of the German Telecom (City Weekend, City Plus)?

Since the switching stations don't get this information, the charge units are not sent correctly. But the next version of isdnlog (<2.52) will be able to do this.
How can I get isdnlog to calculate the charges for the Dutch telephone company?

You need to set "COPTS=--DISDN_NL" in the isdnlog Makefile and recompile.
How can I get isdnlog to calculate the charges for the Swiss telephone company?

You need to set "COPTS=--DISDN_CH" in the isdnlog Makefile and recompile.
How can I display the data transfer rates graphically?

You can use "xisdnload". Clemens Perz <listperz@gwsnet.ttt.de> on 6 Feb 1997 knew of another possibility:
On Sunsite I found a little tool for the console called netload, and apapted it for the ISDN interfaces. With it you can quite easily see the current traffic on the line. It can be found at:
!link ftp://ftp.region.trier.de/pub/unix/linux/sources/network/isdn/netload-0.92.isdn.tar.gz;
Simply start with netload isdnxx

2.13 Isdnbutton

What script should I use to bring down isdnbutton?

Markus Gutschke <gutschk@uni-muenster.de> (the author) wrote on 21 Dec 1996:
Here I use something like:

        #!/bin/bash
        #ISDNBUTTON: Disconnect ISDN
        /sbin/isdnctrl list isdn0 | grep Outgoing | grep -q 0251XYZ &&
             /sbin/isdnctrl delphone isdn0 out 0251XYZ
        /sbin/isdnctrl hangup isdn0
        exit 0

[At the line ending with "&&", the next line must be continued!]
and

        #!/bin/bash
        #ISDNBUTTON: Connect ISDN
        /sbin/isdnctrl list isdn0 | grep Outgoing | grep -q 0251925020 ||
             /sbin/isdnctrl addphone isdn0 out 0251925020
        exit 0

[At the line ending with "||", the next line must be continued!]

What do the different states of isdnbutton mean (green, yellow, red)?

Markus Gutschke <gutschk@uni-muenster.de> wrote on 21 Dec 1996:
"isdnbutton" checks the following conditions:

        GREEN - at least one ISDN connection is active. Unfortunately 
                I'm unable to check how the connection was activated.
                It doesn't have to be a network connection, and can 
                also be an incoming connection (at least for me, it would
                be useful to distinguish these).
        YELLOW- no active ISDN connection was found, but at least one
                ISDN interface has an outgoing telephone number for
                demand dialing. There is therefore the "danger" that
                a connection will occur automatically.
        RED   - Neither of the above is true. This usually means that
                a) the kernel doesn't recognize ISDN, or the ISDN
                   subsystem is not active, or
                b) the outgoing ISDN connections are deactivated.

2.14 Audio

(Most of the answers you will find here are taken from the vbox manual by Matthias Hessler <hessler@wi-inf.uni-essen.de> and Bernhard Hailer <dl4mhk@lrz.uni-muenchen.de>; you can get the manual at:
http://www.lrz-muenchen.de/~ui161ab/www/isdn/
- click on "Audio!" (still in German we're afraid - sorry...)

What is the format of the audio messages (.msg) vbox plays when it answers a call?

You can get the format from the messages with rmdgetheader. The samples messages in the packages are recorded using format 4 (the latest Zyxel-Compression)
How can I record my own messages for vboxgetty?

First call yourself on the number you configured vboxgetty to answer and leave a message. Then rename the message to *.msg (standard.msg for the main answering message) and copy it to the directory where all the messages are kept (usually /var/spool/vbox/user/messages where user is the user for which vboxgetty is configured). You can also record a message using a microphone and the soundcard.
How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:
```
   cat xxx > /dev/audio
```
where xxx is the message-file.
If vboxgetty has recorded a message in a format which can not be played using "cat xxx>/dev/audio" how can I still hear the message?

Siehe dazu die gleiche Frage im Abschnitt "Audio" im Kapitel "Troubleshooting".
How can I convert audio messages which where recorded by vbox to other formats (i.e. from uLaw to WAV)?

The standard tool for converting all sound formats is SOX. SOX is available as source code for both UNIX and DOS. You can get it at:
http://www.powerweb.de/mpeg/util/msdos/sox10c.zip
(including sources that compile under Linux).
How can I format WAV for uLaw (for my vbox announcement message)?

We receive the following tip form Christian Stueble <stueble@ls6.informatik.uni-dortmund.de> on 15 Jan 1997:
For me, the following (somewhat indirect) method works:
```
       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg
```
It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

A Banzai! might also help. As hardware any PC with (e.g.) Teles cards would work, the software costs around 800-1000 DM. Axgetty to answer and leave a message. Then rename the message to *.msg (standard.msg for the main answering message) and copy it to the directory where all the messages are kept (usually /var/spool/vbox/user/messages where user is the user for which vboxgetty is configured). You can also record a message using a microphone and the soundcard.

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

If vboxgetty has recorded a message in a format which can not be played using "cat xxx>/dev/audio" how can I still hear the message?

Siehe dazu die gleiche Frage im Abschnitt "Audio" im Kapitel "Troubleshooting".

How can I convert audio messages which where recorded by vbox to other formats (i.e. from uLaw to WAV)?

The standard tool for converting all sound formats is SOX. SOX is available as source code for both UNIX and DOS. You can get it at:
http://www.powerweb.de/mpeg/util/msdos/sox10c.zip
(including sources that compile under Linux).

How can I format WAV for uLaw (for my vbox announcement message)?

We receive the following tip form Christian Stueble <stueble@ls6.informatik.uni-dortmund.de> on 15 Jan 1997:
For me, the following (somewhat indirect) method works:

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and then in the file /usr/local/etc/mgetty+sendfax/login.config, the line
```
#/AutoPPP/ -    ppp     /usr/sbin/pppd auth -chap +pap login kdebug 7 debug
```
should be uncommented and edited.
How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?

G. Richter <richter@ecos.de> wrote on 17 Dec 1996:
In /etc/ppp/pap-secrets, each user must have the following line, if you want to allow in only certain users:
```
        <login-name> * ""
```
or to allow all users simply:
```
        * * ""
```
[The latter can also be achieved when the file pap-secrets does not exist - Ed.]
In either case, ipppd should be started with the options "login" and "auth".
How can I allow several people to call in to me at once?

You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. See also the question "How can I use more than one ippp* device?"
Can I use just one MSN to serve customers both with a getty (modem emulation and with the network?

Gernot Zander <hifi@scorpio.in-berlin.de> wrote on 7 Nov 1996:
Yes. On the one hand, the _customer's_ MSN is enough if the network interface is set to secure on, and customers who want mgetty won't be listed there.
On the other hand, you can get mgetty to recognize a ppp attempt and to then start (i)pppd (although I'm not sure how that would work with ISDN, it works for modems).
Otherwise you can try to teach isdn4linux the HLCs, but then you also have to get the customer to have the correct settings. But the first suggestion will be enough, as long as you don't have any customers who have one MSN but want sometimes this and other times something else.
Can I get the advantages of a multiple-PBX line (one MSN for all ISDN ports) with a multiple-device line [German Telekom]?

Karsten Keil <keil@temic-ech.spacenet.de> wrote on 7 Nov 1996:
According to various articles in the newsgroups, you can get this for multiple-device lines as well, although most of the Tele-Comics don't know about it and it doesn't work in all switching areas.
[This is called a bundled line - Ed.]
When a Fritz! card calls with X.75, Linux crashes. What can I do?

Karsten Keil <isdn4@temic-ech.spacenet.de> has written a new driver (the "HiSax driver"). It includes a bug fix for this. Also see the questions General HiSax and the section HiSax driver in this FAQ.
An AVM (A1 or B1) cannot call in to me with X.75, either under Win95 or under OS/2?

This is a known problem, see the last question. This has now been solved in the HiSax driver, and Karsten Keil <keil@temic-ech.spacenet.de> has posted a patch for the Teles driver as well.
How can enable a Fritz! card to call in to me?

As long as the patch form Karsten Keil <isdn4@temic-ech.spacenet.de> is not applied: only with HDLC - if the card tries to call in with X.75 isdn4linux likes to hang. Therefore you should set up a separate MSN for Fritz! cards with HDLC. The HiSax driver also has the same problem. Note from Roland Rosenfeld <roland@spinnaker.rhein.de>: If you've used up your three MSNs, you can play tricks with the service recognition, e.g.
```
     MSN     Analog                          Digital
     ===     ======                          =======
     1       Voice + ISDN answering machine  HDLC, PPP
     2       Voice (Mother)                  Net interface
     3       Modem/Fax                       X.75
```
If you want, you can install another answering machine on MSN 2 that plays a totally different message...

Which ISDN routers are there that are OS-independent?

Sakari Aaltonen <sakari@picea.hut.fi>:

     There seems to be a lot of routers with 1 BRI, those that have more 
     are expensive (Cisco 4000 with four connection about DM 15000.--,
     Ascend Pipeline 400: ?).

Jürgen Goeritz <juergen@bart.simpson.inka.de>:

     ISDN routers with 4xBRI are less expensive from a German  
     manufacturer - see http://www.conware.de/

Jochen Wiedmann <Jochen.Wiedmann@Neckar-Alb.DE>:

How can I play audio messages locally using /dev/audio?

This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using:

   cat xxx > /dev/audio

where xxx is the message-file.

       sox <file>.wav -r 8000 <file>.ul rate
       rmdcatheader -u <file.ul> > <file>.msg
       cat <file>.ul >> <file>.msg

It could be that you have to give different parameters to sox. As a first test you can try <file>.msg > /dev/audio, you should be able to hear something.

2.15 Diald

How can I combine i4l with diald?

Wim Bonis <bonis@kiss.de> wrote:
The patches for diald can be found at:
ftp://ftp.kiss.de/pub/linux/isdn4linux/diald-0.13-device-patch
They work with diald-0.14. When a newer diald comes out, I'll adjust the patches accordingly...

Are there any example scripts for diald?

Yes, by Rainer May <r_may@khavi.desaster.heide.de>:

    At boot "diald" is configured:
     # /etc/rc.d/rc.diald
       /usr/sbin/diald /dev/ttyI4 -m ppp \
       local 192.168.90.9 remote 192.168.90.1 \
       defaultroute dynamic modem crtscts lock connect "chat -v -f \
       
    In /etc/ppp/chat.provider the following entry is made:
    TIMEOUT 240 "" AT&E1234 OK ATD047110815 ogin: Puser sword: topsecret
    (phone number, name and password are fictional)

2.16 Chargeint

How can I use the "chargeint" patch, so i4l will hang up before the next charge unit begins?

Sascha Ottolski <sascha@alzhimer.isdn.cs.tu-berlin.de> wrote:

     I use chargeint, it works great; for me charge units come during the
     connections, but I think that can be adjusted by hand. The two patches in
     isdnlog-2.50/contrib/chargeint are for the kernel sources and for 
     isdn4k-utils-2.0; then compile isdn with the -Dchargeint flag (see
     Makefile). The kernel and isdnctrl of course also have to be recompiled.
     Then start isdnlog with the -hx option, where x is the number of seconds
     left until the next charge unit. Then chargeint will hang up. In the
     start script for ISDN, define a huptimeout as usual to activate the
     chargeint:
     /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     if needed /sbin/isdnctrl chargeint ippp0

Olav Brinkmann <olav@max.north.de> wrote:

     The chargeint always hangs up two seconds before the end of the charge
     unit. isdnlog, if compiled with -Dchargeint, sets the length of the
     charge unit (i.e. Charge Interval) according to the time of day and the
     date. An additional parameter for "-h" will reduce this length of time by
     the given value. This additional parameter should not be used with
     chargeint, otherwise chargeint will end the connection too early. This
     error increases with the number of charge units. Therefore: "-h0" to
     avoid this problem. 
       > /sbin/isdnctrl huptimeout ippp0 80  # in sec;
     In this example is can be much short; I use 5 seconds. Then I can use the
     last charge unit up the last 7 seconds (huptimeout + 2 seconds
     "chargeint reserve").
       > /sbin/isdnctrl chargeint ippp0
     Not needed; taken care of with by isdnlog with "-h".

With which drivers can I use the chargeint patch?

You can use the Teles or the HiSax driver. Of course, isdnlog must be running correctly (isdnlog 2.50 has to be patched to 2.51 to run with the HiSax driver).
When does it not make sense to use the chargeint patch?

There are problems when the IP is assigned dynamically. Then a broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established.
How does the chargeint patch work?

With the isdnctrl parameter "chargeset" you can set the length of a charge unit, so that it can hang up at the correct time. However, since the length of a charge unit depends on the time of day, day of week, holiday, etc., it makes no sense to use a set value. Here's where isdnlog comes in. It notices when a connection is established and calculates the length of a charge unit depending on the time of day, day of week, holiday. This is then given to isdnctrl, so it can hang up at the right time. isdnlog "tunes" isdnctrl at each connection, and also during a connection (when isdnlog is run with the "-w x" parameter). isdnlog allows isdnctrl exactly 2 seconds before the next charge unit to hang up, as long as the time entered with "huptimeout" has elapsed with no data being transferred. The transmission of a charge unit impulse is not necessary, since the times are calculated closely enough. The charge unit impulse is sent a varying intervals, so it cannot be relied upon

How do I configure the chargeint patch?

Andreas Kool <akool@Kool.f.EUnet.de> wrote on 3 Jan 1997:

        1. Apply the patch "isdnlog-2.50/contrib/chargeint/patch-chargeint-2.04"
           to the kernel, rebuild the kernel and reboot.
        2. Patch isdn4k-utils-2.0 with
           "isdnlog-2.50/contrib/chargeint/patch-chargeint-kutils",
           make clean; make install
        3. In etc/isdnlog/isdnlog.conf" enter the appropriate interface 
           in column 4 for those partners you wish to add, and double check
           that the zone entries are correct.
        4. In the "Makefile" for isdnlog, insert "-DCHARGEINT" for "COPTS",
           make clean; make install
        5. start isdnlog the additional option "-h0", done!

Where can I find more detailed instructions for the chargeint patch?

Georg v. Zezschwitz <gvz@hamburg.pop.de> wrote on 29 Nov 1996:
I've finally written some quick and dirty docs for the chargeint patch: - For whom is it appropriate? - How do I apply it? - What does it do? - How can it be best configured? Default URL: http://www.provi.de/~gvz/chargeint.html
How can I be sure that the chargeint patch is using the correct time?

It's best to synchronize the clock in your own computer with that of the switching station with "isdnlog -t2". For setting the clock, see the "Miscellaneous" section, the question: "How can I set the clock of my computer with ISDN?"

2.17 Dial-In

How can I enable others to login via ISDN?

The same way as via a normal serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices with modem emulation (/dev/ttyI*). The entry in /etc/inittab looks like this:
```
     #
     # ISDN Lines
     #
     I0:56:respawn:/usr/local/sbin/mgetty ttyI0
     I1:56:respawn:/usr/local/sbin/mgetty ttyI1
```
Then the init string needs to be entered in the mgetty.config, since mgetty needs to know which MSN or EAZ to "listen" to. Here is an example for /dev/ttyI0
```
     port ttyI0
     modem-type data
     speed 38400
     init-chat "" ATZ OK AT&E0 OK AT&B512 OK
```
The example sets the EAZ (with 1TR6-ISDN) to 0. For Euro ISDN, the MSN (without area code) would be given instead of the 0 in "AT&E0". For X.75 the block size is set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in /etc/inittab (here printed on two lines!):
```
     i0:45:respawn:/sbin/mgetty -D -m '"" ATZ OK AT&E0 OK AT&B512 OK'
       -s 38400 ttyI0
```
The most elegant way is to use iprofd. This daemon takes advantage of the AT&W0 command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. "iprofd /etc/i4lprofile" Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT commander by hand. When finished, enter the command AT&W0, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with ATZ
Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?

No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3).
Is it possible with mgetty to automatically start pppd when LCP frames are received?

Yes, it is. You have to compile mgetty with "-DAUTO_PPP" and th

FAQ for isdn4linux - Version 1.3.3 (translation 3-Oct-97)

1 General information about isdn4linux

2 Configuration

2.1 General

2.2 MSN

2.3 Teles driver

2.4 HiSax driver

2.5 ICN driver

2.6 Working together with other ISDN devices

2.7 Raw IP

2.8 Modem emulation (use with ttyI* devices)

2.9 Async PPP

2.10 Sync PPP

2.11 ISDN4Linux in a network

2.12 Isdnlog

2.13 Isdnbutton

2.14 Audio

2.15 Diald

2.16 Chargeint

2.17 Dial-In

2.18 Leased lines

2.19 SPV

2.20 Channel bundling

3 Troubleshooting

3.1 General

3.2 Teles driver

3.3 HiSax driver

3.4 ICN driver

3.5 Working together with other ISDN devices

3.6 Raw IP

3.7 Modem emulation (use with ttyI* devices)

3.8 Async PPP

3.9 Sync PPP

3.10 ISDN in a network

3.11 Isdnlog

3.12 Audio

3.13 Dialout on demand

3.14 Chargeint

3.15 Dialin

3.16 Callback

3.17 MPPP

4 National Peculiarities

4.1 Germany (1TR6)

4.2 Italy

4.3 The Netherlands

4.4 Austria

4.5 Switzerland

4.6 Portugal

4.7 North America

5 Miscellaneous

FAQ for isdn4linux - Version 1.3.3 (translation 3-Oct-97)

1 General information about isdn4linux

2 Configuration

2.1 General

2.2 MSN

2.3 Teles driver

2.4 HiSax driver

2.5 ICN driver

2.6 Working together with other ISDN devices

2.7 Raw IP

2.8 Modem emulation (use with ttyI* devices)

2.9 Async PPP

2.10 Sync PPP

2.11 ISDN4Linux in a network

2.12 Isdnlog

2.13 Isdnbutton

2.14 Audio

2.15 Diald

2.16 Chargeint

2.17 Dial-In

2.15 Diald

2.16 Chargeint

2.17 Dial-In

2.15 Diald

2.16 Chargeint

2.17 Dial-In

2.15 Diald

2.16 Chargeint

2.17 Dial-In

2.15 Diald

FAQ for isdn4linux - Version 1.3.3
(translation 3-Oct-97)

FAQ for isdn4linux - Version 1.3.3
(translation 3-Oct-97)