Some ISDN stuff


search engine keywords: ISDN linux MPPP synchronous PPP syncPPP sync MPP RFC1717 isdn4linux isdn4kernel channelbundling bundling bonding
Note: The goal of this side is NOT to provide a nice designed ISDN-4-Linux fun page. I don't have the time to do this. All information is 'to the best of my knowledge and belief'.

Best viewed with any browser

For the current isdn4linux driver distribution just get the latest Linux Kernel Source tree from your favorite FTP site. Here in Tübingen try: ftp.uni-tuebingen.de
I currently recommend 2.0.36 with the _NEW_ util package (isdn4k-utils-3.0beta1!!!)

The kernel contains only the base kernel drivers. The utility package is on ftp.isdn4linux.de. Note: you can get the very latest version via CVS. I recommend this only for experts, so there is no description here how to get the files. (but you will find this (and many more) in the i4l-FAQ ).

The driver consists of several low level modules for different ISDN cards and a high level modul which implements a network interface, TTY drivers, audio drivers and a PPP protocol handler. Possible network protocols are IP, IP with type field, ethernetbridging, IP with CISCO-style HDLC. The PPP part implements IP in PPP encapsulation with (or without) VJ-Compression and MPPP (RFC1717) load sharing.
The lower protocols are implmented by the low level drivers. Usual is here: X75 X75UI, X75BUI, HDLC and so on ...

Some people are working on the Euro-File-Transfer protocol. If you're interessted in support for the EFT-protocol (or X.25 in general) you may wanna help them. (check this here for more)


Supported ISDN cards are: NOT supported cards are e.g: (if you have such a card call the manufacturer and moan)


Using ISDN PCMCIA cards and Linux

You should get the additonal PCMCIA ISDN card package e.g. from a Sunsite Mirror . There you find a Wrapper XXX_cs.o module you can put on top of a I4L driver stack. Check the package README for more.


FAX and ISDN4Linux.
That's REALLY a FAQ. As far as I know, none of the developer is willing to write an analog FAX emulation for isdn4linux. Maybe cards with an on board Modem solution will be supported in the future. If YOU wanna write a FAX emualation you may wanna search the net for the V.27, V.29, V.21, V.17, and T.30 specifications. Another good staring point may be: the Analog WWW server or this FAX package or this Fax software for a SGI machine.


Snapshots from the CVS tree at FTP.suse.com


For digital leased lines there is the ISACHSCX driver. This is NOT a low level driver for isdn4linux. It's a "raw" network device driver for Linux. Please READ the header of the ih.c file in the source code before using it! This driver is from November 1996. Alternate FTP site: here .

Note: The HiSax driver can now handle leased lines. Maybe, you give it a try.


Also available: some slides from the Linux Kongress 1996 in Berlin and some slides from the 26. DFN Betriebstagung . They are in german language.


Also check the home site of the i4l package.


Highly experimental. A proposed enhancement for isdn4linux called OKAPI . It's a programmable interface to the i4l subsystem. This package is for kernel 2.0.36 (vanilla) and 2.2.x (enhanced with latest CVS).

My first real application for this is a H.320 compatible video conferencing system. I finished an initial 'receive almost all and send precompressed streams' version a few weeks ago. It works limited with a T-View 100 and an Intel Proshare 100 on the remote side.
The major problem is my slow machine. There is no audio compression at the moment. The default audio format is 56kbit ulaw/alaw and therefore there isn't much bandwith left for video. There is no two or more B-channel support at the moment.
In this early state, I don't wanna make the package available.


Bandwith on demand for MPPP: ibod and XIBOD


Some people behind the isdn4linux project: View some snapshots from the isdn4linux developer meeting in Würzburg in January 1997.


Some help in configuring i4l can be obtained from:


To subscribe the i4l mailing list (mixed, but almost in german language), mail to: majordomo@hub-wue.franken.de with the word 'subscribe isdn4linux' in the BODY of the mail.
Last change: 18. Nov 1998
hippm@informatik.uni-tuebingen.de