x25.txt 2.0 KB

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  1. Linux X.25 Project
  2. As my third year dissertation at University I have taken it upon myself to
  3. write an X.25 implementation for Linux. My aim is to provide a complete X.25
  4. Packet Layer and a LAPB module to allow for "normal" X.25 to be run using
  5. Linux. There are two sorts of X.25 cards available, intelligent ones that
  6. implement LAPB on the card itself, and unintelligent ones that simply do
  7. framing, bit-stuffing and checksumming. These both need to be handled by the
  8. system.
  9. I therefore decided to write the implementation such that as far as the
  10. Packet Layer is concerned, the link layer was being performed by a lower
  11. layer of the Linux kernel and therefore it did not concern itself with
  12. implementation of LAPB. Therefore the LAPB modules would be called by
  13. unintelligent X.25 card drivers and not by intelligent ones, this would
  14. provide a uniform device driver interface, and simplify configuration.
  15. To confuse matters a little, an 802.2 LLC implementation for Linux is being
  16. written which will allow X.25 to be run over an Ethernet (or Token Ring) and
  17. conform with the JNT "Pink Book", this will have a different interface to
  18. the Packet Layer but there will be no confusion since the class of device
  19. being served by the LLC will be completely separate from LAPB. The LLC
  20. implementation is being done as part of another protocol project (SNA) and
  21. by a different author.
  22. Just when you thought that it could not become more confusing, another
  23. option appeared, XOT. This allows X.25 Packet Layer frames to operate over
  24. the Internet using TCP/IP as a reliable link layer. RFC1613 specifies the
  25. format and behaviour of the protocol. If time permits this option will also
  26. be actively considered.
  27. A linux-x25 mailing list has been created at vger.kernel.org to support the
  28. development and use of Linux X.25. It is early days yet, but interested
  29. parties are welcome to subscribe to it. Just send a message to
  30. majordomo@vger.kernel.org with the following in the message body:
  31. subscribe linux-x25
  32. end
  33. The contents of the Subject line are ignored.
  34. Jonathan
  35. g4klx@g4klx.demon.co.uk