Based on kernel version 4.1. Page generated on 2015-06-28 12:13 EST.
1 Linux X.25 Project 2 3 As my third year dissertation at University I have taken it upon myself to 4 write an X.25 implementation for Linux. My aim is to provide a complete X.25 5 Packet Layer and a LAPB module to allow for "normal" X.25 to be run using 6 Linux. There are two sorts of X.25 cards available, intelligent ones that 7 implement LAPB on the card itself, and unintelligent ones that simply do 8 framing, bit-stuffing and checksumming. These both need to be handled by the 9 system. 10 11 I therefore decided to write the implementation such that as far as the 12 Packet Layer is concerned, the link layer was being performed by a lower 13 layer of the Linux kernel and therefore it did not concern itself with 14 implementation of LAPB. Therefore the LAPB modules would be called by 15 unintelligent X.25 card drivers and not by intelligent ones, this would 16 provide a uniform device driver interface, and simplify configuration. 17 18 To confuse matters a little, an 802.2 LLC implementation for Linux is being 19 written which will allow X.25 to be run over an Ethernet (or Token Ring) and 20 conform with the JNT "Pink Book", this will have a different interface to 21 the Packet Layer but there will be no confusion since the class of device 22 being served by the LLC will be completely separate from LAPB. The LLC 23 implementation is being done as part of another protocol project (SNA) and 24 by a different author. 25 26 Just when you thought that it could not become more confusing, another 27 option appeared, XOT. This allows X.25 Packet Layer frames to operate over 28 the Internet using TCP/IP as a reliable link layer. RFC1613 specifies the 29 format and behaviour of the protocol. If time permits this option will also 30 be actively considered. 31 32 A linux-x25 mailing list has been created at vger.kernel.org to support the 33 development and use of Linux X.25. It is early days yet, but interested 34 parties are welcome to subscribe to it. Just send a message to 35 firstname.lastname@example.org with the following in the message body: 36 37 subscribe linux-x25 38 end 39 40 The contents of the Subject line are ignored. 41 42 Jonathan 43 44 email@example.com