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