mirror of https://gitee.com/openkylin/linux.git
45 lines
2.0 KiB
Plaintext
45 lines
2.0 KiB
Plaintext
|
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
|