"Ian" wrote in message
om...
Greetings,

I'm part of a student team working on developing AX.25 code
for an amature satellite application. We have been considering
both versions 2.0 and 2.2 but are not clear on the differences
between the two, if any. Does anyone have a good enough
understanding to explain them to me? Thank you.

That would be a good homework project, but not really all
that useful, just implement using the 2.2 specification.

Consider adding the PE1CHL enhancements, per the ARRL
networking conference procedings, Volume 14 I think.

Might as well design for these from the start, the protocol
works much better if you include them:

Extended sequence numbers via SABME.
No fixed maximum frame size.
Adaptive FRACK via measured RTT.
Slow start a la TCP.
Selective reject and out-of-sequuece receive frame queueing.

Good research projects:

Adaptive frame size.
Is FRMR really useful?

There is a good deal of source code available, some good,
some very bad. Google will turn it up for you.

--

... Hank

Hank: http://horedson.home.att.net
W0RLI: http://w0rli.home.att.net