[Asterisk-Dev] IAX2 Spec?

[Derek Smithies]

Hi,

> Michael Giagnocavo wrote:
> 
> >I've been working on improving the IAX2 firmware for the PA168. It's no fun
> >working from Ethereal and reverse engineering Asterisk :). 
yup,
 it is no fun working from ethereal and reverse engineering Asterisk to 
see how iax2 works.
Ethereal 0.10.10 has been released, and does a reasonable job of decoding 
iax2 packets. Earlier versions of ethereal would crash when attempting to 
decode some packets. 
The code is, well, not 100% clear.

> 
> http://voip.cornfed.com/index.php?p=7
> 
> There's a PDF of an RFC here.
yes - it is a great start.
However, missing bits of information are:
Description of the 52 (or is it more) Information Elements
Description of which IEs are used in which full frame packets
Description of what iseqno/oseqno and timestamp are used in ack frames
Description of the finer points of full frames. Like lagrq and lagrp 
frames. Resends of lagrq and lagrp is not allowed - as this makes the 
calculation of the roundtrip time a bit difficult.
Description of the trunking mechanism
Description of the encryption mechanism

other than those few things, the document is a good start.




Derek.
-- 
Derek Smithies Ph.D.                         
IndraNet Technologies Ltd.                
Email: derek at indranet.co.nz         
ph +64 3 365 6485                          
Web: http://www.indranet-technologies.com/