Ethereal-dev: [Ethereal-dev] Re: [Ethereal-users] How to make ethereal recognise RTP,RTCP,SCTP

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From: andreas.sikkema@xxxxxxxxxxx
Date: Thu, 27 Jun 2002 09:22:34 +0200
> RTP and RTCP don't have standard port numbers, and nobody's figured out
> any heuristic to guess whether a UDP packet is an RTP or RTCP packet or
> not; 

Hmm, I was just thinking, 
- Check if the version is in the correct range (0-3 or something)
- Check if the length of the received UDP data is the same as the 
  length the RTP/RTCP message says it is
- For RTP you could also check if the mediatype is in the correct range.
- For RTCP you could check if walking the SSRC parts ends up at the end 
  of the message (or at the start of padding)
- Check if the padding stuff also matches? This one I'm not sure about.

This is all from the head, no RFC on hand at the moment, so....

But I don't have enough experience with heuristics to be able to predict 
how precise this is.

-- 
Andreas Sikkema
andreas.sikkema@xxxxxxxxxxx
"While you're waiting, read the free novel we sent you. 
 It's a Spanish story about a guy named `Manual'" - Dilbert