[OpenSIPS-Users] mediaproxy bug with offer answer in different transaction

[Saúl Ibarra Corretgé]

Hi Eric,

On Jun 11, 2014, at 4:53 PM, Eric Tamme wrote:

> Hi Saúl, and others,
> 
> We have discovered a bug in mediaproxy where it does not recognize an answer that is part of a different transaction, this is caused by how mediaproxy tracks offer/answer based on cseq.  Here is the example offer answer scenario from RFC3262 that does not work.
> 
> UAC  INVITE Cseq: 1 (no SDP offer) ->
> 
> <- 183 with SDP offer
> 
> PRACK CSeq: 2, Rseq: 1  with SDP answer->
> 

Wow, what an abomination of a use-case, I didn't know it was even possible to do that :-/

> Because the PRACK is a different transaction, and has a different CSeq than the offer, mediaproxy assumes it is a new offer, rather than an answer.
> 
> Can you offer any thoughts on what might be the best way to fix this issue?  We are happy to work on a patch as well - but would like to have input from the maintainers so that we can be sure it would be accepted upstream.
> 

The OpenSIPS mediaproxy module just takes some information and passes it to the MediaProxy dispatcher process, so the fix needs to take place in mediaproxy/mediacontrol.py, in the update_session and/or update_media functions.

Let me know how that goes!


Cheers,

--
Saúl Ibarra Corretgé
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