[OpenSIPS-Devel] media proxy with sangoma

Saúl Ibarra Corretgé saul at ag-projects.com
Thu Aug 26 17:03:30 CEST 2010


On 08/26/2010 04:53 PM, Dominique Broeglin wrote:
> Hi,
>
> My idea was to parse the SDP and determine if transcoding is needed on the invite and/or on the responses. Then given what is read, if transcoding is required:
> 	Alice --- media-proxy --- transcoding card --- media-proxy --- Bob
> if no transcoding is required:
> 	Alice --- media-proxy --- Bob
>

But by the time you have all that information, it's too late (at least 
for OpenSIPS) to do anything about it. It'd have to be dealt within 
MediaProxy.

> It's the simplest way I found to be able to decide to use transcoding or not on the fly. What do you think of this approach ? I agree it's complicated but re-INVITEs come with their own issues in heterogeneous environments.
>

I still don't understand how would you put the transcoding card 'in the 
middle'. And also, the SDP must be fixed, because endpoints will need to 
know in what codec they are talking.

This last thing could be faked by always adding G729 to the offer and 
answer, but I've seen some devices fail if they get more than one codec 
as an answer.


Regards,

-- 
Saúl Ibarra Corretgé
AG Projects



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