[OpenSIPS-Users] Route selection based on SDP codecs

Jeff Pyle jpyle at fidelityvoice.com
Mon Nov 2 17:21:39 CET 2009


John,

That's a great idea...  Regarding (a), have you looked the codec_* functions
available in 1.6's textops?  The codec_exists() function will return back
true if a particular codec is available in the existing SDP.  Perhaps this
functionality could be extended to return an AVP to give the numerical
priority of the codec as well.



- Jeff




On 11/2/09 11:06 AM, "John Quick" <John.Quick at smartvox.co.uk> wrote:

> If a call is has G.729 set as the preferred codec in the SDP, I want to send
> it to an Asterisk server
> with transcoding capabilities. If the preferred codec is G.711 I will send it
> directly to the media
> server, gateway or other destination.
> 
> I can use TEXTOPS to search for entries like this in the SDP:
> m=audio 10004 RTP/AVP 18
> a=rtpmap:18 G729/8000
> 
> (a) Is there a better way than using regular expression searches of the
> message body?
> (b) How certain is it that G.729 will always use 18 to identify it in the SDP?
> 
> Many thanks.
> 
> John Quick
> Systems Consultant
> Smartvox Limited




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