Yes this is valid. When you make an SDP offer, you are saying you are willing to receive any of those codecs at anytime during the session. See the third paragraph of this section: http://tools.ietf.org/html/rfc3264#section-5.1
"If multiple formats are listed, it means that the offerer is capable of making use of any of those formats during the session. In other words, the answerer MAY change formats in the middle of the session, making use of any of the formats listed, without sending a new offer." Mike On 17 April 2015 at 12:47, NK <nitinkapo...@gmail.com> wrote: > Dear All, > > I am facing the problem where my vendor changed the codec in RTP > packet only. Below is the explanation to this issue. > > 1) We sent the Invite to vendor and Vendor replied 183 w/SDP along with > below m line. Also since its early media RTP started and agreed to use G729 > Codec as below and UAC is also agreed on same. > > m=audio 21280 RTP/AVP 18 8 101 > > RTP > > Media Destination Port = 41354 > Direction = InBound > *Payload = G.729* > > 2) Here after we received 180 w/SDP from vendor and SDP remain the same, > but the RTP packet which redirect to UAC from UAS changed the codec as > below. > > m=audio 21280 RTP/AVP 18 8 101 > > RTP > > Media Destination Port = 41354 > Direction = InBound > *Payload = PCMA* > > Can you please help me on this if this is accetpable and i cannot see much > information on this. > > Thank you in advance. > > Regards, > Nitin Kapoor > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
