> Hello, > > I am working on testing against an ITSP. When I go to > transfer a call to our park server, I send a re-INVITE with > no SDP. The endpoint on the ITSP side returns the previously > negotiated codec in the OK rather than the list of codecs > that it supports. In this case, it returns > G729 which is the codec that it negotiated on the initial > call. Is this a valid response. Does this mean that the > ITSP simply does not support codec renegotiation?
It is legal to create an SDP offer containing a single codec which effectively imposes a particular codec for the media session. Reasons for doing this include the following: - endpoint only supports one codec; - in re-negotiation scenarios, endpoint cannot or does not want to change codecs. Having said that, providing an SDP offer with a single codec being g.729 may not be a good idea if it can be avoided as not every endpoint supports it resoling in a failed media negotiation. _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev
