comment below... Attila Sipos wrote: > > > Hi, > > If an endpoint A sends SDP containing "m=" and "a=" lines > like this: > > m=audio 10036 RTP/AVP 8 119 > a=rtpmap:8 PCMA/8000 > a=rtpmap:119 telephone-event/8000 > > I understand this to mean that the sender of this SDP > wishes to receive DTMF in an RFC2833 RTP stream with > an RTP payload of 119. > > > If the replying endpoint B, send an SDP with the > following "m=" and "a=" lines: > > m=audio 10022 RTP/AVP 8 97 > a=rtpmap:8 pcma/8000 > a=rtpmap:97 telephone-event/8000 > > Then I understand this to mean that this person wishes > to receive an RFC2833 RTP stream with an RTP payload > of 97. > > > So, if I am right, endpoint A should send RFC2833 RTP > with an RTP payload of 97. > > And endpoint B should send RFC2833 RTP with an > RTP payload of 119. > > Is my understanding correct?
IMO, this is one main "deficiency" with SDP (RFC 2327) in SIP. Since there are no direction attributes in the above, it would seem that neither endpoint will "communicate" telephone-events to the other. Neither endpoint has agreed on the payload type that they will both send and receive with. If the endpoints want to use a different payload type for a specific encoding, they need to be explicit IMHO about which value they'll use in each direction. Regards, Bert > > Any help is greatly appreciated. > > Thanks, > > Attila > > > > Attila Sipos > Software Engineer > > <mailto:[EMAIL PROTECTED]> > <http://www.vegastream.com> > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
