So is there any means to indicate that both G.729 and G.711 are mandatory and both are required?
Regards Ranjit -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Stephane van Hardeveld Sent: Wednesday, February 25, 2009 5:04 PM To: Iñaki Baz Castillo; Klaus Darilion Cc: sip-implementors Subject: Re: [Sip-implementors] asymmetric audio codecs ----- Original Message ----- From: "Iñaki Baz Castillo" <i...@aliax.net> To: "Klaus Darilion" <klaus.mailingli...@pernau.at> Cc: "sip-implementors" <Sip-implementors@lists.cs.columbia.edu> Sent: Wednesday, February 25, 2009 12:20 PM Subject: Re: [Sip-implementors] asymmetric audio codecs > 2009/2/25 Klaus Darilion <klaus.mailingli...@pernau.at>: >> I think if Alice announces G711 and G729, and Bob answers with G.729, >> Alice must send with G729 and Bob can send with G711 too. Is this >> correct? > > If Bob answers G729 then Alice expects that Bob will send G729. > But if Bob sends G711, how will detect Alice that the incoming RTP is not > G729? > The negoziation is supposed to have place during the SDP exchange and > it must be deterministic, am I wrong? > Agreed. If you really would like to use both G711 and G729 for sending to Alice, you would have to include two seperate media definitions, as far as I understand rfc 3264, par 5.1: In all cases, the formats in the "m=" line MUST be listed in order of preference, with the first format listed being preferred. In this case, preferred means that the recipient of the offer SHOULD use the format with the highest preference that is acceptable to it. And a bit further (type is here audio/video or ...): If multiple media streams of the same type are present in an offer, it means that the offerer wishes to send (and/or receive) multiple streams of that type at the same time. ... Stephane van Hardeveld _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
