ref: draft-ietf-mmusic-sdp-offer-answer-02.txt
I'm looking at section "10.2 One of N Codec Selection". At the end, there is the sentence: The protocol which carries offers and answers has to provide a means to resolve these glare conditions, so that only one offer will be used. This seems to me that: if an offer has multiple codecs then, eventually, you MUST be left with JUST ONE selected codec. Is my above statement correct? Or can you actually select two codecs if you want to. The reason I ask is that I'm trying to understand the interoperability issues associated with RFC2833. Some vendors might "offer" an SDP like this: m=audio 10016 RTP/AVP 4 8 97 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:97 telephone-event/8000 Seeing as they've offered a "telephone-event" codec AND some "normal audio" codecs, I believe their intention is to do BOTH "telephone-event" and "normal audio". However, I also believe that with this offer they will only be allowed to do ONE of these! Is this correct? So, I believe that any endpoint that wishes to do BOTH "normal audio" AND "telephone-event" media MUST use separate "m=" lines. i.e. the offer should be: m=audio 10016 RTP/AVP 4 8 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 m=audio 10018 RTP/AVP 97 a=rtpmap:97 telephone-event/8000 Is this correct? Any help is much appreciated. Regards, Attila Attila Sipos Software Engineer <mailto:[EMAIL PROTECTED]> <http://www.vegastream.com> ____________________________________________________________________________ ______ VegaStream : A World of difference for your Integrated Communications EMEA Office (UK) Tel + 44 - 1344 784900 Fax + 44 - 1344 784901 USA Office Tel + 1 - 561-995-2300 Fax + 1 - 561-995-2600 This e-mail and any attachments hereto are strictly confidential and intended solely for the addressee. If you are not the intended addressee please notify the sender by return and delete the message. You must not disclose, forward or copy this e-mail or attachments to any third party without the prior consent of the sender. _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
