Yes, it is correct as per section 6.1 of RFC3264. "For streams marked as sendrecv in the answer, the "m=" line MUST contain at least one codec the answerer is willing to both send and receive, from amongst those listed in the offer. The stream MAY indicate additional media formats, not listed in the corresponding stream in the offer, that the answerer is willing to send or receive (of course, it will not be able to send them at this time, since it was not listed in the offer)."
Regards Satya T -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of harneet billing Sent: Wednesday, July 29, 2009 6:49 PM To: [email protected] Subject: [Sip-implementors] Query regarding 'm' line in 200 OK Hi All, I had a query regarding a general SIP INVITE scenario. A ------------------ B (UAC) (UAS) Now assume that A sends an INVITE to B mentioning that it supports G711 MuLaw. v=0 o=user1 53655765 2353687637 IN IP4 10.253.6.209 s=- c=IN IP4 10.253.6.209 t=0 0 m=audio 6000 RTP/AVP *0* a=rtpmap:*0* PCMU/8000 Can B while responding in its 200 OK, add a few more things in the 'm' line as mentioned below? v=0 o=SHOUT 0 0 IN IP4 10.253.6.249 s=SIP call via SHOUT c=IN IP4 10.253.6.249 t=0 0 m=audio 17184 RTP/AVP 0 *13 101* a=rtpmap:0 PCMU/8000 a=rtpmap:*13* CN/8000 a=rtpmap:*101* telephone-event/8000 a=fmtp:*101* 0-15 Is this behavior correct on part of B ? Regards, Harneet _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
