Christer, I am not sure whether the fmtp attributes I listed is only a SENDING capability or not. Some of my colleagues argue that those attributes can also be RECEIVING capabilities. That's why I am looking for help on this mailing list for exact RFC quotation to prove it one way or the other. Somesh's point, whether directional attributes, sendonly, sendrecv, etc.. play a role here is indeed one of the confusing issue to me. As I have quoted in another email on this mailing list, RFC3264 does say that certain media parameters in fmtp attributes may be interpreted according to specific media RFCs, in my case, RFC3016. But I can't find comments regarding this in RFC3016. Thanks for your advice. Fan
-----Original Message----- From: Christer Holmberg (JO/LMF) [mailto:[EMAIL PROTECTED] Sent: Friday, November 04, 2005 1:16 AM To: Somesh S Shanbhag ; [EMAIL PROTECTED]; Ling, Fan; [email protected] Subject: RE: [Sip-implementors] media description in SDP is for sender orreceiver? Hi, I think you missunderstood Ling's question. Normally a user describes his RECEIVING capabilities in the SDP ("I am able to receive these codecs on this port" etc etc etc). But, for MPEG-4, I believe Ling's point was tha the fmtp attribute refered to actually describes a SENDING capability (not related to whether the stream is sendrecv, sendonly, or something else...). Or, was it ME who missunderstood the question? :) Regards, Christer -----Original Message----- From: [EMAIL PROTECTED] To: Ling, Fan; [email protected] Sent: 4.11.2005 6:32 Subject: Re: [Sip-implementors] media description in SDP is for sender orreceiver? Hi, RFC 3264 specifies sendonly, recvonly, sendrecv and inactive attributes. UA can specify any of these attributes according to it's preference. When no such attribute is present, it is assumed that the stream is "sendrecv" stream and whatever the encodings specified applies to both sender and receiver side. Regards Somesh S. Shanbhag --- "Ling, Fan" <[EMAIL PROTECTED]> wrote: > Hi, > > The following SDP message describes a MPEG4 video > bitstream: > > > > m=video 20000 RTP/AVP 98 34 > > a=rtpmap:98 MP4V-ES/90000 > > a=fmtp:98 > profile-level-id=8;config=000001B008000001B5090000010000000120008440FA28 > 2C2090A21F > > > > Does this SDP message describes the sender encoder > generated media > settings or the required media settings on the > receiver's encoder? Or > both? Can some one point me to the proper RFCs? I > believe this media > settings is for the sender side, but I can't find > definitely > description in any RFCs. > > Thanks a lot > > Fan > > _______________________________________________ > Sip-implementors mailing list > [email protected] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > ----------------------------------------- SIMPLICITY IS THE BEAUTY. BE NATURAL LIVE NATURAL. ----------------------------------------- Somesh S. Shanbhag Focus Area - VoIP Team (FA-VoIP) Mascon Global Communication Technologies Enterprise of Mascon Global Limited #59/2, 100Ft Ring Road Banashankari II stage Bangalore-560070 Karnataka INDIA Website: http://www.masconit.com ----------------------------------------- __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
