Folks, An a= line is scoped by m= line. If an a= line appears in session level and is not overridden by an a= line of the same name in the media description then it's default and thus applies to all m= lines.
Quoting your example below: > v=0 > o=bob 2890844730 2890844731 IN IP4 host.example.com > s= > c=IN IP4 host.example.com > t=0 0 > m=audio 65422 RTP/AVP 0 > a=rtpmap:0 PCMU/8000 > m=video 0 RTP/AVP 31 > m=video 53000 RTP/AVP 32 > a=rtpmap:32 MPV/90000 > m=audio 51434 RTP/AVP 110 > a=rtpmap:110 telephone-events/8000 > a=recvonly The fourth m= line at port 51434 is the only "receiveonly" stream; all other media streams default to "sendrecv." --victor -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Christian Stredicke Sent: Tuesday, August 10, 2004 6:39 AM To: Christer Holmberg (JO/LMF) Cc: Sip-Implementors (E-mail) Subject: RE: [Sip-implementors] RFC3264 - where to put attributes when severalm-lines are available My feeling was that a-lines were associated with m-lines... I still dont understand how you would read the first SDP: Make the sessions (ports 65422, (0), 53000) sendrecv, and the audio session (port 51434) recvonly?! CS -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Christer Holmberg (JO/LMF) Sent: Monday, August 09, 2004 4:32 PM To: Christian Stredicke; Sip-Implementors (E-mail) Subject: RE: [Sip-implementors] RFC3264 - where to put attributes when several m-lines are available Hi, I guess your issue is valid for most media level attributes, ie should it be allowed to define them on the session level of the SDP, (similar to the c-line), in which case they should be associated with all media descriptors. For example, I had a discussion with Gonzalo if I can put a media label attribute on the session level, if I want to use the same label value for multiple streams. And so on... Or, is there any reason why only the specific mode attribute makes the whole thing "un-logical"? Regards, Christer Holmberg Ericsson Finland > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of > Christian Stredicke > Sent: 7. elokuuta 2004 23:13 > To: Sip-Implementors (E-mail) > Subject: [Sip-implementors] RFC3264 - where to put attributes when > several m-lines are available > > > I recently had a discussion where to put the a=sendrecv etc attributes > when there are several m-lines. The examples in RFC3264 seem to imply > that there is only one attribute per SDP. > > v=0 > o=bob 2890844730 2890844731 IN IP4 host.example.com > s= > c=IN IP4 host.example.com > t=0 0 > m=audio 65422 RTP/AVP 0 > a=rtpmap:0 PCMU/8000 > m=video 0 RTP/AVP 31 > m=video 53000 RTP/AVP 32 > a=rtpmap:32 MPV/90000 > m=audio 51434 RTP/AVP 110 > a=rtpmap:110 telephone-events/8000 > a=recvonly > > However, it would be more logical if the attribute is included in > every m-line segment. Like this: > > v=0 > o=bob 2890844730 2890844731 IN IP4 host.example.com s= c=IN IP4 > host.example.com t=0 0 m=audio 65422 RTP/AVP 0 a=rtpmap:0 PCMU/8000 > a=recvonly m=video 0 RTP/AVP 31 a=recvonly m=video 53000 RTP/AVP 32 > a=rtpmap:32 MPV/90000 > a=recvonly > m=audio 51434 RTP/AVP 110 > a=rtpmap:110 telephone-events/8000 > a=recvonly > > > Any ideas? > > > CS > _______________________________________________ > 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 _______________________________________________ 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
