Thanks Paul and everyone ... I am designing Phone1 to use only one audio and one video. Phone1 supports secured media as well. so it is offering both secure/non secure to phone2 and expects phone2 to select among the given m-lines (RTP and SRTP).
Thanks. On Wed, Apr 16, 2014 at 7:54 PM, Paul Kyzivat <[email protected]> wrote: > I read a number of the replies to this, but couldn't find an obvious place > to jump in, so I'm just replying here. > > An offer multiple audio and/or video m-lines does not mean that they are > *alternatives*. Absent some explicit indication, there is no way to know > what the offerer's intent is in offering them, nor does the offerer know > what the answerer's intent is in accepting them. > > In the given example, if the offerer only intends to use one audio and one > video, then it can arbitrarily choose one, and hope that this works > reasonably for the answerer. In that case it should do another O/A and > reject the ones it doesn't intend to use. > > If you are designing phone1, and your goal is to have one audio and one > video, but you want to offer more possibilities than you can express with > one audio and one video m-line, then post back with what you are trying to > accomplish, and we can discuss recommended ways of achieving that. > > Thanks, > Paul > > > On 4/16/14 2:51 AM, isshed wrote: >> >> Hi All, >> >> I have 1 basic query regarding ofer-answer model >> >> >> Phone1 is sending the offer with 2 audio mlines and 2 video mline like >> as follows. >> >> >> m=audio 3342 RTP/SAVP 0 8 127 >> a=crypto:7 AES_CM_128_HMAC_SHA1_80 inline:2222222222 >> a=rtpmap:0 PCMU/8000 >> a=rtpmap:8 PCMA/8000 >> a=rtpmap:127 telephone-event/8000 >> m=audio 3342 RTP/AVP 0 8 127 >> a=rtpmap:0 PCMU/8000 >> a=rtpmap:8 PCMA/8000 >> a=rtpmap:127 telephone-event/8000 >> m=video 5544 RTP/SAVP 109 >> a=crypto:8 AES_CM_128_HMAC_SHA1_80 inline:3333333333 >> a=rtpmap:109 H264/90000 >> a=fmtp:109 profile-level-id=42800d >> m=video 5544 RTP/AVP 109 >> a=rtpmap:109 H264/90000 >> a=fmtp:109 profile-level-id=42800d >> >> and phone 2 is responding with all the 4 m lines as follows >> >> m=audio 4344 RTP/SAVP 0 8 127 >> a=rtpmap:0 PCMU/8000 >> a=rtpmap:8 PCMA/8000 >> a=rtpmap:127 telephone-event/8000 >> m=audio 4344 RTP/AVP 0 8 119 >> a=sendrecv >> a=rtpmap:0 PCMU/8000 >> a=rtpmap:8 PCMA/8000 >> a=rtpmap:119 telephone-event/8000 >> a=fmtp:119 0-15 >> m=video 7878 RTP/SAVP 109 >> a=crypto:8 8 AES_CM_128_HMAC_SHA1_80 inline:4444444444 >> a=rtpmap:109 H264/90000 >> a=fmtp:109 profile-level-id=42800d >> m=video 7878 RTP/AVP 109 >> a=sendrecv >> a=rtpmap:109 H264/90000 >> a=fmtp:109 profile-level-id=42801e; max-mbps=49000; max-br=20010; >> sar=13 >> >> >> >> >> Which m line should phone1 select to send and receive audio and video. >> >> let me know is query is not clear. >> >> >> Thanks, >> _______________________________________________ >> Sip-implementors mailing list >> [email protected] >> https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors >> > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
