Hi I believe It depends on implementation also. The client can send reinvite with port zero for unwanted m-lines or it can send SRTP directly. We have tested RTP/AVPF and RTP/AVP with 4 m-lines ,if the answerer responds with 4 valid m-lines then we prefer RTP/AVPF and starts sending media. Our customer don't want lockdown reinvite so we implemented in this way.
Regards Sesh -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Brett Tate Sent: Wednesday, April 16, 2014 3:05 PM To: Gaurav Kumar; isshed; sip-implementors Subject: Re: [Sip-implementors] SDP offer answer model Hi, If I recall correctly, there are MMUSIC RFCs (such as maybe RFC 6871) which can potentially be used to clearly communicate to answerer that it prefers only specific combinations of audio and video to be successfully answered. This could potentially help avoid the need for subsequent offer/answer negotiation to 0 out the extra audio and video media. > -----Original Message----- > From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip- > implementors-boun...@lists.cs.columbia.edu] On Behalf Of Gaurav Kumar > Sent: Wednesday, April 16, 2014 4:27 AM > To: isshed > Cc: sip-implementors > Subject: Re: [Sip-implementors] SDP offer answer model > > Hi, > > This Offer-Answer is use-case of supporting multiple m-line for SRTP. > The answerer does support SAVP (for media encryption). > Ideally, Answerer should keep the port zero for audio and video > m-lines with RTP/AVP and non-zero port for audio and video m-lines > with RTP/SAVP (if the answerer want to establish SRTP call with the > Offerer) > > Offerer can accept all the m-lines in the answer, and then send > reinvite where it can update m-line with port zero for RTP/AVP for > audio and video m-lines. > > From RFC perspective, the answerer is behaving correctly. > > Thanks, > Gaurav > > -----Original Message----- > From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip- > implementors-boun...@lists.cs.columbia.edu] On Behalf Of Brett Tate > Sent: Wednesday, April 16, 2014 1:49 PM > To: isshed; sip-implementors > Subject: Re: [Sip-implementors] SDP offer answer model > > > Which m line should phone1 select to send and receive audio and > video. > > From an offer/answer perspective, all of the m lines. > > -- > > > This email is intended solely for the person or entity to which it is > addressed and may contain confidential and/or privileged information. > If you are not the intended recipient and have received this email in > error, please notify BroadSoft, Inc. immediately by replying to this > message, and destroy all copies of this message, along with any > attachment, prior to reading, distributing or copying it. > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > This is confidential Ittiam property. > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors -- This email is intended solely for the person or entity to which it is addressed and may contain confidential and/or privileged information. If you are not the intended recipient and have received this email in error, please notify BroadSoft, Inc. immediately by replying to this message, and destroy all copies of this message, along with any attachment, prior to reading, distributing or copying it. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
