But if the UA reject the media by setting it the port to 0, there will be no media streams in the call. Because according to rfc 3264 : Existing media streams are removed by creating a new SDP with the port number for that stream set to zero. Removal of a media stream implies that media is no longer sent for that stream, and any media that is received is discarded. In the case of RTP, RTCP transmission also ceases, as does processing of any received RTCP packets. Any resources associated with it can be released.
There is no hint in which moment the media is released. When the SDP offer is sent or when the SDP answer is received. Does the failure of re-INVITE means that the negotiated media stream still exists? -----Original Message----- From: Rohit Aggarwal [mailto:[EMAIL PROTECTED] Sent: Thursday, September 18, 2008 2:46 PM To: Neranza Bundova; [email protected] Subject: RE: reject sdp offer with multiple media lines Hi If UAC (party A) adds a new media stream in the Re-INVITE, UAS (party B) can always reject it by setting port to 0. UAC should release any resources reserved for the new stream on getting offer rejection from the UAS. Further, failure of Re-INVITE does not necessarily cause the call to fail. UAC can revert media changes to the previous state and session can continue with the previously negotiated media parameters. Regards Rohit Aggarwal Aricent -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Neranza Bundova Sent: Thursday, September 18, 2008 4:48 PM To: [email protected] Subject: [Sip-implementors] reject sdp offer with multiple media lines Hi All, I am not sure how a user agent should reject an offer when: UA "A" and UA "B" are in call and they have negotiated an audio session. UA "A" sends re-INVITE request to "B" with SDP that rejects the media by setting the port number to 0. UA "A" adds another media to the SDP offer that "B" understand but can not accept. 1. When UA "A" should release the resource used for the media stream? a. when an sdp answer from "B" is received b. when "A" sends the sdp offer. 2. What B will do in this situation? a. Will send sdp answer with all media ports set to 0? Should B close the dialog b. Will send 488 response i. A will close the dialog ii. A and B will continue the dialog and will use already negotiated media stream _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error,please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus." _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
