draft-ietf-sipping- offeranswer- 02 Primary author: Takuya Sawada Presenting: Paul Kyzivat IETF-69 July,2007

Status In queue for WGLC, scheduled for 13-aug-07 Version -01, after Prague –Incorporated responses to comments received (AFAIK) except for issue below –added section of guidelines for how to construct offers and answers Response to requests long ago Little if any comment on this yet. Please look. Version -02 ready –(missed submission window. Available on external server.) –just editorial changes Believe there is (only) one remaining issue lacking consensus. If we can settle that here, believe is ready for WGLC.

Issue: sip-session vs. SDP session First raised (I think) by Vijay Gurbani Question: what happens if sdp session-id is changed in a sip session? This is MUST NOT in RFC There are reports of this being seen in the wild –but with two conflicting interpretations :-(

Issue: sip-session vs. SDP session Interpretation 1 The o-line is simply ignored. The rules of RFC 3264 are applied –as if each subsequent offer and answer has identical o-line to prior sdp in same direction –except with version increased by one.

Issue: sip-session vs. SDP session Interpretation 2 Each change in the session-id in the o-line signals the beginning of a new sdp session. Follows the rules for an initial offer or answer –Rather than being treated as a modification to prior offer or answer

Issue: sip-session vs. SDP session Proposal This usage is clearly invalid according to RFC 3264 Propose that we leave it that way –offeranswer draft to reiterate Those wanting a new sip session can achieve that using INVITE/Replaces

Next Steps Proceed with WGLC as planned (13-aug) –Need some reviewers