Draft Minutes for SIP at IETF 67 Edited by Dean Willis Based on notes by David Bryan, Spencer Dawkins, Jason Fischl, Philip Mathews, Chris Boulton, Richard Barnes, and Others. Session 1: Thursday 1300-1500 Grand Ballroom C Topic: Agenda Bash and Status Discussion led by Chairs Slides included in proceedings. Agenda accepted as presented Working group members asked to more thoroughly review the certs draft and consent framework. Topic: Outbound led by Rohan Mahy Read: draft-ietf-sip-outbound-05 Slides included in proceedings. Changes since last version reviewed. Issue: Which response code to use for failures. No objection noted to proposed use of 430 Flow Failed. Issue: Noted that there is no mention of rport in the draft. Author will add text explaining that UA must put rport parameter in Via and send from port it's prepared to receive on, and add informative reference to NAT scenarios document. Issue: Verify outbound support on first or all hops? Discussion seemed to resolve on checking at registrar and first hop. Author will make appropriate changes to the document. Issue: How to resolve possible mismatch in max-flows parameter between visited proxy and home proxy? Discussion of this question was inconclusive, with a general consensus to defer further discussion. Issue: Detecting instance-ID binding rules. This relates to concerns raised by 3GPP. A side meeting with 3GPP was held, and the author thinks he understands the problem and will propose a solution in the next revision of the document. The expected approach is to relax the flow-token language somewhat to allow the specific use case proposed by 3GPP. Topic: Domain Certs led by Vijay Gurbani Slides included in proceedings. Read: draft-gurbani-sip-domain-certs-03 The use of embedded DNS names to indicate the purpose of a certificate was quite controversial and much discussion ensued. The security community holds that extended certificates may be a better solution. Discussion of the document touched on whether the work is required and how it relates to other work. The discussion was inconclusive, and we expect to resolve it via list discussion and possibly a subject-specific conference call. Topic: Connection Reuse led by Vijay Gurbani Slides included in proceedings Read: draft-ietf-sip-connect-reuse-07 Issue: Since the impact of this work has essentially declined to halving the number of TLS between proxies not separated by NATs, should we continue to pursue the work? The opinion of the room was weighted about 5 to 1 against continuing the work. The chairs are tasked to raise this question on the mailing list. Issue: The approach taken by the outbound mid-dialg draft may obviate some of the applicability for this draft. Discussion on this point was inconclusive, and it will be taken as a topic for an upcoming conference call. Issue: The CP behavior in this document contradicts that in draft-ietf-sip-outbound. Topic: SIPS Guidelines led by Francois Audet Slides included in proceeedings Read: draft-audet-sip-sips-guidelines-04 Changes in document since last version reviewed. Issue: 4 point BCP list proposed on-list by Dean Willis. Noted that Item 1 is somewhat out of place, as it simply restates RFC 3261. Suggested that a BCP should perhaps explicitly state this as a "reminder". The room seemed to agree with points 2 and 3. Point 4 remained controversial, with a general consensus emerging that it should be expressed at a "Should" strength along with discussion of the risk model and consequences. Topic: GRUU and Supporting Drafts Led by Jonathan Rosenberg Slides included in proceedings Read: draft-ietf-sip-gruu-11,draft-rosenberg-sip-ua-loose-route-00 Change since last version reviewed. Issue: GRUU subtype names. The room demonstrated a slight preference for the names used in -11 over known alternatives, but nobody seems particularly enamored with these names and the floor remains open to suggestions. Discussion on ua-loose-route draft deferred to next session. Session 2: Friday 0900-1130 Grand Ballroom C Topic: UA-loose-route, continued from previous session. Consensus noted that we do need some sort of solution for the general problem of delivery of URI parameters across contact-routing operations. Issue: Concerns raised about backward compatibility. Noted that compliant P-CSCF should be OK. Suggested that we have a design team revisit call-flows and analyze for backward compatibility issues. Issue: Does GRUU normatively depend on this work? Resolved: GRUU does not reference this document. However, some participants feel it should, as the benefit of GRUU cannot be fully recognized in the absence of this specification. The chairs asked for a hum, and the consensus of the room is that GRUU and ua-loose-route can proceed independently. Question: Adopt this draft as baseline text for a WG effort, should the ADs approve the milestone? Consensus to adopt noted by chairs. To-do: Chairs to work with AD to set new milestone. Topic: Location Conveyance led by James Polk and Brian Rosen Slides included in proceedings Read: draft-ietf-sip-location-conveyance-05 Changes since last version reviewed. The room discussed trust issues, location-by-value (needs geolocation), and the question of whether it is important to know which entity inserted a location. No changes to the document were noted as being required during this discussion. The chairs polled for acceptability of current direction -- adding to a header. There were no objections noted to this direction. Issue: Where to track the location error created by this draft? Proposed that we have separate registries for SIP and LOST. Further discussion deferred to list and future conference call. To-do: Chairs to establish a conference call for discussion. Topic: Connected Identity led by John Elwell Slides included in proceedings Read: draft-ietf-sip-connected-identity-02 Current status reported as all issues fixed exception for rejection by RFC 4474 verifier. Discussion concluded with a proposal to not make a statement about 428 responses and policy, perhaps add an informational header into a mid-dialog request rather than rejecting outright. Author will work with this approach and revise doc appropriately. Topic: Identity Coexistence led by Jonathan Rosenberg slides included in proceedings Read: draft-rosenberg-sip-identity-coexistence-00 Issue: How to deal with transit networks? This produced an extensive discussion. Proposed that logic in draft is inverted, and that we should perhaps be looking for Identity and falling back to PAID. There seems to be some consensus that this work is valuable, although there is no consensus yet on the documented approach. The author will revise the document for further discussion. Topic: Outbound Discovery and Mid-Dialog Requests led by: Jonathan Rosenberg Slides included in proceedings Read: draft-rosenberg-sip-outbound-discovery-mid-dialog-00 Issue: How to discover in the absence of DNS? There appears to be no consensus on whether this is a requirement. Further discussion deferred to list. Topic: Diagnostic Responses led by Scott Lawrence Slides included in proceedings Read: draft-ietf-sip-hop-limit-diagnostics-03, draft-gurbani-sip-large-udp-response-00 Noted that ongoing NIT work proposes to deprecate provisional responses for non-INVITE transaction. Proposed that SIP Redirection could be used to eliminate problem. Author will bring discussion questions to the mailing list. Topic: UA Profile Delivery led by Dan Petrie Slides included in proceedings Read: draft-ietf-sip-xcap-config-00 draft-petrie-sip-event-param-err-00 Changes since last version reviewed. Noted that OMA has a dependency on XCAP change notifications. To:do; OMA liaison manager to open a dialog on this dependency. Noted that PacketCable 2.0 uses this draft. Topic: Route Constuction Led by Jonathan Rosenberg Slides included in proceedings Read: draft-rosenberg-sip-route-construct-02 Noted that input from IMS vendors is needed to evaluate impact of this proposal. One speaker with some background in IMS opined that this technique should be useful with IMS. Issue: Is Service-Route a reasonable way to provide the outbound proxy set? One speaker didn't think so, but no alternative suggestions were noted. Further discussion deferred to mailing list. Meeting adjourned several minutes past scheduled end of session.