SIP Working Group Notes - Nov 10 13:00 Reported by Scott Lawrence Rohan - HEY - WE'RE STARTING Agenda Bashing - some order and emphasis changes from the chair. Rohan Mahy - Connection Reuse Rohan has received a number of mutually conflicting suggestions on how to address problems. Since a quorum of those making the suggestions are not available here now, it will be taken to the list. Cullen Jennings - what is the timetable to resolve them? RM - will do work with the goal of completing it before the next IETF. Jonathan Rosenberg - GRUU Two issues from the list. - Indicating whether or not there should be a URI parameter that labels it as a GRUU Clarify that the 'Supported: gruu' is not that indication. Sidebar: Retargeting Retargeting is a change to the target resource Routing is a change in the destination in order to reach the target resource 305 is defined as taking the Contact from the response and recursing with that contact in a Route header. all other 3xx change the target URI (as now) Proposal to change handling of message routing to use Route headers (see slides). This would clarify the distinction between Routing and Redirection as defined above, and use just one mechanism for each. Back to GRUU The change above helps solve the problem of interactions between Edge Proxy usage and GRUU. Rohan - this breaks outbound because... (JR agrees) Cullen - the original ER spiral was caused by the GRUU being allocated in the home domain rather than the visited domain. Why not solve it by getting the GRUU from the right place in the first place. Shawn Olson - if you put the GRUU in the route header rather than the contact (JR - need to see a concrete proposal to understand) Rohan Mahy - wrt deployment & implementation the common case where a UA registered for GRUU causes the flow to be locked to a particular edge proxy. (note taker is not following well enough to record) [consensus was that further work is needed - an attempt to schedule work will be made at the end of the meeting] Keith requested that there be a discusion document that lays out the alternatives and issues - JR agreed that is needed. Cullen Jennings - outbound config framework requires a subscribe before there is a gruu (because the UA does not have its credentials yet) UA should resubscribe once it gets credentials. (see slide for pin-route option tag - no discussion) Record-Route and Reliablity (no functional change from today) no discussion Service Route draft is incorrect - this is really a non-issue each registration returns a possibly different service route Discussion about how Service Route interacts badly with this. Paul K - what happens when you send a register request with no contacts - what service route do you get? JR - you should not get any SR in that response Agreed - there are changes needed to SR. Disagreement about whether or not there should be a dependency in this draft on those changes and/or the GRUU-motivated changes JR presented? Terminology The flow/flow-id/connection terminology terms are confusing Suggestions are solicited. Brian Rosen (no slides) There is a location conveyance draft - you need to read it because there are things being written that depend on it and we need to progress it. If there are people who support having a separate package for location conveyance please speak up on the list. James Polk - please copy the authors on any comments. Orit Levin - Refer Feature Parameters (see slides) Cullen - someone needs to write a document that lists all the tags and specifies which should be put where and when. The draft under discussion should normatively depends on that document. Paul K - more guidance is needed. Rohan - the current ambiguity is ok and this document should go forward Chair declares rough consensus that this should proceed as is. Jonathan Rosenberg - Target Dialog will revise and resubmit. Cullen Jennings & Robert Sparks: Note to that 3261 already recommends the use of crypto-random tag values. Existing implementations do not use enough bits to have sufficient randomness. Jonathan Rosenberg - Route Construction propose that the WG adopt a work item to clarify the ambiguities Support from several participants for getting clarification. Jon - as AD - this would be appropriate as a SIP WG document. WG Chair declares consensus and will request an additional chartered task from ADs. Dale Worley - Dialog Event Package Implementation Guidelines question re recommendations on how to authorize subscribe Cullen Jennings - there is an ambiguity with respect to how to signal state at the end of a call - is this addressed? Dale - no, but please send a note - it would be a good addition.