Minutes of the SIPPING WG Session at IETF 73
=================================================
Meeting chaired by Mary Barnes and Gonzalo Camarillo
Minutes edited by Mary Barnes
Based on detailed notes by Bruce Lowekamp and Spencer Dawkins
Detailed notes available on softarmor:
http://www.softarmor.com/sipping/meets/ietf73/notes/index.html
Jabber: http://www3.ietf.org/meetings/ietf-logs/sipping/
Jabber scribe: Dan York
Slides presented included in the proceedings.
Friday, November 21, 2008
--------------------------------------------
Summary of action items/way forward:
------------------------------------
- WG charter. Mary to post proposed charter updates to mailing list. Once agreed, forward to AD (Jon P) for approval. Mary to update WG s/s with new dates and post status to WG mailing list.
- draft-ietf-sipping-update-pai-07.txt: Three week WG re-review post IETF-73, ending Dec 15, 2008.
- draft-ietf-sipping-overload-design-00.txt: Volker to submit updated document. Once available (targeted for mid December) WG review to determine readiness for WGLC to be scheduled. Ideally, folks will forward this doc to their systems engineers for feedback and validation of the model, as well as gathering input from developers for the proposed solution (which will be progressed in SIP WG). Also, WG to be asked on the list as to where the simulation results should be captured - in this doc, a separate doc or not in any IETF doc.
- draft-ietf-sipping-profile-datasets-02.txt: Document to be revised by new editor (Dale Worley). Once available WG review to determine readiness for WGLC to be scheduled (targeted for mid January 2009). It is critical to get WG interest in and reviews for this document, due to other doc dependencies (on this document).
- draft-ietf-sipping-offer-answer-09: Solution proposals to be discussed on SIPPING WG mailing list. Once agreed, solutions will be progressed in SIP WG(pending SIP WG agreement to accept as work items). This SIPPING WG document will be updated to capture solution decisions so that BCP is complete.
- draft-niemi-event-throttle-07: Update to be submitted. Once submitted, WG initial review to commence to determine readiness to accept as WG document and WGLC (pending discussions with ADs). Doc can be completed in SIPPING WG
Note: this doc is a dependency for GEOPRIV work, as well as OMA.
- draft-loreto-sipping-context-id-requirements-01.txt: Discussion on this topic
to continue on the list.
- draft-johnston-sipping-cc-uui-04.txt: Authors to update the document and once available 3 week WG initial review to determine readiness for WGLC. Review ends on Dec 22, 2008. Once WGLC completed, doc will be forwarded to SIP WG for completion of solution (pending SIP WG agreement to accept as a WG item).
- draft-niccolini-sipping-siphandover-05.txt: Discussion on this topic to continue on the list.
- draft-dawes-sipping-debug-event-01 and draft-dawes-sipping-debug-id-01:
Discussion of a more general solution for SIP to continue to be discussed on SIPPING WG mailing list amongst interested parties.
Agenda item highlights:
=======================
Topic: Agenda Bash
------------------
Discussions led by: Chairs
Note: both chairs had computer problems at the beginning of the session, for which we apologize, Robert Sparks was gracious enough to drive the charts during the session.
The chairs presented the current status of the WG and the next planned charter updates, reflecting that the WG is behind in meeting milestones. We could improve by authors updating docs based on past mailing list (ML) and meeting discussions within a few weeks of the previous meeting, rather than just before the current meeting. Also, note that the majority of the topics for IETF-73 were the same ones discussed at IETF-72, reflecting the slow progress. However, progression of documents that had been progressed has been exceptional over the past few months: 7 new RFCs published, 2 docs moved to the RFC editor's Q and one document being Pub Requested.
The status of the documents which are dependencies for other SDOs was highlighted. All the OMA documents are progressing well. Some of the 3GPP documents have stalled and others are progressing very slowly (e.g., service identification - short term). Post IETF-73 Note: in particular it is suggested for folks to provide feedback on draft-saklikar-comm-diversion-notification-00.txt, which is a new 3GPP dependency to support Call Diversion notifications.
In addition, a couple of charts were presented, highlighting a prototype activity/architecture for Lawful Intercept: draft-yang-sipping-voipl-00.txt. A concern was raised that IETF had previously decided LI was out of scope for IETF. Although, an individual, RFC editor sponsored document had been published. Thus, from an outside perspective, the IETF position is not entirely clear.
It was suggested that folks with concerns raise them on the ML, since the authors were planning on moving forward with their work - i.e., the general sentiment expressed in the room seemed to be that this work SHOULD NOT be progressed (in IETF).
It was noted that the mega interim meeting that had been proposed for Malta has
been cancelled.
Post IETF-73 note: offline discussions amongst chairs/AD
concluded as well that no interim meeting before IETF-73 will be held for SIP
or SIPPING.
Topic: Updates to Asserted Identity
-----------------------------------
Discussion led by: John Elwell
Relevant documents:
draft-ietf-sipping-update-pai-09.txt
John discussed the outstanding issues based on the post-IETF73/post-WGLC comments. Note, that there had been virtually no feedback on the proposals that John had put forth.
Three primary issues were discussed:
1. Removal of PAI in responses. There were concerns raised that folks are doing
this and thus RAI in responses should be supported, however, there are security
concerns.
2. Inclusion of Service URNs. Some folks believe it should be allowed, but not necessarily specified.
3. Disallowing PAI in specific messages such as ACK and CANCEL. In particular, it was expressed that since CANCEL is hop-by-hop the applicability is irrelevant.
Conclusion: WG to provide feedback on each of these points within the next few weeks.
Topic: Overload Design and modeling
------------------------------------
Discussion led by: Volker Hilt
Relevant documents:
draft-ietf-sipping-overload-design-01.txt
This is a new WG document describing design considerations and
models for overload control and is not a proposal for a solution.
The current document does not include simulation results and the WG needs to
determine the best place to document those:
a) in this document (or appendix of this document)
b) in a separate document
c) in a non-IETF document (many of the results are published in journals, etc.)
This question will be asked on the WG mailing list when the updated doc is submitted for pre-WGLC review.
Ideally, folks will forward this doc to their systems engineers for feedback and validation of the model, as well as gathering input from developers for the proposed solution, which would be progressed in SIP WG.
Conclusion: Volker to submit updated document. Once available (targeted for mid-December) WG review to determine readiness for WGLC to be scheduled.
Topic: User Agent Profile Datasets
----------------------------------
Discussion led by: Martin Dolly
Relevant documents:
draft-ietf-sipping-profile-datasets-02.txt
Note: an IPR disclosure has been filed against this document:
https://datatracker.ietf.org/ipr/1031/
The primary changes were the removal of the application-profile and clarification that the merging algorithms are normative.
The schema of the document needs expert review (Mary has an action to find one).
This doc must be aggressively updated and reviewed so that we can target completion early 2009 due to the number of other documents for which this document is a dependency.
Conclusion: Document will be updated by new editor (Dale) and then a pre-WGLC
review to be scheduled.
Topic: Offer/Answer solutions
-----------------------------
Discussion led by: Christer Holmberg
Relevant documents:
draft-ietf-sipping-offer-answer-09.txt
(Note: doc has been "Publication Requested")
Christer proposed solutions for the outstanding problems identified in section
6 of this document.
At this time, the solutions are anticipated to impact RFC 3262 (likely in the form of a "bis"). It was mentioned that RFC 3261 may also be impacted. The potential for interop problems with some of the proposed solutions was discussed (e.g., removal of "First reliable response must contain SDP offer if INVITE does not").
The plan is that once solutions are agreed, they will be progressed in SIP WG, pending SIP WG agreement to accept as work items. This SIPPING WG document will be updated to capture solution decisions so that the BCP is complete.
Conclusion: Paul and Christer to start discussion of solution proposals on SIPPING WG mailing list.
Topic: Event Throttle
-----------------------
Discussion led by: Krisztian Kiss
Relevant document:
draft-niemi-event-throttle-07
This document provides additional event header field parameters (throttle, force and average) with which the rate of event notifications can be controlled.
The notifier can adjust the parms and they can be changed dynamically.
The way forward was suggested that once an updated version is available, the WG
will perform an initial review to determine readiness to accept as WG document and WGLC (pending discussions with ADs). Brian Rosen volunteered to serve as a reviewer.
Doc can be completed in SIPPING WG Note: this doc is a dependency for GEOPRIV work, as well as OMA.
Conclusion: Update to be submitted by editor. Once submitted, an initial WG review to commence to determine readiness to accept as WG document and WGLC (pending discussions with ADs).
Note: Mary will add this doc to SIPPING WG s/s to track reviews, status, etc.
Topic: SIP Context-ID requirements
----------------------------------
Discussion led by: Salvatore Loreto
Relevant documents:
draft-loreto-sipping-context-id-requirements-01.txt
The objective of this document was clarified as providing the capability to accomodate distributed user agent (clients). Alot of use cases have been removed from the current version of the doc, as well as solution text.
An initial question was raised as to whether the correlation of dialogs
is needed on session establishment or sometime later. The response was that there is no specific requirement as to when the correlation must start. It was also clarified that this also applies to across B2BUAs.
The general discussion was around whether there is interest in providing a
solution to correlate different dialogs.
Concerns were raised that the requirements are not quite clear and tend to be
more mechanism. As well, it was not clear as to whether this was correlation of
signaling and/or media.
It was noted that there are many different use cases and the semantics of those
need to be determined in order to develop a solution (for correlation).
Conclusion: Discussion on this topic to continue on the list.
Topic: Transporting User to User Information for SIP Call Control
------------------------------------------------------------------
Discussion led by: Alan Johnston
Relevant Document: draft-johnston-sipping-cc-uui-04.txt
The draft has been updated to include specific requirements. A query as to
the level of satisfication with the requirements indicated that there are
no concerns.
It was proposed that SIPPING WG review the document in terms of the problem
statement and requirements. A hum vote indicated that the WG is interested in
working on this problem and that the WG will agree on the requirements and then
hand the work to the SIP WG to complete the solution.
Conclusion: Authors to update the document and once available 3 week WG initial review to determine readiness for WGLC. Review ends on Dec 22, 2008.
Topic: Requirements for vertical handover of multimedia sessions using SIP
--------------------------------------------------------------------------
Discussion led by: Jan Seedorf (for Saverio Niccolini)
Relevant Document: draft-niccolini-sipping-siphandover-04.txt
It was highlighted that this document is dealing with terminal mobility and not
session mobility - the use case in this document is someone moving from one
terminal device to another.
It was proposed to form a design team to work on this problem before IETF-74.
There are a few people in the WG that are interested in this problem, although
some folks cannot commit resources to the effort at this time. It was
suggested that it is important for this work to consider working with 3GPP.
Conclusion: Discussion on this topic to continue on the list. Folks interested
in working on the problem, please contact the authors.
Topic: Debugging SIP
--------------------
Discussion led by: Kar Ann Chew
Relevant Document: draft-dawes-sipping-debug-event-01 and draft-dawes-sipping-debug-id-01
Note: an IPR disclosure has been filed against these documents:
https://datatracker.ietf.org/ipr/1030/
The focus of these documents is that debugging should be part of the network
fabric. The current docs focus on 3GPP - they are currently a 3GPP dependency that SIPPING WG chairs learned about just a couple weeks prior to IETF-73.
In general, folks believe there is a need for debugging for SIP networks,
however, it was suggested that using the SIP protocol to debug SIP might not
be the best choice.
A concern was also raised in that the security aspects of this solution proposal
are not addressed at all (blank security section).
If folks would like to work on this general problem we need lots of discussion
on the mailing list. There seemed to be lots of interest during the SIPPING WG
session and we need to continue that level of interest on the mailing list.
Conclusion: Discussion of a more general solution for SIP debugging to
be discussed on SIPPING WG mailing list amongst interested parties
(of which there seemed to be quite a few).