Minutes, SIPPING WG, IETF 57
----------------------------------------
----------------------------------------
Notes by Tom Taylor, AC Mahendran, and Hisham Khartabil
Minutes edited by Dean Willis
Chat room moderation by Brian Rosen
Meetings chaired by Gonzalo Camarillo, Rohan Mahy, Dean Willis
Session 1, July 14, 2003 1930-2200
==================================
Topic: Agenda
---------------------
Agenda accepted as previously posted.
Topic: Announcements and Status
----------------------------------
Chairs mentoin the SIP device reqts ad hoc 10-11 am Thur room J241/1, and
that the QoS promotion scheme draft will be discussed in Friday's TSVWG
meeting.
Slides presented reviewing status of working group documents.
pres-chairs-SIPPING-WG-status-ietf-57.ppt
Topic: SIP to QSIG Mapping
------------------------------
Relevant document:
draft-ietf-sipping-qsig2sip
Slides presented
pres-elwell-qsig2sip-ietf-57.ppt
Discussion led by John Elwell
Issue: We need more qualified reviewers for this work. A hand-poll taken in
the room indicated about a dozen people claiming to be familar with QSIG. We
discussed possibly working with external SDOs on this. Discussion
indicated that ECMA is the likely SDO. John Elwell took the action item of
providing a list of ECMA contacts to Allison Mankin.
No conclusion.
Actions: Francois Audet to formally review document.
Topic: Dialog Package
-----------------------
Relevant document:
draft-ietf-sipping-dialog-package
Slides presented:
pres-rosenberg-dialog-pkg-ietf-57.ppt
Discussion led by Jonathan Rosenberg
Status: Went through WGLC. Minor comments incorporated. Unable to
restrict a particular XML type in XML -- has only the accompanying text to
provide the constraint.
Issue: extensions proposed (Sean Olson). Question: what to do with them?
Extend scope of main package, reject them, or document them
separately?
Issue: "on hold". Not clear what "on hold" means, since media can flow
anyway. Suggestion that this isn't a dialog state.
Conclusion: Rough consensus that we are not ready to advance the dialog
package at the present time. Concerned parties instructed to discuss and
report back to Thursday mtg.
Topic: Discussion of Configuration Issues
------------------------------------------
Relevant documents:
draft-ietf-sipping-config-framework
draft-ietf-sipping-ua-prof-framewk-reqs
draft-ietf-simple-xcap-package
Slides presented:
pres-petrie-config-fw-issues-ietf-57.ppt
pres-mahy-config-issues-ietf-57.ppt
Some open issues w/ profiles. No discussion. No conclusion on
framrework or profiles.
Issue: potential conflict between XCAP package (SIMPLE work item) and
sip-config. XCAP fits into framework: config retrieval, change notif,
config upload. Differences in many details. Do they share the same
requirements? Do they share the same solution? Should they be
unified?
Proposal to unify led to comment that config is a much more general
problem -- it may not be reasonable to use SIP for notifications in view of a
more general model coming perhaps out of netconf. This may reflect the
views of a number of people in the IETF at large. We will need to have a
clear explanation of scope.
Key point: all of the entities involved have SIP addrs. Fairly tightly
scoped.
Proposal: merge or reorg the two drafts. Need an author w/more cycles.
Poll indicated rough consensus in favour, with some hums opposed. Locus of
work to be discussed w/ ADs, noting two different areas are involved.
Conclusion: Chairs to discuss with ADs.
Topic: Session Policy and Middle Box Issues
----------------------------------------------
Relevant Document:
draft-ietf-sipping-session-policy-req-00.txt
Discussion led by Jonathan Rosenberg
Issue: Dynamic vs static policies
-- Allison: not necessarily either/or
-- Jonathan just concerned to eliminate unnecessary reqts
-- CALEA an arg against dynamic policies
Rohan volunteers to work on mechanism if he has some help.
Questions on reqt for enforcement of policy. Audience asked to review text
and submit desired changes.
No conclusion.
Editors note: 3GPP is expecting some results here.
Topic: URI Leasing and GRUUS
----------------------------------
Relevant document:
draft-rosenberg-sipping-lease-00.txt
An informal group met prior to this meeting. They noted that embedded
route headers prevent proxy application of policy and user services, and
that leasing has a couple of other advantages. This groups
conclusion is that leasing seems to be the way to go. There appear to be
some open issues wrt GRUU grants. The author will add requirement that
leasing be stateless to the requirements doc.
Conclusion: Agreed that requirements shall address stateless leasing.
Consensus that work will continue with leasing model at this time.
Topic: Firewall and NAT Traversal
------------------------------------
Relevant Document:
draft-rosenberg-sipping-ice-00.txt
Slides presented in:
pres-rosenberg-sipping-nat-stuff-ietf-57.ppt
Status report
ice-01 addresses concerns raised in IETF 56
-- backward compatibility
--- case that breaks bkwd compatibility is multihomed host. alt
framework vs. alt attribute being taken into off-line discussion
ice-01 has ~50 pages of example flows -- proposed replacement of
sipping-nat-scenarios
-- ice algorithm works out
-- troublesome case is v4-v6
-- need add call flow between ice and non-ice hosts
Question from chair: if Jonathan adds the required cases, is this a
sufficient replacement for what we have now in the
sipping-nat-scenarios document? Consensus is that it is adequate,
provided that we add text to allow alternate approaches (such as ALG,
MIDCOM) and add cases for MSRP relay. Francois Audet volunteered to send
text relating to alternate approaches.
Process open issues:
1. Do we proceed, and if so, in which WG?
-- main ice behaviour -- mmusic?
-- SDP extensions -- mmusic
-- preconditions -- if people care, would go to sip (poss mmusic)
-- usage scenarios -- repl sipping-nat-scenarios -- sipping
Conclusion: Hums indicated a consensus to do core ICE behavior and SDP
changes in MMUSIC, usage scenarios in SIPPING, and preconditions work in SIP
if needed.
Chairs are to discuss division of work with ADs.
Topic: Adding Realm Identifier for Private Addresses
------------------------------------------------------
Relevant Document:
draft-audet-sipping-add-realm-00.txt
Slides presented in:
pres-audet-sipping-add-realm-ietf-57.ppt
Notes: Adds explicit realm identifier for private (i.e. "local")
addresses into SDP. Useful in case both endpoints have a priori
knowledge that they are in the same
realm -- can avoid ICE. Need to configure realm only if multiple media
terminations behind the same NAT which will communicate with each other.
Proposes SDP attribute. Configuration mech out of scope of current
draft.
Discussion on network toplogy and applicability indicated that some
additional clarity is needed. How does this relate to
phone-context?
Conclusion: Requires further list dicussion. Burden of proof is on
Francois to say it is worth varying from general application of ICE.
Topic: Open Issues from Conferencing Design Team
-----------------------------------------------------
Relevant documents:
draft-ietf-sipping-conferencing-framework
draft-ietf-sipping-cc-conferencing SIP
draft-ietf-sipping-conferencing-requirements
Slides presented in:
pres-levin-conf team-update-ietf-57.ppt
Discussion led by Orit Levin
Status: Conceptual issues resolved: basic conf by SIP, adv would use XCON
(they hope). Design team work is almost complete and they welcome
general comments. If XCON forms a working group, it may be possible to
reduce the scope of
draft-ietf-sipping-conferencing-requirements to "just the SIP
requirements."
Open issues with
draft-ietf-sipping-conferencing-requirements: Focus discovery.
Open issues with
draft-ietf-sipping-cc-conferncing: add details for selected msgs in
presented call flows, or move into sip draft for mechanisms.
Open issues with
draft-ietf-sipping-conference-package: Needs another rev e.g. re sidebar
conversations Looking to future draft on implementation of sidebar
Topic: Open Issues from Transcoding/Deaf Design Team
---------------------------------------------------------
Relevant Document:
draft-camarillo-sip-deaf-02.txt
Slides presented in:
pres-camarillo-transcoding-emergency.ppt
Discussion led by Gonzalo Camarillo.
Status: Resuming design team meetings. Transcoding has dependencies which
may be isolated in a separate draft.
No conclusion.
Topic: Report from Energency Calling Design Team
----------------------------------------------------
Slides presented in:
pres-camarillo-transcoding-emergency.ppt
Discussion led by Gonzalo Camarillo
Status: Scenarios doc to appear within a couple of weeks.
Topic: Requirements for SIP Service Configuration
---------------------------------------------------
Note: This has some bearing on 3GPP's use of SIP.
Proposal: Extend config framework to include service info.
Open issue: Which server to contact for data manipulation (XCAP)?
Open issue: Download conference-factory URI for automatic conf creation
No conclusion.
Session 2, Thursday, July 17, 2003, 1300-1500
=====================================
Topic: Agenda and Status
----------------------------------
Review requested for new digest-AKA draft.
Topic: Open Issues from Application Interaction Design Team
----------------------------------------
-----------------------
Relevant Documents:
draft-rosenberg-sipping-app-interaction-framework-00
draft-jennings-sip-app-info-01
draft-burger-sipping-kpml-02
Slides presented in:
pres-rosenberg-sipping-day2-ietf-57.ppt
Discussion led by Jonathan Rosenberg
Issues:
KPML DTMF reporting problem
- INFO ( Cannot work within call dialog)
- NOTIFY w implicit subscription
- Explicit subscription from application
- HTTP
- New method?
- MESSAGE
Design team reluctantly chose MESSAGE!
Proposal:
- Continue to hammer out the open issue
- Adopt the framework and KPML as SIPPING items.
Conclusions:
a) Hum on "This is interesting work and that we should adopt the
framework" - Accepted.
b) Hum on "All who believe KPML should be accepted as WI" - accepted.
c) Chairs will ask the AD to adopt framework and KPML as WG items.
d) The KPML reporting issue will be discussed more on the mailing list.
Topic: Early Media
-------------------
Relevant document:
draft-camarillo-sipping-early-media-02.txt
Discussion led by Gonzalo Camarillo
Status:
Changes since last rev include clarifying which features are specific to
early media and which ones to SIP and other editorial changes.
To be done: Align application server model section with app design team
No conclusions.
Topic: Conveying Tones in SIP
-------------------------------
Relevant document:
draft-mahy-sipping-tones-00.txt
Discussion led by Rohan Mahy
Issue: How to provide tones?
Options discussed include
1) In RTP
a. Speech codec - poor choice
b. Using audio/tone AVT payload
c. Using audio/telephone-event AVT payload
2) Referenced externally by URI with Alert-info or
message/external
3) In a SIP header (proposed back in Nov 2000)
4) In the session description
5) In SIP body
a. Use Content-Disposition: Render
If in a body, What body types are available?
1) Traditional
a. Wav, au, mp3
2) Audio/tone
3) Audio/tone-info+xml
4) Many more..
5) XML based: Audio/tone-info+xml
Discussions:
-Use of midi was suggested by Henning.
Conclusions: The issue on tones will be discussed more on the list.
Topic: Network Announcements
---------------------------------
Relevant document:
draft-burger-sipping-netann-06
Discussion led by Eric Burger.
Open Issues:
1) Early media:
Punt. No definitions for early media
Makes 487/409 problem go away.
2) Media on hold
Punt. Local matter
3) Multiple media streams
Punt. Netann is about objects not streams
Only composite objects for multimedia
4) VoiceXML keyword without value
Generate 404 with explanation.
Poll taken for adoption as a working group item indicated little
support. However, the work is not seen as being in opposition to
chartered work.
Conclusions: The draft will be submitted for publication as an
individual contribution.
Topic: Event Filtering and Throttling
------------------------------------
Relevant document:
draft-niemi-sipping-event-throttle-reqs-01.txt
Slides presnted in:
pres-niemi-event-throttle-ietf-57.ppt
pres-niemi-sipping-ietf57-throttles-17072003.ppt
Discussion led by Aki Niemi
Changes:
1) Updated model. A throttle defines minimum time period between two
notifications
2) Updated use cases
3) Refined requirements
4) Aligned language with model
Open issues:
1) Should use cases be more elaborate?
Proposal: No
2) Are Requirements are solid enough?
Seem to be.
3) Is scope for work well defined?
Seem to be.
Discussions:
- It was suggested that it would be worth noting in the draft about the
type of buffering needed (like LIFO, FIFO etc)
Conclusion: Chairs will recommended to the ADs to adopt this draft as WG
item.
Topic: DPNSS to SIP Interworking
------------------------------------
Relevant document:
draft-mukundan-sipping-dpnss-02.txt
Slides presented in:
pres-mukundan-sipping-dpnss-ietf-57.ppt
Discussion led by Ranjith Mukundan
Difference between DPNSS MIME and QSIG/ISUP MIME
1) Similar to RFC 3204 (MIME for ISUP/QSIG
2) Mandates single binary coded octet message length field
3) Specifies message buffering option
4) Mandates single DPNSS call per SIP dialog
Discussions:
- Henning indicated that this doesn’t work with the MIME model.
- Some were skeptical about the usefulness of doing this work.
- There was a feeling that the group did not have enough expertise to take on
this work.
- Gonzallo indicated that solving the MIME type is reasonable but the
translation work is a tough thing to do.
Conclusions: This will NOT be taken as WG item and it will proceed as an
individual contribution.
Topic: Discussion of End-to-Middle Security
---------------------------------------------
Relevant document:
draft-ono-sipping-end-middle-security-00.txt
Slides presented in:
pres-ono-end2middle-ietf-57.ppt
Discussion led by Kumiko Ono
Issues:
1) End-to-end encryption may conflict with some features provided by
intermediaries
2 )Use cases:
a. Logging services (IM logging, other logging)
b. Hotspot service
c. Connecting to home SIP server via partially trusted proxy
3) Session-policy
4) Transcoding
Proposed Mechanism:
- Allows a UA to disclose data to selected intermediaries
- End-to-middle encryption uses S/MIME CMS Enveloped data for
intermediaries.
Discussions:
- People felt that this is a very interesting WI.
- Jonathan R said that we need to add more use cases to explain the
problem of addressing data for intermediaries by user-agent.
Conclusions:
1) There was consensus in the room that work has enough interest in the
group.
2) There was consensus that the requirements on end-to-middle &
middle-to-end security should to be taken on as WG item.
Topic: Phone-related Status and Presence
------------------------------------------
Relevant document:
draft-rosenberg-peterson-simple-pidf-phone
Slides presented in:
pres-rosenberg-sipping-day2-ietf-57.ppt
Discussion led by Jonathan Rosenberg
Discussions:
-Difference between human presence vs device presence.
- Rohan said that states like dialing/ringing etc are not applicable to
device or user; these are particular to a call/dialog. Some of the raw data
is useful, but presence may not be right place for it.
- Henning: Information like line-state etc are not too useful as
presence information.
Conclusions:
a) Hum on "Dealing with presence issues of phone" as useful work
indicated a consensus..
b) Jonathan proposed to develop more use cases for the draft.
c) Is this a SIMPLE or SIPPING activity? Chairs to discuss with SIMPLE
chairs.
Topic: Session Diagnostics in SIP
----------------------------------
Relevant document:
draft-johnston-sipping-rtcp-summary-00.txt
Slides presented in:
pres-johnston-sipping-rtcp-summary-ietf57.ppt
Discussion led by Alan Johnston
Summary:
1) Delivery of RTCP summary reports to third parties
a. Logging is main motivation
2) Three alternatives
a. Forking RTCP to multiple locations
b. Carrying in SIP header in BYE
c. Event package (preferred)
Discussions:
1) Should RTCP be transferred to third parties?
2) What is the purpose of this? If this is for fault management or
performance management, this is not needed. SNMP management tools should be
sufficient.
3) How does this compare to RMON?
Conclusions: This will be deferred to this to the list. Alan is asked to
investigate RMON work and provide some comparison here.
ACTION ITEMS
-------------------
1) John Elwell volunteered to provide a list of ECMA contacts for QSIG to
SIP work o Allison Mankin.
2) Chairs to discuss netconf and XCAP reconciliation proposals with ADs.
3) Francois Audet volunteered to review the qsig2sip document and
respons on-list.
4) Francois Audet volunteered to send text relating to alternate
approaches such as ALG and MIDCOM for the ICE usage scenarios
document.
5) Chairs to discuss moving some ICE work into MMUSIC and SIP with ADs.
6) Chairs to discuss adding
draft-rosenberg-sipping-app-interaction-framework-00 and
draft-burger-sipping-kpml-02 as WG items with ADs.
7) Chairs to work withs AD to add charter item(s) for
end-to-middle and middle-to-end security requirements.
8) SIPPING chairs to discuss phone-presence with SIMPLE chairs and ADs to
dtermine where thiswork belongs.
9) Alan Johnston was asked to consider how RMON work relates to
proposed RTCP summary work and report to the mailing list.
|
