AC's Notes on SIPPING Session 2, IETF 57


SIPPING Session II, Thursday, July 17, 2003,  1300-1500

1) Agenda/Review:

Gonzalo Camarillo asked the group to review Digest-AKA and get back to the authors.

 2) Open Issues from Application Interaction Design Team

draft-rosenberg-sipping-app-interaction-framework-00
draft-jennings-sip-app-info-01
draft-burger-sipping-kpml-02
 
Presenter: Jonathan Rosenberg
 
Issues:
 
KPML DTMF reporting problem
·         INFO
    o 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.
 
3) Discussion of Media-related Issues
 
3a) Early media (draft-camarillo-sipping-early-media-02.txt):
 
Presenter: Gonzallo Camarillo
 
Changes:
·         Clarify 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
 
 
3b) Conveying Tones in SIP (draft-mahy-sipping-tones-00.txt)
 
Presenter: Rohan Mahy
 
·         How to provide tones?
o        In RTP
§         Speech codec – poor choice
§         Using audio/tone AVT payload
§         Using audio/telephone-event AVT payload
o        Referenced externally by URI with Alert-info or message/external
o        In a SIP header (proposed back in Nov 2000)
o        In the session description?
o        In SIP body
§         Content-Disposition: Render
 
What body types are available:
·         Traditional
o        Wav, au, mp3
·         Audio/tone
·         Audio/tone-info+xml
·         Many more…
 
XML based:
Audio/tone-info+xml
 
 
Discussions:
-Use of midi was suggested by Henning.
 
Conclusions:
a) The issue on tones will be discussed more on the list
 
3c) Network Announcements (draft-burger-sipping-netann-06)
 
Issues:
·         Early media
o        Punt. No definitions for early media
o        Makes 487/409 problem go away.
·         Media on hold
o        Punt. Local matter
·         Multiple media streams
o        Punt. Netann is about objects not streams
o        Only composite objects for multimedia
·         VoiceXML keyword without value
o        Generate 404 with explanation.
 
Discussions:
-No comments.
 
Conclusions:
a) The draft will be submitted for publication as an individual contribution.
 
 
4) Discussion of Event Filtering and Throttling (draft-niemi-sipping-event-throttle-reqs-01.txt)
 
Presenter: Aki Niemi
       
Changes:
·         Updated model
o        A throttle defines minimum time period between two notifications
·         Updated use cases
·         Refined requirements
o        Aligned language with model
 
Open issues:
·         Should use cases be more elaborate
o        Proposal No
·         Requirements are solid enough
·         Scope for work is well defined
 
Next steps:
·    Move to WG item?
 
Discussions:
-        It was suggested that it would be worth noting in the draft about the type of buffering needed (like LIFO, FIFO etc)
 
Conclusions:
a) It will be recommended to the ADs to adopt this draft as WG item.
 
 
5) Discussion of DPNSS to SIP interworking (draft-mukundan-sipping-dpnss-02.txt)
       
Presenter: Ranjith Mukundan
 
Difference between DPNSS MIME and QSIG/ISUP MIME
·    Similar to RFC 3204 (MIME for ISUP/QSIG
·    Mandates single binary coded octet message length field
·    Specifies message buffering option
·    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:
a) This will NOT be taken as WG item and it will proceed as an individual contribution.
 
 
6) Discussion of End-to-middle Security (draft-ono-sipping-end-middle-security-00.txt)
 
Presenter: Kumiko Ono
 
·         End-to-end encryption may conflict with some features provided by intermediaries
·         Use cases:
o        Logging services (IM logging, other logging)
o        Hotspot service
§         Connecting to home SIP server via partially trusted proxy
o        Session-policy
o        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:
a) There was consensus in the room that work has enough interest in the group.
b) There was consensus that the requirements on end-to-middle & middle-to-end security should to be taken on as WG item.
 
 
7) Discussion on Phone-related Status and Presence (draft-rosenberg-peterson-simple-pidf-phone)
 
Presenter: Jonathan Rosenberg
 
What is it:
·         A set of presence states that describe a phone as an application
o        Considered black phones, wireless, enterprise
·         States are things like in/out of call, registered, call waiting
·         Looking for comments and inputs to this work.
 
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” - Accepted.
b) Jonathan proposed to develop more use cases for the draft.
c) Is this a SIMPLE or SIPPING activity?
 
 
8) Discussion of Diagnostics in SIP (draft-johnston-sipping-rtcp-summary-00.txt)
 
Presenter: Alan Johnston
         
 
Discussions:
- Should RTCP be transferred to third parties?
- Jonathan R: 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.
- Eric burger: This is definitely an SNMP kind of thing. Now we have SNMP over SIP; so, when will this stop?
 
Conclusions:
a) This will be deferred to this to the list.