Minutes for CUSS at IETF-interim-2010-cuss-1
minutes-interim-2010-cuss-1-00

IETF CUSS WG Virtual Meeting II
Tuesday, Dec 21, 2010
9:00 AM - 10:20 AM CHICAGO

Note takers: Enrico Marocco and Leon Portman
Attendees on WebEx:
Vijay Gurbani
Enrico Marocco
Laura Liess
Alan Johnston
John Elwell
Andrew Hutton
Jerry Robinson
Keith Drage
Leon Portman
Paul Kyzivat
Frank Williams
Frederique Forestier

Agenda bashed, no changes.
Slides: http://www.standardstrack.com/ietf/cuss/cuss-interim-2/agenda.pdf

Problem statement and requirements, Alan Johnston
Slides:

http://www.standardstrack.com/ietf/cuss/cuss-interim-2/pres-cuss-reqs-01.pdf
Internet-Draft:
http://datatracker.ietf.org/doc/draft-ietf-cuss-sip-uui-reqs/
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Went through substantive changes in the current version of the document.
The following records the specific slides where discussion occurred.
An absence of a slide discussing requirements implies that the
meeting participants did not have any comments on it.

Slide 4: Keith stated that REQ-13 and REQ-14 may not be supported over
PSTN. Alan to clarify this in the next revision by stating that these
requirements are only pertinent when used between two SIP UAs.

Slide 6: REQ-3 changed to include UUI insertion and retrieval in referrals.
Keith noted that in ISDN, insertion by intermediaries is not supported
and that the UUI is inserted and consumed by endpoints. Alan agreed to
clarify in next revision.

Slide 7: Proposed change involved changing "dialog" to a "call". Discussion
ensued on what exactly the definition of a "call" is. If it is an
association between two endpoints, then a SUBS request will satisfy that
requirement as well. Alan will clarify by replacing "call" with text that
states the UUI will go only in INVITE, 2xx and BYE.

Slide 9: There was much discussion on slide 9, the result of which was
the following: Alan will propose a new requirement for carrying multiple
UUIs that can be distinguished (i.e., when they were inserted). In
addition,
REQ-3 will be clarified.

Slide 10: Discussions ensued, but no changes were proposed to the
requirement. However, there was an understanding that authentication
needs to be further discussed in the mechanism draft, especially in cases
where redirection is done in trusted domains.

Slide 11: Discussion ensued about the response growing bigger if multiple
UUIs are inserted in a response to the point that the response cannot
be sent over UDP (and conversely, cannot use TCP since the request came
over UDP). Option tags are a way to mitigate this. Alan agreed to add
some text in the mechanism draft discussing UUI in response.

Slide 12: Discussion ensued on discovery aspects of UUI (i.e., REQ-10
through the use of OPTIONS). A decision was made that UUI does not
apply to OPTIONS.

Next steps from the chair's perspective: The document is scheduled to go
to IESG in Dec-2010. If Alan can revise the document and there is list
consensus that the revision satisfies the WG, then a WGLC can be scheduled.
If the revised document raises other concerns, it may be best to deal
with these concerns by getting related parties on a conference bridge
and present the outcome of the discussions to the WG and produce a
revision that can subsequently be WGLC'd.

UUI Mechanism, Alan Johnston
Slides:

http://www.standardstrack.com/ietf/cuss/cuss-interim-2/pres-ccus-mech-01.pdf
Internet-Draft: http://tools.ietf.org/html/draft-johnston-cuss-sip-uui-01
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Went through substantive changes in current version of the document.

Slide 7 triggered a discussion on the specific mechanism that the WG should
come up with. Question asked of chairs on selecting a solution. The chairs
polled the meeting participants on whether anyone had an objection to going
with the header field approach. No one had any objections. A decision was
made to ratify the header approach on the list. Chairs will send an email
on the list asking for ratification.

Closing remarks, Vijay K. Gurbani (as chair)
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Currently, we do not see a need for a f2f meeting in Prague.
To move the work forward quickly, we can facilitate conference calls among
the key motivators of the work and fill the WG in with the results of
these conference calls. If there is a need to have a third virtual meeting,
we can do so before Prague. There is one more draft to be adopted --- the
Interworking ISDN call control draft --- after we have reached consensus
on the mechanism draft. Keith noted that we need to have a mechanism draft
to drive useful work forward.

Meeting adjourned at 10:20 AM CHICAGO TIME.