Minutes, SIPWG IETF57

Recorded by Alan Johnston (alan.johnston@mci.com)
Edited by Dean Willis (dean.willis@softarmor.com)
Revised 17Jul2003
Meeting July 16, 2003,  0900

Start
-------

Meeting called to order by chairs.
Proposed agenda reviewed and accepted.
Announcement: Jon Peterson has retired as SIP co-chair.
Brian Rosen volunteered as chat room moderator.
Alan Johnston volunteered as scribe.

Status of Drafts - Chairs
---------------------------------

New Pubs: RFC 3515 REFER published

MIB: Volunteers to review a section of MIB: Orit Levin, Mary Barnes, Cullen Jennings, and Kent (Rohan has his info). Rohan will assign some more volunteers.

congest-safe:  Proposal for author to remove UDP kludge.  No objections or discussion.



PUBLISH - Aki Niemi
------------------------------

Open Issue: collision recovery.  Proposed solution: query principle, may subscribe to package. No objections or discussion.

Open Issue: PUBLISH and dialogs.  Proposed solution: add text about dialogs, discourage reuse. No objections or discussion.

Open Issue: atomicity. Proposed solution: relax restriction about overlapping requests.

Comment: Go with a simpler model - all tuples are independent.  Solve using composition and authorization instead of publication.  Or, most recent publisher overrides any others.

Comment: Agree with comment. Don't reinvent Webdav.  Don't make endpoint behavior too complex. 

Comment: Agree with comment that this is an authorization problem.

Comment: Not clear we can relax overlap with congestion issues.

Conclusion: Author will take to the list for more discussion.


Resource Priority - Henning Schulzrinne
-------------------------------------------------------

Issue: error handling.  Proposed solution: 503 or 403 or 417 (Unknown Resource Priority - only if Require is used. No objections or discussion.

Believed to be ready for WGLC

Comment: Pointers to name spaces are in draft.

Comment: Role based authorization is still moving forward.

Volunteers to review the next draft: Paul Kyzivat, Ben Campbell

Caller Prefs - Jonathan Rosenberg
-----------------------------------------------

Issue in Callee Caps - URI-user and URI-domain - duplication: Suggested  Use a Device ID (Contact URI attribute) instead? No conclusion in this discussion.

Comment: Device ID is interesting, but could be overloaded. Should recommend GRUU for attended transfer.

Comment: Expiration of device ID is unpredictable.

Conclusion: Quick list consensus on adding device ID.  Recommend GRUU instead for transfer case.

Caller Prefs

Comment: Enumeration is better

Open Issue: redirection - RFC 3261 proxy merging q-values is broken.  Proposal: include text saying this.

Question: Do we need to mandate this?  Questioner will send a short use case to mailing list.

Open Issue: lost use cases due to changes.

Comment: This is a feature.

Comment: Can be done with multiple requests.

Conclusion: no changes needed.

Open Issues in Use Cases: No discussion.

Comment: Does basing on RFC 2533 provide any value?

Comment: Should RFC 2533 reference just be an informational reference?


SIP Identity - Jon Peterson
-------------------------------------

Topic: AIB

No issues or comments.

Topic: AES and S/MIME

Question: Should we redo S/MIME examples in RFC 3261?

Proposal: Cullen Jennings could do some examples. 

Comment: Base-64 encoding issue causes interoperability problems. (Binary encoding is better)

Comment: No commercial SIP stacks support S/MIME and TLS.

Comment: There were 2 implementations of S/MIME at last SIPit.


History Info - Mary Barnes
-------------------------------------

Open Issue: Index.  Proposal: Make it mandatory and clarify loose routing behavior.

Open Issue: Internal Retargeting.  Proposal: Include some normative text and examples.

Open Issue: Privacy.  Proposal: Add text.

Comment: Draft needs major clarification on privacy, redirection, backwards compatibility, others. Will discuss on list.

Comment: Include in security section - this header solves a useful problem that a requestor could verify that appropriate proxies have retargeted a request.

Conclusion: Much more work needed.

Securing SIP Identity Headers - Mary Barnes
--------------------------------------------------------------

(SIPPING draft but discussed here for convenience)

Comment: Question on question not solution.  Do we need to do this?

Comment: This is a type of middle-to-end security problem. We need to solve this problem.

Comment: If we redid Proxy-Auth header, we would use a body instead of a header.


Parameter Registry - Gonzalo Camarillo
--------------------------------------------------------


Open Issue: Which URI parameters should be registered?

Comment: Do we want p-parameters?

Comment: Lets not make the same mistake twice.

Comment: Want to increase interoperability and avoid collisions.

Comment: To prevent conflicts during Internet-Draft stage, should use this registry.

Comment: C language analogy -- this is like requiring C developers to go back to Standard C committee and register every variable name they use as a language keyword. The registry could be flooded with requests.  Propose that we should only register URI parameters that are global in nature.

Comment: Have informal non-IANA registry instead (webpage)

Comment: Should do the same thing for parameters (headers and URIs) as headers.

Comment: Similar to standardization of headers across protocols effort.

Conclusion:   A Hum was taken which supported the creation of an IANA registry for parameters defined by  RFCs. No consensus on the rest of the issue - more list discussion needed.


Connection Reuse - Rohan Mahy
---------------------------------------------

Open Issue: Clarity on which is original and which is alias.

Open Issue: Security - explaining Mutual TLS and digest

A Humm was taken which supported that people care about the work.

A Humm was taken which supported that this mechanism is reasonable.

Comment: Need to describe how to handle when multiple parties claim the same alias (10.1.1.1).

Conclusion: A Humm was taken which supported that the chairs request a charter modification to adopt as a WG item.


SIP Security and S/MIME - Cullen Jennings
------------------------------------------------------------

Comment: Mechanism could be used for certificate or raw keys.

Comment: Identity work avoided UAS having to do any PKI operation.  Identity document also only identifies the domain,
not the individual user.

Question: Does this work in both ways?  Answer: Yes, but not exactly.

Many more comments until we ran out of time.

Hum taken on interest of working group in solving this problem.  Strong interest indicated.

Conclusion: The WG will continue discussion of this topic.