Meeting: IETF-60 Work Group: XCON Date: 2-aug-2004 Time: 9:00 - 11:30am Scribe: Paul Kyzivat - Workgroup Status - Alan Johnston Discussion of whether to split CPCP into two docs. Hisham Khartabil expressed opinion that this split is unnecessary. A proposal was made to split the conference package responsibilities - roster in SIPPING, media and policy moved to XCON. This will permit wrapping up conference work in SIPPING. Jonathan Rosenberg raised concern that this be done carefully or there may be risk that the framework doesn't work fully. But he wasn't opposed to the split. Cullen Jennings thought it might be premature to finish the framework until the XCON work is further along. Some skepticism by others. There will be more discussion on this subject later. - Updates to the SIP Conferencing Package (draft-ietf-sipping-conference-package-05) Orit Levin Orit explained that she had made at media level as a strawhorse - she isn't confident in them yet and requested feedback. An issue raised by Jonathan Lennox that there is no way to remove a sidebar in a partial notify. Orit said there is intended to be, and agreed to investigate. Jonathan raised issue of whether sidebar should be defined in SIPPING or in XCON. It is currently unclear whether sidebars are a special type of conference or just a mixing policy. This might suggest delaying the completion of the SIPPING work until XCON is more advanced. Orit explained the newly added element of user-type, called user-status-type. Cullen Jennings objected - claiming this is really a session level info, not user level. Orit thought it would be up to focus to figure out how to set this if there are multiple sessions for a user. Jonathan thought two sessions could be represented as two users. Roni Even seemed to agree with Jonathan. Cullen prefered users to have (potentially multiple) sessions which in turn have media streams. Jonathan thought this may be an artifact of non-uniqueness of the uri, and explained a way to treat those as separate users. Alan Johnston asked for the SIPPING conference design team to get together this week and thrash out this issue. - Sidebars (draft-rosen-xcon-conf-sidebars-01) Alan Johnston Rohan Mahy said this document doesn't address case where user with single audio/video session wants audio in a sidebar but video to remain in the main conference. Alan thought it is possible, via CPCP but not SIP. He also thought this needs to work even when SIP isn't used - where there is only PSTN plus CPCP over HTTP. He wanted more examples of that. Alan agreed that this doc is SIP specific and perhaps doesn't need to be. Eric Burger wasn't happy with this direction - he thought it was just recreating H.245. He thought sidebars should be separate conferences, that you establish a new dialog to, that just happen to have media from the main conference. Rohan disagreed - claiming this has no advantages and imposes extra requirements on endpoints, while Eric thought this didn't require any uncommon behavior. Eric was requested to send text. Dave Oran asked if/how it is possible to have different keying for media in sidebar vs not - that this should be possible and may help determine the proper architecture. Brian Rosen asked (via IM) *why* you would want separate keying for a sidebar. Dave asserted the user expectation is for extra privacy in a sidebar. Rohan thought this is possible, but out of scope. But Alan and Dave felt this is in scope - that only multicast keying is out of scope. Alan agreed that expectations are there and should be met somehow. - Media Policy (draft-jennings-xcon-media-control-01) Cullen Jennings This was a status update by the design team. The team has investigated both Rohan's flow graph approach and the Jennings/Rosen template approach. They ecided to keep both approaches. They are currently working on a set of example templates, but aren't done yet, and request permission to continue work for another round. Dave Oran asked why an inheritance model is used for roles, vs a flat model - asserting that an inheritance model is more complex. Cullen agreed to investigate. - Conference Policy Control Protocol (CPCP) (draft-ietf-xcon-cpcp-xcap-01) Hisham Khartabil Hisham raised some issues in tying this work into the conferencing framework. Jonathan asserted this is a non-issue - that the framework can and should change to accomodate this work. Hisham agreed to send text for revising the framework. There was an extended discussion of identity and the role of pins and passwords in it. The policy syntax has list of conditions including and . Cullen argued that and should simply be alternative ways of authenticating, not a separate mechanism. Dave Oran didn't see clear distinction between what identity for authentication and identity displayed for the user. Rohan was concerned about what happens if someone admitted based on identity and pw, and then the rules are changed to remove or change the pw check. Is the user bumped then? Cullen thought the pin/pw stuff raises many issues that must be resolved. There was considerable further discussion on this subject, evidencing confusion about the semantics. Open Issues - problem interpretting the element. Do we need to say more about interpreting elements? Needs to tie to specific signaling protocols -- SIP and H.323? SIP and XMPP? Anything we have text for? There was a proposal to do for SIP, and allowing fill in for others. A question was raised whether a way is needed to permit subscription to conference state while restricting what can be received. Cullen asserted this can't be decided until we know what the conference state includes. There was also a question about the need for polite blocking. There were some comments that this is not needed, but no humm was taken. There were similar question about floor control events, and conference info events. Hisham proposed to leave as is unless someone complains. There was discussion of the newly proposed REFER list. After discussion it seemed people would probably agree if the intended usage was better explained. An issue was raised regarding media stream security policy - how to specify specific means of security without becoming media dependent. A proposal was made to simply specify that media must be secure and leave it to the focus to decide how. Some discussion of whether this is conference or media policy, or both. There was no clear decision on this point. [End of Session]