Internal WG Review: Centralized Conferencing(xcon)

[iesg-secretary@ietf.org]

A new IETF working group is being considered in the
Transport Area. The draft charter for this working group is
provided below for your review and comment.

Review time is one week.

The IETF Secretariat


Centralized Conferencing (xcon)
---------------------------------

 Charter
 Last Modified: 2003-08-04

 Current Status: Proposed Working Group


 CHAIRS: Alan Johnston (alan.johnston@mci.com)
                 Adam Roach (adam@dynamicsoft.com)

 Mailing list: <http://www.softarmor.com/mailman/listinfo/xcon>
 List-Archive: <http://www.softarmor.com/pipermail/xcon>

 Transport Area

 Responsible Area Director: Allison Mankin

 Description of Working Group

 The focus of this working group is to develop a standardized suite of 
 protocols for tightly-coupled multimedia conferences, where strong security 
 and authorization requirements are integral to the solution. 
 Tightly-coupled conferences have a central point of control and 
 authorization so they can enforce specific media and membership 
 relationships, and provide an accurate roster of participants. The media 
 mixing or combining function of a tightly-coupled conference need not be 
 performed centrally, however.

 The scope of this effort is intentionally more narrow than previous 
 attempts to standardize conferencing (e.g. centralized control), and is 
 intended to enable interoperability in a commercial environment which 
 already has a number of non-standard implementations using some of the 
 protocols.

 Privacy, security, and authorization mechanisms are integral to the 
 solution generated by the working group. This includes allowing 
 participants to be completely invisible or to be visible but participate 
 anonymously with respect to some or all of the other participants. 
 Authorization rules allow for participants and non-participants to have 
 roles (ex: speaker, moderator, owner), and to be otherwise authorized to 
 perform membership and media manipulation for or on behalf of other 
 participants. In order to preserve these properties, the protocols used 
 will require implementation of channel security and authentication services.

 Initially this combination of protocols will be specified with respect to 
 session setup with SIP. The solutions developed in XCON will not preclude 
 operation with other signaling protocols; however it is anticipated that 
 the use of other protocols would require modifications which are out of 
 scope for this working group.

 None of the protocols defined by this group will be SIP, although the SIP 
 specific event notification framework will be used. The group will use the 
 high-level requirements and framework already described by documents 
 published by the SIPPING WG.

 The deliverables for the group will be:
 - - A mechanism for membership and authorization control
 - - A mechanism to manipulate and describe media "mixing" or "topology" for 
 multiple media types (audio, video, text)
 - - A mechanism for notification of conference related events/changes (for 
 example a floor change)
 - - A basic floor control protocol

 The initial set of protocols will be developed for use in unicast media 
 conferences. The working group will perform a second round of work to 
 enhance the set of protocols as necessary for use with multicast media 
 after their initial publication.

 The following items are specifically out-of-scope:
 - - Voting
 - - Fully distributed conferences
 - - Loosely-coupled conferences (no central point of control)
 - - Far-end device control
 - - Protocol used between the conference controller and the mixer(s)
 - - Capabilities negotiation of the mixer(s)
 - - Master-slave cascaded conferences

 The working group will coordinate closely with the SIPPING and MMUSIC 
 working groups. In addition the working group will cooperate with other 
 groups as needed, including SIP, AVT, and the W3C SMIL working groups.
 In addition, the working group will consider a number of existing drafts (a 
 non-exhaustive list is included below) as input to the working group.

 Proposed Milestones

 Oct 2003 Submit Requirements for Membership Manipulation for publication as 
 Informational
 Oct 2003 Submit Requirements for Basic Floor Control for publication as 
 Informational
 Nov 2003 Submit Conferencing Scenarios document for publication as 
 Informational
 Nov 2003 Submit Use Cases for Media Topology Control for publication as 
 Informational
 Dec 2003 Submit Requirements for Media Topology Control for publication as 
 Informational
 Feb 2004 Submit Basic Floor Control Protocol for publication as PS
 Mar 2004 Submit Notification Event package extension for conference related 
 events for publication as PS
 May 2004 Submit Membership Manipulation Protocol for publication as PS
 Jul 2004 Submit Protocol for Media Topology Control for publication as PS