A new IETF working group has been proposed in the Transport Area. The IESG has not made any determination as yet. The following description was submitted, and is provided for informational purposes only: Centralized Conferencing (xcon) --------------------------------------------------- Current Status: Proposed Working Group 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 as input to the working group.