CURRENT_MEETING_REPORT_

Reported by Ruth Lang/SRI International

Minutes of the Multiparty Multimedia Session Control Working Group
(MMUSIC)

An on-line copy of the minutes and the accompanying PostScript slides
are available from ftp://ftp.isi.edu/confctrl/minutes in the files
ietf.4.95 and slides.4.95.tar.

The Multiparty Multimedia Session Control Working Group (MMUSIC) met for
two sessions (one planned and one impromptu) on 5 April at the 32nd
IETF.


Revised Working Group Charter

Ruth Lang gave an overview of the revised working group charter
(slides.4.95.a).  The new charter provides a more balanced focus on the
range of conferencing styles, motivates the development of solutions for
loosely-controlled conferences, and encourages identification of
interoperability issues with related international/consortium standards
efforts.  New goals and milestones were reviewed.  No comments on the
revision were received during the meeting, but were requested to be sent
to the mailing list, confctrl@isi.edu.  The revised charter will be sent
for review by the Transport Area Director and subsequent submission to
the IESG in April.


The Agreement Protocol

Abel Weinrib presented an update on the Agreement Protocol.  A document
in Internet-Draft format describing the protocol was circulated to the
list.  After some formatting issues have been addressed, it will be
submitted as an Internet-Draft.  Ted Ko, who described his
implementation of the Agreement Protocol at the MMUSIC meeting during
the 31st IETF, has not made progress toward making this implementation
available, or on writing an associated usage document.  Abel will
encourage progress on both and report status to the mailing list.


The Personal Conferencing Specification

Abel Weinrib gave an overview of the Personal Conferencing
Specification.  Recently the Personal Conferencing Working Group
announced intention to include H.32Z.2 and H.261 in the specification.
The latter signals a move away from exclusive inclusion of a proprietary
video encoding technology.  H.32Z.2, which describes visual telephone
systems and terminal equipment, is focused on LAN transport but as
indicated by the editor of H22Z, there may be some overlap between it
and RTP.


The Session Description Protocol

Mark Handley (slides.4.95.b) provided an overview and in-depth
discussion of the Session Description Protocol (SDP). A continuation of
this discussion was the subject of the afternoon MMUSIC session.
Constructive comments and discussion resulted in about a dozen issues
that Mark and Van will address.  Some suggested changes which are
consistent with the general design goals encouraged further departure
from SDPv1 format (e.g., move start/stop times from conference data to
repeat time field).  Some issues were left as outstanding and will be
discussed on the mailing list (e.g., IPv4 vs IPv6 address formats in the
SDP header vs.  removing the field altogether as redundant with the
originating host field).  Mark Handley will circulate a detailed list of
suggested changes and outstanding issues to the mailing list.  A revised
Internet-Draft has been targeted for resubmission in June.


A Local Conference Control Architecture

Henning Schulzrinne (slides.4.95.c) described a local conference control
architecture which includes a message replicator, media agents, and
conference controllers.  The message replicator provides content-based
filtering and a lower-overhead alternative to local multicast
distribution of control messages.  He described an ASCII control message
protocol which uses hierarchical descriptors to name conference
components (similar to CCCP).


Relationship Between RTCP and Session Management Protocols

Steve Casner (slides.4.95.d) provided a brief overview of the
distribution of control functions with respect to RTP/RTCP. He described
a control issue raised on the rem-conf mailing list (error reporting),
and two approaches and their tradeoffs to providing additional control
functionality distribution:  adding application specific control
messages to RTCP, and placing needed functionality in another session
control protocol.  Due to lack of time, no discussion on this topic
occurred but is expected to continue on rem-conf.


An Application to Create Point-to-Point Conferences

Vinay Kumar described an application he has developed which uses MIME
e-mail and WWW to create point-to-point conferences using MBONE tools.
Use of e-mail as an invitation/rendezvous mechanism met Vinay's goals of
providing non-intrusive rendezvous.  Bill Fenner suggested that
``sd_launch'' could be used by Vinay's tool to support the creation of
multiparty conferences.


Interoperability Usage Scenarios

In addition to actions implied by the goals and milestones in the
charter, the goal of developing interoperability usage scenarios (MMUSIC
protocols with industry/international consortium standards) was
identified.  Carsten Bormann and Joerg Ott will lead this effort.