Subject: MMUSIC minutes

From: Ruth Lang <[email-masked]>
Date: Tue, 02 May 1995 16:30:18 -0700

FYI.  Enclosed are the minutes for the MMUSIC meeting that was held 4/5/95.

Ruth Lang

--------------------------

      Multiparty Multimedia Session Control (MMUSIC) Working Group
	                Minutes from the 32nd IETF
	                  Danvers, Massachusetts
        	             April 5, 1995

				Chairs

		Mark Handley, [email-masked]
	 	Ruth Lang, [email-masked]
		Eve Schooler, [email-masked]

These notes were prepared by Ruth Lang.  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 April 5 at the
32nd IETF.

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 [email-masked].  The
revised charter will be sent for review by the Transport Area Chair
and subsequent submission to the IESG in April.

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
[email-masked].

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.

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 field altogether as redundant with
originating host field).  Mark Handley will circulate a detailed list
of suggested changes and outstanding issues to [email-masked].  An
revised Internet-Draft has been targeted for resubmission in June.

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).

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.

Vinay Kumar described an application he has developed which uses MIME
email and WWW to create point-to-point conferences using MBONE tools.
Use of email 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.

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.