Multiparty Multimedia Session Control (mmusic)
----------------------------------------------

 Charter
 Last Modified: 2006-07-05

 Current Status: Active Working Group

 Chair(s):
     Colin Perkins  <csp@csperkins.org>
     Joerg Ott  <jo@acm.org>
     Jean-Francois Mule  <jf.mule@cablelabs.com>

 Real-time Applications and Infrastructure Area Director(s):
     Jon Peterson  <jon.peterson@neustar.biz>
     Cullen Jennings  <fluffy@cisco.com>

 Real-time Applications and Infrastructure Area Advisor:
     Cullen Jennings  <fluffy@cisco.com>

 Mailing Lists: 
     General Discussion:mmusic@ietf.org
     To Subscribe:      mmusic-request@ietf.org
         In Body:       subscribe your_email_address
     Archive:           http://www.ietf.org/mail-archive/web/mmusic/index.html

Description of Working Group:

The Multiparty MUltimedia SessIon Control (MMUSIC) Working Group was
chartered to develop protocols to support Internet teleconferencing
and multimedia communications. These protocols are now reasonably
mature, and many have received widespread deployment. The group is
now focussed on the revisions of these protocols in the light of
implementation experience and additional demands that have arisen
from other WGs (such as AVT, SIP, SIPPING, and MEGACO).

Multimedia communications protocols use a common platform to express
media and session descriptions: the Session Description Protocol, SDP.
The many uses of SDP have led to (requests for) numerous extensions
and have led to recognition of several flaws in the protocol design.
In spite of these, it is widely deployed.

- To support this current deployment, MMUSIC will revise SDP
suitable for publication as a Draft Standard RFC. This will
involve correcting minor bugs and clarifying the current
specification.

- Various extensions to SDP will be pursued to remedy the most
urgent of SDP's shortcomings. These will be limited to use of
SDP in conjunction with connection-oriented media such as TCP
and SCTP, offering support to work with NATs and firewalls
(e.g. via the ICE methodology), and exchange of media session
security keys.

With the exception of these specific items, only extensions within
the existing SDP framework will be done (e.g. registering new codecs
and defining parameters for them extending SDP to include new address
families).

To address the more fundamental issues with SDP, a next generation of
SDP, referred to as SDPng, will be needed. An initial proposal is now
available, and will be progressed to Experimental RFC while we gain
experience with implementations. An informational document will be
produced describing how the transition to a new session description
protocol can be managed, to prepare implementors for such a future
change.

MMUSIC will maintain and revise the specification of the Real Time
Streaming Protocol (RTSP), including fixes and clarifications based
on implementation experience. The revised RTSP specification will be
re-issued as a Proposed Standard RFC. We will also document how RTSP
can be used in the presence of NAT boxes.

An Internet Media Guide (IMG) is a collection of multimedia session
descriptions expressed using SDP or some other session description
format. It is used to describe a collection of multimedia sessions
(e.g. television programme schedules). The IMG must be delivered to
a potentially large audience, who use it to join a subset of the
sessions described, and who may need to be notified of changes to the
IMG.

MMUSIC will investigate delivery mechanisms for IMGs, generalizing
our work on session announcement and discovery protocols (SAP, RTSP,
SIP). We will investigate and document requirements for IMG delivery
mechanisms, and identify the requirements that these delivery
mechanisms impose on the session description formats used by the IMG.
We will then work to produce a framework document outlining the use
of (existing) protocols to create an IMG delivery infrastructure.
After successful completion of these initial milestones for IMG
delivery, the MMUSIC working group will decide whether or not MMUSIC
is the proper place to pursue any needed mechanisms for IMGs, and if
so, recharter accordingly

The MMUSIC work items will be pursued in close coordination with other
IETF WGs related to multimedia conferencing and IP telephony (AVT, SIP,
SIPPING, SIMPLE, XCON, MEGACO and, where appropriate, MIDCOM and NSIS).
Where appropriate, new separate working groups may be split off (as has
happened with the SIP WG).

The Working Group is also charged with addressing security issues
related to the protocols it develops.

 Goals and Milestones:

   Done         Conduct WG Last Call for SAP Internet-Draft 

   Done         Submit a revised Internet Multimedia Conferencing Architecture 
                I-D. 

   Done         Submit a revised SIP I-D. 

   Done         Submit SDP to the IESG for consideration as a Proposed 
                Standard. 

   Done         Submit SAP Internet-Draft to IESG for publication as an 
                Experimental Protocol. 

   Done         Conduct WG Last Call for RTSP Internet-Draft. 

   Done         Submit Internet-Draft on Internet Multimedia Conferencing 
                Architecture. 

   Done         Submit RTSP to IESG for consideration as a Proposed Standard. 

   Done         Conduct WG Last Call for SIP Internet-Draft. 

   Done         Submit SIP Internet-Draft to IESG for consideration as a 
                Proposed Standard. 

   Done         Conduct WG Last Call for SAP Security Internet-Draft. 

   Done         Conduct second WG Last Call for SAP. 

   Done         Submit SAP Internet-Draft to IESG for consideration as a 
                Proposed Standard. 

   Done         Submit SAP Security Internet-Draft to IESG for consideration as 
                a Proposed Standard. 

   Done         Submit IPv6 Extensions to SDP for Proposed Standard 

   Done         Submit SIP's offer/answer use of SDP for Proposed Standard 

   Done         Submit SDP4NAT for Proposed Standard (Informational?) 

   Done         Submit SDP source filter extensions for Proposed Standard 

   Done         Submit draft on SDPng motivations, comparisons with current SDP 
                capabilities. Request charter review on SDPng work from IAB and 
                IESG. 

   Done         Submit SDP security extension for Proposed Standard 

   Done         Submit IMG requirements and framework for Informational 

   Done         Submit revised SDP spec for Proposed (or Draft) Standard 

   Done         Submit SDP Offer/Answer examples for Informational 

   Aug 2004       Review work on IMGs and update charter accordingly 

   Done         Submit SDP connection-oriented media draft for Proposed 
                Standard 

   Done         Submit SDPng transition scenarios for Informational 

   Nov 2004       Submit SDPng base specification for Experimental 

   Nov 2004       Submit ICE draft for Proposed Standard 

   Feb 2005       Submit revised RTSP spec for Proposed or Draft Standard (as 
                appropriate) 

   May 2005       Submit RTSP NAT considerations draft 

   Done         Submit updated SDP Offer/Answer examples draft for 
                Informational 


 Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Feb 2002 Jun 2007   <draft-ietf-mmusic-rfc2326bis-15.txt>
                Real Time Streaming Protocol 2.0 (RTSP) 

Feb 2003 Jul 2007   <draft-ietf-mmusic-rtsp-nat-05.txt>
                An Network Address Translator (NAT) Traversal mechanism for 
                media controlled by Real-Time Streaming Protocol (RTSP) 

Oct 2003 Jul 2007   <draft-ietf-mmusic-ice-17.txt>
                Interactive Connectivity Establishment (ICE): A Protocol for 
                Network Address Translator (NAT) Traversal for Offer/Answer 
                Protocols 

Dec 2004 Apr 2007   <draft-ietf-mmusic-media-loopback-06.txt>
                An Extension to the Session Description Protocol (SDP) for 
                Media Loopback 

Feb 2005 Jul 2007   <draft-ietf-mmusic-securityprecondition-04.txt>
                Security Preconditions for Session Description Protocol (SDP) 
                Media Streams 

Mar 2006 Jul 2007   <draft-ietf-mmusic-ice-tcp-04.txt>
                TCP Candidates with Interactive Connectivity Establishment (ICE 

Dec 2006 Jun 2007   <draft-ietf-mmusic-file-transfer-mech-03.txt>
                A Session Description Protocol (SDP) Offer/Answer Mechanism to 
                Enable File Transfer 

Jan 2007 Jul 2007   <draft-ietf-mmusic-sdp-capability-negotiation-06.txt>
                SDP Capability Negotiation 

Jul 2007 Jul 2007   <draft-ietf-mmusic-rtsp-nat-evaluation-00.txt>
                The evaluation of different NAT traversal Techniques for media 
                controlled by Real-time Streaming Protocol (RTSP) 

Jul 2007 Jul 2007   <draft-ietf-mmusic-qos-identification-00.txt>
                Quality of Service (QoS) Mechanism Selection in the Session 
                Description Protocol (SDP) 

 Request For Comments:

  RFC   Stat Published     Title
------- -- ----------- ------------------------------------
RFC2326 PS   Apr 1998    Real Time Streaming Protocol (RTSP) 

RFC2327 PS   Apr 1998    SDP: Session Description Protocol 

RFC2543 PS   Mar 1999    SIP: Session Initiation Protocol 

RFC2974 E    Oct 2000    Session Announcement Protocol 

RFC3108 PS   May 2001    Conventions for the use of the Session Description 
                       Protocol (SDP)for ATM Bearer Connections 

RFC3259 I    May 2002    A Message Bus for Local Coordiantion 

RFC3266 PS   Jul 2002    Support for IPv6 in SDP 

RFC3264 PS   Jul 2002    An Offer/Answer Model with SDP 

RFC3388 PS   Dec 2002    Grouping of media lines in Session Description Protocol 
                       SDP 

RFC3524 PS   Apr 2003    Mapping of Media Streams to Resource Reservation Flows 

RFC3605Standard  Oct 2003    RTCP attribute in SDP 

RFC3890Standard  Sep 2004    A Transport Independent Bandwidth Modifier for the 
                       Session Description Protocol (SDP) 

RFC4091Standard  Jun 2005    The Alternative Network Address Types (ANAT) Semantics 
                       for the Session Description Protocol (SDP) Grouping 
                       Framework 

RFC4145Standard  Sep 2005    TCP-Based Media Transport in the Session Description 
                       Protocol (SDP) 

RFC4317 I    Dec 2005    Session Description Protocol (SDP) Offer/Answer Examples 

RFC4435 I    Apr 2006    A Framework for the Usage of Internet Media Guides 
                       (IMGs) 

RFC4473 I    May 2006    Requirements for Internet Media Guides (IMGs) 

RFC4566 PS   Jul 2006    SDP: Session Description Protocol 

RFC4572 PS   Jul 2006    Connection-Oriented Media Transport over the Transport 
                       Layer Security (TLS) Protocol in the Session Description 
                       Protocol (SDP) 

RFC4570 PS   Jul 2006    Session Description Protocol (SDP) Source Filters 

RFC4568 PS   Jul 2006    Session Description Protocol Security Descriptions for 
                       Media Streams 

RFC4567 PS   Jul 2006    Key Management Extensions for Session Description 
                       Protocol (SDP) and Real Time Streaming Protocol (RTSP) 

RFC4574 PS   Aug 2006    The Session Description Protocol (SDP) Label Attribute 

RFC4583 PS   Nov 2006    Session Description Protocol (SDP) Format for Binary 
                       Floor Control Protocol (BFCP) Streams 

RFC4756 PS   Nov 2006    Forward Error Correction Grouping Semantics in Session 
                       Description Protocol 

RFC4796 PS   Feb 2007    The Session Description Protocol (SDP) Content Attribute