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Version 4.02, 2012-04-26
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Multiparty Multimedia Session Control (mmusic)

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 deployments. The group has revised
some of these protocols in the light of implementation experience and
additional demands that have arisen from other WGs (such as AVT, SIP,
and SIPPING). It is focused on using and negotiating mechanisms such
STUN and TURN in order to enable media sessions to traverse Network
Address Translators NATs, and on new means to exchange SDP capabilities.

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, some of
which were addressed in the revision of SDP. In spite of these, it is
widely deployed.

The current aims of the working group include the following:

- To support the establishment of multi-party multimedia sessions across
NATs, MMUSIC will define an Internet Connectivity Establishment
protocol (ICE). This will define several SDP extensions to work with
NATs for media sessions carried over both UDP and TCP.

- Various extensions to SDP will be pursued to remedy the most urgent of
SDP's shortcomings. These will be limited and include adding support
for limited but generic capability negotiations in SDP, defining the
means to select QoS mechanisms to use for a particular media stream,
enabling file transfer via the SDP Offer/Answer model, and support
for
media loopback.

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 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.

The MMUSIC work items will be pursued in close coordination with other
IETF WGs including AVT, SIP, SIPPING, SIMPLE, XCON, and BEHAVE, as well
as others where appropriate such as NSIS.

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
Done 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
Done Submit ICE draft for Proposed Standard
Done Submit updated SDP Offer/Answer examples draft for Informational
Done Submit SDP Offer/Answer exchange for enabling file transfer as a Proposed Standard
Done Submit QoS Mechanism Selection in SDP as a Proposed Standard
Done Submit SDP Capability Negotiations to Proposed Standard
Done Submit Source-Specific Media Attributes in SDP as Proposed Standard
Done Submit Connectivity Preconditions for SDP Media Streams as Proposed Standard
Done Signaling media decoding dependency in SDP
Done Submit revised RFC for Grouping of Media Lines in SDP
Done Submit an update to the FEC Grouping Semantics in SDP as Proposed Standard
Done Submit ICE Options Registry as a Proposed Standard
Done Submit SDP Image Attribute as Proposed Standard
Done Submit ICE-TCP draft as a Proposed Standard
Done Submit IANA registration of 'image' media type in SDP as Proposed Standard
May 2012 Submit SDP extensions for Media Loopback for Proposed Standard
May 2012 Submit SDP extensions for Media Capability Negotiations as Proposed Standard
Jun 2012 Submit SDP extensions for audio media streams over Circuit- Switched bearers as Proposed Standard
Jun 2012 Submit revised RTSP spec for Proposed or Draft Standard (as appropriate)
Jun 2012 Submit SCTP-Based Media Transport in SDP as Proposed Standard
Jun 2012 Submit SDP extensions for Media Titles and Media Bandwidth Capability Negotiations as Proposed Standard
Jul 2012 Submit revised SDP specification to IETF for Proposed Standard
Jul 2012 Submit Offer/Answer Examples as Informational
Aug 2012 Submit RTSP NAT considerations draft as a Proposed Standard
Aug 2012 Submit SDP extensions to classify traffic as Proposed Standard
Sep 2012 Submit Considerations for using SDP offer/answer with middleboxes for BCP
Sep 2012 Submit SDP extension to signal parallax information as Proposed Standard
Sep 2012 Submit SDP extension to signal stereoscopic 3D video as Proposed Standard
Nov 2012 Submit SDP extensions to negotiate multiplexed media streams as Proposed Standard