Multiparty Multimedia Session Control

Document Proposed charter Multiparty Multimedia Session Control WG (mmusic)
Title Multiparty Multimedia Session Control
Last updated 2019-02-06
State Start Chartering/Rechartering (Internal IESG/IAB Review) Rechartering
WG State Active
IESG Responsible AD Ben Campbell
Charter Edit AD Ben Campbell
Telechat date (None)
Has enough positions to pass.
Send notices to (None)


The Multiparty MUltimedia SessIon Control (MMUSIC) Working Group was
originally chartered to develop protocols to support Internet teleconferencing
and multimedia communications. These protocols are now reasonably mature, and
many have received widespread deployment. Currently, the group is focused on
using and negotiating media streams with the Session Description Protocol
(SDP), which is used as a common protocol to express media and session
descriptions. The group also maintains the Real-time Streaming Protocol (RTSP)
and Interactive Connectivity Establishment (ICE) specifications.

The protocols have been revised in the light of implementation experience and
additional demands that have arisen from other WGs (such as AVTCORE, CLUE, ICE,
and RTCWEB). In particular, the many uses of SDP have led to requests for
numerous extensions as well as a recognition of several limitations in the
original protocol design. Today, the SDP protocol is widely deployed and
continues to see extensions being defined.

The current aims of the working group include the following:

- Provide SDP signaling support for the Interactive Connectivity Establishment
(ICE) protocol and its extensions.

- To support the establishment of multi-party multimedia sessions for RTCWEB
based implementations, MMUSIC provides SDP signaling support for a number of
extensions required by RTCWEB. The MMUSIC WG will seek a balanced trade-off
between general applicability of such extensions versus RTCWEB specific usage.

- Various other extensions to SDP may be pursued to remedy the most urgent of
SDP's shortcomings. These include updates to the SDP specification itself
and missing IANA registrations.

- Maintain the specification of the (revised) Real Time Streaming Protocol
(RTSP) as needed.

- Maintain the specifications of the Interactive Connectivity Establishment
(ICE) and specify extensions to it where there is demonstrated interest and

- With the exception of the items listed above, only extensions within the
existing SDP framework will be done.

The MMUSIC work items will be pursued in close coordination with other IETF WGs
including AVTCORE, RTCWEB, and SIPCORE, as well as others where

Proposed milestones

No milestones for charter found.