Protocols for Negotiated-QOS Multicast Communicat. (qosmc) Concluded WG

Note: The data for concluded WGs is occasionally incorrect.

WG Name Protocols for Negotiated-QOS Multicast Communicat.
Acronym qosmc
Area Transport Area (tsv)
State Concluded
Charter charter-ietf-qosmc-01 Approved
Dependencies Document dependency graph (SVG)
Personnel Chair Jack Houldsworth

Charter for Working Group

For some time, SC 6 and ITU-T SG 7 have been developing specifications
for multi-party communications in what would traditionally be labelled
the Transport layer -- that is, above the Network layer, and of a
general nature to support a range of different kinds of application. The
two major features of the work that go beyond traditional Transport
protocols are multicast operation, and the provision of means to
express, negotiate and maintain the quality of service of communication
in a multi-party environment.

The multicast provision considered is biased towards relatively small
groups of communicating participants. In the current and near-term
marketplace, we would also expect deployment and use of such protocols
to be biased towards the intranet environment, more than the global
Internet; in the longer term, that bias might very well change.

In parallel with development of the protocol specifications, there have
been two implementation projects (in Germany and Korea) that are now
able to demonstrate the effectiveness of the approach that has been

Early work, now completed, on ECTS (Enhanced Communications Transport
Service) has been used to focus and direct the protocol development. We
have tried to identify, and so avoid re-inventing, existing protocols
which could meet some of the needs (eg RTP); and conversely, to identify
gaps where new protocols need to be developed. Related work has
identified the requirement for associated, ancillary, protocols --
possibly generic, possibly related to particular kinds of application
area -- and some experimental work in these areas has been carried out.

The resulting protocol development work -- labelled ECTP -- deals with
two main areas: firstly, a set of protocol functions that provide a
framework for control of multicast conversations, including negotiation
of a wide range of possible quality of service values, and consequent
selection of suitable bearer protocols at or just above the Network
layer for the actual data transfer; and secondly, development of a
specific multicast bearer protocol offering a range of reliability

The BOF is envisaged as the first of a possible two-stage introduction
of this SG 7 and SC 6 work to the wider development arena of the IETF.
We hope and expect to stimulate wider interest and participation in
further developing some strands of the technical work, including some
that would take advantage of IETF work such as RTP. To facilitate this
we intend to set up a dedicated e-mail exploder (ie separate from the
existing sc6wg7 exploder, which will continue to be used for other WG 7
business). According to the results of such activity, we would hope to
generate a further BOF session at a subsequent IETF meeting, with a view
to pursuing well identified work items in a suitably chartered new
Working Group.

Other outcomes are recognised as being possible. There may not be enough
interest; there may be interest, but in development areas that turn out
to fit in existing Working Groups. (For example, some of the work that
has been contributed on associated protocols, for information and
context, clearly belongs within the intended (future) scope of MMUSIC,
and would be pursued in that forum at the appropriate time.)


Date Milestone