NOTE: This charter is accurate as of the 29th IETF Meeting in Seattle. It
may now be out-of-date. (Consider this a "snapshot" of the working
group from that meeting.) Up-to-date charters for all active working
groups can be found elsewhere in this Web server.
Audio/Video Transport (AVT) Charter
- Stephen Casner <email@example.com>
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Description of Working Group
The Audio/Video Transport Working Group was formed to specify experimental
protocols for real-time transmission of audio and video over UDP
and IP multicast. The focus of this group is near-term and its
purpose is to integrate and coordinate the current AVT
efforts of existing research activities. No standards-track
protocols are expected to be produced because UDP transmission of
audio and video is only sufficient for small-scale experiments
over fast portions of the Internet. However, the transport
protocols produced by this working group should be useful on a larger scale
in the future in conjunction with additional protocols to access
network-level resource management mechanisms. Those mechanisms,
research efforts now, will provide low-delay service and guard
against unfair consumption of bandwidth by audio/video traffic.
Similarly, initial experiments can work without any connection
establishment procedure so long as a priori agreements on port
numbers and coding types have been made. To go beyond that, we
will need to address simple control protocols as well. Since IP
multicast traffic may be received by anyone, the control
protocols must handle authentication and key exchange so that the
audio/video data can be encrypted. More sophisticated connection
management is also the subject of current research. It is
expected that standards-track protocols integrating transport,
resource management, and connection management will be the result
of later working group efforts.
The AVT Working Group may design independent protocols specific to each
medium, or a common, lightweight, real-time transport protocol
may be extracted. Sequencing of packets and synchronization
among streams are important functions, so one issue is the form
of timestamps and/or sequence numbers to be used. The working group will
not focus on compression or coding algorithms which are domain of
Goals and Milestones
- Define the scope of the working group, and who might contribute. The first step will be to solicit contributions of potential protocols from projects that have already developed packet audio and video. From these contributions the group will distill the appropriate protocol features.
- Conduct a teleconference working group meeting using a combination of packet audio and telephone. The topic will be a discussion of issues to be resolved in the process of synthesizing a new protocol.
- Review contributions of existing protocols, and discuss which features should be included and tradeoffs of different methods. Make writing assignments for first-draft documents.
- Post an Internet-Draft of the lightweight audio/video transport protocol.
- May 1993
- Post a revision of the AVT protocol addressing new work and security options as an Internet-Draft.
- Jun 1993
- Submit the AVT protocol to the IESG for consideration as an Experimental Protocol.
NOTE: The Internet-Draft(s) listed below may have been deleted
since they are only good for six months.