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- Subject: N-1-4-030.60.2
-
- TECHNOLOGY AND TRENDS: IETF Audio & Videocast
- Ron Frederick, Xerox PARC
- <frederic@parc.xerox.com>
-
- Digital audio and video on the desktop is starting to become quite commonplace.
- Most modern workstations, and many PCs, come equipped with digital audio
- hardware of some sort, and video capture support is often available for a
- fairly low cost. Modern processors are finally fast enough to make processing
- of this audio and video data feasible without expensive coprocessor support,
- at least for simple tasks. This has led to an interesting new type of traffic
- on the Internet.
-
- In March of 1992, at the Internet Engineering Task Force (IETF) meeting in San
- Diego, there was a technology demonstration of digital audio on the Internet.
- The IETF general sessions and several of the working group sessions were
- "audiocast" out to about 20 remote sites, using IP multicast packet delivery
- of sampled audio on a SPARCstation. Remote listeners were spread all around
- the world. They could also talk back to the local IETF audience, and were able
- to participate in some of the working group sessions. The audio quality wasn't
- perfect, but overall it worked quite well, and was considered a great success.
-
- Since March, two other IETF meetings have been held, and this transmission of
- multimedia data across the Internet has continued to grow. At the last meeting
- in November, over 200 Internet networks in 15 countries were able to receive
- the broadcast, which at one point in the week included two simultaneous video
- and audio streams. To accomplish this, a mesh of routers were set up to provide
- multicast forwarding, and this has been named the "MBONE", or multicast
- backbone. This infrastructure has remained in place even after the IETF meeting
- and it was used to broadcast other meetings, such as the
- Australian Networkshop and the MCNC-CONCERT Packet Video Workshop in early
- December 1992.
-
- The IETF continues to pursue several issues related to this technology. In
- particular, there is a working group which is standardizing multicast extension
- s
- to the OSPF routing protocol, a working group developing a transport protocol
- suitable for real-time traffic such as audio and video, and a BOF which meets
- to talk about remote conferencing. Those interested in keeping up to date on
- this work, as well as future Internet audio and videocasts, should subscribe to
- the remote conferencing mailing list. To get more information, send a message
- to "rem-conf-request@es.net".
-