N-1-3-Casner, "Second IETF Internet Audiocast", by Steve Casner, The July IETF meeting in Boston marked the second step in a continuing experiment that may eventually lead to geographically distributed IETF meetings. Live audio and video from the IETF meeting site was transmitted using IP multicast UDP packets over the Internet to participants in 10 countries (AU, CA, CH, FR, JP, NL, NO, SE, UK, US). The audio transmission was received by 170 workstations using built-in audio hardware and packet audio software. This number is up from 20 for the first IETF "audiocast" in March, plus this time slow frame rate video was transmitted and displayed via software decompression on 75 of the workstations. It is conceivable that by the next IETF meeting or two, there could be more remote participants than local attendees! That's not to say we've overcome the need to travel to IETF. Remote participants are able to talk back, as was demonstrated very impressively during the open IESG meeting session, but remote participation is not the same as being there. We hope to see two-way video, "shared whiteboards" and other improvements added in the future. However, we are a long way from being able to support full participation in all the simultaneous working group sessions, not to mention solving the problems introduced by a span of 16 time zones. We must also wait for resource management to be implemented in the Internet before real-time traffic can be accommodated on any significant scale. This experiment is largely a volunteer effort. Steve Deering and I served as ring-leaders, but we were assisted by several people who set up equipment and/or provided software: Bob Clements, John Curran, Chuck Davin, Ron Frederick, Van Jacobson, Paul Milazzo, Jeff Schiller, and Henning Schulzrinne. In addition, many people around the global Internet provided multicast tunnel machines to build the largest IP multicast topology to date -- at one point during the week, the multicast routing table included 90 separate subnets. Since IP multicast routing support has not yet been integrated into many production routers, it is necessary to construct a virtual multicast network of tunnels layered on top of the physical backbone and regional networks. To reach the many more places that would like to participate, we'd like to expand the IETF multicast topology to form a semi-permanent Multicast Backbone, dubbed MBONE, to serve as a testbed for continued experimentation. To manage the growth, we're looking for assistance from regional and backbone network providers to set up and operate multicast tunnel machines and distribute the multicast traffic on to their customers. To organize this effort, we've established some regional email lists. If you are a network provider willing to help, please send a message to the appropriate request-list for your area: ozaudio-request@internode.com.au Australia mbone-eu-request@sics.se Europe mbone-request@isi.edu US & other End-user sites who want to participate in IETF multicasts should contact their network providers directly and encourage them to participate!