CURRENT_MEETING_REPORT_ Reported by Robert Braden/Information Sciences Institute Minutes of the Real-time Packet Forwarding and Admission Control BOF (REALTIME) The demand for multimedia communication, and the success of IETF audio/videocasts, will soon create an urgent requirement for resource reservation and control in the Internet. From an architectural viewpoint, this represents a new Internet service model. Such a service model should include, in an integrated fashion, both real-time and link-sharing services along with the traditional best-effort datagram services. Research in DARTnet has developed (a) an integrated service model for the Internet, and (b) a particular set of mechanisms to realize this model. To provide end-to-end service suitable for realtime applications, the routers must all implement the same service model, although there may be alternative mechanisms. The group therefore proposes that the service model be standardized. This BOF will describe the service model and the realization, and suggest the service model as a candidate for Internet standardization. The session was opened by Scott Shenker, who noted that Bob Braden, one of the BOF chairs, could not be present due to concerns about his home in the current LA fires. Scott delivered a talk on the necessity of explicit service models in the Internet. He described the taxonomy of service models that are proposed in the related Internet-Draft. He stressed that this proposal is not for a closed set of service models, but for a growing set of explicit models. He also mentioned dissenting opinions from the loyal opposition, who would prefer an approach without explicit service models or explicit service reservations. Scott continued by presenting and discussing three fundamental questions. 1. Why do we need a service model? The answer is efficiency. He argued that implementing an explicit mechanism is more effective than expending bandwidth in improving overall service, and this mechanism can only be introduced in the context of a model that defines the objective of the mechanism. 2. Should the service model be explicit or implicit? He advocated that binding between application and service should be determined by the application, outside the network, rather than internally to the network. 3. Is admission control necessary? He argued that, at least for heavy users, occasional blocking is a much more economical approach than vast over-provisioning. He then took a straw poll which, while informal, suggested that there was not wide dissension to his conclusions to the above questions. A discussion of service models followed. There was support for the concept of admission control. David Clark then gave a talk on the way in which routers must be constructed in order to realize the service models discussed earlier. He used the guaranteed real-time service as an example of behavioral characterization of router functionality. More discussion followed. It was observed that behavioral characterization of functionality is a very difficult intellectual problem, and that it was important that the community not get bogged down in this exercise. We must start to implement and deploy routers and get real experience at the same time we work towards a formal performance characterization. It was observed that while the presentation had emphasized router requirements, there will also be a need for ``subnetwork requirements'' or ``link level requirements.'' In the past, the Internet has demanded relatively little of its subnet technology, but these QOS requirements will change that. ATM, in particular, must fit into this architecture in a harmonious way. The BOF ended at 9:30, due to exhaustion of all parties. There was an informal assessment that a working group ought to be formed. Attendees Anthony Alles aalles@cisco.com Robert Braden braden@isi.edu Scott Brim Scott_Brim@cornell.edu Theodore Brunner tob@thumper.bellcore.com Stephen Casner casner@isi.edu John Chang jrc@uswest.com David Clark ddc@lcs.mit.edu Ed Ellesson ellesson@vnet.ibm.com Roger Fajman raf@cu.nih.gov Mark Garrett mwg@faline.bellcore.com Robert Gilligan Bob.Gilligan@Eng.Sun.Com Daniel Grossman dan@merlin.dev.cdx.mot.com Robert Hinden hinden@eng.sun.com Phil Irey pirey@relay.nswc.navy.mil Van Jacobson van@ee.lbl.gov Ronald Jacoby rj@sgi.com Frank Kastenholz kasten@ftp.com Mark Laubach laubach@hpl.hp.com Bryan Lyles lyles@parc.xerox.com Dan Magorian magorian@ni.umd.edu Andrew Malis malis@maelstrom.timeplex.com David Marlow dmarlow@relay.nswc.navy.mil Thomas Maslen maslen@eng.sun.com Keith McCloghrie kzm@hls.com Greg Minshall minshall@wc.novell.com Karen O'Donoghue kodonog@relay.nswc.navy.mil Steve Parker sparker@ossi.com Drew Perkins ddp@fore.com Allyn Romanow allyn.romanow@eng.sun.com Hal Sandick sandick@vnet.ibm.com Henning Schulzrinne hgs@research.att.com Andrew Smith asmith@synoptics.com Michael Speer michael.speer@sun.com Abel Weinrib abel@bellcore.com