CURRENT_MEETING_REPORT_ Reported by Andy Nicholson/Cray Research, Inc. CBNR BOF Minutes Description: We held a BOF on this subject at the 20th IETF in St. Louis, and this is a continuation of that interchange. However, the only attendees from the St. Louis meeting present at this meeting were the Cray Research, Inc. representatives. While working with circuit-switched T3 networks, developers at Cray Research, Inc., determined that there would be advantages to defining a standard way to control certain classes of network resources through the internet. In the case of a circuit-switched T3 line, the line should be switched on only when there are active transport connections which can fully utilize the service. Due to the high cost of the resource, under-utilization would be particularly undesirable. The developers believe that this capability might have other applications in the internet and that an effort should be made to define a standard protocol. Minutes: Due to the small size and informality of the meeting, no formal Minutes were taken. This record is believed to be reasonably accurate and proper credit given to the originators of the ideas and concepts presented. Andy Nicholson, who is preparing this report, apologizes for any errors or omissions. A variety of new issues were brought up at this meeting, and it was encouraging to note that there were as many non-Cray people as Cray employees. Most of the discussion centered around the concrete example of the Circuit-Switched T3 services being prototyped by Cray Research, Inc. The first issue raised centered on local routing to the T3 adapter. This would include routing to any controlled device. The prototypes assume that a particular network link will be used for transfer of data packets, thus static routing is implied. There is concern that this perspective may lead to the use of static routing between the requesting host and the controlled resource. There was general agreement that this should not happen. Another issue concerned recursive conditioning of resources. A host in control of a link might need to pass a request to another host through the controlled link so that further downstream links may be conditioned. This should be possible. Fred noted that some comparisons could be made with regard to this capability. For example, this is similar to the switching which takes 1 place through the telco fabric as calls are routed. There is also a similarity to X.25. For example, TP0 will create a link over x.25 when a connection is established. Matt did not think that this could be a widely deployed function; however, Fred noted that this might be useful in any kind of fundamentally switched service, i.e. ISDN or mobile hosts. This seems like something that is in the future. In the Cray Research, Inc. prototype, most of the support code is in the kernel. Matt and Fred were concerned that perhaps this should all reside in user space. This leads to two fundamentally different approaches. For everything to be in user space, either special commands must be executed to condition the network before running applications, or the applications must make special library calls. If everything is in the kernel, then these services can be transparent to users and applications. These discussions led us to a very different conclusion from the last meeting. All agreed that I would finish an informational RFC relating our experiences with the switched T3 services in time for review by the community before the next IETF. If possible, I will also document the protocol we are using. At the 22nd IETF we will once again hold a BOF to gauge interest in these facilities. At that meeting we will determine whether to continue any work through the IETF. Attendees Fred Baker fbaker@emerald.acc.com David Borman dab@cray.com Matt Mathis mathis@psc.edu Andy Nicholson droid@cray.com John Seligson johns@ultra.com Jeff Young jsy@cray.com 2