Transport Area Director: o Allison Mankin: mankin@cmf.nrl.navy.mil Area Summary Reported by Allison Mankin/NRL The Transport Area Directorate is comprised of the following members: Dave Borman, Sally Floyd, Jim Hughes, Matt Mathis, Greg Minshall, Eve Schooler, and John Wroclawski. The Transport Services Area deals with protocols and algorithms that provide end-to-end transmission services in the Internet. We maintain the notion of transport services, not just transport protocols, because of the increasing variety of end-to-end requirements that the Internet is meeting, or will be expected to meet, in the near future. In the month after the Seattle IETF, two working groups were added to Transport Services because of the closing down of the Service Applications Area: ONCRPC and THINOSI. They are covered in the SAP report for Seattle, but they fit well into the Transport Area Director and Directorate's sense of the scope of the Transport Services Area. Since the last report, we have increased the directorate, reflecting both the increase in the number of our active working groups and the area director's temporary assignment to co-direct the IP: Next Generation Area (with Scott Bradner). The directorate is primarily responsible for quality review of the working groups. They also contribute to our planning with their diverse and far-sighted perspectives on the Internet. Among the future issues for TSV that we are thinking on are: improving distributed file systems, fully documenting as standards TCP's adaptive algorithms (for the moment, Sally Floyd reports that the account in Richard Steven's TCP/IP Illustrated 2nd Edition will be correct and complete), completing selective acknowledgment in TCPLW, and developing an informational activity on the integrated layer processing technique, which is strongly related to transport services implementation issues. The Transport Services Area working groups that met in Seattle offer their brief summaries below. INT-SERV met as a BOF in Seattle, but it has since become a working group. ONCRPC is included in the SAP report for Seattle. Audio/Video Transport Working Group (AVT) The meeting began with a brief report on the status of the Real-time Transport Protocol (RTP). The draft RTP specification was submitted with a request for Last Call just before the previous IETF meeting in November. The review by the Transport Area Directorate called for several changes so that RTP would more closely follow the principles of application level framing. In two discussions between Steve Casner, Ron Frederick and Van Jacobson in which the vat and nv programs were taken as design examples, the following list of proposed changes was constructed: o Carry the control and data traffic on separate ports o Move the application-level multiplexing of the channel ID to an encapsulation, for the cases where it is needed o Minimize the use of options o Make the definition of some fields application-specific (in particular, the timestamp clock rate and sync marker) o Use global rather than local IDs, to be able to detect loops o Specify more precisely how reception reports should be provided The first 90 minutes of the first session, and the beginning of the second session were occupied by a presentation of these changes. The attendees generally agreed with the changes, and in particular agreed that the global identifiers would always be 32-bit random numbers rather than allowing the IPv4 address to be used as an identifier; as a consequence, the identifier of the synchronization source will always be included in a new field added to the fixed RTP header. There are several details remaining to be defined, in particular the mechanisms for padding the message to a multiple of the encryption block size, and for carrying the authentication information, and the exact structure of the control packet. Our task now is to complete the design to address these details, update the specification and get consensus from the working group via e-mail. Steve Casner will take responsibility for sending out a more complete draft of the proposed changes to start the discussion. The goal is to submit the draft for Last Call after review at the July IETF meeting in Toronto. Integrated Services Working Group (INTSERV) The first meeting was an organizational meeting, describing the motivations for the group, its organization, and timeline. The goal of INTSERV is to make the Internet friendly to real-time applications (e.g., multimedia conferencing) by enhancing the Internet architecture to support integrated services. The proposed working group organization calls for Craig Partridge to be the working group chair, and John Wroclawski, Scott Shenker and Dave Clark to be co-chairs. It was explained that the large management team is intended to ensure that the necessary outreach to various affected communities is made. The working group timeline calls for delivery of several RFCs over the next two years. The second session was devoted to trying to investigate what requirements integrated services might place upon IPng. Craig explained that this was definitely putting the cart before the horse, given that the group had barely had a chance to talk about proposed integrated services architectures, but at the request of the IPng Directorate, a discussion was held. At the end of the meeting, the proto-working group concluded that there were two requirements it would like to place on IPng: o That an IPng have some mechanism to locate per-datagram classification information (e.g., flow state) and that the mechanism should be consistent with forwarding at the media speeds expected in the future. o That an IPng should have mechanisms to hinder Bob from using or disrupting resources that Alice has been granted and is using. Craig Partridge was tasked to write up these points and circulate a draft to the working group, for consideration as submission as a white paper to the IPng directorate. Multiparty Multimedia Session Control Working Group (MMUSIC) During the Seattle meetings of the MMUSIC Working Group, there appeared to be a convergence of ideas about the general framework and protocols required for session control in the Internet, and a readiness to take steps toward interoperability of existing applications. The group identified at least two services that system builders might need and use; CCCP, a bus-based protocol that could provide an API-level messaging abstraction, and the agreement algorithm on which a session service could be built. In addition, there was interest in trying to understand, in the present context of the Internet/MBone/WWW, what constitutes a session and what are the functions that can be performed on sessions once they exist. Thus, a variety of session rendez-vous mechanisms were described. A final discussion focused on the relevance of reliable multicast to a membership management protocol. From formal and informal conversations with working group participants, it was clear that these ideas are ready to be codified and written down. Resource Reservation Setup Protocol Working Group (RSVP) The RSVP Working Group met twice during the Seattle IETF. The first session was devoted to an overview of the protocol and a report on the status of an initial implementation. Several issues were raised and discussed. The second session was largely devoted to further discussion of a number of basic issues. The working group plans to hold an MBone conference before the next IETF meeting (the MBone meeting has been scheduled for 23 June), and to conduct further discussion by e-mail. There were several action items to prepare position papers on particular issues. The draft specification will be updated with some additions suggested at the meeting. Many of the hard issues under discussion concerned functional modularity, especially between resource reservation and routing.