CURRENT_MEETING_REPORT_ Reported by Peter Honeyman/University of Michigan SYNOPSIS Trans- and inter-continental distributed file systems are upon us. The consequences to the Internet of distributed file system protocol design and implementation decisions are sufficiently dire that we need to investigate whether the protocols being deployed are really suitable for use on the Internet. There's some evidence that the opposite is true, e.g., some DFS protocols don't checksum their data, don't use reasonable MTUs, dont offer credible authentication or authorization services, dont attempt to avoid congestion, etc. Accordingly, a working group on DFS has been formed by the IETF. The WG will attempt to define guidelines for ways that distributed file systems should make use of the network, and to consider whether any existing distributed file systems are appropriate candidates for Internet standardization. The WG will also take a look at the various file system protocols to see whether they make data more vulnerable. This is a problem that is especially severe for Internet users, and a place where the IETF may wish to exert some influence, both on vendor offerings and user expectations. dfs-wg@citi.umich.edu is a mailing list for ongoing discussions of the WG; administrative matters, such as requests to be added or dropped from the list, should be addressed to dfs-wg-request@citi.umich.edu, not to the list as a whole. MINUTES The meeting was chaired by Peter Honeyman. At the meeting, plans were made to meet the following objectives. OBJECTIVE: Produce a document for implementors and administrators, in the style of the Hosts Requirements RFCs. Issues to be addressed include recommendations to be followed when UDP is used as the transport layer. Most of these recommendations come from experiences with TCP. The recommendations include: o the use of the transport-layer checksum; o techniques for congestion avoidance; o techniques for fragmentation avoidance; o retransmission strategy based on measured round-trip times. 1 The group intends to identify other recommendations and to flesh out the details in time for a review at the next IETF meeting. OBJECTIVE: Standard for Kerberos authentication for NFS. Several groups have deployed or are preparing to deploy NFS integrated with Kerberos. Among these are MIT, U Michigan, and Transarc, Inc.. These groups will describe the protocols they now use for establishing and maintaining Kerberos credentials in an NFS session. The intent is to agree on a common protocol, which will be described in an RFC. Representatives from MIT, Michigan, and Transarc agreed to describe their protocols in the dfs-wg mailing list. At the next meeting of the IETF, substantive differences between the protocols will be discussed. OBJECTIVE: Establish the requirements for Internet-friendly DFS protocols. DFS protocols that were developed for a LAN environment can behave abysmally on a WAN. A well designed DFS will balance its performance needs with those of other users and uses of the network. Many of the issues concerning the design of DFS protocols depend on one another, or on advances in other areas under study by the IETF. A partial list of the areas in which recommendations can be made includes: o Naming o Data representation o Type management o Locking o Impact of design choices: - Statelessness - Cache management - Choice of transport o Use of MTU discovery o Authentication and authorization o Trusted vs. untrusted client o Time protocol o User expectations The first task is to establish concrete goals to guide the WG in this area. GOALS FOR NEXT IETF MEETING ``Guidelines for DFS Administrators and Implementors'' in draft form. Current status of Kerberized NFS implementations on paper. Further discussion on "Guidelines for DFS Designers." 2 ATTENDEES Richard Basch probe@mit.edu Dave Borman dab@cray.com Peter Honeyman honey@citi.umich.edu Mike Karels karels@berkeley.edu Ole Jacobsen ole@csli.stanford.edu Dan Jordt danj@washington.edu Loius A. Mamakos louie@trantor.umd.edu Tony Mason mason@transarc.com Matt Mathis mathis@pele.psc.edu Leo J. McLaughlin ljm@twg.com Greg Minshall minshall@kinetics.com Don Morris morris@ucar.edu Drew Perkins ddp@andrew.cmu.edu Joel Replogle replogle@ncsa.uiuc.edu Dean Throop throop@dg-rtp.dg.com A. Lee Wade wade@orion.arc.nasa.gov Dan Wintringham ydanw@osc.edu 3