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- CURRENT_MEETING_REPORT_
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- Reported by Peter Honeyman/University of Michigan
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- SYNOPSIS
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- 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.
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- 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.
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- 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.
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- 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.
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- MINUTES
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- The meeting was chaired by Peter Honeyman. At the meeting, plans were
- made to meet the following objectives.
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- OBJECTIVE: Produce a document for implementors and administrators, in
- the style of the Hosts Requirements RFCs.
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- 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:
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- 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.
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- The group intends to identify other recommendations and to flesh out the
- details in time for a review at the next IETF meeting.
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- OBJECTIVE: Standard for Kerberos authentication for NFS.
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- 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.
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- 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.
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- OBJECTIVE: Establish the requirements for Internet-friendly DFS
- protocols.
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- 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.
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- 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:
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- 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
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- The first task is to establish concrete goals to guide the WG in this
- area.
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- GOALS FOR NEXT IETF MEETING
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- ``Guidelines for DFS Administrators and Implementors'' in draft form.
- Current status of Kerberized NFS implementations on paper. Further
- discussion on "Guidelines for DFS Designers."
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- ATTENDEES
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- 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
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