CURRENT_MEETING_REPORT_

Reported by Craig Partridge/BBN



MINUTES

The working group made progress on deciding what to do about the options
to support large TCP windows.

Key concerns were making the window size big enough so that a full
window could fill a gigabit pipe and expanding the sequence space large
enough that it wouldn't be consumed too fast at a gigabit.

The WG made the following tentative decisions about how to deal with big
windows:

  1. The RFC 1072 window shift option will be used to expand the window
     size (everyone likes it, and implementation is a snap).
  2. We'll create a new Urgent Pointer option so it can point to urgent
     data anywhere in the expanded window.  (To use it, the URG bit is
     left off -- when the receiver processes options, it will see that
     there is urgent data).
  3. The WG was divided among two options for expanded the sequence and
     ack space.  Thankfully some folks with supercomputers offerred to
     implement both options and report back this spring.  The two
     options were:
     (a) since we need an URG option anyway, steal the urgent field in
         the TCP header to get 8 more bits for each of the sequence #
         and the ack #.  These would be high order bits.
     (b) don't futz with the header (note that in most cases urgent data
         is likely to be within 2**16 of the current sequence number and
         thus the urgent field is still useful).  Instead, put an option
         at the end of each segment header, which contains an additional
         high order 16-bits of the sequence number and the ack number.

Based on the implementation experience, the WG will decide which path to
take.

People interested in participating in the experiment should contact Dave
Borman (dab@cray.com).



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ATTENDEES

     Doug Bagnall                     bagnall_d@apollo.hp.com
     Dave Borman                      dab@cray.com
     Richard Fox                      sytek!rfox@sun.com
     Mike Karels                      karels@berkeley.edu
     Walt Lazear                      lazear@gateway.mitre.org
     Paul Love                        loveep@sds.sdsc.edu
     Gary Malkin                      gmalkin@proteon.com
     Paul E. McKenney                  mckenney@sri.com
     Don Merritt                      don@brl.mil
     Lee Oattes                       oattes@utcs.utoronto.ca
     Craig Partridge                   craig@bbn.com
     K.K. Ramakrishnan                 rama@dsmial.dec.com
     Joel Replogle                     replogle@ncsa.uiuc.edu
     Frank Solensky                    solensky@interlan.com
     Mike St.  Johns                   stjohns@umd5.umd.edu
     Allen Sturtevant                  sturtevant@ccc.nmfecc.gov
     Rick Wilder                      rick@gateway.mitre.org
     Brian Yasaki                     bky@twg.com



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