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). 1 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 2