CURRENT_MEETING_REPORT_ Reported by Craig Partridge/BBN MINUTES The TCP Large Windows WG met for half a day to discuss the two proposals (RFCs 1072 and 1106) for improving TCP for large delay-bandwidth paths. During the meeting two key issues were raised. The group determined that a key problem was how large to permit the window to be. A larger window makes it easier to consume the 32-bit sequence quickly. An example may help here. If one permits a window of 2^30 bytes, then in each round-trip time, one quarter of the sequence space can be consumed, and in four RTTs, the sequence space will recycle. However, a TCP cannot cycle the sequence space until it is sure the TTL of prior segments has expired (the forbidden zone problem). So, we were faced with choosing window sizes, that at anticipated speeds, didn't cause the sequence space to roll over in less than the anticipated TTL. In the end, the group was uncomfortable with this problem and has asked Van Jacobson and Bob Braden (both of whom have looked at this issue in more detail) to attend the next meeting. Another issue was whether we preferred to use options in every segment to expand the window, or preferred to find a way that didn't cause implementations to do expensive option handling. The consensus was to avoid option handling (which meant we preferred the rfc 1072 approach). Some discussion was given to generating a larger TCP header, but this conversation foundered when we checked the TCP header and found it lacked a version number. The group did not have time to consider another interesting proposal (passed on from the IETF Hosts group) to allow text error messages in RST segments. ATTENDEES Borman, Dave McCloghrie, Keith Elz, Robert McKenney, Paul Fox, Richard Miller, Dave Galvin, James M. Solensky, Frank Hedrick, Charles St.Johns, Mike Karels, Mike Yasaki, Brian Love, Paul