>> delayed ack sounds interesting.... > >Turning that off disables TCP slow-start. It's a huge performance >booster for things like SMB service, where you have lots of short-lived >TCP connections on a local net.
Uh, that's not what it does. Slow start is a behavior where the sender opens the window slowly - starting with one segment for the window and adding one more segment for each ack that comes back successfully. What the above option does is disable delayed acks on the receiver, thus reducing the round-trip time and increasing the speed of transaction style (small) TCP sends. Actually the real purpose of it is to eliminate the internal overhead that is normally imposed by the delayed ack timers, which can become substantial on large systems like wcarchive. That it has other beneficial side effects is almost accidental. :-) -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org Creator of high-performance Internet servers - http://www.terasolutions.com To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message
