It seems that net.inet.tcp.slowstart_flightsize does not work in 8-STABLE. For a long time I used slowstart_flightsize=2 on FreeBSD 4, 6, and 7 hosts. However, FreeBSD-8 always starts with the single packet. I saw this on different versions of 8-STABLE since 8 Oct 2009 till 04 Apr 2010. -- Igor Sysoev http://sysoev.ru/en/