Just for your information, on OS X 10.6 at least: $ sysctl -a net.inet.tcp.sack net.inet.tcp.sack: 1 It looks like somewhere after 10.4 they implemen

Just for your information, on OS X 10.6 at least: $ sysctl -a net.inet.tcp.sack net.inet.tcp.sack: 1 It looks like somewhere after 10.4 they implemented it.