Tuning Networking Parameters in Mac OS X

Spotted via Mac OS X Hints is an article on tuning your network stack on OS X for increased throughput.

Mac OS X has a single sysctl parameter, kern.ipc.maxsockbuf, to set the maximum combined buffer size for both sides of a TCP (or other) socket. In general, it can be set to at least twice the BDP. E.g:

sysctl -w kern.ipc.maxsockbuf=8000000

The default send and receive buffer sizes can be set using the following sysctl variables:

sysctl -w net.inet.tcp.sendspace=4000000

sysctl -w net.inet.tcp.recvspace=4000000

If you would like these changes to be preserved across reboots you can edit /etc/sysctl.conf.

You can use Apple's Broadband Tuner to add the necessary startup items and then put the required parameters into your /etc/sysctl.conf file to have them automatically reloaded at each reboot.

Original Article is here:Enabling High Performance Data Transfers [PSC]