6. Networking
Enabling and disabling some of the advanced features of TCP: (Usually it is a good idea for these to be enabled)
/proc/sys/net/ipv4/tcp_timestamps
/proc/sys/net/ipv4/tcp_window_scaling
/proc/sys/net/ipv4/tcp_sack
To enable all these features, for example, do the following as root:
echo 1 > /proc/sys/net/ipv4/tcp_timestamps
echo 1 > /proc/sys/net/ipv4/tcp_window_scaling
echo 1 > /proc/sys/net/ipv4/tcp_sack
Tuning the default and maximum window sizes:
/proc/sys/net/core/rmem_default - default receive window
/proc/sys/net/core/rmem_max - maximum receive window
/proc/sys/net/core/wmem_default - default send window
/proc/sys/net/core/wmem_max - maximum send window
/proc/sys/net/ipv4/tcp_rmem - memory reserved for TCP rcv buffers
/proc/sys/net/ipv4/tcp_wmem - memory reserved for TCP snd buffers
The following values would be reasonable for path with a large BDP:
echo 8388608 > /proc/sys/net/core/wmem_max
echo 8388608 > /proc/sys/net/core/rmem_max