Tweak network settings

Note: I don't know if this really helps, maybe you better just leave it as it is.

• http://ubuntuguide.org/wiki/Ubuntu:Hardy#Howto:_Tweak_and_maximize_your_bandwidth_in_Ubuntu.2FLinux_via_sysctl.21

sudo gedit /etc/sysctl.conf

Add to end:

## increase TCP max buffer size setable using setsockopt()
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
## increase Linux autotuning TCP buffer limits
## min, default, and max number of bytes to use
## set max to at least 4MB, or higher if you use very high BDP paths
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
## dont cache ssthresh from previous connection
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
## recommended to increase this for 1000 BT or higher
net.core.netdev_max_backlog = 2500
## for 10 GigE, use this, uncomment below
# net.core.netdev_max_backlog = 30000
## Turn off timestamps if youre on a gigabit or very busy network
## Having it off is one less thing the IP stack needs to work on
# net.ipv4.tcp_timestamps = 0
## disable tcp selective acknowledgements.
net.ipv4.tcp_sack = 0
##enable window scaling
net.ipv4.tcp_window_scaling = 1