Disable tcp slow start

问题:

I am looking for disable tcp slow start mechanism for high-speed network. Currently clients send 100MB flows to random servers with non-blocking 1Gbps link. In my math, the completion time of the flows is less than 1 second.

But the problem is that they cannot reach to a full link bandwidth. In other words, they are finished at slow start phase before getting a full link bandwidth. Therefore, I want to increase tcp congestion window size to maximum.

Is there anyone who know how I change that value easily without modification of kernel?

Thx~

回答1:

On Linux platforms the SSR setting can be checked and disabled via the following commands:

$> sysctl net.ipv4.tcp_slow_start_after_idle
$> sysctl -w net.ipv4.tcp_slow_start_after_idle=0

Slow start is also used after a connection has been idle, unless this behavior is disabled in

/proc/sys/net/ipv4/tcp_slow_start_after_idle.