changing initcwnd to get better performance

[s***@gmail.com]

Hi,

I want to increase performance of tcp by increasing initcwnd. I have understood how to do this.
we can use command below to increase this parameter.
# ip route change default via 192.168.1.1 dev eth0 proto static initcwnd 10

But what I didn't understand is how it works? I mean adding it to default route, how it will tell server that your congestion window is increased from 10 to 20 you can send min(20, initrwnd).

Please help me to understand it.

[Rick Jones]

Post by s***@gmail.com
I want to increase performance of tcp by increasing initcwnd. I have
understood how to do this.

Your connections are short-lived then I presume? And have > 10 TCP
segments' worth of data to send at the beginning?

Post by s***@gmail.com
we can use command below to increase this parameter.
# ip route change default via 192.168.1.1 dev eth0 proto static initcwnd 10
But what I didn't understand is how it works? I mean adding it to
default route, how it will tell server that your congestion window
is increased from 10 to 20 you can send min(20, initrwnd).

I presume you are running Linux, it would be best though since this is
a "generic" newsgroup, to state that explicitly.

TCP looks at the route to pick some of its settings. If it finds an
initcwnd setting in the route it will be using to reach the remote
destiation, it will use that rather than the default.

Your command example is (IIRC) setting the initial congestion window
to 10 segments, not 20. I cannot recall if you will need to re-start
applications after making the change. For "server" applications with
TCP LISTEN endpoints it would probably not hurt to restart them.

rick jones