Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I have noticed that the initial congestion window in my traces is 8920bytes~=6*1448. rfc3390 states the initial cwand should be max 4000 bytes(around 3*1448).

At first i thought it might be because i'm running my server on mac os x, so apple might have modified the tcp stack. Therefore I tried running the server on a Linux box (2.6.38) however i'm getting similar results 13032bytes=9*1448. Both server and client machines are running on a local network (via a router). Any ideas why the initial cwand is so large?

share|improve this question

1 Answer 1

There's been a few articles on increasing the initcwnd lately - the default in Linux 2.3.69 (?) has been increased to 10

There are a few rules that can affect it pre this - see http://monolight.cc/2010/12/increasing-tcp-initial-congestion-window/ for more.

I presume you're running on one of the well know private IP ranges, whether this has any difference I don't know.

From past reading Google and MS are using 10 for their public facing webservers.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.