From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <shemminger@vyatta.com>
Subject: Re: TCP Congestion Control Algorithms
Date: Mon, 31 Aug 2009 15:07:31 -0700
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To: Lisong Xu <lisongxu2@gmail.com>
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On Mon, 31 Aug 2009 16:10:59 -0500
Lisong Xu <lisongxu2@gmail.com> wrote:

> Hello,
> 
> Since there are multiple different TCP congestion control algorithms
> available in Linux, a Linux server may use any of them.
> 
> Is it possible for a regular user to find out the exact TCP congestion
> control algorithm used by a Linux server? For example, if I am
> downloading a file from a remote Linux server using a TCP flow, can I
> find out whether this flow is a TCP/CUBIC flow, or TCP/Newreno, or
> some other TCP protocol?
> 

No. you might be able to some nmap style guessing, but no remote
API. You can see locally on the server through /proc/sys/net