Re: [Bloat] Fwd: Identifying TCP congestion control algorithms, and measurement results

[Steve Bauer <bauer@mit.edu>]

On Wed, Mar 23, 2011 at 3:14 PM, Otto Solares <solca@guug.org> wrote:
> IW10 seems to be part now of mainline Linux since 2.6.37:
>
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=356f039822b8d802138f7121c80d2a9286976dbd

Note this patch only changed the initial *receive* window, not the
initial congestion window.

"This patch changes the default initial receive window to 10 mss
(defined constant). The default window is limited to the maximum
of 10*1460 and 2*mss (when mss > 1460).

[....]

However, an initial congestion window of 10 mss is useless unless a TCP
receiver advertises an initial receive window of at least 10 mss.
Fortunately, in the large-scale Internet experiments we found that most
widely used operating systems advertised large initial receive windows
of 64KB, allowing us to experiment with a wide range of initial
congestion windows. Linux systems were among the few exceptions that
advertised a small receive window of 6KB. The purpose of this patch is
to fix this shortcoming.
"