From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Bloniarz Subject: [PATCH iproute2] document initcwnd Date: Wed, 05 May 2010 21:37:40 -0400 Message-ID: <4BE21D64.4040600@athenacr.com> References: <4BE171EC.20904@athenacr.com> <4BE1DB82.2030403@athenacr.com> <20100505150343.0c09c6ba@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: dormando , netdev@vger.kernel.org, Rick Jones , shemminger@osdl.org To: Stephen Hemminger Return-path: Received: from sprinkles.athenacr.com ([64.95.46.210]:62627 "EHLO sprinkles.inp.in.athenacr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751846Ab0EFBhw (ORCPT ); Wed, 5 May 2010 21:37:52 -0400 In-Reply-To: <20100505150343.0c09c6ba@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: Stephen Hemminger wrote: > On Wed, 05 May 2010 16:56:34 -0400 > Brian Bloniarz wrote: > >> dormando wrote: >>>> This sounds like TCP slow start. >>>> >>>> http://en.wikipedia.org/wiki/Slow-start >>>> >>>> As far as tunables you might want to play with the initcwnd route >>>> flag (see "ip route help") >>> Ah, yes, initcwnd was it. I'm well aware of TCP Congestion control / slow >>> start / etc. However I couldn't find the damn tunable for it :) >> Documenting the flag in ip(8) might increase its visibility >> a little. I don't see it documented in the iproute2 git head, >> though it shows up on http://linux.die.net/man/8/ip somehow. >> >> Stephen, do you know why that is? > > No one sent me an official patch to change it? Mention initcwnd in ip(8). Text taken from doc/ip-cref.tex. Signed-off-by: Brian Bloniarz diff --git a/man/man8/ip.8 b/man/man8/ip.8 index a5d2915..777a0a7 100644 --- a/man/man8/ip.8 +++ b/man/man8/ip.8 @@ -211,7 +211,9 @@ replace " | " monitor " } " .B realms .IR REALM " ] [ " .B rto_min -.IR TIME " ]" +.IR TIME " ] [ " +.B initcwnd +.IR NUMBER " ]" .ti -8 .IR TYPE " := [ " @@ -1561,6 +1563,13 @@ the clamp for congestion window. It is ignored if the flag is not used. .TP +.BI initcwnd " NUMBER " "(2.5.70+ only)" +Initial congestion window size for connections to this destination. +Actual window size is this value multiplied by the MSS +(``Maximal Segment Size'') for same connection. The default is +zero, meaning to use the values specified in RFC2414. + +.TP .BI advmss " NUMBER " "(2.3.15+ only)" the MSS ('Maximal Segment Size') to advertise to these destinations when establishing TCP connections. If it is not given,