From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] TCP: H-TCP maxRTT estimation at startup Date: Tue, 07 Aug 2007 18:29:17 -0700 (PDT) Message-ID: <20070807.182917.101870814.davem@davemloft.net> References: <20070803105756.2f41dc25@oldman.hamilton.local> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: doug.leith@nuim.ie, netdev@vger.kernel.org To: shemminger@linux-foundation.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:58152 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S935182AbXHHB3R (ORCPT ); Tue, 7 Aug 2007 21:29:17 -0400 In-Reply-To: <20070803105756.2f41dc25@oldman.hamilton.local> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Stephen Hemminger Date: Fri, 3 Aug 2007 10:57:56 +0100 > Small patch to H-TCP from Douglas Leith. > > Fix estimation of maxRTT. The original code ignores rtt measurements > during slow start (via the check tp->snd_ssthresh < 0xFFFF) yet this > is probably a good time to try to estimate max rtt as delayed acking > is disabled and slow start will only exit on a loss which presumably > corresponds to a maxrtt measurement. Second, the original code (via > the check htcp_ccount(ca) > 3) ignores rtt data during what it > estimates to be the first 3 round-trip times. This seems like an > unnecessary check now that the RCV timestamp are no longer used > for rtt estimation. > > Signed-off-by: Stephen Hemminger Applied, thanks Stephen.