Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932620Ab0GOHsi (ORCPT ); Thu, 15 Jul 2010 03:48:38 -0400 Received: from mail1.nippynetworks.com ([212.227.250.41]:32858 "EHLO mail1.nippynetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932578Ab0GOHsf (ORCPT ); Thu, 15 Jul 2010 03:48:35 -0400 Message-ID: <4C3EBD51.80406@wildgooses.com> Date: Thu, 15 Jul 2010 08:48:33 +0100 From: Ed W User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.10) Gecko/20100512 Lightning/1.0b1 Thunderbird/3.0.5 MIME-Version: 1.0 To: Tom Herbert CC: Hagen Paul Pfeifer , Rick Jones , David Miller , davidsen@tmr.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Jerry Chu , Nandita Dukkipati Subject: Re: Raise initial congestion window size / speedup slow start? References: <4C3D94E3.9080103@wildgooses.com> <4C3DD5EB.9070908@tmr.com> <20100714.111553.104052157.davem@davemloft.net> <4C3E0684.5060409@wildgooses.com> <4C3E1B54.40604@hp.com> <20100714203919.GD6682@nuttenaction> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1400 Lines: 31 On 15/07/2010 05:12, Tom Herbert wrote: > There is an Internet draft > (http://datatracker.ietf.org/doc/draft-hkchu-tcpm-initcwnd/) on > raising the default Initial Congestion window to 10 segments, as well > as a SIGCOMM paper (http://ccr.sigcomm.org/online/?q=node/621). > You guys have obviously done a lot of work on this, however, it seems that there is a case for introducing some heuristics into the choice of init cwnd as well as offering the option to go larger? An initial size of 10 packets is just another magic number that obviously works with the median bandwidth delay product on today's networks - can we not do better still? Seems like a bunch of clever folks have already suggested tweaks to the steady stage congestion avoidance, but so far everyone is afraid to touch the early stage heuristics? Also would you guys not benefit from wider deployment of ECN? Can you not help find some ways that deployment could be increased? At present there are big warnings all over the option that it causes some problems, but there is no quantification of how much and really whether this warning is still appropriate? Ed W -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/