Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757828AbXJOP4L (ORCPT ); Mon, 15 Oct 2007 11:56:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755741AbXJOPzz (ORCPT ); Mon, 15 Oct 2007 11:55:55 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:51221 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752714AbXJOPzy (ORCPT ); Mon, 15 Oct 2007 11:55:54 -0400 Date: Mon, 15 Oct 2007 08:55:41 -0700 From: Stephen Hemminger To: Komuro Cc: shemminger@linux.foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [NOT VERY SAFE] [TCP]: Set initial_ssthresh default to zero in Cubic and BIC. Message-ID: <20071015085541.48ec63ae@freepuppy.rosehill> In-Reply-To: <20071015215949.50399c00.komurojun-mbn@nifty.com> References: <20071006132601.f944f461.komurojun@nifty.com> <20071014073658.d4352b8c.komurojun@nifty.com> <20071014100245.914b784a.komurojun@nifty.com> <20071014132851.8d6a9de3.komurojun@nifty.com> <20071014135356.19754635.komurojun-mbn@nifty.com> <20071015215949.50399c00.komurojun-mbn@nifty.com> Organization: Linux Foundation X-Mailer: Claws Mail 3.0.2 (GTK+ 2.10.14; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 828 Lines: 30 On Mon, 15 Oct 2007 21:59:49 +0900 Komuro wrote: > Dear shemminger > > >In which case it is zero because that is the default value. > > The default value of snd_ssthresh is 0x7fffffff, isn't it? > > [linux/net/ipv4/tcp_ipv4.c] > static int tcp_v4_init_sock(struct sock *sk) > ... > tp->snd_ssthresh = 0x7fffffff; /* Infinity */ > ... > > Best Regards > Komuro > > Yes that value means that TCP stays in slow start until the first loss. This makes TCP behave as expected in the RFC's. -- Stephen Hemminger - 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/