From owner-freebsd-stable@FreeBSD.ORG  Tue Jul 12 09:53:49 2005
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
X-Original-To: freebsd-stable@freebsd.org
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 6F8CA16A41C;
	Tue, 12 Jul 2005 09:53:49 +0000 (GMT)
	(envelope-from demizu@dd.iij4u.or.jp)
Received: from r-dd.iij4u.or.jp (r-dd.iij4u.or.jp [210.130.0.70])
	by mx1.FreeBSD.org (Postfix) with ESMTP id B8E4143D46;
	Tue, 12 Jul 2005 09:53:48 +0000 (GMT)
	(envelope-from demizu@dd.iij4u.or.jp)
Received: from localhost (h062.p048.iij4u.or.jp [210.130.48.62])
	by r-dd.iij4u.or.jp (4U-MR/r-dd) id j6C9rX3R006151;
	Tue, 12 Jul 2005 18:53:35 +0900 (JST)
Date: Tue, 12 Jul 2005 18:53:04 +0900 (JST)
Message-Id: <20050712.185304.32727687.Noritoshi@Demizu.ORG>
From: Noritoshi Demizu <demizu@dd.iij4u.or.jp>
To: Danny Braniss <danny@cs.huji.ac.il>
In-Reply-To: <E1DsGx9-0008Xc-GW@cs1.cs.huji.ac.il>
References: <E1DsGx9-0008Xc-GW@cs1.cs.huji.ac.il>
X-Mailer: Mew version 4.1 on Emacs 21 / Mule 5.0 (SAKAKI)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: David Malone <dwmalone@maths.tcd.ie>, freebsd-net@freebsd.org,
	freebsd-stable@freebsd.org, Luigi Rizzo <rizzo@icir.org>
Subject: Re: tcp troughput weirdness 
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 12 Jul 2005 09:53:49 -0000

> combining
> 	sysctl net.inet.tcp.sendspace=131072
> and
> 	sysctl net.inet.tcp.inflight.enable=0
>
> did the trick!

Congratulations!  But I wonder why the throughput of FreeBSD=>Linux
was almost equal to that of Linux=>FreeBSD.  If the settings above
improves the throughput of FreeBSD=>FreeBSD, the throughput of
FreeBSD=>Linux would also be improved with them.  Is it improved?

> now can someone remind me what inflight does?

In my understanding, it tries to estimate bandwidth-delay product and
tries to avoid injecting too much data segments into networks.
So, if it underestimates bandwidth-delay product, throughtput may be
reduced.

Regards,
Noritoshi Demizu