From owner-freebsd-stable@FreeBSD.ORG  Tue May 12 21:31:13 2009
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id CEB6A1065698
	for <freebsd-stable@freebsd.org>; Tue, 12 May 2009 21:31:13 +0000 (UTC)
	(envelope-from freebsd-stable@m.gmane.org)
Received: from ciao.gmane.org (main.gmane.org [80.91.229.2])
	by mx1.freebsd.org (Postfix) with ESMTP id 88E608FC08
	for <freebsd-stable@freebsd.org>; Tue, 12 May 2009 21:31:13 +0000 (UTC)
	(envelope-from freebsd-stable@m.gmane.org)
Received: from list by ciao.gmane.org with local (Exim 4.43)
	id 1M3zZA-0005K1-Gj
	for freebsd-stable@freebsd.org; Tue, 12 May 2009 21:31:12 +0000
Received: from cpe-65-189-186-49.columbus.res.rr.com ([65.189.186.49])
	by main.gmane.org with esmtp (Gmexim 0.1 (Debian))
	id 1AlnuQ-0007hv-00
	for <freebsd-stable@freebsd.org>; Tue, 12 May 2009 21:31:12 +0000
Received: from dsamms by cpe-65-189-186-49.columbus.res.rr.com with local
	(Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00
	for <freebsd-stable@freebsd.org>; Tue, 12 May 2009 21:31:12 +0000
X-Injected-Via-Gmane: http://gmane.org/
To: freebsd-stable@freebsd.org
From: David Samms <dsamms@nw-ds.com>
Date: Tue, 12 May 2009 17:31:01 -0400
Lines: 30
Message-ID: <4A09EA95.7050800@nw-ds.com>
References: <guccc2$8b4$1@ger.gmane.org> <4A09DEF1.2010202@delphij.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Complaints-To: usenet@ger.gmane.org
X-Gmane-NNTP-Posting-Host: cpe-65-189-186-49.columbus.res.rr.com
User-Agent: Thunderbird 2.0.0.21 (X11/20090429)
In-Reply-To: <4A09DEF1.2010202@delphij.net>
Sender: news <news@ger.gmane.org>
Subject: Re: TCP differences in 7.2 vs 7.1
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 May 2009 21:31:14 -0000

Xin LI wrote:
> Hi David,
> 
> David Samms wrote:
>> After upgrading to 7.2 (amd64) some customers complained of very poor
>> bandwidth.  Upon investigation all the effected customers were ATT DSL
>> clients located all over the USA, not in a single city, nor were other
>> ISPs effected.  The server is a Supermicro with  dual (quad core)
>> processors with a single Intel fxp network card on a 100mbit connection.
> 
> Could you please try if this would help:
> 
> 	sysctl net.inet.tcp.tso=0
> 
> Cheers,
> - --
> Xin LI <delphij@delphij.net>	http://www.delphij.net/
> FreeBSD - The Power to Serve!

Xin LI,

Thank you for your help.

Setting sysctl net.inet.tcp.tso=0 resolved the issue completely.   What 
does sysctl net.inet.tcp.tso=0 do?  Where can I read more about the 
option?  I captured tcpdumps of a single file transfer to 7.1, 7.2 and 
7.2 with sysctl net.inet.tcp.tso=0, but they are to large to attach to 
this list.  Let me know if you are interested in viewing the dump files.

Thanks again for your assistance!