From owner-freebsd-hackers@FreeBSD.ORG Tue Nov 2 19:48:20 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1A6B716A4CE for ; Tue, 2 Nov 2004 19:48:20 +0000 (GMT) Received: from mx1.z-axis.com (z.axis28.z.subnet.rcn.com [209.122.82.156]) by mx1.FreeBSD.org (Postfix) with ESMTP id DBE5043D53 for ; Tue, 2 Nov 2004 19:48:19 +0000 (GMT) (envelope-from justin@z-axis.com) Received: (qmail 3992 invoked by uid 89); 2 Nov 2004 19:48:19 -0000 Received: from unknown (HELO ?127.0.0.1?) (justin@209.122.82.179) by mx1.z-axis.com with SMTP; 2 Nov 2004 19:48:19 -0000 Message-ID: <4187E483.8050008@z-axis.com> Date: Tue, 02 Nov 2004 11:48:19 -0800 From: Justin Bennett Organization: Z-Axis, Ltd. User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20040910 X-Accept-Language: en-us, en MIME-Version: 1.0 To: FreeBSD Hackers References: <4187E23C.7000900@z-axis.com> <4187E38F.2070809@elischer.org> In-Reply-To: <4187E38F.2070809@elischer.org> X-Enigmail-Version: 0.86.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: ipfw pipes: theoretical speed vs. reality X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 02 Nov 2004 19:48:20 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 | | | Justin Bennett wrote: | | All, | | I have recently been setting up pipes to shape bandwidth on our local | net. | | However, unless I am missing something, the TCP overhead seems quite | large. | | If I configure the following pipe: | | $IPFW pipe 1 config bw 64Kbit/s | $IPFW add 31 pipe 1 ip from 192.168.0.1/24 to any | $IPFW add 32 pipe 1 ip from any to 192.168.0.1/24 | | The run traffic from my machine (192.168.0.2) through it, I get less | than half the expected bandwidth (3.9KB/s). I tried another test with a | 512Kbit/s pipe, and got around 30KB/s. | | I know on most ATM/FR lines, you can expect about 10% overhead, but 50% | seems high. | | When I remove the pipe, my T1 comes back to life, and I can pull the | same data at 160+KB/s. | | Am I missing something? | | | |> yes you are queuing data in both directions on the same queue, thus |> serialising it.. | |> use 2 seprarate pipes. one for each direction. Thanks. I knew it was simple, just couldn't wrap my head around it. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (MingW32) iD8DBQFBh+SDlNUG+Ne1CZMRAl4WAJ9DEaiyU9N/SPKGi6WlqdHe2qkhmwCghv7m So0IGU5OchsjXYHduNPm4C8= =ZjYx -----END PGP SIGNATURE-----