From owner-freebsd-ipfw@FreeBSD.ORG  Sun Jul 27 08:57:36 2003
Return-Path: <owner-freebsd-ipfw@FreeBSD.ORG>
Delivered-To: freebsd-ipfw@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 8DB2E37B404
	for <freebsd-ipfw@freebsd.org>; Sun, 27 Jul 2003 08:57:36 -0700 (PDT)
Received: from xorpc.icir.org (xorpc.icir.org [192.150.187.68])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 7CB2E43F75
	for <freebsd-ipfw@freebsd.org>; Sun, 27 Jul 2003 08:57:35 -0700 (PDT)
	(envelope-from rizzo@xorpc.icir.org)
Received: from xorpc.icir.org (localhost [127.0.0.1])
	by xorpc.icir.org (8.12.8p1/8.12.3) with ESMTP id h6RFvZkN089269;
	Sun, 27 Jul 2003 08:57:35 -0700 (PDT)
	(envelope-from rizzo@xorpc.icir.org)
Received: (from rizzo@localhost)
	by xorpc.icir.org (8.12.8p1/8.12.3/Submit) id h6RFvYHm089268;
	Sun, 27 Jul 2003 08:57:34 -0700 (PDT)
	(envelope-from rizzo)
Date: Sun, 27 Jul 2003 08:57:34 -0700
From: Luigi Rizzo <rizzo@icir.org>
To: Mark Hannon <markhannon@optusnet.com.au>
Message-ID: <20030727085734.A89225@xorpc.icir.org>
References: <3F212BF7.4060602@optusnet.com.au>
	<20030725103814.A54554@xorpc.icir.org> <3F23ABF3.1020905@optusnet.com.au>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.2.5.1i
In-Reply-To: <3F23ABF3.1020905@optusnet.com.au>;
	from markhannon@optusnet.com.au on Sun, Jul 27, 2003 at 08:39:47PM +1000
cc: freebsd-ipfw@freebsd.org
Subject: Re: using dummynet to simulate modem, dsl, etc
X-BeenThere: freebsd-ipfw@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: IPFW Technical Discussions <freebsd-ipfw.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw>,
	<mailto:freebsd-ipfw-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-ipfw>
List-Post: <mailto:freebsd-ipfw@freebsd.org>
List-Help: <mailto:freebsd-ipfw-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw>,
	<mailto:freebsd-ipfw-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 27 Jul 2003 15:57:37 -0000

On Sun, Jul 27, 2003 at 08:39:47PM +1000, Mark Hannon wrote:
> For those that are interested ... the following script and test results 
> were obtained.  My
> reasonings for the delay etc are partially included in the perl script. 
...
>   # add serilization of 40 octet ACK to upsteam delay
>   $us_serial_delay = (40 * 8 ) / $$this{us_bw};
...
>   # add serilization of MTU octet data to downstream delay
>   $ds_serial_delay = ($$this{mtu} * 8 ) / $$this{ds_bw};

why are you adding this extra delay ? dummynet already does that --
a packet only comes out of a pipe after what you call the "serialization"
delay (of the packet itself and any other packet queued in front of
it).

	cheers
	luigi