From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mho-01-ewr.mailhop.org (mho-03-ewr.mailhop.org [204.13.248.66]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id A554521F1C8 for ; Fri, 21 Dec 2012 09:06:08 -0800 (PST) Received: from c-24-4-217-203.hsd1.ca.comcast.net ([24.4.217.203] helo=kmnmba.local) by mho-01-ewr.mailhop.org with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.72) (envelope-from ) id 1Tm62w-000IrK-6P; Fri, 21 Dec 2012 17:06:07 +0000 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 24.4.217.203 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX18D2TylIMjypp/N0OnHQjsBy1t+IxLQ6zY= Message-ID: <50D496FB.5090409@pollere.com> Date: Fri, 21 Dec 2012 09:06:03 -0800 From: Kathleen Nichols User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: codel@lists.bufferbloat.net References: In-Reply-To: X-Enigmail-Version: undefined Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Codel] R: Making tests on Tp-link router powered by Openwrt svn X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Dec 2012 17:06:08 -0000 On 12/21/12 2:32 AM, Dave Taht wrote: > On Fri, Dec 21, 2012 at 5:19 AM, Alessandro Bolletta > wrote: ... >> Also, i tried to decrease interval and target options in order to obtain a >> latency, for connections estabilished while upload is flowing, lower that 5 >> ms. >> >> So i set target at 2ms and interval to 5ms. > > You are misunderstanding target and interval. These control the > algorithm for determining when to drop. interval is set to 100ms by > default as to try to find a good estimate for the RTT, and target to > 5ms as to have a goal for a maximum delay to aim for. These values > work well down to about 4Mbits, at which point we have been bumping > target up in relation to how long it takes to deliver a packet. A > value I've been using for target at 1Mbit has been 20, as it takes > 13ms to deliver a large packet. > Dave, Thanks for clarifying the target and interval. The notion of using a 2ms target and a 5ms interval boggles the mind and is precisely why we were looking for parameters that the user didn't have to fiddle. Of course, it has to be running in the location of the actual queue! I don't understand why you are lowering the target explicitly as the use of an MTU's worth of packets as the alternate target appeared to work quite well at rates down to 64kbps in simulation as well as in changing rates. I thought Van explained this nicely in his talk at IETF. Kathie