From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-11-iad.dyndns.com (mxout-235-iad.mailhop.org [216.146.32.235]) by lists.bufferbloat.net (Postfix) with ESMTP id D98EC2E0101 for ; Tue, 1 Mar 2011 07:37:41 -0800 (PST) Received: from scan-11-iad.mailhop.org (scan-11-iad.local [10.150.0.208]) by mail-11-iad.dyndns.com (Postfix) with ESMTP id 4B261171A35 for ; Tue, 1 Mar 2011 15:37:01 +0000 (UTC) X-Spam-Score: -4.0 (----) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 135.245.0.37 Received: from ihemail3.lucent.com (ihemail3.lucent.com [135.245.0.37]) by mail-11-iad.dyndns.com (Postfix) with ESMTP id 0E33F171A2E for ; Tue, 1 Mar 2011 15:36:59 +0000 (UTC) Received: from usnavsmail1.ndc.alcatel-lucent.com (usnavsmail1.ndc.alcatel-lucent.com [135.3.39.9]) by ihemail3.lucent.com (8.13.8/IER-o) with ESMTP id p21FaxrE024468 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 1 Mar 2011 09:36:59 -0600 (CST) Received: from USNAVSXCHHUB03.ndc.alcatel-lucent.com (usnavsxchhub03.ndc.alcatel-lucent.com [135.3.39.112]) by usnavsmail1.ndc.alcatel-lucent.com (8.14.3/8.14.3/GMO) with ESMTP id p21FaweE006343 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NOT) for ; Tue, 1 Mar 2011 09:36:58 -0600 Received: from [135.222.104.118] (135.3.63.241) by USNAVSXCHHUB03.ndc.alcatel-lucent.com (135.3.39.112) with Microsoft SMTP Server (TLS) id 8.3.106.1; Tue, 1 Mar 2011 09:36:58 -0600 Message-ID: <4D6D1299.9010505@Alcatel-Lucent.com> Date: Tue, 1 Mar 2011 10:36:57 -0500 From: Jim Gettys Organization: Bell Labs User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: References: <1298930176.15371.51.camel@amd.pacdat.net> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.57 on 135.245.2.37 X-Scanned-By: MIMEDefang 2.64 on 135.3.39.9 X-Mailman-Approved-At: Tue, 01 Mar 2011 08:05:27 -0800 Subject: Re: [Bloat] Usage Based Billing - It's All About Perceived Congestion X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Mar 2011 15:37:42 -0000 On 03/01/2011 08:57 AM, Steve Bauer wrote: > On Mon, Feb 28, 2011 at 4:56 PM, richard wrote: >> The result is: >> http://digital-rag.com/article.php/All-About-Perceived-Congestion-UBB >> It's aimed at the public and non-technical so allow me a few missing >> things in the explanations :) > > Hi Richard, > > You recommended to your readers: > > "You want to bug your ISP to turn off any/all "helper" buffering in > your modem that purports to "increase upload speed for short periods" > since this is buffering and part of the problem." > > I am assuming you intended that to apply to Powerboost. Based upon my > understanding of various implementations of Powerboost, > turning it off would *not* help with latency under load simply > because the buffer sizes are fixed in today's cable modems. > > So these issues are orthogonal. There are certainly > problems, but turning off Powerboost isn't part of the fix. > > Indeed, turning Powerboost off could make the problem worse. A > buffer that would otherwise have drained if Powerboost was in effect, > would be more likely to have a queue of packets sitting in it adding > additional latency to later arrivals. Again, my key assumption is > that disabling Powerboost simply doesn't change the buffer size. > > As always, happy to be proved wrong. :-) > I think you are correct, Steve, and turning it off will just make the situation worse. At the moment, I think these buffers are static in these technologies; turning off Powerboost or equivalent features will just make the situation worse. We're going to have to be adaptable to variable bandwidth anyway. AQM is ultimately the only solution. - Jim