From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-01-iad.dyndns.com (mxout-154-iad.mailhop.org [216.146.32.154]) by lists.bufferbloat.net (Postfix) with ESMTP id DE3FF2E02FC for ; Wed, 9 Feb 2011 16:51:12 -0800 (PST) Received: from scan-02-iad.mailhop.org (scan-02-iad.local [10.150.0.207]) by mail-01-iad.dyndns.com (Postfix) with ESMTP id EAC506E152 for ; Thu, 10 Feb 2011 00:51:10 +0000 (UTC) X-Spam-Score: 0.0 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 204.13.248.72 Received: from mho-02-ewr.mailhop.org (mho-02-ewr.mailhop.org [204.13.248.72]) by mail-01-iad.dyndns.com (Postfix) with ESMTP id 965386E24A for ; Thu, 10 Feb 2011 00:51:10 +0000 (UTC) Received: from [12.133.183.34] (helo=kmnmba.local) by mho-02-ewr.mailhop.org with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.72) (envelope-from ) id 1PnKkY-000MXa-96; Thu, 10 Feb 2011 00:51:10 +0000 X-Mail-Handler: MailHop Outbound by DynDNS X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/mailhop/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX18SZJeLfpqeq6AemtzqBjMvtyjP4RjVi98= Message-ID: <4D53367A.7030109@pollere.com> Date: Wed, 09 Feb 2011 16:51:06 -0800 From: Kathleen Nichols User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7 MIME-Version: 1.0 To: bloat@lists.bufferbloat.net X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: [Bloat] Pointer to Van's Queue Rant and a small plea on AQMs 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: Thu, 10 Feb 2011 00:51:13 -0000 I've read through the posts here and Jim's slides and this is a great topic. I hope progress is made. I thought I'd supply a pointer to a talk (a rant) Van gave in July of 06. I believe he reused some of this in another talk last year, but here it is: http://pollere.net/Pdfdocs/QrantJul06.pdf Also, as someone who spent a lot of time examining the dysfunctionality of 93 RED and various changes Van came up with in response to the problems: examine any AQM very carefully. It's likely not working the way you think it is. What I learned is that almost anything works with nicely behaved long-lived TCPs and that almost nothing works well with mixtures of mice and elephants. It's also instructive to examine what is really happening when your AQM drops packets. We found that 93 RED spent a lot of time doing what we called "forced drops" which means you are in the "drop everything" part of your control law. What we would find with 93 RED were a bunch of back to back drops. There's tons of stuff on this in our unfinished "RED in a different light" paper, but look at the first 10 slides or so of http://pollere.net/Pdfdocs/bcit_6.2001.pdf and you'll see some of it without wading through a lot of boring prose. So, please, please, don't make a "fix" that is perhaps worse than the original problem. Kathie (also known as "Van's wife Kathy")