From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-22-ewr.dyndns.com (mxout-181-ewr.mailhop.org [216.146.33.181]) by lists.bufferbloat.net (Postfix) with ESMTP id 10D2E2E00FC for ; Sun, 30 Jan 2011 17:43:14 -0800 (PST) Received: from scan-21-ewr.mailhop.org (scan-21-ewr.local [10.0.141.243]) by mail-22-ewr.dyndns.com (Postfix) with ESMTP id E26D0327D4 for ; Mon, 31 Jan 2011 01:43:13 +0000 (UTC) X-Spam-Score: 0.0 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 76.96.59.211 Received: from QMTA11.westchester.pa.mail.comcast.net (qmta11.westchester.pa.mail.comcast.net [76.96.59.211]) by mail-22-ewr.dyndns.com (Postfix) with ESMTP id A8E45327C2 for ; Mon, 31 Jan 2011 01:43:10 +0000 (UTC) Received: from omta08.westchester.pa.mail.comcast.net ([76.96.62.12]) by QMTA11.westchester.pa.mail.comcast.net with comcast id 21UP1g0050Fqzac5B1jB2X; Mon, 31 Jan 2011 01:43:11 +0000 Received: from [192.168.1.119] ([98.229.99.32]) by omta08.westchester.pa.mail.comcast.net with comcast id 21jA1g0070hvpMe3U1jAPY; Mon, 31 Jan 2011 01:43:11 +0000 Message-ID: <4D4613AD.6070800@freedesktop.org> Date: Sun, 30 Jan 2011 20:43:09 -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: bloat@lists.bufferbloat.net References: <208F592F3F104C89AA0135E5F02B2241@srichardlxp2> <4D460137.3070305@freedesktop.org> <87pqrdg9z4.fsf@cruithne.co.teklibre.org> In-Reply-To: <87pqrdg9z4.fsf@cruithne.co.teklibre.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Bloat] ECN & AQM Hall of Fame? 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: Mon, 31 Jan 2011 01:43:15 -0000 On 01/30/2011 08:03 PM, Dave Täht wrote: > >> On 01/30/2011 05:40 PM, Richard Scheffenegger wrote: >>> Hi, >>> >>> wasn't there talk about getting a Hall of Fame for networks / operators, which are using and actively supporting AQM and ECN in their administrative domain? >>> >>> I just looked at some traces to troubleshoot SMTP with GMX (german freemail/hosting provider), and noticed that they are in fact negotiating for ECN on their mail servers: >>> > > One data collection method I've been thinking about was using hooks on > network chains (netfilter) to gather statistics on the actual incidence > of ECN and SACK/DSACK. > > I have found a lot of places that negotiate ECN but have rarely seen ECN > actually get used on the path. > > We'd need an ECN hall of fame and a separate SACK related one too. > Steve Bauer has been performing a very extensive survey of ECN on the Alexa top sites; he should have results in the next few weeks, for the CAIDA workshop. Talk Title: A survey of the current state of ECN support in servers, clients, and routers Talk Abstract: Explicit congestion notification (ECN) is a key building block in a number of ongoing standardization efforts [Conex] and research projects [Alizadeh]. This paper therefore sought to survey the current state of ECN support on the Internet, updating and extending a similar survey from 2008 [Langley]. (There are a number of reasons to suspect the state of ECN support may have changed including 'server-side ECN' becoming the default on recent versions of the Linux kernel.) In the process of conducting our survey we discovered that some routers incorrectly handle the ECN bits in the IP header, namely clearing the ECT bit. Given that this is a new impediment to using ECN, we sought to carefully measure exactly where this problem occurred. While measuring ECN support to web servers is straightforward, we developed novel active/passive hybrid approaches for collecting similar measurements of paths to clients. This is important because even if some servers support ECN, if the paths to clients contain impediments to ECN usage (which we show they do) the incremental deployment of ECN is harmed. In short, ECN is no longer blocked much, but very few are actually turning it on. News when it's available... - Jim