From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-24-ewr.dyndns.com (mxout-123-ewr.mailhop.org [216.146.33.123]) by lists.bufferbloat.net (Postfix) with ESMTP id 19AEA2E02C5 for ; Fri, 18 Mar 2011 11:39:08 -0700 (PDT) Received: from scan-22-ewr.mailhop.org (scan-22-ewr.local [10.0.141.244]) by mail-24-ewr.dyndns.com (Postfix) with ESMTP id 6B2575CE7D4 for ; Fri, 18 Mar 2011 18:39:08 +0000 (UTC) X-Spam-Score: 0.0 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 213.165.64.23 Received: from mailout-de.gmx.net (mailout-de.gmx.net [213.165.64.23]) by mail-24-ewr.dyndns.com (Postfix) with SMTP id 714FC5CE4D4 for ; Fri, 18 Mar 2011 18:39:03 +0000 (UTC) Received: (qmail invoked by alias); 18 Mar 2011 18:39:02 -0000 Received: from unknown (EHLO srichardlxp2) [213.143.107.142] by mail.gmx.net (mp067) with SMTP; 18 Mar 2011 19:39:02 +0100 X-Authenticated: #20720068 X-Provags-ID: V01U2FsdGVkX19A6ikQ3XlAkiILou1ParBHFDo7g9aIBnm34iKb9g zZzV+Whwmzbk8u Message-ID: From: "Richard Scheffenegger" To: "Fred Baker" References: <4D7F4121.40307@freedesktop.org><20110315175942.GA10064@goldfish><1300212877.2087.2155.camel@tardy><20110315183111.GB2542@tuxdriver.com><29B06777-CC5F-4802-8727-B04F58CDA9E3@gmail.com><20110315205146.GF2542@tuxdriver.com><219C7840-ED79-49EA-929D-96C5A6200401@gmail.com><20110315151946.31e86b46@nehalam><1300228592.2087.2191.camel@tardy><1300229578.2565.29.camel@edumazet-laptop><87fwqo54n7.fsf@cruithne.co.teklibre.org><823E2A7B-4F46-4159-8029-BD3B075CC4CE@gmail.com><87bp1b6fo0.fsf@cruithne.co.teklibre.org><87bp1b4yh4.fsf@cruithne.co.teklibre.org> <35010A85-C5A4-4133-8707-4E114C65A8C6@gmail.com> <3F2F5E9B-C710-4C2F-AF99-CDF7C314A50A@cisco.com> Date: Fri, 18 Mar 2011 19:30:53 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 X-Y-GMX-Trusted: 0 Cc: Stephen Hemminger , bloat Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCPflavours - timestamps? 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: Fri, 18 Mar 2011 18:39:09 -0000 How about trying to push for a default, that the logical egress buffers are limited to say 90% of the physical capacity, and only ECN-enabled flows may use the remaining 10% when they get marked... Someone has to set an incentive for using ECN, unfortunately... Richard ----- Original Message ----- From: "Fred Baker" To: "Richard Scheffenegger" Cc: "Stephen Hemminger" ; "bloat" Sent: Thursday, March 17, 2011 1:18 PM Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCPflavours - timestamps? On Mar 17, 2011, at 5:05 AM, Fred Baker wrote: > I'm very much in favor of ECN, which in all of the tests I have done has > proven very effective at limiting queues to the knee. I'm also in favor of > delay-based TCPs like CalTech FAST and the Hamilton and CAIA models; FAST > tunes to having a small amount of data continuously in queue at the > bottleneck, and Hamilton/CAIA tunes to a small bottleneck. The problem > tends to be that the "TCP Mafia" - poorly named, but a smallish set of > people who actually control widely-used TCP implementations - tend to very > much believe in the loss-based model, in part because of poor performance > from past delay-based implementations like Vegas and in part due to IPR > concerns. Also, commercial interests like Google are pushing very hard for > fast delivery of content, which is what is behind Linux' recent change to > set the initial window segments. I didn't say, and should have said: I'm also in favor of AQM in any form; I prefer marking to dropping, but both are signals to the end system. The issue is that we need the right mark/drop rate, and the algorithms are neither trivial nor (if the fact that after 20+ years Van and Kathy haven't yet published a red-lite paper they're happy with is any indication) well documented in the general case.=