From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x234.google.com (mail-lf0-x234.google.com [IPv6:2a00:1450:4010:c07::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 81F833B2A2; Fri, 3 Jun 2016 15:34:24 -0400 (EDT) Received: by mail-lf0-x234.google.com with SMTP id k98so60835682lfi.1; Fri, 03 Jun 2016 12:34:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=J8H5GHH7AD8p5IUkdmXKypJOR+7eb3nXNVtmw6HQo7A=; b=Z8g/Iv4/wcJ1k8cx8R9N3eumYqzvx0e/C7AQ5ZNmnVnq+tIjQR1kYy4xcCCh9gAEFT hWtX3SL8k6NW0YP22Fwz5ph+mqGAUqkoYBgUkr5og08fP53S8EdiWZzB0Gt8The1Dry2 HcqUhbuR3YtDP5X8bXOfl0uUyfdGvw7vrSnd4Aj0KFcKtHxGZR7UjE2n6DTvnEobpxOZ KimU59s8OE00xk4CkyRG4fymC8ZGAGWT6AbWV90Z16AQZzbEQdp6ZlT95q63/MqlQu28 +W+cMxj1BurMsaBLat98PW5ph7/MOPH/BmvJupxwOgl/+YHmQm0AU4zLLdgdbVl/4t0I jMhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=J8H5GHH7AD8p5IUkdmXKypJOR+7eb3nXNVtmw6HQo7A=; b=O3T4P3vezgT+FmsqX1G1gbLG6HlG8D61+d4x33MgTlrufuvrM3cV7dPgu7ksok5Soz MYTMLmH2K8As5z8sCtrgL88/ddusHEiz251GFVJZLJFOSQwGiAiTRp/SyC6D7P7kUXvi 763OZmkgSD+KbeFVeow2oaLZ0y8B112GyujikOB5e7y+rFU5QC43IUIxp8fcT/colQTM xKeAUXXSc2SxfpUgKNDYpKHGsUX+10Qc7M5hwH3F1PrsfPFFb07CNnAhWxczvjIUXL6M PKfbugqh/pKPgK9MfO2K0B/Hor2tY6sJskUMGu640OVQM+8Bq+VfDTHZXp+oKKiZVCJu o3CA== X-Gm-Message-State: ALyK8tIh4giMRAUeveEMuNApzGF+NYbCOrGooLyz90EWOgm90i1ZMA8vTzherAs5FuXnaw== X-Received: by 10.46.0.221 with SMTP id e90mr1384759lji.54.1464982462752; Fri, 03 Jun 2016 12:34:22 -0700 (PDT) Received: from [192.168.100.11] (37-33-56-85.bb.dnainternet.fi. [37.33.56.85]) by smtp.gmail.com with ESMTPSA id no2sm10229lbb.5.2016.06.03.12.34.21 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 03 Jun 2016 12:34:21 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Jonathan Morton In-Reply-To: <0eb223f9-2873-7f53-c2ce-c6867ddec17c@gmail.com> Date: Fri, 3 Jun 2016 22:34:10 +0300 Cc: =?utf-8?Q?Dave_T=C3=A4ht?= , cake@lists.bufferbloat.net, codel@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <48A25043-19E2-4BB7-B634-A4003F7BE6F8@gmail.com> References: <22371476-B45C-4E81-93C0-D39A67639EA0@gmx.de> <857AEE56-E7DB-4981-B32E-82473F877139@gmail.com> <8AB0D25D-C1CA-45F1-889E-2F73CF8C44F7@gmail.com> <323AFC22-A092-4F59-8197-AF21EF73FD58@gmail.com> <274D3A0FA900FD47AA6B56991AAA32FDC5529FC8@wtl-exchp-1.sandvine.com> <574478B4.7080103@taht.net> <39F38477-A877-4C1B-9B7F-BB3358425F17@gmail.com> <0eb223f9-2873-7f53-c2ce-c6867ddec17c@gmail.com> To: Noah Causin X-Mailer: Apple Mail (2.3124) Subject: Re: [Cake] [Codel] Proposing COBALT X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jun 2016 19:34:24 -0000 > On 3 Jun, 2016, at 22:09, Noah Causin wrote: >=20 > Was the issue, where the drops and marks did not seem to occur, = resolved? Examination of packet dumps obtained under controlled conditions showed = that marking and dropping *did* occur as normal, and I got a normal = response from a local machine sending through a virtual delay line. My = Internet connection is such that extremely short RTTs never occur. However, it seems that some Internet servers I use often do not respond = as much as they should to ECN marking, resulting in excessively long = queues despite a relatively small number of flows. It rather reminds me of the symptoms one would expect to see if DCTCP = found its way onto the public Internet. And these are very popular = servers with an extremely large userbase. However it=E2=80=99s also = possible that the ECN information is somehow disappearing en route. I plan to investigate in more detail once COBALT is up and running, with = behaviour I can reason about more intuitively than the =E2=80=9Cevolved = Codel=E2=80=9D Cake has been using up to now. With COBALT integrated = into Cake, I=E2=80=99ll also be able to directly track the number of = unresponsive flows. Part of that investigation may be to enquire as to whether DCTCP is in = fact in use. If so, the TCP Prague people should be brought into the = loop, as this would constitute evidence that Codel can=E2=80=99t control = DCTCP via ECN under practical Internet conditions. - Jonathan Morton