From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x22d.google.com (mail-lf0-x22d.google.com [IPv6:2a00:1450:4010:c07::22d]) (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 A2F283B29E for ; Thu, 27 Apr 2017 00:27:36 -0400 (EDT) Received: by mail-lf0-x22d.google.com with SMTP id 75so10718316lfs.2 for ; Wed, 26 Apr 2017 21:27:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=o6zui5LyHSO68GjltpFWjq86jCuxR8Cq+aZLXeZgswE=; b=aPN1hZU//mEDSfJ+TI1mY5KxhkCPAOAPbfsjcJzd9aQuJKKqsfjrS6AS2wO6bqzZ8M GU6wnraP2hvmH6Sk+BxU0XERdzw/xggp/+8M1Z+BQOf/EqgTfJp19Ewbjw0qE4KsqcO8 mZhfFfOOK+OHCK1wAw2ZEfOa0uAneJ7ATsxNsESB82vIV9BBoP7U3Ugc9HtJu0LjjrmN 16PKJsapAHNhfq42OowFpJOCJr5BuBeIt3V72AF2my4A+4R5L37BtmmzqjDVqhgyAff2 M7jzSAfzn65tOCjZbN6Bf1g1H9/ty5U+mUsjK1AHwbMStKRd/nxNq0uMw6gaTikPpnT0 /DGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=o6zui5LyHSO68GjltpFWjq86jCuxR8Cq+aZLXeZgswE=; b=ryjLDHpO9q8AxGhzryil8FcRNV250ckMi4gfpmsp4f5H9YB4gGeMk0/3dHelR61ScQ 4eCmA7v8FJSB+nVb7XhjkSw2ZhNo3c5jwUa2+yTRg+ltSq6poB9OAMqJ6YkMIGn2+Ir8 XPf+O96pjW+jNlSKPqyqV7a+pTKRdwOMnGmokWbKQCmEiYib5jJpG0FIWdjnWI4IOE+B AhUteP31gAlmHHhkMNbpXdIYgPrCDoQW4U8m1ii7UA2N4YJEJ3oSDrHC9h3RnTTafYdB bY8uXxlnNAmdcrboxw13Tv1XsrCgQMw0M5qWugST0SRXQlthJXF8OlkZX3Hopvo3PywZ 84Sw== X-Gm-Message-State: AN3rC/50HxFYFYyiy4ABKesfl6rOHl9lOhbiMxQUEaLKMqHO71b9IYG1 Xcyp6eDfss3OBzp0AwY= X-Received: by 10.46.33.11 with SMTP id h11mr1350801ljh.57.1493267255154; Wed, 26 Apr 2017 21:27:35 -0700 (PDT) Received: from [192.168.100.12] (37-219-103-185.nat.bb.dnainternet.fi. [37.219.103.185]) by smtp.gmail.com with ESMTPSA id q84sm229879lfi.31.2017.04.26.21.27.33 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 26 Apr 2017 21:27:34 -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: Date: Thu, 27 Apr 2017 07:27:29 +0300 Cc: bloat@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <04CFC938-9B1C-40E4-AB17-C8E41BB094EB@gmail.com> References: To: cloneman X-Mailer: Apple Mail (2.3124) Subject: Re: [Bloat] Steam's download CDNs - breaking bufferbloat and inbound policers X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Apr 2017 04:27:36 -0000 > On 27 Apr, 2017, at 07:19, cloneman wrote: >=20 > I'm looking for any comments on Steam's game distribution download = system - specifically how it defeats any bufferbloat management system = I've used. =20 >=20 > It seems to push past inbound policers, exceeding them by about 40%. = That is to say, you must police steam traffic to half your line rate, = then enough capacity will remain to avoid packet loss, latency, etc. = Obviously this is too much bandwidth to reserve for practical use. >=20 > Without any inbound control, you can expect very heavy packet loss and = jitter. With fq_codel or sfq and taking the usual recommended 15% off = the table, you get improved, but still unacceptable performance in your = small flows / ping etc.=20 >=20 > The behavior can be observed by downloading any free game on their = platform. I'm trying to figure out how they've accomplished this and how = to mitigate this behavior. It operates with 20 http connections = simultaneously, which is normally not an issue (20 multiple web = downloads perform well under fq_codel and 15% reserve bandwidth)=20 Have you tried using Cake in its new ingress mode? That counts dropped = packets against the shaper, ensuring that the load they already imposed = on the link upstream of the shaper is accounted for. This is probably = impossible to implement with a separate shaper and AQM (eg. HTB + = fq_codel). I=E2=80=99ve also found that Steam responds well to ECN, at least on my = local instances, so you should turn ECN on fully on your end-hosts. I = would dearly love to see ECN on by default, but so far only Apple (of = all vendors!) has shown that level of courage. - Jonathan Morton