From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x242.google.com (mail-lf0-x242.google.com [IPv6:2a00:1450:4010:c07::242]) (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 D7CCF3B2BC; Sat, 4 Jun 2016 18:03:33 -0400 (EDT) Received: by mail-lf0-x242.google.com with SMTP id h68so10640305lfh.3; Sat, 04 Jun 2016 15:03:33 -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=Tf6rvL+YMlsJcaKZ+8jYPAWpFxtYNdjzWx/UpKk203k=; b=XZWGS2bNyt2X5T8ZbBL3/woiuEiFNeBxG2YrrNarlZ02HfBM91XWugGq0qnyRfk/vV ToXpZ7E4dJe7H5uRbaYVqGrLf5RATZ8LSgZxoyY3+ru3JccIsKC7X2IeUk33RT7MwFHs NcmkexN5Cvlwzc+4T4S/5c3KvfUBUoysP0wSp147D1UBf+3yvRJdtuMbpN43uRFSGxiD JG5PmGS3nt34feknxV0hCaIsQW/QQw88+TY8A+ib6LJ1cl3AR9dXpl2SZ7Z4OgNioee9 3LDgr+Wcrswoll+YAkHCcxzUvMh6vIiRK4pIaBoGJ+UbJs4aBCVFiA39egEo6mlF9JJw IGlw== 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=Tf6rvL+YMlsJcaKZ+8jYPAWpFxtYNdjzWx/UpKk203k=; b=VbnFvlD8BZPSafTRRP1EgptEzoR3opW2yv/ODgefzK28BB4B0UMBXpvdZZi4C6qX8p pSPzLRvzOLIUi3xQSjYd0ds6zgys0PgmR2w48zVROz1dPbWnjo8zUPPhhWIsAfqpxrvO 6D30BoRRL1YeYDKrqhru6s3wH5kbxTj+6GWc5YM5xOXrK34q8jz8c1uZBkpch+jO6uDJ 7eCPZFgIl2Ce115tHK0/9SmeMp9zpy4IsLXCyaKyxUkMq92VL3/lVS2ss+9m5sdy4j+s 2kLJNhluF/IR2lE2DMG8BXxg52dPNPchHNUlz9wyyHxfXE2AZcNDHBL9P5RIYEdHGCe0 ZS0g== X-Gm-Message-State: ALyK8tLJeHz1pqx/Ha17MRMsxVF7MLCnjqUEvCTf//CJcQz0JB/9s82m0MdFW2L2lQMHPA== X-Received: by 10.25.139.136 with SMTP id n130mr2378763lfd.203.1465077812476; Sat, 04 Jun 2016 15:03:32 -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 b8sm1105291lbc.16.2016.06.04.15.03.31 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 04 Jun 2016 15:03:31 -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: Sun, 5 Jun 2016 01:03:21 +0300 Cc: Noah Causin , Andrew McGregor , cake@lists.bufferbloat.net, "codel@lists.bufferbloat.net" Content-Transfer-Encoding: quoted-printable Message-Id: <2F1AD7A4-EEE8-4519-B2E6-75CD4784D2B2@gmail.com> References: To: Alan Jenkins X-Mailer: Apple Mail (2.3124) Subject: Re: [Cake] [Codel] Proposing COBALTLike the issues with streaming video, which are potentially addressed by the fq qdisc. I wonder how much it would help for torrents. (Avoiding bursting the entire congestion window at the start of chunk 2, using pacing). 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: Sat, 04 Jun 2016 22:03:34 -0000 > On 4 Jun, 2016, at 23:04, Alan Jenkins = wrote: >=20 > Am I right in thinking Steam uses a torrent download? No; though it is a multi-stream system, it=E2=80=99s basically HTTP = (with offset/range) plus some minor special sauce. Several files can be = fetched at once in parallel, and these separate connections are usually = to different servers. It differs from torrent swarms most fundamentally in that there is no = uploading; all the content comes from official servers. This also means = that fewer connections are needed to fill a given download pipe (usually = just one would do the trick). We=E2=80=99re at a significant disadvantage because we typically have to = apply our AQM *after* the bottleneck link in the downstream direction. = This means we have to somehow prevent senders from sending too many = packets in order to avoid inducing delay within the ISP=E2=80=99s dumb = buffers, rather than being able to buffer them smartly ourselves as a = last resort. We therefore rely on effective congestion control, with = flow-isolation being primarily a means to target the signals more = precisely. Servers which defeat our primary method of doing so (by ignoring the = copious signals saying =E2=80=9Cslow down please=E2=80=9D) are = ultimately unhelpful. But at least they are still ack-clocked. - Jonathan Morton