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 1D9FF3B2A3 for ; Fri, 27 Jan 2017 19:26:09 -0500 (EST) Received: by mail-lf0-x234.google.com with SMTP id x1so83296396lff.0 for ; Fri, 27 Jan 2017 16:26:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=bXv3YozuoEzh4aivVQNGCZX/PNcD8mkKeIlueUqTspM=; b=mtj0BQRGb6UIJUBEbI3uxMkexZy55B0KEUeKs60Nac8B9z1l87et00PGaNMMg/lFLI LftqOVtyIxbN7Lo+s5Rq/QaN6SiIJLt2LTtdDh1MKDzqknPRTih1k4BeQu50wZZUt2Ne lZFVOc4lYF1N1fBj9YFYvrIBuiXdYyMN3goqq4tjFqAUA9eGvonboNzj1J91YUJhuByz RASrK/FkFLbpJyijNOUtPs7SVORq2qxBxrRMZMNdj1slZ87FKU2AL1PzxrnkI0oJIPKY 8nOuQYQKB20RIZ/8s6u/lBlqTAeGZpOSjuD060Ah6DhWjB/M4WE4AEXyr1WmkcR1lTFk 2rsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=bXv3YozuoEzh4aivVQNGCZX/PNcD8mkKeIlueUqTspM=; b=Y9xL3lCYBrWyah+w3DgN9CsMIE44eXWCqXKhYDrn2w5/zqgCjnUKLB36F0FiUbklKH 2WCOCzfWFlm4ODVU6m7KIpQ+HvPTbzQ8mLTnZ0VYZ49b7HL+qldI7LQGraDKYEKKckNF jqxr88iAAqAIcnQz5oN4eYGliZl7o/0WYd40IbvHyqj2IDZFAGQrzy+/EkhCSltSb5U9 bkzZF30yXuqRXJzZAmFXEeFc2iJd6JkmVzoNmFjtHMkp0brdtker0PjQSLt+dIrucrfE nqJpxWCyAijiIKdN3H7lZQT/3emybjnKefjzb57A45Ka4anFQbPCuzHH531rqEthWH3e hoWQ== X-Gm-Message-State: AIkVDXIpKsDKIGSL25okRikOvhvMzP6KSVGz2xdmlXHjSwDwDGuXQgZtCQPkT3Y+/ypjViVofednIB6Gdoow7A== X-Received: by 10.25.21.96 with SMTP id l93mr3524272lfi.136.1485563167558; Fri, 27 Jan 2017 16:26:07 -0800 (PST) MIME-Version: 1.0 Received: by 10.25.198.150 with HTTP; Fri, 27 Jan 2017 16:26:06 -0800 (PST) In-Reply-To: References: From: Benjamin Cronce Date: Fri, 27 Jan 2017 18:26:06 -0600 Message-ID: To: Dave Taht Cc: bloat Content-Type: multipart/alternative; boundary=001a11406c84e4d4ab05471ca022 Subject: Re: [Bloat] Steam's TCP analysis 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: Sat, 28 Jan 2017 00:26:09 -0000 --001a11406c84e4d4ab05471ca022 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Now that I think of it, since TCP wants a minimum of two un-acked packets, you can just reduce the rate of your ACKs to keep the sender from flooding. Total hack of course. It's really a packet-pacing issue. On Fri, Jan 27, 2017 at 6:11 PM, Benjamin Cronce wrote: > In the past I've seen issues with Windows Updates because the CDN was 1 m= s > away. TCP wants to have 2 segments in flight, resulting in a non-responsi= ve > TCP stream below 13Mb/s. CDNs with low RTTs cause cause issues with low > bandwidth connections. Not only does DSL tend to have a low first hop > latency, it also tends to have less bandwidth than cable, making it a pri= me > victim for on-site CDNs. > > I just attempted to install a game(about 1GiB) from Steam and it quickly > made about 20 connections to my ISP's on-site CDN. Even if you assume a > 10ms ping for someone with DSL, that's a minimum of about 1.3Mb/s per TCP > steam. Below that, TCP becomes unresponsive to congestion. 20 connections > times 1.3Mb/s is 26Mb/s of packet flooding power. > > On Jan 27, 2017 10:15 AM, "Dave Taht" wrote: > >> All over the net I hear of the bloated horrors steam and windows 10 >> updates are inflicting on people, and several saying that inbound >> shaping isn't helping. I finally got two captures of a steam download >> here: >> >> https://github.com/tohojo/sqm-scripts/issues/43#issuecomment-275281826 >> >> And aside from some potential oddities (window, timestamp) didn't see >> anything terribly odd in the first trace I got there. Could someone >> take a look with smarter eyeballs than I have? >> >> -- >> Dave T=C3=A4ht >> Let's go make home routers and wifi faster! With better software! >> http://blog.cerowrt.org >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat >> > --001a11406c84e4d4ab05471ca022 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Now that I think of it, since TCP wants a minimum of two u= n-acked packets, you can just reduce the rate of your ACKs to keep the send= er from flooding. Total hack of course. It's really a packet-pacing iss= ue.

On Fri, = Jan 27, 2017 at 6:11 PM, Benjamin Cronce <bcronce@gmail.com>= wrote:
In the past I've seen issues with Windows Updates because the CDN was= 1 ms away. TCP wants to have 2 segments in flight, resulting in a non-resp= onsive TCP stream below 13Mb/s. CDNs with low RTTs cause cause issues with = low bandwidth connections. Not only does DSL tend to have a low first hop l= atency, it also tends to have less bandwidth than cable, making it a prime = victim for on-site CDNs.

I just attem= pted to install a game(about 1GiB) from Steam and it quickly made about 20 = connections to my ISP's on-site CDN. Even if you assume a 10ms ping for= someone with DSL, that's a minimum of about 1.3Mb/s per TCP steam. Bel= ow that, TCP becomes unresponsive to congestion. 20 connections times 1.3Mb= /s is 26Mb/s of packet flooding power.

On Jan 27, 2017 10:15 AM,= "Dave Taht" <dave.taht@gmail.com> wrote:
All over the net I hear of the bloated horrors stea= m and windows 10
updates are inflicting on people, and several saying that inbound
shaping isn't helping. I finally got two captures of a steam download here:

https://github.com/tohojo/sqm-= scripts/issues/43#issuecomment-275281826

And aside from some potential oddities (window, timestamp) didn't see anything terribly odd in the first trace I got there. Could someone
take a look with smarter eyeballs than I have?

--
Dave T=C3=A4ht
Let's go make home routers and wifi faster! With better software!
ht= tp://blog.cerowrt.org
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Bloat mailing list
Bloat@list= s.bufferbloat.net
https://lists.bufferbloat.net/listinfo/bloat

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