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From: Benjamin Cronce <bcronce@gmail.com>
To: Dave Taht <dave.taht@gmail.com>
Cc: bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] Steam's TCP analysis
Date: Fri, 27 Jan 2017 18:11:52 -0600	[thread overview]
Message-ID: <CAJ_ENFFO+dF52kJmQiRFWPxkPdWn+=QG5b7YughMMrLdF+9fiw@mail.gmail.com> (raw)
In-Reply-To: <CAA93jw67=07cJXUS9kTqjvC=8i+saX_yB_QqwJQRHLHXrQ3EwQ@mail.gmail.com>

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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-responsive
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 prime
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" <dave.taht@gmail.com> 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 Täht
> 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
>

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  reply	other threads:[~2017-01-28  0:11 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-27 16:15 Dave Taht
2017-01-28  0:11 ` Benjamin Cronce [this message]
2017-01-28  0:26   ` Benjamin Cronce
2017-01-28 10:29 ` Yoshifumi Nishida

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