From: Sebastian Moeller <moeller0@gmx.de>
To: Jonathan Morton <chromatix99@gmail.com>
Cc: bloat <bloat@lists.bufferbloat.net>,
ECN-Sane <ecn-sane@lists.bufferbloat.net>
Subject: Re: [Ecn-sane] The curious case of "cursed-ECN" steam downloads
Date: Mon, 04 Sep 2023 09:14:21 +0200 [thread overview]
Message-ID: <8AE33E95-311F-4F9A-8940-D92F2556F661@gmx.de> (raw)
In-Reply-To: <49DF744B-E60F-47CA-AF57-F2C5D42B9244@gmail.com>
Hi Jonathan
On 4 September 2023 00:36:03 CEST, Jonathan Morton <chromatix99@gmail.com> wrote:
>> On 3 Sep, 2023, at 9:54 pm, Sebastian Moeller via Ecn-sane <ecn-sane@lists.bufferbloat.net> wrote:
>>
>> B) Excessive ECT(1) marking (this happened with a multi-GB download)
>
>This *could* be a badly configured middlebox attempting to apply a DSCP, but clobbering the entire TOS byte instead of the (left justified) DSCP field.
[SM] Mmmh, would that likely be DSCP decimal 1, aka LE? Or someone mapping e.g. a 3bit VLAN priority PCP directly onto the TOS field? What puzzles me is that from the same IPv6 I got one more data flow, 182 MB using ECT(0) and ECN... odd...
>Apparently Comcast just found a whole raft of these in their own network as part of rolling out L4S support. Funny how they didn't notice them previously.
[SM] In retrospect re-dedicating bits out of an already used header field might have been a bit optimistic....
Regards
Sebastian
>
> - Jonathan Morton
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
prev parent reply other threads:[~2023-09-04 7:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-03 18:54 Sebastian Moeller
2023-09-03 22:36 ` Jonathan Morton
2023-09-04 7:14 ` Sebastian Moeller [this message]
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