Discussion of explicit congestion notification's impact on the Internet
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From: Sebastian Moeller <moeller0@gmx.de>
To: Jonathan Morton <chromatix99@gmail.com>
Cc: "Dave Täht" <dave.taht@gmail.com>,
	ECN-Sane <ecn-sane@lists.bufferbloat.net>
Subject: Re: [Ecn-sane] osx ecn
Date: Tue, 27 Aug 2019 09:52:16 +0200	[thread overview]
Message-ID: <B451E6CD-B802-409E-B43B-5007F62786E1@gmx.de> (raw)
In-Reply-To: <9E5E5296-EF62-46C4-8AD5-F93D5A03BDB7@gmail.com>

Hi Jonathan,


> On Aug 27, 2019, at 09:05, Jonathan Morton <chromatix99@gmail.com> wrote:
> 
>> On 27 Aug, 2019, at 9:58 am, Sebastian Moeller <moeller0@gmx.de> wrote:
>> 
>>> 0 connection fell back to non-ECN due to excessive CE-markings
>> 
>> I wonder whether macosx would be able to gracefully survive a misclassification into a L4S/NQB queue at a dual queue AQM? What is the threshold here?
> 
> No, I don't think so.  L4S assumes the DCTCP response function which stabilises at 2 CE marks per RTT, which is still a fairly low percentage if the cwnd is high.  I doubt that would be detected as "excessive" in this context.  Also, because the RFC-3168 response to CE is much sharper, the actual marking rate will be lower, as the flow won't stay in the saturating regime where marking occurs.
> 
> - Jonathan Morton


thanks for the detailed answer.

Best Regards
	Sebastian

      reply	other threads:[~2019-08-27  7:52 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-27  2:03 Dave Taht
2019-08-27  6:47 ` Mikael Abrahamsson
2019-08-27  6:54   ` Michael Welzl
2019-08-27  7:02     ` Mikael Abrahamsson
2019-08-27 18:20       ` Dave Taht
2019-08-27 18:36     ` Dave Taht
2019-08-27 19:00       ` Michael Welzl
2019-08-28 23:29         ` Ryan Mounce
2019-08-28 23:45           ` Dave Taht
2019-08-29  0:55             ` Dave Taht
2019-08-29  3:28               ` Mikael Abrahamsson
2019-08-29  4:43                 ` Dave Taht
2019-08-29 10:30                   ` Mikael Abrahamsson
2019-08-29  8:08             ` Jonathan Morton
2019-08-29 10:39             ` Ryan Mounce
2019-08-27  6:58 ` Sebastian Moeller
2019-08-27  7:05   ` Jonathan Morton
2019-08-27  7:52     ` Sebastian Moeller [this message]

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