Re: [tsvwg] [Ecn-sane] Comments on L4S drafts

Jonathan Morton <chromatix99@gmail.com> Thu, 04 July 2019 14:03 UTC

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From: Jonathan Morton <chromatix99@gmail.com>
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Date: Thu, 04 Jul 2019 17:03:06 +0300
Cc: Bob Briscoe <ietf@bobbriscoe.net>, "ecn-sane@lists.bufferbloat.net" <ecn-sane@lists.bufferbloat.net>, "tsvwg@ietf.org" <tsvwg@ietf.org>
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To: "De Schepper, Koen (Nokia - BE/Antwerp)" <koen.de_schepper@nokia-bell-labs.com>
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Subject: Re: [tsvwg] [Ecn-sane] Comments on L4S drafts
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> On 4 Jul, 2019, at 4:43 pm, De Schepper, Koen (Nokia - BE/Antwerp) <koen.de_schepper@nokia-bell-labs.com> wrote:
> 
> So conclusion:   a DualQ works exactly the same as any other single Q AQM supporting ECN !!
> Try it, and you'll see...

But that's exactly the problem.  Single queue AQM does not isolate L4S traffic from "classic" traffic, so the latter suffers from the former's relative aggression in the face of AQM activity.  This isolation is the very reason why something like DualQ is proposed, so the fact that it can be defeated into this degraded single-queue mode is a genuine problem.

May I direct you to our LFQ draft, published yesterday, for what we consider to be a much more robust approach, yet with similar hardware requirements to DualQ?  I'd be interested in hearing feedback.

 - Jonathan Morton