Re: [tsvwg] plan for L4S issue #29

Jonathan Morton <> Fri, 31 July 2020 18:03 UTC

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From: Jonathan Morton <>
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Date: Fri, 31 Jul 2020 21:03:00 +0300
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To: Wesley Eddy <>
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Subject: Re: [tsvwg] plan for L4S issue #29
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> On 31 Jul, 2020, at 6:41 pm, Wesley Eddy <> wrote:
> Hello, ticket #29 for the L4S documents is about classic bottleneck detection misidentifying L4S queues as classic ECN queues.
> In contrast to other issues, it doesn't seem like this should block a WGLC on the L4S drafts.
> 	• It is specific to classic bottleneck detection algorithm, which is planned to be worked on in the Prague ICCRG draft.
> 	• The result is sometimes failing to achieve the best possible L4S behavior, but doesn't seem to be an Internet safety issue.  This resulting in people turning off classic bottleneck detection would be a different issue, and something maybe the operator guidelines would address.
> 	• It seems like it can be worked on further in the course of L4S experimentation, without negative effects to others.

> So, I believe we should track this work in the ICCRG, and close the ticket here.  Please let me know in the next week if I've misunderstood any aspect of this and it should remain open.

Presently, the Prague congestion control algorithm is unsafe on the Internet without a properly functioning classic-bottleneck detection heuristic.  Additionally, the classic-bottleneck detection heuristic that has been published and demonstrated does not function properly.  This combination of facts absolutely *is* a blocker for WGLC.

Therefore, this issue should not be closed until it has been concretely addressed.

 - Jonathan Morton