Re: [tsvwg] draft minutes from interim

Bob Briscoe <> Sat, 07 March 2020 16:03 UTC

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To: Jonathan Morton <>
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From: Bob Briscoe <>
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Subject: Re: [tsvwg] draft minutes from interim
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For all L4S code, as said many times, pls always see links from the L4S 
landing page.

Also, normally, if someone is really interested in using some code and 
cannot find it, they just ask.

See inline for specifics...

On 07/03/2020 08:50, Jonathan Morton wrote:
>> On 5 Mar, 2020, at 5:04 am, Wesley Eddy <> wrote:
> Following up on this point from the minutes:
>> - Bob says all code has been available for some time.
> We had checked on the morning of the call to find that no commits had apparently been made to the previously publicised L4S codebase since November.  Nevertheless, the L4S team's presentations and commentary appeared to rely on new work which clearly post-dated that.  It was subsequently established that the paced-chirping and classic-detection code in particular had *not* yet been published anywhere, and we have also determined that the queue-protection code is not implemented in the public Linux version of the DualQ qdisc.
==Paced Chirping==
Paced Chirping has been published code since Mar 2019 at least (when we 
explained it at netdev). The link was in the netdev presentation, video, 
paper, etc. as well as off the L4S landing page, as well as IRTF iccrg 
presentations, mailing lists, etc:

The reason the Paced Chirping repo is separate from TCP Prague is that 
it's intended to be useful for any congestion control (it solely uses 
delay), altho you'll probably have to do some work to integrate it into 
each CC.

Under there, you'll find that, in Feb Joakim integrated it into TCP 
Prague (rather than DCTCP):

==Classic ECN AQM detection==
As I said during the presentation, the code was not quite available for 
the interim, but we were going to publish it shortly. Olivier is now 
testing its inclusion in an integrated version of TCP Prague. And we are 
preparing publication of a large set of test results, so they should be 
rather more self-explanatory than they are right now.


> Since these appear to be important components of the L4S system, can you point us towards where this code is available to evaluate?
>   - Jonathan Morton

Bob Briscoe