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[tsvwg] new tests of L4S RTT fairness and intra-flow latency

Pete Heist <pete@heistp.net> Thu, 12 November 2020 20:31 UTC

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From: Pete Heist <pete@heistp.net>
To: tsvwg IETF list <tsvwg@ietf.org>
Date: Thu, 12 Nov 2020 21:31:12 +0100
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Subject: [tsvwg] new tests of L4S RTT fairness and intra-flow latency
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Hi,

We have posted some new tests of L4S here:

https://github.com/heistp/l4s-tests

These tests cover two-flow fairness in several qdiscs with different
path RTTs per-flow, and transient behavior in fq_codel queues.

The results raise some concerns about a bias in favor of L4S flows in
DualPI2 queues, throughput imbalances between flows with different path
RTTs, and intra-flow latency spikes upon rate reductions in fq_codel.
The repo above contains a walk-through of the key findings, and links
to more results in the Appendix.

Regards,
Pete

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