Subject: [tsvwg] Added new scenario to l4s-tests and updated text

From: Pete Heist <[email-masked]>
Date: Thu, 03 Dec 2020 22:28:54 +0100

Hi folks,

I pushed some updates to the l4s-tests repo, to add a new scenario, and
change some text in response to feedback:

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

* The finding "Unsafety in Tunnels Through RFC3168 Bottlenecks" was
split into "Unsafety in Shared RFC3168 Queues" and "Tunneled Non-L4S
Flows Not Protected by FQ", so as not to conflate the two. The former
was elaborated upon using data from the new Scenario 6.

* A new Scenario 6 tests Prague vs CUBIC and Reno in various single
queue RFC3168 AQMs. This puts more data behind the known issue at
https://trac.ietf.org/trac/tsvwg/ticket/16, and makes it clear that
both ECN and non-ECN flows can be starved by L4S flows in shared queues
signaled by RFC3168 AQMs.

* A Risk Assessment section was added, where we start to evaluate the
"Unsafety in Shared RFC3168 Queues" finding in terms of severity and
likelihood. Work is ongoing to flesh this section out, but we also note
that when it comes to assessing risk, the high severity observed leaves
little to no tolerance for the likelihood of it occurring.

Pete