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Re: [quicwg/base-drafts] No RTT samples, no persistent congestion (#3889)

mjoras <notifications@github.com> Wed, 22 July 2020 05:30 UTC

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Date: Tue, 21 Jul 2020 22:30:43 -0700
From: mjoras <notifications@github.com>
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Subject: Re: [quicwg/base-drafts] No RTT samples, no persistent congestion (#3889)
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FWIW this is what mvfst (and perhaps others?) has been doing since persistent congestion was implemented, since at the time it seemed silly to calculate the window using the initial RTT. However, at the time we still had the handshake timeout and so persistent congestion did not even apply to initial and handshake packets (see #2649). 

More recently our deployment has relied on PTOs for the handshake and thus this check, and there are no obvious problems with it on the Internet. I am in favor of this change even if it is perhaps not exhaustive in its coverage of unlikely pathological cases.

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