Re: [quicwg/base-drafts] Should kPersistentCongestionThreshold be 2 or 3? (#2556)

Praveen Balasubramanian <> Sat, 06 April 2019 01:26 UTC

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From: Praveen Balasubramanian <>
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Subject: Re: [quicwg/base-drafts] Should kPersistentCongestionThreshold be 2 or 3? (#2556)
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Well the problem with those fixed constants is that they don't work in DC for example. This has been a big pain point with TCP where we apply different minrto configs for DC and Internet. I actually liked the current QUIC definition of persistent congestion because it was dependent on actual path RTT than on some fixed value. @janaiyengar the value is not 3*PTO because there is exponential doubling? Even if max_ack_Delay is advertised as 0 by receiver then QUIC is effectively declaring persistent congestion after Srtt + 2*Srtt + 4*Srtt? So 5 * Srtt and that seems long enough?

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