Re: [quicwg/base-drafts] Flow Control Tuning (#3216)

ianswett <> Mon, 02 December 2019 17:43 UTC

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Subject: Re: [quicwg/base-drafts] Flow Control Tuning (#3216)
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I think we should keep this in transport.  

I think we can provide more specific guidance than we do now, including guidance to bundle flow control updates with ACK frames, but not to bundle them with every ACK frame(otherwise you end up ACK-ing ACKs, which we know is bad).  I'm biased towards marking this editorial, but we can wait for a PR to see.

Our implementation does(approximately):
1) Send an update every time 1/2 the window has been consumed
2) Double the size of the window every time two updates are sent within an RTT.

Particularly early in the connection, ideally the flow control window is 2x the peer's current congestion control window, because the CWND doubles every RTT in slow start.

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