Re: [quicwg/base-drafts] Why min CWND of 2 instead of 1 (#3586)

ianswett <notifications@github.com> Thu, 23 April 2020 18:28 UTC

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Subject: Re: [quicwg/base-drafts] Why min CWND of 2 instead of 1 (#3586)
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@ianswett commented on this pull request.



> @@ -245,6 +245,13 @@ QUIC specifies a time-based definition to ensure one or more packets are sent
 prior to a dramatic decrease in congestion window; see
 {{persistent-congestion}}.
 
+### Increase the min congestion window to 2 packets
+
+QUIC recommends a minimum congestion window of 2 packets instead of TCP's 1.
+2 packets avoid waiting for a delayed acknowledgement and allow the PTO to
+send 2 packets instead of 1, which can be particularly important during the

I'd expect congestion collapse to be dominated by the PTO response, not the CWND.

I'm not aware of efforts to do fractional MSS in common use.  Do you have a reference for that?

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