Re: [quicwg/base-drafts] Add more context and text around ACK frequency (#3706)

Jana Iyengar <> Mon, 01 June 2020 02:32 UTC

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Date: Sun, 31 May 2020 19:32:04 -0700
From: Jana Iyengar <>
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Subject: Re: [quicwg/base-drafts] Add more context and text around ACK frequency (#3706)
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@janaiyengar commented on this pull request.

> -received packet. Limiting ACK frames avoids an infinite feedback loop of
-acknowledgements, which could prevent the connection from ever becoming idle.
-However, the endpoint acknowledges non-ACK-eliciting packets when it sends an
-ACK frame.
+### Acknowledgement Frequency
+A receiver determines how frequently to send acknowledgements in response to
+ack-eliciting packets. This determination involves a tradeoff.
+Endpoints rely on timely acknowledgment to detect loss; see Section 5 of
+{{QUIC-RECOVERY}}. Window-based congestion controllers, such as the one in
+Section 6 of {{QUIC-RECOVERY}}, rely on acknowledgments to manage their sending
+rate. In both cases, delaying acknowledgment can adversely affect performance.
+On the other hand, reducing the frequency of packets that carrying only
+acknowledgements reduces packet processing cost at both endpoints. It can also

That is a detail, which will need further substantiation. The point here is to note _some_ benefits, to point out that there are some. The specifics will depend on your particular platform.

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