[quicwg/base-drafts] Update ACK generation policy (#3501)

Gorry Fairhurst <notifications@github.com> Thu, 05 March 2020 10:52 UTC

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Subject: [quicwg/base-drafts] Update ACK generation policy (#3501)
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This will update the default recommendation to ACK at least every 10th eliciting packet. This reduces ACK traffic. It also improves QUIC performance on asymmetric paths.

Related issue #3304.

QUIC ACKs are significantly larger in size than TCP ACKS (e.g. 1.5-2 times), which means additional processing overhead and link usage for all Internet paths, with a significant impact on asymmetric links, where this can also limit throughput.

Additional methods, such as the one described in https://datatracker.ietf.org/doc/draft-iyengar-quic-delayed-ack/, can be
used to modify the ACK Ratio in use-cases where further tuning is required, such as high-speed networks, or when a different congestion controller is used. Using an appropriate value for max_ack_delay, or ensuring a minimum number of ACKs per RTT (e.g 8) would mitigate the effect of ACK loss on RTT estimation and aids performance for low-rate interactive applications.
You can view, comment on, or merge this pull request online at:

  https://github.com/quicwg/base-drafts/pull/3501

-- Commit Summary --

  * Update ACK generation policy

-- File Changes --

    M draft-ietf-quic-transport.md (16)

-- Patch Links --

https://github.com/quicwg/base-drafts/pull/3501.patch
https://github.com/quicwg/base-drafts/pull/3501.diff

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