Re: [quicwg/base-drafts] compensation of ack_delay is fragile against errors (#2060)

janaiyengar <notifications@github.com> Thu, 29 November 2018 04:11 UTC

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Subject: Re: [quicwg/base-drafts] compensation of ack_delay is fragile against errors (#2060)
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In general, I think having an inflated RTT is better than a lower than actual RTT, since inflated RTT leads to a less aggressive sender and smaller than actual RTT leads to a more aggressive sender.

Admittedly, it's possible for there to be error when latest_rtt - (inflated) ack_delay > min_rtt.  That's the error that I had considered an accepted cost of using ack_delay.

It's fair to ask what should we do about a receiver that we consider might have a bad clock... I wouldn't be opposed to ignoring ack_delay entirely for the rest of the connection... I wonder if there are counter cases that I'm missing though where this ends up being too aggressive. In general, the receiver should be rounding *down* when reporting delay, not up.

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