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Re: [quicwg/base-drafts] Remove ack_delay_exponent TP (#2670)

ianswett <notifications@github.com> Thu, 09 May 2019 15:19 UTC

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Subject: Re: [quicwg/base-drafts] Remove ack_delay_exponent TP (#2670)
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1) I think it makes slightly more sense for the receiver to specify it, since the receiver is the one setting a delayed ack alarm, but I can imagine it working ok either way.  It pairs with max_ack_delay in some ways, and that's receiver specified, so I think keeping it on the receiver side is preferable.

2) If you have a 100us RTT and >1ms timer granularity, then I think this becomes more important, not less.  In that case, you want to pace over the true RTT, not the SRTT without adjusting for max_ack_delay, because that may be 10x or more too slow.   And to second @mikkelfj point, sub-millisecond timers are now fairly common.

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