Re: [quicwg/base-drafts] ACK-only "frames" (#763)

Martin Thomson <notifications@github.com> Wed, 06 September 2017 21:42 UTC

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Subject: Re: [quicwg/base-drafts] ACK-only "frames" (#763)
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There is more work needed here, but the point is that most congestion controllers depend heavily on feedback and if ACKs are held back by congestion control, the whole system can come crashing down.  For that reason, we need a carve-out.  If you are congestion-limited, then you can send a packet as long as it ONLY contains ACK frames.  (No word about PADDING here or its effect, that's another issue that needs clarification.)

BTW, ACKs should be identified as "retransmittable" (in the sense that the data they contain needs to be sent again somehow).  That whole retransmittable concept needs a serious rework.

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