[Codel] D* tcp looks pretty good, on paper

Dave Taht dave.taht at gmail.com
Thu Jan 7 13:35:00 EST 2021

See: https://arxiv.org/pdf/2012.14996.pdf

Things I really like:

* they used flent
* Using "variance" as the principal signal. This is essentially one of
the great unpublished and unanalyzed improvements on the minstrel
algorithm as well
* Conventional ecn response
* outperforms bbr on variable links

Only negative so far is I haven't found any published source to it. :(

Otherwise a very promising start to a year.

"The choice of feedback mechanism between delay and packet loss has
long been a point of contention in TCP congestion control. This has
partly been resolved, as it has become increasingly evident that delay
based methods are needed to facilitate modern interactive web
applications. However, what has not been resolved is what control
should be used, with the two candidates being the congestion window
and the pacing rate. BBR is a new delay based congestion control
algorithm that uses a pacing rate as its primary control and the
congestion window as a secondary control. We propose that a congestion
window first algorithm might give more desirable performance
characteristics in situations where latency must be minimized even at
the expense of some loss in throughput. To evaluate this hypothesis we
introduce a new congestion control algorithm called TCP D*, which is a
congestion window first algorithm that adopts BBR's approach of
maximizing delivery rate while minimizing latency. In this paper, we
discuss the key features of this algorithm, discuss the differences
and similarity to BBR, and present some preliminary results based on a
real implementation."

"For a successful technology, reality must take precedence over public
relations, for Mother Nature cannot be fooled" - Richard Feynman

dave at taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729

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