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A comment on Google NetStack: IPv4 and IPv6 userland network stack in Go. Parent comment

Re:Google NetStack: IPv4 and IPv6 userland network stack in Go by beagle3 on Thursday October 26, 2017 @09:00AM (#15558383)
The way ledbat works is by measuring the derivative of round trip time with respect to a throttled receive bandwidth. As long as RTT is constant or decreasing, keep increasing bandwidth; if RTT is increasing decrease bandwidth.

The server has to give you an indication of round trip for that to work - although I suspect there’s some clever way to get it using Some kind of URG or OOB or keep alive even if the server doesn’t natively support TCP ledbat.

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Re:Google NetStack: IPv4 and IPv6 userland network stack in Go by toast0 on Thursday October 26, 2017 @10:55AM (#15559356)
If you've negotiated tcp timestamps, and you assume the server will send more data immediately when it gets an ack, you have a convenient round trip time signal in the echoed timestamps. If you don't have tcp timestamps, you can advertise a reduced window and time the round trip between acks that open up the window and packets with sequence numbers in the window.
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