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From: Dave Taht <dave.taht@gmail.com>
Date: Thu, 13 Jun 2019 06:22:49 -0700
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Subject: [Cake] tunable delays for tcp
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this commit from the immortal edumazet arrived this morning in net-next:

https://www.spinics.net/lists/netdev/msg577452.html

...

> Adding delays to TCP flows is crucial for studying behavior
> of TCP stacks, including congestion control modules.
>
> Linux offers netem module, but it has unpractical constraints :
> - Need root access to change qdisc
> - Hard to setup on egress if combined with non trivial qdisc like FQ
> - Single delay for all flows.
>
> EDT (Earliest Departure Time) adoption in TCP stack allows us
> to enable a per socket delay at a very small cost.
>
> Networking tools can now establish thousands of flows, each of them
> with a different delay, simulating real world conditions.
>
> This requires FQ packet scheduler or a EDT-enabled NIC.


--=20

Dave T=C3=A4ht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-205-9740