[Cake] Upstream submission of dual-mode fairness patch

[Jonathan Morton]

> On 3 Mar, 2019, at 6:07 pm, Pete Heist <pete at heistp.net> wrote:
> 
> Does it say anything to you that enabling ECN makes the asymmetry go away?

Yes - it tells me that it has something directly to do with how dropped packets are accounted for, not with the congestion response by TCP.  ECN changes the number of dropped packets, and shouldn't change the congestion response.

 - Jonathan Morton