[Cake] dual-src/dsthost unfairness, only with bi-directional traffic

[Georgios Amanakis]

On Thu, 2019-01-03 at 23:06 +0100, Pete Heist wrote:
> Both have cake at 100mbit only on egress, with dual-srchost on client
> and dual-dsthost on server. With this setup (and probably previous
> ones, I just didn’t test it this way), bi-directional fairness with
> these flow counts works:
> 
> 	IP1 8-flow TCP up: 46.4
> 	IP2 1-flow TCP up: 47.3
> 	IP1 8-flow TCP down: 46.8
> 	IP2 1-flow TCP down: 46.7
> 
> but with the original flow counts reported it’s still similarly
> imbalanced as before:
> 
> 	IP1 8-flow TCP up: 82.9
> 	IP2 1-flow TCP up: 10.9
> 	IP1 1-flow TCP down: 10.8
> 	IP2 8-flow TCP down: 83.3

I just tested on archlinux, latest 4.20 on the router, iproute2 4.19.0,
using flent 1.2.2/netserver in a setup similar to Pete's:

client 1,2 <----> router <----> server

The results are the same with Pete's.