[Cake] commit 0d8f30 breaks ingress mode

[Jonathan Morton]

> On 25 Dec, 2017, at 8:48 am, George Amanakis <gamanakis at gmail.com> wrote:
> 
> I modified rrul_be_nflows.conf to classify all generated traffic as
> CS1. Ran a simulation where one client downloads simultaneously from 4
> servers, 24 flows each. The latency is huge ~1000ms in this case. 

I've just pushed a fix for this one.  It's as simple as using the same mtu_time threshold for all tins.

This does mean that low-rate tins (such as Bulk) will be controlled to potentially unsustainably-low BDPs when competing against higher-rate tins.  However, that will only affect goodput in the low-rate tins (and when ECN is not being used by the endpoints involved).  I think that's an unavoidable tradeoff, and controlling latency is more important in this scenario.

 - Jonathan Morton