[Cake] [lede-project/source] Add support for cake qdisc (#72)

[David Lang]

On Wed, 1 Jun 2016, moeller0 wrote:

> Hi Jonathan,
>
>> On Jun 1, 2016, at 15:51 , Jonathan Morton <chromatix99 at gmail.com> wrote:
>> 
>> 
>>> On 1 Jun, 2016, at 15:25, Benjamin Cronce <bcronce at gmail.com> wrote:
>>> 
>>> 1) Ideally, regardless of platform, should an AQM or scheduler have the 
>>> responsibility of changing anything other than ECN?
>> 
>> This was in part my original objection to having the squash/wash feature in 
>> Cake.
>> 
>> The other part is that if we are going to rewrite the rest of the TOS byte 
>> (not just the ECN bits), then we should do it properly, which requires a 
>> rather substantial extension to the configuration API, even if we only try to 
>> cover the most obvious use-cases.
>
> 	To play devils advocate here, re-mapping to zero might be a special 
> case, but probably the single most important special case, so lack of 
> generality is not the strongest argument against it (as long as the goal is 
> “good enough”). But I already conceded, it is contentious so needs to go, cake 
> is your “baby” so you have the honor to make such calls…

The remap to 0 is arguably not just the most important special case, but the 
sensible default at any perimeter.

Having to setup iptables rules to do so is going to be significantly slower then 
doing it in Cake.

I think this one special case should probably remain.

David Lang