Re: [Bloat] [Cerowrt-devel] DOCSIS 3+ recommendation?

[Jonathan Morton <chromatix99@gmail.com>]

> On 21 Mar, 2015, at 02:38, David Lang <david@lang.hm> wrote:
> 
> On Sat, 21 Mar 2015, Jonathan Morton wrote:
> 
>>> On 21 Mar, 2015, at 02:25, David Lang <david@lang.hm> wrote:
>>> 
>>> As I said, there are two possibilities
>>> 
>>> 1. if you mark packets sooner than you would drop them, advantage non-ECN
>>> 
>>> 2. if you mark packets and don't drop them until higher levels, advantage ECN, and big advantage to fake ECN
>> 
>> 3: if you have flow isolation with drop-from-longest-queue-on-overflow, faking ECN doesn’t matter to other traffic - it just turns the faker’s allocation of queue into a dumb, non-AQM one.  No problem.
> 
> so if every flow is isolated so that what it generates has no effect on any other traffic, what value does ECN provide?

A *genuine* ECN flow benefits from reduced packet loss and smoother progress, because the AQM can signal congestion to it without dropping.

> and how do you decide what the fair allocation of bandwidth is between all the threads?

Using DRR.  This is what fq_codel does already, as it happens.  As does cake.

In other words, the last half-dozen posts have been an argument about a solved problem.

 - Jonathan Morton