[Bloat] About LEDBAT, µTP and BitTorrent

[Luca Dionisi]

On Fri, Feb 4, 2011 at 11:04 AM, Juliusz Chroboczek <jch at pps.jussieu.fr> wrote:
>> I think that the 2 things have to be carried on independently,
>
> Yes.
>
>> The problem is that one cannot make sure that end users will act
>> fairly, by adjusting their sending rate.  The only way to do this is
>> dropping packets, so that they are obliged to send again.
>
> Well, the issues of increased delay and greedy, unresponsive flows are,
> to a certain extent, distinct.  One can image AQMs that are only
> concerned with penalising unresponsive flows but don't do anything to
> reduce buffer size when all flows are well-behaved.  Conversely, one can
> imagine solving the buffer bloat problem on the assumption that all
> flows are TCP-friendly.

I don't get it. Why do we need to make such an assumption?
If the routers keep a low buffer size (better if dynamically, if I am
correct) and much better if they *also* implement a AQM which
rate-limit the unresponsive flows, then we will have almost solved the
problem and *also* actually discouraged unfair behavior from clients.