[Bloat] when does the CoDel part of fq_codel help in the real world?

[Mikael Abrahamsson]

On Thu, 29 Nov 2018, Stephen Hemminger wrote:

> The problem is that any protocol is mostly blind to the underlying 
> network (and that can change).  To use dave's analogy it is like being 
> put in the driver seat of a vehicle blind folded.  When you step on the 
> gas you don't know if it is a dragster, jet fighter, or a soviet 
> tractor. The only way a protocol can tell is based on the perceived 
> inertia and when it runs into things...

Actually, I've made the argument to IETF TCPM that this is not true. You 
can be able to communicate earlier data from previous flows on the same 
connection so that new flows can re-learn this.

If no flow the past hour has been able to run faster than 1 megabit/s and 
always PMTUD to 1460 bytes MTU outbound, then there is good chance that 
the next flow will encounter the same thing. Why not use this information 
when guessing how things will behave going forward?

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se