[e2e] [Fwd: RED-->ECN]

[Vishal Misra]

On Thu, 1 Feb 2001 julian_satran at il.ibm.com wrote:

> accepted queueing models.  Do you have in mind some "quantum statistics"
> for networks that we are all unaware of? Do those have some tunnel effects
> that allow you to dream about high utilization AND short queues? Is there
> some mathematics that can support your statements?

Yes, it is called "Control theory" and has been around for hundreds of
years. Steven is talking about a *closed loop* control system. TCP (which
is responsible for most of the queues in IP networks) is not an open loop
protocol. You cannot apply open loop queueing theory models to describe
the behavior of "elephants" which Steven was discussing. 

If your traffic is purely "elephant" then it is possible to design
controllers which simultaneously give low delay and (near) full
utilization. Several research groups have already done it and demonstrated
it both mathematically and through simulations/testbeds. The presence of
"mice" complicates things a bit since even though they might be carried 
by TCP they don't live long enough to be classified as "controllable".

-Vishal