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

[Alhussein Abouzeid]

Hi Steven,

Thanks for the clarifications and replies. I'd like to bring in a relevant
issue to discuss in connection to your proposed algorithm. 

In reference to the exponential packet marking used in REM, and apart from
the nicities of it being continuous, and that REM offers much more than
just proposing an exponential distribution dropping, my gut feeling is
that the exponential distribution is actually the best choice, not
because of its mathematical tractability (due to its memorylessness) but
out of an engineering/mathematical points of view. 

The only work I know of that attempted to derive this marking function
mathematically, though in an ATM environment, is "A random early
discard framework for congestion control in ATM networks",
AU: Mokhtar-A; Azizoglu-M, SO: IEEE ATM Workshop '99 Proceedings. Do you
have any motivations behind choosing the shape of the marking/dropping
function to be exponential, other than mathematical convenience.

Indeed, relying on a fixed drop probability profile alone, without making
it adaptive in some sense (using optimization-theoretic algorithms like
REM or control-theoretic algorithms as Vishal's  recent work
or any other adaptive fashion) will most definitely result in an abysmal
performance. However, in connection with your specific algorithm (REM), 
the shape of the marking function choice seems (to me, but you should know
better) important.

So my question in other words is: How would a different choice of the
random drop/marking function affect the convergence properties of your
algorithm.

Regards,

Alhussein.