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

[Fred Baker]

At 08:40 AM 2/1/01 -0500, Michael B Greenwald wrote:
>If the input rate is less than the
>output rate, then (independent of variations in inter-arrival time) the
>queue length is 0 -- always empty.  For an arbitrarily low *average* input
>rate, and a long enough interval, and an unbounded queue, I can construct
>an arrival schedule that will cause an arbitrarily high *average* queue
>length.

who told you that?

I think you'll find that with any distribution, mean queue depth is not a 
binary flip-flop between zero and infinity. With poisson distributions 
(M/M/1) and a ratio if input rate to output rate of p and mean service 
interval m, Kleinrock tells me that the average time in queue (which is to 
say mean queue depth including the packet itself)

              p/m
         W = -----
             1 - p

and in the general case

              average remaining service time
         W = --------------------------------
                         1 - p

That's far from a step function.