[e2e] Policing TCP flows

[Greg Minshall]

Dennis,

(i'm using "shaping" to mean "by the router", rather than "pacing", by which i 
would mean "by the end host".)

here's a way to think of it:  shaping means delaying; delaying means 
increasing the RTT.

(here's another way to think of it:  shaping means slowing down the rate at 
which bits are injected into the pipe; slowing down means decreasing the 
bandwidth.)

it's been a while since i've looked at this.  i think my feeling at the time 
was that one needed to decide on a "reasonable" window size, and be prepared 
to hold on to that many packets in the shaping device.  2 packets doesn't seem 
reasonable, but i don't remember how many packets i buffered in my 
experiments.  it could have been as many as 64.

cheers, Greg