[ee122] MNL not simulating congestion correctly

[Eric Cheung]

We are doubling the RTO after every timeout and reducing the CWND. 
However, we've run into a problem where MNL (with drop probability .25) 
keeps dropping packets regardless of how slow we are sending, causing 
our RTO to keep doubling.  This seems to be counter-intuitive to the 
behavior of an actual congested network, which would drop less packets 
if a sender reduced its sending speed.  Is this a fundamental problem 
with the way MNL models the network or do we have to account for this 
somehow?

Thanks
- Eric