[Tmrg] Mix of RTTs

[Lachlan Andrew]

Greetings Sally,

I have a question about the connection between the traffic model and
RTTs to use in TCP analysis.

When the "better models" paper compares the simulated and measured RTT
distributions, it mentions that most packets come from the short-RTT
flows.  That will clearly be the case if all flows are long-lived, or
if the traffic model is "closed loop" in the sense that it consists
only of alternating "think times" and fixed-time files.

If the traffic consists instead of Poisson arrivals of "sessions",
each carrying a fixed amount of traffic (possibly in several
think/send bursts), then the amount of data sent at each RTT is
determined by the traffic model, independent of the actual RTTs.

At the round table, we agreed to have a traffic model of the second
kind.  Will that change the RTTs that we should use in the test suite?
 As I recall, you wanted to revise that section before the final
submission anyway.

Cheers,
Lachlan

-- 
Lachlan Andrew  Dept of Computer Science, Caltech
1200 E California Blvd, Mail Code 256-80, Pasadena CA 91125, USA
Ph: +1 (626) 395-8820    Fax: +1 (626) 568-3603
http://netlab.caltech.edu/~lachlan