[Tmrg] Traffic trace options

[Lachlan Andrew]

Greetings all,

A few people have asked for the traffic traces for the test suite.
How does this suggestion sound:

UNC have provided us with two traces.  Both are bidirectional, specify
the RTT of each flow, and are about one hour.  One is for sessions
started by a host inside their campus and one for sessions started
outside.

For simplicity, I propose using only the larger of these two.  I've
been told that Tmix can scale traffic loads, so that should do for all
load cases.

We need 9 separate traces for the 9 source/destination pairs, plus
another 9 in the reverse direction.  I propose subsampling the trace
to do that.  (That should maintain the correct correlation structure,
while overlaying 9 time-delayed copies of the same trace would reduce
burstiness.)  To do the subsampling, I propose sorting the sessions by
RTT, and allocating the top  11% to the S/D pair with the longest RTT
etc.

I also propose using a cyclic permutation of the trace, so that the
first 100s or so has the same load as the average over the entire
trace, to try to minimise the bias introduced by running very short
experiments.

Feedback on these proposals would be most welcome (or ask me to
explain it more clearly).  If no-one has any objections or
suggestions, Tom Q will post the 9 resulting traces on the web
sometime next week.

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