Bandwidth estimation
Data collecting and processing programs
The following program sends a series of traceroutes
to a given destination. Each hop is probed with a
fixed number (of the order of 1000) of packets of
each size, and the sizes are scanned on a coarse grid
(e.g. through 100 bytes' increments).
After all hops have been probed with one packet size,
traceroute tries increments packet size and probes
the same destination through the same set of hops,
and with the same number of packets sent to each hop.
Yet another operating mode is to scan all possible
packet sizes on the finest scale possible,
sending a series of traceroutes with every
packet size between 40 and 1500 bytes. In that mode
we sent only one packet of each size to each hop.
bandetrt.pl
This version was used to measure Abilene route
to CAIDA's champagne monitor from gaos,
which is SDSC's SUN E10000;
see all files starting with "gao" in this file
and Abilene plots in the main exposition.
The program collects data in a file:
gaocha1.5k1126_2342.trt
It also produces table of the form: (packet size, RTT, hop):
chicha2k1122_0321.bwe
One of its output files is a table of minimum RTT as a function
of packet size for each hop:
chicha2k1122_0321.minsub
Next script converts traceroute log to RTT distributions.
The output table instead of RTT contains RTT - minRTT + 2*hop
in the first column. This is done in order to show all hops
on one plot.
splitbyhop.pl
Output example:
chicha2k1122_0321.bwehopdtr
varPackRttDensNoPrep.pl
Next files are outputs of this program.
chicha2k1122_0321.rttdens.hop1
chicha1.5k1125_0425.rttdens.allsize
Next program is used to compute the difference between median and minimum
for the aggregate of shifted distributions with varying packet sizes for
size-dependent delays. It was also used to try other measures of spread,
e.g. entropy or interquartile distance. (These quantities are still computed,
but their output is disabled since median-minimum works much better.)
bwShiftScan.c
Data files to check if and how shift scan works
chicha2k1122_0321.bwehopdtr.stk1nsbit
chicha2k1122_0321.bwehopdtr.stk0.5nsbyte
chicha2k1122_0321.bwehopdtr.stk0.25nsbit
chicha2k1122_0321.bwehopdtr.stk.log
Entropies
chicha2k1122_0321.bwehopdtr.ent
minslope.pl