thrulay is used to measure the capacity of a network by sending a bulk
TCP stream over it.

Like other tools (such as iperf, netperf, nettest, nuttcp, ttcp, etc.),
thrulay can report TCP throughput periodically so that TCP performance
plots can be produced. Unlike other tools, thrulay not only reports goodput,
but round-trip delay time as well. The output of thrulay is easy to parse
by machine (in fact, it's ready to be used as a data file for gnuplot).

Starting from version 0.5, thrulay supports UDP tests. Unique feature of
thrulay is that it can send a Poisson stream of very precisely positioned
packets; the TSC register is used for timing rather than very coarse
(20ms on most systems) system sleep functionality.