The program thrulay is used to measure the capacity, delay, and
other performance metrics of a network by sending a bulk TCP or UDP
stream over it.

Special features of thrulay include:
* For TCP, ability to measure round-trip delay along with throughput
* For UDP, ability to measure
  - one-way delay, with quantiles
  - packet loss
  - packet duplication
  - reordering
* For UDP, the ability to send precisely positioned true Poisson streams
  (microsecond errors in sending times)
* Human- and machine-readable output (ready to be fed to gnuplot)

WWW: http://www.internet2.edu/~shalunov/thrulay/