IRTT (Isochronous Round-Trip Tester) is software that runs on a client
and server, using its own UDP-based protocol to allow measurements
including round-trip time, one-way delay (assuming the clocks are
synchronized), and lost/out-of-order/duplicate packets.
It has features for reasonably secure use on both public and private
servers, including optional HMAC (access control) and three-way
handshake (anti-spoofing).
