Netperf is a serious networking performance evaluation tool being
distributed under GPL by HP's Information Networks Division.
Testing is done using a pair of programs: `netserver' (the server) and
`netperf' (the measurement tool).

Netperf allows control over a large number of test `variables'.
Some of these are:
        * specification of desired confidence levels for the tests
          Netperf will warn the user if these levels were not achieved.
        * filling send buffers with specified data (to beat compression schemes)
        * specification of send/receive buffer alignments and data offsets
        * requesting CPU utilization and service demand calculations
        * specification of sizes of data to send
Netperf can be used for measuring stream performance as well as
round-trip performance.

WWW: http://www.netperf.org/