tcpbench(1) on OpenBSD
The text 7271002c9d4f, as OpenBSD 5.6, OpenBSD 5.5 shipped it.
TCP/UDP benchmarking and measurement tool
Flags it lists
-
-B -
-S -
-T -
-V -
-b -
-k -
-l -
-n -
-p -
-r -
-s -
-t -
-u -
-v