OWAMP is a command line client application and a policy daemon used
to determine one way latencies between hosts. It is an implementation
of the OWAMP protocol as defined by
http://www.rfc-editor.org/rfc/rfc4656.txt. (When referring to the
protocol within this document, "OWAMP" will be in italicized. In
all other instances, "OWAMP" will be referring to this implementation.)

With roundtrip-based measurements, it is hard to isolate the direction
in which congestion is experienced. One-way measurements solve this
problem and make the direction of congestion immediately apparent.
Since traffic can be asymmetric at many sites that are primarily
producers or consumers of data, this allows for more informative
measurements. One-way measurements allow the user to better isolate
the effects of specific parts of a network on the treatment of
traffic.