Beacon Server

The NLANR Multicast Beacon is active measurement software that monitors 
the performance of a multicast session. It has two components: 

Beacon Agent -- an active probing program running at each measurement machine. 
A set of Beacons sends packets continuously to each other through a 
multicast session, and measures the performance of the transmission. It 
then reports to the Beacon Server periodically. The current version (v0.63) 
is written in Java. 

Beacon Server -- a central server collecting the performance information 
from the Beacon Clients. The v0.8 version of the Beacon Server is written 
in Perl. 

WWW: http://dast.nlanr.net/Projects/Beacon/