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.