RNP > Technologies > Multicast > Beacon Server

Beacon Server and Beacon Client

The Beacon package consists of two programs: the Beacon itself (also called Beacon Client) and the Beacon Server.

Beacon is a little Java program. When triggered, Beacon starts sending and receiving data of a specific multicast group, to which other Beacons will also be connected. All the Beacons begin exchanging information among one another and calculating parameters such as loss, delay and jitter.

These data are sent to a central station, the Beacon Server, where they are consolidated. The resulting parameter matrix is presented in HTML format, permitting the users to evaluate how the connectivity of the Beacon itself is with the others.

Therefore, the procedure of use can be summarized as follows:

1 – Triggering the Beacon, configuring it to transmit/receive in a certain multicast "G" group

2 – Accessing the Beacon Server (responsible for the "G" group) in order to check the connectivity of the Beacon itself with the others.

In RNP, the G=233.7.124.1 group will be specifically allocated for this function. RNP's Beacon Server can be accessed in the address http://beaconserver.nc-rj.rnp.br.

RNP will always keep a Beacon running in its unit in Rio de Janeiro (NC-RJ), in order to interact with other Beacons.

More details about the Beacon tool can be obtained in the addresses:
http://dast.nlanr.net/Projects/Beacon/
http://dast.nlanr.net/Projects/Beacon/guide_beacon.html

Download

The package of Beacon programs can be obtained in the URL:
http://dast.nlanr.net/Projects/Beacon/#download.

For the final users, only Beacon Client is necessary. It is important to point out that Beacon Client is a program written in Java. Therefore, having the JDK installed is a fundamental pre-requisite to use it.

Configuration

The Beacon Client package contains a triggering script. For UNIX-like systems, this script is called start_beacon.sh, while for Windows stations it is called start_beacon.bat.

In order to use RNP's Beacon Server, the script must be configured with the following parameter:

multicast_group=233.7.124.1
multicast_port=10100
beacon_server=beaconserver.nc-rj.rnp.br
server_port=9997

Note: the delay measurements among Beacons will only be valid if the clocks of the client stations are synchronized. Thus, we suggest that these machines use NTP. More details can be obtained in the Beacon documentation (see Beacon User's Guide).