Beacon Deployment

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

• Beacon Client
  An active probing program running at each 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.
  
  
• Beacon Server
  A central server collecting the performance information from the Beacon Clients.

Multicast Beacon is a simple and flexible tool and does not require any special support from routers. It relies on a number of agents spread over the network that communicate with a central server-manager. The agent-beacons (or beacon clients) simultaneously send and receive multicast packets carrying a packet sequence number and a timestamp. The beacons are statically configured with the multicast group address and port that these packets are sent to and with a few other parameters. The beacon clients receive the packets from all others. From the packet sequence numbers they can determine packet loss, duplication and reordering. Naturally, in order to get sensible results for one-way delay measurements, the beacons have to be synchronised, through NTP.

All active beacon clients send their raw statistics periodically to the Beacon Server via unicast UDP.

The following parameters can be measured by Beacon:

• Loss
• Delay
• Jitter
• Order
• Duplicate.

The Beacon may present its statistics using a Java viewer module or web browser (via HTTP). The second method allows the publication of information to all Internet users.

GÉANT2-Specific Beacon Guidelines

The NLANR beacon will be installed on each PoP WS2.

To be able to measure the delay. NTP must run on the workstation also.

Two Beaconserver matrix will be built for different purposes and different metrics:

• Internal matrix BeaconServer
• External matrix BeaconServer.

Internal Matrix BeaconServer

The address used for Beacon: 233.81.229.1

This address has to be filtered out at the edge of the GÉANT2 backbone, to not disturb the monitoring process by illegal senders (either from NRENs side).

The Beacon server is installed in the network in the Paris PoP. The Web interface is available for NRENs to monitor the multicast behaviour of GÉANT2.

The Beacon server is based on the Beacon Server with History feature.

The internal Beacon server is available to NRENs in the stats portal.

External Matrix BeaconServer

The address used for Testing Beacon: 233.81.229.200

This testing BeaconServer is open for the NRENs to join and test their multicast connectivity. We can explicitly ask the NOCs of NRENs to set up a Beacon agent and join this group to help to debug multicast in the network.

The testing Beacon server is installed in the network, at the Paris PoP. The Web interface is available for NRENs to debug the multicast setup of GÉANT2.

The testing Beacon server is based on the Beacon Server with History feature.

The external Beacon server is available: stats.geant.net

The parameters to setup your beacon agent:

multicast_group=233.81.229.200 
multicast_port=56465 
beacon_server=beaconserver.geant.net 
server_port=19997 
time_to_live=127 
user_name=beacon