[wiki:WikiStart Orbit] > Tutorial-1: Hello World Example The "Hello World" Experiment is simple. The script for this experiment is shown below. {{{ Experiment.name = "tutorial-1a" Experiment.project = "orbit:tutorial" # # Define nodes used in experiment # defNodes('sender', [1,1]) {|node| node.image = nil # assume the right image to be on disk node.prototype("test:proto:sender", { 'destinationHost' => '192.168.1.2', 'packetSize' => 1024, 'rate' => 300, 'protocol' => 'udp' }) node.net.w0.mode = "managed" } defNodes('receiver', [1,2]) {|node| node.image = nil # assume the right image to be on disk node.prototype("test:proto:receiver" , { 'protocol' => 'udp' }) node.net.w0.mode = "master" } allNodes.net.w0 { |w| w.type = 'b' w.essid = "helloworld" w.ip = "%192.168.%x.%y" } # # Now, start the application # whenAllInstalled() {|node| wait 30 allNodes.startApplications wait 40 Experiment.done } }}} Figure 1. Script for "Hello World" Experiment To understand the details of the script, go [wiki:Tutorial/UnderstandingHelloWorld Understanding the Hello World Script]