sends all devices with port(10000) in LAN

room.js

var dgram = require('dgram');
var assert = require('assert');

var args = process.argv.slice(2);
var port = parseInt(args[0]);
assert.ok(typeof port === 'number');

var dc = dgram.createSocket('udp4');
dc.on('error', function(err) {
  throw err;
});
dc.on('message', function(msg, rinfo) {
  console.log(arguments);
});
dc.on('listening', function() {
  var addr = dc.address();
  console.log('datacenter listening on: ' + addr.addr + ':' + addr.port);
  after();
});

dc.bind(port);

function after() {
  // ready for broadcast                                                                                         
  var msg = new Buffer('beep');
  dc.setBroadcast(true);
  dc.send(msg, 0, msg.length, 10000, '255.255.255.255', function(err, bytes) {
    console.log(arguments);
  });
}