public void startServerBroadcast() {
        // send broadcast and start as response listener
        if(running) 
            return;
        
        running = true;
        byte[] buffer = initCode.getBytes();
        try {
            start();
            InetAddress broadcastAddress = InetAddress.getByName("255.255.255.255");
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length, broadcastAddress, udpServerPortNb);
            socket.send(packet);
        } catch(Exception e) {
            System.out.println(e.getMessage());
        }
        responseListenTimer = new Timer(responseWaitTime, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                stopServer();
                
            }
        });
        responseListenTimer.setRepeats(false);
        responseListenTimer.start();
    }