title: Data Sent over UDP socket didn't Recieved
body: <p>I am new to WebRTC Android, by using jStun with code below, I am able to get Public IP and Port of my android Devices.</p>
  
  <pre><code>    new Thread() {
          @Override
          public void run() {
              super.run();
              try {
                  MessageHeader sendMH = new MessageHeader(MessageHeader.MessageHeaderType.BindingRequest);
                  ChangeRequest changeRequest = new ChangeRequest();
                  sendMH.addMessageAttribute(changeRequest);
                  byte[] data = sendMH.getBytes();
                  s = new DatagramSocket(4500);
                  s.setReuseAddress(true);
  
                  DatagramPacket p = new DatagramPacket(data, data.length, InetAddress.getByName("stun.l.google.com"), 19302);
                  s.send(p);
  
                  DatagramPacket rp;
                  rp = new DatagramPacket(new byte[32], 32);
                  //Recieve Packet from Stun Server
                  s.receive(rp);
  
                  MessageHeader receiveMH = new MessageHeader(MessageHeader.MessageHeaderType.BindingResponse);
                  receiveMH.parseAttributes(rp.getData());
                  final MappedAddress ma = (MappedAddress) receiveMH
                          .getMessageAttribute(MessageAttribute.MessageAttributeType.MappedAddress);
  
                  //Show Public IP and Port On Text View
                  runOnUiThread(new Runnable() {
                      @Override
                      public void run() {
                          TextView myIp = findViewById(R.id.listeningIp);
                          TextView myPort = findViewById(R.id.listeningPort);
                          myIp.setText(ma.getAddress().toString());
                          myPort.setText(ma.getPort() + "");
                      }
                  });
  
  
                  while (true) {
                      byte[] b = new byte[1024];
                      DatagramPacket rr = new DatagramPacket(b, 0, b.length);
                      //This Recieve Aimed to Recieve from Laptop Packet Sender
                      s.receive(rr);
                      final String sss = new String(rr.getData());
                      Log.e("recieved", sss);
  
                  }
  
              } catch (Exception e) {
                  e.printStackTrace();
              }
  
          }
      }.start();
  </code></pre>
  
  <p>Public IP and Port of Android Device: 39.41.148.77:4500</p>
  
  <p>But when I send A Packet From Laptop Packet Sender Software to Android(39.41.148.77:4400) It didn't get Received. </p>
  
  <p>Any Guide is appreciated. Thanks</p>
  
  <p><a href="https://i.stack.imgur.com/LM1Fu.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LM1Fu.jpg" alt="enter image description here"></a></p>