Why can't my application receive the data using UDP in Hotsport network?
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Why can't my application receive the data using UDP in Hotsport network? But my application can receive the data using UDP in normal Wi-Fi network.
The code of the sender is:

    @Override
    	public void run() {
    		super.run();
    		DatagramPacket dataPacket = null;
    
    		try {
    			udpSocket = new DatagramSocket(DEFAULT_PORT);
    
    			dataPacket = new DatagramPacket(buffer, MAX_DATA_PACKET_LENGTH);
    			while (isRunning) {
    				String address = getLocalIPAddress();
    				if (address != null) {
    					byte[] data = address.getBytes();
    					dataPacket.setData(data);
    					dataPacket.setLength(data.length);
    					dataPacket.setPort(DEFAULT_PORT);
    					InetAddress broadcastAddr;
    					broadcastAddr = InetAddress.getByName("255.255.255.255");
    					dataPacket.setAddress(broadcastAddr);
    					try {
    						Log.i(DazzleApplication.TAG,"Sending---->"+address);
    						sleep(3000);
    					} catch (Exception e) {
    						e.printStackTrace();
    					}
    				}
    			}
    			if (udpSocket != null)
    				udpSocket.close();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    
    	}

The code of the receiver is:

    public void run() {
    			DatagramPacket udpPacket=null;
    			byte[] data=null ;
    			try {
    				udpSocket = new DatagramSocket(43708);
    				udpSocket.setSoTimeout(3000);
    				data= new byte[256];
    				udpPacket= new DatagramPacket(data, 256);
    			} catch (SocketException e) {
    				e.printStackTrace();
    				System.out.println(e.toString());
    			}
    			while (start) {
    				System.out.println("DazzleTest Receive.....");
    				try {
    
    					udpSocket.receive(udpPacket);
    				} catch (Exception e) {
    					e.printStackTrace();
    					System.out.println(e.toString());
    				}
    
    				if (udpPacket.getLength() != 0) {
    					String codeString = new String(data, 0,
    							udpPacket.getLength());
    					Message msg = new Message();
    					msg.obj = codeString;
    					mH.sendMessageDelayed(msg, 1000);
    					System.out.println("receiver--->"+codeString);
    				}else{
    					System.out.println("receiver null");
    				}
    			}
    			if (udpSocket != null) {
    				udpSocket.close();
    			}
    
    		}


Why? Who can explain this case? The UDP can't work in Hotspot??