I have a SNTP client Pro.£¬It needs send 48byte data packet to SNTP server¡£But "Timeout" appear when I runnig it£¬is the udp data type wrong£¿


    DatagramSocket so = new DatagramSocket(13);
    so.setSoTimeout(8000);
    int clientms[] = new int[48];
    clientms[0]=0x23; //the first 8 bit'00100011' means it's a client
,VISION 4;
    byte[] data = new byte[48]; //sntp message has 48 byte;

    for (int i=0;i<48;i++) {
       data[i] = (byte) clientms[i]; //int array convert to byte array
       System.out.print(data[i]+" ");
      }
    DatagramPacket packet = new DatagramPacket(data,data.length,
    InetAddress.getByName(machine),daytimeport);

    so.send(packet);

    packet.setData(new byte[48]);
    so.receive(packet); //If server response£¬the it return 48byte data

    String inMessage=new String(packet.getData(),0,data.length);
    System.out.println("received message: "+ inMessage);
    so.close();