private static byte[] EncryptionKey = { 0xA7, 0x84, 0x20, 0xD0, 0xC9, 0x78, 0xB3, 0x9A };
    private static string filter = "port 12000 and len > 60";
    private static int readTimeoutMilliseconds = 1000;
    private static int defaultDevice = -1;
    private static System.Collections.Generic.List<byte> _incomingBuffer = new System.Collections.Generic.List<byte>();

device.OnPacketArrival += new PacketArrivalEventHandler(PacketCapturer);

device.Open(DeviceMode.Promiscuous, readTimeoutMilliseconds);
 device.Filter = filter;
 device.StartCapture();