private static Int32 port = 11000;
private static UdpClient udpClient = new UdpClient(port);

public static void receive_threaded()
{
    Thread t = new Thread(() =>
    {
        while (true)
        {
            IPEndPoint remoteIPEndPoint = new IPEndPoint(IPAddress.Any, port);
            byte[] content = udpClient.Receive(ref remoteIPEndPoint);

            if (content.Length > 0)
            {
                string message = Encoding.UTF8.GetString(content);
                if (action_message_receive != null) action_message_receive(String.Format("Recv({0}): {1}", remoteIPEndPoint.Port, message));
                parseMessage(message);
            }
        }
    });
    t.Start();
}

private static void send_message(string ip, string message)
{
    byte[] packetData = System.Text.UTF8Encoding.UTF8.GetBytes(message);

    int port = 11000;

    IPEndPoint ep = new IPEndPoint(IPAddress.Parse(ip), port);
    Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
    client.SendTo(packetData, ep);

    if (action_message_send != null) action_message_send("Send: " + message);
}