Discovery mechanism for Controller consists of the follow steps:
1. Send a multicast UDP request with string "openremote" to 220.127.116.11:3333.
2. Start up a TCP server with port 2346 to wait for the server URL feedback from Controller.
- Success: On Controller side, when receives the data, Controller will set up a TCP connection according to the host IP in the UDP with 2346 port,and then sends its URL back ,e.g:"http://10.10.10.101:8080/controller", through this TCP connection.
- Fail: fails to discover Controller URL if nothing is received within 5 seconds.