Juraj:
not a GET request, please. nice plain telnet is good. start a server at port 2323 and connect to it from client and send what you want and process it on server and eventually send something back to client.you can test the server with telnet client (telnet 2323)
Why tie up a connection, when the only information that needs to be exchanged involves the door being opened or being closed? How often is THAT going to happen?