So, I should write for ChatServer:
...
IPAddress ip(192,168,1, 77); // this is for the Arduino IP Address
IPAddress gateway(192,168,1, 1);
IPAddress subnet(255, 255, 0, 0);
...
then for the ChatClient:
...
IPAddress ip(192,168,1,77);
// Enter the IP address of the server you're connecting to:
IPAddress server(1,1,1,1);
Am I right?
if so, what should I do to chat?