TNet gives you an option to have a lobby server where physical servers register themselves, but it's not a necessity. The actual game servers do not communicate with each other by default. You can make them communicate, but it would all be custom logic here, so it's up to you to add. Cloud servers (which is what you are talking about) is a vastly complicated topic, and is outside TNet's scope. Actual TNet servers are limited by the hardware for the number of CCUs.