The NetworkServerSimple is a basic server class without the "game" related functionality that the NetworkServer class has.
This class has no Scene management, spawning, player objects, observers, or static interface like the NetworkServer class. It is simply a server that listens on a port, manages connections, and handles messages. There can be more than one instance of this class in a process.
Like the NetworkServer and NetworkClient classes, it allows the type of NetworkConnection class created for new connections to be specified with SetNetworkConnectionClass(), so custom types of network connections can be used with it.
This class can be used by overriding the virtual functions OnConnected, OnDisconnected and OnData; or by registering message handlers.