The Thinfinity® VNC Manager 'Communication' tab presents you with the following options:
Bind to IP
Use this option to restrict access to the service through one specific IP. The 'All unassigned' option allows access through all the possible IPs for the computer.
Choose between the http and https protocol. The https protocol uses SSL. Hence, it's more secure.
Choose the port number for this computer to be accessed.
If you support UPnP, check this option to make this computer available from outside your LAN in the port number chosen in the 'Port' field. If this port is already in use in the router, you might see this error message: 'UPnP Error: This port is assigned to another service/computer'
If this happens, choose a different port number in order to use UPnP.
Always remember to press 'Apply' in order to save the changes.