Hi ekimm2,
In the future it will be handled by NoMachine Anywhere.
Right now routers supporting UPnP or NAT-PMP are configured automatically to pass connections to NoMachine and all required informations are displayed at initial screen (Welcome to NoMachine).
Routers not supporting UPnP or NAT-PMP and Firewalls have to be configured manually to pass traffic to port 4000 (NX protocol), 22 (SSH protocol on Linux/MacOSX) or (4022) (SSH protocol on Windows).