naisdevice is currently in open beta. When released it will replace NAVTunnel/ScaleFT.
Until further notice naisdevice is only offered to machines that are purchased and managed by NAV. You might get som mileage off a non-NAV device, but please refrain from attempting to do so. There is a fair amount of legalese that needs interpretation before we can offer naisdevice "in the wild".
If you want to understand more about how it works, head over to the github repository and check out the project documentation.