Then what prevents the app from being the path, in either/both directions? Reporting on the activities of the devices it can see, as well as sending firmware updates to them?
Your printer gets firmware updates from HP, whenever HP wants, right past all your firewalls and vlans and non-routable subnets, in the form of print jobs from your pc.
Your printer gets firmware updates from HP, whenever HP wants, right past all your firewalls and vlans and non-routable subnets, in the form of print jobs from your pc.