The IndoorHub is just a “dumb” (non-routing) indoor access point with meshing. It simply creates an indoor WiFi signal with a slightly different SSID than the Hubs (it appends “-IndoorAP” to the end of the Hub’s SSID), on a different channel (to prevent interference with the Hubs) and a meshing signal specifically for other IndoorHubs. It was developed to keep people from using WiFi routers for indoor WiFi, because having more than one router in your network frequently leads to IP address conflicts. It is also designed to be extremely easy to set up and use.