For internet access, sensors and controls have to either be directly connected to an internet node (e.g. by Wifi) or a gateway gathers local data and makes them available for the internet. The gateway is inside a local network and cannot easily be reached from outside. As long as IPv4 addresses dominate the market, households have no static IP address but are serviced through by system of changing IP addresses. With that it is difficult to address hardware inside the network from outside. There are DDNS servers available which offer a dynamic name association with servers inside the local network. The set-up of such services will typically not be executed by consumers.

With IPv6 addresses this will change, since every device in internet can get its individual address and with that can be reached from everywhere. Although it is technically feasible today it will still take 5 to 10 years, before IPv6 becomes the standard addressing scheme.

Before that is solved, connections to devices inside a local network have to be made by cloud server, where both, the device and the human or other machine interfaces have to register first, before they are connected by the server.