>Have the WiFi Access Point, or some other gateway, act as the broker for all information, and the default is each device sees nothing until given permission. *

>Have the WiFi Access Point, or some other gateway, act as the broker for all information, and the default is each device sees nothing until given permission. * Not everywhere is going to have WiFi. A SIM can use a private APN that selects the PGW/IP/Network range and from the ISP usually has a VPN to your network. Does not go "over the internet" at all. This is (usually) how industrial IoT, connected cars etc work. Shipping containers cant rely on WiFi.