Distributed trust center

On a distributed trust center (EO = 0), registration is persistent, meaning that the registered device will always be authorized to join as long as the join window is open. Registration information is not shared to the rest of the network, so the 0x24 registration frame must be issued to a router that is adjacent to the joining device. Because the link key table has a limited number of entries, you must explicitly remove key table entries by deregistering devices using a 0x24 frame after they successfully join to add subsequent devices. The key table on a distributed trust center is stored in flash and persists across a power cycle.

Once a device joins the network and obtains a copy of the network key, it retains information about the network and performs a secure rejoin, if power cycled. If you change a network parameter on the device, it receives a leave request or a secure rejoin fails after three tries. The device must join the network via association which requires registration.