Always unencrypted message header to be able to find decryption key by device id.

Request to join IoT network from device.

Request to join response from controller to device.

Diffie-Hellman key exchange: device to controller.

Diffie-Hellman key exchange: controller to device.

Deveice request to leave IoT network.

Controller response to leave network request.

A message followed by Header and describes common parameters for all device / controller messages.