Is there a common standard/practice for having an IOT device establish a connection to a command and control server, and then act in a server role (i.e. the C&C sends requests to the device and the device sends back responses)? Something in the vein of reverse HTTP or RPC.
EDIT: an example use case: The device is behind a NAT gateway and the C&C is unable to initiate a connection to it. We want to send a "ping" message the device (to see if it's on and healthy or something) and receive a "pong" in reply.