I'd use it.
Should we keep the convention of 5000's for request and 6000's for responses?
E.g. 5999 ping, 6999 pong, 7000 some other message
Discussion
I was just thinking of this as a special kind, not an actual job request.
Each DVM should respond to its job request (5000 range) with a job response (6000 range) AND it should respond to a ping with a status.