C2MS12 — Create Service Registry/Lookup Messages

From an implementation standpoint, C2MS (and C2MS-EXT) Messages should be registerable at some kind of "C2MSMessageDescriptionManagerService" which serves them up, possibly pushing them out? To all active nodes on a gmsec bus ...

Perhaps a Register Service message that includes what 'services' and message types are provided, a Service Registered message published to all, a Lookup Service Request message that asks 'who can do what I need?' and a Service Lookup Response message.

C2MS doesn't need to define how that registry is maintained or made resilient or how services stay in the list (heartbeat?) at all. That is up to the implmentor, if any.