C2MS12 — Make SERVICE-NAME an Alternate way to Reach a Service

For Request Messages, ME1 is always the DESTINATION-NODE, currently.

Add another ME value for SERVICE-NAME. Make it mutually-exclusive. You either specify DESTINATION-COMPONENT or SERVICE-NAME. If the former, it's like it is today. If the latter, it is a REQUEST that doesn't know which component will process it.

We have to make ME1 optional for these request messages..

Strengthen the discussion of "FILL" in 6.2.2. State that is is a reserved word in subjects and that not only can it be sent as FILL, but a subscriber can also subscribe to FILL to catch cases where the DESTINATION-COMPONENT is not specified.

Add a subsection that talks about requests and their use of SERVICE-NAME. These services should subscribe to FILL for D/C so that they respond to any request with the SERVICE-NAME.

Somewhere Describe sense of component registry and not allowing more than one component to subscribe. These would be implemented in the domain according to domain requirements. In other words, Explain the peril about multiple responders and guidelines of how to approach it. Maybe they create a registry/lookup. Could use C2MS-EXT messages. Maybe we adopt this at a future time.