C2MS — Acknowledge Final Status inconsistency

Based on review of latest specification, the problem detailed in C2MS-5 is still present. This problem makes it not possible for a client application to properly be developed to support all MEPs. If a client application is developed to support MEP2, then it will ignore all future responses after the first ACK comes in when communicating with a server that supports MEP4 or MEP5. If a client application is developed to support MEP4 and MEP5, then it will never think that a request finished when communicating with a server that supports MEP2.

As is currently specified, via table 6-9 on page 20, the Acknowledge is listed as a Final Status. Though it is only a final status in MEP2.

Possible solutions:
1. Remove MEP2. This would make Acknowledge in Table 6-9 have a Final Status of "No"
2. Add an additional status code of Acknowledge Complete (perhaps #7). In this option, Acknowledge (#1) would have Final Status of "No", though new Acknowledge Complete (#7) would have Initial Status of "Yes", Intermediate Status of "No", and Final Status of "Yes".

Defer to next revision

This issue has ripple effects to more of the document. Needs more thought.