Hi Prad,
You need to distinguish between ACKs:
- Technical acknowledgment: MDN is not a EDI message by himself, just an option in your AS2 receiver channel.
- Functional acknowledgment: 997 or CONTROL has EDI message entity, I mean should be treat as DESADV or ORDERS, and for that reason you should require MDN of these messages.
so MDN to confirn technical ACK and 997 like functional ACK with his MDN to confirm reception.
You should agree with your client what kind of ACK they are able to handle and configure your B2B addon according it.
cheers,
Roberto.