Re: Multi-hop reliable messaging

[Nikola Stojanovic <nhomest1@twcny.rr.com>]

<Nikola 1>
<Comment 5: page 18>
"Requires Message 4 to contain "Ref to" to Message 2". ##Yes## I would
establish
this as "ImplicitAcknowledgment" Pattern for all Implicit Acks and move it
earlier in the doc.
</Comment 5: page 18>
</Nikola 1>

<David 1>
##No, it's not an implicit ack since there is an explicit ack in Message 3.
However there is an interesting UseCase where Message 3 fails permanently,
but Message 4 arrives. In which case, although an explicit ack was
intendeded, actually there was an implicit ack instead.##
</David 1>

From the doc: "Intermediate MSHs needs to know that Message 4 from Party Two
is implicit ack to Message 1 from Party One. Requires Message 4 to contain
"Ref to" to Message 2". How would the Hub know that it is implicit to
Message 1 and explicit to Message 2 when it has the same "RefToMessageId"?
And your definition of an Acknowledgement: 'An acknowledgement to a message
that was previously sent is identified by the receipt of a message that
includes a "RefToMessageId" that contains the MessageId of the message that
was previously sent.' And, as you confirm, if Message 3 fails, and Message 4
arrives, Message 4 serves the purpose of an implicit Ack? I need to digest
rule: "Implicit and explicit acks must not be mixed on a single conversation
over one hop" a little bit more, but it seems like this morphing between
implicit and explicit may break it?

Regards,
Nikola