As we have discussed before, requiring RM at every node actually presents the possibility of a permanent block in a delivery chain should some IM not support. We cannot REQUIRE RM thus we cannot guarantee that the message will arrive, thus we MUST allow some other mechanism to notify the original sender of success (or failure -- failure can be defined as the lack of success since even if the message arrived, the loss of the DR is still a failure). Since RM cannot be required then we must allow the Sender to retry. I don't see the need for DR sent reliably. This is very similar to an Ack on an Ack. The only reason for sending reliably is if some action would be taken on failure. What would be the action? The only possible action I can think of is human intervention which would already be the case if the DR does not arrive. What have we gained by sending the DR reliably? Nothing, so let's not. As stated in a previous eMail, the CPPA parameters of Retries and RetryInterval are NOT hop-to-hop. They are end-to-end. These have always been intended to allow From Party MSH retries. Regards, David Fischer Drummond Group.
