Example Applications Certified delivery is appropriate when a sending program requires individual confirmation of delivery for each message it sends. For example, a traveling sales representative enters sales orders on a laptop computer, and sends them to a central office. The representative must know for certain that the order processing system has received the data. Certified delivery is also appropriate when a receiving program cannot afford to miss any messages. For example, in an application that processes orders to buy and sell inventory items, each order is important. If any orders are omitted, then inventory records are incorrect. Certified delivery is appropriate when each message on a specific subject builds upon information in the previous message with that subject. For example, a sending program updates a receiving database, contributing part of the data in a record, but leaving other parts of the data unchanged. The database is correct only if all updates arrive in the order they are sent. Certified delivery is appropriate in situations of intermittent physical connectivity—such as discontinuous network connections. For example, consider an application in which several mobile laptop computers must communicate with one another. Connectivity between mobile units is sporadic, requiring persistent storage of messages until the appropriate connections are reestablished.
