Or perhaps more importantly, what if you have an existing piece of business logic you want to be a publisher, even if it is currently implemented with a point-to-point interaction pattern?

What if, in the point-to-point interaction pattern between the requester and publisher mediation, the requester already uses a publish/subscribe interaction pattern, as shown in Figure 2?

Because connection is the entry point to interaction with a JMS server, each implementation of a connection interface must know how to connect to an instance of its own JMS server.