Orchestrations subscribe and publish messages to the
MessageBox. They can do this in a number of different ways dependent on what messaging pattern the developer wants to use. Orchestrations can be bound directly to the
MessageBox, bound to Receive and Send Ports or configured to route messages between Orchestration instances. The only time the
MessageBox is not involved is when you use the Call Orchestration shape to initiate execution of another Orchestration, as explained earlier in this chapter. For the next few sections we are going to examine Orchestration Ports and Subscription patterns.
Ports in Orchestrations describe how the Orchestration will communicate with the