According to the Oracle methodology formalized in the AIA approach, Enterprise Service Bus is the only mandatory pattern in the enterprise SOA infrastructure, which is maintained as an EBS framework. That's what we have learned in the first two chapters. At the same time, in our practical exercise in the previous chapter, we started with Enterprise Business Flows, discussing the orchestration patterns and not ESB. How is it possible to have an optional core? Is it really a core? Yes, it is. First of all, Enterprise Business Flows (EBF), which are offered as task-orchestrated services, are the closest entities that represent our business and how we understand it. No wonder most of the IT initiatives related to SOA are carried out by the BPEL implementations (since Oracle 10g), despite the service's nature, their MEPs (synchronous or asynchronous), and the necessity of orchestration in general. The telecommunication primer is pretty common as seven...