Editing Enterprise application integration (section)

=== Topologies ===
There are two major topologies: [[Hub and spoke|hub-and-spoke]], and [[Enterprise service bus|bus]]. Each has its own advantages and disadvantages. In the hub-and-spoke model, the EAI system is at the center (the hub), and interacts with the applications via the spokes. In the bus model, the EAI system is the bus (or is implemented as a resident module in an already existing message bus or [[message-oriented middleware]]).{{citation needed|date=February 2020}}

Most large enterprises use zoned networks to create a layered defense against network oriented threats. For example, an enterprise typically has a credit card processing (PCI-compliant) zone, a non-PCI zone, a data zone, a DMZ zone to proxy external user access, and an IWZ zone to proxy internal user access. Applications need to integrate across multiple zones. The '''Hub and spoke''' model would work better in this case.{{citation needed|date=February 2020}}