Example Intra-Zone and Extra-Zone Integration Architectures

One of the books I often recommend to people who are new to message based integration solutions is "Enterprise Integration Patterns" by Hohpe and Woolf. Visio stencils that contain shapes for the various patterns and pattern components can be downloaded from the book's website. The following diagram (click it to view a larger version) tries to do a few things...

First, it states SIF architecture in terms of Enterprise Integration Patterns (EIP). The second thing it does is illustrate one possible way to implement extra-zone services using EIP concepts. The third thing it does is to begin calling out the business and use cases for intra-zone versus extra-zone services, which are duplicated in the text below.

Intra-Zone Business and Use cases
1. Applications wish to exchange data on a regular basis
2. Applications are contained within a single enterprise, or closely related enterprises
3. Guaranteed delivery is desired or required
4. Central administration of message flow is desired or required
5. A collection of applications wish to share the same data

Extra-Zone Business and Use cases
1. Applications wish to exchange data on an infrequent basis
2. Applications have minimal or no organizational ties
3. Guaranteed delivery is not required
4. Central administration is not required
5. Two applications needs to share specific data