ns, a last resort approach can be screen scraping. Using a screen- scraping tool, the required data is pushed or pulled from the application with the user-interface. This technique can be helpful in limited circumstances, though relying on it can introduce considerable maintenance and performance issues. 12.2 Integration Techniques There are two major approaches to integration that are prevalent in the OSS space today. The first is a style known as "point-to-point." The second is commonly called Enterprise Application Integration (EAI), based on the technology used to achieve the integration. Figure 23 illustrates these approaches at a conceptual level. Chapter 6 - Integrating the OSS Platform App A App B Vendor App A Custom App A App B Connector Connector Figure 23. Integration Concepts Point-to-point integration dates far back in the history of IT. As its name infers, it entails the integration of applications in a pair-wise fashion. Application A's interfaces are joined to Application B's in a technical fashion distinct to that pairing. For example, some intermediary program is crafted that mediates between Application A's C++ API and Application B's database stored procedure interface. Application A may be joined to Application C as well, but in this case the technical approach may be quite different. It could use, for example, a file transfer-based interface. Enterprise application-based integration is based on the notion of a common technical approach to integration across the enterprise. This approach is oriented around a common middleware infrastructure that provides an integration "bus" or backplane among applications. Applications The Ultimate Guide to Building and Delivering OSS/BSS are connected to this bus via adapters or connectors that shield them from the other application interfaces attached to the bus. This EAI approach is discussed in more detail in the following sections. 12.3 Point-to-Point Integration As mentioned above, point-to-point integration is by the far the oldest integration approac