PDF of this tutorialDuring the mid-1980s, regional Bell operating companies (RBOCs) began requesting features that met the following objectives:
- rapid deployment of services in the network
- vendor independence and standard interfaces
- opportunities for non–RBOCs to offer services for increased network usage
Telcordia Technologies responded to this request and developed the concept of Intelligent Network 1 (IN/1), shown in Figure 3.
Figure 3. Intelligent Network 1 (IN/1)
The introduction of the IN/1 marked the first time that service logic was external to switching systems and located in databases called service control points (SCPs). Two services evolved that required IN/1 service logic—the 800 (or freephone) service and the calling-card verification (or alternate billing service [ABS]). Because of the service specific nature of the technology, these services required two separate SCPs. To communicate with the associated service logic, software was deployed in switching systems. This switching system software enabled the switching system to recognize when it was necessary to communicate with an SCP via the SS7 network.
With the introduction of the SCP concept, new operations and management systems became necessary to support service creation, testing, and provisioning. In the above figure, note the term "service-specific management systems" under the box labeled "service management system." This means that the software-defined hooks or triggers are specific to the associated service. For example, an 800 service has an 800-type trigger at the switching system, an 800-service database at the SCP, and an 800-service management system to support the 800 SCP. In this service-specific environment, the 800-service set of capabilities cannot be used for other services (e.g., 900 service). Although the service logic is external to the switching system, it is still service specific.
Figure 4. AIN Architecture
At first glance, Figure 4 looks similar to Figure 3. However, there is one fundamental difference. Notice the wording "service-independent management systems" under the box labeled "service management system." Now, following the IN/1 800 service-specific example, the AIN service-independent software has a three-digit trigger capability that can be used to provide a range of three-digit services (800, 900, XXX, etc.) as opposed to 800 service-specific logic. Likewise, the SCP service logic and the service management system are service-independent, not service specific. AIN is a service-independent network capability!
