If you require a high level of fault tolerance, you can implement a duplexed, geographically distributed ICM configuration. In this type of configuration, an additional A-Link set must be provisioned to each location. For example, you might have Side A of the Central Controller in one city and Side B in another city. This configuration is shown in Figure 3-5 . The geographically distributed configuration adds protection against disasters that might remove one side of the ICM system from service.
Manual intervention is required.
Figure 3-6 represents a high level view of how ICM software fits into the Concert network. The Concert NIC, the ICM CallRouter, and the ICM logger are all on one workstation node. However, the Logger can be configured to run standalone if greater performance is desired. The CallRouter processes the new call request and returns a destination label through an OPI connect request. The NIC translates the connect request into a destination response and sends it to the CIS Gateway through the Concert Gateway using a GSP message.