Completing the Picture

So far we have been under the assumption (sometimes implicit and other times explicit) that the controlled switch is an ATM switch with ATM interfaces. But the architecture of multiservice switches is more general in order to allow multiple realizations of the model. Two more planes need to be added to present the complete framework, as shown in Figures 1-10 and 1-11.

Figure 1-10. Adaptation Plane

Figure 1-11. Management Plane

First, an adaptation plane is required to provide the multiple service access and adaptation to the core technology (see Figure 1-10). For example, if the controlled switch is an ATM switch, services such as Frame Relay and voice need adaptation to ATM.

This plane might or might not be present. In some cases, the adaptation is done in the Customer Premises Equipment (CPE).

Finally, a management plane allows the multiservice switches to be configured, controlled, and monitored, as shown in Figure 1-11.

The interface between the control plane and the switching plane is the SCI. The adaptation plane contains the partitioning function that partitions and manages resources in the different interfaces in the controlled switch.