Subscriber interfaces are composed of a combination of two key technologies, subscriber interfaces and group interfaces. While the subscriber interface defines the subscriber subnets, the group interfaces are responsible for aggregating the SAPs. Subscriber Interfaces apply to the 7450 ESS and 7750 SR only.
Subscriber interface — An interface that allows the sharing of a subnet among one or many group interfaces in the routed CO model.
Group interface — Aggregates multiple SAPs on the same port.
Redundant interfaces — A special spoke-terminated Layer 3 interface. It is used in a Layer 3 routed CO dual-homing configuration to shunt downstream (network to subscriber) to the active node for a given subscriber. Redundant interfaces apply to the 7750 SR only.