Anchor point redundancy support for pseudowire subscriber logical Interfaces

Stateful anchor point redundancy support is provided for pseudowire subscriber logical interfaces by the underlying redundant logical tunnel interface in active-backup mode. This redundancy protects the access and the core facing link against anchor Packet Forwarding Engine failure. Both transport and services logical interfaces created for the pseudowire subscriber logical interface are stacked on the underlaying redundant logical tunnel control logical interface. This logical interface stacking model is used for both redundant and non-redundant pseudowire subscriber logical interfaces.