This module is used to configure and manage the MPLS PW APS. The PW APS is a protection mechanism. When the working PW is faulty, the service carried on the working PW will be switched to the protection PW to protect the service. The more the PW APS groups are, the more network and device resources are occupied.To reduce resource consumption, multiple PW APS protection switchings are handled by one APS state machine. Multiple PWs share one APS state machine. Thisis called PW APS binding.