All SAP-level statistics are retained with an APS switch. A SAP reflects the data received regardless of the number of APS switches that has occurred. ATM statistics, however, are cleared after an APS switch. Therefore, any ATM statistics viewed on an APS port are only the statistics since the current active member port became active.
Physical layer packet statistics on the APS group reflect what is currently on the active member port.
Port and path-level statistics follow the same behavior as described above.
Any SONET physical-layer statistics (for example, B1,B2,B3,...) on the APS port are only what is current on the active APS member port.