User guide

Packet Over SONET Module Installation and User Guide 3-21
Configuring and Monitoring SONET Ports
Automatic Protection
Switching (APS)
An APS event occurs when the value of K1 or K2 changes. This
event is an input to the APS state machine, which is responsible for
handling the event and outputting the appropriate syslog message.
The LOS, LOF, AIS-L, SF BER, and SD BER events are also input to
the APS state machine.
Related SONET Overhead: K1,K2
Table 3-4: SONET Events (continued)
Event Description