Verilink AS100 (896-502379-001) Product Manual - Manual (Page 68)

5-2 Access System Centum Series User Manual
Framing Errors. One or more frame alignment bit errors have been
detected. This does not mean that synchronization has been lost.
CRC6 Alar m. One or more CRC6 block errors have been detected. The
D4 framing does not include CRC6; Centum Series replaces that
parameter by counting the number of framing bit errors. The result is a
useful picture over time regarding D4 link performance.
BPV. Bipolar Violations have been detected. This usually indicates that
a very weak or overly strong signal is being received from the network.
ESF Statistics
Definitions Errored Second (ES). Any occurrence of a Loss of Frame or a CRC6
error in a one-second period.
Failed Signal State (FSS). Ten consecutive Errored Seconds.
Failed Second (FS). Each second during the occurrence of a Failed
Signal State.
Severely Errored Second (SES ) Three hundred twenty (320) or more
CRC6 errors in a one-second period.
Bursty Errored Second (BES). More than one but less than 320 CRC6
errors in a one-second period.