User manual

Wide Bank 28 DS3 - Release 2.4 July 2004 2-15
Product Description
LED Test and Status Indicators
Critical and Major/Minor Alarm Definitions
Table 2-2 lists the events that cause critical and major/minor alarms. Any one of the critical alarm
events cause the Critical Alarm LED to light red, activate the critical alarm relay contacts, and
record appropriate log entries. Any one of the major/minor alarm events cause the Major/Minor
Alarm LED to light red (major) or yellow (minor), activate the major/minor alarm relay contacts,
and record appropriate log entries. When the alarm event no longer exists, the LED and the relay
contacts revert to the non-active state but the log entries remain.
Line Code Violations and Bipolar Violations
Line Code Violations (LCV) are used to determine alarm events that are typically a result of
deteriorating transmission line integrity. The calculation of LCVs, and Bit Error Rate (BER) in
the Wide Bank 28 DS3 is as follows:
BPV (Bipolar Violations). The occurrence of a pulse of the same polarity that is not part of a
zero suppression signature.
EXZ (Excessive Zeros). A string of more than 3 consecutive zeros for E1 and DS3 data, or 7
consecutive zeros for DS1 B8ZS, or 15 consecutive zeros for DS1 AMI
LCV. Total number of BPVs and EXZs.
BER. Number of LCVs in time window divided by number of bits in time window.
LCVs are also used to determine when a DS3 switching event takes place (DS3 threshold).
SeeDS3 THRESHOLD on page 8-42.
NOTE: When DS3 protect is turned on and there is a bit error rate (BER) exceeding
1x10
-3
, the active Controller executes a protection switch to the standby Controller
regardless of the DS3 threshold setting.
Table 2-2 lists all possible alarm events. All alarms are recorded in the event log, which can be
accessed through the command line interface.