MIB containing event and alarm information.  The MIB contains
tables for events and alarms, and defined notifications for
events and alarms.

nevtEventTable.  Table with the last number of events.  The
event table contains the events that are sent as SNMP
notifications.  These events indicate change of alarms, or
change in other tables defined in other MIBs, that uses the
mechanism in this MIB to notify a table change.  If a
notification receiver misses notifications, it can retrieve
the lost notifications from this table.

nevtAlarmTable.  Table with all active alarms, and the last
historic alarms.  The alarm table holds all active alarms,
and possibly also a number of the last cleared alarms.

nevtActiveAlarmTable.  Table will all active (non-clear)
alarms.  The active alarm table holds only the active
alarms.