Cabletron Systems CBU-NM, User Manual

Page: 25 / 108

CBU-NM
User Manual
ii 80-60100000-02 3–4
The Alarm Database stores the following information:
•
The device’s Poll and channel numbers.
•
The device’s name and product type, both extracted from the
Network Database using the Poll number contained in the alert.
•
The alert’s time and date of arrival.
•
The nature of the alert, stored internally as a number (see
Section
13.3.3 - Device alarm codes).
•
Whether or not the alarm has been acknowledged.
This information can be viewed through the Alarm windows (see
Section
3.4 ).
3.3.3 Unknown Device / Unrecognised Alert alarms
These two alarms show that an alert message could not be processed
properly - either the poll number is not in the Network Database, or the
device type is inconsistent with the alert received.
In either case, the alarm is still presented in the usual way, but the filters
treat it as being of type
Unknown Device or Unrecognised Alert rather
than as the type of alert received (eg Performing Backup).
An Unknown Device alarm is generated if a valid message contains a
Poll number for which there is no entry in the Network Database. The
device name is then shown as ‘Unknown Device’.
An Unrecognised Alert alarm shows that the Device type is wrongly
specified in the Network Database. PCNC knows which alert messages
can be produced by each device type, since this is defined in the file
PCNC0003.DLL. From the Network Database, it knows which device
types correspond to which Poll numbers. Thus PCNC can check the Poll
number contained in the alert against the alert message itself. If it thinks
an alert has come from a device that should not have been able to
produce it, PCNC generates an
Unrecognised Alert alarm.
For example, if PCNC received the alert message ‘ 00102-1: ALERT
Link down
’ but the Network Database had device number 102 defined
as a KBU 64, PCNC would create the Unrecognised Alert alarm. This
is because PCNC knows that KBUs do not generate
Link down alerts.
If the Network Database did not contain a device with Poll number 102,
PCNC would generate the
Unknown Device alarm.