Cabletron Systems 9H42X-XX 사용자 설명서
How Rising and Falling Thresholds Work
3-27
Alarm Configuration
The top portion of the window contains the device information boxes, as well as
the event index number and the event description; the log itself includes the
following fields:
the event index number and the event description; the log itself includes the
following fields:
Index
This index number is not the event’s index, but a separate
index that uniquely identifies this occurrence of the
event.
index that uniquely identifies this occurrence of the
event.
Time
Indicates the date and time of each event occurrence.
Description
Provides a detailed description of the alarm that
triggered the event: whether it was a rising or falling
alarm, the alarm index number, the alarm variable name
and object identifier (OID), the alarmSampleType
(1=absolute value; 2=delta value), the value that
triggered the alarm, the configured threshold that was
crossed, and the event description. Use the scroll bar at
the bottom of the log to view all the information
provided.
triggered the event: whether it was a rising or falling
alarm, the alarm index number, the alarm variable name
and object identifier (OID), the alarmSampleType
(1=absolute value; 2=delta value), the value that
triggered the alarm, the configured threshold that was
crossed, and the event description. Use the scroll bar at
the bottom of the log to view all the information
provided.
Each log will hold only a finite number of entries, which is determined by the
resources available on the device; when the log is full, the oldest entries will be
replaced by new ones.
resources available on the device; when the log is full, the oldest entries will be
replaced by new ones.
How Rising and Falling Thresholds Work
Rising and falling thresholds are intended to be used in pairs, and can be used to
provide notification of spikes or drops in a monitored value — either of which can
indicate a network problem. To make the best use of this powerful feature,
however, pairs of thresholds should not be set too far apart, or the alarm
notification process may be defeated: a built-in hysteresis function designed to
limit the generation of events specifies that, once a configured threshold is met or
crossed in one direction, no additional events will be generated until the opposite
threshold is met or crossed. Therefore, if your threshold pair spans a wide range
of values, and network performance is unstable around either threshold, you will
only receive one event in response to what may be several dramatic changes in
value. To monitor both ends of a wide range of values, set up two pairs of
thresholds: one set at the top end of the range, and one at the bottom.
provide notification of spikes or drops in a monitored value — either of which can
indicate a network problem. To make the best use of this powerful feature,
however, pairs of thresholds should not be set too far apart, or the alarm
notification process may be defeated: a built-in hysteresis function designed to
limit the generation of events specifies that, once a configured threshold is met or
crossed in one direction, no additional events will be generated until the opposite
threshold is met or crossed. Therefore, if your threshold pair spans a wide range
of values, and network performance is unstable around either threshold, you will
only receive one event in response to what may be several dramatic changes in
value. To monitor both ends of a wide range of values, set up two pairs of
thresholds: one set at the top end of the range, and one at the bottom.
illustrates such a configuration.