Threshold violation

A KPI is considered to be in a violation state when it breaches the limits of traffic volume data for a specific number of times according to the configuration settings.

Threshold type
The severity of a violation is decided based on the violation against either on the upper or lower limit that is configured for a threshold.
  • If the threshold is configured to check for Over, then severity is determined as:
    • If KPI value is greater than or equal to the Upper Limit, then the severity is Critical.
    • If the KPI value is greater than or equal to the lower limit, but not exceeding the upper limit, then the severity is Major.
  • If the threshold is configured to check for Under, then severity is determined as:
    • If the KPI value is lesser than or equal to the upper limit, but not dropping below the lower limit, then the severity is Major.
    • If KPI value is lesser than or equal to the lower limit, then the severity is Critical.
  • If the threshold is configured to check for Band, then severity is determined as:
    • If the KPI value is greater than or equal to the upper limit, then the severity is Critical.
    • If KPI value is lesser than or equal to the lower limit, then the severity is Critical.

For example, if the limit type is Over, and the traffic volume data is greater than the upper limit, the severity of the threshold is set to Critical. If the traffic volume data is greater than the lower limit, the threshold severity is set to Major.

The following table summarizes how a threshold severity is set to either Major or Critical for different limit types:
Table 1. Threshold severity for limit types
Limit Type Scenario Severity
Over Traffic volume data greater than the upper limit Critical
Traffic volume data greater than the lower limit Major
Under Traffic volume data lesser than upper limit Major
Traffic volume data lesser than the lower limit Critical
Band Traffic volume data greater than the upper limit Critical
Traffic volume data lesser than the lower limit
Note: For limit type Band, the severity is always set to Critical for any threshold violation scenarios.

Exiting a threshold violation

Exiting from a violation state is the action of setting the severity of an event to CLEAR. The severity is cleared after a KPI goes into a non-violation state. The threshold at which an event is raised then is cleared.

Non-Violation -> Major Violation -> CLEAR -> Non-Violation
Or
Non-Violation -> Critical Violation -> CLEAR -> Non-Violation
Network Performance Insight® supports system generated auto clear. The following table shows, when the system can set the severity to CLEAR.
Table 2. Scenarios for CLEAR severity.

Table that shows scenarios when CLEAR severity occurs
Limit Type Current Severity Scenario New Severity
Over KPI is either in Major or Critical level Traffic volume data lesser than the lower limit CLEAR
Under KPI is either in Major or Critical level Traffic volume data greater than upper limit CLEAR
Band KPI is in Critical level Traffic volume data falls within the range of upper limit and lower limit CLEAR

If an existing threshold configuration is modified, by changing any of the configuration values such as limit type, upper or lower limit, number of events or disable the threshold, the system sets the severity to CLEAR.

For more information about the configuration steps, see Configuring Flow thresholds.