The following Figure shows the different types of threshold rules that might be defined.<br/>A MetricDefMeasureThresholdRule is a rule that defines the condition (raise or clear) to achieve to apply consequences when a threshold (MetricDefMeasureThreshold) is crossed or ceased to be crossed. It may behave in one of two different ways:<br/> • Either it provides attributes for various kinds of threshold logic definition (MetricThresholdRuleDefinition),<br/> • or it is defined by a derivation algorithm that represents a predefined logic that can be executed with parameters (PreDefinedMetricThresholdRule).<br/>A MetricThresholdRuleDefinition specifies the threshold range of values (lower and upper conformance target) with comparators (lower and upper comparator), tolerances and, grace periods, and a comparator. <br/>Each comparator is an operator that specifies whether MetricDefMeasureThresholdSet is crossed when it is above or below a conformance target. For example, a threshold may specify that when average lost packets indicator exceeds a value of 2000 and is under 3000, then the threshold is crossed.<br/>A PreDefinedMetricThresholdRule is a "blackbox" logic and is defined by a named predefined logic that can be executed with parameters. Therefore the PreDefinedMetricThresholdRule entity will hold the rule name, and the PreDefinedMetricThresholdRuleParam will define the parameters that are required for executing the PreDefinedMetricThresholdRule. As these parameters are often indicator specifications, they can be associated to the MetricDefMeasure entity.<br/>
