Description: This attribute specifies the variance values for high and low metric ranges, for each class of service (COS). A variance value is the maximum allowed difference in metric between the best path and the second path, as a percentage of the best path metric. High and low metric ranges are defined for each COS by the delayMetricRangeBoundary and tputMetricRangeBoundary attributes, and refer to total path metrics.

When a variance value for a certain COS and metric range is set to the default value of 0, only equal metric paths can be used under that COS when the best path metric is in that range. When it is set to a value greater than 0, an alternate path which is safe (that is, non-looping) and which has a metric within this percentage of the best path metric can be used as a multipath.

The special value of 9999 signifies an infinite variance, so that any safe alternate path may be used in addition to the single best path, regardless of its metric.