The Queue Size. This must be greater than or equal to the fsQoSRandomDetectCfgMinAvgThresh and less-than/equal to fsQoSRandomDetectCfgMaxAvgThresh if Random Detection is enabled. This is depth in bytes of the queue being measured, at which a trigger is generated to the dropping algorithm. For the tailDrop(2) or headDrop(3) algorithms, this represents the depth of the queue, at which the drop action will take place. Other algorithms will need to define their own semantics for this threshold.