This counts how many times this circuit's path through the Cascade network mesh has been rerouted -- recalculated to a different set of hops and nodes -- typically triggered by a trunk or node failure along its original path. An admin watching this counter climb repeatedly for the same circuit, rather than stay flat, knows that circuit's path is unstable, perhaps riding a trunk that keeps flapping, even if the circuit itself never fully drops. For example, a cktRerouteCnt that increases by 5 in a single day points to five separate upstream path failures that each forced this PVC to find a new route.