This read-only Counter64 is the current total number of out-of-order packets detected on this specific underlying Path. An admin uses this to determine whether reordering is occurring on one particular physical route, which can happen independently of packet loss and still degrade real-time traffic assigned to that path. For example, a specific underlying path showing a high out-of-order count, while its packet-loss counter stays low, tells the admin that path is unstable in a way that wouldn't show up if only loss were monitored.