This counter tracks the number of downstream packets that exceeded the maximum downstream bandwidth allowed by the QoS profile for this Sid and were consequently dropped by the rate-limiting process. Admins use it to identify subscribers whose downstream traffic regularly overshoots their provisioned rate, causing real packet loss rather than just delay. For example, a customer complaining about choppy video streaming whose Sid shows a rapidly increasing cwdxQosMaxDownBWExcessPackets is likely being rate-limited because their traffic exceeds the downstream cap in their QoS profile.