This is a cumulative byte count transmitted through this specific QoS queue. Dividing the delta of this counter by elapsed time gives the actual throughput a given QoS rule is achieving, which an admin checks against that rule's configured cdmipQosRulesMaxBw to see if it's fully utilized or under-used. For example, a queue capped at 512 kbps whose byte counts imply only 100 kbps actual throughput suggests the application using that rule isn't generating enough traffic to need the reservation.