Differentiated services for network traffic using weighted quality of service is provided. Network traffic is queued into separate per flow queues, and traffic is scheduled from the per flow queues into a group queue. Congestion management is performed on traffic in the group queue. Traffic is marked with priority values, and congestion management is performed based on the priority values. For example, traffic can be marked as “in contract” if it is within a contractual limit, and marked as “out of contract” if it is not within the contractual limit. Marking can also include classifying incoming traffic based on Differentiated Service Code Point. Higher priority traffic can be scheduled from the per flow queues in a strict priority over lower priority traffic. The lower priority traffic can be scheduled in a round robin manner.