A packet is classified into a class. A priority value is assigned to the packet wherein packets in a flow are assigned priorities according to some probability distribution within some band. A determination is made, at a network device for a highest latency class, whether a sum of queued packet sizes of previously received packets having an equal or smaller latency class than the packet and larger or equal priority than the packet is larger than a threshold value. When the sum is larger, the packet is dropped, otherwise a determination is made whether a latency class of the packet is less than the latency class of the network device. When the latency class is not less, the packet is stored in a queue for the latency class. When the latency class is less, then the process is repeated until the packet is dropped or stored in a queue.