A method and apparatus to shape packet traffic rates of packets in-transit from a plurality of channels to a port, monitor a status of each queue, subtract a CIR from a port load value when an empty queue becomes active, add the CIR to the port load value when an active queue becomes empty, add a difference between an EIR and the CIR for a channel to a port excess value when a queue of the channel becomes excess, subtract the difference for the channel from the port excess value when the excess queue for the channel becomes not excess, calculate an oversubscription ratio based on the port load value and port excess value, calculate a shaping rate for each of the plurality of channels, and shape the traffic for each of the plurality channels using the shaping rate.