The port-based virtual scheduling mechanism takes the native packet-based accounting results from the policer or queue and adds 20 bytes to each packet to derive the frame-based offered load of the policer or queue. The ratio between the frame-based offered load and the packet-based offered load is then used to determine the effective frame-based CIR and frame-based PIR thresholds for the policer or queue. When the port virtual scheduler computes the amount of bandwidth allowed to the policer or queue (in a frame-based fashion), the bandwidth is converted back to a packet-based value and used as the operational PIR or the policer or queue. The native packet-based mechanisms of the policer or queue continue to function, but the maximum operational rate is governed by frame-based decisions.