Abstract: A method and computer program product for scheduling network communication packets in a multimedia environment where different packet streams have reservations of network bandwidth to form packet flows. The present invention divides the packet scheduling function into distinct components that may be implemented as separate drivers in a layered driver environment as exists, for example, in the Microsoft Windows NT operating system. One component is called a conformer and will generate and assign to each packet in the packet flow at least one conformance time that signifies the earliest a packet may be sent and still conform to the network resource requirements associated with the flow. Many different conformance algorithms can be supported so that the best algorithm is used for a particular packet flow and the service requirements that it represents. Should it be necessary to actually hold a packet until the conformance time is met, a shaper component is used to delay the packets.