A system and method for communicating first data packets having a first quality of service over a network system designed for communicating second data packets having a second quality of service. The network system includes a plurality of network nodes, where each of the network nodes includes a network switch. The first data packets are switched from each of a plurality of network switch input ports to a dedicated output port of the network switch. Network node congestion control is applied to the first data packets at the dedicated output port to selectively accept or discard the first data packets in accordance with their respective quality of service acceptance principles. Those of the first data packets that were accepted are multiplexed into one or more virtual paths having common output port destinations, and the virtual paths are input into a dedicated input port of the network switch. The virtual paths at the dedicated input port are switched to output port destinations of the network switch identified by the common output port destinations.