Enhanced service differentiation for layered video multicast in differentiated service networks

An enhanced network service model for layered video multicast applications is presented for diffserv networks in this work, which consists of enhanced active queue management (AQM) and hierarchial priority marking. It is found from experiments that a straightforward application of the receiver-driven layer multicast (RLM) model to the diffserv network may perform poorer than to the best-effort Internet, since RLM applications could behave like unresponsive flows and conflict with diffserv active queues. To fix this problem, we present three sets of extended RED/RIO parameters as the enhanced AQM model, which is designed to be generally applicable to service protection as well as to support RLM traffic in diffserv networks. Furthermore, to take advantage of the priority service in diffserv networks, we present a priority marking model of RLM video layers that conform to the priority marking architecture of diffserv networks. It is shown by simulation experiments that the proposed network service enhancement model improves the stability of the join experiment and reduces the packet loss rate to support RLM traffic in diffserv networks.