Provision of quality of service using active scheduling

Active and programmable networks change the functionality of routers and switches by using agents and active packets. The authors present a new packet scheduling scheme called active scheduling to control and maintain QoS parameters in virtual private networks (VPNs) within the confines of adaptive and programmable networks. In active scheduling an agent on the router monitors the accumulated queueing delay for each service. To control and to keep the end-to-end delay within the bounds, the weights for services are adjusted dynamically by agents on the routers spanning the VPN. If there is an increase or decrease in queueing delay of a service, an agent on a downstream router informs the upstream routers to adjust the weights of their queues. This keeps the end-to-end delay of services within the specified bounds and offers better QoS compared with VPNs using static WFQ. An algorithm for active scheduling is described and simulation results are presented and compared with WFQ.