Quality of Service Management in IP Networks through Dynamic Service Rate Reconfiguration

Abstract

The DiffServ architecture provides a scalable mechanism for QoS introduction in an IP network. The idea of DiffServ is based on the aggregation of traffic flows at an ingress (or egress) point of a network and the IP packet marking for distinct priority flows, according to several classification criteria. In this paper the problem of the improvement and fairness of absolute QoS provisioning to paths established along a DiffServ network on a per router basis is considered. Specifically, the dynamic service rate reconfiguration problem of a router's output link is formally defined, mathematically formulated and solved by means of efficient heuristic algorithms, providing good solutions in reasonable time. Two versions of the problem are addressed. First, a confined version, which exploits the available resources of service classes in order to improve QoS characteristics of the problematic flows. Second, an extended version of the problem, in which the strict constraints of the lower classes are relaxed in order to strictly meet the absolute QoS requirements of the higher order service classes.