Dynamic inter-SLA resources sharing in differentiated services networks based on effective bandwidth allocation

The differentiated services (DiffServ) architecture has been proposed as a scalable traffic management mechanism to ensure Internet quality-of-service (QoS) without using per-flow resource reservation and per-flow signaling, but it sacrifices the ability to accurately configure the network devices and to efficiently utilize the network resources. To address the problem, the DiffServ model should be augmented with traffic engineering tools and dynamic resource allocation techniques. This chapter investigates dynamic resource allocation over a traffic engineered DiffServ network, where the multiprotocol label switching (MPLS) technique is used to establish a path-oriented environment in a DiffServ domain for efficient resource management. A bandwidth borrowing technique is developed for dynamic resource sharing among SLAs. It improves resource utilization on the time scale of a traffic flow lifetime, by exploiting the spare capacity of underloaded SLAs to admit traffic for overloaded SLAs. The call-level implementation of the bandwidth borrowing requires the effective bandwidth calculation for each traffic flow. For this purpose, the assured service is extended to provide loss probability guarantees and to derive an effective bandwidth expression based on such extension.