An Effective Cost Optimized Provisioning Algorithm-(ECOPA) for Optical Networks

Multimedia applications present new challenges to the current networking technology. One of them is Quality of Service (QoS) requirement. Due to the increasing dynamics of traffic introduced by multimedia applications, dynamic and flexible QoS (Quality of Service) control is needed to ensure both QoS satisfaction and resource efficiency. Because integrated service networks are designed to support a wide range of traffic classes, which have different service requirements, developing metrics to evaluate them is complex. Optical networks provides Quality of Service (QoS), guarantees are also resilient to failures. Supporting QoS connections requires the existence of routing mechanisms that computes the QoS paths, where these paths satisfy the QoS constraints. Resilience to failures, on the other hand, is achieved by providing, each primary QoS path, a set of alternative QoS paths, upon a failure of either a link or a node. We aim at to minimize the total bandwidth reserved on the backup edges. The above objectives, coupled with the need to minimize the global use of network resources, imply that the cost of both the primary path and the restoration topology should be a major consideration of the routing process. It turns out that the widely used approach of disjoint primary, restoration paths is not an optimal strategy. Hence, the proposed approximation provisioning algorithms (ECOPA) construct a topology, and this topology protects a portion of the primary QoS path. This approach guarantees to find a topology with optimal cost which satisfies the QoS constraints.