Date Added: Jan 2012
Network virtualization provides a promising way to overcome Internet ossification. A major challenge is virtual network mapping, i.e., how to embed multiple virtual network requests with resource constraints into a substrate network, such that physical resources are utilized in an efficient and effective manner. Since this problem is known to be NP-complete, a variety of heuristic algorithms have been proposed. In this paper, the authors reexamine this problem and propose a virtual network mapping framework, ORS TA, which is based on Opportunistic Resource Sharing and Topology-Aware node ranking. Opportunistic resource sharing is taken into consideration at the entire network level for the first time and they develop an online approximation algorithm, FFA, for solving the corresponding time slot assignment problem.