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Software-defined networking(SDN) enables the network virtualization through SDN hypervisors to share the underlying physical SDN network among multiple logically isolated virtual SDN networks(v SDNs),each with its own controller.The v SDN embedding,which refers to mapping a number of v SDNs to the same substrate SDN network,is a key problem in the SDN virtualization environment.However,due to the distinctions of the SDN,such as the logically centralized controller and different virtualization technologies,most of the existing embedding algorithms cannot be applied directly to SDN virtualization.In this paper,we consider controller placement and virtual network embedding as a joint vS DN embedding problem,and formulate it into an integer linear programming with objectives of minimizing the embedding cost and the controller-to-switch delay for each v SDN.Moreover,we propose a novel online vS DN embedding algorithm called CO-v SDNE,which consists of a node mapping stage and a link mapping stage.In the node mapping stage,CO-vS DNE maps the controller and the virtual nodes to the substrate nodes on the basis of the controller-to-switch delay and takes into account the subsequent link mapping at the same time.In the link mapping stage,CO-v SDNE adopts the k-shortest path algorithm to map the virtual links.The evaluation results with simulation and Mininet emulation show that the proposed CO-v SDNE not only significantly increases the long-term revenue to the cost ratio and acceptance ratio while guaranteeing low average and maximum controller-to-switch delay,but also achieves good v SDN performance in terms of end-to-end delay and throughput.
Software-defined networking (SDN) enables the network virtualization through SDN hypervisors to share the underlying physical SDN network among multiple logically isolated virtual SDN networks (v SDNs), each with its own controller. V SDN embedding, which refers to mapping a number of SDNs to the same substrate SDN network, is a key problem in the SDN virtualization environment. Due, due to the distinctions of the SDN, such as the logically centralized controller and different virtualization technologies, most of the existing embedding algorithms can not be applied directly to SDN virtualization.In this paper, we consider controller placement and virtual network embedding as a joint vS DN embedding problem, and formulate it into an integer linear programming with objectives of minimizing the embedding cost and the controller-to-switch delay for each v SDN. Moreover, we propose a novel online vS DN embedding algorithm called CO-v SDNE, which consists of a node mapping stage and a link mapping stage.In the node mapping stage, CO-vS DNE maps the controller and the virtual nodes to the substrate nodes on the basis of the controller-to-switch delay and takes into account the subsequent link mapping at the same time. the link mapping stage, CO-v SDNE adopts the k-shortest path algorithm to map the virtual links. the evaluation results with simulation and Mininet emulation show that the proposed CO-v SDNE not only greatly increases the long-term revenue to the cost ratio and acceptance ratio while guaranteeing low average and maximum controller-to-switch delay, but also achieves good v SDN performance in terms of end-to-end delay and throughput.