Research And Realization For Distributed And Protocol-Oblivious Network Virtualization System

Network virtualization is a efficient way to provide logically-isolated virtual net-works over a shared substrate network.Combing network virtualization with software-defined network(SDN),it will greatly improve the flexibility of the networks.How-ever,the network virtualization can never be accomplished without an efficient network virtualization hypervisor(NVH)system,whose scalability and availability are very im-portant to the system.Since an NVH with centralized architecture cannot guarantee high-availability and high-scalability,we decide to realize a distributed NVH system.Moreover,with the help of protocol-oblivious forwarding(POF),we can develop a protocol-independent distributed NVH system,which will greatly improve the scalabil-ity,availability and flexibility of the NVH system.In this thesis,we firstly focus on the realization of the protocol-independent NVH system.Leveraging POF and the distributed architecture of ONOS,we will develop a protocol-independent NVH system,namely DPVisor,which can provide virtual software-defined network(vSDN)slicing with superior network programmability.We will verify that DPVisor has a good performance scalability and availability through the experimen-tal comparisons with ONVisor(i.e.,an OpenFlow-based ONOS benchmark)in terms of the message processing latency,message processing throughput and failure recovery time.Then we will analyze the system performance bottleneck through the consistency model of distributed data synchronization.The experiments verify that our proposed local-cache based scheme can greatly improve the message processing throughput of distributed NVH systems,while the data consistency among NVH instances is still maintained well.Moreover,we work on the virtual network embedding(VNE)algorithms for the distributed NVH systems.Considering the realization principle of the DPVisor,we take the TCAM resource on the nodes and bandwidth resource on the links as constraints and limit the number of NVH instances used when embedding vSDN controller to avoid unnecessary east-/west-bound communication overheads.As a result,we formulate an integer linear programming(ILP)to solve the problem exactly.Then we propose an efficient heuristic to reduce the time complexity based on global resource capacity(GRC).The simulation results suggest that our proposed algorithms can embed vSDNs cost-effectively and significantly outperform the existing scheme based on GRC.