Research On SDN Virtual Network Remapping Algorithm And ONOS Distributed Database

With the development of network services,the network operation and management can be complicated by traditional network.SDN is an emerging architecture that breaks the closed network framework and enhances the flexibility of the network.This architecture decouples the network control and data forwarding plane enabling services to be centralized control.Its flexible programming methods can also provide a good platform for the realization of network virtualization,and have a good inspiration for the direction of the future development of the network.Network virtualization is an effective way to solve the problem of network rigidity,which shields the complexity of the substrate network by providing only the resources needed by the tenants.Network virtualization not only reduces the operating costs of the network,but also has a good support for the SDN network architecture.Virtual network reconfiguration is conducive to make full use of the underlying resources and increase the revenue of the network.An effective remapping algorithm is the key to achieve this goal.The research topic of this thesis is SDN virtual network remapping algorithm,in the context of SDN combined with network virtualization,the main research aspects are as follows.Firstly,the basic structure and key technologies of SDN and ONOS controller are introduced.The research status of network virtualization technology is analyzed,then the common virtualization methods and network functions virtualization are presented.Secondly,by describing the issue of reconfiguration,a virtual network minimum cost remapping algorithm based on time prediction is proposed,which includes two parts: the virtual network mapping module based on sub-graph isomorphic search and the minimum cost virtual network reconfiguration algorithm based on predictive feedback.So that the system can maintain load balancing,while minimizing the cost of reconfiguration to receive more virtual network and improve network revenue.The algorithm is implemented in ONOS system.Then,conducting an in-depth study of the ONOS distributed database.Including the implementation of the underlying protocol,data query methods and efficiency,distributed modes and the processing of database transactions.Combined with ONOS based on the intent strategies,in the cluster working state,the batch computing tasks are designed and tested,and the results are analyzed.According to the distributed characteristics of ONOS,the reliability and efficiency of the controller are verified in the cluster environment by forcing the controller offline.Finally,the algorithm is simulated by the network topology generation platform,and the results are compared with the existing algorithms.The experimental results show that the virtual network reconfiguration algorithm has improved both the network cost and the network receiving rate.