Network Virtualization Technology Research And Application Based On SDN

The popularization of mobile intelligent terminals has brought explosive growth in the number of Internet users in recent years,which makes network services and applications increasingly diversified and complicated.The traditional TCP/IP network architecture has been difficult to adapt to the current network development requirments.SDN,a new network architecture,and network virtualization act as important ways to solve the network impasse.To some extent,these technologies ease the situation where the network development is faced with the troubles.The question that firstly is discussed in the network virtualization is virtual network embedding.We adopt the reasonable and efficient strategy to make full use of the substrate network resources and make virtual network services more stable and reliable in the limited underlying network resources.Firstly,a mathematical model of virtual network mapping problem is established in the thesis.Based on the exsiting the two-stage algorithms,the new algorithm aims at maximization of utility of network resources.In this algorithm,the resource evaluation criteria takes account of the multiple attributes of the nodes such as CPU computing resources,link bandwidth resources and number of neighbour nodes.This algorithm is used with strategy of node repeatable mapping in the node mapping stage,which can reduce the path loss of some link mappings.Then another scenario where there are some nodes' failure in substrate network is also studied.Another new algorithm is based on the service flow priorities,which means that different services have different qualities of service.Services with low delay is adopted the scheme of link backup.Otherwise,the remapping scheme is used.Finally,in order to validate and analyze the feasibility and superiority of the two virtual network mapping algorithms,MNA-VNE,SFP-RVNE,proposed in the thesis,this thesis focuses on optimization of utility of network resources and the reliability of network respectively.And we build different virtual network mapping models based on OpenFlow and achieve results from network simulations.The final experimental analysis shows that the two algorithms have good performances in the virtual network request acceptance ratio,network revenue-to-cost ratio.