Research On Virtual Network Embedding Mechanism Based On Space Division Multiplexing Elastic Optical Network

Network virtualization technology is one of the key technologies for cloud computing and data center business.Network virtualization embedding is an important technology for network virtualization,which realizes the allocation of physical resources for received virtual networ-k requests.In this process,how to improve the utilization of physical network facilities and reduce the blocking rate of virtual network requests is the main challenge in this process.This thesis mainly studies the virtual network embedding mechanism based on space division multiplexing elastic optical network(SDM-EON),and the main problems are as follows:1.In the process of node embedding,how to filter out high-quality physical nodes for the current virtual network,and lay a good physical foundation condition for subsequent link embedding,that is the node embedding problem.2.In the process of link embedding,how to make full use of physical link spectrum resources and leave more spectrum resources for subsequent virtual network requests while completing this virtual network embedding,that is the link embedding problem.3.In the process of virtual network embedding,how to maximize the security of the service while r~educing the cost of service providers,that is,the virtual network embedding survivability problem.In response to the above questions,the main tasks of this topic are as follows:1.Aiming at the problem of node mapping in virtual network embedding in SDM-EON scenario,an evaluation model of high matching node mapping degree for virtual network request was proposed.By comprehensively considering the overall resource status of optical transponder and adjacent links of physical nodes,better screening of physical nodes is realized,which lays a better physical resource foundation for link embedding.The simulation results show that under different service intensities,the blocking rate and resource utilization rate are different when the impact degree of each influencing factor is different.For example,when the traffic intensity is relatively large,the blocking rate is about 5%lower when only considering the factors of optical transponder than that of adjacent links.2.Aiming at the link embedding problem in virtual network embedding in SDM-EON scenario,a virtual link embedding scheme based on distance adaptation is proposed.The distance adaptive method is used to select the most suitable transmission mode according to the length of the distance.The simulation results show that the blocking rate of the virtual network embedding scheme considering distance adaptation is about 20%lower than that of the embedding scheme without distance adaptation.3.In the aspect of virtual network embedding survivability,a composite protection measure combining dedicated backup and shared backup is proposed.By using the virtual network embedding mechanism based on fault avoidance,the screening of "important nodes" and"important links" in the network with relatively large influence is realized.The simulation results show that different nodes and links have different impacts on the results of virtual network embedding,such as the blocking rate of virtual network embedding when node 6 fails is about 2%higher than that when node 13 fails.Therefore,according to this scheme,"important nodes"and"important links"can be screened,and targeted protection can be performed.