Deployment Strategy Research And Optimization Of The VEPC Virtual Network Functions

Network Function Virtualization(NFV)has greatly promoted the transformation of the mobile communication network architecture,especially the development of the 4G Evolved Packet Core(EPC)network to the virtual Evolved Packet Core(vEPC)network.In the vEPC network,traditional network functions are decoupled from the custom hardware.The physical resources of the underlying network and the decoupled Virtual Network Functions(VNF)are integrated into a resource pool that can be allocated on demand,thereby improving the flexibility and scalability of the vEPC network.This thesis studies two main problems in the implementation of vEPC network,namely the deployment of VNF on the underlying network and the data plane performance of VNF.At present,the research on VNF deployment algorithms is mostly two-stage algorithm which performs node mapping before link mapping,and lacks efficient one-stage deployment algorithm in the vEPC environment.In addition,resource fragmentation may occur due to limitations of physical resources,resulting in a situation that the total amount of physical network resources is sufficient,but there is not enough resources on each server to deploy virtual services.Aiming at this kind of problem,this thesis proposes a VNF deployment algorithm based on VF2 algorithm.Firstly,under the premise of satisfying the resource constraints,the algorithm analyzes the topology association relationship between the virtual network and the physical network,use the least physical node and the physical link to complete the deployment.Secondly,for the problem of physical network resource fragmentation,the connected-component theory is introduced to optimize the virtual network deployment location.Then combined with the comprehensive resource utility value designed in this thesis,the final deployment scheme is determined.The simulation results show that the proposed algorithm can effectively improve the number of virtual network deployments in resource-constrained physical networks,reduce the resource fragmentation of the physical network,and effectively improve the acceptance rate of user request.In view of the high performance requirements of vEPC in practical applications,this thesis studies the NFV acceleration technology,and analyzes the deployment architecture of VNF on common hardware from the bottom up.In the virtual forwarding layer,the DPDK and OpenvSwitch technologies are integrated and optimized,that is,the DPDK-OVS data forwarding plane is built in the virtual forwarding layer.After implementing the traditional OpenvSwitch and DPDK-OVS data planes,the experimental test platform is built,and the performance of the two data forwarding planes in network throughput,delay and packet processing capability is compared and analyzed.The experimental results provide a reference for the subsequent deployment of vEPC networks.