Research On Cross-domain Mapping Algorithms Of Service Function Chain

Network function virtualization(NFV)decouples network functions from physical devices,which significantly saves Capital Expenditure(CAPEX)and Operational Expenditure(OPEX),attracting widely attention from both industry and academia.However,due to the demand of maintaining order correctness and satisfying location constraints of network functions'(NFs)in service request,network function providers face great challenges when mapping service function chains.On the one hand,current studies mostly focus on service function chain mapping(SFCM)in single domain,and a few algorithms for SFCM across multi-domain are complex and time-consuming.On the other hand,as an important indicator,power consumption has important significance for network function operators,but no scholars have studied the power consumption problem of service function chain mapping in multi-domain networks.Therefore,this thesis mainly analyzes these two issues in depth and proposes solutions.The main contributions and technological innovations are as follows:(1)For shortening the response time of mapping the service function chain request into substrate network and avoiding violating each domain's privacy,this thesis utilizes the full mesh aggregation technology to abstract the physical network into a smaller-scale abstract topology by collecting the public information.Based on the abstract topology,the abstract path between the source and the destination of the service function chain can be calculated,and the cross-domain mapping scheme of the service function chain may be generated on each abstract path.On each abstract path,this thesis proposes two service function chain segmentation schemes,which are averagely-partition and weightily-partition,so that the service function chain can be evenly distributed to each domain on the abstract path.In each domain,this thesis also proposes a sub-chain mapping algorithm that aims to reduce latency and achieve network load balancing.When the solution deployment is unsuccessful,the article proposes a feedback mechanism and then repartition the service function chain.Finally,when determining the physical deployments of each virtual network function on the service function chain,this thesis also designs algorithms to adjust the location of these deployments,thereby saving bandwidth overhead.The simulation test proves that the algorithm greatly reduces the response time of the service function chain mapping without violating the privacy of the multi-domain network,and the mapping cost and transmission delay of the mapping scheme are also optimized.(2)For the power consumption problem of cross-domain mapping of service function chain,this thesis systematically analyzes the power consumption of service function chain in cross-domain mapping for the first time,and proposes the integer linear programming model of the problem.And the thesis gives the method of solving the model in multi-domain network and analyzes its complexity.In addition,the article expands the point aggregation technology and proposes a service function chain cross-domain mapping algorithm aiming at saving energy.The simulation test proves that the algorithm can greatly reduce the power consumption and shorten the request response time of the algorithm without violating the multi-domain network privacy.