Research Of NDN Forwarding And Caching Strategy In Edge Network

With the continuous maturity of 5G and Internet of Things technologies,a large number of heterogeneous devices are connected to the edge network environment.At the same time,problems such as high content retrieval latency,single point of communication failure,and IP addresses running out are beginning to surface.Named data network(NDN)is a new network architecture,which adopts the communication mechanism of service push and subscription,and features such as self-named routing and in-network cache,which is an effective way to solve the above problems.At present,the research on the system architecture of NDN has begun to take shape,but the design of some modules is still deficient.This thesis mainly optimizes the NDN architecture of edge network from two aspects:forwarding strategy and caching strategy.Done in this thesis,the main work and innovation points are divided into the following several aspects:Firstly,this thesis improves the existing SDN-NDN architecture to solve the problems in the current edge network environment.Through adding node content popularity information and communication interface information in the control plane,the architecture can manage and maintain the node information and link information in the network globally.When there is an emergency in the network,the SDN controller can schedule and allocate resources according to the information,maintain the balance of traffic in the network and improve the stability of the edge network.Secondly,aiming at the problems such as delay of forwarding update and packet dropping that may exist in the edge network,an NDN forwarding strategy based on SDN is studied on the basis of the above work.At the same time,this thesis combines genetic algorithm and variable neighborhood search algorithm to research a new routing algorithm suitable for edge network environment.By optimizing the mutation link of genetic algorithm,the algorithm solves the local minimum problem that may appear in the original algorithm,and improves the convergence of the original algorithm.In addition,the algorithm also optimizes the Qo S parameters of the calculated path through traffic classification.Simulation results show that the forwarding strategy has more advantages in packet loss rate,and the routing algorithm studied in this thesis has about 20% improvement in time delay,energy consumption and other aspects compared with other routing algorithms.Finally,aiming at the problem that the internal network caching mechanism of NDN cannot adapt to the network state change of the edge network,a SDN-NDN caching strategy based on traffic classification is researched out.In this strategy,the business traffic in the edge network will be classified,and the SDN controller will conduct unified scheduling and processing for the cache in the network.In addition,this strategy also optimizes the traditional NDN caching strategy from three aspects: dynamic caching based on popularity,cache replacement based on traffic classification and cache association based on content warehouse.The simulation results show that compared with other NDN caching strategies,this strategy improves the cache occupancy by about 20?30%,and the global hit rate of this strategy is also more advantageous than other caching strategies.