Research On File Distribution System Based On NDN Mechanism

In recent years,with the rapid development of computer network,the Internet has become an integral part of today's society.However,the data transmission and information security put forward higher requirements for Internet with the development of society.Named data network show its advantages of transmission speed and information security by its unique ideas and unique mechanisms.However,due to the mainstream status of IP network,named data network is difficult to popularize,these mechanisms are difficult to play an effective.In this paper,we will design and implement a set of file distribution system which can run on IP network in order to meet the needs of fast search and high speed download.The system is divided into user interaction layer,logic control layer,data persistence layer and built-in network layer.The built-in network layer is the core and key of the system,which includes NDN concept layer and IP adaptation layer.The NDN concept layer forms its own mechanism by refering the Named Data Network.In this paper,we will describes the NDN concept layer from four aspects: naming mechanism,routing forwarding mechanism,signaling packet mechanism and caching mechanism.The cache mechanism is an important part of the whole NDN concept layer,this paper set up a separate chapter to research cache strategy of Named Data Network.The IP adaptation layer is the bridge of the NDN conceptual layer to the actual IP network.This paper describes the adaptation layer of IP from three aspects,which are adaptive network construction,key data structure and communication mode.In the part of the cache mechanism,this paper first proposes the concept of data stream in the network,and analyzes the characteristics and the nature of the data stream.The cache Strategy based on data stream mainly applying to the Named Data Networking which has fixed topology.Each node in network decide whether cache the data by judging the current direction of data stream is whether same with the forecast direction.The result of simulation can prove that the cache strategy which is based on data stream can reduce cache space apparently,it also can remain the overhead and delay of network,but its response success ratio decrease little.