Design And Research In Content Centric Networking Based On SDN

With the explosive growth of the internet users and content in recent years,existing IP network infrastructure has become a bottleneck on content delivery.A lot of duplicate content produce redundant traffic in the network,consuming too much network bandwidth,causing network congestion.American academia proposed CCN(Content Centric Network),as a solution to those problems.But CCN is a distributed network which nodes make decisions according to their limited local information.At the same time,CCN is now in the theoretical research and simulation phase,cannot be deployed in real networks.SDN(Software Defined Network)has the advantage of centralized management and control,easier access to the results of the optimization algorithm.The separation of control and forwarding in SDN,can just meet the needs of centralized management and control in CCN.This paper firstly design the new network architecture of CCN based on SDN on the whole.The new network can identify CCN packet,supporting content caching and CCN forwarding table.By extending the OpenFlow protocol,the controller can simultaneously support IP network and CCN protocol.This paper extends the controller function modules,including network topology management,route management,and content management modules.The new network architecture realized the name mapping,the structure of new mapping packet and caching mechanisms.Then,this paper proposed a collaborative strategy between the controller and cache node.Using the advantages of centralized control,the controller can make decision on cache placement,cache announcement and cache selection.This paper presents LCHR(Leave Cache based on Hop and Request)cache placing strategy that place cache on the key node closer to the users,who can get the cached content in a short time,without increasing redundant cache in network.Meanwhile,this paper put forward the OCS(Optimal Cache Select)cache selecting strategy considering the path overhead,path hops and remaining lifetime of cache as the factors for the selection of optimal cache from multiple cached copies.A lot of simulation verified the LCHR and OCS strategy have better performance compared with other strategies in network delay and cache hit rate.Meanwhile,statistics show that LCHR strategy is much better in the cache hit rate when consider the distance and the number of requests than a single factor.