Research On Network Architecture Design And Caching Mechanism In Information-centric Network

With the growing demand for content distribution in the network,the disadvantages of traditional TCP/IP networks are increasingly exposed,the future Internet architecture which named ICN(Information-Centric Network)has been proposed.ICN evolutes from the host-centric IP architecture to a data-centric one,which can facilitate in-network caching for universal content caching in every internal network node,so that it can improve the efficiency of content distribution and reduce access delay.Moreover,since content delivery in ICN is performed in a connectionless manner which is routed-by-name,ICN can support mobility easily.However,the researches of network architecture for ICN propose a clean-slate architecture as a global replacement for current IP-based Internet,which comes with two significant drawbacks.The first problem is that in the whole network,the poor performance of the routing based on content name induces the feasibility problem,so that it is difficult to deploy this new network architecture in a short time,but for the content distribution-based network environment,there are some issues in TCP/IP network.The second problem is that in the WLAN,the mobile user in the ICN needs to resend the request to retrieve the unreceived content,which results in long handoff latency.Meanwhile,due to the storage space of the router is limited,efficient caching mechanisms which can optimize the cache performance of the architecture is worthy of studying.In recent research works,a lot of reactive caching schemes have been proposed in the ICN architecture.However,there are issues about caching redundancy with these reactive caching schemes,which cannot reduce the delay of handover and retriving content for mobile users.In this paper,we propose a new network architecture and caching schemes to address above issues.The main contributions of this paper can be summarized as follows:(1)Aiming at the feasibility of ICN architecture research,we propose a new architecture called CAIP(Caching Anywhere in IP networks).In our proposed architecture,we define a new IPv6 extension header to carry the content identifier,which can make legacy IP packets content-aware.The new proposed routing scheme integrates IP routing lookup and cache index lookup together,and the new reliable transmission scheme separates hop-by-hop acknowledgment and forwarding,which can be forward compatible with IP protocol and inherit proven advantages from ICN.Finally,seen from the evaluation results.CAIP can provide significant performance improvement in terms of access delay and traffic load.(2)Aiming at the caching mechanism of CAIP architecture,we propose a reactive cooperative caching scheme.In this scheme,the neighbor CAIP routers interact with the cache information,thus reducing the cache redundancy.When the cache space of the CAIP router is not enough,the local cache replacement strategy is adopted to maximize the total value of the local cached contents.Secondly,according to the factors of cache space,the link path and the content value,the local evicted contents are assigned to the neighbor CAIP routers,which can make full use of the storage resources.Finally,seen from the evaluation results,this caching mechanism can improve the cache hit rate and reduce the access delay.(3)Aiming at the mobile user mobility of CAIP architecture,we propose a wireless content-centric network architecture combining CAIP and SDN,which enables CAIP architecture supporting mobility.Each wireless LAN in the CAIP architecture is managed by a SDN controller centrally,which maintains the cached content and the Layer2 information.Moreover,we propose a proactive cache scheme based on CAIP-SDN architecture,which pre-cache the users' flow table enrties and the content data for mobile users.Finally,the simulation results prove that this proactive cache scheme based on CAIP-SDN architecture can significantly reduce the handover delay of mobile users.