Research On Routing And Forwarding Strategies For Content Centric Network

As Internet of Things,cloud computing and big data were widely used,the Internet traffic was growing explosively,especially,its scalability,mobility,management and security issues became more prominent.Modern Internet users only concerned about the content of information,while they do not care about the location of host,leading to the change of the routing mode with IP address identification in distinguishing servers with a specific contents.In order to fundamentally solve today's Internet problems,many international research institutions are exploring the form for future Internet.An information-oriented content center network(CCN)architecture has been proposed.CCN aims to replace the IP with the content block,which replaces the traditional Host-centric communication by content-centric communication pattern.Routing and forwarding strategies play a significant role in improving CCN performance.At present,CCN routing design is mainly based on broadcast or multicast,while CCN's several basic routing and forwarding strategies have their own advantages and disadvantages in communication overhead,hit rate and load.However,all of them are largely affected by the distribution of content popularity.In this thesis,we proposed the DRFP(Dynamic Routing Forwarding Based on Content Popularity)strategy with some improvements in the forwarding delay and other elements,combined with the shortest path priority and broadcast routing strategy.In addition,the introduction of the content popularity is also presented.Firstly,the basic structure and communication system of the content center network are introduced,and some CCN-based routing strategies in the current research field are compared and contrasted.Then,an improved routing policy based on broadcast and unicast dynamic translation is proposed.Once seek of FIB table fails,routing is converted from unicast to broadcast,meanwhile,the analysis of the content popularity is introduced in the routing optimization algorithm.On the basis of predicting the future popularity of the content,he touting nodes will broadcast the data packages which has a high popularity,and discard packages with low popularity when the load is too large.In this case,our method could improve the efficiency of forwarding and balance the loads.The method of forwarding delay calculation is also proposed based on content popularity.When broadcasting interest packages or data packages,routing nodes will set a shorter forwarding delay for important interest packages that are popular,and vice versa,set a higher forwarding delay for the low popularity of interest packages.The forwarding priority of data packages is set higher than interest packages.When the routing node receives a duplicate interest package or data package within the forwarding delay period,it will use the corresponding content package to resist this action.In addition,an time-variable TTL is added to the interest package,which has a larger value for the more popular content.In this thesis,the design of protocol packet type,node table structure and communication flow are described in detail.The simulations based on both ndnsim and MATLAB platforms are also performed to achieve an improved routing strategy with a full implementation process in CCN network communication model.Also,the results are compared with Multicast and shortest routing strategy.