Research On Congestion Control Strategy Of Named Data Network

In recent years,with the rapid development of the Internet,people have put forward higher requirements for the efficiency of data transmission in the network.The problems and drawbacks in the current Internet architecture have become increasingly prominent.The previous TCP / IP architecture follows the end-to-end There are many drawbacks in the communication mode.With the continuous development of technology,more and more new network architectures have emerged,and there has been a wave of research in the academic world.Named Data Networking(NDN),as a representative of the information center network,has appeared in people's vision..At present,the design of the architecture of the named data network is becoming more and more complete,and the research on the key problems that are common in the Internet architecture is still to be improved.Network congestion is the key to the design of network architecture and the key to whether the network can communicate efficiently.Network congestion is essentially a coordination problem of the supply and demand of network resources.In the process of data transmission,when the content transmitted in the network exceeds the upper limit that the network can accommodate,the supply and demand relationship is unbalanced,and network congestion will occur.How to effectively alleviate network congestion and enable normal data transmission is a key issue to be solved urgently in the development of the Internet.At present,the congestion control scheme adopted by NDN is mainly divided into two types: user-based congestion control and hop-by-hop congestion control mechanism.The former uses the timeout mechanism in the TCP / IP system architecture.When the request is not satisfied after a certain period of time,it is determined that a packet loss has occurred,and the rate of sending interest packets is reduced at the user end to ease the network.congestion.The latter is hop-by-hop congestion control during the route forwarding process,and the routing node adjusts the local request sending rate to restore the network state.Both of these congestion control mechanisms have some disadvantages.First of all,in terms of congestion detection,the timeout retransmission mechanism in the IP network is still used.Only after a timeout occurs,measures to reduce the rate of sending interest packets will be taken to make congestion control become Passive;secondly,a sliding window-based rate adjustment scheme in the IP network is adopted on the user side.Although it can alleviate network congestion to a certain extent,when the network is idle,there are no relevant measures to indicate how to use this part of idle bandwidth;The hop congestion control scheme adjusts the rate of interest packet transmission at the intermediate node,and does not consider a scheme to alleviate network congestion at the route forwarding level.This paper discusses the optimization of network congestion status in two aspects,user-side and hop-by-hop.According to the characteristics of the problem under consideration,this paper mainly uses the idea of early detection and early prevention to construct a network congestion detection mechanism,detect network traffic in real time,and make corresponding feedback,and propose a comprehensive congestion control strategy.On the basis of knowing the state of the network,at the user end,the forwarding strategy based on the ranking of the routing interface is adopted to adjust the network request sending rate and the intermediate routing nodes to adjust,so as to achieve the optimization of network performance.The research purpose of this article is that in the actual application environment,the Named data network can take advantage of its data transmission and avoid performance degradation due to network congestion,thereby contributing to the practical application of the Named data network.In this paper,a simulation experiment of congestion control strategy was carried out on ndn SIM.The comprehensive congestion control strategy proposed in this paper was compared with the congestion adjustment strategy currently adopted by NDN.The content hit rate and the total user hit rate have certain advantages,so as to achieve the purpose of improving the network content hit rate and alleviating network state congestion.