The Research Of Cache Management Mechanism And Cache Configuration Method For Content Centric Network

With the increasing expansion of the Internet and the change of applications, there is a series of questions existing in the current structure of the Internet which is characterized by “IP address as the center”, such as low efficiency, poor security, poor mobility etc. To solve these problems,a radical approach is to design the network architecture of ICN(Information Centric Network). Content Centric Network(CCN) is a widely concerned as the architecture of ICN. Wide in-network caching is an important function of ICN, so reasonable cache management mechanism and cache configuration mechanism play important roles in improving network performance.In the research of cache management methods in CCN network, in order to improve the network performance, the most existing research uses the independent cache management mechanism and the cooperative cache management mechanism. Because of caching content independently, the independent cache management mechanism may lead to information redundancy and the waste of resources. Because of sending cache information, cooperative mechanism will lead to large communication cost, and because of computing the cache location of content concentratedly, this method will load to poor scalability and can’t adapt to the scene of rapid and dynamic information changing. In order to solve these problems, this paper presents a cache management mechanism based on content-flow. It needs to divide the content-flow into several parts without redundancy according to caching model, and then combine with modified LCD and modified LRU to decide the cache location when the content return in the requesting path. Finally, the validity of the mechanism is verified by simulation.Content popularity refers to the probability of the requested content in the network, and reflects the popularity of the content. It can greatly improve the network performance that deciding the cache location of the content according to the content popularity. So this paper proposes another cooperative caching mechanism based on content popularity. Because it is difficult to statistic the content popularity, this mechanism statistics the content popularity through two methods, sending the information of content popularity by packets and carrying the information of content popularity by interest packets. Every network node need to maintain a content popularity statistics table which used to statistic the content popularity periodically. The ingress node statistic the content popularity according to the request from user, and the middle node upload the table according to the statistical result of lower level node. When the request hit and the content return, it decides to cache it or not according to the local content popularity statistic table. Finally, the validity of the mechanism in improving the efficiency of network performance is verified by simulation.In the research of cache configuration mechanism in CCN network, the most existing research always want to obtain the minimize network traffic based on fixed cache capacity, and ignore the affection of the different cache capacity. This paper proposes a cache configuration mechanism based on content-flow that repartitions the cache capacity based on the minimize network traffic. This method need to design the weight used to dividing the cache capacity according to flow-ratio, and then design configuration methods based on weight information. Finally, the validity and feasibility of the mechanism is verified by simulation.