A Research On Cache Mechanism Of Future Network

With the constant rise of new communication services and applications such as mobile Internet, the existing TCP/IP architecture shows a certain degree of ossifications. To solve the problem, content-oriented future network architecture arises at the historic moment. The information-centric networking(ICN) provides a network infrastructure service that is better suited to today's network(especially in content distribution and mobility). In content-centric networking(CCN), each node can cache the content object, which makes the caching become an inherent part of the network architecture. Therefore, the importance of network caching has gradually been highlighted.As we know, the network caching mechanism mainly includes two aspects, cache decision policy and cache replacement policy. This thesis only focuses on the optimization of cache decision policy. At first, several common content-oriented future network architectures are described, especially the CCN approach and its key technologies including naming mechanism, type of packets and the node forwarding model. On this basis, the existing cache decision policy and cache replacement policy in ICN are summarized and analyzed, at the same time, the problems are pointed out. To solve the problems, a distributed cooperative caching scheme is proposed, this scheme decides the cooperative content routers(CRs) with labels and makes them work together to cache content using the cooperative allocation algorithm. Then, the performance of the proposed algorithm is verified by using ccnSim simulator. The simulation results show that this scheme performs well in improving the cache hit ratio and reducing the load on the server side. However, it performs slightly worse in the average round-trip time. Finally, a selective cooperation caching scheme, which combines non-cooperative caching with cooperative caching by introducing the node caching state, is proposed. Through the simulation experiments, we found that this scheme has a better performance in improving cache hit ratio, reducing the network load and the average round-trip time.