Collaborative Caching Algorithm Based on Request Correlation in Named Data Networking

How to efficiently utilize the finite storage space and cache content chunks in the content store poses challenges to the caching policy in Named Data Networking (NDN). Using the differentiated caching strategy, a collaborative caching algorithm is proposed based on the request correlation. In the scheme, the subsequent correlated content chunks are requested in advance to increase the hit ratio for content requesting. When making the caching decision, a two-dimensional differentiated caching policy combining the caching location and cache-resident time is proposed. According to the change of content activity, the caching location is pushed downstream hop by hop in the spatial dimension in order to spread popular contents to the network edge in a gradual manner, and the cache-resident time is adjusted dynamically in the time dimension. The simulation results show that the proposed algorithm can efficiently decrease the request latency, reduce the cache redundancy, and achieve higher cache hit ratio than other caching strategies.