C-LGV: A novel cooperative caching scheme for P2P caches

For an ISP (Internet Service Provider) which has deployed P2P caches in more than one AS (autonomous system), cooperative caching which makes their caches cooperate with each other can save more cost of carrying P2P traffic than independent caching for the ISP. However, existing cooperative caching schemes only use objects´ popularity as the measurement to decide which objects should be cached, and cost on intra-ISP links that has great impact on the benefits of cooperative caching is not considered. In this paper, we propose a novel cooperative caching scheme named C-LGV (Cooperative, Lowest Global Value). C-LGV uses cost on intra-ISP links as well as objects´ popularity to evaluate each object´s global value (a new concept defined to estimate the benefits of caching or replacing an object), and objects with the lowest global values will be evicted when each local cache needs to replace its cached contents. Results of both synthetic and real traces driven simulations indicate that C-LGV can reduce the cost of carrying P2P traffic by at least 23% compared to existing cooperative caching schemes.