On Cooperative On-Path and Off-Path Caching Policy for Information Centric Networks (ICN)

Information Centric Networks (ICN) envisions a radical shift from existing host-centric networking of the Internet to a content centric networking. Caching is an important and integral part of ICN. In ICN, the requested contents that are downloaded from the original source are stored at intermediate on-path routers. With increase in similarity in the requests by multiple users, similarity of contents passing through edge routers increases. This leads to cache redundancy at the edge routers resulting in decrease in network performance. To improve the network performance in such kind of scenarios, we have proposed a co-operative caching policy in which the edge routers or on-path routers optimally store the requested ICN contents and are supported by a strategically placed central off-path cache router for additional level of caching. We have proposed a simple heuristic mechanism which can be used to offload and to optimally store the contents from the on-path routers to off-path central cache router. Through theoretical studies and simulations we have demonstrated that this cooperative scheme improves the performance of the network significantly in terms of cache duplication, delay and network usage. While we have presented the results for a typical campus network, similar results can be expected in larger Internet by clustering a group of on-path routers around some criterion and then allocating an off-path cache router at a nearby location to the on-path routers.