Dispersing Content Over Networks in Information-Centric Networking

Information-centric networking (ICN), a new network architecture for efficiently delivering content, has been widely investigated recently. In ICN, cache memory is implemented at each router, and content items are routed in the network by using content name as the locator determining the destination. The caching strategy that determines the content to be cached at each router strongly affects the cache hit ratio and flow hop length, and it is important to efficiently utilize limited cache resources by avoiding duplicated caching of the same content among routers located closely. In this paper, we propose a spatially dispersed caching (SDC), which is a caching strategy dispersing content by assigning a binary ID to each router and limiting the cache targets at each router to content with names whose hash value coincides with the router ID. Through computer simulations using backbone networks of actual ISPs in the United States, we show that the SDC improves the cache hit ratio by about 30%-170% compared with the case when caching content at all routers on the default path, and the SDC reduces the average hop length at cache hit by about 50%-90% compared with the existing caching strategies. Moreover, we show that the SDC improves the sustainable ratio of content acquisition in large-scale failures of routers by about 25%-200% compared with the existing caching strategies.