An on-demand off-path cache exploration based multipath forwarding strategy

Abstract

Information-Centric Networking (ICN), such as Named Data Networking (NDN), intrinsically supports multipath forwarding and in-network caching. In order to take full advantage of both multipath forwarding and in-network caching, it requires sophisticated coordination among consumers, publishers and in-network caches for consumers to learn the fine-grained packet-level cache reachability information. The complexity introduced by the coordination as well as the cache organization hinders the full potential of NDN. Network coding enabled NDN architecture, referred to as NC-NDN, was proposed to significantly simplify the coordination design. However, the NC-NDN proposed so far only exploits on-path caches, which leaves much room for performance improvement. This work enhances NC-NDN with an On-demand Off-path Cache Exploration based Multipath Forwarding strategy, dubbed as O2CEMF, to make the best of the multipath forwarding to efficiently utilize off-path cached content. Under O2CEMF, each network node reactively explores nearby off-path cacheswhen consumers begin to request a generation of content and then maintains the reachability information at the more coarse-grained generation level of granularity instead. Then each consumer can simultaneously retrieve diverse content segments from the original content publisher(s) and the explored capable off-path caches. Our experimental studies validate that our proposed O2CEMF strategy improves the content delivery performance in terms of the average cache hit ratio, the average hops that an Interest traverses, and the average time for retrieving content at an affordable cost as compared to that in the present NC-NDN without exploiting off-path caches.