Enhancing NDN feasibility via dedicated routing and caching

Named-data Networking (NDN) is a new networking regime for efficient content distribution. NDN employs name-based access and in-network caching to implement easy access to content. For that, NDN routers perform named-based routing, packet-level caching, and cache look-up, but these operations impose huge overhead on routers. To solve the feasibility issue of NDN router, in this paper, we propose an alternative architecture where caching and routing are separated. Routers are dedicated to packet routing while the cache server that is installed at every domain takes charge of in-network caching. Requests that have visited the cache server are marked and forwarded without further cache-lookup within the domain. This approach fundamentally relieves routers of heavy burden. Additionally, it introduces following benefits: (1) Huge amount of resource for caching is saved; (2) The effectiveness of in-network caching is improved; (3) The access delay of time-sensitive traffic is minimized. For the proposed architecture, cache look-up is performed via reserved links between the cache server and routers. Therefore, it is important to locate the cache server from the point of installation cost. We address how to place the cache server with the minimum cost, which is proved NP-complete, and present an approximation algorithm. Our simulation study shows that the proposed scheme reduces caching operations by up to 80% while achieving the same caching benefit only with 40% caching space.