Scalable Hardware Content Router: Architecture, Modeling and Performance

Current Internet is evolving with the gradual shift from the traditional host-to-host communication model to the new host-to-content paradigm, which will eventually lead to a network of caches. The novel Named Data Networking (NDN) has been proposed as a future Internet architecture to embrace this paradigmatic shift, where caching becomes an ubiquitous functionality available at each router. A router with the functionality of content caching, running on NDN mechanisms, is termed as an NDN-based content router. Previous researchers focused on software content routers (SCR), which leverage a commercial off-the-shelf computer to execute content caching/accessing and named-based packet forwarding. SCR can only achieve limited throughput, which is far below the speed requirements of modern routers. Facing this situation, in this paper, we propose a hardware-based content router (HCR), aiming at purchasing wire-speed processing. We design a physically concise architecture for decoupling the packet buffers in line cards from the content caches attached to storage cards, enabling separate management and optimization while facilitating a modular structure for smooth capacity upgrade in response to increasing storage utilization. For lowering the operating complexity and reducing the storage management cost, we choose to employ distributed caches working in a cooperated manner by using consistent hashing. We model several candidate storage organizing schemes and carry out theoretical analyses for comparison. Analytical and synthetic workload-driven results show that the consistent hashing scheme achieves high cache performance and low cost simultaneously.