A two-layer intra-domain routing scheme for named data networking

Routing is undoubtedly the foundation of NDN's data transmission service. We propose a two-layer routing protocol for NDN [1], [2], which is composed of a Topology Maintaining (TM) layer and a Prefix Announcing (PA) layer. The underlying layer (TM) maintains the full topology of an NDN network domain and calculates the shortest-path trees. The upper layer (PA) provides content in two ways: active publishing and passive serving. However, solely adopting either of them will lead to the problem of scalability. We compare the efficiency and cost of the two methods, and evaluation results show that active publishing is much more efficient than the passive serving method in terms of triggered traffic, but actively publishing all the content will lead to Forwarding Information Base (FIB) explosion. Therefore, we further propose a popularity-based active publishing policy and arrive at a compromise between the active and passive methods. Moreover, we put forward several methods to aggregate FIB entries, and the FIB size shrinks effectively after aggregation. This routing protocol is compliant with the NDN characteristics and supports NDN multipath routing.