SRAN: Scaling Named Data Networking via Map-and-Encap

Tianyuan Yu, Sirapop Theeranantachai, Lixia Zhang

Network routing scalability is hard to achieve when forwarding state is driven by external entities such as end users or multicast groups. Named Data Networking (NDN) faces this challenge acutely: it fetches data by name, which ties forwarding state to an unbounded number of application name prefixes. This paper presents SRAN, a scalable routing and forwarding architecture for NDN. Building on the Map-and-Encap principle, SRAN separates name-prefix reachability from topological reachability by mapping prefixes to egress routers at the network edge. Consequently, the network core routes and forwards based solely on topological connectivity. SRAN extends this mapping to support multicast by adapting Bit Index Explicit Replication (BIER), encoding prefix-to-multiple-egress mappings as a BitString to enable stateless multicast delivery. Implemented on the NDN substrate, SRAN leverages NDN's native security and dataset synchronization for secure routing and prefix-state dissemination, requiring no additional protocol. Evaluation on representative Rocketfuel topologies confirms that the network forwarding state scales with the topology rather than the application-prefix count, and adapts to prefix changes in real time with minimal dissemination overhead.