Named data networking on a router: Fast and DoS-resistant forwarding with hash tables

Named data networking (NDN) is a new networking paradigm using named data instead of named hosts for communication. Implementation of scalable NDN packet forwarding remains a challenge because NDN requires fast variable-length hierarchical name-based lookup, per-packet data plane state update, and large-scale forwarding tables. In this paper, we review various design options for a hash table-based NDN forwarding engine and propose a design that enables fast forwarding while achieving DoS (Denial-of-Service) resistance. Our forwarding engine features (1) name lookup via hash tables with fast collision-resistant hash computation, (2) an efficient FIB lookup algorithm that provides good average and bounded worst-case FIB lookup time, (3) PIT partitioning that enables linear multicore speedup, and (4) an optimized data structure and software prefetching to maximize data cache utilization. We have implemented an NDN data plane with a software forwarding engine on an Intel Xeon-based line card in the Cisco ASR 9000 router. By simulation with names extracted from the IR-Cache traces, we demonstrate that our forwarding engine achieves a promising performance of 8.8 MPPS and our NDN router can forward the NDN traffic at 20 Gbps or higher.