Trie-Structure-Guided Compression, Allocation, and Mapping for Storage-Efficient IPv6 Lookup Pipelines

The rapid growth of IPv6 forwarding information bases (FIBs) strains high-speed routers. While trie-based algorithmic longest-prefix matching (ALPM) pipelines are widely deployed, existing designs emphasize trie compression but neglect pipeline memory utilization, limiting scalability under long IPv6 prefixes and imbalanced distributions. We present SCAMP-Trie, a trie-structure-guided approach that jointly addresses trie compression, node mapping, and pipeline memory allocation for storage-efficient IPv6 lookup. We propose a trie-based pipelined lookup model (TPLM) that captures the coupling among these dimensions through a unified storage efficiency metric. Leveraging the observation that nodes farther from leaf nodes are less frequent, we introduce an inverse-distance-based mapping principle, realized via a warning-line-based dynamic mapping algorithm and a metaheuristic search framework. To support flexible mapping while preserving compression, we codesign node structures including flexible child indexing, sub-trie next-hop compression, and half-size node storage. Evaluated on 36 real-world FIBs across four network scenarios, SCAMP-Trie improves average storage utilization by 4.0X and prefix capacity by 3.0 67.3X under the same memory budget. An FPGA prototype achieves 768 Gbps line-rate forwarding for 256-byte packets with a 240k-entry FIB, using only 41% of on-chip memory and 1% of logic.