Abstract
IP routing lookup Schemes using single-step TCAM used in core routers demand entries being sorted according to prefix lengths in descending order relative to TCAM addresses. The sorting operations related to addresses have disadvantageous affections to the entry updating speed and lookup continuity. This paper provides a novel IPv4/IPv6 dual-stack routing lookup method based on BSPL (Bi-search on Prefix Length), which using multi-step TCAM pipelining based on bi-search on prefix length. Its outstanding advantages include that no entry sorting is needed, lookup speed is high, entry updating is completed fast with pipelining, and lookup continuity is enhanced. It satisfies wire-speed (48B-packet) forwarding of OC-768 (40Gbps) interfaces of IPv4/IPv6 dual-stack core routers.