Route Table Partitioning and Load Balancing for Parallel Searching with TCAMs

Abstract

With the continuous advances in optical communications technology, the link transmission speed of Internet backbone has been increasing rapidly. This in turn demands more powerful IP address lookup engine. In this paper, we propose a power-efficient parallel TCAM-based lookup engine with a distributed logical caching scheme for dynamic load-balancing. In order to distribute the lookup requests among multiple TCAM chips, a smart partitioning approach called pre-order splitting divides the route table into multiple sub-tables for parallel processing. Meanwhile, by virtual of the cache-based load balancing scheme with slow-update mechanism, a speedup factor ofN-1 can be guaranteed for a system with N (N>2) TCAM chips, even with unbalanced bursty lookup requests.