A Distributed TCAM Coprocessor Architecture for Integrated Longest Prefix Matching, Policy Filtering, and Content Filtering

Abstract

Longest Prefix Matching (LPM), Policy Filtering (PF), and Content Filtering (CF) are three important tasks for Internet nowadays. It is both technologically and economically important to develop integrated solutions to the effective execution of the three tasks. To this end, in this paper, we propose a distributed Ternary Content Addressable Memory (TCAM) coprocessor architecture. The integrated solution exploits the complementary lookup load and storage load requirements of the three tasks to balance the lookup load and storage load among the TCAMs. A prefix filtering-based CF algorithm is designed to reduce the lookup load and a novel cache system is developed to dynamically handle the lookups from overloaded TCAMs. Simulations based on real-world traffic traces show that the proposed solution can perform all three tasks given a 10 Gbps line rate using only the resources required to perform just the CF task given a 10 Gbps line rate.