Segregating the encompassing prefixes to enhance the performance of packet forwarding engines
M.J. Akhbarizadeh, Mehrdad Nourani, Cyrus D. Cantrell · 2005
We propose a novel approach for IP packet forwarding based on a new ternary content addressable memory configuration. Our design is an efficient hardware solution for the longest prefix matching problem in Internet routers. Our scheme segregates the encompassing prefixes into a separate, practically small TCAM module. Consequently, the remaining prefixes, that often conform to more than 92% of the lookup table, form a disjoint set. The big TCAM module that accommodates this set has a simplified architecture, with no priority encoder. Our architecture has lower update complexity, lower cost and shorter search time, compared to the conventional TCAM structure.