PCAM-based wire-speed range matching in multidimensional packet classification

Building large high-speed multi-field packet classifiers is an acknowledged challenge to researchers. PC rules specify ranges, IP prefixes or wildcards. Current PCs inefficiently search a range as multiple prefixes. The present paper proposes generalized hardware-specific wire-speed direct search of ranges and wildcards. Associative search tables, created through preprocessing of the rule database, are searched using RAM-based pipelined CAMs (PCAM) which are likely to provide a better alternative to TCAMs. The proposed range-based search engine has constant search time, irrespective of rule database sizes and field value widths.