Packet classification using a bloom filter in a leaf-pushing area-based quad-trie

Abstract

Packet classification is one of the most essential functions that Internet routers should perform at wire-speed for every incoming packet. An area-based quad-trie (AQT) for packet classification has an issue in search performance since many rule nodes can be encountered in a search procedure. A leaf-pushing AQT improves the search performance of the AQT by making a single rule node exist in each search path. This paper proposes a new algorithm to improve the search performance of the leaf-pushing AQT further. The proposed algorithm builds a leaf-pushing AQT using a Bloom filter and a hash table stored in on-chip memories. The level of a rule node and a pointer to a rule database are identified by sequentially querying the Bloom filter and by accessing the hash table, respectively.