SUSE: superior storage-efficiency for routing tables through prefix transformation and aggregation

Abstract--A novel storage design for IP routing table construction is introduced on the basis of a single set-associative hash table to support fast longest prefix matching (LPM). The proposed design involves two key techniques to lower table storage required drastically: 1) storing transformed prefix representations; and 2) accommodating multiple prefixes per table entry via prefix aggregation, achieving superior storage-efficiency (SUSE). With each prefix (p(x)) maneuvered as a polynomial, p(x) = q(x) 2 g(x) + r(x) based on a divisor g(x), SUSE keeps only q(x) rather than full and long p(x) in an r(x)-indexed table with 2 degree(g(x)) entries, because q(x) and r(x) uniquely identify p(x). Additionally, using r(x) as the hash index exhibits better distribution than do original prefixes, reducing hash collisions, which can be tolerated further by the set-associative design. Given a set of chosen prefix lengths (called "treads"), all prefixes are rounded down to nearest treads...

• Type: Journal
• Year: 2010
• Where: TON
• Authors: Fong Pong, Nian-Feng Tzeng
• Keywords: Prefix Aggregation, Routing Table, SUSE, TON 2010