Tree-Combined Trie: A Compressed Data Structure for Fast IP Address Lookup

For meeting the requirements of the high-speed Internet and satisfying the Internet users, building fast routers with high-speed IP address lookup engine is inevitable. Regarding the unpredictable variations occurred in the forwarding information during the time and space, the IP lookup algorithm should be able to customize itself with temporal and spatial conditions. This paper proposes a new dynamic data structure for fast IP address lookup. This novel data structure is a dynamic mixture of trees and tries which is called Tree-Combined Trie or simply TC-Trie. Binary sorted trees are more advantageous than tries for representing a sparse population while multibit tries have better performance than trees when a population is dense. TC-trie combines advantages of binary sorted trees and multibit tries to achieve maximum compression of the forwarding information. Dynamic reconfiguration of TC-trie, made it capable of customizing itself along the time and scaling to support more prefixes or longer IPv6 prefixes. TC-trie provides a smooth transition from current large IPv4 databases to the large IPv6 databases of the future Internet.