Heuristic Binary Search: Adaptive and Fast IPv6 Route Lookup with Incremental Updates

Abstract

The advent of Software Defined Networking (SDN) and Network Function Virtualization (NFV) has revolutionized the deployment of software-based routing and forwarding devices in modern network architectures. However, IPv6 route lookup remains a substantial performance bottleneck in these software-based devices due to two key challenges: (1) the longer addresses and prefixes, which hinder high-speed IPv6 lookup, and (2) the larger address space of IPv6 necessitates adaptability to varied length-based prefix distributions across various network scenarios. Current trie-based methods like SAIL and Poptrie have enhanced IPv4 lookup, but they struggle with adaptive and fast IPv6 lookup due to their fixed search scheme from short to long prefixes. To overcome these challenges, we propose a novel Heuristic Binary Search (HBS) scheme to achieve adaptive and fast IPv6 lookup. HBS refines the traditional "Binary Search on Prefix Lengths" scheme by incorporating two key techniques: (1) a heuristic binary search method for accelerated lookup and (2) a tree rotation method for dynamic adjustment of binary search tree shapes in response to changes in prefix distribution. Our evaluation of HBS demonstrates its superiority in terms of lookup throughput, update speed, memory efficiency, and dynamic adaptability.