Forwarding Engine for IPv6

Abstract

We focus on forwarding engine for million entry IPv6 (Internet Protocol version 6) routing tables. The memory requirements are analyzed for a trie based scheme and a binary search scheme for doing IP address lookup. We also develop an architecture to bound the worst-case update performance of lookup schemes.

The scalability of the two lookup schemes was analyzed with respect to increasing routing table size and increase in address size. Currently available DRAM memories were analyzed for memory access requirements and memory mapping schemes were developed to improve the lookup performance. The trie based scheme was analyzed with respect to variations in different parameters like depth, pipeline stages, etc.

The update performance of IP lookup schemes was identified as a potential problem and an architecture was developed to bound the worst-case performance. The update mechanism is independent of the lookup scheme and is implemented in hardware. The implementation is done in a 0.25u CMOS cell library.