Hardware-based IP lookup using n-way set associative memory and LPM comparator

IP lookup process becomes the bottleneck of packet transmission as IP traffic increases. Hardware-based IP lookup is desirable for high-speed router. However, the IP lookup schemes using an index-based table are not efficient due to heavy prefix expansion. In this paper, efficient hardware-based IP lookup schemes using n-way set associative memory and a LPM comparator is proposed. It reduces memory requirements to about 50% or below compared with previous scheme and provides faster updating speed. It also completes an IP routing lookup with two memory accesses.