To cope with the growth in the Internet and corporate IP networks we require IP routers capable of much higher performance than is possible with existing architectures. This paper examines two approaches to the design o f a h igh-performance router, the gigabit router and the IP switch, and then p rovides s ome detail on the implementation of an IP switch and the protocols associated with IP switching.

‡ The Internet is growing rapidly. The number of hosts on the Internet has doubled approximately every 56 weeks since 1989 (14) and the number of web servers has doubled at least every 23 weeks for the last three years (15). As such growth persists, and as common access line speeds increase, we require IP routing capacity of many gigabits/s (Gbps) of aggregate traffic. Existing bus and central processor based architectures can handle a maximum load in the region of 1 Gbps and a few hundred thousand packets per second (kpps) but to get much beyond this requires alternative architectures. This paper examines two such approaches, the gigabit router and the IP switch, and then provides some detail on the implementation of an IP switch and the protocols associated with IP switching.