On the design of IP routers Part 1: Router architectures

Internet Protocol (IP) networks are currently undergoing transitions that mandate greater bandwidths and the need to prepare the network infrastructures for converged traffic (voice, video, and data). Thus, in the emerging environment of high performance IP networks, it is expected that local and campus area backbones, enterprise networks, and Internet Service Providers (ISPs) will use multigigabit and terabit networking technologies where IP routers will be used not only to interconnect backbone segments but also to act as points of attachments to high performance wide area links. Special attention must be given to new powerful architectures for routers in order to play that demanding role. In this paper, we describe the evolution of IP router architectures and highlight some of the performance issues affecting IP routers. We identify important trends in router design and outline some design issues facing the next generation of routers. It is also observed that the achievement of high throughput IP routers is possible if the critical tasks are identified and special purpose modules are properly tailored to perform them.