Network Routing Evolution

In this paper we briefly examine some directions for evolution of routing in traffic networks of the future. General trends identified are the expected growth in ability to shift bandwidth both logically and physically. We identify four distinct stages in this evolution. The first stage we describe is the hierarchy that was the basis of virtually all networks just a few years ago. The next level of freedom, found in dynamic routing, allows logical shifts in routing to reallocate network bandwidth on, say, an hourly basis, or more rapidly, on a call-by-call basis. The third level we describe is robust routing for integrated networks, and this network implementation allows logical routing to shift network bandwidth rapidly among node pairs and services. Finally we describe integrated traffic/facility routing in which both physical and logical bandwidth are shifted in response to changing customer and network requirements.