Chapter 30 - Network Infrastructure

Abstract

This chapter describes three phases involved in the development of network infrastructure, based on examples from the evolution of the Internet. The Internet is currently in its second phase of evolution and appears to be entering its third. The first phase was characterized by the origin and development of the Internet as a ubiquitous infrastructure. During this period, its growth was governed largely by researchers and driven by e-mail and file transfer applications. The second phase of the Internet is characterized by ubiquity within the research community and by growth into the general population, driven by distributed hypermedia (the Web). The third phase may be characterized by ubiquity within the general population, driven by services beyond that of data transfer and access. Each phase is characterized by the technological capabilities available including network technologies, protocols, and services. In the past, the Internet proved the concept of packet switching, based on the assumption that computing costs drop more rapidly than communication link costs, such that sharing a link by multiplexing packets is more effective than providing new links. The result was a single model that enabled global ubiquity. With these principles having evolved, the current Internet now focuses on performance rather than only on simplicity.