ing IP addresses. This system of addresses and names linked by name servers establishes the signposts in cyberspace and serves as the basic infrastructure supporting navigation across the Internet. It is called the Domain Name System (DNS).
This report is concerned with the Domain Name System and its interactions with Internet navigation, including its uses as a means of navigation itself and as an infrastructure for navigation by other means. Since the World Wide Web is the application running on the Internet that contains the greatest number of locations to which most users want to navigate, this report often draws examples from the Web. However, there are other applications that use the Internet, not least e-mail, and others that are being developed for it. The DNS supports most of them. Unless otherwise specified, the information in this report, its conclusions, and its recommendations apply to the DNS in its role as a basic infrastructure element of the entire Internet, not just of the World Wide Web.
The report’s specific objectives and how it is organized to address them are spelled out in this chapter, which begins with an introduction to the Internet, the Domain Name System, and Internet navigation, and with an examination of the forces affecting them. Four basic concepts that are used throughout this report—names, navigation, technical system, and institutional framework—are defined and briefly described in Box 1.1.
The Internet, according to the National Research Council, is “a diverse set of independent networks, interlinked to provide its users with the appearance of a single, uniform network…. The networks that compose the Internet share a common architecture (how the components of the networks interrelate) and software protocols (standards governing the interchange of data) that enable communication within and among the constituent networks.”1
Internally, the Internet comprises two types of elements: communication links, channels over which data travel from point to point; and routers, computers at the network’s nodes that direct data arriving along incoming links to outgoing links that will take them toward their destinations. Altogether, the Internet is a complex network of routers and links, the latter varying in transmission medium (telephone lines, cable lines, optical fiber cable, satellite, wireless); servers and other hosts; and access equipment. Links in the network may be characterized by their transmission capacity (low-capacity local lines