Overview

As we enter the new millennium, we are seeing dramatic changes in the telecommunications industry that have far-reaching implications for our lifestyles. There are many drivers for these changes. First and foremost is the continuing, relentless need for more capacity in the network. This demand is fueled by many factors. The tremendous growth of the Internet and the World Wide Web, both in terms of number of users as well as the amount of time and thus bandwidth taken by each user, is a major factor. A simple example of the latter phenomenon is the following: An average voice phone call lasts about 3 minutes; in contrast, users connecting to the Internet via dialup lines typically stay on for an average of 20 minutes. So an Internet call brings in about six times as much traffic into a network as a voice call.

Internet traffic has been doubling every four to six months, and this trend appears set to continue for a while. Meanwhile we are seeing the ongoing deployment of broadband access technologies such as digital subscriber line (DSL) and cable modems, which provide bandwidths per user on the order of 1 Mb/s, contrasted against the 28-56 kb/s available over dialup lines. The impact of such deployments is quite significant. A 10% increase in penetration of DSL among the 100 million total U.S. households will bring in another 1 Tb/s of traffic into the network, assuming that 10% of these users are on simultaneously.

At the same time,...