The Internet was designed to survive a nuclear war. But can it withstand the perils created by its own rapid growth?

At first glance, it’s hard to imagine that the Internet—in its current form, at least—could possibly be endangered. Total users are increasing at 120 percent per year. World Wide Web hosts are growing at 100 percent per year. Total spending on Internet products and services is rising at 110 percent per year. And the critical mass of users finally in place is attracting businesses that are making real commercial transactions—and consumers who are joining fledgling electronic communities.

Behind the scenes, however, the huge growth in demand from users shifting to ever more complicated applications, combined with rapid innovation, incomplete standards, fragmented competition, and unrealistic pricing policies, is producing an environment of wrenching and unpredictable change—one with which existing network service architectures are less and less able to cope. As users begin to flee increasingly degraded Internet performance in search of more specialized services, the many networks that make up the Internet are drifting further and further apart.

This balkanization of the Internet into multiple interconnected network families, each with a distinct user community and differentiated capabilities, means that...