Internet Growth: Is There a “Moore’s Law” for Data Traffic?

Abstract

Internet traffic is approximately doubling each year. This growth rate applies not only to the entire Internet, but to a large range of individual institutions. For a few places we have records going back several years that exhibit this regular rate of growth. Even when there are no obvious bottlenecks, traffic tends not to grow much faster. This reflects complicated interactions of technology, economics, and sociology, similar to, but more delicate than those that have produced “Moore’s Law” in semiconductors.

A doubling of traffic each year represents extremely fast growth, much faster than the increases in other communication services. If it continues, data traffic will surpass voice traffic around the year 2002. However, this rate of growth is slower than the frequently heard claims of a doubling of traffic every three or four months. Such spectacular growth rates apparently did prevail over a two-year period 1995–6. Ever since, though, growth appears to have reverted to the Internet’s historical pattern of a single doubling each year.

Progress in transmission technology appears sufficient to double network capacity each year for about the next decade. However, traffic growth faster than a tripling each year could probably not be sustained for more than a few years. Since computing and storage capacities will also be growing, as predicted by the versions of “Moore’s Law” appropriate for those technologies, we can expect demand for data transmission to continue increasing. A doubling in Internet traffic each year appears a likely outcome.

If Internet traffic continues to double each year, we will have yet another form of “Moore’s Law.” Such a growth rate would have several important implications. In the intermediate run, there would be neither a clear “bandwidth glut” nor a “bandwidth scarcity,” but a more balanced situation, with supply and demand growing at comparable rates. Also, computer and network architectures would be strongly affected, since most data would stay local. Programs such as Napster would play an increasingly important role. Transmission would likely continue to be dominated by file transfers, not by real time streaming media.