Historical Perspective

During the past 10 years, the Internet has become a vital component of international commerce, interpersonal communication, and technological development. Network measurement is critical to this new communication medium’s continued viability. Researchers, service providers, and other members of the Internet community need to understand the Internet’s growth characteristics and the limitations affecting the system, both globally and locally. Network measurement was neglected in the Internet’s early stages, taking lower priority to increasing the network’s speed, capacity, and coverage. Recently, however, interest in network measurement has expanded, paving the way toward a growing understanding of the Internet’s structure and behavior. Unfortunately, as the number of Internet users has grown, antisocial and even malicious behavior has also increased. Countering these and other scaling challenges will require substantially more investment in Internet measurement and data analysis. The four articles that follow provide an introduction to this vital research area. Historical Perspective In its early history, before 1995, the Internet primarily served a worldwide research community. The infrastructure that seeded the Internet was funded by US government agencies (DARPA and the National Science Foundation), which supported regional networks operated by organizations around the country. Merit Network (www.merit.edu), which operated the NSFnet backbone in its various forms, measured the backbone’s traffic volumes and produced summary statistics through April 1995. (See www.cc.gatech.edu/gvu/stats/NSF/merit. html.) But these were primarily oriented toward short-term operational requirements or periodic simplistic traffic reports for funding agencies. As such, they weren’t conducive to workload or performance characterization, much less network-dynamics modeling. As the NSFnet and attached regional infrastructures exploded in popularity among academic and commercial sectors, operators acutely focused on increasing link speeds and router/switch-traffic capacities, as well as expanding the topology to cover