NSFNET

NSFNET, the National Science Foundation Network, was a program launched in 1985 to build a national high-speed network connecting the NSF-sponsored supercomputing centers and major universities. It operated as the backbone of the United States research Internet during the late 1980s and early 1990s, providing the primary routing infrastructure for academic and government researchers and helping extend Internet connectivity beyond its earlier ARPANET roots.

The backbone linked regional networks and campuses through leased telecommunications lines. It began with relatively modest speeds, typically 1.5 megabits per second (T1), and was expanded over the next several years to higher capacities (notably 45 Mbps, a T3 link) to accommodate growth in traffic and institutions. The NSF funded the backbone and contracted operation to Merit Network and partner networks, which managed network routing and coordination among sites.

During the early 1990s, NSFNET traffic surged as more national and international research networks connected. In 1990, ARPANET—the predecessor to the Internet—was formally decommissioned, leaving NSFNET as the principal backbone for research networks in the United States. In the mid-1990s, policy and market developments encouraged commercial providers to assume backbone roles, and the NSFNET backbone was gradually phased out and retired in 1995.

Legacy: The NSFNET program is widely seen as instrumental in the evolution of the Internet. It demonstrated scalable, open interconnection among diverse networks and helped catalyze the transition to a commercially operated Internet, while preserving a period of rapid growth in networking research and education.