In 1985, the NSF began funding the creation of five new supercomputer centers: the John von Neumann Center at Princeton University, the San Diego Supercomputer Center on the campus of the University of California at San Diego, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Cornell Theory Center at Cornell University and the Pittsburgh Supercomputing Center. The NSFNET connected these five centers and allowed access to their supercomputers over the network at no cost.
The NSFNET went online in 1986, using a TCP/IP-based protocol that was compatible with ARPANET, as a backbone to which regional and academic networks would connect. It experienced exponential growth in its network traffic. As a result of a November 1987 NSF award to a consortium of universities in Michigan, the original 56- kbit/s links were upgraded to 1.5 Mbit/s by July 1988 and again to 45 Mbit/s in 1991.
The NSFNET was the principal Internet backbone starting in approximately 1988, bridging between the rather restrictive US DoD creation of the Internet, and its broad commercialization in the mid-1990s. Basically, the NSFNET opened up the Internet to the world. Some critical Internet technologies, such as the Border Gateway Protocol (BGP) are a direct result of that period in Internet history. BGP was specifically created to allow the NSFNET backbone to differentiate routes learned via multiple paths from originally the Arpanet, but also from the regional networks. This then turned the Internet into a meshed infrastructure, backing away from the single-core architecture which the Arpanet had been using before.
The original 56-kb/s backbone was overseen by the supercomputer centers themselves with the lead taken by Ed Krol at the University of Illinois at Urbana-Champaign. PDP-11/73 Fuzzball routers were configured and run by Hans-Werner Braun at the University of Michigan and statistics collected by Cornell University.
From 1987 to 1995 the NSFNET Backbone was designed, managed, and operated on behalf of the NSF by Merit Network, Inc., a non-profit corporation governed by public Universities, with Eric M. Aupperle being the Project Director, and Hans-Werner Braun Principal Investigator. IBM, MCI, and the State of Michigan were additional project partners.
On April 30, 1995, the NSFNET Backbone Service was successfully transitioned to a new architecture, where traffic is exchanged at interconnection points called Network access points.