NSFNET

The was a major part of early 1990s Internet backbone.

History
Following the deployment of the CSNET, a network that linked academic computer science departments, in 1981, the NSF aimed to create an open network allowing academic researchers access to supercomputers.

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 National Science Foundation Network (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-kilobit per second links were upgraded to 1.5 megabits per second by July 1988 and again to 45 megabits per second in 1991.

The NSFNET was the principal Internet backbone starting in approximately 1988, bridging between the rather restrictive U.S. 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.

Privatization
In the early 1990s, commercial organizations connecting to the Internet had to sign a usage agreement directly with NSFNET to gain access to large parts of the public Internet, regardless of what Internet service provider they purchased Internet access from.

The original 56-kilobits-per-second backbone was overseen by the supercomputer centers themselves with the lead taken by Ed Krol at the University of Illinois at Urbana-Champaign.

From 1987 to 1995 the NSFNET backbone was architected, managed, and operated on behalf of the NSF by Merit Network, Inc., a non-profit corporation governed by public Universities. 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 was exchanged at interconnection points called Network access points.

Controversy
For much of the period from 1987 to 1995 there was concern by some Internet stakeholders, following NSFNET's opening up the Internet, over the effects of privatization and the manner in which IBM and MCI were given a perceived competitive advantage in "leveraging" federal research money to gain ground in fields that other companies were allegedly more competitive in.