NSFNET and MERIT

The National Science Foundation Network

The National Science Foundation (NSF) was established in 1950 to promote scientific research and education. NSF's support for computer networking began with the 1985 announcement of funding for National Advanced Scientific Computing Centers, which connected universities to supercomputers at five locations: Cornell, University of Illinois, Carnegie Mellon/University of Pittsburgh, UC San Diego, and Princeton.

NSFNET Backbone Evolution

NSFNET Acceptable Use Policy (AUP)

The NSFNET AUP restricted commercial use, defining the boundary between the research internet and the commercial internet:

• No use for "for-profit" activities
• No access to "problem-oriented" recreational games
• Research and educational use only
• NSF funding could not subsidize commercial traffic

The AUP created tension as the internet grew beyond research into commerce. When NSFNET was decommissioned in 1995, commercial ISPs were large enough to take over backbone operations, ending the research-only era.

MERIT Network Inc.

MERIT (Michigan Educational Research Information Triad) was founded in 1966 by Michigan State University, the University of Michigan, and Wayne State University. Eric Aupperle was hired as senior engineer in 1969. The organization sought non-state funds for interuniversity computer communications — a novel concept at the time.

Key Milestones

• 1971: Successfully networked mainframe computers at MSU, U-M, WSU
• 1978: Western Michigan University joins as fourth member
• 1987: Wins $39.8 million NSFNET Cooperative Agreement with IBM and MCI
• 1990: ANS (Advanced Networks & Services) formed from Merit/IBM/MCI merger
• 1996: Becomes Internet2 affiliate member

ANS Formation and Commercial Split

In 1990, Merit, IBM, and MCI merged their network operations to form ANS. This split into:

• ANS CO+RE: Commercial network services (later part of AOL, then Verizon)
• ANS Research: Research network operations (merged into Internet2)

This commercial/research split was pivotal in transitioning from NSFNET to the modern commercial internet.

Key Technical Milestones

TCP/IP Adoption: January 1, 1983 — "Flag Day"

ARPANET officially switched from NCP to TCP/IP on January 1, 1983. This established TCP/IP as the standard protocol suite for internetworking. Jon Postel (ISI/University of Southern California) authored RFC 791 (Internet Protocol) and RFC 793 (TCP) — the foundational documents of the modern internet.

CIDR Deployment (1993)

Classless Inter-Domain Routing (CIDR, RFC 1517–1519) solved the Class B address exhaustion crisis and routing table growth explosion:

• RFC 1517: Applicability Statement establishing CIDR as the solution
• RFC 1518: Address allocation architecture (Rekhter & Li)
• RFC 1519: Address assignment and aggregation strategy (Fuller, Li, Yu, Varadhan)

Routing table growth data (from MERIT, per RFC 1519):

• December 1988: 334 routes
• December 1989: 897 routes
• December 1990: 2,190 routes
• December 1991: 4,305 routes
• December 1992: 8,561 routes

Without CIDR, projections showed 75,000+ routes by 1995. CIDR deployment reduced growth to ~6% annually.

DNS Introduction (1984)

Paul Mockapetris developed the Domain Name System in 1984, replacing static host tables with a hierarchical, distributed naming system. DNS enabled human-readable addresses (e.g., txrx.tech) instead of IP addresses (e.g., 192.0.2.1).

Research and Regional Networks

Internet2

Founded in 1996, Internet2 is a not-for-profit computer network consortium providing a dedicated high-speed research network. Today operating at 100 Gbps with 9.6 Tbps capacity across its backbone, connecting over 400 universities, research institutions, and government agencies.

ESnet (Energy Sciences Network)

ESnet, operated by Lawrence Berkeley National Laboratory for the US Department of Energy, provides high-speed connectivity connecting scientific research facilities worldwide. ESnet 6 (projected completion 2023) features 100–400 Gbps capacity, with 400 Gbps links to major HPC centers.

CANARIE

Canada's national research and innovation network, operating CA*net 4 (100 Gbps) and supporting over 1,200 institutions. CANARIE pioneered national research networking in Canada from 1990 onward.

The Transition to Commercial Internet (1995)

On April 30, 1995, NSF let the NSFNET backbone contract expire. Commercial ISPs — including UUNET, PSINet, and others — had grown large enough to take over backbone operations. The research-only era of the internet officially ended. NSFNET's acceptable use policy restrictions dissolved. The internet became truly commercial.

This transition was not planned in advance — it emerged organically as commercial demand grew. NSFNET's original mission (connecting researchers) was absorbed into Internet2 and ESnet, while the public-facing internet commercialized and expanded to billions of users.