A Brief History of the Internet and
Related Networks
Introduction
In 1973, the U.S. Defense Advanced Research Projects
Agency (DARPA) initiated a research program to investigate techniques and
technologies for interlinking packet networks of various kinds. The objective
was to develop communication protocols which would allow networked computers
to communicate transparently across multiple, linked packet networks. This
was called the Internetting project and the system of networks which emerged
from the research was known as the "Internet." The system of protocols
which was developed over the course of this research effort became known
as the TCP/IP Protocol Suite, after the two initial protocols developed:
Transmission Control Protocol (TCP) and Internet Protocol (IP).
In 1986, the U.S. National Science Foundation
(NSF) initiated the development of the NSFNET which, today, provides a
major backbone communication service for the Internet. With its 45 megabit
per second facilities, the NSFNET carries on the order of 12 billion packets
per month between the networks it links. The National Aeronautics and Space
Administration (NASA) and the U.S. Department of Energy contributed additional
backbone facilities in the form of the NSINET and ESNET respectively. In
Europe, major international backbones such as NORDUNET and others provide
connectivity to over one hundred thousand computers on a large number of
networks. Commercial network providers in the U.S. and Europe are beginning
to offer Internet backbone and access support on a competitive basis to
any interested parties.
"Regional" support for the Internet is provided
by various consortium networks and "local" support is provided through
each of the research and educational institutions. Within the United States,
much of this support has come from the federal and state governments, but
a considerable contribution has been made by industry. In Europe and elsewhere,
support arises from cooperative international efforts and through national
research organizations. During the course of its evolution, particularly
after 1989, the Internet system began to integrate support for other protocol
suites into its basic networking fabric. The present emphasis in the system
is on multiprotocol interworking, and in particular, with the integration
of the Open Systems Interconnection (OSI) protocols into the architecture.
Both public domain and commercial implementations
of the roughly 100 protocols of TCP/IP protocol suite became available
in the 1980's. During the early 1990's, OSI protocol implementations also
became available and, by the end of 1991, the Internet has grown to include
some 5,000 networks in over three dozen countries, serving over 700,000
host computers used by over 4,000,000 people.
A great deal of support for the Internet community
has come from the U.S. Federal Government, since the Internet was originally
part of a federally-funded research program and, subsequently, has become
a major part of the U.S. research infrastructure. During the late 1980's,
however, the population of Internet users and network constituents expanded
internationally and began to include commercial facilities. Indeed, the
bulk of the system today is made up of private networking facilities in
educational and research institutions, businesses and in government organizations
across the globe.
The Coordinating Committee for Intercontinental
Networks (CCIRN), which was organized by the U.S. Federal Networking Council
(FNC) and the European Reseaux Associees pour la Recherche Europeenne (RARE),
plays an important role in the coordination of plans for government- sponsored
research networking. CCIRN efforts have been a stimulus for the support
of international cooperation in the Internet environment.
Internet Technical Evolution
Over its fifteen year history, the Internet has functioned
as a collaboration among cooperating parties. Certain key functions have
been critical for its operation, not the least of which is the specification
of the protocols by which the components of the system operate. These were
originally developed in the DARPA research program mentioned above, but
in the last five or six years, this work has been undertaken on a wider
basis with support from Government agencies in many countries, industry
and the academic community. The Internet Activities Board (IAB) was created
in 1983 to guide the evolution of the TCP/IP Protocol Suite and to provide
research advice to the Internet community.
During the course of its existence, the IAB has
reorganized several times. It now has two primary components: the Internet
Engineering Task Force and the Internet Research Task Force. The former
has primary responsibility for further evolution of the TCP/IP protocol
suite, its standardization with the concurrence of the IAB, and the integration
of other protocols into Internet operation (e.g. the Open Systems Interconnection
protocols). The Internet Research Task Force continues to organize and
explore advanced concepts in networking under the guidance of the Internet
Activities Board and with support from various government agencies.
A secretariat has been created to manage the day-to-day
function of the Internet Activities Board and Internet Engineering Task
Force. IETF meets three times a year in plenary and its approximately 50
working groups convene at intermediate times by electronic mail, teleconferencing
and at face-to-face meetings. The IAB meets quarterly face-to-face or by
videoconference and at intervening times by telephone, electronic mail
and computer-mediated conferences.
Two other functions are critical to IAB operation:
publication of documents describing the Internet and the assignment and
recording of various identifiers needed for protocol operation. Throughout
the development of the Internet, its protocols and other aspects of its
operation have been documented first in a series of documents called Internet
Experiment Notes and, later, in a series of documents called Requests for
Comment (RFCs). The latter were used initially to document the protocols
of the first packet switching network developed by DARPA, the ARPANET,
beginning in 1969, and have become the principal archive of information
about the Internet. At present, the publication function is provided by
an RFC editor.
The recording of identifiers is provided by the
Internet Assigned Numbers Authority (IANA) who has delegated one part of
this responsibility to an Internet Registry which acts as a central repository
for Internet information and which provides central allocation of network
and autonomous system identifiers, in some cases to subsidiary registries
located in various countries. The Internet Registry (IR) also provides
central maintenance of the Domain Name System (DNS) root database which
points to subsidiary distributed DNS servers replicated throughout the
Internet. The DNS distributed database is used, inter alia, to associate
host and network names with their Internet addresses and is critical to
the operation of the higher level TCP/IP protocols including electronic
mail.
There are a number of Network Information Centers
(NICs) located throughout the Internet to serve its users with documentation,
guidance, advice and assistance. As the Internet continues to grow internationally,
the need for high quality NIC functions increases. Although the initial
community of users of the Internet were drawn from the ranks of computer
science and engineering, its users now comprise a wide range of disciplines
in the sciences, arts, letters, business, military and government administration.
Related Networks
In 1980-81, two other networking projects, BITNET
and CSNET, were initiated. BITNET adopted the IBM RSCS protocol suite and
featured direct leased line connections between participating sites. Most
of the original BITNET connections linked IBM mainframes in university
data centers. This rapidly changed as protocol implementations became available
for other machines. From the beginning, BITNET has been multi-disciplinary
in nature with users in all academic areas. It has also provided a number
of unique services to its users (e.g., LISTSERV). Today, BITNET and its
parallel networks in other parts of the world (e.g., EARN in Europe) have
several thousand participating sites. In recent years, BITNET has established
a backbone which uses the TCP/IP protocols with RSCS-based applications
running above TCP.
CSNET was initially funded by the National Science
Foundation (NSF) to provide networking for university, industry and government
computer science research groups. CSNET used the Phonenet MMDF protocol
for telephone-based electronic mail relaying and, in addition, pioneered
the first use of TCP/IP over X.25 using commercial public data networks.
The CSNET name server provided an early example of a white pages directory
service and this software is still in use at numerous sites. At its peak,
CSNET had approximately 200 participating sites and international connections
to approximately fifteen countries.
In 1987, BITNET and CSNET merged to form the Corporation
for Research and Educational Networking (CREN). In the Fall of 1991, CSNET
service was discontinued having fulfilled its important early role in the
provision of academic networking service. A key feature of CREN is that
its operational costs are fully met through dues paid by its member organizations.
