Internet

A map graphically displaying interconnections on the Internet (known as routes)

The Internet is a "network of networks" best known as the global network the World Wide Web is run on. It is common to call the World Wide Web "the Internet" but this is not accurate. The Web is the Internet's best known and front-facing service; however there are literally hundreds of different protocols, applications and services that run over the Internet.

The first functional networks between individual computers were created in the early 1970s. These networks, however, assumed the computers ran common software and protocols. Some of the networks were proprietary to computer vendors, such as IBM's Binary Synchronous Communications and the 1974 System Network Architecture, Xerox Network Services, Digital Equipment Corporation DECnet. X.25 was a nonproprietary standard, but used a different architecture than would the datagram networks such as the ARPANET and Internet.

Louis Pozin first introduced the idea of a generalized method of interconnecting networks of computers rather than individual computers, which he termed a catenet, but the model needed refinement. Such refinement took place under the sponsorship of the United States Department of Defense's Advanced Research Project Agency (ARPA), later renamed the Defense Advanced Research Projects Agency (DARPA). ARPA was formed to meet a number of perceived Cold War technology challenges, and was established in 1958 as the first U.S. response to the Soviet launching of Sputnik.

Among ARPA's areas of interest was the interconnection of networks, under the management and inspiration of J.C.R. Licklider 1915-1990, one of the pioneers of cooperative research. Vint Cerf extended Pouzin's catenet model as the basis for what was to become the ARPANET:

The U.S.

DARPA research project on this subject has adopted the term to mean roughly "the collection of packet networks which are connected together." This is, however, not a sufficiently explicit definition to determine, for instance, whether a new network is in conformance with the rules for network interconnection which make the catenet function as confederation

of co-operating networks.

Cerf extended the concept of catenet to be usable in a specific research network, the ARPANET. ARPANET was the first large-scale "network of networks" using common mechanisms to interconnect disparate networks. It was funded through ARPA, and access was limited to selected universities, research organizations, and government agencies. Contrary to widespread legend, it was never intended to be a military network survivable under nuclear attack, although other, not necessarily packet-switching, networks, were intended for warfighting. starting as early as the 1963 SACCS, specific to the Strategic Air Command. Other warfighting networks included the even earlier Minimum Essential Emergency Command Network (MEECN), which was made up of multiple networks that were interconnected only through human intervention. Even today, the military warfighting networks, such as NIPRNET, SIPRNET, JWICS and Warfighter Information Network are separate from the Internet.

Many educational institutions and corporations began joining the network, and in 1983 all nodes on the ARPANET changed over at once to Internet Protocol version 4 (IPv4), which is still in use on the internet today. While this is often called "TCP/IP", those are two distinct protocols: Transmission Control Protocol (TCP), and IPv4.

There were several intermediate steps between the ARPANET, to which access was strictly controlled, and today's ubiquitous Internet. See History

While IPv4 will be present indefinitely, it is limited in its capability for modern functions, and an evolution is in process to Internet Protocol version 6 (IPv6). Internally, the Internet is divided into Autonomous Systems, which exchange information about the destinations they can reach, using the Border Gateway Protocol (BGP).

History

1950s to 1970s

• DARPA
• BBN - Bolt, Barenek and Newman
• NCP

1975 to 1980

• Email was invented, then shortly thereafter Spam was invented. Ugh.