FYI on "What is the Internet?"
RFC 1462

Document Type RFC - Informational (May 1993; No errata)
Also known as FYI 20
Last updated 2013-03-02
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Network Working Group                                          E. Krol
Request for Comments: 1462                      University of Illinois
FYI: 20                                                     E. Hoffman
                                                   Merit Network, Inc.
                                                              May 1993

                     FYI on "What is the Internet?"

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard.  Distribution of this memo is


   This FYI RFC answers the question, "What is the Internet?" and is
   produced by the User Services Working Group of the Internet
   Engineering Task Force (IETF). Containing a modified chapter from Ed
   Krol's 1992 book, "The Whole Internet User's Guide and Catalog," the
   paper covers the Internet's definition, history, administration,
   protocols, financing, and current issues such as growth,
   commercialization, and privatization.


   A commonly asked question is "What is the Internet?" The reason such
   a question gets asked so often is because there's no agreed upon
   answer that neatly sums up the Internet. The Internet can be thought
   about in relation to its common protocols, as a physical collection
   of routers and circuits, as a set of shared resources, or even as an
   attitude about interconnecting and intercommunication. Some common
   definitions given in the past include:

      * a network of networks based on the TCP/IP protocols,
      * a community of people who use and develop those networks,
      * a collection of resources that can be reached from those

   Today's Internet is a global resource connecting millions of users
   that began as an experiment over 20 years ago by the U.S.  Department
   of Defense. While the networks that make up the Internet are based on
   a standard set of protocols (a mutually agreed upon method of
   communication between parties), the Internet also has gateways to
   networks and services that are based on other protocols.

Krol & Hoffman                                                  [Page 1]
RFC 1462                 What is the Internet?                  May 1993

   To help answer the question more completely, the rest of this paper
   contains an updated second chapter from "The Whole Internet User's
   Guide and Catalog" by Ed Krol (1992) that gives a more thorough
   explanation. (The excerpt is published through the gracious
   permission of the publisher, O'Reilly & Associates, Inc.)

The Internet (excerpt from "The Whole Internet User's Guide and

   The Internet was born about 20 years ago, trying to connect together
   a U.S. Defense Department network called the ARPAnet and various
   other radio and satellite networks. The ARPAnet was an experimental
   network designed to support military research--in particular,
   research about how to build networks that could withstand partial
   outages (like bomb attacks) and still function.  (Think about this
   when I describe how the network works; it may give you some insight
   into the design of the Internet.) In the ARPAnet model, communication
   always occurs between a source and a destination computer. The
   network itself is assumed to be unreliable; any portion of the
   network could disappear at any moment (pick your favorite
   catastrophe--these days backhoes cutting cables are more of a threat
   than bombs). It was designed to require the minimum of information
   from the computer clients. To send a message on the network, a
   computer only had to put its data in an envelope, called an Internet
   Protocol (IP) packet, and "address" the packets correctly. The
   communicating computers--not the network itself--were also given the
   responsibility to ensure that the communication was accomplished. The
   philosophy was that every computer on the network could talk, as a
   peer, with any other computer.

   These decisions may sound odd, like the assumption of an "unreliable"
   network, but history has proven that most of them were reasonably
   correct. Although the Organization for International Standardization
   (ISO) was spending years designing the ultimate standard for computer
   networking, people could not wait. Internet developers in the US, UK
   and Scandinavia, responding to market pressures, began to put their
   IP software on every conceivable type of computer. It became the only
   practical method for computers from different manufacturers to
   communicate. This was attractive to the government and universities,
   which didn't have policies saying that all computers must be bought
   from the same vendor. Everyone bought whichever computer they liked,
   and expected the computers to work together over the network.

   At about the same time as the Internet was coming into being,
   Ethernet local area networks ("LANs") were developed. This technology
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