RFC 1462 (rfc1462) - Page 2 of 11

FYI on "What is the Internet?"

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
Catalog")

   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
   matured quietly, until desktop workstations became available around
   1983. Most of these workstations came with Berkeley UNIX, which
   included IP networking software. This created a new demand: rather



Krol & Hoffman