Software Vault: The Diamond Collection/The Diamond Collection (Software Vault)(Digital Impact).ISO/cdr15/rfc1462.zip/INTERNET.INF

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Network Working Group                                         May 1993
Request for Comments: 1462                      University of Illinois
FYI: 20                                                     E. Hoffman
                                                   Merit Network, Inc.

                     "What is the Internet?"
Introduction

   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
        networks.

   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.

   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  [7mKrol [m (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 than connecting
   to a single large timesharing computer per site, organizations wanted
   to connect the ARPAnet to their entire local network. This would allow
   all the computers on that LAN to access ARPAnet facilities. About the
   same time, other organizations started building their own networks
   using the same communications protocols as the ARPAnet: namely, IP and
   its relatives. It became obvious that if these networks could talk
   together, users on one network could communicate with those on another;
   everyone would benefit.

   One of the most important of these newer networks was the NSFNET,
   commissioned by the National Science Foundation (NSF), an agency of the
   U.S. government. In the late 80's the NSF created five supercomputer
   centers. Up to this point, the world's fastest computers had only been
   available to weapons developers and a few researchers from very large
   corporations. By creating supercomputer centers, the NSF was making
   these resources available for any scholarly research. Only five centers
   were created because they were so expensive--so they had to be shared.
   This created a communications problem: they needed a way to connect
   their centers together and to allow the clients of these centers to
   access them.  At first, the NSF tried to use the ARPAnet for
   communications, but this strategy failed because of bureaucracy and
   staffing problems.

   In response, NSF decided to build its own network, based on the
   ARPAnet's IP technology. It connected the centers with 56,000 bit per
   second (56k bps) telephone lines.  (This is roughly the ability to
   transfer two full typewritten pages per second.  That's slow by modern
   standards, but was reasonably fast in the mid 80's.)  It was obvious,
   however, that if they tried to connect every university directly to a
   supercomputing center, they would go broke. You pay for these telephone
   lines by the mile. One line per campus with a supercomputing center at
   the hub, like spokes on a bike wheel, adds up to lots of miles of phone
   lines. Therefore, they decided to create regional networks. In each
   area of the country, schools would be connected to their nearest
   neighbor. Each chain was connected to a supercomputer center at one
   point and the centers were connected together. With this configuration,
   any computer could eventually communicate with any other by forwarding
   the conversation through its neighbors.

   This solution was successful--and, like any successful solution, a time
   came when it no longer worked. Sharing supercomputers also allowed the
   connected sites to share a lot of other things not related to the
   centers. Suddenly these schools had a world of data and collaborators
   at their fingertips. The network's traffic increased until, eventually,
   the computers controlling the network and the telephone lines
   connecting them were overloaded. In 1987, a contract to manage and
   upgrade the network was awarded to Merit Network Inc., which ran
   Michigan's educational network, in partnership with IBM and MCI. The
   old network was replaced with faster telephone lines (by a factor of
   20), with faster computers to control it.

   The process of running out of horsepower and getting bigger engines and
   better roads continues to this day. Unlike changes to the highway
   system, however, most of these changes aren't noticed by the people
   trying to use the Internet to do real work. You won't go to your
   office, log in to your computer, and find a message saying that the
   Internet will be inaccessible for the next six months because of
   improvements. Perhaps even more important: the process of running out
   of capacity and improving the network has created a technology that's
   extremely mature and practical. The ideas have been tested; problems
   have appeared, and problems have been solved.

   For our purposes, the most important aspect of the NSF's networking
   effort is that it allowed everyone to access the network. Up to that
   point, Internet access had been available only to researchers in
   computer science, government employees, and government contractors. The
   NSF promoted universal educational access by funding campus connections
   only if the campus had a plan to spread the access around. So everyone
   attending a four year college could become an Internet user.

   The demand keeps growing. Now that most four-year colleges are
   connected, people are trying to get secondary and primary schools
   connected. People who have graduated from college know what the
   Internet is good for, and talk their employers into connecting
   corporations. All this activity points to continued growth, networking
   problems to solve, evolving technologies, and job security for
   networkers.

What Makes Up the Internet?

   What comprises the Internet is a difficult question; the answer changes
   over time. Five years ago the answer would have been easy: "All the
   networks, using the IP protocol, which cooperate to form a seamless
   network for their collective users." This would include various federal
   networks, a set of regional networks, campus networks, and some foreign
   networks.

   More recently, some non-IP-based networks saw that the Internet was
   good. They wanted to provide its services to their clientele. So they
   developed methods of connecting these "strange" networks (e.g., Bitnet,
   DECnets, etc.) to the Internet. At first these connections, called
   "gateways", merely served to transfer electronic mail between the two
   networks. Some, however, have grown to translate other services between
   the networks as well. Are they part of the Internet? Maybe yes and
   maybe no. It depends on whether, in their hearts, they want to be. If
   this sounds strange, read on--it gets stranger.

Who Governs the Internet?

   In many ways the Internet is like a church: it has its council of
   elders, every member has an opinion about how things should work, and
   you can either take part or not. It's your choice. The Internet has no
   president, chief operating officer, or Pope. The constituent networks
   may have presidents and CEO's, but that's a different issue; there's no
   single authority figure for the Internet as a whole.

   The ultimate authority for where the Internet is going rests with the
   Internet Society, or ISOC. ISOC is a voluntary membership organization
   whose purpose is to promote global information exchange through
   Internet technology.  (If you'd like more information, or if you would
   like to join, contact information is provided in the "For More
   Information" section, near the end of this document.)  It appoints a
   council of elders, which has responsibility for the technical
   management and direction of the Internet.

   The council of elders is a group of invited volunteers called the
   Internet Architecture Board, or the IAB. The IAB meets regularly to
   "bless" standards and allocate resources, like addresses. The Internet
   works because there are standard ways for computers and software
   applications to talk to each other. This allows computers from
   different vendors to communicate without problems. It's not an IBM-only
   or Sun-only or Macintosh-only network. The IAB is responsible for these
   standards; it decides when a standard is necessary, and what the
   standard should be. When a standard is required, it considers the
   problem, adopts a standard, and announces it via the network. (You were
   expecting stone tablets?) The IAB also keeps track of various numbers
   (and other things) that must remain unique. For example, each computer
   on the Internet has a unique 32- bit address; no other computer has the
   same address.  How does this address get assigned? The IAB worries
   about these kinds of problems. It doesn't actually assign the
   addresses, but it makes the rules about how to assign addresses.

   As in a church, everyone has opinions about how things ought to run.
   Internet users express their opinions through meetings of the Internet
   Engineering Task Force (IETF). The IETF is another volunteer
   organization; it meets regularly to discuss operational and near-term
   technical problems of the Internet. When it considers a problem
   important enough to merit concern, the IETF sets up a "working group"
   for further investigation. (In practice, "important enough" usually
   means that there are enough people to volunteer for the working group.)
   Anyone can attend IETF meetings and be on working groups; the important
   thing is that they work. Working groups have many different functions,
   ranging from producing documentation, to deciding how networks should
   cooperate when problems occur, to changing the meaning of the bits in
   some kind of packet. A working group usually produces a report.
   Depending on the kind of recommendation, it could just be documentation
   and made available to anyone wanting it, it could be accepted
   voluntarily as a good idea which people follow, or it could be sent to
   the IAB to be declared a standard.

   If you go to a church and accept its teachings and philosophy, you are
   accepted by it, and receive the benefits. If you don't like it, you can
   leave. The church is still there, and you get none of the benefits.
   Such is the Internet. If a network accepts the teachings of the
   Internet, is connected to it, and considers itself part of it, then it
   is part of the Internet. It will find things it doesn't like and can
   address those concerns through the IETF. Some concerns may be
   considered valid and the Internet may change accordingly.  Some of the
   changes may run counter to the religion, and be rejected. If the
   network does something that causes damage to the Internet, it could be
   excommunicated until it mends its evil ways.

Who Pays for It?

   The old rule for when things are confusing is "follow the money." Well,
   this won't help you to understand the Internet. No one pays for "it";
   there is no Internet, Inc. that collects fees from all Internet
   networks or users. Instead, everyone pays for their part.  The NSF pays
   for NSFNET. NASA pays for the NASA Science Internet.  Networks get
   together and decide how to connect themselves together and fund these
   interconnections. A college or corporation pays for their connection to
   some regional network, which in turn pays a national provider for its
   access.

What Does This Mean for Me?

   The concept that the Internet is not a network, but a collection of
   networks, means little to the end user. You want to do something
   useful: run a program, or access some unique data. You shouldn't have
   to worry about how it's all stuck together. Consider the telephone
   system--it's an internet, too. Pacific Bell, AT&T, MCI, British
   Telephony, Telefonos de Mexico, and so on, are all separate
   corporations that run pieces of the telephone system. They worry about
   how to make it all work together; all you have to do is dial.

   If you ignore cost and commercials, you shouldn't care if you are
   dealing with MCI, AT&T, or Sprint. Dial the number and it works. You
   only care who carries your calls when a problem occurs. If something
   goes out of service, only one of those companies can fix it. They talk
   to each other about problems, but each phone carrier is responsible for
   fixing problems on its own part of the system.  The same is true on the
   Internet. Each network has its own network operations center (NOC). The
   operation centers talk to each other and know how to resolve problems.
   Your site has a contract with one of the Internet's constituent
   networks, and its job is to keep your site happy. So if something goes
   wrong, they are the ones to gripe at. If it's not their problem,
   they'll pass it along.

What Does the Future Hold?

   Finally, a question I can answer. It's not that I have a crystal ball
   (if I did I'd spend my time on Wall Street instead of writing a book).
   Rather, these are the things that the IAB and the IETF discuss at their
   meetings. Most people don't care about the long discussions; they only
   want to know how they'll be affected. So, here are highlights of the
   networking future.

New Standard Protocols

   When I was talking about how the Internet started, I mentioned the
   International Standards Organization (ISO) and their set of protocol
   standards. Well, they finally finished designing it. Now it is an
   international standard, typically referred to as the ISO/OSI (Open
   Systems Interconnect) protocol suite. Many of the Internet's component
   networks allow use of OSI today. There isn't much demand, yet. The U.S.
   government has taken a position that government computers should be
   able to speak these protocols. Many have the software, but few are
   using it now.

   It's really unclear how much demand there will be for OSI,
   notwithstanding the government backing. Many people feel that the
   current approach isn't broke, so why fix it? They are just becoming
   comfortable with what they have, why should they have to learn a new
   set of commands and terminology just because it is the standard?

   Currently there are no real advantages to moving to OSI. It is more
   complex and less mature than IP, and hence doesn't work as efficiently.
   OSI does offer hope of some additional features, but it also suffers
   from some of the same problems which will plague IP as the network gets
   much bigger and faster. It's clear that some sites will convert to the
   OSI protocols over the next few years.  The question is: how many?

International Connections

   The Internet has been an international network for a long time, but it
   only extended to the United States' allies and overseas military bases.
   Now, with the less paranoid world environment, the Internet is
   spreading everywhere. It's currently in over 50 countries, and the
   number is rapidly increasing. Eastern European countries longing for
   western scientific ties have wanted to participate for a long time, but
   were excluded by government regulation. This ban has been relaxed.
   Third world countries that formerly didn't have the means to
   participate now view the Internet as a way to raise their education and
   technology levels.

   In Europe, the development of the Internet used to be hampered by
   national policies mandating OSI protocols, regarding IP as a cultural
   threat akin to EuroDisney.  These policies prevented development of
   large scale Internet infrastructures except for the Scandinavian
   countries which embraced the Internet protocols long ago and are
   already well-connected.  In 1989, RIPE (Reseaux IP Europeens) began
   coordinating the operation of the Internet in Europe and presently
   about 25% of all hosts connected to the Internet are located in Europe.

   At present, the Internet's international expansion is hampered by the
   lack of a good supporting infrastructure, namely a decent telephone
   system. In both Eastern Europe and the third world, a state-of-the- art
   phone system is nonexistent. Even in major cities, connections are
   limited to the speeds available to the average home anywhere in the
   U.S., 9600 bits/second. Typically, even if one of these countries is
   "on the Internet," only a few sites are accessible. Usually, this is
   the major technical university for that country. However, as phone
   systems improve, you can expect this to change too; more and more,
   you'll see smaller sites (even individual home systems) connecting to
   the Internet.

Commercialization

   Many big corporations have been on the Internet for years. For the most
   part, their participation has been limited to their research and
   engineering departments. The same corporations used some other network
   (usually a private network) for their business communications. After
   all, this IP stuff was only an academic toy. The IBM mainframes that
   handled their commercial data processing did the "real" networking
   using a protocol suite called System Network Architecture (SNA).

   Businesses are now discovering that running multiple networks is
   expensive. Some are beginning to look to the Internet for "one-stop"
   network shopping. They were scared away in the past by policies which
   excluded or restricted commercial use. Many of these policies are under
   review and will change. As these restrictions drop, commercial use of
   the Internet will become progressively more common.

   This should be especially good for small businesses. Motorola or
   Standard Oil can afford to run nationwide networks connecting their
   sites, but Ace Custom Software couldn't. If Ace has a San Jose office
   and a Washington office, all it needs is an Internet connection on each
   end. For all practical purposes, they have a nationwide corporate
   network, just like the big boys.

Privatization

   Right behind commercialization comes privatization. For years, the
   networking community has wanted the telephone companies and other
   for-profit ventures to provide "off the shelf" IP connections.  That
   is, just like you can place an order for a telephone jack in your house
   for your telephone, you could do this for an Internet connection. You
   order, the telephone installer leaves, and you plug your computer into
   the Internet. Except for Bolt, Beranek and Newman, the company that ran
   the ARPAnet, there weren't any takers.  The telephone companies have
   historically said, "We'll sell you phone lines, and you can do whatever
   you like with them." By default, the Federal government stayed in the
   networking business.

   Now that large corporations have become interested in the Internet, the
   phone companies have started to change their attitude. Now they and
   other profit-oriented network purveyors complain that the government
   ought to get out of the network business. After all, who best can
   provide network services but the "phone companies"?  They've got the
   ear of a lot of political people, to whom it appears to be a reasonable
   thing. If you talk to phone company personnel, many of them still don't
   really understand what the Internet is about. They ain't got religion,
   but they are studying the Bible furiously. (Apologies to those
   telephone company employees who saw the light years ago and have been
   trying to drag their employers into church.)

   Although most people in the networking community think that
   privatization is a good idea, there are some obstacles in the way. Most
   revolve around the funding for the connections that are already in
   place. Many schools are connected because the government pays part of
   the bill. If they had to pay their own way, some schools would probably
   decide to spend their money elsewhere. Major research institutions
   would certainly stay on the net; but some smaller colleges might not,
   and the costs would probably be prohibitive for most secondary schools
   (let alone grade schools).  What if the school could afford either an
   Internet connection or a science lab? It's unclear which one would get
   funded. The Internet has not yet become a "necessity" in many people's
   minds. When it does, expect privatization to come quickly.

   Well, enough questions about the history of the information highway
   system. It's time to walk to the edge of the road, try and hitch a
   ride, and be on your way.

Acknowledgments

   We would like to thank O'Reilly & Associates for permission to reprint
   the chapter from their book by Ed  [7mKrol [m (1992), "The Whole
   Internet User's Guide and Catalog."

For More Information

   Hoffman, E. and L. Jackson. (1993) "FYI on Introducing the Internet --A
   Short Bibliography of Introductory Internetworking Readings for the
   Network Novice," 4 p.  (FYI 19, RFC 1463).

      To find out how to obtain this document and other on-line
      introductory readings, send an e-mail message to:
      [e-mail], with the following text: send access.guide.

   Krol, Ed. (1992) The Whole Internet User's Guide and Catalog, O'Reilly
   & Associates, Sebastopol, CA. ISBN 1-56592-025-2.

   Quarterman, J. (1993) "Recent Internet Books," 15 p. (RFC 1432).

   The Internet Society
   Phone: [phone]
   Fax: [phone]
   E-mail: [e-mail]

Authors' Addresses

   Ed Krol
   Computing and Communications Service Office
   Univ. of Illinois Urbana Champaign (UIUC)
   1304 W Springfield
   Urbana, IL 61801
   Phone: [phone]
   EMail: e- [7mkrol [[e-mail]

   Ellen Hoffman
   Merit Network, Inc.
   2901 Hubbard, Pod-G
   Ann Arbor, MI 48105
   Phone: [phone]
   EMail: [e-mail]
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