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
` unlimited.
`
`Abstract
`
` 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.
`
`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.
`
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`RFC 1462 What is the Internet? May 1993
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` 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
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`RFC 1462 What is the Internet? May 1993
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` 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
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`RFC 1462 What is the Internet? May 1993
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` 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
`
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`RFC 1462 What is the Internet? May 1993
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` 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
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`RFC 1462 What is the Internet? May 1993
`
` 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.
`
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`RFC 1462 What is the Internet? May 1993
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` 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?
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`RFC 1462 What is the Internet? May 1993
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`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"
`
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`RFC 1462 What is the Internet? May 1993
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` 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
`
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` 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 Krol (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:
` nis-info@nis.merit.edu, 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: (703) 620-8990
` Fax: (703) 620-0913
` E-mail: isoc@cnri.reston.va.us
`
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`RFC 1462 What is the Internet? May 1993
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`Security Considerations
`
` Security issues are not discussed in this memo.
`
`Authors’ Addresses
`
` Ed Krol
` Computing and Communications Service Office
` Univ. of Illinois Urbana Champaign (UIUC)
` 1304 W Springfield
` Urbana, IL 61801
`
` Phone: (217)333-7886
` EMail: e-krol@uiuc.edu
`
` Ellen Hoffman
` Merit Network, Inc.
` 2901 Hubbard, Pod-G
` Ann Arbor, MI 48105
`
` Phone: (313) 936-3000
` EMail: ellen@merit.edu
`
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