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diff --git a/doc/rfc/rfc1462.txt b/doc/rfc/rfc1462.txt new file mode 100644 index 0000000..3ecf74e --- /dev/null +++ b/doc/rfc/rfc1462.txt @@ -0,0 +1,619 @@ + + + + + + +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. + + + + + +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 +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 [Page 2] + +RFC 1462 What is the Internet? May 1993 + + + 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 + + + +Krol & Hoffman [Page 3] + +RFC 1462 What is the Internet? May 1993 + + + 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 + + + +Krol & Hoffman [Page 4] + +RFC 1462 What is the Internet? May 1993 + + + 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 + + + +Krol & Hoffman [Page 5] + +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. + + + + +Krol & Hoffman [Page 6] + +RFC 1462 What is the Internet? May 1993 + + + 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? + + + + + + +Krol & Hoffman [Page 7] + +RFC 1462 What is the Internet? May 1993 + + +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" + + + +Krol & Hoffman [Page 8] + +RFC 1462 What is the Internet? May 1993 + + + 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 + + + +Krol & Hoffman [Page 9] + +RFC 1462 What is the Internet? May 1993 + + + 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 + + + + + + + + + + + + + + + + + +Krol & Hoffman [Page 10] + +RFC 1462 What is the Internet? May 1993 + + +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 + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Krol & Hoffman [Page 11] +
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