Yasutaka
Kato 加藤泰孝
<email:y.kato@personal.email.ne.jp>
Network Working Group E. Krol
Request for Comments: 1462 University of Illinois
FYI: 20 E. Hoffman
Merit Network, Inc.
May 1993
「インターネットとは？」についての FYI
FYI on "What is the Internet?"
この覚書の位置付け
この覚書はインターネット交流に関する情報を提供します。これはインター
ネット標準を特定するものではありません。この覚書の配布に制限はありませ
ん。
要約
このFYI RFC は「インターネットとは何ですか？」に答え、インターネット技
術特別調査委員会（IETF）のインターネット利用者サービス作業班によって作
成されています。Ed Krolの1992 本「The Whole Internet User's Guide and
Catalog」の抜粋も含まれ、この小冊は、インターネットの定義・歴史・管理
運営・プロトコール（手順）・経済そして成長・商業化・独占化なと最近の問
題を網羅しています。
はじめに
よく尋ねられる質問は、「インターネットとは何ですか？」というものです。
このような質問をしばしば受ける理由は、インターネットをきちんと要約する
答えについて同じ意見がないからです。インターネットは、その共通手順に関
連して、ルーターや回路の物理的な集積・一連の割り振られた資源乃至は相互
接続と相互交流の受け入れ方とさえ、考えることができます。以下のような今
迄に与えられたよくみる定義が幾つかあります：
* TCP/IP 手順に基づくネットワーク群のネットワーク、
* これらネットワーク群を使用・発展する人々の交流社会、
* これらのネットワーク群から手に取れる資源の集積
今日のインターネットは百万利用者を結び付ける地球規模の資源で、20年前米
国国防省の実験としてはじまりました。インターネットを構築するネットワー
クは、標準手順セットに基づいてますが（団体間の交流方法に相互に同じ意見
である）、インターネットはまた別の手順に基づいていりネットワークやサー
ビスへの門戸も開いています。
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RFC 1462 What is the Internet? May 1993
この質問により完全に答える手助けに、この文書は、より貫徹した説明をして
いるEd Krolの"The Whole Internet User's Guide and Catalog"(1992)の更新
版第二章を内容としています（この抜粋の出版を発行所、O'Reilly &
Associates, Inc.、は快く承託してくださいました）。
インターネット（「全インターネット利用者指針と目録」の抜粋）
インターネットは20年前に誕生し、アーパネット(ARPAnet) といわれる米国国
防省ネットワークとその他色々なダジオやサテライト（衛星放送）ネットワー
クを一緒に接続する試みをしました（ARPA＝Adcanced Research Projects
Agency 高等研究計画局）。アーパネットは軍事研究--特に、部分的な使用不
能（爆弾攻撃などで）に持ちこたえなお機能することができるネットワークを
如何に構築するかという研究--を支援するために企画された実験的なネット
ワークでした（私が、ネットワークはどのように機能するか、を説明する際、
これを思い出して下さい；これで、インターネット設計の思想が分かるでしょ
う）。アーパネットモデルで、資源と行き先のコンピューター間で、交流が常
に行われています。ネットワーク自体は不安定なものであると想定されていま
す；ネットワークのどの地点も、如何なる瞬間でも消失します（あなたも破局
を想像してください--掘削機がケーブルを切断する日は、爆弾よりもっと恐い
ものです）。コンピュータークライアントから最小情報を要求するように設計
されています。ネットワークでメッセージを送るにも、コンピューターはイン
ターネットプロトコール（IP）という封筒にデーターを入れその包に正しく宛
名を書くだけです。コンピューター交流は--ネットワークそのものでなく--も
交流が達成されることを保証する責任があります。その哲学は、コンピュー
ターは各々みんな、対等なものとして、どのようなコンピューターとも会話す
ることができる、ということでした。
これらの決定は、「不安定な」ネットワークの想定のように、意外にきこえる
かもしれませんが、これらは殆ど理に適っていて正しいかったと歴史が証明し
ています。国際規格組織（Organization for International Standardization
(ISO)） がコンピューターネットワーク作業の理想的な標準規格を企画するの
に数年を要しましたが、人々はまてませんでした。米国・英国そしてスカンジ
ナビアのインターネット開発者は、市場の圧力に応じて、自分のIPソフトウェ
アーを考えられる型のコンピューターに搭載しはじめました。それは、異なる
製造業者からのコンピューターが交流する実際的な方法となってきました。こ
れは、政府や全てのコンピューターは同じ売り手から購入すべきだという考え
（ポリシー）を持っていない大学にとって魅力的でした。各自それぞれみんな
が好きなコンピューターを購入し、コンピュウーターはネットワークを通じて
共に作動すると期待しました。
インターネットが導入されるようになってきたほぼ同じ頃、イサーネット地域
領域ネットワーク(LAN)が発展しました。この技術は、デスクトップワークス
テーションが1983年頃入手できるようになってくる迄には、完全に十分発達し
ていました。これらのワークステーションの多くは、バークレイ・ユニックス
と来て、IPネットワークソフトウェアーをともなっていました、これが新しい
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RFC 1462 What is the Internet? May 1993
要求を作りました：サイトに単一の大きな時分割コンピューターでなく、組織
団体は全ローカルネットワークにアーパネットを接続することを望みました。
これは、LAN 上の全てのコンピューターをアーパネット設備にアクセス可能に
しました。同じ頃、別の組織はアーパネットと同じ交流手順、つまりIPとその
縁者、を使って自身のネットワークを構築しはじめました。これらのネット
ワークが一緒に会話できれば、あるネットワークの利用者は別のものの利用者
と交流できることが明らかになってきました：全ての人がその恩恵を受けま
す。
これら新しいネットワークで最も重要なものの一つはNSFNETで、全米科学財団
（National Science Foundation (NSF)）、米国政府の一局、によって委任さ
れたものです。80年代後半、NSF は五つのスパーコンピューターセンターを作
りました。この時点まで、世界の最も速いコンピューターは武器開発者と少数
の大規模共同研究者が入手できるだけでした。スパーコンピューターセンター
を作ることで、NSF はそこの資源をどんな学問研究用でも入手できるようにし
ました。五つしかセンターは作られませんでした、というのは非常に高価でし
たから--で、振り分けられなければなりませんでした。これは交流問題を生み
ました：これらセンターを一緒に結び付け、センターのクライアントがアクセ
スできるようにする方法の必要性が出てきました。最初、NSF はアーパネット
を交流に使用することを試みましたが、この戦略は、官僚性と要員配置問題
で、失敗に終りました。
それに対してNSF は、それ自身のネットワーク、アーパネットのIP技術を基に
して、を構築することに決めました。56,000ビット／秒（56k bps）電話回線で
センターと接続しました（1秒に印刷物2ページを転送する能力です。それはモ
デム規格で遅くなりますが、80年代中頃では十分高速でした）。しかし、大学
みんなを直接スーパーコンピューターセンターに接続しようとすると、文無し
になることがはっきりしていました。車の車輪のスポークのように中軸のス
パーコンピューターセンターのあるキャンパス当りの回線は、何マイルもの電
話回線になります。従って、地域ネットワークを作ることにしました。その国
の各領域で、学校は一番近いとこに接続されます。各系列は一点でスパーコン
ピューターに接続され、そのセンターは全体的に接続されました。この設定で
やっと、どんなコンピューターでも近くから会話を送って別の人と交流できま
す。
この解決策は成功でした--そして、どんない成功解決策に見られるように、そ
れがもはや機能しない時がきました。スパーコンピューターの割り当によっ
て、接続されたサイトがセンターに関係ない別のものを多く分け持つことがで
きるようになりました。急速にこれらの学校が自分の手元にデーターや図書の
世界を持つようになりました。この結果、ネットワークを逝去するコンピュー
ターと電話回線接続が負担になるまでに、ネットワークのデーター通行量が増
大しました。1987年、そのネットワークの運営低下と更新が、IBM と MCIと協
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RFC 1462 What is the Internet? May 1993
力のもとにMichigan's educational networkを実行していたMerit Network
Inc、に与えられました。旧いネットワークは、高速電話回線（by a factor
of 20）、それを制御する高速コンピューターに置き代えられました。
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
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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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
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
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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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
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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
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