Network Standardization

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Many network vendors and suppliers exist, each with their own ideas of how things should be done. Without coordination, there would be complete chaos, and users would be able to get nothing done. The only way out is to agree upon some network standards.

Not only do standards allow different computers to communicate, they also increase the market for products adhering to the standard, which leads to mass production, economies of scale in manufacturing, and other benefits that decrease price and further increase acceptance.

We will take a quick look at the subject of international standardization.

Standards fall into two categories:

1. de facto, and

2. de jure.

De facto (Latin for "from the fact") standards are those that have just happened, without any formal plan. The IBM PC and its successors are defacto standards for small office computers because dozens of manufacturers have chosen to copy IBM's machines very closely. UNIX is the de facto standard for operating systems in university computer science departments.

De jure (Latin for "by law") standards, in contrast, are formal, legal standards adopted by some authorized standardization body.

International standardization authorities are generally divided into two classes:

1. Those established by treaty among national governments, and

2. Voluntary, non-treaty organizations.

In the area of computer network standards, there are several organizations of each type.

The Telecommunications world

The legal status of the world's telephone companies varies considerably from country to country.

At one extreme is the United States, which has 1500 separate, privately owned telephone companies. Before it was broken up in 1984, AT&T, at that time the world's largest corporation, completely dominated the scene. It provided telephone service to about 80 percent of America’s telephones, spread through-out half of its geographical area, with all the other companies combined servicing the remaining (mostly rural) customers. Since the breakup, AT&T continues to provide long-distance service, although now in competition with other companies. The seven Regional Bell Operating Companies that were split off from AT&T and 1500 independents provide local and cellular telephone service. Some of these independents are very large companies.

Companies in the United States that provide communication services to the public are called common carriers. Their offerings and prices are described by a document called a tariff, which must be approved by the Federal Communications Commission for the inter-state and international traffic, and by the state public utilities commissions for intrastate traffic.

At the other extreme are countries in which the national government has a complete monopoly on all communication, including the mail, telegraph, telephone, and often radio and television as well. Most of the world falls in this category. In some cases the telecommunication authority is a nationalized company, and in others it is simply a branch of the government, usually known as the PTT (Post, Telegraph & Telephone administration). Worldwide, the trend is towards liberalization and competition and away from government monopoly.

With all these different suppliers of services, there is clearly a need to provide compatibility on a worldwide scale to ensure that people (and computers) in one country can call their counterparts in another one.

Actually, this need has existed for a long time. In 1865, representatives from many European governments met to form the predecessor to today's ITU (International Telecommunication Union).

lTU's job was standardizing international telecommunications, which in those days meant telegraphy. Even then it was clear that if half the countries used Morse code and the other half used some other code, there was going to be a problem. When the telephone was put into international service, ITU took over the job of standardizing telephony as well. In 1947, ITU became an agency of the United Nations.

ITU has three main sectors:

1. Radio communications Sector (ITU-R)

2. Telecommunications Standardization Sector (ITU-T)

3. Development Sector (ITU-D)

ITU-R is concerned with allocating radio frequencies world wide to the competing interest groups.

We will be primarily concerned with ITU-T, which is concerned with telephone and data communication systems.

From 1956 to 1993, ITU-T was known as CCITT, an acronym for its French name: Comite Consultatif International Telegraphique et Telephonique.

Both ITU-T and CCITT issued recommendations in the area of telephone and data communications. One can still find CCITT recommendations, such as CCITT X.25, although since 1993 recommendations bear the ITU-T label.

ITU-T has five classes of members:

1. Administrations (national PTTs)

2. Recognized private operators (e.g., AT&T, MCI, British Telecom)

3. Regional telecommunications organizations (e.g., the European ETSI)

4. Telecommunications vendors and scientific organizations

5. Other interested organizations (e.g., banking and airline networks)

ITU-T's task is to make technical recommendations about telephone, telegraph, and data communication interfaces. These often become internationally recognized standards, for example, V.24 (also known as EIARS-232 in the United States), which specifies the placement and meaning of the various pins on the connector used by most asynchronous terminals.

It should be noted that lTU-T recommendations are technically only suggestions that governments can adopt or ignore, as they wish. In practice, a country that wishes to adopt a different telephone standard than the rest of the world is free to do so, but at the price of cutting itself off from everyone else.

The real work of lTU-T is done in Study Groups, often as large as 400 people. To make it possible to get anything at all done, the Study Groups are divided into Working Parties, which are in turn divided into Expert Teams, which are in turn divided into ad hoc groups.

As telecommunications completes the transition started in the 1980s from being entirely national to being entirely global, standards will become increasingly important.

The International Standards World

International standards are produced by ISO (International Standards Organization), a voluntary, non treaty organization founded in 1946. Its members are the national standards organizations of the 89 member countries. These members include ANSI (U.S.), BSI (Great Britain), AFNOR (France), DIN (Germany), and 85 others.

ISO issues standards on a vast number of subjects, ranging from nuts and bolts to telephone pole coatings.

ISO has 200+ Technical Committees, numbered in the order of their creation, each dealing with a specific subject. TC1 deals with the nuts and bolts (standardizing screw thread pitches). TC97 deals with computers and information processing. Each TC has sub-committees (SCs) divided into working groups (WGs).

The real work is done largely in the WGs by over 100,000 volunteers worldwide. Many of these "volunteers" are assigned to work on ISO matters by their employers, whose products are being standardized. Others are government officials keen on having their country's way of doing things become the international standard. Academic experts also are active in many of the WGs.

On issues of telecommunication standards, ISO and ITU-T often cooperate (ISO is a member of ITU-T).

The U.S. representative in ISO is ANSI (American National StandardsInstitute), which despite its name, is a private, non-governmental, non-profit organization. Its members are manufacturers, common carriers, and other interested parties. ANSI standards are frequently adopted by ISO as international standards.

The procedure used by ISO for adopting standards is designed to achieve as broad a consensus as possible. The process begins when one of the national standards organizations feels the need for an international standard in some area. A working group is then formed to come up with a CD (Committee Draft). The CD is then circulated to all the member bodies, which get 6 months to criticize it. If a substantial majority approves, a revised document, called a DIS (Draft International Standard) is produced and circulated for comments and voting. Based on the results of this round, the final text of the IS (International Standard) is prepared, approved, and published. In areas of great controversy, a CD or DIS may have to go through several versions before acquiring enough votes, and the whole process can take years.

NIST(National Institute of Standards and Technology) is an agency of the U.S. Dept. of Commerce. It was formerly known as the National Bureau of standards. It issues standards that are mandatory for purchases made by the U.S. Government, except for those of the Department of Defense, which has its own standards.

Another major player in the standards world is IEEE (Institute of Electrical and Electronics Engineers), the largest professional organization in the world. In addition to publishing scores of journals and running numerous conferences each year, IEEE has a standardization group that develops standards in the area of electrical engineering and computing. IEEE's 802 standard for local area networks is the key standard for LANs. It has subsequently been taken over by ISO as the basis for ISO8802.

The Internet Standards World

The worldwide Internet has its own standardization mechanisms, very different from those of lTU-T and ISO. The difference can be crudely summed up by saying that the people who come to ITU or ISO standardization meetings wear suits. The people who come to Internet standardization meetings wear either jeans or military uniforms.

ITU-T and ISO meetings are populated by corporate officials and government civil servants for whom standardization is their job. They regard standardization as a good thing and devote their lives to it.

Internet people, on the other hand, definitely prefer anarchy as a matter of principle, but sometimes agreement is needed to make things work. Thus standards, however regrettable, are occasionally needed.

When the ARPANET was set up, DoD created an informal committee to oversee it. In 1983, the committee was renamed the IAB (Internet Activities Board) and given a slightly broader mission, namely, to keep the researchers involved with the ARPANET and Internet. The meaning of the acronym lAB was later changed to Internet Architecture Board.

Each of the approximately ten members of the IAB headed a task force on some issue of importance. The IAB met several times a year to discuss results and give feedback to the DoD and NSF, which were providing most of the funding at this time. When a standard was needed (e.g., a new routing algorithm), the IAB members would thrash it out and then announce the change so the graduate students who were the heart of the software effort could implement it. Communication was done by a series of technical reports called RFCs (Request For Comments). RFCs are stored on-line and can be fetched by anyone interested in them. They are numbered in chronological order of creation.

By 1989, the Internet had grown so large that this highly informal style no longer worked. Many vendors by then offered TCP/IP products and did not want to change them just because ten researchers had thought of a better idea. In the summer of 1989, the IAB was reorganized again. The researchers were moved to the IRTF (Internet Research Task Force), which was made subsidiary to IAB, along with the IETF (Internet Engineering Task Force).

The IAB was repopulated with people representing a broader range of organizations than just the research community. It was initially a self-perpetuating group, with members serving for a 2-year term, and new members being appointed by the old ones.

Later, the Internet Society was created, populated by people interested in the Internet. The Internet Society is thus in a sense comparable to ACM or IEEE. It is governed by elected trustees who appoint the IAB members.

The idea of this split was to have the IRTF concentrate on long-term research, while the IETF dealt with short-term engineering issues.

To become a Proposed Standard, the basic idea must be completely explained in an RFC and have sufficient interest in the community to warrant consideration. To advance to the Draft Standard stage, there must be a working implementation that has been thoroughly tested by at least two independent sites for 4 months. If the IAB is convinced that the idea is sound and the software works, it can declare the RFC to be an Internet Standard. Some Internet Standards have become DoD standards (MIL-STD), making them mandatory for DoD suppliers.

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