Research Standards

AA P P E N D I X P P E N D I X BB

SS T A N D A R D S T A N D A R D S OO R G A N I Z A T I O N SR G A N I Z A T I O N S

William Stallings Copyright 2009

B.1 THE IMPORTANCE OF STANDARDS ..........................................................................2

B.2 STANDARDS AND REGULATION ...............................................................................3

B.3 STANDARDS-SETTING ORGANIZATIONS ................................................................4

Internet Standards and the Internet Society ...................................................................4

The Internet Organizations and RFC Publication ..............................................5

The Standardization Process ..............................................................................6

Internet Standards Categories ............................................................................7

Other RFC Types ...............................................................................................8

The International Telecommunication Union ................................................................8

ITU Radio Communication Sector ....................................................................8

ITU Telecommunication Standardization Sector...............................................9

Schedule ...........................................................................................................10

IEEE 802 Committee ...................................................................................................10

ATM Forum .................................................................................................................12

The International Organization for Standardization ....................................................13

Supplement to

Business Data Communications, Sixth Edition

Prentice Hall 2009

ISBN: 0136067417

http://williamstallings.com/BDC/BDC6e.html

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An important concept that recurs frequently in this book is standards. This appendix provides

some background on the nature and relevance of standards and looks at the key organizations

involved in developing standards for networking and communications.

B.1 THE IMPORTANCE OF STANDARDS

It has long been accepted in the telecommunications industry that standards are required to

govern the physical, electrical, and procedural characteristics of communication equipment. In

the past, this view has not been embraced by the computer industry. Whereas communication

equipment vendors recognize that their equipment will generally interface to and communicate

with other vendors' equipment, computer vendors have traditionally attempted to monopolize

their customers. The proliferation of computers and distributed processing has made that an

untenable position. Computers from different vendors must communicate with each other and,

with the ongoing evolution of protocol standards, customers will no longer accept special-

purpose protocol conversion software development. The result is that standards now permeate all

the areas of technology discussed in this book.

There are a number of advantages and disadvantages to the standards-making process. The

principal advantages of standards are:

• A standard assures that there will be a large market for a particular piece of equipment or

software. This encourages mass production and, in some cases, the use of large-scale-

integration (LSI) or very-large-scale-integration (VLSI) techniques, resulting in lower

costs.

• A standard allows products from multiple vendors to communicate, giving the purchaser

more flexibility in equipment selection and use.

The principal disadvantages of standards are:

• A standard tends to freeze the technology. By the time a standard is developed, subjected to

review and compromise, and promulgated, more efficient techniques are possible.

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• There are multiple standards for the same thing. This is not a disadvantage of standards per

se, but of the current way things are done. Fortunately, in recent years the various

standards-making organizations have begun to cooperate more closely. Nevertheless, there

are still areas where multiple conflicting standards exist.

B.2 STANDARDS AND REGULATION

It is helpful for the reader to distinguish three concepts:

• Voluntary standards

• Regulatory standards

• Regulatory use of voluntary standards

Voluntary standards are developed by standards-making organizations, such as those

described in the next section. They are voluntary in that the existence of the standard does not

compel its use. That is, manufacturers voluntarily implement a product that conforms to a

standard if they perceive a benefit to themselves; there is no legal requirement to conform. These

standards are also voluntary in the sense that they are developed by volunteers who are not paid

for their efforts by the standards-making organization that administers the process. These

volunteers are generally employees of interested organizations, such as manufacturers and

government agencies.

Voluntary standards work because they are generally developed on the basis of broad

consensus and because the customer demand for standard products encourages the

implementation of these standards by the vendors.

In contrast, a regulatory standard is developed by a government regulatory agency to meet

some public objective, such as economic, health, and safety objectives. These standards have the

force of regulation behind them and must be met by providers in the context in which the

regulations apply. Familiar examples of regulatory standards are in areas such as fire codes and

health codes. But regulations can apply to a wide variety of products, including those related to

computers and communications. For example, the Federal Communications Commission

regulates electromagnetic emissions.

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A relatively new, or at least newly prevalent, phenomenon is the regulatory use of

voluntary standards. A typical example of this is a regulation that requires that the government

purchase of a product be limited to those that conform to some referenced set of voluntary

standards. This approach has a number of benefits:

• It reduces the rule-making burden on government agencies.

• It encourages cooperation between government and standards organizations to produce

standards of broad applicability.

• It reduces the variety of standards that providers must meet.

B.3 STANDARDS-SETTING ORGANIZATIONS

Various organizations have been involved in the development of standards related to data and

computer communications. The remainder of this document provides an overview of some of the

most important of these organizations:

• Internet Society

• ITU

• IEEE 802

• ATM Forum

• ISO

Internet Standards and the Internet Society

Many of the protocols that make up the TCP/IP protocol suite have been standardized or are in

the process of standardization. By universal agreement, an organization known as the Internet

Society is responsible for the development and publication of these standards. The Internet

Society is a professional membership organization that oversees a number of boards and task

forces involved in Internet development and standardization.

This section provides a brief description of the way in which standards for the TCP/IP

protocol suite are developed.

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THE INTERNET ORGANIZATIONS AND RFC PUBLICATION The Internet Society is the

coordinating committee for Internet design, engineering, and management. Areas covered

include the operation of the Internet itself and the standardization of protocols used by end

systems on the Internet for interoperability. Three organizations under the Internet Society are

responsible for the actual work of standards development and publication:

• Internet Architecture Board (IAB): Responsible for defining the overall architecture of

the Internet, providing guidance and broad direction to the IETF

• Internet Engineering Task Force (IETF): The protocol engineering and development

arm of the Internet

• Internet Engineering Steering Group (IESG): Responsible for technical management of

IETF activities and the Internet standards process

Working groups chartered by the IETF carry out the actual development of new standards

and protocols for the Internet. Membership in a working group is voluntary; any interested party

may participate. During the development of a specification, a working group will make a draft

version of the document available as an Internet Draft, which is placed in the IETF's "Internet

Drafts" online directory. The document may remain as an Internet Draft for up to six months,

and interested parties may review and comment on the draft. During that time, the IESG may

approve publication of the draft as an RFC (Request for Comment). If the draft has not

progressed to the status of an RFC during the six-month period, it is withdrawn from the

directory. The working group may subsequently publish a revised version of the draft.

The IETF is responsible for publishing the RFCs, with approval of the IESG. The RFCs are

the working notes of the Internet research and development community. A document in this

series may be on essentially any topic related to computer communications and may be anything

from a meeting report to the specification of a standard.

The work of the IETF is divided into eight areas, each with an area director and each

composed of numerous working groups. Table B.1 shows the IETF areas and their focus.

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Table B.1 IETF Areas

IETF Area Theme Example Working Groups

General IETF processes and procedures Policy Framework

Process for Organization of

Internet Standards

Applications Internet applications Web-related protocols (HTTP)

EDI-Internet integration

LDAP

Internet Internet infrastructure IPv6

PPP extensions

Operations and

management

Standards and definitions for

network operations

SNMPv3

Remote Network Monitoring

Routing Protocols and management for

routing information

multicast routing

OSPF

QoS routing

Security Security protocols and

technologies

Kerberos

IPSec

X.509

S/MIME

TLS

Transport Transport layer protocols Differentiated services

IP telephony

NFS

RSVP

THE STANDARDIZATION PROCESS The decision of which RFCs become Internet

standards is made by the IESG, on the recommendation of the IETF. To become a standard, a

specification must meet the following criteria:

• Be stable and well understood

• Be technically competent

• Have multiple, independent, and interoperable implementations with substantial

operational experience

• Enjoy significant public support

• Be recognizably useful in some or all parts of the Internet

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The key difference between these criteria and those used for international standards from

ITU is the emphasis here on operational experience.

The left-hand side of Figure B.1 shows the series of steps, called the standards track, that a

specification goes through to become a standard; this process is defined in RFC 2026. The steps

involve increasing amounts of scrutiny and testing. At each step, the IETF must make a

recommendation for advancement of the protocol, and the IESG must ratify it. The process

begins when the IESG approves the publication of an Internet Draft document as an RFC with

the status of Proposed Standard.

The white boxes in the diagram represent temporary states, which should be occupied for

the minimum practical time. However, a document must remain a Proposed Standard for at least

six months and a Draft Standard for at least four months to allow time for review and comment.

The shaded boxes represent long-term states that may be occupied for years.

For a specification to be advanced to Draft Standard status, there must be at least two

independent and interoperable implementations from which adequate operational experience has

been obtained.

After significant implementation and operational experience has been obtained, a

specification may be elevated to Internet Standard. At this point, the Specification is assigned an

STD number as well as an RFC number.

Finally, when a protocol becomes obsolete, it is assigned to the Historic state.

INTERNET STANDARDS CATEGORIES

All Internet standards fall into one of two categories:

• Technical specification (TS): A TS defines a protocol, service, procedure, convention, or

format. The bulk of the Internet standards are TSs.

• Applicability statement (AS): An AS specifies how, and under what circumstances, one

or more TSs may be applied to support a particular Internet capability. An AS identifies

one or more TSs that are relevant to the capability, and may specify values or ranges for

particular parameters associated with a TS or functional subsets of a TS that are relevant

for the capability.

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OTHER RFC TYPES There are numerous RFCs that are not destined to become Internet

standards. Some RFCs standardize the results of community deliberations about statements of

principle or conclusions about what is the best way to perform some operations or IETF process

function. Such RFCs are designated as Best Current Practice (BCP). Approval of BCPs follows

essentially the same process for approval of Proposed Standards. Unlike standards-track

documents, there is not a three-stage process for BCPs; a BCP goes from Internet draft status to

approved BCP in one step.

A protocol or other specification that is not considered ready for standardization may be

published as an Experimental RFC. After further work, the specification may be resubmitted. If

the specification is generally stable, has resolved known design choices, is believed to be well

understood, has received significant community review, and appears to enjoy enough community

interest to be considered valuable, then the RFC will be designated a Proposed Standard.

Finally, an Informational Specification is published for the general information of the

Internet community.

The International Telecommunication Union

The International Telecommunication Union (ITU) is a United Nations specialized agency.

Hence the members of ITU-T are governments. The U.S. representation is housed in the

Department of State. The charter of the ITU is that it "is responsible for studying technical,

operating, and tariff questions and issuing Recommendations on them with a view to

standardizing telecommunications on a worldwide basis." Its primary objective is to standardize,

to the extent necessary, techniques and operations in telecommunications to achieve end-to-end

compatibility of international telecommunication connections, regardless of the countries of

origin and destination.

ITU RADIO COMMUNICATION SECTOR The ITU Radiocommunication (ITU-R)

Sector was created on 1 March 1993 and comprises the former CCIR and IFRB (founded 1927

and 1947, respectively). ITU-R is responsible for all ITU's work in the field of radio

communications. The main activities of ITU-R are:

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• Develop draft ITU-R Recommendations on the technical characteristics of, and operational

procedures for, radiocommunication services and systems.

• Compile Handbooks on spectrum management and emerging radiocommunication services

and systems.

ITU-R is organized into the following study groups:

• SG1 Spectrum management

• SG3 Radiowave propagation

• SG 4 Fixed-satellite service

• SG 6 Broadcasting service (terrestrial and satellite)

• SG 7 Science services

• SG 8 Mobile, radiodetermination, amateur and related satellite services

• SG 9 Fixed service

• SC Special Committee on Regulatory/Procedural Matters

• CCV Coordination Committee for Vocabulary

• CPM Conference Preparatory Meeting

ITU TELECOMMUNICATION STANDARDIZATION SECTOR The ITU-T was created on 1

March 1993 as one consequence of a reform process within the ITU. It replaces the International

Telegraph and Telephone Consultative Committee (CCITT), which had essentially the same

charter and objectives as the new ITU-T. The ITU-T fulfils the purposes of the ITU relating to

telecommunications standardization by studying technical, operating and tariff questions and

adopting Recommendations on them with a view to standardizing telecommunications on a

worldwide basis.

ITU-T is organized into 14 study groups that prepare Recommendations, numbered as

follows:

2. Network and service operation

3. Tariff and accounting principles

4. Telecommunications management network and network maintenance

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5. Protection against electromagnetic environment effects

6. Outside plant

9. Integrated broadband cable networks and television and sound transmission

11. Signaling requirements and protocols

12. Performance and quality of service

13. Next generation networks

15. Optical and other transport networks infrastructures

16. Multimedia terminals, systems, and applications

17. Security, languages, and telecommunication software

19. Mobile telecommunications networks

SCHEDULE Work within ITU-R and ITU-T is conducted in four-year cycles. Every

four years, a World Telecommunications Standardization Conference is held. The work program

for the next four years is established at the assembly in the form of questions submitted by the

various study groups, based on requests made to the study groups by their members. The

conference assesses the questions, reviews the scope of the study groups, creates new or

abolishes existing study groups, and allocates questions to them.

Based on these questions, each study group prepares draft Recommendations. A draft

Recommendation may be submitted to the next conference, four years hence, for approval.

Increasingly, however, Recommendations are approved when they are ready, without having to

wait for the end of the four-year study period. This accelerated procedure was adopted after the

study period that ended in 1988. Thus, 1988 was the last time that a large batch of documents

was published at one time as a set of Recommendations.

IEEE 802 Committee

The key to the development of the LAN market is the availability of a low-cost interface. The

cost to connect equipment to a LAN must be much less than the cost of the equipment alone.

This requirement, plus the complexity of the LAN logic, dictates a solution based on the use of

chips and very-large-scale integration (VLSI). However, chip manufacturers will be reluctant to

commit the necessary resources unless there is a high-volume market. A widely accepted LAN

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standard assures that volume and also enables equipment from a variety of manufacturers to

intercommunicate. This is the rationale of the IEEE 802 committee.

The committee issued a set of standards, which were adopted in 1985 by the American

National Standards Institute (ANSI) as American National Standards. The standards were

subsequently revised and reissued as international standards by the International Organization for

Standardization (ISO) in 1987, with the designation ISO 8802. Since then, the IEEE 802

committee has continued to revise and extend the standards, which are ultimately then adopted

by ISO.

The committee quickly reached two conclusions. First, the task of communication across

the local network is sufficiently complex that it needs to be broken up into more manageable

subtasks. Accordingly, the standards are organized as a three-layer protocol hierarchy: Logical

Link Control (LLC), medium access control (MAC), and physical.

Second, no single technical approach will satisfy all requirements. The second conclusion

was reluctantly reached when it became apparent that no single standard would satisfy all

committee participants. There was support for various topologies, access methods, and

transmission media. The response of the committee was to standardize all serious proposals

rather than to attempt to settle on just one. The current state of standardization is reflected by the

various working groups in IEEE 802 and the work that each is doing (Table B.2)

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Table B.2 IEEE 802 Active Working Groups

Number Name Charter

802.1 Higher Layer LAN Protocols Standards and recommended practices for:

802 LAN/MAN architecture, internetworking

among 802 LANs, MANs, and other wide

area networks, 802 overall network

management, and protocol layers above the

MAC and LLC layers.

802.3 Ethernet Standards for CSMA/CD (Ethernet) based

LANs

802.11 Wireless LAN Standards for wireless LANs

802.15 Wireless Personal Area

Networks

Personal area network standards for short

distance wireless networks

802.16 Broadband Wireless Access Standards for broadband wireless access

802.17 Resilient Packet Ring Standards for RPR LAN/MAN for rates up to

many gigabits per second

802.18 Radio Regulatory TAG Monitor regulations that may affect 802.11,

802.15, and 802.16

802.19 Coexistence TAG

802.20 Mobile Broadband Wireless

Access

Standards for mobile broadband wireless

access

802.21 Media Independent Handoff Standards to enable handover and

interoperability between heterogeneous

network types including both 802 and non

802 networks

802.22 Wireless Regional Area

Networks

Standards for regional wireless networks

using unused frequencies in the broadcast

television band

ATM Forum

The ITU-T is responsible, among other areas, for the development of standards for Broadband

ISDN (B-ISDN), which is based on ATM technology. The ATM Forum also plays a crucial role

in the development of ATM standards. In the ITU-T and the constituent member bodies from the

participating countries, the process of developing standards is characterized by wide participation

by government, users, and industry representatives, and by consensus decision-making. This

process can be quite time consuming. While ITU-T has streamlined its efforts, the delays

involved in developing standards are particularly significant in the area of B-ISDN, which is

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dominated by the rapidly evolving asynchronous transfer mode (ATM) technology. Because of

the strong level of interest in ATM technology, the ATM Forum was created with the goal of

accelerating the development of ATM standards. The ATM Forum is an international nonprofit

organization, funded by over 600 member companies. End users are also represented within the

Forum.

The ATM Forum has seen more active participation from computing vendors than has been

the case in ITU-T. Because the forum works on the basis of majority rule rather than consensus,

it has been able to move rapidly to define some of the needed details for the implementation of

ATM. This effort, in turn, has fed into the ITU-T standardization effort.

The International Organization for Standardization

The International Organization for Standardization, or ISO, 1 is an international agency for the

development of standards on a wide range of subjects. It is a voluntary, nontreaty organization

whose members are designated standards bodies of participating nations, plus nonvoting

observer organizations. Although ISO is not a governmental body, more than 70 percent of ISO

member bodies are governmental standards institutions or organizations incorporated by public

law. Most of the remainder have close links with the public administrations in their own

countries. The United States member body is the American National Standards Institute.

ISO was founded in 1946 and has issued more than 12,000 standards in a broad range of

areas. Its purpose is to promote the development of standardization and related activities to

facilitate international exchange of goods and services and to develop cooperation in the sphere

of intellectual, scientific, technological, and economic activity. Standards have been issued to

cover everything from screw threads to solar energy. One important area of standardization deals

with the Open Systems Interconnection (OSI) communications architecture and the standards at

each layer of the OSI architecture.

In the areas of data communications and networking, ISO standards are actually developed

in a joint effort with another standards body, the International Electrotechnical Commission

(IEC). IEC is primarily concerned with electrical and electronic engineering standards. In the

1 ISO is not an acronym (in which case it would be IOS), but a word, derived from the Greek

isos, meaning "equal."

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area of information technology, the interests of the two groups overlap, with IEC emphasizing

hardware and ISO focusing on software. In 1987, the two groups formed the Joint Technical

Committee 1 (JTC 1). This committee has the responsibility of developing the documents that

ultimately become ISO (and IEC) standards in the area of information technology.

The development of an ISO standard from first proposal to actual publication of the

standard follows a six-step process. The objective is to ensure that the final result is acceptable to

as many countries as possible. Briefly, the steps are:

1. Proposal stage: A new work item is assigned to the appropriate technical committee, and

within that technical committee, to the appropriate working group.

2. Prepatory stage: The working group prepares a working draft. Successive working

drafts may be considered until the working group is satisfied that it has developed the

best technical solution to the problem being addressed. At this stage, the draft is

forwarded to the working group's parent committee for the consensus-building phase.

3. Committee stage: As soon as a first committee draft is available, it is registered by the

ISO Central Secretariat. It is distributed among interested members for balloting and

technical comment. Successive committee drafts may be considered until consensus is

reached on the technical content. Once consensus has been attained, the text is finalized

for submission as a Draft International Standard (DIS).

4. Enquiry stage: The DIS is circulated to all ISO member bodies by the ISO Central

Secretariat for voting and comment within a period of five months. It is approved for

submission as a Final Draft International Standard (FDIS) if a two-thirds majority is in

favor and not more than one-quarter of the total number of votes cast are negative. If the

approval criteria are not met, the text is returned to the originating working group for

further study and a revised document will again be circulated for voting and comment as

a DIS.

5. Approval stage: The Final Draft International Standard (FDIS) is circulated to all ISO

member bodies by the ISO Central Secretariat for a final yes/no vote within a period of

two months. If technical comments are received during this period, they are no longer

considered at this stage, but registered for consideration during a future revision of the

International Standard. The text is approved as an International Standard if a two-thirds

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majority is in favor and not more than one-quarter of the total number of votes cast are

negative. If these approval criteria are not met, the standard is referred back to the

originating working group for reconsideration in the light of the technical reasons

submitted in support of the negative votes received.

6. Publication stage: Once a Final Draft International Standard has been approved, only

minor editorial changes, if and where necessary, are introduced into the final text. The

final text is sent to the ISO Central Secretariat, which publishes the International

Standard.

The process of issuing an ISO standard can be a slow one. Certainly, it would be desirable

to issue standards as quickly as the technical details can be worked out, but ISO must ensure that

the standard will receive widespread support.

Best Current

Practice

Proposed

Standard

Draft

Standard

Internet

Standard

Figure B.1 Internet RFC Publication Process

Historic

Internet

Draft

Experimental Informational