1、BRITISH STANDARD BS ISO/IEC 13236:1998 Information technology Quality of service: Framework ICS 35.020BSISO/IEC13236:1998 This BritishStandard, having been prepared under the directionof the DISC Board, waspublished under the authorityof the Standards Committee and comes into effecton 15May1999 BSI0
2、3-2000 ISBN 0 580 32381 1 National foreword This BritishStandard reproduces verbatim ISO/IEC13236:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee IST/6, Data communications, which has the responsibility to: aid enquirer
3、s to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations repre
4、sented on this committee can be obtained on request to its secretary. Cross-references The BritishStandards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Corresponden
5、ce Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of it
6、self confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theISO/IEC title page, pagesii toiv, pages1 to48 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. T
7、his will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO/IEC13236:1998 BSI 03-2000 i Contents Page National foreword Inside front cover Foreword iv Text of ISO/IEC13236 1ii blankBSISO/IEC13236:1998 ii BSI 03-2000 Contents
8、 Page Foreword iv Introduction 1 1 Scope 1 2 Normative references 2 2.1 Identical Recommendations|International Standards 2 2.2 Paired Recommendations|International Standards equivalent in technicalcontent 2 2.3 Additional references 3 3 Definitions 3 3.1 Basic Reference Model of Open Distributed Pr
9、ocessing definitions 3 3.2 Basic Reference Model OSI Management Framework definitions 3 3.3 Service Conventions definitions 3 3.4 OSI Basic Reference Model definitions 3 3.5 QOS Framework definitions 3 4 Abbreviations 5 5 Concepts of this QOS Framework 6 5.1 Introduction 6 5.2 The service to which Q
10、OS applies 6 5.3 QOS characteristics 7 5.4 User QOS requirements and QOS policies 7 5.5 QOS requirements, QOS parameters and QOS context 7 5.6 QOS management functions and QOS mechanisms 8 5.7 QOS categories 9 5.8 Initiation of QOS management 9 6 Definition of QOS characteristics 9 6.1 Introduction
11、9 6.2 Aspects of QOS characteristic definition 9 6.3 QOS characteristics of general importance 12 6.4 Fundamental QOS categories 21 7 QOS management 22 7.1 Introduction 22 7.2 Prediction phase 24 7.3 Establishment phase 24 7.4 Operational phase 27 7.5 Supporting services 28 8 General QOS mechanisms
12、28 8.1 Introduction 28 8.2 Prediction phase mechanisms 28 8.3 Establishment phase mechanisms 29 8.4 Operational phase mechanisms 30 9 Specific QOS requirements 33 9.1 QOS requirements related to single QOS characteristics 33 9.2 QOS requirements related to multiple characteristics 34 10 QOS verifica
13、tion 34 10.1 Introduction and stages 34 10.2 QOS verification concepts 34 11 Conformance, consistency and compliance 35 11.1 Conformance and the inter-relationship of standards 35 11.2 Definitions 35 11.3 Application of consistency and compliance requirements 36BSISO/IEC13236:1998 BSI 03-2000 iii Pa
14、ge 11.4 Consistency and compliance with ITU-T Rec.X.200| ISO/IEC7498-1 36 Annex A The model of QOS for OSI 37 A.1 Introduction 37 A.2 Architectural principles 37 A.3 Motivation for the provision of QOS 38 A.4 Information flows in the model 38 A.5 Layer model of QOS for OSI 41 A.6 System model of QOS
15、 in OSI 44 Annex B Definitions of statistical derivations of characteristics 45 Annex C Relationships between QOS Recommendations| InternationalStandards and other Recommendations| InternationalStandards 46 Annex D Cost Information 47 Annex E QOS Bibliography 48 Figure 5-1 Relationships between QOS
16、concepts 7 Figure 6-1 Derived characteristics and specialisations 11 Figure 6-2 Relationship between freshness and lifetime 15 Figure 7-1 QOS thresholds and limit 25 Figure 7-2 General threshold 26 Figure 8-1 System internal tuning mechanism 32 Figure 8-2 System external tuning mechanism 32 Figure 1
17、0-1 QOS verification statement 35 Figure A.1 The relationship for system to layer QOS entity 37 Figure A.2 The requirement for QOS 38 Figure A.3 Example of flow of QOS requirements in an unconfirmed (N)-service-facility 39 Figure A.4 Example of flow of QOS requirements in a confirmed (N)-service-fac
18、ility 39 Figure A.5 Outgoing flow of QOS requirements inside an (N)-subsystem 40 Figure A.6 Incoming flow of QOS requirements inside an (N)-subsystem 40 Figure C.1 Relationship between documents 46 Table 6.1 Table of characteristics 13BSISO/IEC13236:1998 iv BSI 03-2000 Foreword ISO (the Internationa
19、l Organization for Standardization) and IEC (theInternational Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by t
20、he respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of i
21、nformation technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least75% of the nationa
22、l bodies casting a vote. International Standard ISO/IEC13236 was prepared by Joint Technical Committee ISO/IEC JTC1, Information technology, Subcommittee SC33, Distributed application services, in collaboration with ITU-T. The identical text is published as ITU-T Recommendation X.641. Annex A forms
23、an integral part of this International Standard. Annex B to Annex E are for information only.BSISO/IEC13236:1998 BSI 03-2000 1 Introduction The purpose of this Recommendation|International Standard is to provide a common basis for the coordinated development and enhancement of the wide range of stan
24、dards that specify or reference Quality of Service (QOS) requirements or mechanisms in an Information Technology (IT) environment. It offers a means of developing or enhancing standards relating to QOS and provides concepts and terminology that will assist in maintaining the consistency of related s
25、tandards. This Recommendation|International Standard is complementary to existing ITU-T Recommendations which define performance objectives and network signalling of QOS and it is not the intention of this Framework to lead to a need to revise any such Recommendations. The initial work in developing
26、 this Framework for QOS was done with the objective of supplementing and clarifying the description of QOS contained in the Basic Reference Model of Open Systems Interconnection (OSI) (see ITU-T Rec.X.200|ISO/IEC7498-1). It is recognised, however, that management of QOS is important not only in OSI
27、communications but also in a much wider context, and that there is value in encouraging a common approach to QOS that can extend to other IT and communications architectures, to distributed processing in general and to Open Distributed Processing (ODP) in particular. Hence this Recommendation|Intern
28、ational Standard is structured and written in such a way as to make it easy for many communities to adopt its approach, concepts, terminology and definitions. Its concepts and terms are defined without reference to any particular architecture, so that they can be adopted and applied by other communi
29、ties to a variety of architectures and protocols. This general treatment is supplemented by examples from OSI, ODP and elsewhere. To assist the OSI community, Annex A defines how the general framework applies to the specific case of OSI communications, both peer-to-peer and multi-peer. This QOS Fram
30、ework contains an introduction, a scope and field of application and a set of QOS-related definitions and abbreviations. The concepts of QOS are introduced in clause5, which also highlights user requirements. Clause6 defines QOS characteristics with respect to the user requirements. Clauses7, 8 and9
31、 cover QOS management, QOS mechanisms and the expression of specific QOS requirements, respectively. QOS verification is discussed in clause10, and conformance, consistency and compliance are discussed in clause11. Annexes are provided which stipulate: the model of QOS for OSI; statistical derivatio
32、ns of characteristics; a standards structure with respect to QOS; a discussion of the issue of “cost”; and a bibliography. Other standards communities are encouraged to study this Recommendation|International Standard and, in the interests of consistency, to consider the adoption of the parts that a
33、re relevant to their field, when this can be accomplished to good effect, without destabilisation of existing Recommendations| International Standards. 1 Scope This QOS Framework is a structured collection of concepts and their relationships which describes QOS (Quality of Service) and enables the p
34、artitioning of, and relationships between, the topics relevant to QOS in Information Technology (IT) to be expressed by a common means of description. In particular, this QOS Framework is directed at IT systems and their use in providing Open Distributed Processing services. This QOS Framework is in
35、tended to assist those designing and specifying IT systems, and those defining communications services and protocols, by providing guidance on QOS applicable to systems, services and resources of various kinds. It describes how QOS can be characterized, how QOS requirements can be specified, and how
36、 QOS can be managed. This QOS Framework defines terminology and concepts for QOS in IT. It introduces the concept of QOS characteristics, which represent the fundamental aspects of QOS that are to be managed in various ways; and it defines a number of QOS characteristics of particular importance. Th
37、ese definitions are independent of how QOS is represented or controlled in a real system.BSISO/IEC13236:1998 2 BSI 03-2000 This Framework describes how QOS requirements can be expressed, and identifies a number of QOS mechanisms (such as three-party negotiation) that can be used as components of QOS
38、 management functions to meet QOS requirements of various kinds. It also describes the circumstances in which various combinations of mechanisms may be appropriate. This QOS Framework provides a basis for the specification of extensions and enhancements to existing or planned standards, as a result
39、of the need for, and application of, the QOS concepts defined in this Recommendation|International Standard. It is not the intent of this Recommendation|International Standard to destabilise any existing Recommendations|International Standards; rather, it is intended that this QOS Framework may be u
40、sed by: developers of new or revised IT-related standards which define or use QOS mechanisms; and IT users expressing requirements for QOS. This QOS Framework does not attempt to provide a basis for the specification of performance objectives or network signalling of QOS in public communications net
41、works. The QOS aspects of these communications services are addressed by other ITU-T Recommendations. The intent of this Recommendation|International Standard is to provide a common vocabulary to both service providers and service users. Nothing in this Recommendation|International Standard should b
42、e construed as placing requirements on either service providers or service users. It is hoped that a common approach and vocabulary for QOS will assist multiple service providers to deliver end-to-end QOS to end-systems. This QOS Framework specifically excludes the detailed specification of QOS mech
43、anisms. It is not the intent of this Recommendation|International Standard to serve as an implementation specification, to be a basis for appraising the conformance of implementations, or to define particular services and protocols. Rather, it provides a conceptual and functional framework for QOS w
44、hich allows independent teams of experts to work productively on the development of Recommendations|International Standards. As applied to OSI, this QOS Framework is consistent with the OSI Basic Reference Model in that it describes operations and mechanisms which are assignable to layers as specifi
45、ed in the OSI Basic Reference Model. It is consistent with the OSI Management Framework (see ITU-T Rec. X.700| ISO/IEC7498-4) and the Systems Management Overview (see ITU-T Rec. X.701|ISO/IEC10040) in its assignment of functions to management entities. In Annex A, this QOS Framework presents a model
46、 of QOS for OSI which identifies the entities that participate in the management of QOS, defines the flow of QOS-related information between them and describes how this information is used. 2 Normative references The following Recommendations and International Standards contain provisions which, thr
47、ough reference in this text, constitute provisions of this Recommendation|International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation|International Standard ar
48、e encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of current
49、ly valid ITU-T Recommendations. 2.1 Identical Recommendations|International Standards ITU-T Recommendation X.200 (1994)|ISO/IEC7498-1:1994, Information technology Open Systems Interconnection Basic Reference Model: The Basic Model. ITU-T Recommendation X.210 (1993)|ISO/IEC10731:1994, Information technology Open Systems Interconnection Basic Reference Model: Conventions for the definition of OSI services. ITU-T Recommendation X.746 (1995)|ISO/IEC10164-15:1995, Information technology Open Systems Interconnection Syst
