1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU X.904 (1 2/97) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N I CATI ON Open distributed processing Information technology - Open distributed processing - Reference Model: Architectural semantics ITU -T Re
2、com mend at ion X. 904 (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS Services and facilities Interfaces Transmission, signalling and switching Network aspects Maintenance Administrative arrangements OPEN SYSTEM INTER
3、CONNECTION Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specifications PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing INTERWORKTNG BETWEEN NETWORKS General Satellite data transmission
4、systems MESSAGE HANDLING SYSTEMS DIRECTORY OST NETWORKING AND SYSTEM ASPECTS Networking Efficiency Quality of service Naming, Addressing and Registration Abstract Syntax Notation One (ASN.1) OS1 MANAGEMENT Systems Management framework and architecture Management Communication Service and Protocol St
5、ructure of Management Information Management functions and ODMA functions SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing X. 1 -X. 1 9 X.20-X.49 X.50-X.89 X.90-X. 149 X. 150-X. 179 X. 180-X. 199 X.200-X.209 X.2 10-X.2 19 X.220-X.229 X.230-X.239 X.240-X.259 X.260
6、-X.269 X.270-X.279 X.280-X.289 X.290-X.299 X .3 00-X .349 X.350-X.399 X.400-X.499 X.500-X.599 X.600-X.629 X.630-X.639 X.640-X.649 X.650-X.679 X.680-X.699 X.700-X.709 X.7 1 0-X.7 1 9 X.720-X.729 X.730-X.799 X. 800-X. 849 X.850-X.859 X.860-X.879 Remote operations X.880-X.899 For fwther details, please
7、 refer to ITU-T Lisf of Recommendations. INTERNATIONAL STANDARD 10746-4 ITU-T RECOMMENDATION X.904 INFORMATION TECHNOLOGY - OPEN DISTRIBUTED PROCESSING - REFERENCE MODEL: ARCHITECTURAL SEMANTICS Summary This Recommendation I International Standard is an integral part of the ODP Reference Model. It c
8、ontains a formalisation of the ODP modelling concepts defined in ITU-T Rec. X.902 I ISOAEC 10746-2, clauses 8 and 9. The formalisation is achieved by interpreting each concept in terms of the constructs of the different standardised formal description techniques. Source The IT-T Recommendation X.904
9、 was approved on the 12th of December 1997. The identical text is also published as ISOAEC International Standard 10746-4. ITU-T Rec. X.904 (1997 E) 1 STD-ITU-T RECMN X-904-ENGL 1997 m 48b2591 Ob48097 834 m FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency
10、 in the field of telecommuni- cations. The IT Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The IT-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worl
11、dwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the IT-T Study Groups which, in their tuni, produce Recommendations on these topics. The approval of Recommendations by the Members of the IT-T is covered by
12、the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fali within IT-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate
13、both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concer
14、ning the evidence, validity or applicability of claimed Intellectual Properiy Rights, whether asserted by IT members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the IT had not received notice of intellectual property, protected by p
15、atents, which may be required to implement this Recommendation. However, impiementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O IW 1998 All rights reserved. No part of this publication may be reproduced or
16、utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 ITU-T Rec. X.904 (1997 E) STDmITU-T RECMN X.904-ENGL 1997 48b2591 Ob48098 770 CONTENTS O Introduction 1 Scope 2 Normative references . 3 Definitions 3.
17、1 Definitions from ISOAEC 8807 3.2 Definitions from ITU-T Recommendation 2.100 . 3.3 Definitions fiom the Z-Base Standard 3.4 Definitions from ISO/IEC 9074 Interpretation of modelling concepts 4.1 Architectural semantics in LOTOS . 4.2 Architectural semantics in ACT ONE . 4.3 Architectural semantics
18、 in SDL92 . 4.4 Architectural semantics in Z . 4.5 Architectural semantics in ESTELLE . 4 Page 1 2 2 2 2 2 3 3 3 3 9 15 20 25 ITU-T Rec . X.904 (1997 E) . 111 STDmITU-T RECMN Xm904-ENGL 1977 48b2591 Ob48099 bo7 Foreword This Recommendation I International Standard is an integral part of the ODP Refe
19、rence Model. It contains a formalisation of the ODP modeling concepts defined in ITU-T Rec. X.902 I ISOiEC 10746-2, clauses 8 and 9. The formalisation is achieved by interpreting each concept in terms of the constructs of the different standardised formal description techniques. This Recommendation
20、I International Standard is accompanied by an amendment and a technical report. The associated amendment focuses on the formalisation of the computational viewpoint language contained in IT-T Rec. X.903 I ISOIEC 10746-3. The associated technical report contains examples on how the formalisation of t
21、he ODP Reference Model can be applied to develop specifications. iv ITU-T Rec. X.904 (1997 E) STD-ITU-T RECMN X.904-ENGL 1997 = 4862571 Ob48100 159 ISO/IEC 10746-4 : 1998 (E) INTERNATIONAL STANDARD ITU-T RECOMMENDATION INFORMATION TECHNOLOGY - OPEN DISTRIBUTED PROCESSING - REFERENCE MODEL: ARCHITECT
22、URAL SEMANTICS O Introduction The rapid growth of distributed processing has lead to a need for a coordinating framework for the standardization of Open Distributed Processing (ODP). This Reference Model of ODP provides such a framework. It creates an architecture within which support of distributio
23、n, interworking, interoperability and portability can be integrated. The Basic Reference Model of Open Distributed Processing (RM-ODP), (see ITU-T Recs. X.901 to X.904 I ISO/IEC 10746), is based on precise concepts derived from current distributed processing developments and, as far as possible, on
24、the use of formal description techniques for specification of the architecture. The RM-ODP consists of: - ITU-T Rec. X.901 I ISO/IEC 10746-1: Overview: Contains a motivational overview of ODP giving scooping, justification and explanation of key concepts, and an outline of ODP architecture. This par
25、t is not normative. IT-T Rec. X.902 I ISO/IEC 10746-2: Foundations: Contains the definition of the concepts and analytical framework and notation for normalized description of (arbitrary) distributed processing systems. This is only to a level of detail sufficient to support ITU-T Rec. X.903 I ISOIE
26、C 10746-3 and to establish requirements for new specification techniques. This part is normative. - ITU-T Rec. X.903 I ISOAEC 10746-3: Architecture: Contains the specification of the required characteristics that qualifi distributed processing as open. These are the constraints to which ODP standard
27、s must conform. It uses the descriptive techniques from ITU-T Rec. X.902 I ISO/IEC 10746-2. This part is normative. ITU-T Rec. X.904 I ISOAEC 10746-4: Architectural Semantics: Contains a formalisation of the ODP modeling concepts defined in ITU-T Rec. X.902 I ISODEC 10746-2, clauses 8 and 9, and a f
28、ormalisation of the viewpoint languages of IT-T Rec. X.903 I ISOAEC 10746-3. The formalisation is achieved by interpreting each concept in terms of the constnicts of the different standardized formal description techniques. This part is normative. - - The purpose of this Recommendation I Internation
29、al Standard is to provide an architectural semantics for ODP. This essentially takes the form of an interpretation of the basic modeling and specification concepts of ITU-T Rec. X.902 I ISOiEC 10746-2 and viewpoint languages of ITU-T Rec. X.903 I ISOAEC 10746-3, using the various features of differe
30、nt formal specification languages. An architectural semantics is developed in four different formal specification languages: LOTOS, ESTELLE, SDL and Z. The result is a formalization of ODPs architecture. Through a process of iterative development and feedback, this has improved the consistency of IT
31、U-T Rec. X.902 I ISODEC 10746-2 and IT-T Rec. X.903 I ISOAEC 10746-3. An architectural semantics provides the additional benefits of: - - assisting the sound and uniform development of formal descriptions of ODP systems; and of permitting uniform and consistent comparison of formal descriptions of t
32、he same standard in different formal specification languages. Rather than provide a mapping from all the concepts of IT-T Rec. X.902 I ISOAEC 10746-2, this Recommendation I International Standard focuses on the most basic. A semantics for the higher level architectural concepts is provided indirectl
33、y through their definition in terms of the basic ODP concepts. Examples of the use of some of the formal specification languages in this report can be found in TR 10167 (Guidelines for the Application of ESTELLE, LOTOS and SDL). In the following clauses, the concepts are numbered in accordance with
34、the scheme used in ITU-T Rec. X.902 I ISODEC 10746-2. ITU-T Rec. X.904 (1997 E) 1 STDmITU-T RECMN X-904-ENGL 1777 M 4862571 0648101 075 ISO/IEC 10746-4 : 1998 (E) 1 Scope This Recommendation I International Standard specifies an architectural semantics for ODP. This is required to: - - - provide for
35、malisation of the ODP modelling concepts; assist sound and uniform development of formal descriptions of standards for distributed systems; act as a bridge between the ODP modelling concepts and the semantic models of the specification languages: LOTOS, SDL, ESTELLE and Z; provide a basis for unifor
36、m and consistent comparison between formal descriptions of the same standard in specification languages that are used to develop an architectural semantics. - This part is normative. 2 Normative references The following Recommendations and International Standards contain provisions which, through re
37、ference in this text, constitute provisions of this Recommendation I 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 I International Standard are e
38、ncouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and IS0 maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently
39、valid ITU-T Recommendations. ISOIIEC 8807:1989, Information processing systems - Open Systems Interconnection - LOTOS - A formal description technique based on the temporal ordering of observational behaviour. ITU-T Recommendation Z. 1 O0 (1 993), CCITT Specification and Description Language (SDL).
40、ISODEC TR 10167: 1991, Information technology - Open Systems Interconnection - Guidelines for the application of Estelle, LOTOS and SDL. ISOIIEC 135681, Information technology - Programming Languages their Environments and System Sofhvare Interfaces, Z Specijcation language. The Z Notation, A Refere
41、nce Manual, J.M. Spivey, international Series in Computer Science, Second Edition, Prentice-Hall International, 1992. ISOIIEC 9074:1997, information technology - Open Systems Interconnection - Estelle: A formal description technique based on an extended state transition model. - - - - - - 3 Definiti
42、ons 3.1 Definitions from ISO/IEC 8807 This Recommendation I International Standard makes use of the following terms defined in ISODEC 8807: action denotation, actualisation of parameters, behaviour expression, choice, conformance, disabling, enabling, enrichment, equation, event, extension, formal g
43、ate list, formal parameter list, gate, gate hiding, guard, instantiation, interleaving, internal observable event, operation, parallel composition, parameterised type definition, process definition, reduction, selection predicate, sort, synchronisation, type definition, value parameter list. 3.2 Thi
44、s Recommendation I International Standard makes use of the following terms defined in ITU-T Rec. Z. 100: action statement, active, atleust, block (type), call, channel, content parameter, continous signal, create, enabling condition, export, exported procedure, exported variable, finalized, gate, im
45、port, imported variable, input, nextstate, nodelay, now, output, procedure, process (type), provided, redeJined, remote procedure, reset, return, revealed variable, service (type), set, signal, signalroute, stop, system (type), task, time, timer, transition, view, viewed variable, virtual. Definitio
46、ns from ITU-T Recommendation 2.100 Currently at the stage of draft. 2 ITU-T Rec. X.904 (1997 E) ISO/IEC 10746-4 : 1998 (E) 3.3 Definitions from the Z-Base Standard This Recommendation I International Standard makes use of the following terms defined in the Z-Base Standard: axiomatic description, con
47、junction, data refinement, invariant, operation refinement, overriding, postcondition, precondition, schema (operation, state, ?amin, schema calculus, schema composition, 3.4 Definitions from ISODEC 9074 This Recommendation I Intemational Standard makes use of the following terms defined in ISO/IEC
48、9074: activitjy assignment statement, attach, channel, channel definition, connect, control state, DELAY-Clause, detach, disconnect, exported variable, external interaction point, FROM-Clause, function, init, instantiation, interaction, interaction point, module body definition, module header defini
49、tion, module instance, output, parent instance, primitive procedure, procedure, PROVIDED-Clause, release, role, systemactivity, systemprocess, TO-Clause, transition, transition block, transition clause, WHEN-clause. 4 Interpretation of modelling concepts 4.1 Architectural semantics in LOTOS LOTOS is a standardized (ISO/IEC 8807) Formal Specification Language (FSL). Tutorial material is available in the standard. This clause explains how the fundamental mo
