1、STD-ITU-T RECMN XmSLO-ENGL 1998 48b259L Ob59481 99b INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU x.91 o (09/98) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS Open distributed processing Information technology - Open distributed processing - Nam
2、ing framework ITU-T Recommendation X.91 O (Previously CCITT Recommendation) ITU-T X-SERZES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS PUBLIC DATA NETWORKS Services and facilities Interfaces Transmission, signalling and switching Network aspects Maintenance Administrative arrangemen
3、ts Model and notation Service definitions Connection-mode protocol specifications Connectionless-mode protocol specifications PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing General Satellite data transmission systems MESSAGE HANDLING SYSTEMS DIREC
4、TORY OS1 NETWORKING AND SYSTEM ASPECTS OPEN SYSTEMS INTERCONNECTION INTERWORKING BETWEEN NETWORKS Networking Efficiency Quality of service Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) Systems Management framework and architecture Management Communication Service and Proto
5、col Structure of Management Information Management functions and ODMA functions OS1 MANAGEMENT SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing X.l-X.19 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.210-X.219 X.220-X.229 X.230-X.239 X.240-X
6、.259 X.260-X.269 X.270-X.279 X.280-X.289 X.290-X.299 x.300-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.710-X.719 X.720-X.729 x.730-x.799 X.800-X. 849 X.850-X.859 X.860-X.879 Remote oDerations x 88n-x 899 Forjrther details, pl
7、ease refer to ITU-T List of Recommendations. STDoITU-T RECMN X-910-ENGL L398 = 48b259L Ob59483 7b9 W INTERNATIONAL STANDARD 14771 ITU-T RECOMMENDATION X.910 INFORMATION TECHNOLOGY - OPEN DISTRIBUTED PROCESSING - NAMING FRAMEWORK Summary This Recommendation I International Standard expands the naming
8、 concepts introduced in the Reference Model for Open Distributed Processing. It provides a general framework for naming in heterogeneous distributed systems, giving concepts and procedures which support fully general context-relative naming. These concepts can be applied in any ODP viewpoint. They c
9、an be applied to any function which uses naming and is subject to distribution and federation. Source The ITU-T Recommendation X.910 was approved on the 25th of September 1998. The identical text is also published as ISOhEC International Standard 1477 1. ITU-T Rec. X.910 (1998 E) i STD*ITU-T RECMN X
10、mSLO-ENGL 1978 46b2591 Ob59464 bT5 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni- cations. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying techn
11、ical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which
12、, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a co
13、llaborative basis with IS0 and IEC. NOTE In this Recommendation the term recognized operating agency (ROA) includes any individual, company, corporation or governmental organization that operates a public correspondence service. The terms Administration, RUA and public correspondence are defined in
14、the Constitution of the ITU (Geneva, 1992). 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 concerning the evidence, validity or
15、applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required
16、 to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 1999 All rights reserved. No part of this publication may be reproduced or utilized in any form or by a
17、ny means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 ITU-T Rec. X.910 (1998 E) STD-ITU-T RECMN X-910-ENGL 1998 D 48b2591 Ob59485 531 1 2 3 4 5 6 7 8 9 10 11 CONTENTS scope Normative references 2.1 Identical Recommendations I Interna
18、tional Standards . Definitions 3.1 Terms defined in other International Standards Abbreviations . Overview of ODP naming 5.1 Introduction . 5.2 Stnicture of naming contexts . 5.3 Processes involving names Basic Naming Concepts Name resolution model . 7.1 The name resolution step . 7.2 The complete n
19、ame resolution process Name communication . Name comparison . Federation . 10.1 Controlling the names exported - export contexts 10.2 Uniform naming of federation partners - federation contexts 10.3 Providing a uniform user view of federated naming . 10.4 Joining a federation . 10.5 Evolution and op
20、timization . Compliance . 11.1 Basis for compliance . 1 1.2 Compliance requirements Annex A . Relationship with Related Naming Services and Frameworks Relationship with OMG Object Naming Service Relationship with WOpen Federated Naming API . Relationship with OS1 Naming and Addressing . Annex B - Co
21、nfiguring name services B . 1 Quality of name service concerns B.2 Distributing the name service B.3 Configuring name servers . Annex C - Application of Naming Annex D - Bibliography A.l A.2 A.3 Page 1 1 1 1 2 2 2 2 3 5 5 7 7 8 9 10 10 10 11 12 13 13 14 14 15 16 16 16 17 18 18 18 19 23 24 Index 25 I
22、TU-T Rec . X.910 (1998 E) . 111 STDOITU-T RECMN X*SLO-ENGL 1998 D 48b2591 Ob5948b 478 = Introduction Names and naming are central concepts for the design and construction of open distributed systems. Most existing systems are built upon the assumption of a naming scheme in which only one selected na
23、ming convention applies to all the entities of concern (a global naming scheme). This assumption proves unsatisfactory in the context of large, evolving, heterogeneous distributed systems, managed by different authorities. Therefore, ITU-T Recs. X.9Ox series I ISO/IEC 10746, the Reference Model for
24、Open Distributed Processing (ODP-RM), defines names to be context-relative. This Recommendation I International Standard expands on the naming concepts introduced in the ODP-RM. it provides a general framework for naming, giving concepts and procedures which support fully general context-relative na
25、ming. These concepts can be applied in any ODP viewpoint. They can be applied to any function which uses naming and is subject to distribution or federation. iv ITU-T Rec. X.910 (1998 E) - - - - - STD-ITU-T RECMN X*SLO-ENGL 1998 9 48b259L Ob59487 304 9 ISO/IEC 14771 : 1999 (E) INTERNATIONAL STANDARD
26、 ITU-T RECOMMENDATION INFORMATION TECHNOLOGY - OPEN DISTRIBUTED PROCESSING - NAMING FRAMEWORK 1 Scope This Recommendation I International Standard: - defines a general framework for context-relative naming, refining and elaborating on the naming concepts defined in Pari 2 of the ODP-RM; - identifies
27、 and characterizes functions necessary to handle names in the context of a federation of different naming systems; and clarifies the relationship between the concepts of name management (Le. federation and naming) in distributed computing systems. - It provides a general framework for the naming of
28、entities of interest in ODP systems, which includes naming in the infrastructure of an ODP system, naming in the applications built on the infrastructure, and naming in the enterprise the system serves. 2 Normative references The following ITU-T Recommendations and International Standards contain pr
29、ovisions which, through reference 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 In
30、ternational Standard are encouraged 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 Telecommunications Standards Bureau of the ITU maintains
31、 a list of currently valid ITU-T Recommendations. 2.1 Identical Recommendations I International Standards - - - ITU-T Recommendations X9Ox series I ISO/IEC 10746, Open Distributed Processing. IT-T Recommendations X.500 series I ISO/IEC 9594 (all parts): The Directory. ITU-T Recommendation X.650 (199
32、6) I ISOAEC 7498-3: 1997, Information technology - Open Systems Interconnection - Basic reference model: Naming and addressing. ITU-T Recommendation X.902 (1995) I ISOAEC 10746-2:1996, Information technology - Open - - Distributed Processing - Reference. Model: Foundations. - ITU-T Recommendation X.
33、903 (1995) I ISO/IEC 10746-3:1996, Information technology Distributed Processing - Reference Model: Architecture. 3 Definitions For the purposes of this Recommendation I International Standard, the following terms and definitions apply: ITU-T Rec. X.910 (1998 E) Open 1 _ STDmITU-T RECMN XmSLO-ENGL 1
34、998 W 48b2591 0659468 240 ISOAEC 14771 : 1999 (E) 3.1 This Recommendation I International Standard makes use of the following terms defined in ITU-T Rec. X.902 I Terms defined in other International Standards ISO/IEC 10746-2: - ODPsystem; - viewpoint; - name; - identifier; - namespace; - naming cont
35、ext; - naming action; - naming domain; - naming graph; - name resolution; - cXdomain. This Recommendation I International Standard makes use of the following terms defined in IT-T Rec. X.903 I ISO/IEC 10746-3: - ODP function; - ODPsystem; - location transparency; - migration transparency; - communit
36、y; - federation; - operation. 4 Abbreviations For the purpose of this Recommendation I International Standard, the following abbreviations apply: ODP Open Distributed Processing OS1 Open Systems Interconnection XFN WOpen Federated Naming 5 Overview of ODP naming 5.1 Introduction ITU-T Rec. X.902 I I
37、SOAEC 10746-2 introduces the basic ODP naming concepts. This clause provides an informal discussion of the naming structures supported by those concepts. In principle, using the ODP concepts, it would be possible to construct a single universal naming context for distributed systems - a global namin
38、g scheme. In such a naming scheme only one selected naming convention would apply to ail the entities of concern in the ODP system. Names in such a scheme are usually referred to as absolute names, although they are, in fact, relative to a single agreed context from which all name resolution starts.
39、 Such a scheme is based on the assumption that all the parties participating in distributed processing follow the same naming scheme. This implies that: - - all the parties in the ODP systems agree to use the same naming convention; there is a relevant name authority to administer the scheme. These
40、conditions can apply in some specialized environments or for systems administered by a single administration. However, a truly global scheme would require agreement on a universal name space to be used in the naming of any entities that require naming, and a universal mapping between the names from
41、the name space and the entities. Many 2 ITU-T Rec. X.910 (1998 E) STD-ITU-T RECMN X-910-ENGL 1998 48b2591 Ob59489 187 ISO/IEC 14771 : 1999 (E) independently developed naming schemes have already been implemented and many more are being proposed. The ODP naming model must accommodate these different
42、naming schemes and allow their interconnection. A single universal naming context would not support the necessary heterogeneity, and could not be managed. Moreover, in a very large naming system, naming must remain unambiguous and the name space must therefore be equally large. Each naming action mu
43、st be checked for consistency with the effects of ail previous naming actions. The time required for a naming action will thus become related to the number of previous naming actions, making the availability of the naming action process unpredictable. The performance of the naming action process can
44、 only be increased at the cost of reduced consistency; some names may be used more than once (creating homonyms) and name resolution becomes ambiguous. A context-reluive naming scheme allows the federation of naming contexts and solves many of these problems. In a context-relative naming scheme, mul
45、tiple naming contexts can apply to entities in different administrative domains of the ODP system, but these naming contexts can be related to one another, so that it is possible to refer from one naming context to an entity in another naming context. In order to achieve this, in addition to associa
46、ting a name with an entity, a naming action can also associate a name with another naming context. Since a naming context is something of interest, it is an entity and can be named. Such an approach provides: - the ability to avoid the need for unmanageably large naming systems; - autonomy of the el
47、ements of open distributed processing systems, so that elements administered under different naming schemes continue to work on their own, but can work together; - ease in reaching agreements and getting commitments on a naming scheme, since smaller communities are involved, which can then be brough
48、t together to form a global ODP community by federating their naming schemes; - efficient and compact representation of names within local communities; - the ability to incorporate different existing “global“ naming schemes. Thus, the naming process and management of consistency of names become mana
49、geable problems and existing naming contexts can be accommodated. 5.2 Structure of naming contexts Any large distributed system is likely to comprise a number of administrative and technology domains. As a result, it is likely that the system also comprises a number of naming contexts, each relating to a name space and a set of target entities. At any given time, not all of the names from the name space, and not all of the entities from the set of target entities will be involved in a naming context. Where a number of naming contexts exist, it may at times be nece
