1、INTERNATIONAL TELECOMMUNICATION UNIONITU-T Z.600TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU(11/2000)SERIES Z: LANGUAGES AND GENERAL SOFTWAREASPECTS FOR TELECOMMUNICATION SYSTEMSDistributed processing environmentarchitectureCAUTION !PREPUBLISHED RECOMMENDATIONThis prepublication is an unedited vers
2、ion of a recently approved Recommendation.It will be replaced by the published version after editing. Therefore, there will bedifferences between this prepublication and the published version.FOREWORDThe International Telecommunication Union (ITU) is the United Nations specialized agency in the fiel
3、d oftelecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ ofITU. ITU-T is responsible for studying technical, operating and tariff questions and issuingRecommendations on them with a view to standardizing telecommunications on a worldwide basis.The World T
4、elecommunication Standardization Assembly (WTSA), which meets every four years,establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations onthese topics.The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.In some ar
5、eas of information technology which fall within ITU-Ts purview, the necessary standards areprepared on a collaborative basis with ISO and IEC.NOTEIn this Recommendation, the expression “Administration“ is used for conciseness to indicate both atelecommunication administration and a recognized operat
6、ing agency.INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation mayinvolve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence,validity or applicability of claimed Intellectual Proper
7、ty Rights, whether asserted by ITU members or othersoutside of the Recommendation development process.As of the date of approval of this Recommendation, ITU had/had not received notice of intellectualproperty, protected by patents, which may be required to implement this Recommendation. However,impl
8、ementors are cautioned that this may not represent the latest information and are therefore stronglyurged to consult the TSB patent database. ITU 2001All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical, including photoco
9、pying and microfilm, without permission in writing from ITU.ITU-T Z.600 (11/2000) Prepublished version 1ITU-T RECOMMENDATION Z.600DISTRIBUTED PROCESSING ENVIRONMENT ARCHITECTURE_CONTENTSPage1 Summary. 42 Scope. 42.1 Purpose 52.2 Objective. 62.3 Non-objectives 63 References. 63.1 Identical Recommenda
10、tion | International Standards . 63.2 Other Specifications 64 Definitions 74.1 Terms defined in the ODP Reference Model: Foundations 74.2 Terms defined in the ODP Reference Model: Architecture . 74.3 Definitions for Distributed Processing Environment Architecture. 75 Abbreviations 86 Introduction. 9
11、6.1 DPE Architecture 106.2 DPE Reference Points. 106.3 Extensions to CORBA 117 Engineering Modelling Concepts . 137.1 Object Life Cycle 137.2 Communication in the DPE 147.2.1 Operational communication 147.2.2 Stream communication . 147.3 Computational to engineering view mapping. 157.4 Bindings 157.
12、4.1 Operational vs. Stream Binding 157.4.2 Explicit vs. Implicit bindings 157.5 Channels 16ITU-T Z.600 (11/2000) Prepublished version 27.6 Elaboration on the bindings 177.6.1 Introduction. 177.6.2 Programmable stream interfaces. 187.6.3 Control and Management of Media Streams 198 Kernel Transport Ne
13、twork 208.1 Messaging Layer. 208.2 Transport Layer. 208.3 DPE requirements. 219 DPE Interoperability. 219.1 Interoperability Framework 229.2 DPE extensions to CORBA 2 interoperability . 2210 Engineering services provided by the DPE kernel . 2310.1 Introduction. 2410.2 Approach to real-time . 2410.3
14、Requirements on the execution model 2510.4 Modularity requirements. 2510.4.1 Flexible DPE architecture. 2510.4.2 Multi-protocol support 2610.4.3 Generic communication scheme. 2610.4.4 Support for flexible binding 2710.5 Functional requirements . 2710.5.1 Support for stream interfaces 2710.5.2 Multit
15、hreading support . 2710.5.3 A flexible event-to-thread mapping 2810.5.4 Concurrency management 2810.5.5 Generic scheduling scheme 2910.5.6 Time service 2910.6 Non-functional requirements 2910.6.1 Object granularity . 2910.6.2 Small memory footprint 3010.6.3 Documented time behaviour. 3010.7 Multiple
16、 Interfaces 3011 Object Services . 3111.1 Introduction. 3112 Bibliography . 32Annex A - Business modelling concepts . 34ITU-T Z.600 (11/2000) Prepublished version 3Annex B - Engineering modelling concepts 40Appendix I - Object life cycle scenario . 43Appendix II - Flexible binding. 44Appendix III -
17、Issues for the support of stream interfaces. 45ITU-T Z.600 (11/2000) Prepublished version 41 SummaryThis Recommendation describes the Distributed Processing Environment (DPE) Architecture,which represents the run-time environment for telecommunication and information services andapplications.The pur
18、pose of the DPE Architecture is to provide detailed technical requirements leading tospecifications, both to help the DPE vendors to develop their products and the application developerto understand the infrastructure support that the DPE provides.The material herein is based on work done in the TIN
19、A Consortium by the TINA core team andseveral auxiliary projects in the member companies of TINA-C, supporting the core team.The Recommendation contains: an explanation of the relationship between modelling concepts so far as such a relationshipneeds to be concerned in the computing architecture; a
20、description of the Kernel Transport Network (KTN) which is the DPE analogue of thetelecommunications signalling system; an interoperability framework for the DPE; requirements for the DPE kernel services.A number of DPE engineering object services can be identified, that support the execution oftele
21、communication services. These DPE object services are identified and associated to thefunctions and transparencies of the Reference Model for Open Distributed Processing (RM-ODP).Detailed requirements on the DPE object services and their specifications are for further study.The DPE, the DPE object s
22、ervices and the applications deployed on a DPE need to be managed.What are the requirements on management, and how can management of these entities beaccomplished is also for further study.Not all DPE kernel services identified in this Recommendation are required for all applications.DPE profiles th
23、at support different kinds of services and applications need to be defined. Theseprofiles need to specify which kernel services are mandatory for a given profile. The definition ofDPE profiles and their use are for further study. The DPE must support quality of service (QoS) asneeded by the services
24、 and applications. How this is accomplished by the DPE is for further study.2ScopeThis Recommendation specifies the Distributed Processing Environment (DPE) which supports theexecution of distributed telecommunication applications. The DPE can be regarded as theinfrastructure on which distributed te
25、lecommunications applications such as multimedia andreal-time applications can execute.This Recommendation provides the basic requirements and functionality for the DPE to support theexecution of distributed telecommunications applications. Any distributed telecommunicationsapplication designed acco
26、rding to RM-ODP will benefit from using the DPE as a platform. TheDPE itself is based on the RM-ODP concepts and principles (2 and 3).RM-ODP specifies a viewpoint (on a system) as a form of abstraction achieved using a selected setof architectural concepts and structuring rules, in order to focus on
27、 particular concerns within asystem. The RM-ODP viewpoints are: enterprise viewpoint; information viewpoint;ITU-T Z.600 (11/2000) Prepublished version 5 computational viewpoint; engineering viewpoint; technology viewpoint.This Recommendation focuses on the RM-ODP engineering viewpoint. It constitute
28、s aspecialization and refinement of the RM-ODP engineering language to take into account specificrequirements from the telecommunication domain.RM-ODP specifies distribution transparency as the property of hiding from a particular user thepotential behaviour of some parts of a distributed system. Th
29、e RM-ODP distribution transparenciesare: access transparency; failure transparency; location transparency; migration transparency; relocation transparency; replication transparency; persistence transparency; transaction transparency.RM-ODP specifies functions to support Open Distributed Processing.
30、The RM-ODP functions are: management functions; coordination functions; repository functions; security functions.The RM-ODP distribution transparencies and the ODP functions are associated with DPE kernelservices and object services. This Recommendation uses the engineering functions as a basis and,
31、where appropriate, refines them or specializes them for the DPE.The DPE adopts OMG CORBA 2 as the prime technology base and thus the CORBA commonobject services are incorporated where appropriate in the DPE.In particular, this Recommendation encourages the study of Real-Time CORBA 13, since thisOMG
32、specification satisfies already a number of requirements identified in this Recommendation.2.1 PurposeThe purpose of the DPE Architecture is to provide detailed technical requirements leading tospecifications, both to help the DPE vendors to develop their products, and the applicationdeveloper to un
33、derstand the infrastructure support that the DPE provides. The stated requirementsare based on validated results from implementation projects.In summary this Recommendation contains: detailed technical requirements; statements of required functionality.ITU-T Z.600 (11/2000) Prepublished version 62.2
34、 ObjectiveThe objective of this Recommendation is to provide an abstract description of the DPE.Implementations of the DPE have to support RM-ODP compliant applications as developedaccording to RM-ODP concepts and methodology. This abstract description of the DPE isimplementation independent and sho
35、uld be used by DPE platform vendors as a reference forconstructing DPE compliant platforms.2.3 Non-objectivesThis Recommendation describes services that are supposed to be present in many DPEimplementations. It provides descriptions of these services without indicating how those servicesshould be co
36、mbined.Furthermore this Recommendation does not restrict the actual implementation of the DPE in anyway.3 Normative ReferencesThe following Recommendations and International Standards contain provisions, which throughreference in this text constitute provisions of this Recommendation. At the time of
37、 publication, theeditions indicated were valid. All Recommendations and Standards are subject to revision, andparties to agreements based on this Recommendation are encouraged to investigate the possibilityof applying the most recent edition of the Recommendations and Standards listed below. IEC and
38、ISO maintain registers of currently valid International Standards. The TelecommunicationStandardization Bureau of ITU maintains a list of currently valid ITU-T Recommendations.3.1 Identical Recommendations | International Standards1 ITU-T Recommendation X.901 (1997) | ISO/IEC 10746-1:1998, Informati
39、on technology -Open Distributed Processing - Reference Model: Overview.2 ITU-T Recommendation X.902 (1995) | ISO/IEC 10746-2:1996, Information technology -Open Distributed Processing - Reference Model: Foundations.3 ITU-T Recommendation X.903 (1995) | ISO/IEC 10746-3:1996, Information technology -Op
40、en Distributed Processing - Reference Model: Architecture.4 ITU-T Recommendation Z.130 (02/99) - ITU object definition language. .5 ITU-T Recommendation X.931 (06/99) - Information technology - Open distributedprocessing - Protocol support for computational interactions.3.2 Other SpecificationsThe e
41、dition of CORBA 2 indicated below was valid at the time of publication of thisRecommendation. CORBA 2 is subject to revision, and parties to agreements based on thisRecommendation are encouraged to investigate the possibility of applying later editions ofCORBA 2 when they become available.6 OMG, The
42、 Common Object Request Broker: Architecture and Specification, Revision 2.4:October 2000.ITU-T Z.600 (11/2000) Prepublished version 74 DefinitionsFor the purposes of this Recommendation, the following definitions apply.4.1 Terms defined in the ODP Reference Model: FoundationsThis Recommendation make
43、s use of the following terms defined in ITU-T Recommendation X.902:a) architecture (of a system);b) domain;c) interface;d) object;e) template;f) thread.4.2 Terms defined in the ODP Reference Model: ArchitectureThis Recommendation makes use of the following terms defined in ITU-T Recommendation X.903
44、:a) binder;b) capsule;c) channel;d) checkpoint;e) cluster;f) kernel (nucleus);g) node;h) stub.4.3 Definitions for Distributed Processing Environment ArchitectureThis Recommendation makes use of the following terms:Business Administrative Domain: A business administrative domain is defined by therequ
45、irements of one or more business roles and is governed by a single business objective.Business Role: The expected function performed by a stakeholder in a telecommunicationsbusiness environment.Communication API: The application programming interface through which the communicationservices are acces
46、sibleDPE (Distributed Processing Environment): The DPE is the infrastructure that provides theexecution environment, including distribution transparencies, for distributed applications in asystem. The DPE provides a distribution transparent view to its users. The users of the DPE are theapplication
47、and service designers and developers. The DPE consists of a collection of DPE nodesthat are interconnected.DPE API: The application programming interface through which the DPE services are accessible.DPE reference point: The engineering view of a reference point.Engineering Computational Object (eCO
48、): An eCO is the engineering representation of acomputational object (one-to-one correspondence), which encapsulates state/data and processing.ITU-T Z.600 (11/2000) Prepublished version 8Engineering service: Engineering services support the DPE distribution transparencies. There are anumber of engin
49、eering services that are required by a wide range of applications (e.g. repository,object adaptor) and are fundamental for the construction of applications that execute on the DPE.Generic Inter-ORB Protocol (GIOP): The GIOP is a messaging protocol used for objectcommunication between different DPE nodes. The GIOP is specified in 6.Internet Inter-ORB Protocol (IIOP): The IIOP is the mapping of the GIOP to TCP/IP. The IIOPis specified in 6.Inter-domain Reference Point: Same as Reference Point. Unless otherwise stated in this
