1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 8 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU/0%.G0G03934%-3G0G0).4%2#/%#4)/.3%26)#%G0G0$%(b) that Recommendation X.210 defines the service conventions for describing the services of the OSIreference model,(c) that Recommendation X.216 defines the Prese
2、ntation Layer service;(d) that Recommendation X.217 defines the Association Control Service;(e) that Recommendation X.218 defines the Reliable Transfer service;(f) that Recommendation X.229 defines the Remote Operations protocol;(g) that there is a need for common Remote Operations support for vario
3、us applications;unanimously declaresthat this Recommendation defines the Remote Operation service and notation of Open Systems Intercon-nection for CCITT Applications as given in the Scope and Field of Application.CONTENTS0 Introduction1 Scope and Field of Application2 References3 Definitions4 Abbre
4、viations5 Conventions6 Remote Operations Model7 Overview of Notation and Service8 Relationship with other Application Service Elements9 Remote Operations Notation10 Service Definition_1Recommendation X.219 and ISO 9072-1 Information Processing Systems - Text Communications - Remote Operations,Part 1
5、: Model, Notation and Service Definition were developed in close collaboratiomn and are technically aligned2 Fascicle VIII.4 - Rec. X.21911 Mapping of Notation to Service12 Sequencing InformationAnnex A - Notation Supporting the Specification of application-service-elements and Application ContextsA
6、nnex B - Guidelines for application Protocol Designers on the Use of ROSE0 IntroductionThis Recommendation defines a notation and the services provided by an application-service-element - theRemote Operations Service Element (ROSE) - to support interactive applications in a distributed open systemse
7、nvironment. This Recommendation is one of a set of Recommendations defining sets of application-service-elementscommonly used by a number of applications.Interactions between entities of a distributed application are modeled as Remote Operations, and defined usinga Remote Operations Notation. A Remo
8、te Operation is requested by one entity; the other entity attempts to perform theRemote Operation and then reports the outcome of the attempt. Remote Operations are supported by the ROSE.This Recommendation is technically aligned with ISO 9072-1.1 Scope and Field of ApplicationThis Recommendation de
9、fines a Remote Operation (RO-) Notation for defining the services provided tointeractive applications. This Recommendation also defines the services provided by the Remote Operation ServiceElement (ROSE) services. The ROSE services are provided by the use of the ROSE protocol (Recommendation X.229)i
10、n conjunction with the Association Control Service Element (ACSE) services (Recommendation X.217) and theACSE protocol (Recommendation X.227), optionally the Reliable Transfer Service Element (RTSE) services(Recommendation X.218) and the RTSE protocol (Recommendation X.228), and the presentation ser
11、vice(Recommendation X.216).No requirement is made for conformance to this Recommendation.2 ReferencesX.200 Reference Model of Open Systems Interconnection for CCITT Applications (see also ISO 7498).X.208 Specification of abstract syntax notation (see also ISO 8824).X.209 Specification of Basic Encod
12、ing Rules for the abstract syntax notation (see also ISO 8825).X.210 Open Systems Interconnection Layer Service Definition Conventions (see also ISO/TR 8509).X.216 Presentation Service Definition for Open Systems Interconnection for CCITT applications (see alsoISO 8822).X.217 Association Control Ser
13、vice Definition for CCITT Applications (see also ISO 8649).X.218 Reliable Transfer: Model and Service Definition (see also ISO 9066-1).X.227 Association Control Protocol Specification for CCITT Applications (see also ISO 8650).X.228 Reliable Transfer: Protocol Specification (see also ISO 9066-2).X.2
14、29 Remote Operations: Protocol Specification (see also ISO 9072-2).3 Definitions3.1 Reference Model DefinitionsThis Recommendation is based on the concepts developed in Recommendation X.200 and makes use of thefollowing terms defined in it:a) Application Layer;Fascicle VIII.4 - Rec. X.219 3b) applic
15、ation-process;c) application-entity;d) application-service-element;e) application-protocol-data-unit;f) application-protocol-control-information;g) Presentation Layer;h) presentation-service;i) presentation-connection,j) session-service;k) session-connection;l) transfer syntax; andm) user-element.3.
16、2 Service Conventions DefinitionsThis Recommendation makes use of the following terms defined in Recommendation X.210:a) service-provider;b) service-user;c) confirmed service;d) non-confirmed service;e) provider-initiated service;f) service-primitive; primitive;g) request (primitive);h) indication (
17、primitive);i) response (primitive); andj) confirm (primitive).3.3 Presentation Service DefinitionsThis Recommendation makes use of the following terms defined in Recommendation X.216.a) abstract syntax;b) abstract syntax name;c) transfer syntax name;d) presentation context.3.4 Association Control De
18、finitionsThis Recommendation makes use of the following terms defined in Recommendation X.217:a) application-association; association;b) application context;c) Association Control Service Element;3.5 Reliable Transfer DefinitionsThis Recommendation makes use of the following terms defined in Recomme
19、ndation X.218:a) Reliable Transfer Service Element.4 Fascicle VIII.4 - Rec. X.2193.6 ROSE DefinitionsFor the purpose of this Recommendation the following definitions apply:3.6.1 association-initiating-application-entity; association-initiatorThe application-entity that initiates the application-asso
20、ciation.3.6.2 association-responding-application-entity; association-responderThe application-entity that responds to the initiation of an application-association by another AE.3.6.3 invoking-application-entity; invokerThe application-entity that invokes the Remote Operation.3.6.4 performing-applica
21、tion-entity ; performerThe application-entity that performs a Remote Operation invoked by the other application-entity.3.6.5 requestorThe part of an application-entity that issues a request primitive for a particular ROSE service.3.6.6 acceptorThe part of an application-entity that receives the indi
22、cation primitive for a particular ROSE service.3.6.7 linked-operationsA set of operations formed by one parent-operation and one or more child-operations.3.6.8 parent-operationAn operation during the execution of which the performer may invoke linked child-operations to beperformed by the invoker of
23、 the parent-operation.3.6.9 child-operationAn operation which might be invoked by the performer of the linked parent-operation during theexecution of the parent-operation, and which is performed by the invoker of the parent-operation.3.6.10 Remote Operations1) A concept and notation supporting the s
24、pecification of interactive communication between application-entities. This includes the Remote Operation Service Element and the mapping of the notation onto theservice primitives of used application-service-elements.2) The set of bind-operations, unbind-operations and operations.3.6.11 RO-notatio
25、nThe notation used for the specification of Remote Operations, defined in this Recommendation.3.6.12 ACSE-userThe application-specific function that performs the mapping of the bind-operation and unbind-operation of theRO-notation onto ACSE.3.6.13 Remote Operation Service ElementThe application-serv
26、ice-element defined in this Recommendation.Fascicle VIII.4 - Rec. X.219 53.6.14 ROSE-providerThe provider of the Remote Operations Service Element services.3.6.15 ROSE-userThe application-specific function that performs the mapping of the operations and errors of the RO-notationonto ROSE.3.6.16 RTSE
27、-userThe application-specific function that performs the mapping of the bind-operation and unbind-operation of theRO-notation onto RTSE.3.6.17 operation-interfaceThe interface within an application entity between the user element and the application service elements,defined as a set of application s
28、ervice element services (Remote Operations) available to the user element in RO-notation.4 AbbreviationsAE application-entityACSE Association Control Service ElementASE application-service-elementAPDU application-protocol-data-unitOSI Open Systems InterconnectionRO (or ROS) Remote OperationsROSE Rem
29、ote Operations Service ElementRT (or RTS) Reliable TransferRTSE Reliable Transfer Service Element5 ConventionsThis Recommendation defines services for the ROSE following the descriptive conventions defined inRecommendation X.210. In 10, the definition of each ROSE service includes a table that lists
30、 the parameters of itsprimitives. For a given primitive, the presence of each parameter is described by one of the following values:blank not applicableM mandatoryU user optionC conditionalO presence is a ROSE service-provider optionIn addition, the notation ( = ) indicates that a parameter value is
31、 semantically equal to the value to its left in thetable.6 Remote Operations ModelIn the OSI environment, communication between application processes is represented in terms ofcommunication between a pair of application entities (AEs) using the presentation service. Communication betweensome applica
32、tion-entities are inherently interactive. Typically, one entity requests that a particular operation beperformed; the other entity attempts to perform the operation and then report the outcome of the attempt. This Section6 Fascicle VIII.4 - Rec. X.219introduces the concept of Remote Operations as a
33、vehicle for supporting interactive applications.The generic structure of an operation is an elementary request/reply interaction. Operations are carried outwithin the context of an application-association.Figure 1/X.219 models this view.FIGURE 1/X.219Remote operations modelOperations invoked by one
34、AE (the invoker) are performed by the other AE (the performer). Operations maybe classified according to whether the performer of an operation is expected to report its outcome:- in case of success or failure (a result reply is returned if the operation is successful, an error reply isreturned if th
35、e operation is unsuccessful);- in case of failure only (no reply is returned if the operation is successful, an error reply is returned if theoperation is unsuccessful);- in case of success only (a result reply is returned if the operation is successful, no reply is returned if theoperation is unsuc
36、cessful);- or not at all (neither a result nor an error reply is returned, whether the operation was successful or not).Operations may also be classified according to two possible operation modes: synchronous, in which theinvoker requires a reply from the performer before invoking another operation;
37、 an asynchronous, in which the invokermay continue to invoke further operations without awaiting a reply.The following Operation Classes are defined:Operation Class 1: Synchronous, reporting success or failure (result or error).Operation Class 2: Asynchronous, reporting success or failure (result or
38、 error).Operation Class 3: Asynchronous, reporting failure (error) only, if any.Operation Class 4: Asynchronous, reporting success (result) only.Operation Class 5: Asynchronous, outcome not reported.The Operation Class of each operation has to be agreed between application entities (e.g. in an Appli
39、cationProtocol Recommendation).In some cases it is useful to group operations into a set of linked-operations which is formed by one parent-operation and one or more child-operations. The performer of the parent-operation may invoke none, one, or morechild-operations during the execution of the pare
40、nt-operation. The invoker of the parent-operation is the performer ofthe child-operations. A child-operation may be a parent-operation of another set of linked-operations in a recursivemanner. Figure 2/X.219 models this concept.Fascicle VIII.4 - Rec. X.219 7FIGURE 2/X.219Linked-operationsAn applicat
41、ion-association defines the relationship between a pair of AEs, and is formed by the exchange ofapplication-protocol-control-information through the use of presentation-services. The AE that initiates an application-association is called the association-initiating AE, or the association-initiator, w
42、hile the AE that responds to theinitiation of an application-association by another AE is called the association-responding AE, or the association-responder. Only the association-initiating AE may release an established application-association.Application-associations are classified by which applica
43、tion-entity is allowed to invoke operations:Association Class 1: Only the association-initiating application entity can invoke operations.Association Class 2: Only the association-responding application entity can invoke operations.Association Class 3: Both the association-initiating and the associa
44、tion-responding application entitiescan invoke operations.Linked-operations require Association Class 3.The Association Class has to be agreed between application-entities (e.g. in an Application ProtocolRecommendation).The functionality of an AE is factored into one user-element and a set of applic
45、ation-service-elements (ASEs).Each ASE may itself be factored into a set of (more primitive) ASEs. The interaction between AEs is described interms of their use of ASEs.The specific combination of a user-element and the set of ASEs which comprise an AE defines theapplication-context.Figure 3/X.219 i
46、llustrates an example of an application-context involving the Remote Operations ServiceElement (ROSE). Note that this figure is not meant to imply that the application is symmetric. Interactive applicationsare often inherently asymmetric, that is, either one or both AEs may be permitted to invoke op
47、erations, and theoperations that either AE may invoke may be different. The rules governing which AE may invoke operations, andwhich operations an AE may invoke, is defined using the RO-notation in an Application Protocol Recommendation,and determines the application-context.The set of ASEs availabl
48、e to the user element of the AE at the operation-interface is defined using the RemoteOperations (RO-) Notation. The RO-notation is based on the macro concept defined in Recommendation X.208. Thecomplexity of a particular set of ASEs is dependent upon the needs of the application, and is not limited
49、 by the RemoteOperations concept.An important characteristic of Remote Operations is that they provide applications with independence fromOSI communication services. Since the notation is based on established object-oriented programming principles,automatic tools can be developed to bind Remote Operations into the execution environment of applications.8 Fascicle VIII.4 - Rec. X.219The ASEs available to the user-element require communication over an application-association. The control ofthat application-association (establishment, release, abort) is performed either by the A
