1、Standard ECMA-180June 1992Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chProtocol for ComputerSupported TelecommunicationsApplications (CSTA) Phase I.Standard ECMA-180June 1992Standardizing Inform
2、ation and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chIW - Ecma-180.doc - 06.01.99 12:14Protocol for ComputerSupported TelecommunicationsApplications (CSTA) Phase I.Brief HistoryThis Standard defines a Protocol for Computer
3、-Supported Telecommunications Applications (CSTA) for OSI Layer 7communication between a computing network and a telecommunications network. This Standard, plus its companionStandard ECMA-179 Services for Computer-Supported Telecommunications Applications, reflects agreements ofECMA member companies
4、 on the first phase of standards for CSTA. Additional phases are anticipated. This Standard isbased on the practical experience of ECMA member companies and represents a pragmatic and widely basedconsensus.This Standard takes its direction from Technical Report ECMA TR/52 Computer-Supported Telecomm
5、unicationsApplications.Adopted as an ECMA Standard by the General Assembly of June 1992.Usage Note regarding removing Year 2000 (Y2K) risksin the CSTA Phase I and Phase II Protocol Standards1 January 1999In both ITU-T Recs. X.208 (ASN.1 1988) and X.680 (ASN.1 1994), the definition of UTCTime, which
6、is used in theCSTA Phase I and Phase II Protocol Standards (ECMA-180 and ECMA-218 respectively), is not Y2K-safe. The Yearfield (the YY field) is represented by a two-digit string, with no accompanying text mandating a Y2K-safeinterpretation.For the CSTA Phase I and Phase II Protocol Standards, the
7、following interpretation of the Year field is mandated :G01 If the YY component is in the range 00-49, the century is determined to be “20“ (i.e. the year is 2000 to 2049);G01 If the YY component is in the range 50-99, the century is determined to be “19“ (i.e. the year is 1950 to 1999).The risk has
8、 been removed in the CSTA Phase III Protocol Standard (ECMA-285) by replacing the references to“UTCTime“ with references to “GeneralizedTime“, which is Y2K-safe.- i -Table of contentsPageSection 1 - General 11Scope 12 Conformance 12.1 Static requirements 12.2 Dynamic requirements 12.3 PICS requireme
9、nt 13 References 24 Definitions 2Section 2 - Protocol Structure for CSTA 35 CSTA service definition model 35.1 CSTA application layer structure 35.2 Remote operations 35.3 The CSTA service response 35.4 Cross referencing of event reports 45.5 Handling of private data 46 Interconnection service bound
10、ary 47 Security 4Section 3 - CSTA Protocol 58 Association management 59 Switching function services 59.1 Alternate call 69.2 Answer call 79.3 Call completion 89.4 Clear call 99.5 Clear connection 109.6 Conference call 119.7 Consultation call 129.8 Divert call 139.9 Hold call 149.10 Make call 159.11
11、Make Predictive call 169.12 Query device 179.13 Reconnect call 189.14 Retrieve call 199.15 Set feature 209.16 Transfer call 2110 Switching function events 2210.1 Call events 2310.1.1 Call cleared 23- ii -10.1.2 Conferenced 2410.1.3 Connection cleared 2510.1.4 Delivered 2610.1.5 Diverted 2710.1.6 Est
12、ablished 2810.1.7 Failed 2910.1.8 Held 3010.1.9 Network reached 3110.1.10 Originated 3210.1.11 Queued 3310.1.12 Retrieved 3410.1.13 Service initiated 3510.1.14 Transferred 3610.2 Feature events 3710.2.1 Call information 3710.2.2 Do not disturb 3810.2.3 Forwarding 3910.2.4 Message waiting 4010.3 Agen
13、t state events 4110.3.1 Logged on 4110.3.2 Logged off 4210.3.3 Not ready 4310.3.4 Ready 4410.3.5 Work not ready 4510.3.6 Work ready 4610.4 Maintenance events 4710.4.1 Back in service 4710.4.2 Out of service event 4810.5 Private events 4811 Computing function services 4911.1 Route request 4911.2 Re-r
14、oute request 5011.3 Route select request 5111.4 Route used request 5211.5 Route end request 5312 Bidirectional services 5412.1 Escape service 5412.2 System status 5513 Status reporting services 5613.1 Monitor start 5613.2 Change monitor filter 5713.3 Monitor stop 5813.4 Snapshot device 59- iii -13.5
15、 Snapshot call 6014 Switching function errors 6115 Switching event cause values 6316 CSTA data types 6416.1 Switching function objects 6516.2 Device identifiers 6616.3 Call and connection identifiers 6816.4 Connection states 6916.5 Status reporting 7016.6 Device and feature types and other parameter
16、s 7316.7 Security service 7716.8 Common extensions 78Annex A - Protocol Implementation Conformance Statement (PICS) Proforma 79- iv -.Section 1 - General1 ScopeThis Standard specifies application protocol data units (APDUs) for the services described in ECMA-179, Services forComputer-Supported Telec
17、ommunications Applications. The field of application of this Standard is the interconnectionof switches and computers in a private telecommunications environment.Section 2 (clause 5 to clause 7 inclusive) describes the concepts underlying the Remote Operations model, notation andservice. Section 3 (
18、clause 8 to clause 16 inclusive) contains CSTA-specific protocol details and forms the main body ofthis Standard.The protocol defined in this Standard operates in the context of an application association. It is assumed that such anapplication association exists via mechanisms that are not defined i
19、n this Standard.2 ConformanceA manufacturer may select any part (one or more operations) of the CSTA Protocol, as specified in this Standard, forimplemention on a system.A system is in conformance with one or more of the CSTA operations if those operations are implemented according tothe definitions
20、 in this Standard.A Protocol Implementation Conformance Statement (PICS) shall be used to specify the operations which are providedby a particular implementation. A PICS shall also specify the parameter options which are used.A system claiming to implement one or more operations specified within thi
21、s Standard shall comply with the relevantrequirements in clauses 5 to 16 inclusive.2.1 Static requirementsA system claiming conformance shall support the transfer syntax (derived from the encoding rules specified inCCITT Rec. X.209) named G03joint-iso-ccitt(2) asn1(1) basic-encoding(1)G04; for the p
22、urpose of generating andinterpreting CSTA protocol information as defined by the abstract syntax “CSTA-ASN.1-Object-Descriptor“ for theoperations supported.2.2 Dynamic requirementsA system claiming conformance shall:i) follow the procedures as specified in this Standard, and in ECMA-179, relevant to
23、 each CSTA operationthat the system claims to implement, andii) satisfy the definitions, as specified in ECMA-179, relevant to each CSTA service that the system claimsto implement.2.3 PICS requirementThe following shall be stated by the implementer when defining a PICS corresponding to an applicatio
24、n orimplementation:i) which CSTA operations, as defined in ECMA-179, are supported by the system for the particularimplementation,ii) which optional parameters are supported by the PDUs belonging to the supported operations, andiii) the types and ranges of values for all the parameters supported.A P
25、ICS Proforma is given in annex A.- 2 -3 ReferencesECMA-138 Security in Open Systems - Data Elements and Service Definitions (1989)ECMA-155 Addressing in Private Telecommunication Networks (1991)ECMA-179 Services for Computer-Supported Telecommunications Applications (CSTA)(1992)ENV 41007 Definitions
26、 of Terms in Private Telecommunications NetworksISO 9545 Open Systems Interconnection - Application Layer StructureCCITT X.208 / ISO 8824 Specification of abstract syntax notationCCITT X.209 / ISO 8825 Specification of basic encoding rules for the abstract syntax notationCCITT X.217 / ISO 8649 Assoc
27、iation control service definitionCCITT X.219 / ISO 9072-1 Remote operations - Part 1: model notation and service definitionCCITT X.227 / ISO 8650 Association control protocol specificationCCITT X.229 / ISO 9072-2 Remote operations - Part 2: protocol specificationCCITT E.164 Numbering plan for ISDNAl
28、l the CCITT Recommendations referenced above are the 1988 (Blue Book) versions.4 DefinitionsCSTA-specific terminology is defined in ECMA-179. For the purposes of this Standard, the following additionaldefinitions, defined elsewhere, shall apply:Remote Operations as per CCITT Rec. X.219Application As
29、sociation as per CCITT Rec. X.217Application Context as per CCITT Rec. X.217Private Telecommunications Network as per CENELEC ENV 41007- 3 -Section 2 - Protocol Structure for CSTA5 CSTA service definition model5.1 CSTA application layer structureThe CSTA application layer structure conforms to the m
30、odel as described in ISO 9545.5.2 Remote operationsThe services of CSTA are modelled as Remote Operations as described in CCITT Rec. X.219. Typically, one entityrequests that a particular operation be performed; the other entity attempts to perform the operation and responds tothe requestor. Consequ
31、ently the operation of the protocol is an elementary request/reply interaction, supportedwithin the OSI application layer, and carried out within the context of an application-association.For some of the CSTA services, the entity to which the request is sent generates a reply which can indicate succ
32、essor failure. For these services, CSTA shall adopt the Operations Class 2, defined in Rec. X.219 as:- Asynchronous, reporting success or failure (result or error).For some of the CSTA services, the entity to which the request is sent generates a reply which can only indicatefailure. For these servi
33、ces, CSTA shall adopt the Operations Class 3, defined in Rec. X.219 as:- Asynchronous, reporting failure (error) only, if any.For some of the CSTA services, particularly the ongoing reporting of events, no reply is generated. For theseservices, CSTA shall adopt the Operations Class 5, defined in Rec
34、. X.219 as:- Asynchronous, outcome not reported.The protocol description for the particular service defines the relevant class of the Operation used for that service.CSTA shall correlate the single response, denoting success or failure, with the originating request by using themechanisms within the
35、ROSE protocol.5.3 The CSTA service responseCSTA employs a generic response mechanism which is, in principle, decoupled from the specifics of the switchingactivity. The following points describe the operation of the CSTA service response:1. Specific services may have an unconfirmed mode where respons
36、es to correct requests are not returned.2. The server shall check the correctness of the request (e.g. syntactical checks) before issuing the response.Incorrect requests shall result in an error response, even in the unconfirmed mode.3. If a response is sent before the action requested by the servic
37、e is completed (i.e. the response is a servicerequest acknowledgement) event reporting may be used to keep track of the subsequent server activity.4. The precise moment at which the response is generated in relation to the switching activity isimplementation and service dependent.i) Some implementat
38、ions may generate the response after checking the correctness of the requestand at the point they initiate the request.ii) Other implementations may delay the response until the service has completed (or isguaranteed to complete). In this case, a failure of the switching request will be reflected in
39、 theresponse.NOTE 1Irrespective of implementation details, when an operation succeeds the same event reports are generatedif the necessary monitoring has been established. As an example, a Held-Event (if selected) is alwaysreported in addition to the response to a successful request (even in those i
40、mplementations that delay the- 4 -response until the Hold operation was complete). In a given context, and with appropriate monitoring inplace, an operation generates the same set of event reports, whether it was invoked manually or withCSTA service requests from the computer.5.4 Cross referencing o
41、f event reportsA computer application process may need to cross reference a CSTAEventReport to one of the following:a) a CSTA Object ID (Call ID or Device ID),b) an earlier Monitor request, orc) one of many Monitor requests (pertaining to the same CSTA Object).For the above scenarios the necessary c
42、ross referencing function may be fulfilled by use of the parameter“MonitorCrossRefID“. The content of MonitorCrossRefID depends upon the context and it may be one of thefollowing: Call ID, StaticDevice ID, or another independently switch-managed static identifier. The independentidentifier may have
43、a unique correlation to either: one device, one call, or one monitor request.The switching system limit on the number of monitor requests on one CSTA Object (Call or Device) is animplementation option. This Standard does not stipulate how many monitor requests on one object are to besupported by the
44、 switch. If using Static Device or Call identifiers the limit can only be one.5.5 Handling of private dataIf an entity receives the parameter CSTAPrivateData, and it can not recognize the information contained, theparameter shall be discarded, and the rest of the message shall be processed.6 Interco
45、nnection service boundaryThe protocol in this Standard is an OSI application layer protocol and uses the Remote Operations protocol defined inCCITT Rec. X.229. The Remote Operations protocol assumes certain services are provided by the underlying layers,and these services are also assumed by the pro
46、tocol for CSTA.7 SecurityThis protocol also provides a mechanism for secure transmission of CSTA PDUs as defined in this Standard. Theparameters that constitute this secure PDU are imported from ECMA-138.- 5 -Section 3 - CSTA Protocol8 Association managementThe protocol in this Standard operates in
47、the context of an application association. It is assumed that such anapplication association exists via mechanisms not defined in this Standard.9 Switching function servicesThis clause defines the protocol for the Switching Function services of CSTA, using ASN.1. Text descriptions of theCSTA service
48、s are provided in ECMA-179.The encoding of the protocol is defined in CCITT Rec. X.209 “ Specification of basic encoding rules for the abstractsyntax notation“.NOTE 2The range of services supported on a particular association is specified in the application context at association time.- 6 -9.1 Alter
49、nate callCSTA-alternate-call iso( 1) identified-organization( 3) icd-ecma( 0012)standard( 0) csta( 180) version1( 1) alternate-call( 1) DEFINITIONS :=BEGINIMPORTSOPERATION, ERROR FROM Remote-Operations-Notation joint-iso-ccitt( 2) remote-operations( 4) notation( 0) - Data Types -ConnectionDetails FROM CSTA-device-feature-types iso( 1) identified-organization( 3) icd-ecma( 0012)standard( 0) csta( 180) version1( 1) device-feature-types(
