SIST ETS 300 200 E1:2003

• Abstract:

  DE/NA-012205

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.080 - Integrated Services Digital Network (ISDN)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI ETS 300 200 ed.1 (1994-12) - Integrated Services Digital Network (ISDN); Call Forwarding Unconditional (CFU) supplementary service; Service description

SIST ETS 300 200 E1:2003 is the Slovene version of ETS 300 200 Edition 1 from ETSI for the Integrated Services Digital Network (ISDN) Call Forwarding Unconditional (CFU) supplementary service. It gives the stage 1 service description from the user’s point of view, showing how calls are redirected, what the served user, calling user, and forwarded-to user are told, and how the service behaves in public ISDN and private ISDN interworking.

What does SIST ETS 300 200 E1:2003 specify?

SIST ETS 300 200 E1:2003 specifies the CFU supplementary service for pan-European ISDN. It covers the service model, operating procedures, interworking, and interaction with other supplementary services.

The standard’s structure is straightforward:

• Clause 1 sets the scope.
• Clause 2 lists normative references.
• Clause 3 defines the key terms.
• Clause 4 gives symbols and abbreviations.
• Clause 5 describes the service.
• Clause 6 covers normal and exceptional procedures.
• Clause 7 addresses intercommunication considerations.
• Clause 8 covers interactions with other supplementary services.

In practice, this means the document tells service providers and implementers what the service must do at the user level, while leaving protocol and switching details to later-stage standards.

What are the key requirements of SIST ETS 300 200 E1:2003?

SIST ETS 300 200 E1:2003 defines CFU as a network service that redirects calls addressed to the served user’s ISDN number to another user. The served user’s outgoing calls are not affected, and forwarding continues regardless of the served user’s status.

Service model and subscription options

Clause 5 and clause 6 allow CFU to be offered on basic access or primary rate access, either for the whole access or per ISDN number. The service can also apply to all basic services or only selected basic services.

Table 1 defines subscription options for notification and identity presentation. In practice, these options decide whether the served user is told that forwarding is active, whether the calling user is told that forwarding happened, and whether the forwarded-to user sees the served user’s ISDN number.

Activation, deactivation, and interrogation

Clause 6 requires the served user to provide the forwarded-to user’s ISDN number when activating CFU, and optionally a subaddress. The service provider may verify the forwarded-to number before accepting activation.

Deactivation and interrogation follow similar access rules. For access-wide subscriptions or a single ISDN number, the served user does not need to repeat the number. This matters because implementations must handle both whole-access and per-number administration cleanly.

Call handling and diversion limits

Clause 6 limits the total number of diversions in a call chain to five, counting all types of diversion. CFU takes effect without offering the call to the served user, and notifications can be passed to the served user, the forwarded-to user, and sometimes the calling user.

If the call cannot be completed to the forwarded-to user, the call is terminated or returned to the earlier diverting user according to the call history. This prevents indefinite forwarding loops and keeps call control predictable.

Exceptional cases and rejection rules

Clause 6 also lists rejection cases, such as invalid served-user identification, missing information, unsupported all-ISDN-numbers operation, an invalid forwarded-to number, or use of a special service number. The network informs only the terminal that made the request.

Interworking and other services

Clause 7 keeps the diversion limit in force across private ISDN and public ISDN interworking, and notes that number or service information may be lost when it crosses a network that does not support these functions. Clause 8 shows where CFU has precedence or no impact on other supplementary services such as call waiting, call forwarding busy, call forwarding no reply, call deflection, CLIP, CLIR, CUG, freephone, MCI, MSN, subaddressing, and user-to-user signalling.

What terms does SIST ETS 300 200 E1:2003 define?

• Integrated Services Digital Network (ISDN) - The network environment to which the CFU service applies.
• Call Forwarding Unconditional (CFU) - The supplementary service that redirects calls immediately and without condition.
• served user - The user who subscribes to CFU and whose calls are redirected.
• forwarded-to user - The user to whom the call is redirected.
• user A - The calling user whose call is subject to diversion.
• user B - The served user when the call is handled by CFU.
• user C - The forwarded-to user in a CFU call chain.
• diversion - The general family of call redirection functions, including forwarding and deflection.

Who uses SIST ETS 300 200 E1:2003?

SIST ETS 300 200 E1:2003 is used by ISDN service providers, network planners, and equipment implementers who need to support CFU correctly. It is also relevant to private ISDN operators, interconnection engineers, and quality or conformance teams checking how forwarding, notifications, and rejection cases behave in service.

The document is especially useful when configuring subscriptions, verifying interworking between networks, and documenting how forwarded calls should appear to the calling and forwarded-to users.

What changed in SIST ETS 300 200 E1:2003 from the previous edition?

SIST ETS 300 200 E1:2003 corresponds to ETS 300 200 Edition 1.

Which standards are used with SIST ETS 300 200 E1:2003?

• CCITT Recommendation I.130 - Gives the three-stage method for describing telecommunication services; this standard uses that structure.
• CCITT Recommendation I.112 - Provides ISDN vocabulary used for terms such as ISDN, basic service, and basic access.
• CCITT Recommendation E.164 - Defines numbering and address structure for ISDN numbers and subaddresses.
• CCITT Recommendation I.210 - Defines supplementary service principles used for the term supplementary service.
• CCITT Recommendation Q.9 - Supplies switching and signalling terminology, including basic access and primary rate access.
• ETS 300 204 - Covers the stage 2 aspects for CFU.
• ETS 300 207 - Covers the stage 3 aspects for CFU.

What does the SIST ETS 300 200 E1:2003 document contain?

SIST ETS 300 200 E1:2003 contains the service description, procedural rules, interworking notes, and service interactions for CFU. Table 1 sets out the subscription options that control notification and identity presentation. Clause 6 gives the activation, deactivation, interrogation, and rejection procedures, while clause 8 describes how CFU behaves with other supplementary services.

The document is written for service behavior and implementation planning, not for testing. It states that conformance is achieved through the stage 3 standards for the relevant equipment, and it does not provide a test method for this stage 1 specification.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digitalno omrežje z integriranimi storitvami (ISDN) – Dopolnilna storitev: brezpogojna podaja klica (CFU) – Opis storitveIntegrated Services Digital Network (ISDN); Call Forwarding Unconditional (CFU) supplementary service; Service description33.080Digitalno omrežje z integriranimi storitvami (ISDN)Integrated Services Digital Network (ISDN)ICS:Ta slovenski standard je istoveten z:ETS 300 200 Edition 1SIST ETS 300 200 E1:2003en01-december-2003SIST ETS 300 200 E1:2003SLOVENSKI
STANDARD
EUROPEANETS 300 200TELECOMMUNICATIONDecember 1994STANDARDSource: ETSI TC-NAReference: DE/NA-012205ICS:33.080Key words:ISDN, supplementary serviceIntegrated Services Digital Network (ISDN);Call Forwarding Unconditional (CFU) supplementary serviceService descriptionETSIEuropean Telecommunications Standards InstituteETSI SecretariatPostal address: F-06921 Sophia Antipolis CEDEX - FRANCEOffice address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCEX.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail].: [phone] - Fax: [phone]Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and theforegoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1994. All rights reserved.SIST ETS 300 200 E1:2003

Page 2ETS 300 200: December 1994Whilst every care has been taken in the preparation and publication of this document, errors in content,typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to"ETSI Editing and Committee Support Dept." at the address shown on the title page.SIST ETS 300 200 E1:2003

Page 3ETS 300 200: December 1994ContentsForeword.51Scope.72Normative references.73Definitions.84Symbols and abbreviations.95Description.96Procedures.96.1Provision and withdrawal.96.2Normal procedures.106.2.1Activation, deactivation and registration.106.2.1.1Activation.106.2.1.2Deactivation.116.2.1.3Registration.126.2.2Erasure.126.2.3Invocation and operation.126.2.3.1Served user's view.126.2.3.2Forwarded-to user's view.136.2.3.3Calling user's view.136.2.4Interrogation.146.3Exceptional procedures.156.3.1Activation, deactivation and registration.156.3.1.1Activation.156.3.1.2Deactivation.166.3.1.3Registration.166.3.2Erasure.166.3.3Invocation and operation.176.3.4Interrogation.177Intercommunication considerations.177.1Interworking with non-ISDNs.187.2Interworking with private ISDN.188Interaction with other supplementary services.188.1Advice of charge services.188.1.1Charging information at call set-up time.188.1.2Charging information during the call.198.1.3Charging information at the end of the call.198.2Call waiting.198.3Call hold.198.4Explicit call transfer.198.5Number identification services.198.5.1Calling line identification presentation.198.5.2Calling line identification restriction.198.5.3Connected line identification presentation.208.5.4Connected line identification restriction.208.6Closed user group.208.7Completion of calls to busy subscribers.208.8Conference services.218.8.1Conference call, add-on.218.8.2Meet-me conference.21SIST ETS 300 200 E1:2003

Page 4ETS 300 200: December 19948.9Direct dialling in.218.10Diversion services.218.10.1Call forwarding unconditional.218.10.2Call forwarding busy.218.10.3Call forwarding no reply.218.10.4Call deflection.218.11Freephone.228.12Malicious call identification.228.13Multiple subscriber number.228.14Subaddressing.228.15Terminal portability.228.16Three party.228.17User-to-user signalling.23History.24SIST ETS 300 200 E1:2003

Page 5ETS 300 200: December 1994ForewordThis European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA)Technical Committee of the European Telecommunications Standards Institute (ETSI).In accordance with CCITT Recommendation I.130 [1], the following three level structure is used todescribe the supplementary telecommunications services as provided by European publictelecommunications operators under the pan-European Integrated Services Digital Network (ISDN):-Stage 1:is an overall service description, from the user's standpoint;-Stage 2:identifies the functional capabilities and information flows needed to support theservice described in stage 1; and-Stage 3:defines the signalling system protocols and switching functions needed to implementthe service described in stage 1.This ETS details the stage 1 aspects (overall service description) for the Call Forwarding Unconditional(CFU) supplementary service. The stage 2 and stage 3 aspects are detailed in ETS 300 204 (1994) andETS 300 207 (1994), respectively.Proposed transposition datesDate of latest announcement of this ETS (doa):31 March 1995Date of latest publication of new National Standardor endorsement of this ETS (dop/e):30 September 1995Date of withdrawal of any conflicting National Standard (dow):30 September 1995SIST ETS 300 200 E1:2003

Page 6ETS 300 200: December 1994Blank pageSIST ETS 300 200 E1:2003

Page 7ETS 300 200: December 19941ScopeThis standard defines the stage one of the Call Forwarding Unconditional (CFU) supplementary servicefor the Pan-European Integrated Services Digital Network (ISDN) as provided by European publictelecommunications operators. Stage one is an overall service description from the user's point of view,but does not deal with the details of the human interface itself (see CCITT Recommendation I.130 [1]).This standard defines the interworking requirements of private ISDNs with the public ISDN.In addition this standard specifies the base functionality where the service is provided to the user via aprivate ISDN.This standard does not specify the additional requirements where the service is provided to the user via atelecommunications network that is not an ISDN but does include interworking requirements of othernetworks with the public ISDN.Charging principles are outside the scope of this standard.Interaction with supplementary services not listed in clause 8 are outside the scope of this standard.The CFU supplementary service enables a served user to have the network redirect to another user callswhich are addressed to the served user's ISDN number. The CFU supplementary service may operate onall calls, or just those associated with specified basic services. The served user's ability to originate calls isunaffected by the CFU supplementary service. After the CFU supplementary service has been activated,calls are forwarded independent of to the status of the served user.The CFU supplementary service is applicable to all circuit-switched telecommunication services.This standard is applicable to the stage two and stage three standards for the ISDN CFU supplementaryservice. The terms "stage two" and "stage three" are also defined in CCITT Recommendation I.130 [1].Where the text indicates the status of a requirement (i.e. as strict command or prohibition, as authorizationleaving freedom, as a capability or possibility), this shall be reflected in the text of the relevant stage twoand stage three standards.Furthermore, conformance to this standard is met by conforming to the stage three standards with thefield of application appropriate to the equipment being implemented. Therefore, no method of testing isprovided for this standard.2Normative referencesThis standard incorporates, by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text and the publications are listedhereafter. For dated references, subsequent amendments to, or revisions of, any of these publicationsapply to this standard only when incorporated in it by amendment or revision. For undated references thelatest edition of the publication referred to applies.[1]CCITT Recommendation I.130 (1988): "Method for the characterization oftelecommunication services supported by an ISDN and network capabilities ofan ISDN".[2]CCITT Recommendation I.112 (1988): "Vocabulary of terms for ISDNs".[3]CCITT Recommendation E.164 (1991): "Numbering plan for the ISDN era".[4]CCITT Recommendation I.210 (1988): "Principles of telecommunicationservices supported by an ISDN and the means to describe them".[5]CCITT Recommendation Q.9 (1988): "Vocabulary of switching and signallingterms".SIST ETS 300 200 E1:2003

Page 8ETS 300 200: December 19943DefinitionsFor the purposes of this standard, the following definitions apply:Integrated Services Digital Network (ISDN): See CCITT Recommendation I.112 [2], § 2.3, definition308.(basic) service; telecommunication service: See CCITT Recommendation I.112 [2], § 2.2, definition201.user A: The calling user in a call which is subject to diversion.user B: The served user when a call (from user A) is subject to the CFU supplementary service.NOTE:In the context of multiple diversions, a suffix is used, e.g. 1, 2, . n, n+1, . m, todenote the successive diverting users. For example, user B3 is also the diverted-touser with respect to the diversion applied at user B2.user C: The forwarded-to user in a call which is subject to the CFU supplementary service. In the case ofa call which is subject to multiple diversions, user C is the forwarded-to user with respect to the final callforwarding.diverted-to user: A user to whom a call is redirected as a result of diversion.supplementary service: See CCITT Recommendation I.210 [4], § 2.4.ISDN number: A number conforming to the numbering plan and structure specified in CCITTRecommendation E.164 [3].basic access: See CCITT Recommendation Q.9 [5], § 1, definition 1551.primary rate access: See CCITT Recommendation Q.9 [5], § 1, definition 1552.address: see CCITT Recommendation E.164 [3], § 12.subaddress: See CCITT Recommendation E.164 [3], § 12.2.served user: The user to whom the CFU supplementary service is provided.forwarded-to user: A user to whom the call is redirected as a result of forwarding.(call) forwarding: A general term applied to any functionality whereby a call is redirected automatically bythe service provider to another user. The forms of forwarding are: unconditional, whereby all calls areredirected; busy, whereby calls encountering busy are redirected; and, no reply, whereby calls which arenot answered within a time period are redirected.diversion: A general term which includes all forms of forwarding, and includes deflection whereby callsare redirected by the user instead of being answered.basic call procedures: The procedures by which a call (as an instance of a basic telecommunicationservice) is established and terminated.diverting user: A user for whom the call is subjected to diversion.SIST ETS 300 200 E1:2003

Page 9ETS 300 200: December 19944Symbols and abbreviationsCFUCall Forwarding UnconditionalISDNIntegrated Services Digital NetworkPSTNPublic Switched Telephone Network5DescriptionThe CFU supplementary service shall be available to users who are connected to the network via a basicaccess or a primary rate access.The CFU supplementary service enables a served user to have the network redirect to another user callswhich are addressed to the served user's ISDN number. The CFU supplementary service may operate onall calls, or just those associated with specified basic services. The served user's ability to originate calls isunaffected by the CFU supplementary service. After the CFU supplementary service has been activated,calls are forwarded independent of the status of the served user.As a service provider option, a subscription option can be provided to enable the served user to receive anindication that the CFU supplementary service has been activated. This indication shall be provided whenthe served user originates a call if the CFU supplementary service has been activated for the serveduser's ISDN number and for the basic service requested for the call.The maximum number of diversions permitted for each call is a service provider option with an upper limitof five diversions. When counting the number of diversions, all types of diversion are included.6Procedures6.1Provision and withdrawalThe CFU supplementary service shall be provided after prior arrangement with the service provider.As a service provider option, the CFU supplementary service can be provided on a per ISDN numberbasis, or the CFU supplementary service can apply to the whole access. If a service provider offers bothof these options, then it shall be a subscription option to choose which of these options applies.In addition, the CFU supplementary service (including options) can be subscribed to for all basic servicessubscribed to by the user, or as a service provider option, the user can identify particular basic service(s)for which the CFU supplementary service shall apply.As a service provider option, the service can be offered with one or more of four subscription options,which can apply separately to each basic service subscribed to. If the CFU supplementary service isprovided on a per ISDN number basis, then these options can apply separately to each ISDN number. Foreach subscription option, only one value can be selected. Subscription options are summarized in table 1.SIST ETS 300 200 E1:2003

Page 10ETS 300 200: December 1994Table 1Subscription optionsValueServed user receives notificationthat the call has been forwarded-no-yesCalling user receives notificationthat the call has been forwarded-no-yes, without the ISDNnumber of the forwarded-touser-yes, with the ISDN number ofthe forwarded-to userServed user receives notificationthat the CFU supplementary serviceis currently activated-no-yesThe served users ISDN number canbe presented to the forwarded-touser-no-yesAs a service provider option, a subscription option can be offered to served users, to enable the CFUsupplementary service to be activated, deactivated and interrogated for all ISDN numbers on the sameaccess. ISDN numbers for which the CFU supplementary service is not subscribed to shall not beaffected.The CFU supplementary service shall be withdrawn by the service provider upon request of the subscriberor for service provider reasons.6.2Normal procedures6.2.1Activation, deactivation and registration6.2.1.1ActivationThe served user shall supply the following information when requesting the activation of the CFUsupplementary service:-the ISDN number of the forwarded-to user, which can be accompanied by a subaddress foradditional identification of the forwarded-to user; and-information as to whether the activation of the CFU supplementary service is for all basic servicesto which the CFU supplementary service applies, or for a specific basic service out of the basicservices to which the CFU supplementary service applies.When subscription applies on a per ISDN number basis and more than one ISDN number is allocated tothe access, then:-the served user shall also supply the ISDN number for which the activation of the CFUsupplementary service shall apply, or;-as a service provider option, the served user can, if subscribed to, indicate that the activation of theCFU supplementary service shall apply for all ISDN numbers for which the CFU supplementaryservice is subscribed to. In this case, this activation shall replace any previous activation of the CFUsupplementary service which may be in force on individual ISDN numbers on the access, for thebasic services indicated at activation.SIST ETS 300 200 E1:2003

Page 11ETS 300 200: December 1994When subscription applies for the whole access, or only one ISDN number is allocated to the access, theserved user need not provide an ISDN number to identify the served user. If the served user includes anISDN number allocated to that access, or indicates that the activation of the CFU supplementary serviceshall apply to all ISDN numbers (if this functionality is offered by the service provider and subscribed to bythe served user) then the ISDN number, or the indication of all ISDN numbers, shall be ignored. Activationof the CFU supplementary service shall proceed as normal.The served user can separately activate the CFU supplementary service for each basic service to whichthe CFU supplementary service applies and thereby request a different ISDN number and/or subaddressto identify the forwarded-to user for each basic service to which the CFU supplementary service applies.When the CFU supplementary service is activated for all basic services, this activation shall replace anyprevious activation of the CFU supplementary service which may be in force on individual basic services.Verification of the ISDN number of the forwarded-to user can be carried out before accepting the requestto activate the CFU supplementary service. This verification can be limited, e.g. a simple check of theISDN number of the forwarded-to user to see if the ISDN number is within the allowed number range.When the served user's request to activate the CFU supplementary service is accepted, the serviceprovider shall inform the served user. The information shall include the address of the forwarded-to userto whom the served user has activated the CFU supplementary service. All affected users shall beinformed.6.2.1.2DeactivationThe CFU supplementary service can be deactivated in any of the following ways:-the served user can request the deactivation of the CFU supplementary service for individual basicservices. The service provider shall inform the served user that the previous activation of the CFUsupplementary service has been deactivated. All affected users shall be informed;-the served user can request the deactivation of the CFU supplementary service for all basicservices. The service provider shall inform the served user that the previous activation of the CFUsupplementary service has been deactivated. All affected users shall be informed;-the served user can request the activation of the CFU supplementary service indicating a basicservice for which the CFU supplementary service has already been activated. This shall replace theprevious information registered for that basic service. In this case, users shall not be specificallyinformed of the deactivation. The procedures of subclause 6.2.1.1 for informing the served userapply;-the served user can request the activation of the CFU supplementary service for all basic services.This shall replace the information registered for all of the basic services for which the CFUsupplementary service has already been activated. In this case, users shall not be specificallyinformed of the deactivation. The procedures of subclause 6.2.1.1 for informing the served userapply.When subscription applies on a per ISDN number basis and more than one ISDN number is allocated tothe access, then:-the served user shall also supply the ISDN number for which the deactivation of the CFUsupplementary service shall apply, or;-as a service provider option, the served user can, if subscribed to, indicate that the deactivation ofthe CFU supplementary service shall apply for all ISDN numbers for which the CFU supplementaryservice is subscribed to.SIST ETS 300 200 E1:2003

Page 12ETS 300 200: December 1994When subscription applies for the whole access, or only one ISDN number is allocated to the access, theserved user need not provide an ISDN number to identify the served user. If the served user includes anISDN number allocated to that access, or indicates that the deactivation of the CFU supplementaryservice shall apply to all ISDN numbers (if this functionality is offered by the service provider andsubscribed to by the served user) then the ISDN number, or the indication of all ISDN numbers, shall beignored. Deactivation of the CFU supplementary service shall proceed as normal.6.2.1.3RegistrationRegistration of information is performed on activation of the CFU supplementary service.There are no separate registration procedures for the CFU supplementary service.6.2.2ErasureNot applicable.6.2.3Invocation and operationThe maximum number of diversions for each call shall be limited. The maximum number of diversions is aservice provider option with an upper limit of five diversions for each call. When counting the number ofdiversions, all types of diversions shall be included.6.2.3.1Served user's viewWhen the CFU supplementary service has been activated, then an incoming call to the served user,indicating a basic service for which the CFU supplementary service has been activated, shall beforwarded without being offered to the served user.According to the value of a subscription option, the served user shall be informed that the CFUsupplementary service has been invoked on the call. This information shall be given when the networkoriginates the call to the forwarded-to user.This information shall include:-indication that the CFU supplementary service has been invoked on a call;-the telecommunications service information;-user-to-user information (if any);-the address of the served user;-the address of user A (provided that the served user has subscribed to the calling line identificationpresentation supplementary service and the calling line identification restriction supplementaryservice is not applied).If multiple diversions have occurred, the information shall also include:-the ISDN number of the originally called user;-the ISDN number of the last diverting user;-reason for last diversion (e.g. invocation of the CFU supplementary service).SIST ETS 300 200 E1:2003

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