5i' SECTION 5 SUPPLEMENTARY SERVICES IN ISDN Recommendation I.250 DEFINITION OF SUPPLEMENTARY SERVICES (Melbourne, 1988) 1 General Recommendation I.210 describes the principles for defining telecommunication services supported by an ISDN including the con- cept of bearer services, teleservices and supplementary services. It also provides the means for the definition and description of such services. The purpose of this Recommendation is to define a recommended set of supplementary services to be used in association with basic bearer services and with basic teleservices. These definitions form the basis for detailed descriptions as given in Recommendations I.251 to I.257, which are used to define the net- work capabilities required. Supplementary services are described by prose definitions and descriptions and by dynamic descriptions following the description method given in Recommendation I.130. The application for supple- mentary services of the attribute technique described in Recommendation I.140 is for further study. Note - Alignment and interworking between user facilities as defined in Recommendations X.2 and X.301 for the provision of data transmission services and the supplementary services in the I.250-Series and interworking in the I.500-Series of Recommenda- tions require further study. 2 List of supplementary services The following set of supplementary services is currently iden- tified and more may be identified in the future: Recommendation I.251 Number Identification supplementary services I.251.1 Direct-Dialling-In (DDI) I.251.2 Multiple Subscriber Number (MSN) I.251.3 Calling Line Identification Presentation (CLIP) I.251.4 Calling Line Identification Restriction (CLIR) I.251.5 Connected Line Identification Presentation (COLP) I.251.6 Connected Line Identification Restriction (COLR) I.251.7 Malicious Call Identification (MCI) (Note) I.251.8 Sub-addressing (SUB) (Note) Recommendation I.252 Call Offering supple- mentary services I.252.1 Call Transfer (CT) I.252.2 Call Forwarding Busy (CFB) I.252.3 Call Forwarding No Reply (CFNR) I.252.4 Call Forwarding Unconditional (CFU) I.252.5 Call Deflection (CD) (Note) I.252.6 Line Hunting (LH) Recommendation I.253 Call Completion sup- plementary services I.253.1 Call Waiting (CW) I.253.2 Call Hold (HOLD) I.253.3 Completion of Calls to Busy Subscribers (CCBS) (Note) Recommendation I.254 Multiparty supplemen- tary services I.254.1 Conference Calling (CONF) I.254.2 Three Party Service (3PTY) Recommendation I.255 Community of Interest supplementary services I.255.1 Closed User Group (CUG) I.255.2 Private Numbering Plan (PNP) (Note) Recommendation I.256 Charging supplementary services I.256.1 Credit Card Calling (CRED) (Note) I.256.2 Advice of Charge (AOC) I.256.3 Reverse Charging (REV) (Note) Recommendation I.257 Additional Information Transfer supplementary service I.257.1 User-to-User Signalling (UUS) Note - This service having been identified now requires further study; its description is not yet included. 3 Association of supplementary services to bearer services and teleservices Table 1/I.250 shows the association of supplementary services to basic bearer services and basic teleservices identified so far. Their provision in a particular ISDN is a network provider's option. Other associations are for further study. Service Recommendations of the F-Series may recommend the individual provision of supplementary services with teleservices, for example, the provision with the telematic services Teletex, Telefax, Mixed Mode, etc. 4 Definitions of supplementary services a) At stage 1 of the description method the ser- vices are described from the user's perspective, but do not concern details of the human interface itself. For example, in Call Waiting there is a statement that the served user "shall be informed" that a call is waiting. It does not specify whether this shall be accom- plished by a bell, a light, a synthesized voice, etc. b) Similarly, the stage 1 service description is independent of the amount of functionality in the user's terminal other than that required to provide the human interface. For exam- ple, the Conference Calling Service description is designed to be independent of whether the conference bridge is in the terminal, in the serving exchange, or elsewhere. c) While the service descriptions are directly applicable to public networks, it is expected that the design of private networks will take these descriptions into account in order to ease the interworking between public and private networks. d) Although reference is made to human users, there is no restriction on a machine or procedures being the user of these supplementary services. Examples include automatic answering terminals, voice announcement systems, etc. e) Combining points a) to d), there is no prohibi- tion against "machines" (e.g. call distributors) that use the CCITT described services and then offer the same or other (e.g. customized) services to their users. f ) Lastly, the "machine" referred to above could, in fact, be an entire private network. H.T. [1T1.250] _______________________________________________________ TABLE 1/I.250 { Association of supplementary services to basic bearer services and to basic teleservices supported by ISDN } _______________________________________________________ | | | | | | | | | | | | | | ___________________________________________________________________________________________________________________________________________________________________ { Teleservices { 64 kbit/s speech demand { { { { Supplementary services Telephony Teletex Telefax 4 Videotex Mixed mode ___________________________________________________________________________________________________________________________________________________________________ Direct-dialling-in X X X X X X X X Multiple subscriber number X X X X X X X X { Calling line identification presentation } X X X b) b) b) X X X X X { Calling line identification restriction } X X X b) b) b) X X X X X { Connected line identification presentation } X X X b) b) b) X X X X X { Connected line identification restriction } X X X b) b) b) X X X X X { Malicious calls identification | ua) } Sub-addressing | ua) Call transfert X X X X Call forwarding busy X X X X Call forwarding no reply X X X X X Call forwarding unconditional X X X X X Call deflection | ua) Line hunting X X X X Call waiting X X X X Call hold X X X X { Completion of calls to busy subscribers | ua) } Conference calling X X X X ___________________________________________________________________________________________________________________________________________________________________ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Table 1/I.250 [1T1.250], p. A L'ITALIENNE H.T. [2T1.250] _________________________________________________ { TABLE 1/I.250 (continued) } _________________________________________________ | | | | __________________________________________________________________________________________________________________________________________________ { Teleservices { 64 kbit/s speech demand { { { { Supplementary services Telephony Teletex Telefax 4 Videotex Mixed mode __________________________________________________________________________________________________________________________________________________ Three party service X X X X Closed user group X X X X X X X X { Private numbering plan | ua) } { Credit card calling | ua) } Advice of charge X X X X X X X X Reserve charging | ua) User-to-user signalling X X X b) b) b) X X X X __________________________________________________________________________________________________________________________________________________ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | X denotes applications of supplementary services identified within each supplementary service description; other associa- tions are for further study. a) This supplementary service is not yet included in the descrip- tions. b) Further study is required on the association of this supplemen- tary service to this circuit mode bearer service. Tableau 1/I.250 [2T1.250], p. 2 A L'ITALIENNE 4.1 Number Identification supplementary services (Recommendation I.251) I.251.1 Direct Dialling In (DDI) is a supplementary service which enables a user to directly call another user on a ISPBX or other private system without attendant intervention. I.251.2 Multiple Subscriber Number (MSN) is a supplementary ser- vice which provides the possibility for assigning multiple ISDN numbers to a single interface. I.251.3 Calling Line Identification Presentation (CLIP) is a sup- plementary service offered to the called party which provides the calling party's ISDN-number, possibly with sub-address information, to the called party. I.251.4 Calling Line Identification Restriction (CLIR) is a sup- plementary service offered to the calling party to restrict presen- tation of the calling party's ISDN-number and sub-address to the called party. I.251.5 Connected Line Identification Presentation (COLP) is a supplementary service offered to the calling party which provides the connected party's ISDN-number to the calling party. I.251.6 Connected Line Identification Restriction (COLR) is a sup- plementary service offered to the connected party to restrict presentation of the connected party's ISDN-number to the calling party. I.251.7 Malicious call identifiction (Definition not yet included, further study is needed). I.251.8 Sub-addressing (Definition not yet included, further study is needed). 4.2 Call Offering supplementary services (Recommendation I.252) I.252.1 Call Transfer is a supplementary service which enables a user to transfer an established (i.e. active) call to a third party. For the original call, the served user may have been either the calling or called party (i.e. it may have been either an incom- ing or outgoing call). I.252.2 Call Forwarding Busy (CFB) is a supplementary service which permits a served user to have the network send to another number all incoming calls for the served user's ISDN number (or just those associated with a specified basic service) which meet busy at the served user's ISDN number. The served user's originat- ing service is unaffected. I.252.3 Call Forwarding No Reply (CFNR) is a supplementary service which permits a served user to have the network send to another number all incoming calls for the served user's ISDN number which meet no reply (or just those associated with a specific basic ser- vice which meet no reply). The served user's originating service is unaffected. I.252.4 Call Forwarding Unconditional (CFU) is a supplementary service which permits a served user to have the network send to another number all incoming calls for the served user's ISDN number (or just those associated with a specified basic service). The served user's originating service is unaffected. If this service is activated, calls are forwarded regardless of the condition of the termination. I.252.5 Call Deflection (Definition not yet included, further study is needed). I.252.6 Line Hunting is a supplementary service which enables incoming calls to a specific ISDN number to be distributed over a group of interfaces. 4.3 Call Completion supplementary services (Recommendation I.253) I.253.1 Call Waiting is a supplementary service which permits a subscriber to be notified of an incoming call (as per Basic Call procedures) with an indication that no interface information chan- nel is available. The user then has the choice of accepting, rejecting or ignoring the waiting call (as per Basic Call pro- cedures). I.253.2 Call Hold is a supplementary service which allows a user to interrupt communications on an existing call/connection and then subsequently, if desired, reestablish communications. I.253.3 Completion of Calls to Busy Subscribers (Definition not yet included, further study is needed). 4.4 Multiparty supplementary services (Recommendation I.254) I.254.1 Conference Calling is an ISDN supplementary service which allows a user to communicate simultaneously with multiple parties, which may also communicate among themselves. I.254.2 Three-Party Service is a supplementary service which enables a user who is active on a call to hold that call, make an additional call to a third party, switch from one call to the other as required (privacy being provided between the two calls), and/or release one call and return to the other. Optionally, the served user could subscribe to an ability to join the two calls together into a three-way conversation. 4.5 Community of Interest supplementary services (Recommendation I.255) I.255.1 Closed User Group (CUG) is a supplementary service which enables users to form groups, to and from which access is res- tricted. A specific user may be a member of one or more CUGs. Members of a specific CUG can communicate among themselves but not, in general, with users outside the group. Specific CUG members can have additional capabilities that allow them to originate calls outside the group, and/or to receive calls from outside the group. Specific CUG members can have additional restrictions that prevent them from originating calls to other members of the CUG, or from receiving calls from other members of the CUG. I.255.2 Private Numbering Plan (Definition not yet included, further study is needed). 4.6 Charging supplementary services (Recommendation I.256) I.256.1 Credit Card Calling (Definition not yet included, further study is needed). I.256.2 Advice of Charge is a supplementary service allowing the user paying for a call to be informed of usage-based charging information. This service may include one or more of the following cases: 1) Charging information at the end of the call. 2) Charging information during a call. 3) Charging information at call setup time. I.256.3 Reverse charging (Definition not yet included, further study is needed). 4.7 Additional information transfer supplementary service (Recommendation I.257) I.257.1 User-to-User Signalling (UUS) is a supplementary service which allows an ISDN user to send/receive a limited amount of information to/from another ISDN user over the signalling channel in association with a call to the other ISDN user. Recommendation I.251 NUMBER IDENTIFICATION SUPPLEMENTARY SERVICES (Melbourne, 1988) The purpose of this Recommendation is to provide the stage 1 description of the method defined in Recommendation I.130 using the means given in Recommendation I.210. Supplementary services are described by a prose definition and description (step 1.1) and by a dynamic description (step 1.3). The application of the attribute technique (step 1.2), as defined in Recommendation I.140, for supplementary services is for further study. This Recommendation describes the following Number Identifica- tion supplementary services: I.251.1 Direct-Dialling-In (DDI) I.251.2 Multiple Subscriber Number (MSN) I.251.3 Calling Line Identification Presentation (CLIP) I.251.4 Calling Line Identification Restriction (CLIR) I.251.5 Connected Line Identification Presentation (COLP) I.251.6 Connected Line Identification Restriction (COLR) I.251.7 Malicious Call Identification (MCI) (Note) I.251.8 Sub-addressing (SUB) (Note) Note - This service having been identified now requires further study, its description is not yet included. 1 I.251.1 - Direct-Dialling-In 1.1 Definition Direct-Dialling-In (DDI) enables a user to directly call another user on an integrated services private branch exchange (ISPBX) or other private system without attendant intervention. 1.2 Description 1.2.1 General description A part of the ISDN number, which is significant to the called user, is passed to that user during call establishment. This sup- plementary service is based on the use of the ISDN number and does not include sub-addressing. Note 1 - A similar method to select a terminal on a passive bus is described in the supplementary service MSN. Note 2 - The caller may or may not find the ISDN number in the public directory. 1.2.2 Specific terminology None. 1.2.3 Qualifications on the applicability to telecommunica- tion services No restrictions. 1.3 Procedures 1.3.1 ProvisionB/Fwithdrawal This service shall be provided/withdrawn after pre-arrangement with the service provider. The service provider shall allocate a set of ISDN numbers. 1.3.2 Normal procedures 1.3.2.1 Activation/deactivation/registration Activation through subscription. 1.3.2.2 Invocation and operation Call initiation procedures are the same as for the basic ser- vice. The calling and called users perceive the same completion procedures as for the basic service, without attendant interven- tion. Upon answer, the calling user is connected to the called user designated by the ISDN number. Note - When the connection from the caller to the ISPBX is established, the called ISPBX might use the connection for call progress signalling transmission. 1.3.3 Exceptional procedures 1.3.3.1 Activation/deactivation/registration Not applicable. 1.3.3.2 Invocation and operation If the called user is busy or does not answer, the procedures for basic calls will apply. If a call is made by sending incomplete address information, the call will be released by time supervision within the public exchange. A corresponding time supervision within the ISPBX may also be convenient. 1.3.4 Alternative procedures 1.3.4.1 Activation/deactivation/registration None identified. 1.3.4.2 Invocation and operation None identified. 1.4 Network capabilities for charging This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that infor- mation. It shall be possible to charge the subscriber accurately for the service. 1.5 Interworking requirements No problems identified. 1.6 Interaction with other supplementary services 1.6.1 Call Waiting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.2 Call Transfer No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.3 Connected Line Identification Presentation For further study. 1.6.4 Connected Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.5 Calling Line Identification Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.6 Calling Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.7 Closed User Group No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.8 Conference Calling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.9 Direct-Dialling-In Not applicable. 1.6.10 Call Diversion (i.e. Call Forwarding) services 1.6.10.1 Call Forwarding Busy No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.10.2 Call Forwarding No Reply No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.10.3 Call Forwarding Unconditional No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.11 Line Hunting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.12 Three-Party Service No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.13 User-to-User Signalling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.14 Multiple Subscriber Number No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.15 Call Hold No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.6.16 Advice of Charge No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 1.7. Dynamic description The dynamic description is as for basic services. 2 I.251.2 - Multiple Subscriber Number 2.1 Definition Multiple Subscriber Number (MSN) provides the possibility for assigning multiple ISDN numbers to a single interface. For example, this service: 1) allows dialling from a line connected to a pub- lic network directly to terminals connected to a basic access which has subscribed to MSN (e.g. in a passive bus configuration); 2) enables the network to determine which ISDN number is applicable on originating calls (e.g. for charging pur- poses, for notification to the called party and application for supplementary services). It is considered: - that some Administrations may not have knowledge or control over what is connected to the basic access, e.g. an NT2 or passive bus; - that Administrations have differing numbering methods; - that common international terminal specifications are desired. 2.2 Description 2.2.1 General description The addressing of terminals on a basic access may be achieved by applying a set of ISDN numbers to the single basic access. When a call with one of these ISDN numbers is delivered, the called number is indicated to the MSN user, either directly or through a mapping by the network. In general, any set of numbers may be sent from the network to the subscriber's equipment during call establishment. However, it is recognized that administrative practices and certain equipment designs may lead to the adoption of restricted numbering sequences, e.g. by relating the last digit(s) of a fixed length ISDN number to the terminals to be connected. The actual method of relating the ISDN number to a particular terminal is a matter of national imple- mentation but may, for example, be done by central intelligence or by distributed intelligence within the terminals. The essential difference between this supplementary service and DDI concerns the length of the number sent to, and processed by, the user's installation. In the DDI situation the user (ISPBX) will be tailored on a per installation basis to receive the partic- ular number of digits necessary to identify the terminals of this user (ISPBX). With the multiple subscriber number supplementary service how- ever, the service provider will fix the length of the number to be transmitted to the user's installation. It may comprise 1 or 2 or 3 of the last digits up to the full ISDN number. This number will be sent to the user network interface. The digit(s) significant for terminal differentiation is/are an integral part of the ISDN numbering scheme. Note - MSN is independent from and does not impose any con- straints on "service indication" and "sub-addressing". 2.2.2 Specific terminology None. 2.2.3 Qualifications on the applicability to telecommunica- tion services No restrictions. 2.3 Procedures 2.3.1 Provision/withdrawal The service shall be provided after pre-arrangement with the service provider. The service provider shall allocate a set of ISDN numbers (not necessarily consecutive). At the option of the service provider, one of these numbers may be designated by the MSN subscriber as the default number for the interface. At the option of the service pro- vider, the user may specify a mapping arrangement between ISDN number and MSN digit(s). 2.3.2 Normal procedures 2.3.2.1 Activation/deactivation/registration Activation through subscription. 2.3.2.2 Invocation and operation The destination number sent by the calling user will be analyzed in the network. If the called user subscribes to this sup- plementary service, the network sends the available part of the ISDN number or at least the relating digit(s): i) identical to that last digit(s) of the ISDN number; or ii) generated by the network on the basis of a mapping process between ISDN number(s) and MSN digit(s). Terminals compatible to the MSN service will react on a call as follows: - if MSN digit(s) equal to their own preadjusted identity is (are) presented, they react to it in a predetermined way; - if there is a set-up message without MSN digit(s), the terminal will interpret it as a normal call. (This may happen if a terminal with MSN capabilities is used on an inter- face, where MSN is not subscribed for.) Terminals not compatible to the MSN service will react to a call as follows: - whether there is (are) MSN digit(s) or not, the call will be interpreted as a normal call. On outgoing calls a terminal compatible with the MSN service may provide the ISDN number (or MSN digits) when placing the call. The network will carry this identity unchanged or will replace the digit(s) by the associated ISDN number. The ISDN number of the cal- ling terminal will then be sent to the called user with the incom- ing call (refer to S 3, CLIP supplementary service). It is possible to allocate one ISDN number to one or more ter- minals. Similarly, one terminal may allow the assignment of one or more than one number. Further, as an administrative option a specific digit or sequence of digits may be allocated to enable all terminals in a point-to-multipoint configuration to react in the same way as they would if the supplementary service MSN were not subscribed to. 2.3.3 Exceptional procedures 2.3.3.1 Activation/deactivation/registration Not applicable. 2.3.3.2 Invocation and operation An ISDN number or MSN digits, generated by a terminal at an interface where MSN is in operation shall be discarded by the net- work unless this number is subscribed to by this interface. A default number may be provided by the network. 2.3.4 Alternative procedures 2.3.4.1 Activation/deactivation/registration None identified. 2.3.4.2 Invocation and operation None identified. 2.4 Network capabilities for charging This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that infor- mation. It shall be possible to charge the subscriber accurately for the service. 2.5 Interworking requirements None identified. 2.6 Interaction with other supplementary services In case of interaction with other supplementary services, these services could be applicable to the individual MSN rather than to the subscriber access. 2.6.1 Call Waiting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.2 Call Transfer No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.3 Connected Line Identification Presentation See COLP (S 5) interaction with MSN. 2.6.4 Connected Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.5 Calling Line Identification Presentation Upon call initiation, if the ISDN number indicated by the MSN user terminal is not subscribed to for the interface, or if no numbering information is indicated, a default number (if designated by the MSN subscriber) or a number unavailable indication is pro- vided to the CLIP user. 2.6.6 Calling Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.7 Closed User Group For further study. 2.6.8 Conference Calling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.9 Direct-Dialling-In No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.10 Call Diversion (i.e. Call Forwarding) services 2.6.10.1 Call Forwarding Busy No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.10.2 Call Forwarding No Reply No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.10.3 Call Forwarding Unconditional No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.11 Line Hunting service For further study. 2.6.12 Three-Party Service No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.13 User-to-User Signalling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.14 Multiple Subscriber Number Not applicable. 2.6.15 Call Hold No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.6.16 Advice of Charge No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 2.7 Dynamic description The dynamic description is as for the basic services. 3 I.251.3 - Calling Line Identification Presentation 3.1 Definition Calling Line Identification Presentation (CLIP) is a supple- mentary service offered to the called party which provides the cal- ling party's ISDN-number, possibly with sub-address information, to the called party. 3.2 Description 3.2.1 General description When CLIP is applicable and activated, the network provides the called party with the number of the calling party at call set-up on all incoming calls. The calling party number may be accompanied by a sub-address. The network should be capable of transmitting at least 15 digits (maximum length of an ISDN number). In addition, if provided by the calling party, the network should be capable of transmitting a sub-address. The network to which the calling party belongs should attempt to ensure that enough digits are transmitted to enable the called party to return the call, based on the calling number presented. 3.2.2 Specific terminology None identified. 3.2.3 Qualifications on the applicability to telecommunica- tion services This supplementary service is applicable to all telecommunica- tion services. It is to be noted that in the Telematic services an exchange of terminal identification (TID) occurs at a higher layer subse- quent to a successful call establishment. For Telematic services this supplementary service shall con- sist only of the access number of the calling party and this shall be provided by the network. For other non-voice services this sup- plementary service is for further study. The presentation of the calling party's ISDN-number by Telematic terminals and by other non-voice terminals is for further study. 3.3 Procedures 3.3.1 Provision/withdrawal CLIP may be provided on a subscription basis or be generally available. CLIP may be withdrawn at the request of the subscriber or by the network provider for administrative reasons. 3.3.2 Normal procedures 3.3.2.1 Activation/deactivation/registration CLIP is activated on provision and deactivated on withdrawal. No information needs to be registered with the network for this supplementary service. 3.3.2.2 Invocation and operation The number presented shall unambiguously identify the access of the calling party. The number presented is either: i) completely provided by the network; ii) completely provided by the calling party; or iii) partially provided by the network with the rest provided by the calling party (e.g. the access number is pro- vided by the network and the additional digits to make the number complete by the calling party). Where either the complete calling number, or part of the cal- ling number is initially provided by the calling party, the network shall check its validity. If this check is successful, then this number is used by the network. For complete calling numbers, this validity check shall determine whether the number is allocated to the access; for partially provided numbers this check shall, for example, determine whether the digits are within the allocated range. 3.3.3 Exceptional procedures 3.3.3.1 Activation/deactivation/registration None identified. 3.3.3.2 Invocation and operation If the network check on a calling party-provided number is unsuccessful, the network will use the default number as the number of the calling party. There are two cases where the calling party number is not presented to the called party: i) when the calling party has an arrangement (see definition of Calling Line Identification Restriction) whereby presentation of his number is not allowed; and ii) when the calling party number is not avail- able, e.g., due to interworking with the analogue telephone network (PSTN). In such cases no number is presented to the called party, but he shall receive an indication that the number of the calling party is unavailable. 3.3.4 Alternative procedures 3.3.4.1 Activation/deactivation/registration None identified. 3.3.4.2 Invocation and operation In some cases where a calling party has an arrangement such that presentation of his number is not allowed, there may be cer- tain categories of called party that have the ability to override this restriction and have the calling number presented. This func- tion is a national option. Problems may occur when the calling party does not belong to the same network as the called party and in the calling party's network the override category does not exist, while, in the called party's network it does. A problem occurs when a calling party who restricts presentation and assumes that his number is never presented, makes a call to a called party who is in the override category. The cases where the override category is applied is a national matter. Depending on bilateral agreement about the application of the override category in country B, and the "presentation not allowed" arrangement of the calling party in country A, country A may or may not deliver the calling line identification to country B. Agreements are also needed with any transit network. 3.4 Network capabilities for charging This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that infor- mation. It shall be possible to charge the subscriber accurately for the service. 3.5 Interworking requirements On calls incoming from some non-ISDN networks, the calling number may be delivered to the destination ISDN without the ability to indicate whether presentation is allowed or not. How the ISDN should behave in this case is for further study. From some other non-ISDN networks, no calling party number may be available to the ISDN and therefore the full number of the cal- ling party cannot be given to the called party who has been pro- vided with CLIP. In this situation a partial number, or a "number unavailable" indication, is given to the called party. As a national option, the originating network shall have the possibility to restrict any information identifying the calling party from being forwarded to another network. If a destination network receives a calling party ISDN number without any indication of presentation allowed or restricted, the destination network (host network) will act according to its own rules and regulations. 3.6 Interaction with other supplementary services 3.6.1 Call Waiting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. If an ISDN user(s) who has subscribed to the Call Waiting ser- vice at his B access, has been given a call waiting indication and has subscribed to the CLIP service, then the calling party's number shall be presented to the ISDN user(s) at B at the time the call waiting indication is given. The presentation of the CLIP informa- tion shall be the same as when the ISDN user(s) at B receives a normal call. 3.6.2 Call Transfer Refer to Recommendation I.252, S 1.6.5, interaction with CLIP. 3.6.3 Connected Line Identification Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.4 Connected Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.5 Calling Line Identification Presentation Not relevant. 3.6.6 Calling Line Identification Restriction The calling line identification will not be presented if the calling user has an arrangement to inhibit the presentation of his number to the called party. The only occasion when a user subscrib- ing to CLIP can take precedence over CLIR is when the user is in an override category. This is a national option. 3.6.7 Closed User Group No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.8 Conference Calling Any party that has subscribed to CLIP will receive the number of a calling conference controller when: - the party is to be included as a "new party" dur- ing the invocation of a conference call; or - the party is being added to an existing confer- ence call. 3.6.9 Direct Dialling In No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.10 Call Diversion (i.e. Call Forwarding) services If an incoming call to the party to which CLIP has been pro- vided has already been forwarded, then the calling party's number should be the number of the original calling party. 3.6.10.1 Call Forwarding Busy Refer to Recommendation I.252, S 2.6.5, interaction with CLIP. 3.6.10.2 Call Forwarding No reply Refer to Recommendation I.252, S 3.6.5, interaction with CLIP. 3.6.10.3 Call Forwarding Unconditional Refer to Recommendation I.252, S 4.6.5, interaction with CLIP. 3.6.11 Line Hunting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. The Line Hunting service occurs before CLIP. The Line Hunting service would first provide a selection of an interface for presen- tation of a call. Once the service selects an interface, normal call processing would occur including the presentation of the cal- ling party's number to a selected interface who has subscribed to CLIP. 3.6.12 Three-Party service No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.13 User-to-User Signalling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.14 Multiple Subscriber Number Refer to S 2.6.5 above, interaction with CLIP. 3.6.15 Call Hold No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.6.16 Advice of Charge No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 3.7 Dynamic description The dynamic description for this service is shown in Figure 1/I.251. 4 I.251.4 - Calling Line Identification Restriction 4.1 Definition Calling Line Identification Restriction (CLIR) is a supplemen- tary service offered to the calling party to restrict presentation of the calling party's ISDN number and sub-address to the called party. 4.2 Description 4.2.1 General description When CLIR is applicable and activated, the originating node provides the destination node with a notification that the calling party's ISDN number and any sub-address information are not allowed to be presented to the called party. In this case no calling party number is included in the call offering to the called party's installation. Note - When CLIR is subscribed to, some network providers may not wish to send the originating identity of the calling customer to other network providers. Figure 1/I.251, p. Figure 1/I.251 (suite), (feuillet 2 sur 2), p. 4.2.2 Specific terminology None identified. 4.2.3 Qualifications on the applicability to telecommunica- tion services None identified, i.e., this supplementary service is applica- ble to all telecommunication services. 4.3 Procedures 4.3.1 Provision/withdrawal CLIR can be provided on a subscription basis or can be gen- erally available. As a network provider option, CLIR can be offered with several subscription options. The options apply separately to each ISDN number. Subscription options are summarized below: Subscription option Values CLIR mode - permanent (active for all calls) - temporary (specified by user per call) Default - presentation restricted (only for temporary mode) - presentation not res- tricted It is a network provider option to specify either or both of the above options for all subscribers, for instance, in an exchange or network. 4.3.2 Normal procedures 4.3.2.1 Activation/deactivation/registration If subscribed to in the permanent mode, CLIR is always activated. If subscribed to on a temporary basis, CLIR is activated upon explicit request for the service, or on default, on a particular call and is deactivated after that call. 4.3.2.2 Invocation and operation If the called party subscribes to Calling Line Identification Presentation and the calling party has CLIR activated, the called party shall receive an indication that the calling party number is not available. 4.3.3 Exceptional procedures 4.3.3.1 Activation/deactivation/registration No exceptional procedures identified. 4.3.3.2 Invocation and operation No exceptional procedures identified. 4.3.4 Alternative procedures 4.3.4.1 Activation/deactivation/registration No alternative procedures identified. 4.3.4.2 Invocation and operation Certain countries may define categories of subscribers that have the ability to override the presentation restriction and have the calling party's ISDN number and any sub-address presented (e.g., the police). The ability to have such an override option is a national matter. When a call originates in one ISDN and terminates in another ISDN and CLIR is applied, the rules and regulations of the destina- tion network (the host network) should apply. For example, if the override category is not applicable in the originating network but it is in the destination network, a call with CLIR applied can still be overridden in the destination network, whenever informa- tion on the calling line is available for this network. 4.4 Network capabilities for charging This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that infor- mation. It shall be possible to charge the subscriber accurately for the service. 4.5 Interworking requirements On calls to or via non-ISDNs, it cannot be assured that a CLIR indication can be carried to the destination network. As a national option the originating network shall have the possibility to res- trict any information identifying the calling party from being for- warded to the destination network when CLIR is applicable. If a network receives a calling party ISDN number without any indication of presentation allowed or restricted, the destination network (the host network) will act according to its rules and regulations. 4.6 Interaction with other supplementary services 4.6.1 Call Waiting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Assume that a call from a user at C, who has subscribed to the CLIR service, invokes Call Waiting at a user(s) at B. The user(s) at B would receive a call waiting indication but would not receive the number of the calling user at C when the call waiting indica- tion is given. 4.6.2 Call Transfer Assume that a user A has an established call with user B and wishes to transfer this call with user B to user C. If user A has subscribed to CLIR, then user C shall not receive a calling number when user A invokes any call transfer procedure. If user B has sub- scribed to CLIR, then user C shall not receive a calling number during the transfer of user B to user C. 4.6.3 Connected Line Identification Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.4 Connected Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.5 Calling Line Identification Presentation CLIR will take precedence over Calling Line Identification Presentation (CLIP). The only occasion when a user subscribing to CLIP can take precedence over CLIR is when the user has an override category. This is a national option. 4.6.6 Calling Line Identification Restriction Not relevant. 4.6.7 Closed User Group No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.8 Conference Calling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.9 Direct-Dialling-In No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.10 Call Diversion (i.e. Call Forwarding) services 4.6.10.1 Call Forwarding Busy When CLIR is applicable and activated, the calling party's ISDN-number will not be presented to the "forwarded-to" user unless this user is in an override category. The latter is a national option. 4.6.10.2 Call Forwarding No Reply When CLIR is applicable and activated, the calling party's ISDN-number will not be presented to the "forwarded-to" user unless this user is in an override category. The latter is a national option. 4.6.10.3 Call Forwarding Unconditional When CLIR is applicable and activated, the calling party's ISDN-number will not be presented to the "forwarded-to" user unless this user is in an override category. The latter is a national option. 4.6.11 Line Hunting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.12 Three-Party Service No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.13 User-to-User Signalling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.14 Multiple Subscriber Number No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.15 Call Hold No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.6.16 Advice of Charge No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 4.7 Dynamic description The dynamic description for this service is shown in Figure 1/I.251. 5 I.251.5 - Connected Line Identification Presenta- tion 5.1 Definition Connected Line Identification Presentation (COLP) is a supple- mentary service offered to the calling party which provides the connected party's ISDN-number to the calling party. 5.2 Description 5.2.1 General description When COLP is applicable and activated, the network provides the calling party with the number of the connected party when the connected party answers the incoming call. The network should be capable of transmitting at least 15 digits (maximum length of an ISDN number). Note - The possibility of enhancing this service to provide the called party number before the called party answers the call is for further study. 5.2.2 Specific terminology None identified. 5.2.3 Qualifications on the applicability to telecommunica- tion services This supplementary service is applicable to all telecommunica- tion services. It is to be noted that in the Telematic services an exchange of Terminal Identification (TID) occurs at a higher layer subsequent to a successful call establishment. For Telematic services this supplementary service shall con- sist only of the access number of the connected party and this shall be provided by the network. For other non-voice services this supplementary service is for further study. The presentation of the connected party's ISDN number by Telematic terminals and by other non-voice terminals is for further study. 5.3 Procedures 5.3.1 ProvisionB/Fwithdrawal The COLP supplementary service may be provided on a subscrip- tion basis or be generally available. COLP may be withdrawn at the request of the subscriber or by the network provider for administrative reasons. 5.3.2 Normal procedures 5.3.2.1 ActivationB/FdeactivationB/Fregistration COLP is activated on provision and deactivated on withdrawal. No information needs to be registered with the network for this supplementary service. 5.3.2.2 Invocation and operation The number presented shall unambiguously identify the access of the connected party. The number presented is either: i) completely provided by the network; ii) completely provided by the connected party; or iii) partially provided by the network with the rest provided by the connected party (e.g. the access number is provided by the network and the additional digits to make the number complete by the connected party). Where either the complete connected number, or part of the connected number is initially provided by the connected party, the network shall check its validity. If this check is successful then this number is used by the network. 5.3.3 Exceptional procedures 5.3.3.1 ActivationB/FdeactivationB/Fregistration None identified. 5.3.3.2 Invocation and operation There are two cases where the connected party number is not presented to the calling party: i) when the connected party has an arrangement whereby presentation of his number is not allowed (see definition of Connected Line Identification Restriction); or ii) when the connected party number is not avail- able (e.g. due to interworking with the analogue telephone network (PSTN)). In such cases the calling party shall be given a number una- vailable indication. If the network check on the connected party provided number is unsuccessful, the network default number will be used instead. 5.3.4 Alternative procedures 5.3.4.1 ActivationB/FdeactivationB/Fregistration None identified. 5.3.4.2 Invocation and operation In some cases where a connected party has an arrangement such that presentation of his number is not allowed, there may be cer- tain categories of calling party that have the ability to override this restriction and have the connected number presented. This function is a national matter. Problems may occur when the connected party does not belong to the same network as the calling party and in the connected party's network the override category does not exist, while in the calling party's network, it does exist. A problem occurs when a connected party who restricts presentation and assumes that his number is never presented, receives a call from a calling party who is in the override category. The cases where the override category is applied is a national matter. Depending on bilateral agreement about the application of the override category in country A, and the presentation not allowed arrangement of the connected party in country B, country B may or may not deliver the connected line identification to country A. Agreements are also needed with any transit network. 5.4 Network capabilities for charging This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that infor- mation. It shall be possible to charge the subscriber accurately for the service. 5.5 Interworking requirements On calls destined to some non-ISDN networks, the connected number may be delivered to the originating ISDN without the ability to indicate whether presentation is allowed or not. How the ISDN should behave in this case is for further study. On calls destined to some other non-ISDN networks, no con- nected party number may be available to the ISDN and therefore the full number of the connected party cannot be given to the calling party who has been provided with COLP. In this situation a partial number shall be given unless no information is available whereupon a "number unavailable indication" is given to the calling party. 5.6. Interaction with other supplementary services 5.6.1 Call Waiting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.2 Call Transfer Assume the situation where a user A has an established call with a user B and wishes to transfer this call with user B to a user C. Except in the case where user C prohibits the presentation of his number, user C's number shall be presented: - to user B upon successful completion of the transfer to user C (independent of the type of transfer procedure invoked by user A) provided that user B has subscribed to COLP; - to user A when user A is using normal or expli- cit transfer procedures and has subscribed to COLP. The connected party's number will not be presented to user A if user A invokes the single step Call Transfer procedure. Note - The connected number presentation may not be possible if interworking with a non-ISDN network is invoked in the call transfer. 5.6.3 Connected Line Identification Presentation Not applicable. 5.6.4 Connected Line Identification Restriction The connected line identification will not be presented if the connected user has subscribed to COLR. 5.6.5 Calling Line Identification Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.6 Calling Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.7 Closed User Group No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.8 Conference Calling A conference controller who has also subscribed to COLP should be presented with the connected party's number when that party is either part of the initial activation of the conference or is added as a new conferee to an existing conference. Conferees in an existing conference who have subscribed to COLP will not receive a new party's number whenever a conference controller adds a new party to the conference. 5.6.9 Direct-Dialling-In For further study. 5.6.10 Call Diversion (i.e. Call Forwarding) services 5.6.10.1 Call Forwarding Busy (CFB) No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Assume a calling user A, who has subscribed to COLP, places a call to a user B who is busy and this call is forwarded to a user C. If user B has also subscribed to a notification option with his CFB service, calling user A may receive the forwarded-to user C's number with the notification of the forwarding. In any event, assuming user C answers the call, user C's number will be returned to user A unless user C has subscribed to COLR. 5.6.10.2 Call Forwarding No Reply (CFNR) No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Assume a calling user A, who has subscribed to COLP, places a call to a user B who has subscribed to the CFNR service, and who does not reply to the call within the subscribed time interval. If user B has also subscribed to a notification option with his CFNR service, calling user A may receive the forwarded-to user C's number with the notification of the forwarding. In any event, assuming user C answers the call, user C's number will be returned to user A unless user C has sub- scribed to COLR. 5.6.10.3 Call Forwarding Unconditional (CFU) No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Assume a calling user A, who has subscribed to COLP, places a call to a user B who has subscribed to the CFU service. This call to user B would then be forwarded to user C. If user B has also subscribed to a notification option with his CFU service, calling user A may receive the forwarded-to user C's number with the notif- ication of the forwarding. In any event, assuming user C answers the call, user C's number will be returned to user A unless user C has subscribed to COLR. 5.6.11 Line Hunting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.12 Three-Party Service No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.13 User-to-User Signalling No impact, i.e. neither supplementary service affects the the other supplementary service. 5.6.14 Multiple Subscriber Number Assume user A, who has subscribed to COLP, places a call to a user B to whom the network is applying the MSN service. Assuming user B answers the call, the connected number at B (which may be identical to the called number) will be returned to user A unless user B has subscribed to COLR. Other interactions are for further study. 5.6.15 Call Hold No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.6.16 Advice of charge No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 5.7 Dynamic description The dynamic description for this service is shown in Figure 2/I.251. 6 I.251.6 - Connected Line Identification Restriction 6.1 Definition Connected Line Identification Restriction (COLR) is a supple- mentary service offered to the connected party to restrict presen- tation of the connected party's ISDN-number to the calling party. 6.2 Description 6.2.1 General description When COLR is applicable and activated, the destination node provides the originating node with a notification that the con- nected party's ISDN number is not allowed to be presented to the calling party. In this case no connected party number is included in the call connected information to the calling party's installa- tion. Note - When COLR is subscribed to, some network providers may not wish to send the identity of the connected customer to other network providers. 6.2.2 Specific terminology None identified. 6.2.3 Qualifications on the applicability to telecommunica- tion services None identified, i.e. this supplementary service is applicable to all telecommunication services. Figure 2/I.251, p. Figure 2/I.251 (feuillet 2 sur 2), p. 6.3 Procedures 6.3.1 ProvisionB/Fwithdrawal COLR can be provided on a subscription basis or be generally available. As a network provider option, COLR can be offered with several subscription options. The options apply separately to each ISDN number. Subscription options are summarized below: Subscription option Values COLR mode - permanent (active for all calls) - temporary (specified by user per call) Default - presentation restricted (only for temporary mode) - presentation not restricted It is a network provider option to specify either or both of the above options for all subscribers, for instance, in an exchange or network. 6.3.2 Normal procedures 6.3.2.1 ActivationB/FdeactivationB/Fregistration If subscribed to in the permanent mode, COLR is always activated. If subscribed to on a temporary basis, COLR is activated upon explicit request for the service, or on default, on a particu- lar call and is deactivated after that call. 6.3.2.2 Invocation and operation If the calling party subscribes to Connected Line Identifica- tion Presentation and the connected party has COLR activated, the calling party shall receive an indication that the connected party number is not available. 6.3.3 Exceptional procedures 6.3.3.1 ActivationB/FdeactivationB/Fregistration No exceptional procedures identified. 6.3.3.2 Invocation and operation No exceptional procedures identified. 6.3.4 Alternative procedures 6.3.4.1 ActivationB/FdeactivationB/Fregistration No alternative procedures identified. 6.3.4.2 Invocation and operation Certain countries may define categories of subscribers that have the ability to override the presentation restriction and have the connected party's ISDN number presented (e.g. the police). The ability to have such an override option is a national matter. When a call originates in one ISDN and terminates in another ISDN and COLR is applied, the rules and regulations of the destina- tion network (the host network) should apply. For example, if the override category is not applicable in the originating network but it is in the destination network, a call with COLR applied can still be overridden in the destination network, whenever informa- tion on the connected line is available for this network. 6.4 Network capabilities for charging This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that infor- mation. It shall be possible to charge the subscriber accurately for the service. 6.5 Interworking requirements On calls to or via non-ISDNS, it cannot be assured that a COLR indication can be carried to the originating network. As a national option the destination network shall have the possibility to res- trict any information identifying the connected party from being returned to the originating network when COLR is applicable. If a network receives a connected party ISDN number without any indica- tion of presentation allowed or restricted, the originating network (the host network) will act according to its rules and regulations. 6.6 Interaction with other supplementary services 6.1 Call Waiting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Assume that a call from a user C, invokes Call Waiting at user B, who has subscribed to the COLR service. User B would receive a call waiting indication but would not have his number returned when the call waiting indication is given. 6.6.2 Call Transfer Assume that user A has an established call with user B and wishes to transfer this call with user B to a user C. If user C has subscribed to COLR, then user A shall not receive the connected number when user A invokes any call transfer procedure. If user C has subscribed to COLR, then user B shall not receive the connected number during the transfer of user B to user C. 6.6.3 Connected Line Identification Presentation COLR will take precedence over COLP. The only occasion when a user subscribing to COLP can take precedence over COLR is when the user is in an override category. This is a national option. 6.6.4 Conencted Line Identification Restriction Not relevant. 6.6.5 Calling Line Identification Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.6 Calling Line Identification Restriction No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.7 Closed User Group No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.8 Conference Call No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.9 Direct-Dialling-In No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.10 Call Diversion (i.e. Call Forwarding) services 6.6.10.1 Call Forwarding Busy When the diverted call is finally answered, no connected number will be presented to the calling party unless this party is in an override category. The latter is a national option. 6.6.10.2 Call Forwarding No Reply When the diverted call is finally answered, no connected number will be presented to the calling party unless this party is in an override category. The latter is a national option. 6.6.10.3 Call Forwarding Unconditional When the diverted call is finally answered, no connected number will be presented to the calling party unless this party is in an override category. The latter is a national option. 6.6.11 Line Hunting No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.12 Three-Party Service No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.13 User-to-User Signalling No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.14 Multiple Subscriber Number No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.6.15 Call Hold No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.16 Advice of charge No impact, i.e. neither supplementary service affects the operation of the other supplementary service. 6.7 Dynamic description The dynamic description for this service is shown in Figure 2/I.251. 7 I.251.7 - Malicious Call Identification This service, having been identified, now requires further study, its description is not yet included. 8 I.251.8 - Sub-addressing This service, having been identified, now requires further study, its description is not yet included. 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