Enhanced Mid-Call Diversion

Issue 2 Enhanced Mid-Call Diversion Page 1 of 29

CONTENTS 1. SCOPE AND OBJECTIVES... 4 2. INTRODUCTION... 5 General Description... 5 2.1. Enhanced Mid Call Diversion Overview... 5 3. TERMINOLOGY... 8 4. BASIC EMCD DIVERT... 9 4.1. Service Description... 9 4.2. Customer Requirements... 10 5. RE-PRESENTATION... 11 5.1. Supplementary Service Description... 11 5.2. Customer Requirements... 12 6. HOME GROUP DIVERT... 13 6.1. Supplementary Service Description... 13 6.2. Customer Requirements... 14 7. ENQUIRY CALL SETUP... 15 7.1. Supplementary Service Description... 15 7.1.1. Voice Path Configuration... 16 7.2. Customer Requirements... 16 8. SUB-ADDRESS... 17 8.1. Supplementary Service Description... 17 8.2. Customer Requirements... 17 9. CALL TYPE OVERRIDE... 18 9.1. Supplementary Service Description... 18 9.2. Customer Requirements... 18 10. VOICE PATH REQUEST... 19 10.1. Supplementary Service Description... 19 10.2. Customer Requirements... 19 11. INFORMATION FORWARDING... 20 11.1. Supplementary Service Description... 20 11.2. Customer Requirements... 20 12. CALL CLEAR... 21 12.1. Supplementary Service Description... 21 12.2. Customer Requirements... 21 Page 2 of 29

13. CHANNEL BLOCKING... 22 13.1. Supplementary Service Description... 22 13.2. Customer Requirements... 22 14. ABBREVIATIONS AND GLOSSARY... 23 15. REFERENCES... 23 ANNEX A - GENERIC KEYPAD PROTOCOL... 24 Coding of Keypad Facility Information... 24 ANNEX B KEYPAD MESSAGE FORMAT... 25 Annex B.1 - Basic EMCD Divert (Keypad facility information content)... 25 Annex B.2 - Re-presentation (Keypad facility information content)... 25 Annex B.3 - Home Group Divert (Keypad facility information content)... 25 Annex B.4 - Enquiry Call Setup (Keypad facility information content)... 26 Annex B.5 - Sub-address (Keypad facility information content)... 26 Annex B.6 - Call Type Override (Keypad facility information content)... 26 Annex B.7 - Voice Path Request (Keypad facility information content)... 27 Annex B.8 - Information Forwarding (Keypad facility information content)... 29 Annex B.9 - Call Clear (Keypad facility information content)... 29 Annex B.10 Channel Blocking (Keypad facility information content)... 29 Page 3 of 29

1. SCOPE AND OBJECTIVES The objective of this document is to explain the functionality of the supplementary services that form the Enhanced Mid-call Diversion Service. This document is directed at customers and potential customers of this service and serves to detail the functionality available and how to initiate these functions. It should be noted that this document is a guide, the definitive technical reference is Supplier Information Note 316, [3]. Enquiries relating to SIN 316 should be directed to: Interoperability & Technical Regulatory Services PP: 2D27 403 St John Street LONDON EC1V 4PL SIN Helpline 0800 318601 http://www1.btwebworld.com/sinet/ Page 4 of 29

2. INTRODUCTION General Description The BT Enhanced Digital Value Call Access service uses an ISDN I.421 primary rate access and complements the existing BT ISDN 30e (I.421) Service as defined in SIN 261, [4]. The Enhanced Digital Value Call Access service is available to customers (who will typically be Service Providers) employing direct trunk level connection to the BT network for high traffic, multiple line call delivery. The introduction of the ISDN option for this type of delivery provides a number of improvements over earlier signalling systems employed, particularly fast call set-up and CLI presentation. The BT Enhanced Digital Value Call Access service provides the same basic call service features (i.e. bearer services and teleservices) as defined in SIN 261, [4] with the exception that the service is an incoming only service i.e. outgoing call barring is permanently activated on all calls. In addition, it should be noted that first party call clearing is applied to all call types (i.e. to speech as well as 64 kbit/s data calls, to calls inter-working with the PSTN, etc). The BT Enhanced Digital Value Call Access service supports the following supplementary services, which unless stated otherwise, will be implemented as defined in SIN 261, [4]): Calling Line Identification Presentation; Calling Line Identification Restriction; Direct Dialling In; MCId (Malicious Call Identification) is supported using the same signalling mechanisms as defined in SIN 261, [4]. Details of the implementation of this supplementary service as it applies to Enhanced Digital Value Call Access are given in SIN 316, [3]. Sub-addressing is supported but is limited to 20 octets of sub-address information see Annex B.5 and SIN 316, [3] for details. Customer controlled channel blocking supplementary service (this service is not defined in SIN 261 - see Annex B.10 for details) Enhanced Mid Call Diversion (EMCD) as defined within this document and SIN 261, [4]. 2.1. Enhanced Mid Call Diversion Overview EMCD call control is achieved using the generic keypad stimulus protocol (see Annex A). The keypad protocol allows control strings of characters to be transmitted both from the CPE to the network and from the network to the CPE. This takes place in the ISDN D channel and is inaudible to either party of the call. Page 5 of 29

As normal ISDN call set-up is not used the 2nd leg call is set up by the network, under the indirect control of the CPE. Therefore in the case of basic EMCD operation the ISDN call characteristics (e.g. call bearer capability and low and high level compatibility fields) are copied from the established call s parameters. By using the more advanced features provided EMCD it is possible, if desired, to modify these call parameters. Enhanced Digital Value Call Access Calling User () network Served User () Diverted to User () On successful invocation of EMCD, the call between Users A and B is diverted in the network so that it is between Users A and C. The B-channel on the access to is then free to handle Figure 2.1 Example of EMCD Scenario A typical EMCD call sequence will be as follows (with reference to Figure 2.1): (i) A normal call is established (between users A and B). The served user (B) engages in a dialogue with the calling user (A) until the need to invoke the EMCD occurs. (ii) The served user (B) uses the Keypad Protocol (abbreviated to a keypad message in this text) to send a message requesting EMCD and containing the number of the diverted to user (). Note: a free B-channel on the Enhanced Digital Value Call Access is not required for this potential connection to the diverted party. All call progress information relating to this connection is provided as messages in the D-channel (see point iv below). (iii) The Network receives and interprets the message and sets up a 2nd leg route using the diverted to number obtained from the received keypad message. The calling party (A) still has a two way voice path to the served user (B) during this process, so a courtesy announcement or music-on-hold can be provided by the served user (B) to. (iv) Call progress messages received on the 2nd leg route are forwarded back to the served user (B) in keypad messages. The served user (B) can use this information to give meaningful call progress indication (over the B-channel) to the calling user (A) in the event that the diverted to number () is engaged or otherwise unobtainable. Page 6 of 29

(v) On answer by of the 2nd leg route, the network clears the call and B-channel connection to the served user (B), leaving the calling (A) and called (C) users connected together until either one clears. This frees the B- channel to for reuse. (NB: will continue to pay for the call between Users A and C following EMCD and has no control over that connection ie only or can clear the connection). Network SETUP Served User () CALL PROCEEDING ALERTING CONNECT Normal call establishment between Users A and B CONNECT ACKNOWLEDGE INFORMATION (Keypad {EMCD Request}) INFORMATION (Keypad {EMCD Response eg Call Progress, Error}) invokes EMCD using Generic Keypad signalling CPE can maintain dialogue with during diversion process. When the second leg is answered the first leg call is cleared DISCONNECT RELEASE RELEASE COMPLETE Network forward clears and connects to Figure 2.2 - Typical DSS1 Call Message Sequence for Basic EMCD Page 7 of 29

3. TERMINOLOGY This section has been provided to give a brief introduction to the terminology that will be presented in this document. ISDN (Integrated Digital Services Network) An ISDN network provides an end to end digital connectivity to support a wide range of services including voice and non voice, e.g. data, video, fax etc. Keypad Protocol The Keypad protocol provides a means of tranferring keypad facility codes from the user to the network to control supplementary services and indicating network responses to the user. Sub-address The sub-address enables expansion of the customer s addressing capacity beyond the basic ISDN number. This service is provided to the called user. Logical Group A method whereby a one or more 2MHz links (of 30 circuits) can be grouped to effectively form a single pseudo trunk of 30 or more circuits (in multiples of 30). Page 8 of 29

4. BASIC EMCD DIVERT The Basic EMCD service has already been rolled out to the field. A number of new supplementary services have been added to the basic service. Details on invoking this service can be found in Annex B.1. A description of the basic service is given below. 4.1. Service Description The basic EMCD service may be invoked during the active phase of a call. The service is requested by the sending of an INFORMATION message to the network containing a Keypad facility information element containing the number of the diverted to user. The phases of a Basic EMCD Call Setup are detailed in the diagram below: i) Call presented to CPE ii) CPE Requests Divert iii) Network Generates 2 nd Leg iv) Call is diverted 2nd leg call set up 2 nd leg answered Phases of Basic EMCD Call SetupOn receipt of a valid EMCD request, the network will attempt to establish a connection to the diverted to user using the same call characteristics (Bearer capability, High and Low layer compatibility information element coding) as the active call. If the EMCD request is: (i) successful, the network shall send an INFORMATION message to the served user containing a Keypad facility information element containing the appropriate call progress information code. (ii) unsuccessful (e.g. the diverted to address is invalid, the diverted to user is busy), then the EMCD request will be rejected by the network sending an INFORMATION message to the served user containing a Keypad facility information element containing the appropriate call progress information code. Page 9 of 29

When the diverted to user () answers, the network will complete the transfer and forward clear the served user (), thus the served user has no further control over the call and the control is passed to the calling () and diverted to () users. Note 1: If the served user clears the call after initiating an EMCD request and before the final destination has answered the diversion continues, with any appropriate in-band tones audible to the calling user (). Note 2: The served user () can cancel an EMCD request at any time prior to either: (i) the network rejecting the EMCD request, or (ii) the network clearing the call to the served user () as a result of successful invocation of EMCD, by the served user sending an INFORMATION message to the network containing a Keypad facility information element containing a Clear Request. (Note: in case (II) there is a possibility that a DISCONNECT message sent from the network as a result of successful EMCD crosses over with a EMCD Clear Request from the served user. In this case, the EMCD Clear Request will be ignored by the network and the successful EMCD will be completed.) 4.2. Customer Requirements No specific customer details that require configuration by BT are associated with the basic service. Page 10 of 29

5. RE-PRESENTATION This Supplementary Service allows the CPE to request that it (or another CPE served from the same network termination point) be reconnected to the caller if the 2 nd leg of the call clears. Details on invoking this service can be found in Annex B.2. 5.1. Supplementary Service Description This Supplementary Service allows the CPE to request that the calling user () be reconnected to it (or another CPE served from the same network termination point) if the 2nd leg of the call clears. It should be noted that as this Supplementary service requires first party release on the second leg it is limited to use on non-geographic destination numbers (e.g. 0800, 0345, etc) and certain mobile and ISDN destinations. The served user () is able to select a call re-presentation supplementary service when setting up a diversion, at the same time specifying a destination route (from a pre-defined list of up to 10 routes held by the network) and the called number to be delivered as part of the re-presentation call set-up. If no such route exists then the network will reject the request. If Call Re-presentation is selected then once a call that has been successfully diverted and is subsequently backward cleared by the divert party () then is put on hold while a new call is set up to the new served user (). Whilst on hold, will be presented with silence whilst the new call is initiated. is then able to answer the new call and resume interaction with. It should be noted that as this is a new call it can fail if routes to are busy at the time. Page 11 of 29

i) Call presented to CPE ii) CPE Requests Divert iii) Network Generates 2 nd Leg iv) Call is diverted 2nd leg call set up 2 nd leg answered v) 2 nd leg Clears vi) Call Represented to CPE on new no. 2 nd leg cleared Phases of Representation Divert Call Setup 5.2. Customer Requirements It will be necessary to capture the customers route requirements for this supplementary service. When making a re-presentation request it is necessary for the served user () to specify the destination route. The route will specify the destination number and the Logical Group via which the number will be routed. This destination route is selected from a predefined list of up to 10 routes numbered from 0 to 9 inclusive. The customer may choose to have access to any number of these routes upto the maximum of 10. It should be noted that it is not necessary for the customer to have consecutive routes, it is quite possible to have access to routes 2, 5 & 9 but not the remaining seven routes. Page 12 of 29

6. HOME GROUP DIVERT This Supplementary Service allows the served user (CPE) to divert the call to another CPE port on the same customer access group without diverting out to the network first. Details on invoking this service can be found in Annex B.3. 6.1. Supplementary Service Description Home Group Divert operates in a similar manner to normal EMCD call set-up. However, rather than routing the call via the public network which would result in additional cost to the CPE the call is immediately routed across to another CPE on the same network Home Group. In short the call is simply moved from the CPE to another CPE on the same network termination point. If on receipt of a call the served user 1 (1) selects Home Group Divert then the network selects the appropriate route from a pre-defined set based on the Route Number parameters supplied by the CPE, and sets up a call up to that destination. For each available number there is a maximum of 10 available routes. If no such route exists then the request will be rejected. The called number used is that contained in the Called Number parameter supplied by the CPE. This call and subsequent transfer then progresses as for any other EMCD call. On receipt of a Home Group Divert request the process begins immediately. Any previous or following Call Re-presentation or Enquiry Call requests and any previously specified Destination Address fields are ignored, e.g. Home Group Divert requests override Call Representation or Enquiry Call requests. Page 13 of 29

i) Call presented to CPE1 ii) CPE1 Requests Divert to CPE2 1 1 2 2 iii) Network Hands call to CPE2 1 2 2nd leg call set up Forced Re-presentation complete, 2 may now make MCD request v) Network Generates 2 nd Leg iv) CPE2 Requests Divert 1 1 2 2 2 nd leg answered 2nd leg call set up vi) Call is diverted 1 2 2 nd leg answered 6.2. Customer Requirements Phases of Home Group Divert Call Setup It will be necessary to capture the customers route requirements for this supplementary service. There is a maximum of 10 routes available for use with this supplementary service. When making a Home Group Divert request it is necessary for the served user () to specify the destination route. The route will specify the destination number and the Logical Group via which the number will be routed. This destination route is selected from a pre-defined list of up to 10 routes numbered from 0 to 9 inclusive. The customer may choose to have access to any number of these routes upto the maximum of 10. It should be noted that it is not necessary for the customer to have consecutive routes, it is quite possible to have access to routes 2, 5 & 9 but not the remaining seven routes. Page 14 of 29

7. ENQUIRY CALL SETUP This Supplementary Service allows the CPE to setup the 2 nd leg call on a separate B channel from the incoming call and then subsequently connect the two calls together to complete the transfer. Details on invoking this service can be found in Annex B.4. 7.1. Supplementary Service Description The enquiry call set-up service allows the served user () to use a second CPE B channel to set up the 2nd leg of an MCD call completely independently from the 1 st leg. may then engage in a dialogue with the 2nd leg via the second channel without putting the calling user () on hold. If prior to specifying the destination address, the selects Enquiry Call set-up then the following sequence is used to set up the EMCD call: 1. The network allocates a 2nd B channel on the same physical 2 Mbits -1 bearer as the existing call (if this allocation fails then the EMCD call will fail with code 317 enquiry call user busy ). 2. The network then sets-up a call into the 2nd CPE B channel using the Called Number specified in the Enquiry Call Request. Call progress information is relayed to the 1st CPE channel in Call Progress Information messages. 3. On answer of the 2nd channel the network commence the set-up of the call to the 2nd leg destination. The answer on the 2nd CPE channel is also reported to the 1st CPE channel in a Call Progress Information message. 4. While the 2nd leg call set-up proceeds the two CPE channels may exchange information using the Information Forwarding Request service. 5. Call progress information on the 2nd leg call is relayed to both CPE channels in Call Progress Information messages. 6. On 2nd leg call answer the diverted to user () is connected to the 2nd CPE channel. The CPE may now engage in independent dialogues on both channels. If necessary it may still exchange Information Forwarding Requests with the 1 st channel via the network. 7. To transfer the call the served user () clears the 1st CPE call. The network then clears the 2nd CPE call and connects the calling user () and diverted to user () as for a normal EMCD call. Page 15 of 29

8. If user B invokes the call clear service on the 1st CPE channel, or forward clears the 2nd CPE channel then the 2nd leg call shall be cleared and the network revert to the normal active call state. The phases in Enquiry Call set-up are shown below: i) Normal call ii) CPE requests enquiry call New call on 2nd B channel iii) Two channels set up iv) Call is diverted 2nd leg call set up Phases of Enquiry Call Set-up Note: It is necessary for to be able to relate the calls on the two CPE B channels as part of the same Enquiry Call set-up, the method for doing this is an issue for the CPE application. 7.1.1. Voice Path Configuration The Dual Channel Setup or Enquiry Call Supplementary Service can be used in conjunction with the Voice Path Configuration. Full details on this Supplementary Service can be found in section 9. However, it should be noted that a change to the voice path configuration in conjuction with Dual Channel Setup or Enquiry call may only be initiated between stages III and IV of the diagram detailed above. 7.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service Enquiry Call. Page 16 of 29

8. SUB-ADDRESS This Supplementary Service allows the served user (CPE) to specify an ISDN sub address in addition to the diverted call party number. Details on invoking this service can be found in Annex B.5. 8.1. Supplementary Service Description The served user () is able to include sub-address information when setting up a diversion. The sub-address information may consist of up to 20 IA5 characters, and will be presented as a user defined format sub-address. 8.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service Sub-address. Page 17 of 29

9. CALL TYPE OVERRIDE This Supplementary Service allows the served user (CPE) to select the outgoing call type (this is normally copied from the incoming call) from a limited range of options. For example it could request an ISDN only call even if the incoming call originated from the PSTN. Details on invoking this service can be found in Annex B.6. 9.1. Supplementary Service Description Normally the 2 nd leg call type will be of the same as the 1st leg call type, however, this service allows a different call type to be selected from a pre-defined set. The Bearer capability, Low level compatibility and High level compatibility fields of the outgoing call may be selected as follows: (Note all other Call Types Codes are reserved for future use.) Call Type SETUP information elements 1 Data (64 kbits -1 unrestricted) 2 Speech 3 3.1kHz Audio 4 Telefax Group 4 5 Telefax Group 2/3 9.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service Call Type override. Page 18 of 29

10. VOICE PATH REQUEST This Supplementary Service overrides the immediate completion of the call transfer following answer by the divert party allowing the CPE to switch tranmission between the calling party and called party on completion of transfer. Details on invoking this service can be found in Annex B.7. 10.1. Supplementary Service Description The served user () is able to specify the voice path configuration to be applied once the 2nd leg of the EMCD call has answered. It is also for user B to select further configurations following 2nd leg call answer. The voice path is selected from one of the following configurations: 1 2 3 4 5 Voice Path Configurations The Path Number parameter supplied by the CPE selects one of the voice path configurations, as numbered in the figure detailed above. If a Path Number parameter of 0 is specified, then on 2nd leg answer the CPE call is cleared and the calling user () and diverted to user () are immediately connected. A Path Number parameter of 0 is the implicit default on all calls where no Voice Path Control request is used. 10.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service Voice Path Configuration. Page 19 of 29

11. INFORMATION FORWARDING This Supplementary Service allows the CPE to communicate with another CPE on the same customer access group using information in keypad facility information elements. It should be noted that this Supplementary Service can only be used between two IVR channels and as such can only be used in Enquiry Call and Home Group divert calls. Information can be forwarded in either direction as required. Details on invoking this service can be found in Annex B.8. 11.1. Supplementary Service Description The <Escaped IA5> string supplied by the CPE is forwarded to either the second CPE channel in an Enquiry Call EMCD call set-up, or the destination CPE in a Home Group Transfer. If no 2nd CPE channel exists at the time the CPE issues the Information Forwarding request, then the request will be ignored. It is possible for the 2nd CPE to send strings back to the 1st CPE using information forwarding requests without invoking other MCD services. The forwarded information strings are terminated by the end of the Keypad Facility information element as only a single string is sent in a message. 11.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service Information Forwarding. Page 20 of 29

12. CALL CLEAR This Supplementary Service allows the IVR to clear any second leg call once it has been initiated. Details on invoking this service can be found in Annex B.9. 12.1. Supplementary Service Description This Supplementary Service allows the IVR to clear any second leg call once it has been initiated. In the case of Enquiry Call setup the Clear Request Supplementary Service shall clear both parties of the 2 nd leg call setup. In the event that another Supplementary Service is included in the same keypad message as a Clear Request the Clear request shall take priority. All other requests in the same keypad are ignored but not rejected. 12.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service Clear Call. Page 21 of 29

13. CHANNEL BLOCKING This Supplementary Service allows the blocking of incoming calls to individual B-channels or all B-channels in the primary rate access associated with the signalling D-channel. Details on invoking this service can be found in Annex B.10. 13.1. Supplementary Service Description This service allows the blocking of incoming calls to individual B-channels or all B- channels in the primary rate access associated with the signalling D-channel. This supplementary service is equivalent to the back busy feature available on Valuecall Digital Access product using channel associated A1/B1 signalling. This supplementary service allows the user to close off incoming calls in a controlled manner e.g. prior to maintenance activities on the CPE. It should be noted that this supplementary service cannot be used to unblock B-channels (or the whole primary rate access) that the network has taken out of service e.g. for maintenance reasons. B-channels blocked by the user as a result of invoking this supplementary service can be unblocked by the network. 13.2. Customer Requirements No specific customer details that require configuration by BT associated with the Supplementary Service B-channel blocking. Page 22 of 29

14. ABBREVIATIONS AND GLOSSARY CAS CLI CPE DDI EMCD ISDN IVR MCD MCId PSTN SP Channel Associated Signalling Calling Line Identity Customer Services Equipment Direct Dial In Enhanced Mid call Diversion Integrated Digital Services Network Intelligent Voice Response Mid Call Diversion Malicious Call Identification Public Swithced Telephone Network Service Provider 15. REFERENCES [1] ETS 300 122-1 (1992) ISDN: Generic keypad protocol for the support of supplementary services [2] ETS 300 738 (1997) Minimum Man-Machine Interface to public network based supplementary services [3] Suppliers Information Note 316 Enhanced Digital Value Call Access Service Description, http://www1.btwebworld.com/sinet/ [4] Suppliers Information Note 261 BT ISDN 2e and ISDN 30 (I.421) Service using full ETSI Call Control, http://www1.btwebworld.com/sinet/ Page 23 of 29

ANNEX A - GENERIC KEYPAD PROTOCOL Coding of Keypad Facility Information Some supplementary services use the Generic Keypad Protocol that is defined in ETS 300 122-1 [1]. The format of the Keypad facility information IA5 character string to be contained in the Keypad facility information element aligns with the format defined in ETS 300 738 [2]. This format is as follows (using Backus-Naur notation see Note): <Keypad facility information> ::= <Service Prefix> <Service Code> {<Service Separator> <Supplementary Information>} <Service Suffix> <Service Separator> ::= * <Service Suffix> ::= # The definition of <Service Prefix>, <Service Code> and <Supplementary Information> are specific to each supplementary service and are defined in the section in this SIN describing the supplementary service. Note: In the Backus- Naur notation: A sequence of characters enclosed in the brackets < > is a description of an entity eg <Keypad facility information>, Braces { } mean that the enclosed item can be repeated 0 (ie the item is absent) or more times, Square brackets [ ] indicate that enclosed item is optional (ie it may be absent), The character ::= means is defined as, The character means (exclusive) or, Spaces are shown for clarity only, and Any other character not enclosed in the brackets < > represents itself and are to be IA5 encoded. Page 24 of 29

ANNEX B KEYPAD MESSAGE FORMAT Annex B.1 - Basic EMCD Divert (Keypad facility information content) *96*<Divert to Addess># e.g. To divert to 01473 640120 the request may be as follows: *96*01473640120# Annex B.2 - Re-presentation (Keypad facility information content) *96*R<Route Number><Called Number (Re-presentation)>*<Divert to Addess># e.g. To divert to 01473 640120 with a re-presentation request to 01473 606129 on route 2 the request may be as follows: *96*R201473606129*01473640120# This request may be entered as two requests as detailed below: *96*R201473606129# *96*01473640120# Annex B.3 - Home Group Divert (Keypad facility information content) To hand the call on to the second IVR using Home Group Divert the following request format is used: *96*F<Route Number><Home Group Divert Called Number># e.g. To initiate a Home Group Divert to 01473 606129 on route 2 the request may be as follows: *96*F201473606129# Following handover of the call, the second IVR may execute normal diversion using the standard EMCD request as detailed below: *96*<Divert to Addess># e.g. To divert to 01473 640120 the request may be as follows: *96*01473640120# Page 25 of 29

Annex B.4 - Enquiry Call Setup (Keypad facility information content) *96*D<IVR 2 nd Channel Address>*<Divert to Addess># e.g. To make an Enquiry Call Setup request to a final destination of 01473 640120 routing via a 2 nd channel on the IVR with an address of 12 the request may be made as follows: *96*D12*01473640120# This request may be entered as two requests as detailed below: *96*D12# *96*01473640120# Annex B.5 - Sub-address (Keypad facility information content) *96*S<sub-addess># e.g. To divert to 01473 640120 with a Sub-address of 5678 the request may be as follows: *96*S5678*01473640120# This request may be entered as two requests as detailed below: *96*S5678# *96*01473640120# It should be noted that this feature is not restricted to being used with the basic diversion feature only. The sub-address feature may also be used in conjunction with the following: Re-presentation; Home Group Divert; Dual Channel Setup or Enquiry Call; Call Type Override; Voice Path Configuration; e.g. To initiate a Home Group Divert to 01473 606129 on route 2 with a Sub-address of 5678 the request may be entered as follows: *96*S5678*F201473606129# Annex B.6 - Call Type Override (Keypad facility information content) *96*T<Call Type of Divert Leg># e.g. To divert to 01473 640120 with a Call Type of 2 the request may be as follows: Page 26 of 29

*96*T2*01473640120# This request may be entered as two requests as detailed below: *96*T2# *96*01473640120# Call Type Codes are as follows: Call Type SETUP information elements 1 Data (64 kbits -1 unrestricted) 2 Speech 3 3.1kHz Audio 4 Telefax Group 4 5 Telefax Group 2/3 It should be noted that this feature is not restricted to being used with the basic diversion feature only. The call type override feature may also be used in conjunction with the following: Re-presentation; Home Group Divert; Dual Channel Setup or Enquiry Call; Sub-address; Voice Path Configuration; e.g. To initiate a Home Group Divert to 01473 606129 on route 2 with a Sub-address of 5678 the request may be entered as follows: *96*S5678*F201473606129# Annex B.7 - Voice Path Request (Keypad facility information content) *96*P<Voice Path># e.g. To divert to 01473 640120 with a Voice Path of 3 the request may be as follows: *96*P3*01473640120# This request may be entered as two requests as detailed below: *96*P3# *96*01473640120# Page 27 of 29

Voice Path Configurations are as detailed below: 1 2 3 4 5 Voice Path Configurations It should be noted that when the Voice Path Configuration Supplementary Service is used in conjuction with the Dual Channel Setup or Enquiry Call Supplementary Service the request must be made between stages III and IV of the diagram Phases of Dual Channel Setup or Enquiry Call Set-up as detailed in section 6.1. If a Voice Path and Dual Channel Setup or Equiry Call request are made in the same keypad message the Voice Path request will be ignored and the Dual Channel Setup or Enquiry Call request will be processed as expected. It should be noted that this feature is not restricted to being used with the basic diversion feature only. The voice path feature may also be used in conjunction with the following: Re-presentation; Home Group Divert; Dual Channel Setup or Enquiry Call; Call Type Override; Sub-address; e.g. To initiate a Home Group Divert to 01473 606129 on route 2 with a Sub-address of 5678 the request may be entered as follows: *96*S5678*F201473606129# Page 28 of 29

Annex B.8 - Information Forwarding (Keypad facility information content) *96*I<Information># e.g. To send the information HELLO the request may be as follows: *96*IHELLO# This information will then be forwarded to the other IVR channel taking part in the call in the form: *96*FHELLO# Annex B.9 - Call Clear (Keypad facility information content) The keypad message to invoke the Clear Request is simply: *96*C# Annex B.10 Channel Blocking (Keypad facility information content) This supplementary service uses the Generic Keypad Protocol defined in ETS 300 122-1 [1]. The format of the Keypad facility information IA5 character string is as follows: <Service Prefix> ::=<Block> <Unblock> <Block> ::= * <Unblock> ::= # <Service Code> ::= 93 <Supplementary Information> ::= <B-channel> <B-channel> ::= <Digit> [<Digit>] <Digit> ::= 0 1 2 3 4 5 6 7 8 9 Note: 1. Where the optional B-channel parameter is not included then all B-channels associated with the signalling D-channel shall be blocked/unblocked. 2. B-channel is in the range 1 to 30 inclusive 3. Insertion of a leading zero for B-channel numbers less than 10 is optional i.e. both B-channel number 02 and 2 will be a valid number for B-channel number 2. End of Document Page 29 of 29