Suppliers' Information Note. BT Broadband Voice and Hosted VoIP. Service Description

Transcription

1 SIN 420 Issue 1.5 October 2014 Suppliers' Information Note For The BT Network BT Broadband Voice and Hosted VoIP Service Description Each SIN is the copyright of British Telecommunications plc. Reproduction of the SIN is permitted only in its entirety, to disseminate information on the BT Network within your organisation. You must not edit or amend any SIN or reproduce extracts. You must not remove BT trade marks, notices, headings or copyright markings. This document does not form a part of any contract with BT customers or suppliers. Users of this document should not rely solely on the information in this document, but should carry out their own tests to satisfy themselves that terminal equipment will work with the BT network. BT reserves the right to amend or replace any or all of the information in this document. BT shall have no liability in contract, tort or otherwise for any loss or damage, howsoever arising from use of, or reliance upon, the information in this document by any person. Due to technological limitations a very small percentage of customer interfaces may not comply with some of the individual characteristics which may be defined in this document. Publication of this Suppliers' Information Note does not give or imply any licence to any intellectual property rights belonging to British Telecommunications plc or others. It is your sole responsibility to obtain any licences, permissions or consents which may be necessary if you choose to act on the information supplied in the SIN. This SIN is available in Portable Document Format (pdf) from: Enquiries relating to this document should be directed to: sinet.helpdesk@bt.com British Telecommunications plc Registered Office 81 Newgate Street LONDON EC1A 7AJ Registered in England no

2 CONTENTS 1. INTRODUCTION SERVICE OUTLINE DIAL CODE AVAILABILITY QUALITY OF SERVICE SUPPLEMENTARY SERVICE SET SYSTEM DESCRIPTION NETWORK INTERFACE SERVICE AVAILABILITY & CONTACT POINT GLOSSARY HISTORY... 8 ANNEX A NETWORK INTERFACE CHARACTERISTICS... 9 A1 INTRODUCTION A1.1 TERMINOLOGY A1.2 VOIP ACCESS ARCHITECTURE A2 ACCESS NETWORK A2.1 PHYSICAL NETWORK A2.2 IP PROTOCOLS A3 VOICE ENCODING SUPPORT A3.1 RTP A3.2 CODECS A3.4 ECHO CANCELLATION A3.5 DTMF DIGITS AND TELEPHONY TONES A3.6 SILENCE SUPPRESSION A3.7 MIXING FOR 3-WAY AND CONFERENCE CALLS A3.8 TRANSPORT OF MEDIA A4 SIP DEVICE CONTROL A4.2 SIGNALS AND EVENTS REQUIREMENTS A4.2.1 Internationalisation A4.4 SDP A4.7 FAIL-OVER A4.8 QUARANTINE HANDLING A4.9 CAPITALISATION A4.10 DIGIT MAPS A4.12 TRANSPORT OF DEVICE CONTROL SIGNALLING A4.13 HEARTBEAT A5 PERFORMANCE CONSIDERATIONS A5.1 PACKET DELAY VARIATION A5.2 TIMING CONSIDERATIONS A6 ANNEX A REFERENCES A7 ANNEX A GLOSSARY ANNEX B SERVICE SET DESCRIPTION B1 CALLING FEATURES B1.1 CALL FORWARDING SERVICES B1.1.1 Call Forwarding on Busy SIN 420 Issue 1.5 British Telecommunications plc Page 2 of 31

3 B1.1.2 Call Forwarding on No Answer (Delayed Call Forwarding) B1.1.3 Call Forwarding Unconditional B1.1.4 Selective Call Forwarding B1.1.5 Find-me-follow-me B1.2 INCOMING CALL REJECTION SERVICES B1.2.1 Selective call rejection B1.2.2 Anonymous call rejection B1.2.3 Do not Disturb B1.3 THREE-WAY CALLING B1.4 CLI SERVICES B1.4.1 CLI presentation restriction B1.4.2 Caller Display B1.4.3 Last Caller Identity B1.4.4 Last Caller Identity Return and B1.4.5 Distinctive ringing / Call waiting tone B1.4.6 Erasure of Last Caller Identity B1.5 NETWORK MESSAGING SERVICE B1.6 SPEED DIALLING B1.7 OUTGOING CALL BARRING FEATURES B1.8 PIN CHANGE B1.9 CALL WAITING B1.9.1 Call waiting with number delivery B1.10 REMINDER CALL ALARM CALL B2 ANNEX B GLOSSARY B3 ANNEX B REFERENCES B1 CALLING FEATURES B1.1 CALL DIVERSION SERVICES B1.1.1 Call Diversion on Busy B1.1.2 Call Diversion on No Answer (Delayed Call Forwarding) B1.1.3 Call Diversion Unconditional B1.1.4 Selective Call Diversion B1.2 INCOMING CALL REJECTION SERVICES B1.2.1 Selective call rejection B1.2.2 Anonymous call rejection B1.3 THREE-WAY CALLING B1.4 CLI SERVICES B1.4.1 CLI presentation restriction B1.4.2 Caller Display B1.4.3 Last Caller Identity B1.4.4 Last Caller Identity Return B1.4.5 Distinctive ringing / Call waiting tone B1.4.6 Erasure of Last Caller Identity B1.5 NETWORK MESSAGING SERVICE B1.6 SPEED DIALLING B1.7 OUTGOING CALL BARRING FEATURES B1.8 PIN CHANGE B1.9 CALL WAITING B1.9.1 Call waiting with number delivery B1.10 REMINDER CALL ALARM CALL B2 ANNEX B GLOSSARY B3 ANNEX B REFERENCES SIN 420 Issue 1.5 British Telecommunications plc Page 3 of 31

4 1. Introduction BT Broadband Voice (BBV) and Hosted VoIP provide a telephony service using customer broadband Internet connections as the network access medium. This Suppliers Information Note (SIN) describes the customer-network interface characteristics associated with the BBV and Hosted VoIP service; it should be noted that this is a non-physical IP interface via the Internet. 2. Service Outline BBV offers up to 2 lines over a BT Business Broadband connection Hosted VoIP offers 3 to 100 lines over multiple BT Business broadband connections. Both BBV and Hosted VoIP support: Calls from BBV and Hosted VoIP customers to the PSTN / OLO Networks. Calls from the PSTN / OLO Networks to BBV and Hosted VoIP customers. Calls between BBV and Hosted VoIP customers. 2.1 Dial Code Availability BBV and Hosted VoIP support calls to the following: National numbers beginning with 01 / 02 / 03. Non-geographic numbers beginning with 05. Mobile / Pager numbers beginning with 07. Freephone, Local and National rate numbers beginning with 08. International Calls. Emergency Operator (999/112)* Operator (100) Directory Enquiries (118 xxx) Premium Rate (09) 123 access to speaking clock Missing persons Childline Samaritans 141 to withhold CLI on a per call basis 1470 to release CLI on a per call basis 144 access to BT chargecard , and to access Interactive Voice Response [IVR] menus to return the last caller s number to erase the last caller s number 1571 to access BT Answer * and # - to set up calling features. * BT recommends that End Users maintain an existing PSTN line / service for Emergency calls under power failure conditions and access to the other call types not supported by BBV and Hosted VoIP. SIN 420 Issue 1.5 British Telecommunications plc Page 4 of 31

5 Additionally, Hosted VoIP supports calls to the following numbers 2XX Extension Numbers 3XX 8XX Short Code Dialling Numbers beginning with any other digit are not supported. It is important to note that the following call types are not available: Voiceband data i.e. modem or fax BT Fault Reporting (150/151) note: BBV fault support is provided via Option Quality of Service BBV and Hosted VoIP does not guarantee the audio quality of a call, prioritisation is not given to voice packets over data packets. Congestion on the public Internet and also customer activity such as surfing or downloading files whilst making BBV and Hosted VoIP calls can impact upon the voice quality of the service. 2.3 Supplementary Service Set Annex B provides detail regarding the supplementary service set features supported by BBV and Hosted VoIP. SIN 420 Issue 1.5 British Telecommunications plc Page 5 of 31

6 3. System Description Customers will be able to connect standard telephones to a Subscriber Gateway i that will convert the analogue voice and signalling to digital packets suitable for transmission over IP connection to the Internet. Calls will be routed over the public Internet to the traditional Public Switched Telephone Network (PSTN). 4. Network Interface Customers achieve physical access to the BBV and Hosted VoIP service by connecting their CPE to their Internet access point. The VoIP interface to the BBV and Hosted VoIP service is achieved through Internet Protocol (IP) communication via the Internet; this is a non-physical interface to the BT network. Terminal equipment suppliers wishing to design CPE apparatus to interoperate with the BBV or Hosted VoIP service should refer to Annex A which describes the IP interface and provides associated technical recommendations. Detail relating to the encrypted registration process of CPE with the BBV and Hosted VoIP service is not contained within this SIN. The security-oriented nature of this aspect of detail SIN 420 Issue 1.5 British Telecommunications plc Page 6 of 31

7 is subject to a non-disclosure agreement. Terminal Equipment suppliers wishing to obtain such information should contact: Laurie Chisnell PP 1M08 Eltham SSC Merlewood House Well Hall Road, Eltham London SE9 6SF laurie.chisnell@bt.com 5. Service Availability & Contact Point For sales and marketing information about the BBV and Hosted VoIP service please contact the BT Broadband Voice Helpdesk: Tel: Option 4 SIN 420 Issue 1.5 British Telecommunications plc Page 7 of 31

8 6. Glossary ADSL BBV BT CLI IP IVR PSTN SIN Asymmetric Digital Subscriber Line Broadband Voice British Telecommunications Calling Line Identification Internet Protocol Interactive Voice Response Public Switched Telephone Network Suppliers Information Note 7. History Issue 1.0 December 2003 First Issued Issue 1.1 September 2010 Updated Issued Issue 1.3 October 2011 Amendments made clauses B1.2.2, B1.2.3 and B1.4.5 Issue 1.4 October 2013 Amendments made Section 4 Issue 1.5 October 2014 Change SINet site references from to -END- SIN 420 Issue 1.5 British Telecommunications plc Page 8 of 31

9 ANNEX A NETWORK INTERFACE CHARACTERISTICS ANNEX A CONTENTS SIN 420 Issue 1.5 British Telecommunications plc Page 9 of 31

10 A1 Introduction A1.1 Terminology This annex uses the following terms: VoIP Endpoint Business VoIP Platform This device is Customer Premises Equipment (CPE) or an IP phone or a PC running a soft client which terminates the VoIP service at the customer premises and communicates with the Business VoIP Platform via SIP signalling. The BT platform hosting Business VoIP and Hosted VoIP services. In order to function correctly with the BT network it is recommended that the following degrees of compliance be observed. This specification uses three levels for indicating the degree of compliance necessary for specific functions, procedures, or coding. They are indicated by the use of key words as follows: Requirements: Shall indicates a required function, procedures or coding necessary for compliance. In some cases shall used in text indicates a conditional requirement, since the operation described is dependent on whether or not an objective or option is chosen. Objective: Should indicates an objective which is not required for compliance, but which is considered desirable. Option: May indicates an optional operation without implying a desirability of one operation over another. That is, it identifies an operation that is allowed while still maintaining compliance. SIN 420 Issue 1.5 British Telecommunications plc Page 10 of 31

11 A1.2 VoIP Access Architecture Next-generation network architectures define the concepts of Media Gateways and Call Agents (Media Gateway Controllers). A Media Gateway converts media provided in one type of network to the format required in another type of network. A typical Subscriber Gateway provides conversion between analogue lines used to control telephone handsets and media streams from a packet network (e.g. RTP streams). Media Gateways may be capable processing audio, playing audio signals and performing media conferencing. A Call Agent or Media Gateway Controller controls the endpoints associated with each Media Gateway, including maintaining call state. For example it could instruct a Subscriber Gateway to detect off-hook and on-hook events. For the BBV and Hosted VoIP service, the BBV and Hosted VoIP switch acts as the Call Agent and uses SIP to control the Subscriber Gateway. A2 Access Network A2.1 Physical Network The BBV and Hosted VoIP service makes no assumptions on the physical connectivity to the VoIP Endpoint other than it must be a broadband link providing IP connectivity through to the BBV and Hosted VoIP switch. A2.2 IP Protocols VoIP Endpoint shall support at least the following IETF RFCs for use with the BBV and Hosted VoIP switch (other protocols may be required in addition depending on the requirements of the broadband IP link to the Subscriber Gateway e.g. DNS or DHCP): Session Initiation Protocol (RFC 3261) Internet Protocol v4 (RFC 791 [A1] ) ICMP (RFC 792 [A2] ) UDP (RFC 768 [A3] ) RTP (RFC 1889 [A4] & RFC 3551 [A5] ) SIN 420 Issue 1.5 British Telecommunications plc Page 11 of 31

12 A3 Voice Encoding Support A3.1 RTP VoIP Endpoints shall use RTP (RFC 1889 [A4] ) to encode voice packets. A3.2 Codecs BBV and Hosted VoIP switch supports the following media encodings: G.711 [A6] (A-law) G.729 A/B [A7] [A8] [A9] The BT Business VoIP Platform supports packetisation periods at the VoIP Endpoint of 5, 10, 20 or 30ms for all codecs. VoIP Endpoints shall support G.711 [A6] and may support G.729 A/B [A7] [A8] [A9]. BBV and Hosted VoIP uses the AV profile as defined in RFC 3551 [A5] Table 4. The following table reproduces the PT values for the supported codecs. Codec Encoding Name Payload Type Value G.711 A-law PCMA 8 G.729A/B G The following combinations of codec are supported: G.711 only G.711 and G.729A/B It is recommended that a VoIP Endpoint support the last option above in order to allow it to be used without modification on access links that cannot support full rate G.711 RTP encodings. The Business VoIP Platform negotiates the codec used with the VoIP Endpoint on every call. The supports RTCP (RFC 1889 [A4] ) to provide control of the RTP stream. The BBV and Hosted VoIP switch supports receipt of the following RTCP packet types: SR: Sender report, for transmission and reception statistics from participants that are active senders RR: Receiver report, for reception statistics from participants that are not active senders SDES: Source description items, including CNAME BYE: Indicates end of participation A3.4 Echo Cancellation Calls to and from VoIP Endpoint on the Business VoIP Platform will be subject to echo control in accordance with ITU-T Recommendation G.168 [10]. VoIP Endpoints shall support echo cancellation in the receive direction (i.e. cancelling echoes generated at the VoIP Endpoint s end of the call). This is also known as near end echo cancellation. Typical lengths for the echo tail required is 4 ms or less. Echo Cancellation shall be applied to all voice calls. Echo generated by the local hybrid within the VoIP Endpoint shall be cancelled. SIN 420 Issue 1.5 British Telecommunications plc Page 12 of 31

13 A3.5 DTMF Digits and Telephony Tones When using G.711 [A6] voice encoding DTMF digits and telephony tones pass in-band and no special processing is required. When using G.729 [A7] [A8] [A9] voice encoding DTMF digits and telephony tones can not pass in-band. Instead these digits, tones and signals shall be carried as RTP packets as specified in RFC 2833 [A11]. A3.6 Silence Suppression For G.711 [A6], the BBV and Hosted VoIP service does not support silence suppression. For G.729, the BBV and Hosted VoIP switch supports the built in silence suppression scheme defined by G.729 Annex B [A9]. VoIP Endpoints should support generic silence suppression/comfort noise generation for G.711 [A6]. A3.7 Mixing for 3-way and Conference Calls The Business VoIP platform provides the capability to mix 3-way and conference calls, however, there may still be a requirement for VoIP Endpoints to provide RTP mixing. A3.8 Transport of Media Media streams shall be transported using RTP as specified in RFC 1889 [A4]. Layers 1 and 2 of the protocol stack are dependent upon the physical network deployed to the end user, i.e. xdsl, cable, fixed wireless etc, which is outside the scope of this SIN. A4 SIP Device Control Business VoIP Platform switch supports SIP V2.0 as specified in RFC 3261 A4.2 Signals and Events Requirements A4.2.1 Internationalisation SIP requires the VoIP Endpoint to play most of the audible telephony tones, which vary by country or network. It is recommended that VoIP Endpoints designed for use with the BT BBV and Hosted VoIP service provide telephony interface characteristics which align with those described in the following: SIN 350 BT Public Switched Telephone Network (PSTN): Network Tones &Announcements [A14] SIN 351 BT Public Switched Telephone Network (PSTN): Technical Characteristics of the Single Analogue Line Interface [A15] Annex B of this document (SIN 420) Broadband Voice and Hosted VoIP Service Set description. SIN 227 CDS Calling Line Identification Service [A16] SIN 420 Issue 1.5 British Telecommunications plc Page 13 of 31

14 SIN 420 Issue 1.5 British Telecommunications plc Page 14 of 31

15 A4.4 SDP The BBV and Hosted VoIP switch uses SDP to provide VoIP Endpoints with the description of connection parameters such as IP addresses, UDP port, and RTP profiles. SDP shall be supported as defined in RFC 2327 [A17] and SIP V2.0 [A12] section 3.4. For the media descriptions only a subset of the defined values are supported: - Media Type audio - Transport RTP/AVP RTP using the Audio/Video profile carried over UDP. SIN 420 Issue 1.5 British Telecommunications plc Page 15 of 31

16 A4.7 Fail-over The Business VoIP Platform supports fail-over to a back-up Call Agent in the event of a failure. The back-up Call Agent will take over the old primary Call Agent s IP address and continue to control the VoIP Endpoint seamlessly. Hence no special handling for Business VoIP Platform fail-over is required in the VoIP Endpoint. A4.8 Quarantine Handling The Subscriber Gateway shall support process quarantine handling as described in section of SIPV2.0 [A12]. This is required to prevent race conditions, for example an on-hook chasing a recall key event being lost. A4.9 Capitalisation There is an inconsistency between the SIP and SDP protocols as to whether the text is casesensitive. Subscriber Gateways shall implement the following as specified by the SIP and SDP standards. All SIP commands, package names, events, signals are case insensitive. Embedded SDP descriptors are case sensitive. A4.10 Digit Maps In general the digit map used will depend upon the services enabled on each subscriber s line. For some environments the digit map may be several hundred of characters long, therefore Subscriber Gateways are required to support digit maps up to 2048 bytes as per RFC 3435 [A12]. The BBV and Hosted VoIP service set support and associated digit maps are listed in Annex B of this document (SIN420). A4.12 Transport of Device Control Signalling As the BBV and Hosted VoIP switch resides on an IP backbone the end-end protocol layers for transport of SIP or NCS device control signalling areas follows: SIP UDP IP End-to-End Protocol Stack for Transport of Device Control Signalling For Subscriber Gateways, layers 1 and 2 of the protocol stack are dependent upon the deployment, i.e. xdsl, cable, Ethernet, fixed wireless etc, which is outside the scope of this SIN. A4.13 Heartbeat Support for a heartbeat mechanism to detect Subscriber Gateways is required in order to ensure that any Network Address Translation (NAT) bindings on routers between the Subscriber Gateway and the Business VoIP Platform remain open. For example, the VoIP SIN 420 Issue 1.5 British Telecommunications plc Page 16 of 31

17 Endpoints may be an Ethernet device connected to a residential DSL router that performs NAT. The reason for this requirement is that if a NAT binding expires, there is no way for the BBV and Hosted VoIP switch to send an incoming call to the Subscriber Gateways as NAT bindings are generated via outgoing UDP packets. Using a heartbeat mechanism allows the Subscriber Gateways to detect loss of the NAT binding and recreate it if required. NAT bindings can be lost under several situations, for example a DSL uplink failure. VoIP Endpoints shall support a REGISTRATION timer of 3600s, but may re-register before this timer expires, e.g. at 75% of the expiry timer A5 Performance Considerations A5.1 Packet Delay Variation The VoIP Endpoint is required to handle a packet delay variation (PDV) of up to three times the maximum packetisation interval, for example if 30ms packetisation delay is used, the PDV needs to be up to 90ms (3 * 30ms). This setting should be configurable, or for dynamic jitter buffers the initial setting configurable. SIN 420 Issue 1.5 British Telecommunications plc Page 17 of 31

18 A5.2 Timing Considerations A Subscriber Gateway needs to derive its timing from the network. There are several methods available for deriving timing including the following: From the physical layer timing derived from the xdsl or HFC receiver interface, corrected if appropriate by Network Timing Reference information as specified by, for example, T1.413 Issue 2 [A18]. By deducing timing information that is implicit in the rate of arrival of incoming IP packets from the Business VoIP Platform. By using a Stratum 3 or higher internal clock source. A6 Annex A References [A1] IETF RFC 791 Internet Protocol, September 1981 [A2] IETF RFC 792 Internet Control Message Protocol, September 1981 [A3] IETF RFC 768 User Datagram Protocol, August 1980 [A4] IETF RFC 1889 RTP: A Transport Protocol for Real-Time Applications, January 1996 [A5] IETF RFC 3551 RTP Profile for Audio and Video Conferences with Minimal Control, July 2003 [A6] ITU-T G.711 Pulse Code Modulation (PCM) of voice frequencies [A7] ITU-T G.729 Coding of Speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear prediction (CS-ACELP) [A8] [A9] ITU-T G.729 Annex A Reduced complexity 8 kbit/s CS-ACELP speech codec ITU-T G.729 Annex B A silence compression scheme for G.729 optimised for terminals conforming to Recommendation V.70 [10] ITU-T G.168 Digital network echo cancellers [A11] IETF RFC 2833 RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals, May 2000 [A12] IETF RFC 3435 Media Gateway Control Protocol (SIP) Version 1.0, January 2003 [A13] IETF draft-foster-sip-basic-packages-10 Basic SIP Packages, February 2003 [A14] British Telecom SIN 350 BT Public Switched Telephone Network (PSTN): Network Tones and Announcements [A15] British Telecom SIN 351 BT Public Switched Telephone Network (PSTN): Technical Characteristics of the Single Analogue Line Interface [A16] British Telecom SIN 227 CDS Calling Line Identification Service [A17] IETF RFC 2327 SDP: Session Description Protocol, April 1998 [A18] ANSI T1.413 Asymmetric Digital Subscriber Line Metallic Interface For further information or copies of referenced sources, please see document sources at SIN 420 Issue 1.5 British Telecommunications plc Page 18 of 31

19 A7 Annex A Glossary ADSL ANSI AV AVP BBV BT BYE CDS CPE DHCP DNS DTMF HFC ICMP IETF IP ITU-T SIP MWD NAT NCS PDV PT RFC RR RTCP RTP SDES SDP SDSL SIN SR UDP xdsl Asymmetric Digital Subscriber Line American National Standards Institute Audio / Video Audio Video Profile Broadband Voice British Telecommunications Indicates end of participation (RTCP packet type) Caller Display Service Customer Premises Equipment Dynamic Host Control Protocol Domain Name System Dual Tone Multi-Frequency Hybrid Fibre Coax Internet Control Message Protocol Internet Engineering Task Force Internet Protocol International Telecommunication Union - Telecommunications Standardisation Sector Media Gateway Control Protocol Maximum Waiting Delay Network Address Translation Network Control Subsystem Packet Delay Variation Payload Type Request For Comments Receiver Report (RTCP packet type) Real-Time Control Protocol Real-Time Transport Protocol Source Description (RTCP packet type) Session Description Protocol Symmetric Digital Subscriber Line Suppliers Information Note Sender Report (RTCP packet type) User Datagram Protocol Any variety of Digital Subscriber Line e.g. ADSL,SDSL SIN 420 Issue 1.5 British Telecommunications plc Page 19 of 31

20 ANNEX B Service Set Description ANNEX B CONTENTS This Annex gives an outline to the service set supported by BT Broadband Voice (BBV). B1 Calling Features The following Calling Features (Supplementary Services) are available. B1.1 Call Forwarding Services B1.1.1 Call Forwarding on Busy Forwards incoming calls to a different number when the customer s number is engaged. Enable using *67* <number># Disable using #67# Status checked using *#67#. Special (interrupted) dial tone is signalled to indicate the service is active. B1.1.2 Call Forwarding on No Answer (Delayed Call Forwarding) Forwards incoming calls to a different number if the call remains unanswered for 15 seconds. Enable using *61* <number># Disable using #61#. Status checked using *#61#. Special dial tone is signalled to indicate the service is active. B1.1.3 Call Forwarding Unconditional Forwards incoming calls to a different number without alerting the diverting customer s CPE. Enable using *21* <number># Disable using #21#. Status checked using *#21#. Special dial tone is signalled to indicate the service is active. SIN 420 Issue 1.5 British Telecommunications plc Page 20 of 31

21 B1.1.4 Selective Call Forwarding Immediately forwards incoming calls from selected calling numbers. (The circumstances in which incoming calls from these numbers are forwarded depends upon the configuration of unconditional, busy and delay call forwarding.) The service is accessed using to enter an Interactive Voice Response [IVR] menu. To configure the service through the customer s CPE: - the Selective Call Forwarding access code is an announcement is returned indicating the current status of the service further announcements prompt the customer for different options including: turning the service on and off adding entries to the list of selected numbers (including the last calling number) removing one or more entries from the list of forwarded numbers reviewing the list of currently forwarded numbers It is possible to reject the previous calling number, even if the number was withheld. At no time is the number revealed in the menu system (for example there are announcements such as the service is active and there are two anonymous entries on the list ). The IVR menu has the following DTMF digit options: 0 for instructions 08 to delete all 09 to delete all anon 1 for list review 07 to remove number during list review * to remove a number # to add a number 3 to turn on or off Remote access to call forwarding is not available. B1.1.5 Find-me-follow-me Forwards Incoming Calls by ringing several numbers based on rules set up via on-line portal. To activate/deactivate the service through the customers CPE: Activate Find-me-follow-me *371# Deactivate Find-me-follow-me #371# SIN 420 Issue 1.5 British Telecommunications plc Page 21 of 31

22 B1.2 Incoming Call Rejection Services A received call can originate either from the PSTN or from another BT Broadband Voice customer. B1.2.1 Selective call rejection The service consists of a list of numbers, calls from which are rejected with an announcement. To configure the service through the customers CPE: Access code The menu system is then similar to that used for Selective Call Forwarding. B1.2.2 Anonymous call rejection Allows the automatic rejection of all calls where a caller has actively withheld their number. [This will not reject calls where the caller cannot send a CLI e.g. some international] Enable with *227# Disable with #227# Check status with *#227# B1.2.3 Do not Disturb To configure the service through the customers CPE: Enable with *261# Disable with #261# Check status with *#261# B1.3 Three-way Calling Allows a customer to add a third party to a call. The called parties can be either other BT Broadband Voice/Hosted VoIP customers or PSTN customers. Once the initial call is established between party A (BBV or Hosted VoIP customer) and party B, signalling Recall gives dial tone and allows an enquiry call to be made to party C. Party A can then either clear down and be re-connected to the original A B call or signal Recall again to convert the call into a full three-party call. A further Recall signal will then release the connection to party C and return to the original A B call. Party A clearing the three-way call will clear down all connections except where party B is on hold in which case party B is reconnected to A. SIN 420 Issue 1.5 British Telecommunications plc Page 22 of 31

23 B1.4 CLI Services A customer s line shall have a network number. Under normal usage this number is passed forward in a call and presented to the called party where appropriate equipment and service is available. Under the CLI Code of Practice, a caller is able to have this number restricted from being presented to the called party and thereby remain anonymous. The following subclauses describe the various set-ups and controls a caller may have regarding the release of their number, or Call Line Identity (CLI), and also services/features that use a caller s CLI. SIN 420 Issue 1.5 British Telecommunications plc Page 23 of 31

24 B1.4.1 CLI presentation restriction BT Broadband Voice and Hosted VoIP customers will have their CLIs released by default. If CLI needs to be restricted on a particular call then the called number needs to be prefixed with the digits 141. B1.4.2 Caller Display The ability to see the identity of a caller will be dependent on the capabilities of the Subscriber Gateway equipment and other associated customer CPE. The BT Broadband Voice network will signal towards the Subscriber Gateway to allow the Subscriber Gateway to reproduce a service for the customer which is similar to the BT Caller Display service described in SIN 227 [B1]. To configure the service through the customers CPE: Display the Caller`s Identity *234# Do not display the Caller`s Identity #234# Check if CPE set to display Caller`s Identity *#234# B1.4.3 Last Caller Identity The service allows the customer to hear the last calling party s number. Access code 1471 will return an announcement detailing the number of the last calling party (if available). B1.4.4 Last Caller Identity Return and Signalling 3 after 1471 will return the call to the last calling party (if available). Signalling 4 after 1471 will return the call to the last calling party (if available) without the voice announcement.. B1.4.5 Distinctive ringing / Call waiting tone Allows customers to have a distinctive ring cadence for selected incoming calls based on the CLI received. The service consists of a list of phone numbers that the customer constructs. Calls where the CLI matches a number in the list will cause the distinctive ringing cadence or where call waiting is activated produce a distinctive call waiting tone. To configure the service through the customers CPE: Access code The menu system is then similar to that used for Selective Call Forwarding B1.4.6 Erasure of Last Caller Identity This service erases the last number stored by Last Caller Identity (1471). SIN 420 Issue 1.5 British Telecommunications plc Page 24 of 31

25 To configure the service through the CPE: Access code 1475 is signalled An announcement will confirm erasure of the last number stored SIN 420 Issue 1.5 British Telecommunications plc Page 25 of 31

26 B1.5 Network Messaging Service Allows customers to redirect unanswered or busy calls to a voic server. Signalling 1571 connects the customer to the BT Answer 1571 service. To configure, follow the voice prompts. BT Broadband Voice and Hosted VoIP does not support the use of Special (interrupted) dial tone to signify a message waiting on BT Answer Instead customers are suggested to check the service on a regular basis to avoid missing any stored messages. B1.6 Speed Dialling Speed Dialling consists of a set of mappings of two digit codes to telephone numbers. BBV and Hosted VoIP allows storing of up to 50 speed dialling number maps in the range 00 through to 49: Signalling ** followed by the two digit speed calling code is interpreted by the BT Network as the full number code that the speed calling code is mapped to. Speed dialling is enabled by default. To enable speed calling codes: Access code *51* Announcements prompt the customer to enter the speed code and the number to map to followed by * / # An announcement confirms the mapping is enabled To disable speed calling codes: Access code #51* Announcements will prompt the customer to enter the speed code to disable An announcement will confirm the mapping is no longer in use SIN 420 Issue 1.5 British Telecommunications plc Page 26 of 31

27 To check speed calling codes: Access code *#51* Announcements will prompt the customer to enter the speed code to check An announcement will confirm the current speed code mapping B1.7 Outgoing Call Barring Features These are features available to a customer to restrict a BBV or Hosted VoIP line to a subset of the full dialling plans e.g. to bar outgoing calls to International & Mobile numbers. The classes that can be barred are: Note: Almost all calls [All except the disbarring number #341*] International calls National and mobile calls Calls to access codes [All access codes except the disbarring number: #345*] National and mobile calls are always barred together, that is either both are barred or neither is barred Access code barring does not include barring of the access codes to check the barring status and to turn off access code barring To activate barring to a group of classes of numbers through the CPE: Access codes to activate barring of each of the following groups of classes of numbers are: Almost all calls *341#. National, International and mobile calls *342#. International calls *343#. Operator Calls *344#. Calls to access codes *345#. Premium Rate Numbers *347#. Signal the required access code An announcement confirms the activation SIN 420 Issue 1.5 British Telecommunications plc Page 27 of 31

28 To deactivate barring to a group of classes of numbers through the CPE: Access codes to deactivate barring of each of the following groups of classes of numbers are - Almost all calls #341*. National, International and mobile calls #342*. International calls #343*. Operator calls #344*. Calls to access codes #345*. Premium Rate Numbers #347#. Signal the required access code An announcement prompts the customer to enter their PIN code The customer enters their PIN code An announcement confirms the deactivation To check the barring status through the CPE: Access code *#34# An announcement lists the classes of numbers that are barred B1.8 Pin Change PIN Change allows a customer to alter their Personal Identification Number (PIN). The PIN is used to enable secure access to certain services, such as Outgoing Call Barring. Customers are permitted to change their PIN to any four-digit number. To change the PIN from the CPE: Access code *68* An announcement prompts the customer to enter their current PIN The current PIN is entered An announcement prompts the customer to enter a new 4-digit PIN The new PIN is entered An announcement confirms the new PIN SIN 420 Issue 1.5 British Telecommunications plc Page 28 of 31

29 B1.9 Call Waiting Call Waiting (CW) is the service that notifies a customer engaged on a call that another caller is attempting to call them. The service allows the customer to accept the new incoming call and shuttle between the two calls. The service is available to all BBV and Hosted VoIP customers to enable. Where CW is invoked, the called party is notified by an in-band tone when a call is waiting, the calling party will receive an announcement telling them that the system has alerted the called customer. The BBV and Hosted VoIP customer can switch between the current call and the new call using the Recall signal. CW is enabled using *43# CW is disabled using #43# CW status is checked using *#43# B1.9.1 Call waiting with number delivery Where Call Waiting has been enabled and a second call arrives, the BT Network will apply the call waiting indication tone and deliver the CLI of the caller. The ability of the BBV and Hosted VoIP customer to see the identity of the second caller will be dependent on the capabilities of the Subscriber Gateway equipment and other associated customer CPE (see sub-clause B1.4.2). B1.10 Reminder Call alarm call This service allows a customer to be called by the BT Network at a requested time and to hear an announcement when the call is answered. Reminder calls are made within 1 minute of the requested time. If the reminder call is not answered, the service will retry later. Reasons for the reminder call not being answered include resource failure, the customer being engaged, and the customer not answering. The service will make up to 3 retries with an interval of 2 minutes between each attempt. Reminder calls can be for an individual reminder or regular reminders. Individual reminders are made once in the 24 hours after the reminder was requested. Regular reminders can be made according to the configured repeat option. The options are every Monday (1), Tuesday (2) to every Sunday (7) or every weekday (8) and every day (9). SIN 420 Issue 1.5 British Telecommunications plc Page 29 of 31

30 Reminder call access codes are: Enable an individual reminder *55* Disable all individual reminders #55# Disable one individual reminder #55* Check individual reminders *#55# Enable a regular reminder *56* Disable all regular reminders #56# Disable one regular reminder #56* Check regular reminders *#56# Configuration of the service through CPE is achieved by signalling one of the 8 access codes shown above. To enable a regular reminder call: Signal the access code An announcement will prompt input of the desired time followed by * An announcement will prompt input of the repeat option code 1 9(see above) followed by # An announcement confirms the reminder is set, giving the option to cancel. To enable an individual reminder, the time is followed by # (not *) and no repeat code is requested. To disable all or check individual or regular reminders, the customer inputs the appropriate access code and will hear an appropriate announcement. To disable one individual or regular reminder, the customer inputs the appropriate access code then proceeds as described for enabling reminders. It will not be possible to configure conflicting regular reminders. Regular reminders conflict if they are set for the same time and their repeat options have a day in common. SIN 420 Issue 1.5 British Telecommunications plc Page 30 of 31

31 B2 Annex B Glossary BBV BT CDS CLI CPE CW DTMF IVR PIN PSTN Broadband Voice British Telecommunications Caller Display Service Calling Line Identification Customer Premises Equipment Call Waiting Dual Tone Multi-Frequency Interactive Voice Response Personal Identification Number Public Switched Telephone Network B3 Annex B References [B1] British Telecom SIN 227 CDS Calling Line Identification Service For further information or copies of referenced sources, please see document sources at SIN 420 Issue 1.5 British Telecommunications plc Page 31 of 31