GB2479189A

GB2479189A - A computer terminal controlling through a computer-telephony controller operation of first and second communication terminals using the same label value.

Info

Publication number: GB2479189A
Application number: GB1005546A
Authority: GB
Inventors: Jon Booton
Original assignee: British Telecommunications PLC
Current assignee: British Telecommunications PLC
Priority date: 2010-04-01
Filing date: 2010-04-01
Publication date: 2011-10-05
Also published as: GB201005546D0

Abstract

A call control system for provisioning computer-telephony events, in which the events comprise a computer terminal controlling through a computer-telephony (CTI) controller at different times operation of different ones of a plurality of communication terminals. The computer-telephony controller receives from the computer terminal a request incorporating a label value for a computer-telephony event. The computer-telephony controller refers to a first mapping in which the label value is mapped to an identifier of a first communication terminal and initiates the requested computer-telephony event controlling operation of the first communication terminal. A second mapping accessible by the computer-telephony controller is created in which the label value is mapped to an identifier of a second communication terminal while leaving unchanged the label value stored at the computer terminal. Following creation of the second mapping, the computer-telephony controller receives from the computer terminal a request incorporating the label value for a computer-telephony event and initiates the requested computer-telephony event controlling operation of the second communication terminal. The user can at different times initiate computer-telephony events involving different ones of the plurality of communication terminals by issuing requests incorporating the same label value.

Description

Computer Telephony

Introduction

This invention relates to computer-telephony integration (CTI) and to a system and method providing for control of communications terminals in a computer-telephony system.

Computer-telephony allows a user to control, from their networked computer terminal, telephony activity related to a telephony terminal nominated by the user: typically the telephone on their desk. The kind of telephony activity controlled in this way typically includes the initiation of calls from the telephone and the logging of calls to and from the telephone (i.e. allowing the user to redial outgoing calls or to respond to missed calls).

European patent 1068717 in the name of British Telecommunications plc discloses a method of registering the identity of a communications terminal in association with the identity of a computer terminal, the method comprising the steps of: providing to a user of the computer terminal, via the computer terminal, the identity of a predetermined destination terminal number; answering a call made to the predetermined destination terminal number; receiving at the predetermined destination terminal number the identity of a communications terminal from which the call was made; providing to the user, via the computer terminal, a codeword; receiving, at the predetermined destination terminal, data provided by the user via the telephone terminal; comparing the received data with the provided codeword; and if there is a match, registering the identity of the communications terminal in association with the identity of the computer terminal.

One possible arrangement for changing the phone controlled by the user via a CTI system is shown in Figure 1. Figure 1 shows a user (represented as user 1A) operating computer terminal 2A to control a first phone 3 via CTI server 10. Figure 1 also shows the same user (now as user 1 B) using the computer terminal (now shown as 2B) to control second phone 33 via the same CTI server 10. It will be appreciated that user 1A and user lB represent the same user at different times and computer terminal 2A and computer terminal 2B represent the same computer terminal at equal different times. In order to take computer-telephony control of first phone 3, user 1A has to first register with CII server 10, as described, above. Upon successful registration, a server label (not shown) is created on CTI server 10 and a client label (not shown), i.e. a client version of the server label, is provided to the user on computer terminal 2A. For call control requests sent by the user foflowing registration, if the computer-telephony control request includes the client label, OTt server 10 can verify the label against the server label and obtain the appropriate phone CU for phone 3. CTI server 10 is then able to implement the user's request to control the user's phone 3.

If user 1A remotely controlling first phone 3 now wishes to change the phone they remotely control via CTI server 10 from first phone 3 to second phone 33, the user needs to repeat the registration process but using the new phone they now wish to control -i.e. second phone 33. The new registration therefore involves, with reference to Figure 1, user 1B, computer terminal 2B and phone 33. Upon successful re-registration, a new server label (not shown) is created on CTI server 10 and a new client label (not shown), i.e. a client version of the new server label, is provided to the user on computer terminal 2B. For call control requests sent by the user following the change of registration, if the computer-telephony control request includes the new client label, CTI server 10 can verify the label against the new server label and obtain the appropriate phone CLI for phone 33.

CTI server 10 is then able to implement the user's request to control the user's new phone 33.

This arrangement is cumbersome and time-consuming in that it requires the user to repeat the complete original registration process any time they wish to control a new phone.

The invention provides a method of initiating, in a call control system, computer-telephony events; in which the call control system comprises a computer-telephony controller and a plurality of communication terminals; in which the computer-telephony events comprise a computer terminal controlling through the computer-telephony controller at different times operation of different ones of the plurality of communication terminals, in which the method comprises: receiving at the computer-telephony controller from the computer terminal a request incorporating a label value for a computer-telephony event; referring to a first mapping accessible by the computer-telephony controller in which the label value is mapped to an identifier of a first communication terminal and initiating the requested computer-telephony event controlling operation of the first communication terminal; creating a second mapping accessible by the computer-telephony controller in which the label value is mapped to an identifier of a second communication terminal while leaving unchanged the label value stored at the computer terminal; and following creation of the second mapping, receiving at the computer-telephony controller from the computer terminal a request incorporating the label value for a computer-telephony event and initiating the requested computer-telephony event controlling operation of the second communication terminal.

Advantageously, the user can at different times initiate computer-telephony events involving different ones of the plurality of communication terminals by issuing requests incorporating the same label value. Hence there is no need to change the label stored on the user's computer.

According to an aspect of the invention, the method further comprises receiving from the computer terminal a mapping change request and creating the second mapping in response to the mapping change request.

According to a further aspect of the invention, the second mapping overwrites the first mapping. According to a further aspect, the label value identifies one of an individual user, a group of users and a type of user, in which the one of the individual user, the group of user and the type of user identified by the label value is authorised to control the different ones of the plurality of phones.

According to an aspect of the invention, the method further comprises providing the computer terminal with a list of communication terminal identifiers to which the label value has previously been mapped; and allowing re-establishment of a previous mapping.

The invention further provides a call control system for initiating computer-telephony events; in which the computer-telephony events comprise a computer terminal controlling through a computer-telephony controller at different times operation of different ones of a plurality of communication terminals, in which the call control system comprises a computer-telephony controller and a plurality of communication terminals; in which the call control system comprises a store, accessible by the computer-telephony controller, for storing a label value in association with an identifier of ones of a plurality of communications terminals; in which the computer-telephony controller comprises an interface for receiving from the computer terminal requests incorporating the label value for computer-telephony events; in which the computer-telephony controller comprises a processor configured to receive from the first computer terminal a request for a first computer-telephony event; to refer to the store and retrieve the identifier of a first communication terminal and to initiate the requested first computer-telephony event controlling operation of the first communication terminal; in which the processor is configured to create an association in the store between the label value and an identifier of a second communication terminal while leaving unchanged the label value stored at the computer terminal; and in which the processor is configured, following creation of the association between the label value and the identifier of a second communication terminal, to receive from the computer terminal a request incorporating the label value for a second computer-telephony event and to initiate the requested second computer-telephony event controlling operation of the second communication terminal.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 shows schematically aspects of a basic computer-telephony system; Figures 2 to 4 show schematically various aspects of a computer-telephony system according to the invention.

Embodiments of the invention will now be described to illustrate how the invention provides an improved method of initiating computer-telephony actions by a user from a computer terminal and controlling through a call control system at different times, operation of different communication terminals (e.g. phones). The improved method establishes in the call control system a mapping between a label and an identifier of a first phone and the same label is provided to the computer terminal. The user can now issue requests to the call control system incorporating the label for a computer-telephony action involving controlling the actions of the first phone. If the user wished to change the phone over which they have control, the user issues to the call control system an association change request to remove a first association between the first phone and the user and to establish a second association between a second phone and the user. On the basis of the association change request, the mapping in the call control system is edited to map the label to an identifier of the second phone. Following creation of the edited mapping, the user can now issue requests incorporating the same label for a computer-telephony event controlling the actions of the second phone.

A user need only register once to generate a label to use the CTI service to control a plurality of phones. There is now only one CTI label per user. The user's client-side label does not change if the phone changes -only the phone information relating to the corresponding label in the mapping is altered. Optionally, a history is maintained of previously registered phones associated with the user to allow the user to simply re-take control.

According to the invention, a user registers only once to generate and receive a client label for use in supporting computer-telephony control requests to CII server 10. Figure 2 shows user 1 who wishes to control remotely a phone 3 using their computer 2. This can be achieved by using computer applications running on computer terminal 2 that interact with a CII (Computer-telephony Integration) server 10. In order to achieve this, a user proves their identity to the CTI server and proves that they have access to the phone they wish to control.

When a user attempts to use the computer-telephony control service for the first time (or for the first time since their association with the target phone has been revoked) they will need to obtain a label. This procedure is known as user registration. Initial Registration, according to which a user 1 gains access to computer-telephony control allowing the user to use computer terminal 2 to control phone 3, will now be described with reference to Figures 2.

User registration User registration is comprised of two operations. The first operation involves the user navigating to a web page hosted on a web server (registration server 12) hosted on CII server 10. On this web page they enter user credentials to prove their identity. If the credentials are successfully verified (e.g. by checking with corporate directory 14, such as Microsoft Active Directory) the user receives, from registration server 12 for display on the user's computer 2, a contact number for an IVR system hosted by Soft PBX 16 on CTI server 10 and a numerical code or codeword, which is required for the second operation.

The second operation requires the user to call from the phone 3 they wish to control, via the connected PBX 4 and voice network 6, into the IVA service provided by soft PBX 16.

The IVR service captures the identity of the phone 3, for example by monitoring the CLI (Calling Line Identifier) of the phone 3 and prompts (i.e. by voice prompt) user 1 to enter on phone 3 the codeword they received through the web page in the first operation.

When the user has entered the codeword to the IVR service, the details provided are checked. If a codeword entered by the user is detected that matches what was presented on the web page, CII server 10 knows that the user has access to the computer 2 and the phone 3 and the registration server creates a server label record (25 in Figure 3).

Otherwise, user registration is terminated. On successful registration, registration server 12 stores the label in server label record 25 and also copies a client label (described later) to user computer terminal 2, typically to a web browser, although other forms of fat client could also be used.

CTI server 10 also comprises telephony server 21, which acts to capture, via PBX driver and data network 8, CTI events from user's PBX 4. To clarify further, CTI server 10 has knowledge of several PBX systems (not shown) via data network 8 (e.g. an IP network). In order to provide to a user computer-telephony control of phone 3, CII server needs to know which PBX phone 3 is connected to. When a user activates the phone to contact the WA system during the second operation of registration, a log of this particular event is sent from connected PBX 4 to PBX Driver 20 on CTI server 10, via data network 8. In this way, CTJ server 10 knows from the event received from PBX 4, that the user's phone 3 is connected to PBX 4. For call control requests sent by the user following successful registration, CTI server 10 can exercise control via data network 8 of the correct PBX (i.e., in this case, PBX 4), in order to control the user's phone 3.

According to the invention, a user registers only once to receive a client label for use in supporting computer-telephony control requests to CTI server 10. The same client label is stored persistently and maintained every time the user switches control to a different phone. The user would typically register their primary-use phone initially but is free to amend the registration to switch control to another phone that the user has access to.

Only one client label is required per user, irrespective of the number of changes of computer-telephony controlled phone which may be requested and implemented. Equally, only one server label record 25 is required per user, irrespective of the number of changes of computer-telephony controlled phone which may be requested and implemented. If the phone controlled via CTI server 10 changes, only the phone identifier information in server label record 25 in database 18 need be altered, the client label va'ue held on user's computer terminal 2 does not change.

Database Figure 3 shows, among other things, a detailed view of database 18 relating to CTI server 10 of Figure 2 and the various records that may be stored there. In particular, Figure 2 shows a set of records relating to phone 3. Database 18 is accessible by CII server 10 and is preferably co-located with it but may be hosted on a separate server (not shown), if more convenient. Phone number record 26 comprises a phone identifier (e.g. at least one of CLI and DN) and PBX identifier relating to phone 3 and derived by the IVR service and telephony server 21 during registration of phone 3. Optionally, registration record 28 and history record 30 (described in more detail, below) are also provided.

As shown in Figure 3, server label record 25, stored in database 18, contains the following information: * Unique value -(Value) a randomly generated number that is unique for each label (e.g. 123456789).

* Phone CLI -(CLI) the caller ID that the phone presents when in call activity (e.g. 100100). Server label record 22 derives the CLI field from phone number record 26 described above * Phone DN -(not shown) the Directory Number as known by the PBX it belongs to.

This is derived from the data received from PBX 4 by telephony server 21.

* PBX ID -the identity of the PBX the phone is connected to. This is similarly derived from the data received from PBX 4 by telephony server 21.

* User ID -a unique identifier that identifies the user. It is captured at registration time during the credential entry stage (and verified by external source 14: e.g. corporate directory); the unique identifier may function to identify an individual user, a group of users or a type of user, authorised to control the phone.

* Status -(not shown) a numeric code that indicates the status of the label e.g. 0 would mean OK and 7 would mean that the label has been cancelled, rendered inactive or is otherwise unusable.

The client label (not shown) stored persistently on user computer terminal 2 contains only domain information (e.g. a URL) to identify correct registration server 12 and the unique value (Value). This makes the data anonymous at the user end (i.e. it contains no indication of the identity of the phone being controlled) so countering fraudulent use.

User registration messages At this stage, user 1 has a persistent "label-for-life" stored on their computer terminal 2 for control of phone 3 (e.g. the user's primary office phone). The next section details how the label-for-life model provides a way for users to quickly register a new phone whilst keeping the same label.

The web browser now includes the client label when initiating computer-telephony control S requests invoking the URL of Registration server 12. The client label is unique to the user and will stay with them throughout the duration of service. The client label forms part of each subsequent computer-telephony control request sent to CTI server 10 from the web browser running on user's computer 2. The client label is included with the requests in order to confirm the user's identity from which the identity of phone 3 (e.g. the CLI of the phone) the user is authorised to control via the CTI system is retrieved from server label record 25 in database 18. Note that server label record 25 is indexed for this operation by unique label value, (Value) and not user identity (which could more easily be faked).

We now describe in more detail the registration process. As indicated, above, in order to initiate registration with CTI server 10, the user navigates to CTI server 10 (or more accurately, registration server 12 hosted on CTI server 10). Registration server 12 serves a welcome page from which the user clicks on a link to request a check of their registration. The web browser responds to the user selecting the link by sending to registration server 12 a request of the form: "GET/registration/check. html HTTP/1. 1 Host: www. cti-server. corn Label: name= Accept: */* Upon receiving this request, registration server 12 will note that no client label is present in the request (i.e. the label name field is empty). In response to this request, registration server 12 will return a page to the user asking him or her to identify him or herself.

Authentication of the user will normally be desirable but is not essential in all implementations. Proof of user identity may be achieved in a number of ways, including based on recognising the network connection over which a request is received in a secure network. One way of proving user identity is for the user to enter a unique identifier (such as a user ID) and a password. Registration server 12 then checks these credentials against an authentication authority, typically an external repository such as corporate directory 14. If the credentials are accepted by registration server 12, e.g. registration server 12 finds the credentials supplied match the relevant records of the corporate directory, the user is authenticated. On successful registration, CTI server 10 creates server label record 25. Alternatively, CTI server 10 uses the unique identifier (User ID) provided by the user at the identification stage to locate the appropriate server label record 25 already existing in database 18. Once the appropriate server label record 25 has been found, CTI server 10 creates a new client label using the unique label value (Value) found in database label record 25. In either case, CTI server 10 passes the client label to the browser on computer terminal 2 through registration server 12, as illustrated, below: "HTTP/1. 1200 OK Content-type: text/html Set-Label: name=value (content of page)" Where the user has already registered with registration server 12 using the new computer terminal, the appropriate label will be included in the request sent to registration server 12 and registration server 12 will serve a different page in response based on successfully finding the label in database 18. The different page served by registration server 12 would confirm to the user who they are and what phone they are currently controlling.

Computer-telephony control The user can now issue requests comprising the client label for computer-telephony control of phone 3 from computer terminal 2. Continuing the above illustration, the next time a user initiates a computer-telephony request from computer terminal 2, the browser on computer terminal 2 will include in the request a copy of the client label, as follows: "GET/ca///makecall.mp 123 HTTP/1. 1 I-lost: www.cti-server.com Label: name_-value Accept: */*$ On finding the label in the request, CTI server 10 refers to the mapping and initiates the requested computer-telephony control of phone 3. In more detail, CII server 10 extracts the client label from the request and uses the label Value field to create a database query.

The database query searches for the server label record based on the label value. The query will only return one record -the record having the appropriate Value and CLI fields.

When the label record is found, CTI server 10 extracts the phone identifier (e.g. CLI field) identifying the phone the user is configured to control (i.e. phone 3) and initiates the CII request based on this information.

New Registration Registration of a new phone according to the invention is also illustrated in Figure 3. If a user wishes to control from their computer terminal a phone 33 that they have not used before, the user will need to call the IVR service using the new phone 33 to prove their identity (i.e. a similar operation as for original registration, described above: providing via the new phone 33 a new codeword obtained by the user via their web browser from registration server 12 with which the user has authenticated). On receipt of call, the IVR service automatically detects the CLI of new phone 33 and, upon successful identification of the user (i.e. receipt of the correct codeword), alters the CLI field in the user's records in database 18 (primarily, server label record 25) to that of the new phone 33. The client label does not change as a result of the change in phone.

Re-registration.

Re-registration of a phone, previously controlled by the user is also illustrated in Figure 3.

If a user wishes to revert to control from their computer terminal a phone 43 they have controlled from their computer terminal before (but are not currently controlling), the user can, according to a preferred embodiment, use a new function supported by CTI server 10 and accessible via the web page served by registration server 12. According to this preferred embodiment, CII server 10 stores, in history record 30 of database 18, details of phones previously registered with it for computer-telephony control by user 1 and displays the history to the user on request. Preferably history record 30 stores in database 18 a history, typically indexed by CLI, of phones previously associated, by means of server label record 25, with user 1. History record 30 comprises a list of CLIs of previously registered phones and a user identity field. The user is then able to select from the CLI list in the history record 30, a phone whose CLI is recorded against the user's identity that the user wishes to re-take control of. The selected CLI is then included in the server label record 25, replacing the CLI of the currently registered phone. The client label held on user's computer terminal 2 and the label value field (Value) of server label record 25 do not change. This advantageously avoids completely the above-described registration procedure, whilst maintaining security, by exploiting the fact that the user has previously proven they are allowed to control a phone they have previously controlled from their computer terminal.

It may be preferred not to extend the history feature to all phones. According to a further refinement, CII server 10 is made aware if a phone is situated in a free-access area, such as on a hot desk. According to this refinement, CTI server 10 deletes the relevant association record from the history at the end of the day on which the phone was registered, thus forcing the user to prove they have control of the phone on any given day.

According to a further embodiment, history record 30 can be edited or deleted. If, for example, a user no longer wishes to be able to control from their computer terminal a phone (e.g. a hot desk phone) they have controlled from their computer terminal before and which has an entry in their history, the user (or an administrator) can remove from the user's history the entry relating to that phone or, if desired, remove from database 18 the whole of history record 30, referenced by the user's identity information.

According to an alternative embodiment, the IVR service could be provided by an application 40 such as a call routing server or a customer relationship management (CAM) application connected to OTt server 10 via a software development kit (SDK) 42.

Application 40 could comprise BT Harrier Call Router as the Call Routing Server or one of the CRM applications provided by Oracle. The Call Routing Server is responsible for providing inbound call routing to a user's preferred end device (phone). An exemplary practical implementation of the invention might use BT iBridge as the CTI Server.

A typical architecture for a computer terminal or server on which software implementing the invention can be run, is shown in Figure 4. Each computer apparatus comprises a central processing unit (CPU) 110 for executing computer apparatus programs and managing and controlling the operation of the computer apparatus. The CPU 110 is connected to a number of devices via a bus 111 to a variety of devices including non volatile data storage means. The non volatile data storage means may comprise one or more hard disc drives 120; in addition there may be provided removable non volatile data storage means 113, such as removable hard disc drives or optical media (for example re-writable or recordable DVDs) and solid state memory devices including non-volatile ROM 114 and volatile RAM 115.

The computer apparatus further includes one or more network card 116 (one shown) for interfacing to and exchanging data via one or more network (not shown) such as an IP network underpinning the various connections shown in Figures 1 to 3. The network interface(s), e.g. Ethernet, may be a local area network (LAN) adaptor connecting to a LAN. The LAN may itself be connected to other LANs and wide area networks (WANs) to enable the apparatus to communicate with and exchange data with other computer apparatuses. Alternatively, the network interface may be a DSL modem, or similar, that provides a connection to a WAN, such as the internet or an intranet, which enables communications with further networks.

The computer apparatus can also include user input/output devices such as a mouse 117 and keyboard 118 connected to the bus 111 via input/output port 119, as well as a display 112. The computer apparatus is powered by power supply unit 130, typically obtaining power from an external power grid or internal battery (not shown). The skilled person will understand that this architecture is not limiting, but is merely an example of typical computer apparatus architecture. The computer apparatus may also be a distributed system, comprising a number of computer apparatuses communicating through their respective interface ports 116 such that a user may access program and other data stored on a remote computer apparatus using user input/output devices 112, 117, 118 on their local computer apparatus.

Non volatile data storage means 120 comprises an operating system 122 and one or more application programs 124. Operating system 122 comprises the software that the computing apparatus requires to operate, communicate with other computer apparatuses, receive input from users, display outputs and results to users, etc. Application programs 124 can be executed by the apparatus in order to provide additional functionality. Non volatile data storage means 120 further comprises computer apparatus code 126 which can be executed in order to perform a method according to the present invention, for example such as the one described above and illustrated in the drawings. It will be understood that computer apparatus code 126 may comprise a single integrated application, or a number of different modules that are accessed separately to execute a method according to the present invention. Each module may perform the functionality of one or more of the processes which comprise the present invention.

As will be understood by those skilled in the art, the invention may be implemented in computer program product software, any or all of which may be contained on various storage media so that the program can be loaded onto one or more computing devices (such as shown in Figure 4) or could be downloaded over a computer network using a suitable transmission medium. The computer program product software used to implement the invention may be embodied on any suitable carrier, readable by a suitable computer input device (not shown), such computer program product comprising optically, magnetically or otherwise readable marks.

The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of another of the embodiments, or any combination of the embodiments. Further embodiments of the invention are envisaged and will be evident to the skilled reader. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

The invention may be implemented with any form of label comprising the Value field which is stored persistently on the user's computer terminal and allows the user to include it in computer-telephony control requests as a means of referring to a corresponding label mapped in a mapping accessible to the CTI sever to the identify of the phone to be controlled. Although described above in terms of a CTI server, the invention may be implemented with any form of call control system which interfaces with the user's computer terminal and phone to support user registration and call control, the issuing of a client label, mapping the client label to a phone identifier and call control instigated by a request received from the user's computer terminal. Server label record 25 and other records of database 18 may be stored at a different server to CTI server 10 or at another location to which CTI server 10 has access.

Claims

CLAIMS1. A method of initiating, in a call control system, computer-telephony events; in which the call control system comprises a computer-telephony controller and a plurality of communication terminals; in which the computer-telephony events comprise a computer terminal controlling through the computer-telephony controller at different times operation of different ones of the plurality of communication terminals, in which the method comprises: receiving at the computer-telephony controller from the computer terminal a request incorporating a label value for a computer-telephony event; referring to a first mapping accessible by the computer-telephony controller in which the label value is mapped to an identifier of a first communication terminal and initiating the requested computer-telephony event controlling operation of the first communication terminal; creating a second mapping accessible by the computer-telephony controller in which the label value is mapped to an identifier of a second communication terminal while leaving unchanged the label value stored at the computer terminal; and following creation of the second mapping, receiving at the computer-telephony controller from the computer terminal a request incorporating the label value for a computer-telephony event and initiating the requested computer-telephony event controlling operation of the second communication terminal.
2. A method as claimed in claim 1 further comprising receiving from the computer terminal a mapping change request and creating the second mapping in response to the mapping change request.
3. A method as claimed in any above claim in which the second mapping overwrites the first mapping.
4. A method as claimed in any above claim, in which the label value identifies one of an individual user, a group of users and a type of user, in which the one of the individual user, the group of user and the type of user identified by the label value is authorised to control the different ones of the plurality of phones.
5. A method as claimed in any above claim further comprising providing the computer terminal with a list of communication terminal identifiers to which the label value has previously been mapped; and allowing re-establishment of a previous mapping.
6. A call control system for initiating computer-telephony events; in which the computer-telephony events comprise a computer terminal controlling through a computer-telephony controller at different times operation of different ones of a plurality of communication terminals, in which the call control system comprises a computer-telephony controller and a plurality of communication terminals; in which the call control system comprises a store, accessible by the computer-telephony controller, for storing a label value in association with an identifier of ones of a plurality of communications terminals; in which the computer-telephony controller comprises an interface for receiving from the computer terminal requests incorporating the label value for computer-telephony events; in which the computer-telephony controller comprises a processor configured to receive from the first computer terminal a request for a first computer-telephony event; to refer to the store and retrieve the identifier of a first communication terminal and to initiate the requested first computer-telephony event controlling operation of the first communication terminal; in which the processor is configured to create an association in the store between the label value and an identifier of a second communication terminal while leaving unchanged the label value stored at the computer terminal; and in which the processor is configured, following creation of the association between the label value and the identifier of a second communication terminal, to receive from the computer terminal a request incorporating the label value for a second computer-telephony event and to initiate the requested second computer-telephony event controlling operation of the second communication terminal.