Abstract:
A caller identification callback list method and system. The system displays a callback list informing a user of a missed call received from a terminal on a central office telephone line from within an organization. The callback list includes the names and extension or branch telephone numbers for persons the user has defined exist within the organization. Once an indication that the user has missed a telephone call from within the organization appears on the user&#39;s terminal, the user may choose from a list of names and extension or branch telephone numbers and return the call without having to search outside sources for the correct number. The return call may be accomplished by either an automatic callback feature or manually using the terminal. Additionally, the caller identification callback lists allow a user to select the people and associated extension or branch telephone numbers in advance without the prospective caller first calling the user.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates generally to an improved communications system, and in particular, to a method and system for improved caller identification. Still more particularly, the present invention relates to a method and system for developing caller identification callback lists for telephone calls originating from extension lines within organizational central office lines. 
     2. Description of Related Art 
     Caller-ID can be a helpful tool. When a call is received and caller-ID is activated on the recipient&#39;s telephone system, the telephone number from which the call is sent is displayed on the recipient&#39;s terminal. The originating telephone number is stored in a database, i.e. the originating central office equipment register. The originating telephone number supports a further database lookup, which associates a directory listing to the stored originating telephone number, assuming the originating number is listed. The name and number information is passed through the local and long distance networks, and appears on the recipient&#39;s caller-ID display. 
     Caller-ID is particularly useful when a call is placed and no one at the recipient number is available to take the call. When the recipient returns, the number is retrieved using the caller-ID feature. Therefore, the loss of the identity of the persons that may leave garbled or erased messages using an answering machine or voice mail or persons who do not leave messages at all, is avoided. 
     Although a worthwhile feature, caller-ID also has its shortcomings. One of the most prevalent is when a call originates from an organization which has a main telephone line but an array of extensions. When a call is placed from one of these extensions, the caller-ID feature on the recipient&#39;s terminal only records and displays the main switch number and the called party has no idea from which extension the called was placed or by whom. The recipient of the call must, in response, dial the main number recorded on the caller-ID display and attempt, using the organizational telephone directory, determine who made the call. The called party must either know with a fair amount of certainty who placed the call or try, by trial and error, to match names of people known by the called party within the organization with the appropriate extension. Either option can be at least frustrating and at most impractical and futile. 
     In view of the above, it would be advantageous to have a caller-ID system that provides for quick identification of extension or branch telephone numbers from a central office line within an organization. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method, system and computer readable instructions for use in a caller-ID callback list system which identifies an extension or branch telephone number of a caller along with the identity of the caller made from within an organization having at least one central office telephone number and more than one extension or branch telephone number. In particular, a subscriber at a recipient terminal may send a signal from the terminal to develop lists for enhanced identification of calls originating from a central office line within an organization. 
     According to one embodiment of the present invention, a subscriber maintains a list of caller-ID callback groups for extension or branch telephone numbers within an organization. The subscriber programs the terminal caller-ID callback list feature to establish a separate list for each central office telephone number. When a number originating from an identified central office telephone number calls the subscriber, the central office telephone number is displayed according to caller-ID protocol. With the central office telephone number identified, the subscriber may, through the use of subscriber generated lists, select the specific individual from within the list of individuals associated with the central office number to which the responding call should be directed. 
     Thus, with the present invention, a recipient can return a missed call with a fair amount of certainty even though the called originated from a central office telephone number consisting of multiple extension and/or branch telephone numbers. Other features and advantages of the present invention will be described in, or will become apparent to those of ordinary skill in the art in view of, the following detailed description of the preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is an exemplary block diagram of a typical communications system according to the present invention; 
     FIG. 2 is an exemplary block diagram of a typical Private Branch Exchange (PBX) switch according to the present invention; 
     FIG. 3 is an exemplary block diagram of a typical terminal according to the present invention; 
     FIG. 4 a  is an exemplary message flow diagram illustrating activation of a caller-ID callback list feature depicted in accordance with a preferred embodiment of the present invention; 
     FIG. 4 b  is an exemplary message flow diagram illustrating processing a call with a caller-ID callback list feature depicted in accordance with a preferred embodiment of the present invention; 
     FIG. 5 a ,  5   b , and  5   c  is an exemplary illustration of caller-ID callback list display options according to the present invention; 
     FIG. 6 is an exemplary illustration of caller-ID callback lists according to the present invention; 
     FIG. 7 is an example of entries used in a list or database for a caller-ID callback list depicted in accordance with a preferred embodiment of the present invention; 
     FIG. 8 is a flowchart of an exemplary operation used to provision a number for a caller-ID callback list feature depicted in accordance with a preferred embodiment of the present invention; 
     FIG. 9 is a flowchart outlining an exemplary operation for performing the caller-ID callback list display method according to the present invention; and 
     FIG. 10 is a flowchart of an exemplary operation for removing caller information from a caller-ID callback list depicted in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference now to the figures, FIG. 1 is an exemplary block diagram of a typical communications system according to the present invention. The present invention may be implemented in the various switches depicted in communications system  100  and also in the various telephones or terminals depicted in communications system  100 . Communications system  100  includes a public switched telephone network (PSTN)  116 , which includes switches  104  and  106 . Although depicted as separate from public switched telephone network (PSTN)  116  for illustration purposes, switches  104  and  106  and may actually be part of PSTN  116 . 
     Switch  104  and switch  106 , and private branch exchange (PBX)  102  are connected to each other via communications links  136 ,  138 , and  140 , which are physical links, such as, for example, coaxial cable, fiber optic cable, and the like. The communications links among switches  104  and  106  may be, for example, T 1  lines, E 1  lines, and the like. Each switch has a “link”, also called a “path”, within the switch for routing data through the switch. An “input link” is the input or source portion of the link associated with an input into the switch, and an “output link” is the output or destination portion of the link associated with an output from the switch. In addition, communications links  136 ,  138 , and  140  may be wireless. 
     Telephones  120 ,  122 ,  124 ,  126 ,  128  and  130  are connected to their respective switches as shown in FIG. 1, via communications links  150 ,  152 ,  154 ,  156 ,  162  and  164  which are also physical links that are typically copper twisted pairs but may consist of other types of connections, such as, for example, coaxial cable, fiber optic cable, and the like. In addition, communications links  150 - 164  may be wireless. For example, wireless connections may be part of PSTN  116 . 
     Data may be sent through a number of different paths using various communications links and switching within PSTN  116 . For example, an originating call within PBX  102  at telephone  120  may send information to a user in PSTN  116  through communications link  140  and then through communications link  138 . Alternatively, information may reach a user from telephone  120  within PBX  102  by sending data through a path starting with communications link  150 , through communications link  140 , through communications link  138 , through communications link  136 , and then through communications link  162 , to reach the user at telephone  128 . The various switches in PSTN  116  direct traffic between other switches to facilitate flow of information within this communications system. Data also may be transferred between other communications devices, such as computer  132  or facsimile machine  134 , within communications system  100  via communication links  158  and  160 , respectively. 
     Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 1 may vary. For example, other types of communication systems could be used, such as a cellular phones, personal communication services (PCS), cordless phones and the like may be used in addition or in place of the hardware depicted. FIG. 1 is intended as an example, and not as an architectural limitation for the present invention. 
     FIG. 2 is an exemplary block diagram of a typical Private Branch Exchange (PBX) switch according to the present invention. PBX switch  200  may be implemented as PBX  102  or switch  104  and  106  in accordance with the present invention. PBX switch  200  is an example of a switch in which the processes of the present invention may be implemented. In some cases, switch  200  may actually be implemented using a switch typically used in PSTN  116 . Switch  200  differs from a switch within PSTN  116  in FIG. 1 primarily in its capability to serve lines and process calls. A PBX typically serves fewer than a thousand stations and may process between 50,000 and 100,000 busy hour call attempts. It should be noted that the other PBX switches may include additional or different components from those illustrated in FIG.  2 . 
     In this example, switch  200  includes a computing module  202 , a database  204 , a central message controller  206 , and a network module  208 . In the depicted example, database  204  is resident in memory, but other types of databases are possible in alternate embodiments, including remotely located databases, and the like. 
     Central message controller  206  is connected to computing module  202  and to network module  208 , and controls the functions of network module  208  based on instructions received from computing module  202 . Computing module  202  handles all call processes of PBX switch  200  including, for example, tracking numbers, switch translation, caller-ID data, and configuration data. Computing module  202  accesses database  204  to access the data necessary to implement these processes. Network module  208  in essence forms a switch fabric for switch  200 . However, it should be noted that the switch fabric may include other components not shown. A switch fabric is the internal interconnect architecture used by a switching device, which redirects the data coming in on one of its ports out to another of its ports. Central message controller  206  controls switching of calls within network module  208 . 
     Ethernet module  210  is connected to network module  208  and provides a connection to a local area network. Trunk extended phone module  212  also is connected to network module  208  and provides a connection to a public switch telephone network, such as PSTN  116  in FIG.  1 . The trunk is an electronic path over which information is transmitted and, in particular, is a circuit between telephone exchanges for making connections between users. 
     Further, line extended peripheral module  214  is connected to network module  208 . Line extended peripheral module  214  provides an ability to control multiple line peripheral modules, such as line peripheral module  216 . Line peripheral module  216  provides a connection to terminal equipment, such as telephones  218  and  220 . Each line peripheral module may have multiple phones connected to it. 
     The caller-ID callback list feature of the present invention may be implemented as software executing on computing module  202 . In the depicted example, in response to a subscriber acknowledgement, caller-ID callback list software examines incoming caller line information for a call from an originating terminal and compares caller line identification with a list of directory numbers stored in database  204 . If the originating terminal directory number is found in database  204 , switch  200  displays a list, the list containing names of individuals which have been previously identified to be placed within a specific list. Otherwise, if the originating directory number is not stored in database  204 , switch  200  sends a message indicating the number is not in database  204 . 
     Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 2 may vary. For example, other types of telephone systems could be used, such as a cellular telephones, personal communication services (PCS), cordless telephones and the like may be used in addition or in place of the hardware depicted. FIG. 2 is intended as an example, and not as an architectural limitation for the present invention. 
     FIG. 3 is an exemplary block diagram of a typical terminal according to the present invention. Terminal  300  is an example of a terminal that may be connected to a switch, such as switches  104  and  106 , or a PBX, such as PBX  102  illustrated in FIG.  1 . Terminal  300  is also referred to as customer premises equipment (CPE). Terminal  300  is, for example, a telephone with a display although other communication equipment could also be used. For example, terminal  300  may be a computer, a Personal Digital Assistant (PDA), and the like. 
     Terminal  300  in this example is a telephone equipped to send, receive and display text messages, as well as functioning as a telephone, such as telephones  218 , and  220  illustrated in FIG.  2 . Terminal  300  includes a terminal driver  312 , which provides input and output to various parts of terminal  300 . In this example, terminal driver  312  is used to control handset  302 , keypad  304 , speaker  306 , and line keys  308 . Handset  302  allows a user to speak and hear a caller or called party. Key pad  304  allows a user to enter digits of a telephone number and to enter other information. Speaker  306  allows a user to listen to a caller or called party without the aid of handset  302 . Line keys  308  allow a user to select, from multiple phone lines, a line to use. 
     Terminal driver  312  also has a connection to a time division multiplexed (TDM) input/output (I/O) port  314 , which provides a connection to the telephone line. In addition, terminal driver  312  interfaces with application driver  316 . Application driver  316  performs all the processes of terminal  300 , including instructing display driver  318  to display information and/or messages to the subscriber on terminal display  320 . Furthermore, application driver  316  stores data received by terminal  300  in data storage  322 , from which this information may be retrieved by application driver  316  for later use. Application driver  316  is used to process various calls and data. In particular, application driver  316  may store information in data store  322 . Additionally, application driver  316  may send displays through display driver  318  to display information on terminal display  320 . In these examples, terminal display  320  is used to display caller-ID line identification to the user of terminal  300  to alert the user that a call was received and the user was not available to answer the call. 
     In these examples, terminal driver  312 , application driver  316 , and display driver  318  represent software or functional modules in terminal  300 . The other components depicted are illustrations of physical components within terminal  300  that may be controlled or accessed, by the use of either software of hardware, through these drivers. 
     Terminal  300  is an example of a terminal or phone on which the processes of the present invention may be implemented. Other terminals or telephones may be used as well, and may include more or fewer components than those shown in FIG.  3 . 
     Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 3 may vary. For example, terminal  300  may include a liquid crystal display (LCD), a voice prompt, voice recognition, and the like to allow a user to interface with terminal  300  and may be used in addition or in place of the hardware depicted. FIG. 3 is intended as an example, and not as an architectural limitation for the present invention. 
     FIG. 4 a  is an exemplary message flow diagram illustrating activation of a caller-ID callback list feature depicted in accordance with a preferred embodiment of the present invention. In a preferred embodiment of the present invention, the subscriber, in response to caller-ID information appearing on the subscriber&#39;s terminal  402 , may activate the caller-ID callback list feature and select the name and the corresponding extension or branch telephone number of the person who presumably placed the original call. In an alternate embodiment of the present invention, the subscriber at terminal  402  may activate the caller-ID callback list feature and enter the name and the corresponding extension or branch telephone number of a conceivable future caller before a call is received from that caller. 
     In this example, originating terminal  400  is originating a call to recipient terminal  402  from PBX  408  via switch  404 . Originating terminal  400  sends a request to switch  404  to set up a call to telephone  402  (step M 1 ). Switch  404  will use the digits contained in the call from originating terminal  400  to identify the call destination. Switch  404  signals recipient terminal  402  (step M 2 ). An answer is received by switch  404  from recipient terminal  402  (step M 3 ). The call is then connected between originating terminal  400  and recipient terminal  402  (step M 4 ). The caller line identification (CLID) of the originating caller is sent to terminal  402  (step M 5 ). The caller line identification may include the caller&#39;s name, phone number, or other identifying information. 
     Next, switch  404  may receive a feature activation code from terminal  402  (step M 6 ). This feature activation may be, for example, a subscriber lifting the handset on terminal  402  and entering a combination of keypad keystrokes, for example “99#”, which generates the appropriate dual tone multi-frequency (DTMF) signals recognized by switch  404 . Of course, other mechanisms may be used to activate the feature. For example, the subscriber may, if a telephone number is known before a call from a central office telephone number is placed, enter the name and the corresponding extension or branch telephone number to the appropriate list. In response, switch  404  sends a confirmation to recipient terminal  402  that the feature has been activated (step M 7 ). This confirmation may be, for example, a tone or voice message. 
     Organizational caller data is entered through terminal  402  via switch  404  to store on database  406  (step M 8 ). Switch  404  stores the subscriber defined caller-ID identification information for recipient terminal  402  in database  406 , which may be a local or remote database to switch  404  (step M 9 ). In response, database  406  sends a reply indicating that the information has been stored (step M 10 ). Switch  404  then sends a confirmation to terminal  402  that the information has been stored (step M 11 ). This confirmation may be, for example, a tone or voice message. 
     In the depicted examples, the switch  404  will respond to calls that are terminated, whether or not the call is answered by a subscriber at terminal  402 . In other words, a subscriber at recipient terminal  402  in step M 3  can answer the call and the feature may still be activated in accordance with a preferred embodiment of the present invention. 
     For example, a subscriber seeing an incoming call via caller-ID may recognize the number and know who is placing the call before picking up the receiver to answer the call. If so, the subscriber may choose to answer the call and activate the caller-ID callback list feature of the present invention after the conversation is complete. 
     FIG. 4 b  is an exemplary message flow diagram illustrating processing a call with a caller-ID callback list feature depicted in accordance with a preferred embodiment of the present invention. In this example, in response to a caller-ID message appearing on terminal  402  display, an acknowledgement is generated from terminal  402  to switch  404  (step M 12 ). Switch  404  requests a list of extension or telephone numbers from database  406  for the recipient, telephone  400  (step M 13 ). Database  406  determines whether the number queried in step M 13  exists in the database memory. An answer is given by database  406  to switch  404  (step M 14 ). If the number exists in the database, the answer will be a list from which the subscriber at terminal  402  may choose a terminal to call. Alternatively, if the number does not exist in the database  406 , the telephone call will be connected customarily, as if the present invention is not enabled on the user&#39;s telephone system. In a preferred embodiment, only telephone numbers that are identified by the user and are the parent of a caller-ID callback list are processed by the present invention. 
     Switch  404  then determines whether the directory number in the caller-ID identification information for originating terminal  400  is located in the list. Responsive to determining that the directory number for originating terminal  400  is present in the list, switch  404  returns a treatment to recipient terminal  402  (step M 15 ). The treatment may either be a list corresponding to the number stored in the caller-ID identification information if the number exists in database  406  or customary connection of the telephone call if the number does not exist in database  406 . If the extension or branch telephone number from within the central office telephone number exists in database  406 , a list corresponding to the central office telephone number displayed on the caller-ID terminal display is relayed to terminal  402 . 
     In the preferred embodiment, the list that appears, may be a subscriber defined list. From this list, the subscriber may choose from a list of names and corresponding extension or branch telephone numbers. The present invention allows the subscriber to identify a variety of groups which may place telephone calls to the user. The present invention allows the subscriber to easily choose a list in which to add the names of each subscriber defined group. Once a list is chosen, the subscriber adds names to the list and the corresponding extension or branch telephone number. Each list may include a list of names and corresponding extension or branch telephone numbers and may be displayed simultaneously, for example, in a scrollable display on terminal  402 . 
     The subscriber further narrows down the choices to decide from who the call was placed and may select a person and corresponding extension or branch telephone number from the displayed list. After choosing a caller and corresponding extension or branch telephone number, terminal  402  places the call to switch  404  (step M 16 ). In a preferred embodiment of the present invention, a automatic callback dial feature may be included on the terminal and once an identified caller is selected, terminal  402  may automatically dial the number selected. In an alternate embodiment, the subscriber may manually dial the number. Next, the signal is relayed from switch  404  to terminal  400  via PBX  408  (step M 17 ). Terminal  400  answers the call from switch  404  (step M 18 ). Switch  404  then connects to terminal  402  (step M 19 ) and the call is completed between terminal  402  and terminal  400  (step M 20 ). At some point in time, the call is disconnected (step M 21 ). At that point, in response to a disconnect signal from either the originating terminal or the recipient terminal, the connection is taken down and the originating and recipient terminals are idle. 
     FIG. 5 a ,  5   b , and  5   c  is an exemplary illustration of caller-ID callback list display options according to the present invention. In the following illustrations, the present invention displays options for caller-ID callback identification for a telephone call originating from a central office telephone number with the use of a Qualcomm™ Dual Analog Digital Mobile Telephone. However, the present invention is not limited to this particular telephone or the mobile telephone environment in general and may be implemented with other wired or wireless communication devices. For example, the present invention may be implemented by using a PCS telephone, a cordless telephone, a speaker telephone, and the like. Also, each option displayed on the communication device could be chosen by using, for example, a LCD display, a keypad, a voice prompt, voice recognition, and the like. 
     The particular example chosen to illustrate the features of this invention in FIG. 5 a ,  5   b ,  5   c , and  6  is the identification of persons and corresponding extension or branch telephone numbers in response to a missed telephone call originating from a central office line. However, the present invention may be applied at any time. Those of ordinary skill in the art will appreciate that the caller-ID callback list feature as described below can be utilized for callers before a call is placed to the subscriber terminal, in response to a call that is answered at the subscriber terminal, and the like. 
     In this example, the screen of the communication device may indicate to the subscriber the number of calls that have been received but remain unacknowledged in the “Missed Call” field  502 . In this example, the recipient terminal has missed one call. If there is a missed telephone call, the subscriber may select the “Ok” option  504  to further determine the identity of the originating caller and the corresponding extension or branch telephone number from which the missed call was placed. 
     If the subscriber selects the “Ok” option  504 , the next screen that may appear is the “Caller Identification” field  506 . This field may identify the caller, the time the call was placed, and the date on which the call was placed. In this example, the missed call was from “George Kraft” and was placed on Mar. 29, 2000 at 4:30 P.M. In addition, the “Caller Identification” field  506  may be configured to display system or subscriber defined information or a combination of both. In addition, a subscriber may choose caller attributes to suit the subscriber&#39;s specific needs. 
     The subscriber may now choose the “Phone List” option  508  or the “Features” option  510 . If “Phone List”  508  is chosen, the next screen that may appear is the “Phone List” screen  512 . The “Phone List” screen  512  may display several options, such as, for example, “Call List”  514 , “Phone Book”  516 , and “Find Name”  518 . If the subscriber selects “Call List”  514 , the next screen which may appear is the “Missed Call” screen  520  which may identify the location  522  and the telephone number  524  from which the missed call was placed. In this example, the missed telephone number was placed from a PBX labeled “Work” and the central office telephone number to the “Work” PBX is 512-555-1200. The “Missed Call” screen  520  may also display an “Options” selection  526  to further identify the extension or branch telephone number from which the missed call was placed. 
     If the subscriber selects “Options”  526 , the “Options” screen  528  may appear. The “Options” screen  528  may display a “Save” option  530 , a “Talk” option  532 , and a “Duration” option  534 . If the “Talk” option  532  is chosen, the next screen that may appear may display a list containing the name of a person previously identified by the subscriber who is associated with the organization from which the missed call originated. The displayed list may also include additional persons who have been defined by the subscriber also located at the central office telephone number from which the missed call originated. 
     In this example, since the number recorded on the caller-ID feature was placed from a central office telephone number, for example, “PBX Work”  536 , the subscriber&#39;s terminal display may display the corresponding list of persons associated with that particular central office telephone number. In this example, the “PBX Work” list  536  is displayed and may include names  538  and  540  which have been designated by the subscriber to be included in this specific list. Of course, other displays may also be used. For example, the displayed list may include names and corresponding telephone numbers, the name of the originating caller may be highlighted, the name of the originating caller may be flashing, and the like. 
     In this example, the “PBX Work” list  536  contains the names “George”  538  and “Olive”  540 . Since the subscriber knows the potential choices of individuals associated with the PBX number from the “Caller Identification” field  506 , the subscriber may now choose a name from the displayed list “PBX Work”  536 . If the subscriber chooses “George”  540 , the automatic callback feature of the communication device, if the device is so equipped, may place a call to a name on the list, for example, “George”  540 , using the extension or branch telephone number corresponding to “George”  540  at “Work”. Of course, other methods of returning calls may also be utilized. For example, the subscriber could manually key in a telephone number, the communication device may respond to a voice prompt, and the like. 
     Therefore, a subscriber to the present invention, after being notified of a missed telephone call via the subscriber&#39;s terminal display, may select, if the telephone call was placed from a extension or branch telephone number within a central office line, a name and associated extension or branch telephone number from a subscriber defined list. The list may correspond to the organization and central office telephone number which is displayed via the caller-ID feature on the subscriber&#39;s terminal. Then the extension or branch telephone number can be dialed to connect the subscriber to the presumed originator of the missed telephone call. 
     FIG. 6 is an exemplary illustration of a caller-ID callback list according to the present invention. The subscriber may create several callback lists, each list corresponding to a central office telephone number from which the subscriber may receive calls. In this example, the subscriber has defined an “All” telephone list  600  and a “Work” telephone list  620 . The “All” telephone list  600  may include identifiers of individuals known by the subscriber, such as, for example, names  602 ,  604 ,  606 ,  608 , and  610  which the subscriber has previously defined as possible callers and their corresponding telephone numbers  603 ,  605 ,  607 ,  609 , and  611 , respectively. In this example, “George”  602 , “Olive”  604 , “Jordan”  606  , “Meghan”  608 , and “Morgan”  610  have been identified by the subscriber with their corresponding telephone numbers at which they can be reach, for example, 555-1201  603 , 555-1202  605 , 555-1234  607 , 555-2345  609 , and 555-3456  611 , respectively. 
     In addition, the caller-ID callback “All” list  600  may also contain a entry which identifies an organization  612  and the corresponding central office telephone number  613 . In this example, “Work” is included in the “All” list and the corresponding main switch number is also displayed for “Work”, for example, 555-1200. 
     Furthermore, each entry on a caller-ID callback list may, if chosen, be an additional callback listing. If an entry on a displayed list is in itself an additional callback list, the entry may include a marker  614 . The marker may indicate to the subscriber of the caller-ID callback list feature that, when such a marker is present, an additional list  620  may be displayed on the display of the terminal including a further list of names  622  and  624  and corresponding telephone numbers  623  and  625 , respectively, for which a person can be reached. 
     In this example, since the entry “Work”  612  displays the central office telephone number, an asterisk (“*”) is included next to the central office telephone number for “Work”  612 . In addition, each name on a displayed list may be included on an additional list and may also be identified by an indicator, such as indicators  616  and  618 . In this example, since “George”  602  and “Olive”  604  are also included in the “Work” list  620 , the extension or branch telephone numbers corresponding to both “George”  602  and “Olive”  604  are shown with a plus (“+”) sign. 
     FIG. 7 is an example of entries used in a list or database for a caller-ID callback list depicted in accordance with a preferred embodiment of the present invention. In this example, entry  700  contains the originating terminal directory number in field  702 , a list identified by the subscriber in  704 , the name of a caller identified by the subscriber to be included in list  704  in field  706 , the directory number of the caller identified by the subscriber to be included in list  704  in field  708 , and an expiration date in field  710 . The originating terminal directory number in field  702  is used to sort or select extension or branch telephone numbers for a list. Alternatively, field  702  may be omitted and each entry may be associated with the subscriber activating the caller-ID callback list feature. In such a case, such an entry may be associated in a linked list for the subscriber. Although an expiration date is placed in field  710 , a time period also may be used. For example, some set number of days or months may be placed in field  710 . Alternatively, the caller-ID extension number may be permanent or at least until the caller-ID callback list feature is cancelled. 
     FIG. 8 is a flowchart of an exemplary operation used to provision a number for a caller-ID callback list feature depicted in accordance with a preferred embodiment of the present invention. In this example, the operation begins by receiving a feature activation code (step  800 ). A determination is then made as to whether or not the terminal has a subscription to the caller-ID callback list feature (step  802 ). If the terminal does not have a subscription to the caller-ID callback list feature (step  802 :NO), an error indication is returned via the terminal display panel (step  826 ) and the operation is terminated. Otherwise, if the terminal has a subscription to the caller-ID callback list feature (step  802 :YES), a determination is made as to whether or not the feature activation code is for the caller-ID callback list feature of the present invention (step  804 ). 
     If the entered feature activation code is not a code for the caller-ID callback list feature of the present invention (step  804 :NO), a determination is then made if the code is one for cancellation of the feature (step  820 ). If the code corresponds to cancellation of the caller-ID callback list feature (step  820 :YES), all organizational caller data is removed from the lists corresponding to this subscriber (step  822 ), a response is sent to the subscriber indicating the feature was successfully cancelled (step  818 ), and the operation is terminated. Alternatively, the switch could audibly present each directory number in a reject list and allow selective deletion. Otherwise, if the code received is not one for cancellation of the caller-ID callback list feature (step  820 :NO), the other feature corresponding to the feature code received is processed (step  824 ) and the operation is terminated. 
     Returning to step  804 , if the code received is one for the caller-ID callback list feature of the present invention (step  804 :YES), a determination is made as to whether or not the appropriate callback list has been defined (step  806 ). If an appropriate list has not been defined by the subscriber (step  806 :NO), a defined list is received (step  808 ) and the operation returns to step  806 . Otherwise, if the appropriate list has been defined (step  806 :YES), a name and corresponding extension or branch telephone number is added to the chosen list (step  810 ). 
     Then a determination is made as to whether or not the received feature activation code sets a time period (step  812 ). A time period may be set during which a call from an identified organizational extension or branch telephone number is desired by the user. This time period may be temporary or permanent. If a time period is not set by the feature activation code (step  812 :NO), the time period may be a default time period associated with the directory extension or branch telephone number in the list (step  814 ). Thereafter, a success response is sent to the subscriber via the terminal (step  818 ) with the operation terminating thereafter. Otherwise, if a time period has been set by the feature activation code (step  812 :YES), the time period set is associated with the identified directory extension or branch telephone number in the list (step  816 ). Thereafter, a success response is sent to the subscriber via the subscriber terminal (step  818 ) and the operation is terminated. A success response may be, for example, a tone or a voice message. 
     FIG. 9 is a flowchart outlining an exemplary operation for performing the caller-ID callback list display method according to the present invention. In this example, the operation begins by receiving a call for a subscriber terminal (step  900 ). A determination is made as to whether caller-ID identification information is available for the call (step  902 ). If caller-ID identification is not available (step  902 :NO), the operation is terminated. Otherwise, if caller-ID identification information is available (step  902 :YES), a “Phone List” screen may be displayed (step  904 ). Next, a “Missed Calls” list may be displayed (step  906 ). Following this, caller-ID identification information for the missed call may be displayed (step  908 ). Then an acknowledgement may be received in response to the displayed caller-ID information (step  910 ). 
     A determination is then made if the identified caller is included in a caller-ID callback list (step  912 ). If the caller is not identified in a list (step  912 :NO), a message is displayed indicating that the directory extension or branch telephone number is not identified and stored in the database (step  914 ), and then the operation is terminated. Otherwise, if the caller is included in a list (step  912 :YES), display options may be displayed to further identify the telephone extension or branch telephone number from which the missed call was placed (step  916 ). 
     Next, a caller-ID callback list corresponding to the caller-ID identification line information for the missed call may be displayed (step  918 ). The device may now use its automatic callback feature or the user may manually enter the number for the originator of the missed call (step  920 ). The call is connected (step  922 ) and the operation is terminated in response to a disconnect signal from either the originating terminal or the recipient terminal. 
     FIG. 10 is a flowchart of an exemplary operation for removing directory numbers from a caller-ID callback list depicted in accordance with a preferred embodiment of the present invention. In this example, the operation begins by retrieving the caller-ID callback list for a particular directory extension or branch telephone number (step  1000 ). An entry is selected from the list (step  1002 ). A determination is made as to whether the name and corresponding extension or branch telephone number have been manually removed by the subscriber (step  1004 ). If the number has been manually removed (step  1004 :YES), the name and corresponding directory number are removed from all lists and the database (step  1008 ). Otherwise, if the directory number has not been manually removed (step  1004 :NO), a determination is made as to whether a time period for the unprocessed entry has expired (step  1006 ). Typically, the entry will contain a period of time after which the directory number should no longer be needed. Also, it is possible that the entry is permanent and will not expire. 
     If the time period has expired (step  1006 :YES), the entry is removed from all lists and the database (step  1008 ). Otherwise, if the time period has not expired (step  1006 :NO), or after an entry is manually removed from the list and the database (step  1008 ), a determination is then made as to whether more unprocessed entries are present for processing (step  1010 ). If no more entries are on the list (step  1010 :NO), the operation terminates. Otherwise, if more entries are present (step  1010 :YES), a determination is made whether another entry has been selected (step  1012 ). If another entry has not been selected (step  1012 :NO), the operation terminates. Otherwise, if another entry has been selected (step  1012 :YES), the operation returns to step  1002  to select another entry for processing. 
     It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media such a floppy disc, a hard disk drive, a RAM, and CD-ROMs and transmission-type media such as digital and analog communications links. 
     The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.