Abstract:
In methods and apparatus for originating a voice call between first and second voice terminals, a voice call request is received at a data service node, the voice call request identifying the first voice terminal. A call origination request is transmitted from the data service node to a telecommunication switch, the call origination request identifying the first and second voice terminals. The telecommunications switch originates one call from the telecommunications switch to the second voice terminal and another call front the telecommunications switch to the first voice terminal. The telecommunications switch then connects the one call to the other call to connect the first voice terminal to the second voice terminal. The methods and apparatus are particularly useful in connection with advertising on the World Wide Web and in connection with international calling services.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/004,603, filed Sep. 29, 1995. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to methods and apparatus for originating voice calls, and more particularly to methods and apparatus for originating voice calls using a data terminal connected to a data service node. 
     BACKGROUND OF INVENTION 
     Today, many businesses are aggressively participating in the information highway phenomenon by advertising their goods and services on World Wide web home pages that are accessible to the general public via the Internet data network. The number of businesses advertising on the World Wide Web is exploding. 
     However, as businesses gain experience with advertising on the World Wide Web, they recognize that their home pages may not efficiently provide the information required by each individual customer or effectively sell their product or service to each individual customer. Many customers may browse their home pages on the World Wide Web, but may not take the time to investigate further to answer any remaining questions they may have, and the advertisers may miss business opportunities as a result. 
     To encourage customers to investigate further, and to provide the opportunity to sell directly to the customer, many advertisers provide a 1-800 number on their home pages and suggest that potential customers call for further information. 
     However, in order to route customer calls made to the 1-800 number to a specialist who can answer the particular customer&#39;s questions, the advertiser must use a human attendant or an interactive voice response system to route the calls based on the information desired by the customer. Customers who use the World Wide Web to find product and service information want to obtain that information quickly and with a minimum effort. Such customers consider the process of working through human attendants and interactive voice response systems to find the person who can answer their questions to be unacceptably time-consuming and tedious, especially when they are put on hold waiting for that person to become available. Consequently, many such customers wills not call 1-800 numbers to obtain further information, and the advertiser misses an opportunity to sell directly to the individual customer. 
     World Wide Web advertisers could overcome this problem by providing several distinct 1-800 numbers on their information pages and indicating clearly that. each 1-800 number will connect callers directly to someone who can deal with their specific questions. However, the requirement for several distinct 1-800 numbers would increase the advertiser&#39;s telecommunications costs considerably and would not assure the caller that someone will be available to answer their questions immediately when they call. 
     Today, telephone operating companies provide printed telephone directories including “yellow pages” which provide entries for businesses grouped according to the products or services provided by the businesses. Users of the “yellow pages” locate the product or service category of interest in the “yellow pages”, select a business based on its entry in the “yellow pages”, and dial the telephone number listed in the entry for that business. The user may make errors dialing the listed number. Moreover, even when the user dials correctly, the call may be unanswered, or may be connected to an interactive voice response system or a human attendant for further routing. As noted above, many users dislike working through interactive voice response systems and human attendants. 
     Today, the tariffs charged by a telephone operating company in a first country for placing a voice call to a second country may be significantly greater than the tariffs charged by a telephone operating company in the second country for placing a voice call from the second country to the first country. For example, the voice tariffs charged by a Japanese telephone operating company for placing a call from a first directory number in Japan to a second directory number in the US are considerably higher than the rates charged by a US telephone operating company for placing a call from the second directory number in the US to the first directory number in Japan. US service providers capitalize on this discrepancy by offering services by which a Japanese caller can call a US service provider and request a connection between the first directory number in Japan and the second directory number in the US. The US service provider then places a first call to the second directory number in the US, a second call to first directory number in Japan and connects the first and second calls to provide the desired connection. Because the connection is made from the US to Japan, the Japanese caller can be charged at a rate based on the lower tariffs charged by a US telephone operating company. However, the Japanese caller must also pay the cost of the short call from Japan to the US service provider required to set up the desired call. 
     SUMMARY OF INVENTION 
     An object of this invention is to provide methods and apparatus for originating voice calls between voice terminals using a data terminal and a data service node without requiring interaction with human attendants or interactive voice response systems to complete the call. 
     One aspect of the invention provides a method for originating a voice call between a first voice terminal and a second voice terminal. According to the method, a voice call request is sent from a data terminal to a data service node, the voice call request identifying the first voice terminal. A call origination request is transmitted from the data service node to a telecommunications switch, the call origination request identifying the first and second voice terminals. Two calls are originated at the telecommunications switch one call is from the telecommunications switch to the second voice terminal, and another call is from the telecommunications switch to the first voice terminal. The one call is connected to the other call at the telecommunications switch to connect the first voice terminal to the second voice terminal. 
     The data service node may display a command menu (for example a plurality of command icons) at the data terminal. In this case, the command menu comprises a voice call request command (for example a voice call request icon), and the data service node interprets selection of the voice call request command as a voice call request. The voice call request icon may comprise a data entry field and may indicate that the first voice terminal identifier is to be entered into the data entry field before selecting the voice call request icon. Alternatively, the data terminal may be operable in response to selection of the voice call request icon to read the first voice terminal identifier from a mail profile of the data terminal and to transmit the first voice terminal identifier to the data service node via the data network. The alternative approach requires additional software at the data terminal, but avoids the need for the operator of the data terminal to type the first voice terminal identifier each time a voice call is requested. 
     Advantageously, the command menu may comprise plural distinct voice call request commands, and the data service node may respond to distinct voice call request commands by transmitting to the telecommunications switch call origination requests comprising distinct respective second voice terminal identifiers. In this case, different voice call request commands may be executed to obtain different types of information and, in each case the request or of the voice call will be called by a particular agent who is familiar with the desired information. The voice call request commands displayed may explicitly state the type of information available if the voice call request commands are selected, or the type of information to be provided (and consequently the particular second voice terminal identifier to be included in the voice call origination request) may be inferred by the data service node from the context in which each distinct voice call command request appears in the data displayed at the data terminal. 
     The telecommunications switch may be programmed to originate the second call only when the first call has been accepted at the second voice terminal. In this case, the data service node may maintain a queue of call origination requests at the data service node when the second voice terminal is busy and may transmit from the data service node to the telecommunications switch the next call origination request in the queue each time the second voice terminal becomes idle. 
     In one application of the above method, the data service node may provide advertising services on the World Wide Web, and the data terminal may be operated by a potential customer accessing the advertising services via the Internet. The first voice terminal may be a telephone of the potential customer, and the second voice terminal may be a telephone of a business advertising by means of the advertising services. The potential customer may request a voice connection with the business by executing a command on the data terminal. The advertising services may be telephone directories or “yellow pages” accessed by the potential customer on the World Wide Web. 
     The call origination method described above minimizes the potential customer&#39;s inconvenience by automatically having an agent of the advertiser call the customer when that agent is available. Because the voice call is placed from the advertiser&#39;s agent to the potential customer, the potential customer is assessed no telecommunications charges. Consequently, the advertiser does not need to buy 1-800 service to avoid telecommunications charges to its potential customers. Because the advertiser does not require 1-800 service, the advertiser may provide several distinct call request commands without incurring a telecommunications cost penalty. Each distinct call request command may be made specific to a particular product line or type of information, so that the potential customer is assured of being connected to an agent that can provide the information or service required. It is anticipated that the increased convenience to the potential customer provided by this call origination method will enable World Wide Web advertisers to sell directly to at least some of those potential customers who are unwilling to call the 1-800 number presently provided on World Wide Web advertising pages, enabling the advertisers to sell directly to more potential customers. 
     Some advertisers may operate multiple geographically spaced data service nodes to serve potential customers over a large geographic area. Such advertisers may want to refer call origination requests to the agents who are located closest to the potential customer. To meet this requirement, the method described above may be extended to accommodate multiple data service nodes such that each data service node can forward voice call requests to other data service nodes. The data service node which receives the voice call request may select another data service node to which the voice call request may be forwarded based on the first voice terminal identifier. 
     In another application of the method described above, the data service node may be operated by a business offering international calling services, and the data terminal may be operated by an international caller who wishes to avoid high tariffs for placing voice calls from his home country to a foreign country. The international caller may request origination of a call between his telephone and a telephone in a foreign country using his data terminal. The data service node may cause a telecommunications switch in the foreign country to place calls to the voice terminal of the called party in the foreign country and to the voice terminal of the international caller to complete a voice connection by making only calls originated in the foreign country. No call from the home country to the foreign country is needed to set up the call, and no interaction with interactive voice response or human attendants is needed to set up the call. 
     Another aspect of the invention provides a data service node for connection to a data network to provide a data service. The data service node comprises means for receiving a voice call request and a first voice terminal identifier from a data terminal connected to the data service node via the data network, the first voice terminal identifier identifying a first voice terminal associated with the data terminal. The data service node further comprises means for transmitting to a telecommunications switch a call origination request comprising the first voice terminal identifier and a second voice terminal identifier, the second voice terminal identifier identifying a second voice terminal associated with the data service node. 
     Another aspect of the invention provides a data service system, comprising a data service node for connection to a data network to provide a data service and a telecommunications switch connected to the data service node. The data service node comprises means for receiving a voice call request and a first voice terminal identifier from a data terminal connected to the data network, the first voice terminal identifier identifying a first voice terminal associated with the data terminal, and means for transmitting to the telecommunications switch a call origination request comprising the first voice terminal identifier and a second voice terminal identifier, the second voice terminal identifier identifying a second voice terminal associated with the data service node. The telecommunications switch comprises means responsive to the call origination request to originate one call from the telecommunications switch to the second voice terminal and another call from the telecommunications switch to the first voice terminal. The telecommunications switch further comprises means for connecting the one call to the other call to connect the first voice terminal to the second voice terminal. 
     The data service system may comprise a plurality of data service nodes and a plurality of telecommunications switches, each data service node being connected to a respective telecommunications switch and being operable to forward voice call requests to others of the data service nodes. The data service nodes may select other data service nodes for the forwarding of voice call requests based on the first voice terminal identifiers. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     Embodiments of the invention are described below by way of example only. Reference is made to accompanying drawings in which: 
     FIG. 1 is a block schematic diagram showing interconnected telecommunications networks incorporating one embodiment of the invention; 
     FIG. 2 is an information flow diagram summarizing information flows in the interconnected networks of FIG. 1 as required to generate and execute a voice call request; and 
     FIG. 3 is a flow chart illustrating steps in a first task performed by a data service node of the telecommunications networks of FIG. 1 to process a voice call request; 
     FIG. 4 is a flow chart illustrating steps in a second task performed by a data service node of the telecommunications networks of FIG. 1 to process a voice call request; 
     FIG. 5 is a block schematic diagram showing interconnected telecommunications networks incorporating another embodiment of the invention; 
     FIG. 6 is a block schematic diagram showing interconnected telecommunications networks incorporating another embodiment of the invention; 
     FIG. 7 is an information flow diagram summarizing information flows in the interconnected networks of FIG. 6 as required to generate and execute a voice call request; 
     FIG. 8 is a block schematic diagram showing interconnected telecommunications networks incorporating another embodiment of the invention; and 
     FIG. 9 is a block schematic diagram showing interconnected telecommunications networks incorporating another embodiment of the invention. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 is a block schematic diagram showing interconnected telecommunications networks incorporating an embodiment of the invention. 
     A data terminal in the form of a first workstation  100  comprises a processor  101 , a memory  102  storing instructions for execution by the processor  101 , a keyboard  103  for providing manual inputs to the processor  101  and a display  104  for displaying data to an operator of the workstation  100 . The workstation  100  further comprises. a modem  106  for formatting data for transmission over the Public Switched Telephone Network (PSTN)  200 . 
     A voice terminal in the form of a telephone  110  is located near the workstation  100  and is intended for the use of the operator of the workstation  100 . The telephone  110  is also connected to the PSTN  200 . 
     For example, the workstation  100  and the telephone  110  may be located in the operator&#39;s home. The operator may use the workstation  100  to obtain access to a data network in the form of the Internet  300  via the PSTN  200 . A modem pool  302  links the PSTN  200  to the Internet  300  for this purpose. The memory  102  of the workstation  100  contains browser software (for example Netscape™), which the operator may use to “navigate” among various data services provided via the Internet  300 . 
     Another data terminal in the form of a second workstation  400  comprises a processor  401 , a memory  402  storing instructions for execution by the processor  401 , a keyboard  403  for providing manual inputs to the processor  401  and a display  404  for displaying data to an operator of the workstation  400 . The workstation  400  further comprises a LAN interface  406  for formatting data for transmission over a Local Area Network  410 . 
     A voice terminal in the form of a telephone  420  is located near the workstation  400  and is intended for the use of the operator of the workstation  400 . The telephone  420  is connected to the PSTN  200  via a Private Branch Exchange (PBX)  430 . 
     For example, the workstation  400 , the LAN  410 , the telephone  420  and the PBX  430  may be located at the operator&#39;s place of business. The operator may use the workstation  400  to obtain access to a data network in the form of the Internet  300  via the LAN  410 . An Internet gateway  304  links the LAN  410  to the Internet  300  for this purpose. The memory  402  of the workstation  400  contains “browser software” (for example Netscape™), which the operator may use to “navigate” among various data services provided via the Internet  300 . 
     A data service node  500  is connected to the Internet  300  to provide data services. The data service node  500  comprises an Internet interface  502 , a processor  504 , and a memory  506 . The memory  506  stores instructions to be executed by the processor  504  and data to be used by the processor  504  in executing those instructions. In particular, the memory  506  contains HyperText Transfer Protocol (HTTP) server software which enables the data service node  500  to forward World Wide web home pages to the workstations  100 ,  400  over the Internet  300  upon receipt of messages from the workstations requesting those home pages. 
     As is conventional in the operation of the World Wide Web, the data service node forwards HTMT, instructions to the workstation  100  together with the data required for display of the home pages. The HTML instructions are stored in the memory  102  and are executed by the workstation  100  when command icons displayed on the home pages are selected by the operator of the workstation  100  to send a message to the data service node  500 , and the data service node  500  responds to the message to execute, the command corresponding to the icon. Some of the command icons may include data entry fields and textual instructions for filling of the data entry fields by the operator of the workstation  100 . When such command icons are selected at the workstation  100 , downloaded HTML instructions are executed at the workstation  100  to send a message incorporating the content of the data entry field to the data service node  500 . 
     HTTP instructions stored in the memory  506  of the data service node  500  enable the data service node  500  to receive messages from the workstation  100  and to execute commands corresponding to those messages. The memory  506  may store additional software applications in languages other than HTTP. These applications may be executed in response to receipt of particular messages by the HTTP software. 
     According to an embodiment of the invention, the memory  506  of the data service node  500  contains HTTP instructions which enable the processor  504  to display voice call request icons on home pages forwarded to the workstation  100  from the data service node  500 . The voice call request icons incorporate a data entry field and text instructing the operator of the workstation  100  displaying the home pages containing the icons to enter in the data entry field the directory number of the voice terminal (for example telephone  110 ) on which the operator wishes to receive a voice call, and then to select the icon in order to request a voice call. The memory  506  contains further HTTP instructions which enable the data service node  500  to receive messages corresponding to voice call request commands from the workstation  100  and call processing applications (described in more detail below) which are executed by the data service node  500  on receipt of messages corresponding to voice call request commands. 
     According to the embodiment of the invention the data service node  500  further comprises a PBX interface  508  which connects the processor  504  to a PBX  530 . The PBX interface  508  enables the processor  504  to communicate with the PBX  510  using standard Advanced Intelligent Network (AIN) protocols to control call processing by the PBX  510  and to obtain call status information from the PBX  510 . The PBX  510  connects second voice terminals in the form of telephones  520 ,  530  to the PSTN  200 , and includes Automatic Call Distribution (ACD) software for monitoring the status of the telephones  520 ,  530  and for distributing incoming calls to the telephones  520 ,  530 . 
     Another data service node  600  is also connected to the Internet  300  to provide data services. Like the data service node  500 , the data service node  600  comprises an Internet interface  602 , a processor  604 , a memory  606 , and a PBX interface  608  connected to a PBX  610  serving telephones  620 ,  630 . Each element of the data service node  600  performs the same functions as the corresponding element of the data service node  500 . 
     In one application of the interconnected networks described above, the operator of workstation  100  connects the workstation  100  to the Internet  300  via the PSTN  200  using conventional Internet access procedures. Using the browser software stored in the workstation  100 , the operator uses conventional browsing procedures to locate World Wide Web home pages and to display those home pages on the workstation  100 . 
     In this application example, the operator locates and displays a home page provided by data service node  500 . The home page content advertises goods or services marketed by a particular business. The displayed home page includes voice call request icons as described above, and HTML instructions corresponding to the voice call request icons are downloaded from the data service node  500  to the workstation  100  together with the data needed to display. the home page. 
     The operator of the workstation  100  wants more information than is displayed on the home page and decides to execute the voice call request command to obtain the desired information. The operator enters the directory number of the telephone  110  in the data entry field as instructed by the text of the voice call request icon and selects the icon. The workstation  100  executes HTML instructions corresponding to the voice call request icon to send to the data service node  500  a call request message incorporating the entered directory number. 
     The data service node  500 .receives and interprets the message using HTTP software which triggers application software to select a second voice terminal identifier in the form of an extension number for one of the telephones  520 ,  530  connected to the PBX. The directory number and the selected extension number are forwarded to the call processing application which formulates a call origination request containing the directory number and the extension number, and sends the call origination request to the PBX  510  via the PBX interface  508 . 
     The PBX  510  processes the call origination request to originate a first voice call from the PBX  510  to the telephone  520  associated with the data service node  500 . When the first voice call is answered at the telephone  520 , the PBX  510  originates a second voice call from the PBX  510  to the telephone  110  associated with the workstation  100 . When the second voice call is answered at the telephone  110 , the PBX  510  connects the two calls to connect the telephone  110  to the telephone  520 . 
     The call is connected via the PSTN, so that an agent of the advertising business using a telephone  520  at the selected extension number can talk directly to the operator of the workstation  100  using the telephone  110  at the specified directory number. Because the call is originated by the advertising business, the advertising business is billed by the PSTN provider for any telecommunications charges resulting from the voice call. 
     The information flows required to process the voice call request are summarized in FIG.  2 . 
     In the same way, the operator of workstation  400  (see FIG. 1) can connect to the Internet  300  in a conventional manner, locate and display the home page provided by the data service node  500 , and select a voice call request icon to request a return voice call, and the data service node  500  and the PBX  510  will process the voice call request to connect the telephone  520  associated with the data service node to the telephone  420  associated with the workstation  400 . 
     The HTTP instructions stored in the data service node  500  may be such as to provide the home pages with multiple voice call request icons, each corresponding to information of a different type. In this case, the application software instructions which are executed to formulate the call origination request may select from among multiple extension numbers depending on which of the voice call request icons was selected by the workstation operator. If the operator of the workstation  100  selects a voice call request icon which appears in the context of information about a first product, for example, the data service node  500  may formulate a call origination request containing the extension of the telephone  520  which is assigned to an agent who has information concerning the first product. If the operator of the workstation  100  selects a voice call request icon which appears in the context of information about a second product, the data service node  500  may formulate a call origination request containing the extension of another telephone  530  which is assigned to another agent who has information concerning the second product. 
     The call processing application of the data service node  500  may sense the busytidle status of the telephones  520 ,  530  connected to the PBX  510  via the PBX interface  508  using the standard AIN protocol of the PBX interface  508 . In this case, the call processing application of the data service node may maintain a queue of call origination requests for each of the telephones  520 ,  530  when those telephones are busy. The data service node  500  transmits the next call origination request in the queue to the PBX  510  each time the busy telephone becomes idle. The data service node  500  may display the position of the call origination request in the queue on the workstation from which the call origination request was received so that the operator knows when to expect a voice call in response to the request. 
     When the telephones  520 ,  530  are all busy, the data service node  500  may download a command menu to the workstation  100 , inviting the operator of the workstation  100  to communicate via alternative means, e.g. electronic mail, voice mail or short message service. When the appropriate commands are selected from the menu at the workstation  100 , downloaded HTML instructions can be executed to connect the workstation to the requested service to enable the operator of the workstation to communicate by the selected means. 
     Large businesses may provide advertising home pages from geographically separated data service nodes  500 ,  600 . In this case, the operator of the workstation  100  may access the home pages provided by a relatively remote data service node  500  and issue a voice call request. The advertising business may prefer that the requested voice call be made by an agent who is located closer to the operator of the workstation. The HTTP software which handles incoming messages corresponding to voice call requests may screen such messages based on the directory number contained therein, and forward some messages to another data service node  600  which is located closer to the operator of the workstation  100 . The data service node  600  to which the voice call is forwarded then processes the voice call request to originate a call from a telephone  620  to the telephone  310  at the directory number specified by the operator of the workstation. The data service node to which voice call requests are forwarded could also be selected on the basis of time of day to provide voice call service over extended hours when local agents may not be on duty, or on the basis of monitored traffic loads to provide faster service to workstation operators requesting voice calls. 
     The voice call request icons placed at different locations on the pages of information displayed at the workstation  100  can correspond to different sets of HTML instructions providing different messages to the data service node  500  causing the data service node  500  to route resulting calls to different extensions  520  of the PBX  510 . Consequently, the extension  520  can be selected based on the context of the voice call request command to ensure that the agent responding to the voice call request is familiar with the information likely to be requested. 
     Alternatively, the different sets of HTML instructions corresponding to each voice call request icon can provide messages to the data service node  500  which cause the data service node  500  to route the calls to the same extension  520 , but with information about the context of the voice call request. The information could either be displayed at the agent&#39;s workstation or audibly announced to the agent when the call is accepted at the extension  520 . 
     The voice call request icon displayed at the workstation  100  could include data fields which could be filled by the operator of the workstation. The HTML instructions executed by the workstation  100  could be such as to include the content of these fields in the message sent to the data service node  500  upon selection of the voice call request icon. The data service node could then relay the content of these fields to the agent&#39;s workstation for display or to the agent&#39;s extension via text to speech conversion and audible announcement. For example, such data fields could include details of the information the operator of the workstation  100  wishes to obtain from the agent. 
     FIGS. 3 and 4 are flow charts illustrating how the processes performed by the data service node  500  as described above may be implemented as two tasks. The first task, illustrated in FIG. 3, receives voice call requests and voice terminal directory numbers, processes these to formulate origination requests, and inserts the origination requests into appropriate queues. The second task, illustrated in FIG. 4, transfers the origination requests from the queues to the PBX to complete the requested voice calls. 
     The embodiments described above may be modified without departing from the principles of the invention. For example, the directory number of the telephone  110  (see FIG. 1) may be stored in the mail profile of the browser software at the workstation  100 , and the HTML instructions downloaded from the data service node  500  to the workstation  100  for execution when the voice call request icon is selected may request the directory number from the mail profile without requiring that the operator type the directory number. In this case the downloaded HTML instructions may display the directory number obtained from the mail profile at the workstation  100  and may request that the operator of the workstation  100  confirm or modify the directory number as appropriate before transmitting the voice call request message to the data service node  500  in a further refinement, the agents of the advertising business may be provided with data terminals connected to the processor  504  of the data service node  500 . The HTTP software of the data service node  500  may download the same information to the data terminal of the agent as is downloaded to the workstation  100  so that the agent and the operator of the workstation view the same displayed information. The data terminals of the agents may be enabled to download information from the data service node  500  to the workstation  100  so that the agent can control the information displayed at the operator&#39;s workstation  100 . This enables the operator requesting the voice call and the agent of the advertising business to converse with both voice and images simultaneously. 
     The call processing application of the data service node  500  may be programmed to call from the PBX  510  to the telephone  110  at the specified directory number, to provide a voice announcement indicating that the agent will join the call shortly when the call is successfully answered at the telephone  110 , and to connect the call through to the agent&#39;s extension  520  only when the call has been successfully answered at the telephone  110 . This maximizes the efficiency of the agents, though this feature should be used judiciously to avoid alienating the operator of the workstation  100 . 
     Alternatively, the PBX  510  could place the call to the agent&#39;s extension  520  first, and place the call to the telephone  110  only when the agent has accepted the call. This maximizes the convenience of the potential customer, but reduces the efficiency of the agent. 
     The PBX interface  508  could communicate with the PBX  510  using protocols other than AIN. For example, other standardized protocols such as the Computer Telephony Interface (CTI) or the Small Computer Application Interface (SCAI) could be used, or proprietary protocols, such as the Meridian Links™ protocol to Northern Telecom™, could be used. The data service node  500  and the PBX could be integrated on a single computer platform, or the data service node  500  could communicate with telecommunications switches of the PSTN  200  using standard AIN protocols. Voice calls could be routed from the PBX  510  via the PSTN  200  to voice terminals at remote locations, for example to agents, homes if agents are “telecommuting”, or to other locations of the advertiser&#39;s business. 
     These and other modifications are within the scope of the invention as defined by the claims below. 
     FIG. 5 is a block schematic diagram of interconnected telecommunications networks which implement. another embodiment of the invention. This architecture may be used, for example, to implement an Internet “Yellow Pages” service. 
     The interconnected networks of FIG. 5 are essentially as illustrated in FIG. 1, except that the data service node  500  is connected to a telecommunications switch  540  which may not be a PBX. The telecommunications switch  540  is connected to the PSTN  200  and may be integrated with the data service node  500 . 
     In one application of the interconnected networks of FIG. 5, the operator of workstation  100  locates and displays World Wide Web “Yellow Pages” provided by the data service node  500 . The operator of the workstation  100  locates the listing which interests him and executes the voice call request command associated with that listing. The workstation  100  executes HTML instructions corresponding to the voice call command to send the data service node  500  a call request message incorporating the directory number of his telephone  110 . 
     The HTTP software of the data service node  500  receives and interprets the message and triggers application software running on the data service node  500  to select a directory number associated with the listing corresponding to the voice call command associated with the listing selected by the operator of the workstation  100 . The directory number is forwarded to call processing software which formulates and sends a call origination message containing the directory number of the telephone  110  and the directory number associated with the selected listing to the telecommunications switch  540 . 
     The telecommunications switch  540  processes the call origination request to originate a voice call from the telecommunications switch  540  via the PSTN  200  to a telephone  120  corresponding to the directory number associated with the selected listing. The telecommunications switch  540  also originates a voice call from the telecommunications switch  540  to the telephone  110  of the person requesting the call. The telecommunications switch  540  connects the two calls to connect the telephone  110  to the telephone  120  via the PSTN  200  and the switch  540 . Because the person requesting the call selects the listing on a displayed screen of information, dialling errors are avoided. Moreover, because the telecommunications switch  540  is connected to the telephones  120  of businesses having listings in the “Yellow Pages” via the PSTN  200 , the data service node  500  can provide call closure services to businesses which are geographically dispersed. 
     In another application of the network architecture of FIG. 5, the data service node provides an international calling service. The operator of workstation  100 , located for example in Japan, accesses and displays a World Wide Web page of a US service provider implemented on the data service node  500 . The operator of the workstation  100  executes a voice call request command which specifies the directory number of a telephone  120  in the US to which he wishes to place a call. The workstation  100  executes HTML instructions corresponding to the voice call command to send the data service node  500  a call request message incorporating the directory number of his telephone  110  and the directory number of the telephone  120  he wishes to call. The call request message also includes any authorization codes needed to ensure that the service is restricted to valid subscribers, and any billing codes (e.g. calling card numbers) needed to bill the cost of the call back to the caller. 
     The data service node  500  receives the message, and formulates and sends a call origination message containing the directory number of the telephone  110  and the directory number of the telephone  120  to the telecommunications switch  540 . 
     The telecommunications switch  540  processes the call origination request to originate a voice call from the telecommunications switch  540  via the PSTN  200  to the telephone  120 . The telecommunications switch  540  also  35  originates a voice call from the telecommunications switch  540  to the telephone  110 . The telecommunications switch  540  connects the two calls to connect the telephone  110  to the telephone  120  via the PSTN  200  and the switch  540 . Because the call is connected from the US to Japan, the person requesting the call can be billed at rates based on the relatively lower tariffs for placing international calls from the US. Moreover, the person requesting the call is not required to place a voice call from Japan in order to set up the desired call from the US. 
     The architecture shown in FIG. 5 requires that each data service node  500  have associated telecommunications switching functionality  540 . Because this functionality is relatively expensive, this requirement may inhibit smaller service providers from entering the marketplace. FIG. 6 is a block schematic diagram illustrating an alternative architecture which separates the telecommunications switching functionality from the functionality which provides data to workstation operators via the Internet  300  so that the telecommunications switching functionality can be provided to data service providers as needed by another service provider. According to FIG. 6, the data service node  500  is connected to another data service node  700  via the Internet, and the other data service node  700  is connected to a telecommunications switch  710  which is connected to the PSTN  200 . 
     In an application of the architecture of FIG. 6, the operator of workstation  100  locates and displays World Wide Web pages provided by the data service node  500 . The operator of the workstation  100  executes a voice call request command on the page of displayed information to request a voice connection. The workstation  100  executes HTML instructions corresponding to the voice call command to send the data service node  500  a call request message incorporating the directory number of his telephone  110 . 
     The data service node  500  receives the message and selects a directory number associated with the particular voice call request command executed by the operator of the workstation  100  (unless the voice call request command already includes both directory numbers). The data service node  500  formulates and sends a call origination message containing both directory numbers and a billing code to the other data service node  700  via the Internet  300 . 
     The other data service node  700  verifies that the billing code is valid and forwards the call origination request to the telecommunications switch  710 . The telecommunications switch  710  processes the call origination request to originate a voice call from the telecommunications switch  710  via the PSTN  200  to the telephone  120 . The telecommunications switch  710  also originates a voice call from the telecommunications switch  710  to the telephone  110 . The telecommunications switch  710  connects the two calls to connect the telephone  110  to the telephone  120  via the PSTN  200  and the switch  710 . Once the calls complete, the telecommunications switch  710  sends a call detail record back to the service node  700 , and the service node  700  sends billing information to the data service node  500  so that the cost of the call can be billed, either to the operator of the workstation  100  or to the business for which the service is provided on the service node  500 , depending on the nature of the service. (For example, international callback services and the like would be billed to the caller, while yellow pages services would be billed to the advertiser.) 
     The information flows discussed above are summarized in FIG.  7 . In FIG. 7, the voice call Request  2  may contain the voice terminal identifier of the called telephone  120  in addition to the voice terminal identifier of the calling telephone  110  for services such as international callback. For such services, the Voice Call Request  2  could also contain authentication and billing codes used to screen use of the service and to bill the user of the service. The Voice call Request  2  could also contain text or voice messages to be forwarded upon connection to the telephone  120 . 
     The Call Origination Request  3  will contain the voice terminal identifiers for both the calling telephone  110  and the called telephone  120 , as well as any information needed to identify the data service node  500  or workstation  100  for authentication and billing purposes. The Call Origination Request  3  could also include text or voice messages to be forwarded upon connection to either of the telephones  110 ,  120 , or the addresses of standard text or voice messages which are stored at the service node  700 , the telecommunications switch  710 , or peripherals connected to the switch  710 . The Call Origination Request  3  could further include sets of executable instructions to be executed by the service node  700  in processing the Call Origination Request  3 . 
     The forwarded Call Origination Request  4  will contain the voice terminal identifiers for both the calling telephone  110  and the called telephone  120  and a call identifier. The forwarded Call Origination Request  4  may also include text messages to be converted to speech at the telecommunications switch  710  (or one its peripherals) and played upon connection of the telephones  110 ,  120 , voice messages to be played upon connection of the telephones  110 ,  120 , or the addresses of standard voice messages which are stored at the telecommunications switch  710  or one of its peripherals. 
     The Call Processing Messages  5  are conventional call processing messages as are required to establish the connections from the switch  710  to the telephones  110 ,  120  and to link the connections at the switch  710 . 
     The Call Detail Record  6  includes all information needed to bill the call, including the call identifier, identifiers of the telephones  110 ;  120 , call duration and time, etc. The service node  700  (or a billing peripheral) processes the Call Detail Record  6  to formulate the Billing Information  7 , which is forwarded to the data service node  500 . 
     Further information flows may be added to those shown in FIG.  7 . For example, if the data service node  500  will not provide the requested service, an appropriate message may be sent back to the. workstation  100 . Similarly, if the service node  700  will not provide the requested service, appropriate messages may be sent from the service node  700  to the data service node  500  and from the data service node  500  to the workstation  100 . The service node  700  may also send an appropriate message to the data service node  500  when the call is being placed, and the data service node  500  may then send an appropriate message to the workstation  100 . The data service node  500  may forward some of the billing data to the workstation  100  for some services. 
     In the architecture of FIG. 6, the other data service node  700  and the telecommunications switch  710  can provide call completion services to several data service nodes  500  which provide data services including voice call request icons. Each data service node  500  may provide a different data service. 
     Call completion services could also be provided by Inter-Exchange Carriers (IECs) using service node functionality and telecommunications switching functionality present in the PSTN  200 . FIG. 8 is a block schematic diagram showing an architecture in which a service node  210  of the PSTN  200  is connected to plural telecommunications switches  220  of the PSTN  200 . 
     In an application of the architecture of FIG. 8, the operator of workstation  100  locates and displays World Wide Web pages provided by the data service node  500 . The operator of the workstation  100  executes a voice call request command on the page of displayed information to request a voice connection. The workstation  100  executes HTML instructions corresponding to the voice call command to send the data service node  500  a call request message incorporating the directory number of his telephone  110 . 
     The data service node  500  receives the message and selects a directory number associated with the particular voice call request command executed by the operator of the workstation  100  (unless the voice call request command already includes both directory numbers). The data service node  500  formulates and sends a call origination message containing both directory numbers and a billing code to the PSTN service node  210  via the Internet  300 . 
     The PSTN service node  210  verifies that the billing code is valid and forwards the call origination request to one of the telecommunications switches  220 , the switch being selected according to the directory numbers of the telephones  110 ,  120  using routing tables at the service node  210  The selected telecommunications switch  220  processes the call origination request to originate a voice call from the selected telecommunications switch  220  via the PSTN  200  to the telephone  120 . The selected telecommunications switch  220  also originates a voice call from the selected telecommunications switch  220  to the telephone  110 . The selected telecommunications switch  220  connects the two calls to connect the telephone  110  to the telephone  120  via the PSTN  200  and the selected switch  220 . Once the call is complete, the data service node  210  sends billing information to the data service node  500  so that the cost of the call can be billed back to the calling party. 
     In the architectures of FIGS. 1,  5  and  6 , all calls which are requested of the data service node  500  are routed through a single telecommunications switch  510 ,  540 ,  710  which appears at a single location in the PSTN  200 . In the architecture of FIG. 8, because the PSTN service node  210  is connected to and can select from among multiple geographically distributed telecommunications switches  220  of the PSTN  200  for call completion, the requested call can generally be routed more efficiently and at lower cost than in the architectures of FIGS. 1,  5  and  6 . 
     The architecture of FIG. 8 can be modified by providing multiple service nodes in the PSTN  200 . FIG. 9 illustrates an architecture in which a separate service node  230 ,  250 ,  270  is provided for each telecommunications switch  240 ,  260 ,  280 . Each data service node  500  can be programmed to send call origination requests to a respective one of the service nodes  230 ,  250 ,  270  of the PSTN to distribute the processing load across multiple service nodes. Each data service node  500  could be programmed with a prioritized list of service nodes  230 ,  250 ,  270  so that it can route call origination traffic to alternative service nodes if its preferred service node is unavailable. 
     Several alternative embodiments of the invention are described above. These and other variations are within the scope of the invention and are intended to be within the scope of the claims below.