Abstract:
An IPNT call center is provided wherein agent&#39;s computers may be locally-connected to a managing computer on a local area network, or remote agents may act over the Internet with the managing computer. The managing computer establishes an IPNT call with each remote agent on duty, and then routes incoming IPNT calls to the remote agents by substituting an incoming call for an existing call without closing the existing call, thereby avoiding the necessity of establishing a new call with the remote computer for each call routed to the remote agent. In some embodiments the IPNT system is a part of a multimedia call center, wherein incoming calls may be either IPNT or plain old telephony service (POTS), and calls are routed to agents according to a set of business rules without regard to type.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention in its several aspects presented herein is in the area of telephone communication in the broadest sense; that is, including all multimedia communication aspects of intelligent networks, call-center technology including computer-telephony integration (CTI), and Internet protocol telephony networks and related technology.  
         BACKGROUND OF THE INVENTION  
         [0002]    Telephone is one of the most widely used communication equipments in the world. At first, it was merely a convenient tool to allow people to communicate while they are physically separated. Recently, many companies use telephones to market products and services, provide technical supports to consumer products, allow customers to access their own financial data, etc. Thus, telephone is becoming a major business and marketing tool.  
           [0003]    In order to more effectively use telephone for business and marketing purposes, call centers have been developed. In a call center, a large number of agents handle telephone communication with customers. The matching of calls between customers and agents is typically performed by software. A simple example is used here to describe a few of the many advantages of using call centers. When a call is made to a call center, the telephone number of the calling line is typically made available to the call center by a telephone carrier. Based on this telephone number, the software in the call center can access a database server to obtain information about the customer who has been assigned that phone number. The software can now route the call to an agent who can best handle the call based on predefined criteria (e.g., language skill, knowledge of products the customer bought, etc.). The software immediately transfers relevant information to a computer screen used by the agent. Thus, the agent can gain valuable information about the customer prior to receiving the call. As a result, the agent can more effectively handle the telephone transaction.  
           [0004]    It can be seen from the above example that the enabling technology requires a combination of telephone switching and computer information processing technologies. The term commonly used for this combined technology is computer-telephony-integration (CTI).  
           [0005]    In recent years, advances in computer technology and telephony equipment and infrastructure as well has provided many opportunities for improving telephone service. Similarly, development of the information and data network known as the Internet together with advances in computer hardware and software has led to a new multi-media telephone system known in the art as Internet protocol network telephony (IPNT). In IPNT as well as in the older intelligent and CTI-enhanced telephony systems, both privately and publicly switched, it is desirable to handle more calls faster and to provide improved service in every way, including such improvements as video calls and conferencing.  
           [0006]    In various embodiments and aspects of the present invention described in enabling detail below, new and enhanced apparatus and methods are provided for improving telephony systems and service.  
         SUMMARY OF THE INVENTION  
         [0007]    In a preferred embodiment of the present invention a method for establishing a home agent from an Internet-connected call center is provided, comprising steps of (a) placing a first Internet Protocol Network Telephony (IPNT) call from a call-center managing computer to a PC at an agent&#39;s location remote from the call-center managing computer, thereby establishing an active IPNT call; (b) receiving a second IPNT call from a client at the call-center managing computer; and (c) substituting the second call for the first call as the active IPNT call. Third and subsequent calls may be connected to the remote agent by repeating the steps.  
           [0008]    In alternative embodiment local agents having PCs are connected to the call-center managing computer by a local area network (LAN), and plural home agents are established by opening IPNT calls to the plural home agents via the Internet, and wherein IPNT calls are routed to the local agents on the LAN and to the plural home agents without ending the connections to the home agents.  
           [0009]    In another aspect of the invention an Internet Protocol Network Telephony (IPNT) call center is provided, comprising a managing computer having a connection to a wide area network (WAN); and a plurality of agent stations at remote locations from the managing computer, a PC at each of the agent stations also connected to the Internet. In this embodiment the managing computer is adapted to establish a first IPNT call to one of the remote agent stations over the WAN, to receive a second IPNT call from a client while the first call is open, and to substitute the first call for the second call, thereby connecting the home agent with the client placing the second call. In a preferred embodiment the WAN is the Internet.  
           [0010]    In some embodiments the managing computer is further adapted to substitute third and subsequent calls for clients for the open call to the agent station, thereby connecting a series of calls from clients to the managing computer to the agent at the agent station. In systems with plural remote agents the managing computer is adapted to select remote agents to interact with client callers, and to connect incoming IPNT calls to any remote agent with whom an IPNT connection has been made. There may be local agent stations having PCs connected to the managing computer on a local area network, and the managing computer may be adapted to select agent stations to receive incoming calls, and to route incoming calls to agent stations without regard for whether the selected agent station is connected to the managing computer by LAN or WAN.  
           [0011]    In some embodiments the managing computer is a Computer Telephony Integration (CTI) processor in a multimedia call center, the CTI processor connected by a CTI link to a telephony switching apparatus having a wide band trunk for receiving telephone calls and plural station side ports connected to telephones at the local agent stations. In this embodiment incoming calls, both plain old telephone service (POTS) and IPNT calls, are routed to selected agents according to routing rules covering all incoming calls without preference to type, IPNT calls being transferred to PCs and telephone calls to telephones by manipulating the switching apparatus.  
           [0012]    The invention provides an IPNT-capable call center architecture wherein agents may be locally employed, or employed from their homes or remote businesses. Further, the maintenance of an open IPNT call and substituting incoming calls as business is completed on previous calls, provides for a system that is quicker than conventional systems, as new calls don&#39;t have to be established repeatedly with the same remote agent. Once an IPNT call is made, it need not be broken while the agent is on duty and disposed to interact with clients. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a block diagram of a video routing system of the present invention.  
         [0014]    [0014]FIG. 2 is a flow chart of a trunk route script which allows a host of the present invention to control the operation of a private branch exchange.  
         [0015]    [0015]FIG. 3 is a flow chart showing the operation of the video routing system of the present invention.  
         [0016]    [0016]FIG. 4 is a drawing showing the logical connection between components in a call station of the present invention.  
         [0017]    [0017]FIG. 5 is a block diagram of a voice and data communication system of the present invention.  
         [0018]    [0018]FIG. 6 is a block diagram of a computer-telephony-integration system of the present invention.  
         [0019]    [0019]FIG. 7 is a flow diagram showing the flow of events during an exemplary data and voice communication session conducted in accordance with the present invention.  
         [0020]    [0020]FIG. 8 is a block diagram of another computer-telephony-integration system of the present invention.  
         [0021]    [0021]FIG. 9 is a flow diagram showing the flow of events during another exemplary data and voice communication session conducted in accordance with the present invention.  
         [0022]    [0022]FIG. 10 is a drawing showing a call center architecture of the present invention.  
         [0023]    [0023]FIG. 11 is a flow chart showing an embodiment of the present invention.  
         [0024]    [0024]FIG. 12 is a block diagram of a prior art call center architecture.  
         [0025]    [0025]FIG. 13 is a block diagram of a multiple call center&#39;s architecture of the present invention.  
         [0026]    [0026]FIG. 14 is a schematic diagram showing illustrating objects used in a stat-server of the multiple call centers system of the present invention.  
         [0027]    [0027]FIGS. 15A and 15B (in combination) is a flow diagram showing the operation of a multiple call centers system in accordance with the present invention.  
         [0028]    [0028]FIG. 16 is a schematic diagram of a call center system containing a central controller of the present invention.  
         [0029]    [0029]FIG. 17 is a schematic diagram of an individual call center of the present invention.  
         [0030]    [0030]FIG. 18 is a timing diagram showing a time interval when the estimation algorithm in accordance with the present invention is needed because no actual data is available.  
         [0031]    [0031]FIG. 19 is a block diagram of a call center that can implement the multiple object state determination system of the present invention.  
         [0032]    [0032]FIG. 20 is a schematic diagram illustrating objects used in a stat-server of the multiple call centers system of the present invention.  
         [0033]    [0033]FIG. 21 is a block diagram showing an e-mail processing center of the present invention.  
         [0034]    [0034]FIG. 22 is a block diagram of a e-mail to CTI server adapter used in the e-mail processing center of the present invention.  
         [0035]    [0035]FIG. 23 is a flow chart showing the operation of the e-mail processing center of FIG. 20. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    Video Telecommunication Routing Systems and Methods ( 3215 )  
         [0037]    The present invention comprises a novel video telecommunication routing system and related methods. The following description is presented to enable any person skilled in the art to make and use the invention. Description of specific applications is provided only as examples. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0038]    [0038]FIG. 1 is a block diagram of a video routing system  100  of the present invention. System  100  comprises a video kiosk  102  which originates a video call and a call center  110  which accepts and assigns an appropriate video agent to process the call. Video Kiosk  102  and call center  110  are connected to a public-switched telephone network (PSTN)  104  via telephone lines  106  and  107 , respectively. As will be explained below, line  106  is preferably a basic rate interface and line  107  is preferably a primary rate interface. Consequently, video calls between video kiosk  102  and call center  110  are carried by PSTN  104 .  
         [0039]    Call center  110  comprises a video routing device  111  which accepts calls (including video calls) when predetermined phone numbers are dialed, and then routes individual call to one of a plurality of stations in accordance with predefined criteria. These stations include video stations  115 - 117 . In an embodiment of the present invention, the criteria could vary in real time as the characteristics of the calls and video stations change.  
         [0040]    It is possible for call center  110  to process video calls from other video kiosks, such as kiosk  103 . Call center  110  may also process conventional voice calls.  
         [0041]    In one embodiment of the present invention, video stations  115 - 117  can be connected to a communication network  121 . This network could be a local area network commonly used in many offices. Other devices, such as a database server  122 , can also be connected to network  121 . Information of video stations, call center personnel and customers can be stored in database server  120 . This information is accessible by video stations  115 - 117 . It should be appreciated that database server  120  does not have to be a sophisticated database management system. It could be as simple as a table stored in a small data processing device. Video routing device  111  may optionally be connected to database server  120  so as to access the information. This information can also be stored inside video routing device  111 .  
         [0042]    An example of the types of video telecommunication that can be advantageously handled by routing system  100  is intelligent routing of a video conference between a customer located at video kiosk  102  and an appropriate agent sitting by one of the video stations in call center  110 .  
         [0043]    Video routing device  111  comprises a switching device  112  for accepting calls from PSTN  104 . Switching device  112  could be a automatic call distributor (ACD)/private branch exchange (PBX) or a PSTN switch. It should be appreciated that switching device  112  (hereinafter “ACD/PBX  112 ”) can be a customer premise equipment or may be provided by a telephone communication carrier. ACD/PBX  112  contains a high bandwidth port  144  (for connecting to PSTN  104 ) and a plurality of low bandwidth ports (such as ports  146 - 150 ). Some of these ports can be connected to video stations  115 - 117 . The other low bandwidth ports can be connected to voice-based devices. Each of the low bandwidth ports is assigned one or more directory numbers. In one embodiment of the present invention, two directory numbers (corresponding to two telephone channels) are assigned to a video station.  
         [0044]    ACD/PBX  112  is also connected to a CTI/PBX server  113  through a computer-telephony-integration (CTI) link  123 . Video routing device  111  comprises two other servers: a routing server/video ACD  114  for routing video calls and a stat-server  124  for storing historic information of call center  110 . CTI/PBX server  113  functions as an interface between these two servers and ACD/PBX  112 . These three servers are connected to communication network  121 . In the present embodiment, the function of these servers are provided by software modules. As explained below, these three servers can be used in combination with a conventional ACD/PBX to achieve the video routing function of the present invention.  
         [0045]    High bandwidth port  144  of ACD/PBX  112  is preferably connected to a high capacity telephone line, such as a primary rate interface (PRI) as defined in the CCITT ISDN 1.431 standard. This is one of the standards of the international ISDN protocol. Low bandwidth ports  146 - 145  could be a single voice channel or a basic rate interface (BRI) as defined in CCITT ISDN 1.430 standard. Basically, BRI offers two 56 kilo-bit-per-second (Kbps) user data channels (the “bearer” or B channels) and one 16 Kbps signaling channel (the D channel). This interface is also referred to as 2B+D. The combined bandwidth is 128 Kbps. The PRI offers twenty three user data channels and one 64 Kbps signaling channel. This interface is also referred to as 23B+D.  
         [0046]    In order to deliver video information at an acceptable level of quality (e.g., 15 frame per second), current compression technology prefers a bandwidth of at least 112 to 128 Kbps. This amount of bandwidth cannot be provided by a single telephone channel but could be provided by an ISDN BRI. Thus, in FIG. 1, line  106  connecting video kiosk  102  to PSTN  104  is preferably a BRI line.  
         [0047]    As discussed above, a BRI line essentially comprises two telephone channels. These two telephone channels must be connected to the same low bandwidth port of PBX 142 in order to allow all the video data from video kiosk 102 to be transmitted to the same video station. A conventional PBX does not have the ability to recognize that two telephone channels originated from the same video kiosk. Thus, it is not possible for it to connect them to the same video station.  
         [0048]    In one embodiment of the present invention, the servers in video routing device  111  (i.e., CTI/PBX server  113 , stat-server  124  and routing server/video ACD  114 ; these three servers are collectively called the “host”) are used in combination with a conventional PBX to route calls originated from video kiosk  102  to the appropriate low bandwidth port. In this embodiment, ACD/PBX  112  is a conventional PBX which comprises a data processing device capable of executing an internal trunk route script. This script contains a plurality of commands which control the operation of ACD/PBX  112 . For example, the script can connect calls received at high bandwidth port  144  to low bandwidth ports in accordance with certain criteria, determine the type of music or announcement to play when a call is put on hold, select the strategy to queue calls when all low bandwidth ports are busy, etc.  
         [0049]    In this embodiment of the present invention, the above described servers are used to determine the operation of ACD/PBX  112  (i.e., the internal trunk route script is essentially disabled). As a result, intelligence and routing decisions are moved from ACD/PBX  112  to the host. FIG. 2 is a flow chart  200  showing a trunk route script which allows the host to control the operation of ACD/PBX  112 . ACD/PBX  112  receives an incoming call (step  202 ). ACD/PBX  112  places a request to the host for routing the call (step  204 ). ACD/PBX  112  then waits for a response from the host (step  206 ). If it receives a response from the host, control is transferred to host, which then performs routing operation in accordance with criteria determined by the host (step  208 ). Flow chart  200  then ends, and another call can be processed by ACD/PBX  112  and the host. If ACD/PBX  112  does not receive a response from the host, it determines whether a response timeout (e.g., 10 seconds) has elapsed (step  210 ). If the answer is yes, ACD/PBX  112  then executes its internal script (step  212 ). Thus, the internal script provides a default routing routine for the call center. Flow chart  200  then ends, and another call can be processed by ACD/PBX  112  and the host. If the answer is no, ACD/PBX  112  continues to wait (i.e., flow chart  200  branches back to step  206 ).  
         [0050]    In the preferred embodiment of the present invention, video routing is performed by combining the resources of stat-server  124 , routing server/video ACD  114 , and CTI/PBX server  113 . Stat-server  124  contains a database for storing all relevant activities of call center  110  (e.g., the current status and history of activities of all low bandwidth ports). Routing server/video ACD  114  routes calls to appropriate low bandwidth ports based on factors such as the information contained in stat-server  124 , the information delivered by ACD/PBX  112  and the status of various low bandwidth ports. CTI/PBX server  113  acts as a bridge between ACD/PBX  112  at one end and stat-server  124  and routing server/video ACD  114  at the other end. CTI/PBX server  113  is designed to interface with PBXs manufactured by different vendors and present a uniform application program interface (API) to stat-server  124  and routing server/video ACD  114 . An advantage of this arrangement is that individual components in video routing device  111  could be replaced and enhanced separately. For example, substantially the same routing server/video ACD and stat-server could be used with PBXs from different manufacturers by changing CTI/PBX server  113 .  
         [0051]    The operation of an embodiment of video routing system  100  is now described in connection with flow chart  250  of FIG. 3. The video routing system in this embodiment operates in a telephone system in which two separate telephone numbers are associated with an ISDN channel. It should be note that this embodiment can be modified in a manner described below to function in a telephone system in which only one telephone number is associated with an ISDN channel.  
         [0052]    In system  100 , a regular toll-free 800-number is pre-assigned to carry video information. Thus, video kiosk  102  dials this number twice, each time using a different phone number associated with the ISDN channel (step  252 ). The time gap for connecting these two calls to call center  110  by PSTN  104  ranges from less than a second to several seconds. Typically, the gap is below one minute.  
         [0053]    PSTN  104  connects the calls to call center  110  (step  254 ). Each time when the 800-number is dialed, PSTN  104  delivers two pieces of information to ACD/PBX  112 : a “dial number identification system” (DNIS) for uniquely identifying the toll-free 800-number and an “automatic number identification” (ANI) for uniquely identifying the telephone line which originates the call. In this embodiment, the above described toll free 800-number and the ISDN line connected to video kiosk  102  are pre-assigned for video conference purposes. The DNIS and ANIs of the corresponding 800-number and ISDN line should have been previously stored in a database (which could be located in routing server/video ACD  114  or database server  120 ).  
         [0054]    In the present invention, ACD/PBX  112  transfers control of calls to the host (step  258 ). When ACD/PBX  112  receives the DNIS and the first of two ANIs from PSTN  104 , it sends these two numbers to CTI/PBX server  113 , which in turn sends them to routing server/video ACD  114 . Routing decision is not made by ACD/PBX  112 . Because this DNIS is one of the numbers recognized by routing server/video ACD  114  to be associated with a video call, the video routine algorithm of routing server/video ACD  114  is invoked. This serves as a convenient method for screening out non-video calls.  
         [0055]    Routing server/video ACD  114  then determines if this is a new video call or a part of an existing video call (step  260 ). It branches to a “DN-Relate” database. An example of a DN-Relate database is shown in Table 1:  
                                     TABLE 1                           DN-Relate            DN1#   DN2#   Status   Time Stamp   Related ANI               1000   1001   Available    9:20           1040   1041   Unavailable   10:10       1060   1061   Waiting   10:32   1213                  
 
         [0056]    It should be appreciated that the format and information contained in table  1  is for illustrative purposes only. The design of the table can be easily changed and enhanced by persons of ordinary skill in the art.  
         [0057]    In table 1, the entries under the columns “DN1#” and “DN2#” correspond to the pairs of directory numbers assigned to video stations. Each pair of directory numbers will be connected to the same video station. The column entitled “status” indicates the status of the directory numbers. If the entry is “unavailable,” these directory numbers are not available (e.g., video station not yet logged in) and should not be connected to a new video call. If the entry is “available,” these directory numbers could be used to connect to a new video telecommunication. If the entry is “waiting,” one of the two ANIs has been received, and a second ANI needs to be received to complete the video telecommunication. The entries under “time stamp” contain time-related information. This information could be used as part of the input variables of a routing algorithm, e.g., the video station waited longest for a video call should be connected first. The entries under “Related ANI” contain the second of two ANIs used for completing a video connection. The entries of this column can be used by routing server/video ACD  114  to connect appropriate video calls to the correct video station.  
         [0058]    The last row in table 1 is now explained. The numbers 1060 and 1061 under DN1# and DN2#, respectively, correspond to the directory numbers assigned to the same video station. The status is “waiting,” indicating that one of the directory numbers, e.g., 1060 under DN1#, has previously been connected to an incoming video call and this video station is waiting for the second incoming video call. The time under time stamp corresponds to the time the first call is received. The number under “related ANI”, i.e., 1213, corresponds to the ANI of the anticipated second call. The method of entering the anticipated ANI in table 1 will be explained below.  
         [0059]    Routing server/video ACD  114  compares the ANI obtained from ACD/PBX  112  to the ANIs stored in the DN-Relate database (step  262 ). If there is a match, routing server/video ACD  114  knows that this video call relates to an existing call. For example, if the received ANI is 1213, the database in table 1 indicates that video routing system  100  is waiting for this ANI to complete a video connection, and this call should be routed to DN# 1061. The status column of the corresponding row should be updated to indicate that video telecommunication has been established (step  264 ). Routing server/video ACD  114  then connects the video call to the waiting directory number (i.e., the corresponding entry under DN2#) indicated in the database (step  266 ). Flow chart  250  ends and another call can be processed.  
         [0060]    If routing server/video ACD  114  does not find any match, it needs to look for an available video station (step  270 ). It checks to see if a video station is available (step  272 ). Assuming that more than one video stations are available, one of them will be selected in accordance with predetermined criteria. For example, the time stamp column of a pair of available directory numbers indicates the time this pair of directory numbers first became available. This information could be used as a factor to select the appropriate video station. After an available video station is selected, routing server/video ACD  114  updates the status of this station (step  280 ). Specifically, it sets the corresponding status to “waiting” and sets the time stamp in the database. Routing server/video ACD  114  then connects the incoming call to the directory number (under “DN1#”) of the selected video station (step  282 ).  
         [0061]    Routing server/video ACD  114  needs to obtain the corresponding ANI for the remaining call (step  286 ). It jumps to a “ANI-relate” database. This database contains entries of the pairs of phones numbers associated with the ISDN lines assigned for video telecommunication purposes. For example, if a first ISDN line (connected to a first video kiosk) associates with ANIs 1212 and 1213 while a second ISDN line (connected to a second video kiosk) associates with ANIs 3726 and 3727, the ANI-relate database would have entries shown in Table 2:  
                             TABLE 2                           ANI-Relate                First ANI   Second ANI                       1212   1213           1213   1212           3276   3277           3277   3276           (Other pairs of ANIs)                      
 
         [0062]    It should be appreciated that the format and information contained in table 2 is for illustrative purposes only. The design of the table can be easily changed and enhanced by persons of ordinary skill in the art.  
         [0063]    As an example, if the ANI received by routing server/video ACD  114  is 3276, the ANI-Relate database indicates that the ANI associated with the same video call is 3277. Thus, routing server/video ACD  114  is able to obtain the second of a pair of ANIs associated with a video connection. It then returns to DN-Relate database (see table 1) and places the number 3277 under the column “related ANI” of the selected video station. Routing system  100  then waits for incoming calls having this second ANI. Flow chart  250  ends and waits for the next call.  
         [0064]    If there is no available video station, routing server/video ACD  114  sends the call to a queue to wait for an available station (step  292 ). In the present invention, a new method is used to queue video calls. This method is different from those used on standard voice calls. As stated earlier a call cannot be connected to one point and then disconnected to another point. Such operation will destroy the call. As a result, the new method, described below, is needed to handle the queuing.  
         [0065]    In step  294 , routing server/video ACD  114  checks to see if the video call has been in the queue for longer than an allowed time (i.e., the timeout period). If the allowed time has expired, routing server/video ACD  114  records the ANI that attempts to call the call center (step  296 ). When a video station is later available, this ANI can be retrieved by a video agent and a call can be placed by that video agent to the kiosk (or person) which had originated the call. In the mean time, ACD/PBX  112  is instructed to disconnect the video call and return a busy signal (step  298 ). This is the least desirable option. It should be used when no video agents are available and none are seen to become available within a relatively short time frame. The timeout period is set to reflect this consideration.  
         [0066]    If the video call has been in the queue for shorter than the allowed time, routing server/video ACD  114  continues to try to connect the call (step 302). That is, flow chart  250  loops back to step  272 . During this period of time, the video call remains in a ringing state. The loop continues until the timeout has elapsed. At that time, steps  296  and  298  are executed.  
         [0067]    It can be seen from the above description of flow chart  250  that video routing device  111  is able to receive video calls and connect them to appropriate video stations (if available) in call center  110 . Video routing device  111  could also access database server  120 , if there is a need to do so, to obtain additional information about video kiosk  102  and the video station selected for connection. This information can be sent to an agent monitoring the selected video station.  
         [0068]    As pointed out above, video routing device  111  can also be used for the situation where only one phone number is assigned to an ISDN channel. In this case, there is no need to generate the “ANI-relate” database because the entries in the first and second columns will be the same. The calling ANI is directly written to the appropriate row of the “related ANI” column. This is because the calling ANI and the anticipated second ANI are the same.  
         [0069]    [0069]FIG. 4 is a drawing showing the logical connection between components in call center  110 . It can be seen from FIG. 4 that ACD/PBX  112  is connected only to CTI/PBX  113 . Information regarding calls is communicated to stat-server  124  by CTI/PBX  113  so that stat-server  124  can record all telephone transactions. CTI/PBX server  113  is also connected to routing server/video ACD  114  for allowing it to route video calls. Routing server/video ACD  114  is connected to stat-server  124  because the information stored therein is used by routing server/video ACD  114  to route calls. Further, stat-server  124  records routing instructions of routing server/video ACD  114 . Routing server/video ACD  114  is also connected to database server  120  to obtain additional information for routing calls. Stat-server  120  and database server  120  are connected so that information contained therein can be shared and updated.  
         [0070]    Video stations  115 - 117  are connected to routing server/video ACD  114  so that video calls can be routed thereto. Video stations  115 - 117  are also connected to database server  120  so that information regarding customers, products, etc., can be downloaded from database server  120 .  
         [0071]    It should be appreciated that even though CTI/PBX  113 , routing server/video ACD  114 , stat-server  124  and database server  120  are shown as separate components, they could be combined into one, two or three components residing on one or more data processing devices.  
         [0072]    Apparatus and Methods for Coordinating Telephone and Data Communications ( 3216 )  
         [0073]    The present invention comprises a novel system and related methods for coordinating telephone and data communications. The following description is presented to enable any person skilled in the art to make and use the invention. Description of specific applications is provided only as examples. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0074]    [0074]FIG. 5 is a block diagram showing a voice/data communication system  1100  operating in accordance with the present invention. System  1100  comprises a provider site  1102  and a customer site  1104  connected by a data communication network  1106 , such as the Internet. It should be appreciated that the Internet is used here as an exemplary data communication network, and the present invention is not limited to be used in Internet. In this embodiment, provider site  1102  and customer site  1104  are engaged in electronic commercial transactions. Thus, provider site  1102  sends (via Internet  1106 ) product information, order forms, confirmation notices, etc. to customer site  104  and customer site  1104  sends in (again via Internet  1106 ) orders, shipping address, and payment information, etc. to provider site  1102 . In this system, provider site refers generally to a location which sells information, products or services and customer site refers to a location which requests such information, products or services. A plurality of others provider site, such as provider site  1108 , and a plurality of other customer sites, such as customer site  1110 , are also connected to Internet  1106 .  
         [0075]    It should be appreciated that the present invention relates to coordinating data and telephone communications between any two sites. The description of provider sites and customer sites pertains to an important (but not the only) application of the present invention envisioned by the inventor. The present invention can be applied to many applications.  
         [0076]    Customer site  1104  comprises a client computer  1114  running a browser  1116  of the present invention. Client computer  1114  is connected to a modem  1122  which is coupled to a TCP/IP connection  1124 . As a result, client computer  1114  is able to gain access to the Internet  1106 . A user in customer site  1104  use browser  1116  to communicate with other computers connected to Internet  1106 .  
         [0077]    Customer site  1104  also contains a telephone  1128  which allows the user in customer site  1104  to make telephone communication with a service agent in provider site  1102 . Telephone  1128  is coupled to a public switched telephone network (PSTN)  1160  via a telephone channel  1162 . In the prior art system, it is not possible for the system to coordinate voice (via PSTN  1160 ) and data (via Internet  1106 ) communication between the user and the service agent. One aspect of the present invention allows such coordination to take place. As a result, the user and the service agent can display the same data (e.g., the same web page) at their respective computer screens and communicate orally (or visually if picture-phones are installed in both sites) at the same time.  
         [0078]    Provider site  1102  comprises a server  1132  connected to Internet  1106  through a TCP/IP connection  1134 . Server  1132  supplies various web documents (e.g., product information, order forms, etc.) to browsers that request the documents. Provider site  1102  contains a service assistance center  1140  in which a number of service agents can take telephone calls from users in various customer sites. Service assistance center  1140  contains a computer-telephony-integration (CTI) system  1142  for accepting calls from PSTN  1160  and routing calls to a plurality of telephones, one of them is shown as telephone  1144 . Service assistance center  1140  also contains a plurality of computers, one of them is shown as computer  1146 . CTI system  1142  is coupled to PSTN  1160  via a high bandwidth telephone channel  1164 , such as a primary rate interface (PRI) as defined in the CCITT ISDN 1.431 standard. The service agents use both the computers and telephones to efficiently provide services to various users in the customer sites.  
         [0079]    It should be appreciated that the CTI system  1142  is not limited to route voice communication. It can also route other types of communication. A CTI system that can route video calls has been disclosed in a copending patent application entitled “Video Telecommunication Routing Systems and Methods” filed Oct. 25, 1995 in the names of Alec Miloslavsky and Jason Goecke. This copending patent application is hereby incorporated by reference. It should also be appreciated that service assistance center  1140  and provider site  1102  can be in different physical locations, as long as they are electrically connected in the manner described below.  
         [0080]    The Internet side of the invention is first described. Browser  1116  is a piece of software that can display information sent by server  1132 . A protocol for communication between customer site  104  and provider site  1102  using Internet  1106  is the HTTP or web protocol. One of the advantages of web protocol is that the display on browser  1116  is a graphic document (commonly called a web page) containing text, images, and other information. Each web page has an address in a recognized format—the URL, or Uniform Resource Locator—that enables computers all over the world to access it. Browser  1116  sends a request to the URL of a web page in server  1132 . Server  1132  respond with a file encoded in a special language called the hypertext markup language (HTML). This language contains “tags” which allows a programmer to specify the appearance of the web page and set up hyperlinks to other HTML documents (located in the same or other servers). As a result, the user in customer site  1104  is able to use browser  1116  to access information in server  1132 .  
         [0081]    The web protocol also contains various mechanisms, e.g., common-gateway-interface (CGI), POST and GET methods, etc., for browser  1116  and server  1132  to communicate with each other. As a result, it is possible to design a system for the user in customer site  104  to place orders through the web page. For example, the user can click on an icon on a web page to order a product associated with the icon. Server  1132  receives and processes the order. This is one of the methods for carrying out electronic commercial transactions.  
         [0082]    When the user in customer site  104  is reviewing information on browser  1116  or is about to place an order, the user may request the attention of a service agent in service assistance center  1140 . For example, the user may want to ask additional information or provide confidential information (such as a credit card number) orally to the service agent. It is desirable for the service agent to display on his/her computer  1146  the same web page displayed on browser  1116  while interaction with the user through telephone. It is also desirable for the service agent to obtain as much information about customer site  1104  as possible prior to commencing telephone communication with the user.  
         [0083]    In the prior art methods, the user has to look up the telephone number of the service assistance center and manually call the center. After connected to a service agent, the user has to explain his/her needs, and if necessary, describe to the agent the web page being displayed on the browser. The service agent needs to identify the user and may have to access the server to find the web page displayed on the user&#39;s computer. It can be seen that this method is very slow and ties up valuable time of a service agent. As a result, prior art service assistance centers require many service agents in order to provide adequate service to customers.  
         [0084]    One aspect of the present invention provides automatic coordination between the telephone communication and the Internet communication. As an example, when the telephone communication is established, the web page displayed by browser  116  is automatically displayed on computer  1146  together with information about customer site  1104 . As a result, the service agent may anticipate the user&#39;s needs and immediately provides desired services to the user. It should be appreciated that telephone communication in the present system includes voice and/or video communication through PSTN  1160 .  
         [0085]    In the present invention, the web page originated from server  1132  contains an icon, such as a button  1118 , positioned at a convenient location of the web page. This icon is displayed by browser  1116 . When the user wishes to initiate telephone communication with service assistance center  140 , he/she can click on (i.e., select) button  118 . There is no need for the user to look up the telephone number of service assistance center  1140 . One way for browser  1116  to display a clickable button  1118  is by embedding (at the appropriate place in the associated HTML document) a tag of the form: &lt;A HREF=“phone.html”&gt;&lt;IMG src=“HTTP://“button.gif”&gt;&lt;/A&gt;. In this example, “button.gif” is the URL addresses of a graphic file (in a popular graphic format called GIF) associated with the button icon and “phone.html” is the URL address of a file which can respond to the clicking. This tag tells a browser to display the “button” image (which is preferably stored in server  1132 ), and to treat it as a clickable item that, whenever a user clicks on it with a mouse, triggers a connection to the file “phone.html” (also preferably stored in server  1132 ).  
         [0086]    When button  1118  is clicked, browser  1116  sends a telephone service request to “phone.html” in server  1132 . Server  1132  then sends the request and associated data (e.g., the identity of customer site  104  and the HTML document associated with the web page displayed on browser  1116 ) to a service request process (SRP)  1168 . SRP  1168  is a software module which could run on server  1132  or on a separate data processing device. SRP  1168  selects an available service agent in accordance with predetermined criteria (e.g., availability of agents, previous interaction between a certain agent and customer site  1104 ). Assuming that the service agent associated with computer  1146  is selected, the HTML document previously sent to customer site  1104  is delivered to computer  1146 . Computer  1146  contains a browser and can display the HTML document. As a result, the service agent who will interact with the user in customer site  1104  is able to see the same web page the user is seeing. As explained below, other information about customer site  1104  can also be sent to computer  1146 . This information is accessible by the service agent.  
         [0087]    One aspect of the present invention is a CTI system that can provide a telephone connection between the user and the service agent associated with computer  1146 . FIG. 2 shows a block diagram of CTI system  1142  which works with SRP  1168  to provide such a connection. Reference numerals in FIG. 6 that are the same as that for FIG. 5 refer to the same elements.  
         [0088]    CTI system  1142  comprises a switching device  1202  for accepting calls from PSTN  1160 . Examples of switching device  1202  are (but not limited to) an automatic call distributor (ACD)/private branch exchange (PBX) and a PSTN switch. It should be appreciated that switching device  1202  (hereinafter “PBX  202 ”) can be a customer premise equipment or may be provided by a telephone communication carrier. PBX  1202  contains a high bandwidth port  1204  (for connecting to PSTN  1104 ) and a plurality of low bandwidth ports (such as ports  1206 - 1209 ). Each of the low bandwidth ports is assigned one or more directory numbers. Some of these ports can be connected to telephones used by service agents (such as telephones  1213  and  1216 ).  
         [0089]    In order to facilitate the operation of service agents, each agent has easy access to a telephone and a computer. In FIG. 6, a telephone and a computer is set up as a station and assigned to a service agent. For example, telephone  1213  and a computer  1214  is grouped as a station  1215  while telephone  1216  and a computer  1217  is grouped as a station  1218 . When a service agent logs in, he/she can enter his/her identification information to computers  1214  and  1217 , respectively. As explained above, information on the service agents (such as language skill, knowledge of products, etc.) could be used by SRP  1168  as some of the factors in selecting an appropriate service agent to interact with a particular user.  
         [0090]    PBX  1202  is connected to a CTI server  1222  through a CTI link  1220 . CTI system  1142  also comprises a stat-server  1224  and a routing server  1226 . Stat-server  1224  stores all relevant activities of CTI system  1142  (e.g., the current status and history of activities of all low bandwidth ports). Routing server  1226  routes calls to appropriate low bandwidth ports based on factors such as the information contained in stat-server  1224 , the information delivered by PBX  1202  and the status of various low bandwidth ports. CTI system  1142  contains a database server1  228  containing information of provider site  1102 , e.g., agent skills, and information pertaining to the customers of provider site  1102 , including information of customer site  1104 . CTI system  1142  also contains an external router  1230 , working together with SRP  1168 , for reserving a specific telephone channel between customer site  1104  and the telephone in the station of the selected service agent. The detail operation of external router  1230  will be described below.  
         [0091]    One function of CTI server  1222  is to act as a bridge between PBX  1202  at one end and stat-server1  224 , external router  1230  and routing server  1226  at the other end. CTI server  1222  is designed to interface with PBXs manufactured by different vendors and present a uniform application program interface (API) to stat-server  1224 , external router  1230  and routing server  1226 . An advantage of this arrangement is that individual components in CTI system  1142  could be replaced and enhanced separately. For example, substantially the same routing server, external router and stat-server could be used with PBXs from different manufacturers (e.g., AT&amp;T, Northern Telecom or Ericsson) by changing CTI server  1222 . Specifically, different versions of a particular implementation of CTI server  1222  can be designed to match with switches made by different manufacturers (provided that the switches have a CTI link). These versions communicate with the same routing server, external router and stat-server through a standard protocol which is switch-independent.  
         [0092]    In one embodiment of the present invention, stat-server  1224 , external router  1230 , routing server  1226 , external router  1230 , and computers  1214  and  1217  are connected to a communication network  1234 . In the present embodiment, the function of these servers and external router  1230  are provided by software modules running in one or more computers. It should be appreciated that even though CTI server  1222 , routing server  1226 , stat-server  1224 , external router  1230  and database server  1228  are shown as separate components, they could be combined into one, two, three or four components residing on one or more data processing devices.  
         [0093]    SRP  1168  is connected to external router  1230  and communication network  1234 . After a user in customer site  1104  clicks on button  1118  and issues a request, SRP  1168  determines the status of the agent computers (e.g., whether computers  1214  and  1217  have been turned on) and the identity of agents in the stations. SRP  1160  may need to access database server  2128  and stat-server  1224  to obtain the necessary information. SRP  1168  then selects an appropriate agent and notifies external router  1230 . External router  1230  selects a telephone number of a routing point of PBX  1202  and associate this telephone number with the directory number of PBX  1202  which connects to the telephone of the selected service agent. The routing point is a component in PBX  1202  which generates a CTI redirect request to CTI server  1222  whenever a call reaches this component. This routing point could be a control directory number, virtual directory number, or a trunk/dial number identification system (DNIS). The exact nature of the telephone number is not important, as long as it is a number which can reach the routing point. Thus, the telephone number could be a private network number, a public network number or an international number.  
         [0094]    External router  1230  notifies CTI server  1222  and SRP  1168  of this telephone number. SRP  1168  causes server  1132  to send this telephone number to browser  1116  in customer site  1104 . Browser  1116  can either display this number so that the user can dial it manually or dial the number electronically and notifies the user about the status of the telephone connection. When PBX  1202  receives a call having this telephone number, it directs the call to CTI server  1222 . CTI server  1222  sends the call to external router  1230 , which then delivers this call to the directory number associated with the selected service agent.  
         [0095]    PBX  1202  keeps a number of such routing points specifically reserved to accommodate requests from SRP  1168 . These routing points are used as “semaphores” by SRP  1168 . They are allocated and deallocated as needed. Once a routing point is reserved by SRP  1168  for a particular service agent, it is considered unavailable. Once the call is routed to the service agent, the routing point is again usable.  
         [0096]    [0096]FIG. 7 is a flow diagram showing the flow of events during an exemplary data and voice communication session using the CTI system shown in FIG. 6. In FIG. 7, operations are grouped under three columns  1306 - 1308  indicating the locations in which the operations take place: customer site, server/SRP and service assistance center. When a session starts, browser  1116  in customer site  1104  sends a URL to server  1132  (operation  1310 ). Server  1132  responds by sending browser  1116  a HTML document (operation  1312 ). This document contains a tag causing browser  1116  to display a clickable button. Browser  1116  receives the HTML document and creates a web page based on the HTML document (operation  1314 ). After reviewing the displayed web page, the user clicks on button  1118 . Browser  1116  responses by sending a request for an agent (together with data identifying customer site  1104 , if needed) to server  1132  (operation  1316 ). Server  1132  delivers the request and the data to SRP  1168 , which in turn delivers the information to external router  1230  (operation  1320 ). External router  1230  selects a service agent. It reserves a telephone number and associates it with a telephone used by the selected service agent. This telephone number is sent to SRP  1168  (operation  1324 ). At this time, the service agent receives information regarding customer site  1104  and the HTML documents previously sent to browser  1116  (operation  1325 ). The telephone number received by SRP  1168  is sent to server  1132 , which in turn sends the number to browser  1116  (operation  1326 ). Browser  1116  (or the user) then dials the telephone number so as to establish telephone connection to the selected service agent (operation  1330 ). As pointed out above, this telephone number causes PBX  1202  to route the call to the directory number associated with the selected service agent. The service agent receives the telephone call (operation  1332 ). At this time, the service agent has already acquired a lot of information about customer site  1104  and the web pages previously delivered thereto.  
         [0097]    Another embodiment of the present invention is now described. In this embodiment, call center  1102  initiates the telephone call (in response to a request by a user in customer site  104 ) instead of customer site  1104  initiates the telephone call. Referring now to FIG. 5, the user requests a telephone call by clicking on button  118  (which could be labeled a “call me” button). A dialog box appears. It asked the user to enter the telephone number of phone  1128 . Browser  1116  then sends the telephone number of phone  1128  to server  1132  in provider site  1102 . Alternatively, the telephone number could have been previously stored in computer  1114  (e.g., in the form of a persistent client state information commonly called the “cookies” in Internet technical literature). Server  1132  then sends the telephone number and associated data (e.g., the identity of customer site  1104  and the HTML document associated with the web page displayed on browser  1116 ) to SRP  1168 . SRP  1168  then requests service assistance center  1140  to call this telephone number and select an agent to talk with the user.  
         [0098]    Browser  1116  could send other identification information instead of the telephone number to server  1132 . For example, the name or Internet address of customer site  1104  could be sent. Server  1132  or SRP  1168  could maintain a customer list associating the identification information with the telephone number of phone  1128 . As a result, service assistance center  1140  could call telephone  1128  based on information on this customer list.  
         [0099]    Other information can also be sent by browser  1116 . For example, the user can specify a certain time period on a certain date as an appropriate time for receiving calls from service assistance center  1140 .  
         [0100]    [0100]FIG. 8 is a block diagram of a CTI system  1350  which can call telephone  1128  in accordance with the present invention. Reference numerals in FIGS. 6 and 8 that are the same refer to the same elements. It should be appreciated that a CTI system can be formed by combining elements in FIGS. 6 and 8 so as to allow either provider site  1102  or telephone  1128  to initiate the telephone call.  
         [0101]    In FIG. 8, SRP  1168  is connected to an outbound call controller  1354 , which is in turn connected to switching device  1202  and communication network  1234 . After SRP  1168  received the telephone number of phone  1128 , it deposits the number in a list server  1356 . This server is essentially a queue which contains all the telephones which needs to be dialed out by service assistance center  1140 . Typically, the queue is arranged in a first-in-first-out manner. However, it is possible to set up a different priority scheme for scheduling the calls.  
         [0102]    Outbound call controller  1354  dials the telephone numbers in list server  1356 . The progress of the call is monitored by a call progression detector (CPD)  1358 . Detector  1358  returns the status of the call (e.g., line busy, call received by a facsimile machine, call received by a modem, etc.). Outbound call controller  1354  takes appropriate actions based on this status, e.g., it can dial another number in list server  1356  if the telephone corresponding to a previously dialed number is busy.  
         [0103]    When the telephone number corresponding to phone  1128  is dialed and CPD  1358  determines that the line is not busy, outbound call controller  1354  requests routing server  1226  to find a free agent who is qualified to handle the call to customer site  1104 . SRP  1168  can then send the digital data (e.g, the HTML document displayed on the user&#39;s computer) to the selected agent. As a result, an agent in service assistance center  1140  is able to talk with a user in customer site  104  while reviewing the web page displayed on browser  1116  in customer site  1104 .  
         [0104]    In a different version of this embodiment, SRP  1168  can estimate the length of time for service assistance center  1140  to call telephone  1128  based on the number of telephone numbers already in list server  1356  and the availability of agents. If this length of time is excessively long, SRP  1168  may ask Internet server  1132  to send a message to browser  1116  informing the user of the estimated waiting time. The user has the freedom to request a rescheduling of the call.  
         [0105]    [0105]FIG. 9 is a flow diagram showing the flow of events during an exemplary data and voice communication session using the CTI system shown in FIG. 8. In FIG. 9, operations are grouped under three columns  1406 - 1408  (similar to that of FIG. 7) indicating the locations in which the operations take place: customer site, server/SRP and service assistance center. When a session starts, browser  1116  in customer site  1104  sends a URL to server  1132  (operation  1410 ). Server  1132  responds by sending browser  1116  a HTML document (operation  1412 ). This document contains a tag causing browser  1116  to display a clickable button. Browser  1116  receives the HTML document and creates a web page based on the HTML document (operation  1414 ). After reviewing the displayed web page, the user clicks on “call me” button  1118 . Browser  1116  responses by sending a request for a phone call, together with telephone number and/or data identifying customer site  1104 , to server  1132  (operation  1416 ). Server  1132  delivers the request and the telephone number to SRP  1168 , which in turn delivers the number to outbound call controller  1354  (operation  1420 ). The telephone number is placed in list server  1354  (operation  1424 ). Controller  1354  dials outbound phone calls from number is list server  1354  (operation  1426 ). When the user in customer site  1104  answers the call (operation  1430 ), an agent in service assistance center  1102  is assigned to handle the call (operation  1432 ). Data related to customer site  1104  and the web page viewed by the user is delivered to the agent. The agent can then answer the call with all necessary information on hand (operation  1434 ).  
         [0106]    Methods and Apparatus for Implementing a Network Call Center ( 3219 ) The present invention comprises a novel call center architecture and related methods. The following description is presented to enable any person skilled in the art to make and use the invention. Description of specific applications is provided only as examples. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0107]    [0107]FIG. 10 is a drawing showing a call center architecture  2100  of the present invention. Architecture  2100  contains a network provider call center  2102  and a customer call center  2104 . Network provider call center  2102  is maintained by an operator of a public-switched telephone network (PSTN)  2105 . Customer call center  2104  is linked to PSTN  2105  by a telephone link  2106 . Customer call center  2104  is also optionally linked to provider call center  2102  by a data connector  2172 . In this architecture, most of the equipments associated with the implementation of a call center are preferably located at provider call center  2102  while the agents are preferably located at customer call center  2104 .  
         [0108]    Network provider call center  2102  provides call center services to other customers, such as customer call center  2108 . These call centers are linked to PSTN  2105  by telephone links. For example, customer call center  2108  is linked to PSTN  2105  by telephone link  2109 . Further, customer call center  2108  is optionally connected to provider call center  2102  by a data connector  2174 .  
         [0109]    In order to illustrate the operation of the present invention, the system in FIG. 10 is used to perform predictive dialing. In this case, agents in customer call center  2104  want to contact potential buyers of a product or service. The telephone numbers of these potential buyers are stored in a database in provider call center  2102 . Equipments in provider call center  2102  dial these telephone numbers. If a telephone number is busy, another telephone number is dialed automatically. When a potential buyer answers the call, the call is immediately routed to an available agent in customer call center  104 . The agent can then talk to the buyer regarding the product or service.  
         [0110]    Customer call center  2104  comprises a private branch exchange and/or automatic call distributor (shown in FIG. 10 as PBX  2152 ) and a plurality of stations, such as stations  22154  and  2156 . Each station has a telephone (such as telephones  2158  and  2160  in stations  2154  and  2156 , respectively) and a computer (such as computers  2159  and  2161 ). The telephones are connected to PBX  2152 . The computers are connected to a local area network  2166 , which is in turn connected to data connector  2172 . Agents in customer call center  2104  are assigned to these stations to operate the telephones provided therein.  
         [0111]    Provider call center  2102  comprises a network switch  2110 , a CTI system  2112  and a computer predictive dialer  2114 . Network switch  2110  contains circuits that can provide switching and call distribution functions. Network switch  2110  is coupled to a high bandwidth telephone line  2116  so that a plurality of telephone channels are available for connecting to the telephones of potential buyers. Network switch  2110  also contains means for keeping an incoming call connected thereto continuously so that this incoming call can be routed at will to any lines controlled by network switch  2110  (referred herein as the “continuous connection” function). Network switches made by some manufacturers contain this means. For those network switches that do not contain this means, a “looped around” circuit  2120  can be used to provide the same continuous connection functionality. Looped around circuit  2120  comprises a pair of station trunks  2122  and  2124  in a network switch that are physically connected together. This arrangement allows an incoming call (originated from an agent in a customer call center) terminated at one of the station trunks, such as station trunk  2122 , to be continuously connected to network switch  2110 , as long as the call is not disconnected by the caller (i.e., the agent) who initiated the call. The means for keeping incoming calls connected and the looped around circuit are collectively called the “continuous connection means.” During the time the incoming call is connected to continuous connection means, network switch  2110  can communicate with the caller (i.e., the agent) at any time without the need to reestablish the telephone connection.  
         [0112]    [0112]FIG. 10 shows the structure of CTI system  2112 . It contains a CTI-server  2132 , a stat-server  2134 , a routing server  2136  and a database server  2138 . Stat-server  2134  contains a database for storing all relevant activities of CTI system  2112  (e.g., the current status and history of all calls in CTI system  2112 ). Database server  2138  contains information of customer call center  2104 , such as information on various agents who work in customer call center  2104 . Routing server  2136  routes calls to appropriate stations in customer call center  2104  based on factors such as the information contained in stat-server  2134  and the status of various stations in customer call center  2104 . CTI-server  2132 , stat-server  2134 , routing server  2136  and database server  2138  are connected by a data communication network  2140 . Data connectors  2172  and  2174  connect data communication network  2140  to the local area networks in customer call centers  2104  and  2108 , respectively (such as local area network  2166  in center  2104 ).  
         [0113]    CTI server  2132  acts as a bridge between network switch  2110  at one end and stat-server  2134  and routing server  2136  at the other end. CTI server  2132  is designed to interface with network switches manufactured by different vendors and present a uniform application program interface (API) to stat-server  2134  and routing server  2136 . An advantage of this arrangement is that individual components in provider call station  2102  could be replaced and enhanced separately. For example, substantially the same routing server and stat-server could be used with network switches from different manufacturers (e.g., AT&amp;T, Northern Telecom or Ericsson) by changing CTI server  2132 . Specifically, different versions of a particular implementation of CTI server  2132  can be designed to match with switches made by different manufacturers (provided that the switches have a CTI link). These versions communicate with the same routing server, database server and stat-server through a standard protocol which is switch-independent.  
         [0114]    In operation, when an agent begins work at one of the stations in customer call center  2104 , such as station  2154 , he dials a predetermined telephone number which terminates at network switch  2110 . When network switch  2110  receives this call, it connect the call to the continuous connection means. For the network switches that contains loop around circuit  2120 , the call is connected to station trunk  2122 . As a result, telephone  2158  in station  2154  is connected to network switch  2110  until the agent terminates the call. The agent can also send his identification number and other information to routing server  2136  using telephone  2158  or computer  2159 . At this time, CTI system  2112  knows that station  2154  is now in operation and the identity of the agent in station  2154 . CTI system  2112  can route calls to this station. Other agents can log on to the system using the same method.  
         [0115]    In order to illustrate an application of the present invention, predictive dialing using call center architecture  2100  is described. When predictive dialing starts, CPD  2114  causes network switch  2110  to dial telephone numbers from its list. CPD  2114  can be a software comprising a list manager (for managing a list of phone numbers to be dialed) and a dialer application. CPD  2114  is connected to data communication network  2140 . When a connection to a potential buyer is established, network switch  2110  passes this information to CTI system  2112 , which routes the call to one of the agents in customer call center  2104 . Because telephone connections between provider call center  2102  and the agents have previously been established, network switch  2110  can immediately connect the call to the selected agent. As a result, there is little delay in establishing communication between the agent and the buyer.  
         [0116]    An important advantage of the present invention is that all call center features are centralized. As pointed out above, database server  2138  and stat-server  2134  contains information of the activities, users and agents of the call center. This information will be centrally available. Routing server  2136  can centrally control the operation of the entire system (which includes provider call center  2102  and all the customer call centers) and route calls to the most qualified agent to service a call.  
         [0117]    [0117]FIG. 11 is a flow chart  2200  showing the operation of the system shown in FIG. 10. In step  2204 , the agents in customer call center  2104  call the predetermined number to provider call center  2102 . In step  2206 , the call terminates at the means for continuously connecting an incoming call (such as loop around circuit  22120 ). At step  2210 , CPD  2114  dials phone numbers in a list. It determines whether a call is connected (step  2212 ). If the answer is negative (i.e., the call not connected), flow chart  2200  branches back to step  2210  and another phone number from the list is selected for dialing. If the answer is positive, the software in provider call center  2102  selects an appropriate agent to take the call. The call is routed to the selected agent (step  2216 ). CPD  2114  determines whether other phone numbers in the list need to be called (step  2220 ). If more numbers need to be called, flow chart  2250  branches back to step  2210 , and the phone numbers are dialed. If no more phone numbers in the list needs to be called, flow chart  2200  terminates (step  2222 ).  
         [0118]    It should be appreciated that the above described operation can be applied to other customer call centers. Also, other services, in addition to predictive dialing, can also be performed by network provider call center  2102 . For example, the present invention can also be used by provider call center  2102  to process all inbound calls of the customer call centers. In this situation, the delay in establishing communication between agents and callers may not be an overly important problem. However, the ability to centralized information and operation remain an important advantage of the present invention over the prior art.  
         [0119]    It should also be appreciated that even though CTI server  2132 , routing server  2136 , stat-server  2134  and database server  2138  are shown as separate components, they could be combined into one, two or three components residing on one or more data processing devices. In one embodiment of the present invention, they are implemented as a client/server architecture, and they can be geographically separated.  
         [0120]    In addition to customer call centers, individual stations can also use the service of the network call center. As an example, FIG. 10 shows a station  2180  having a telephone  2182  and a computer  2184 . Phone  2182  is connected to PSTN  2105  via line  2186  and computer  2184  is connected to data communication network  2140  via data connector  2188 . In operation, an agent in station  2180  dials a predetermined telephone number which terminates at network switch  2110 . Switch  2110  then connects this call to station trunk  2122 . As a result, telephone  2182  is connected to network switch  2110  until the agent terminates the call. Consequently, the equipment and software in provider call center  2102  are available to station  2180 .  
         [0121]    The present invention can also be applied to multiple network call centers. The data communication networks in these network call centers (such as network  2140  of FIG. 10) are connected to each other by a high speed data connector. The network switches of these call centers are connected to each other using reserved telephone connections. As a result, telephone calls can be routed from one call center to another without undue delay.  
         [0122]    System and Method for Operating a Plurality of Call Centers ( 3220 )  
         [0123]    The present invention comprises a novel call center architecture and related methods. The following description is presented to enable any person skilled in the art to make and use the invention. Description of specific applications is provided only as examples. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0124]    [0124]FIG. 12 shows a schematic diagram of a prior art system having call centers in separate geographic locations. As explained below, the operations of these call centers are not integrated, thereby leading to inefficient use of resources.  
         [0125]    [0125]FIG. 12 shows two call centers  3100  and  3150  out of a plurality of call centers. Because the structure of these call centers are similar, only one of them (center  3100 ) will be described in detail. Call center  3100  is connected to a public-switched telephone network (PSTN)  1304 . It comprises a switch  3108  for accepting calls from PSTN  3104 . Switch  3108  could be an automatic call distributor (ACD)/private branch exchange (PBX) or a PSTN switch. Switch  3108  contains a high bandwidth port  3110  (for connecting to PSTN  33104 ) and a plurality of low bandwidth ports (such as ports  3112 - 3114 ). Some of these low bandwidth ports can be connected to voice-based devices. For example, ports  3112 - 3113  is connected to telephones  3116 - 3117 , respectively. Agents are assigned to handle these telephones. Each of the low bandwidth ports is assigned one or more directory numbers (DN″).  
         [0126]    It has been found that the function performed by a standard switch is rather limited and cannot meet the requirements of a typical call center. For example, it is desirable to provide information about a call to a workstation (such as workstation  3132 - 3133 ) available to each agent. The telephone and a corresponding workstation form an integral unit (such as units  3141  and  3142 ) to serve a call. However, a switch cannot search, process and route data to these workstations. Consequently, a new technology, called computer-telephony-integration (CTI), is needed to route a combination of voice and digital data to desired places.  
         [0127]    As a way to implement CTI, call center  3100  further contains a routing subsystem  3122  connected to a CTI server  3124 , which is in turn connected to switch  3108  through a CTI link  3126 . The communication between switch  3108  and server  3124  typically follows the X.25 protocol. CTI server  3124  can be considered an interfacing software which allows routing subsystem  3122  to interact in a consistent manner with switch  3108  (which may be made by one of several vendors). Switch  3108  notifies CTI server  3124  when a call is received. CTI server  3124  sends the information to routing routine  3122 , which selects an agent best qualified to answer the call in accordance with predetermined criteria. CTI server  3124  then notifies switch  3108  to direct the call to the telephone of the selected agent while routing subsystem  3122  directs data relating to the person placing the call to the workstation of the selected agent.  
         [0128]    In order to facilitate data communication, a communication network  3136  is used to digitally connect routing subsystem  3122 , CTI server  3124  and workstation&#39;s  3132 - 3133 .  
         [0129]    As can be seen in FIG. 12, prior art call centers contain separate switch, CTI servers, and routing subsystems. The problem with this architecture is that routing can only be performed locally. Thus, even if there is an agent best suitable to handle a call, the call cannot be routed to this agent if he/she is located in another call center.  
         [0130]    [0130]FIG. 13 is a schematic diagram showing a global call center architecture  3160  in accordance with the present invention. This architecture allows routing of calls received by one call center to an agent located in a geographically separated call center. Digital data related to the calls (e.g., customer and ordering information related to telephones which originate the calls) is also routed to the agent. As a result, the resources of these call centers can be better utilized.  
         [0131]    As an example to illustrate the advantages of the global call center architecture, a call center may be temporarily swamped with calls, and thus need to direct calls to other call centers that are relatively quiet. The global call center architecture of the present invention can direct the calls to an appropriate agent in another call center, thereby fully utilizing the resources of the call centers.  
         [0132]    Another advantage of the present architecture is that it allows different call centers to maintain specialized resources. There are good reasons why specialized resources can be better acquired by different call centers. For example, call centers that are close to universities or high-tech areas would be in a better position to hire agents who can provide technical information to customers. Similarly, call centers located in metropolitan areas around the coastal areas would be in a better position to hire agents having foreign language skills. Thus, calls which require these specialized resources but initially received by a call center located away from the above-mentioned areas are likely to find the best qualified agent located in one of these call centers. The present inventions allow these calls to be routed to the best qualified agent in these specialized call centers.  
         [0133]    Yet another advantage of the architecture shown in FIG. 13 is that all the information can be centrally managed. As a result, the information in a database can be easily updated and maintained. In contrast, if each call center maintains its own database, it would be difficult to enforce data integrity.  
         [0134]    [0134]FIG. 13 shows two call centers  3162  and  3180  out of a plurality of call centers. The structure of only one call center (center  3162 ) is described in detail here because all the call centers have similar structure. Call center  3162  contains a switch  3168  that is similar to the switch  3108  of FIG. 12. Switching  3168  could be an automatic call distributor (ACD)/private branch exchange (PBX) or a PSTN switch. Switch  3168  contains a high bandwidth port (not shown) for connecting to a PSTN  3164  and a plurality of low bandwidth ports (not shown) for connecting to voice-based devices (such as telephones). Agents are assigned to handle these telephones. Each of the low bandwidth ports is assigned one or more directory numbers. Agents are also provided with workstations (not shown) for displaying callers (and other) information.  
         [0135]    Call center  3162  contains a CTI server  3170  that is connected to switch  3168  through a CTI-link  3172 . Up to this point, call center  3162  is similar to call center  3100  of FIG. 12. However, in the present architecture, the routing subsystem is not considered part of the call center.  
         [0136]    Similarly, call center  3180  contains a switch  3182  and a CTI server  3184  linked by a CTI-link  3186 . Switches  3168  and  3182  in call centers  3162  and  3180 , respectively, are connected by a tie line  3188 .  
         [0137]    It should be noted that switch  3168  and CTI server  3170  do not have to be located in the same physical area. The present invention does not impose any condition on the length of CTI link  3172 .  
         [0138]    Global call center  3160  contains a single stat-server  3190  to gather statistical information of all the call centers. It also contains a routing server  3192  for selecting appropriate agents using data in stat-server  3190  (and from other databases). Stat-server  3190  collects and stores historic data relating to all calls, activities of switches, and information and activities of all agents and telephones in all the call centers.  
         [0139]    One aspect of the present invention is a three-layer architecture in which a first layer comprises a plurality of switches and their matching CTI servers. The switches could be manufactured by different vendors. Each switch has a different capability and interface procedure. The matching CTI server is a routine which communicates and controls an associated switch one hand and, at the other hand, presents a common interface to the second and third layers. The second layer communicates with all the CTI servers in the first layer and all applications in the third layer. The third layer contains one or more applications which use the information contained in the second layer. In this embodiment, the second layer accumulates statistics on all aspects of the operation of the call centers, such as the agents and all activities of the automatic call distributors. The second layer provides this statistics to various applications in the third layer.  
         [0140]    In a preferred embodiment, various entities in a call center are associated with software objects. The following are some examples of these objects:  
         [0141]    (a) Queues and Routing Points: These are hardware circuits in switches and are represented as objects. Queue implements hardware controlled ACD mechanism. Routing points, sometimes called control directory number (CDN), can be controlled by external software applications (such as a routing routine).  
         [0142]    (b) Agent DNs: They are hardware ports in a switch and are represented as objects. Each DN is associated with one or more properties. For example, some DNs can access another DN directly; some DNs are associated with queues; some DNs are limited to outgoing calls; and some DNs have a period of unavailability after completion of a previous call. In a specific example, some of the switches manufactured by Northern Telecom contain basically two kinds of DNs, position and extension. Extension DNs can be accessed directly by a telephone and can initiate outgoing calls. Position DNs are associated with one or more queues. They can be accessed only through these queues and cannot initiate outgoing calls.  
         [0143]    (c) Agent Places: They are logical spaces each containing items associated with the space (e.g., one or more DNs, possibly attached to different switches, and workstations). In a physical implementation, these places could be desks. When an agent makes login to one item in a place, he (she) becomes logically logged in for the whole place. Each place is represented as an object and associated with a PlaceID.  
         [0144]    (d) Agents: Persons (objects) identified by an AgentID. Agents can move between places dynamically. The stat-server has a special routine for dynamically keeping track of the locations of all the agents. For example, an agent can work from 9:00 A.M. till 13:00 (i.e., 1:00 P.M.) at a first place; makes a logout (e.g., for lunch) and then makes a login at a second place at 14:00. The agent location tracking routine maintains the information so that the routing server (and other applications) knows which DN to dial to reach the agent. Each agent may also have a “home place,” which is a default value if the agent cannot be dynamically tracked.  
         [0145]    (e) Groups: A number of agents in any combination. Group objects are identified by GroupIDs. There are at least two types of groups. The first type (identified herein as SObjectGroupAgents) contains a list of AgentIDs. In this case, the stat-server tracks all agent movements and collect statistics only for included agents. Examples are groups with particular skills. The second type (identified herein as SObjectGroupPlaces) contains a list of agent places (PlaceIDs). Examples of places in the lists are training room, main office, second floor, etc. In this case, the stat-server tracks events related to places included in the list because it does not matter who works in these places.  
         [0146]    [0146]FIG. 14 is used to illustrate the above described objects. It shows two switch objects  3212  and  3213 , one represents switch  3168  and the other represents switch  3182 . Switch object  3212  comprises the following resources: CDN objects  3214  and  3215 , queueDN object  3216 , and DN objects  3217 - 3219 . These objects represent the corresponding CDN, queues, and agent DNs in switch  3168 . Similarly, switch object  3213  comprises the following resources: CDN object  3221 , queueDN object  3222 , and DN objects  3223 - 3224 . These objects represent the corresponding CDN, queues, and agent DNs in switch  3182 .  
         [0147]    The agent DN objects  3217 - 3219  and  3223 - 3224  are also included in agent place objects. In this example, agent place object  3226  includes DN objects  3217  and  3218 , agent place object  3227  includes DN objects  3219  and  3223 , and agent place object  3228  includes DN object  3224 . It should be noted that the DNs from two different switches can be associated with the same agent place.  
         [0148]    Some of the agent place objects can be grouped together to form place group objects. In FIG. 14, only one place group object  3232  is shown.  
         [0149]    [0149]FIG. 14 also shows a plurality of agent objects, such as objects  3230  and  3231 . In this example, agent object  3230  is dynamically linked to agent place object  3227  using the above mentioned agent location tracking routine, shown in FIG. 14 as a dashed line  3235 . Similarly, agent object  3231  is dynamically linked to agent place object  3228  using an agent location tracking layer, shown as a dashed line  3236 .  
         [0150]    Some of the agent objects can be grouped into agent group objects. In FIG. 14, only one agent group object  3233  is shown.  
         [0151]    Stat-server  3190  provides a set of application programming interfaces (APIs) for its clients to obtain statistics for various objects, such as objects associated with agents, agent groups, places, place groups, route points, queues, etc. Statistics could be current objects states representation (e.g., current agent status, current number of active calls in a group, etc.) or historical states representation. Historical representation are accumulated information for certain time intervals (e.g., total number of calls, total talk time, average talk time, etc.). Thus, the clients have to specify the time interval of interest. Examples of time intervals are:  
         [0152]    (a) SFixedStartSlidingEnd: The start time is fixed (e.g., 9:00 A.M.) while the end time is sliding (e.g., “till now”). For example, the client may request the total number of calls between 9:00 A.M. and now.  
         [0153]    (b) SFixedStartFixedEnd: Both the start and end times are fixed.  
         [0154]    (c) SFixedLengthSlidingEnd: The time interval is fixed while the start and end times are sliding. Example: the average call length for the past hour.  
         [0155]    Global call center  3160  also contains a routing server  3192  for selecting agents and places and causing the switches to route calls thereto. Routing server  3192  requests statistical information on objects of interest from stat-server  3190 . Routing server  3192  also has access to a separate database  3194  containing other relevant information, such as information relating to customers and agents in all the call centers in global call center  3160 . Using information from stat-server  3190  and database  3194 , routing server  3192  selects (using a software algorithm) the best agent for a specific call.  
         [0156]    As explained in FIG. 14, the statistics of many objects are tracked by stat-server  1390 . One of the reasons for creating these objects is that routing server  3192  typically requests information in the form of agents, agent groups, agent places and place groups. On the other hand, the CTI server sends to stat-server  3190  information about DNs and CDNs of their associated switches. These objects allow stat-server  3190  to easily communicate with various clients that can access it.  
         [0157]    The operation of global call center  3160  is now described using a flow chart  3260 . FIGS. 15A and 15B is used to illustrate the flow chart. In this example, it is assumed that a call is received by a CDN of switch  3168  (step  3262 ) of call center  3162  while the best suitable agent is located in call center  3180 . Instead of routing the call itself, switch  3168  notifies CTI-server  3170  of this event (step  3264 ). CTI server  3170  assigns a unique connection identification to this call (call herein as the first connection ID, for convenience), and pass this ID together with other information about this call, such as its “automatic number identification” (ANI) and (if applicable) “dial number identification system” (DNIS), to routing server  3192  (step  3266 ). The ANI uniquely identifies the telephone line which originates the call while the DNIS uniquely identifies the toll-free 800-number dialed by a telephone. CTI server  3170  also notify stat-server  3190  that a call has been received (step  3268 ) The connection ID, ANI, DNIS and other CTI-related parameters are also passed to the stat server  3190 .  
         [0158]    Routing server  3192  then sends API commands to database  3194  to request relevant information relating to this call (step  3270 ). For example, if a call originates from a telephone having a certain ANI, routing server  3192  asks database  3194  to retrieve information about persons related to this telephone. The details of a special API structure, called a “status priority table,” is described in detail in a separate patent application entitled “Method and System for Determining and Using Multiple Object States in a Computer Telephony Integration System.” This table allows an application to define the priority of various states of an object (e.g., the DN object). The stat-server  3190  can provide statistics to the requesting application in accordance with the predefined priority.  
         [0159]    Assuming that the retrieved information indicates that the mother tongue of the persons is French, routing server  3192  tries to look for an agent who knows French. Routing server  3192  then request statistics of all agents who know French from stat-server  3190  (step  3274 ). In step  3274 , routing server  3192  selects an agent based on this statistics using a predetermined criteria (e.g., how many calls have been handled by an agent, the length of time an agent has been waiting for calls, etc.).  
         [0160]    In this example, it is assumed that the selected agent is located in call center  3180 . Thus, routing server  3192  needs to (i) cause the call to be routed to an appropriate DN associated with the selected agent and (ii) route relevant customer information from database  3194  about this call to a workstation associated with the selected agent. The method for achieving the routing is described below.  
         [0161]    In step  3280 , routing server  3192  sends a command to CTI server  3184  in call center  3180  requesting reservation of a CDN in switch  3182 . This CDN will be used to accept a call from switch  3168 . CTI server  3184  assigns a second connection ID to this upcoming call. It then sends the CDN and second connection ID to routing server  3192  (step  3282 ).  
         [0162]    Upon receiving the information, routing server  3192  sends a command to CTI server  3170  of call center  3162  to cause switch  3168  to transfer the call to the specified CDN of switch  3182  of call center  3180  (step  3286 ). This command includes the first connection ID, thereby allowing CTI server  3170  to associate this command with the call of interest. Routing server  3192  also sends customer information (retrieved from database  3194 ) to a workstation associated with the selected agent (step  3288 ).  
         [0163]    Switch  3168  transfers the call to the specified CDN of switch  3182  via tie line  3188  (step  3290 ). Upon receiving the call, switch  3182  notifies CTI server  3184 . CTI server  3184  is able to determine that this call is associated with the second connection ID because it terminates at the specified CDN. It then causes switch  3182  to route the call to the DN associated with the selected agent (step  3292 ). CTI server  3184  may also optionally notify routing server  3192  that routing associated with the second connection ID is completed.  
         [0164]    As a result of the above described operations, routing server  3192  can route calls to agents located in all the call centers. Consequently, the resource of all the call centers can be fully utilized.  
         [0165]    Method for Routing Calls to Call Centers Based on Statistical Modeling of Call Behavior ( 3221 )  
         [0166]    [0166]FIG. 16 is a schematic diagram of a call center system  4100  of the present invention having a plurality of call centers (such as call center  4102   a ,  4102   b  and  4102   c ) and a central controller  4106 . Controller  4106  contains a call center interface unit  4108  for communicating with call centers  4102   a ,  4102   b  and  4102   c , a stat-server  4104  for containing statistical information of all the call centers, a database  4110  for storing agent and customer information, and a router  4114  for routing calls to individual call centers in accordance with a routing algorithm. These components are connected to each other via a data bus  4128 . Call center interface unit  4108  is connected to call centers  4102   a ,  4102   b  and  4102   c  using communication links  4118   a ,  4118   b  and  4118   c.    
         [0167]    When a caller dials a telephone number that is preassigned to call center system  4100 , the call (shown as line  4122  in FIG. 16) is temporarily parked at a network control point  4120  in the public switched telephone network (PSTN)  4124 . Network control point  4120  has the ability to route call  4122  to any one of the call centers  4102   a ,  4102   b  and  4102   c . Upon identifying that the called telephone number is controlled by central controller  4106 , network control point  4120  notifies central controller  4106  (through a network interface  4112 ) of the arrival of the incoming call via a communication link  4126 . Router  4114  of central controller  4106  determines the optimal routing of call  4122  using information in stat-server  4104  and database  4110 . The routing decision is sent to network control point  4120 . Call centers  4102   a ,  4102   b  and  4102   c  are connected to PSTN  4124  through telephone lines  4116   a ,  4116   b , and  4116   c , respectively. As a result, call  4122  is routed to the appropriate call center.  
         [0168]    It should be noted that the geographic location of central controller is not important for the present invention. Thus, central controller could be located inside or outside of PSTN  4124 . It could also be located inside the premise of one of the call centers.  
         [0169]    The structure of call centers  4102   a ,  4102   b  and  4102   c  are essentially the same. Consequently, only one of the call centers is described in detail here. FIG. 17 is a block diagram of such a call center  4130 . It contains an interface unit  4136  for communicating with central controller  4106 . It also contains a CTI server  4132  which is connected to an automatic call distributor (ACD)  4134 . It should be noted that a switch or private branch exchange (PBX) may be used. ACD  4134  could also be a switch. A number of agent stations (such as stations  4138   a  and  4138   b ) are located in call center  4130 . Each agent station typically contains a telephone (such as  4142   a  and  4142   b ) and a computer (such as computer  4144   a  and  4144   b ). The telephones are connected to ACD  4134  and the computers are connected to a data bus  4154 .  
         [0170]    After central controller  4106  determines that a call should be routed to call center  4130 , network control point  4120  forwards call  4122  to ACD  4134  (or a switch or PBX). If a switch is used, the call could be routed to a routing point in the switch wherein routing is controlled by external software. At the same time, central controller  4106  instructs CTI server  4132  to route call  4122  to a selected agent station (such as  4138   a ). Central controller  4106  may also supply customer information to computer  4144   a . Alternatively, call center  4130  may optionally contain a stat-server  4148 , a database  4152  and a router (not shown). In this case, routing inside call center  4130  is performed locally. CTI server  4132 , interface  4136 , stat-server  4148  and database  4152  communicate with each other through bus  4132 . Call center  4130  contains a number of hardware queues (e.g., ACD queues) and/or software queues maintained by the software in call center  4130 .  
         [0171]    Call center system  4100  will work optimally when central controller  4106  contains a complete set of information on all telephone traffic in system  4100 . However, it is possible that the communication link between one or more call centers and central controller  4106  be broken for a brief duration. In a conventional system, central controller  4106  will no longer route calls to these detached call centers. One aspect of the present invention is the realization that the telephone traffic behavior of a call center can be statistically estimated using historic data. As a result, it is possible for central controller  4106  to determine whether the detached call centers are busy. If it is determined that the detached call centers are not busy, central controller  4106  continues to instruct network control point  4120  to route calls to these detached call centers.  
         [0172]    One function of interface unit  4136  is to update central controller  4106  of the status of call center  4130 , such as the number of agents who have left the call center, the status of each agent, etc. This information is stored in stat-server  4104  of central controller  4106 . If communication link  4156  between call center  4130  and central controller  4106  becomes broken, central controller  4106  can use the status information to determine whether calls should be routed to call center  4130 . Even if the link is not broken, it is preferred to estimate the status, as explained below in connection with FIG. 18.  
         [0173]    [0173]FIG. 18 shows a time line  4202  running in a horizontal direction. At a time indicated by a line  4204 , a route request is generated because a new call has just arrived. A time interval indicated by a line  4206  is required to make a routing decision. The call is routed at a time indicated by a line  4208 . It takes a time interval  4210  for the call to be transmitted to a destination call center. At a time indicated by a line  4212 , the call arrives at the destination call center. The stat-server within the central controller needs a time interval (shown by a line  4214 ) to receive new statistical data because it takes time to pass information from the destination call center to the stat-server. At a time indicated by a line  4216 , the stat-server is updated. It can be seen from FIG. 18 that no actual data is available at the central controller for a time interval indicated by a line  4218 . The estimation algorithm of the present invention can be used to facilitate routing during this time interval.  
         [0174]    There are many ways to estimate telephone traffic in a call center. An exemplary algorithm for such purpose is described below. The symbols used in the algorithm are defined first.  
         [0175]    UT The time of the last update from the detached call center;  
         [0176]    A The total number of agents in the detached call center;  
         [0177]    AA The number of available agents in the detached call center;  
         [0178]    CQ The number of calls in the queue of the detached call center;  
         [0179]    AHT The average call handling time in the detached call center  
         [0180]    CA The number of answered calls in the detached call center;  
         [0181]    CC The number of completed calls in the detached call center;  
         [0182]    AC The number of agents on call in the detached call center;  
         [0183]    AW The number of agents in after-call work in the detached call center;  
         [0184]    AAW The number of agents in auxiliary work in the detached call center;  
         [0185]    OC The time of the oldest call in the queue of the detached call center;  
         [0186]    CADD A container for adding new calls;  
         [0187]    T The current time (i.e., time when a routing decision is made); and  
         [0188]    BA The number of busy agents in the detached call center.  
         [0189]    The algorithm is:  
         [0190]    ((T−UT)*min(CQ+AC+AW,A−AAW)/AHT&gt;CQ+AC+AW){BA=0; CC=CC+CQ+AC+AW; CQ=0;} 
         [0191]    else if (CQ+AC+AW−(T−UT)*min(CQ+AC+AW,A−AAW)/AHT &lt;A−AAW) {BA=CQ+AC+AW−(T−UT)*min(CQ+AC+AW,A−AAW)/AHT; CC=CC+(T−UT)*min(CQ+AC+AW,A−AAW)/AHT; CQ=0;} 
         [0192]    else {BA=A−AAW; CC=CC+(T−UT)*min(CQ+AC+AW,A−AAW)/AHT; CQ=max(O,CQ+AC+AW−(T−UT)*min(CQ+AC+AW,A−AAW)/AHT−A+AAW);} 
         [0193]    CA=CC+BA;  
         [0194]    AC=min(BA,max(0,BA*CD/AHT));  
         [0195]    AW=BA−AC;  
         [0196]    AA=A−AAW−BA;  
         [0197]    UT=T.  
         [0198]    In the above algorithm, the term (AC+AW) corresponds to the number of agents that are currently devoted to call-processing activity. The term CQ corresponds to the number of calls that are waiting to be processed because these calls are in the queue. Assuming that one agent handles one call at a time, this term (CQ+AC+AW) could be interpreted as (a) the number of agents needed to process calls already in the call center and (b) the number of calls that are currently being processed or need to be processed. The term (A−AAW) corresponds to the number of agents that are not in auxiliary work, and are thus presumably devoted to call processing activities. The term (T−UT) is the time interval from the last update time to the current time. Consequently, (T−UT)/AHT corresponds to the number of calls that can be handled by each agent in the call center during this time period. Thus, the term (T−UT)*min(CQ+AC+AW,A−AAW)/AHT corresponds to probable number of calls being processed or need to be processed. As a result, the term under the “if” clause corresponds to the case where all incoming calls have been processed in time interval (T−UT). That is, the load is very light relative to the capability of this call center. Consequently, the number of busy agents and the number of calls in the queue are equal to zero.  
         [0199]    The term under the “else if” clause is invoked when not all calls have been processed. However, the approximate number of unprocessed calls is less than the number of available agents. If this condition occurs, some of the agents are currently answering calls. However, there is no unanswered calls that need to be placed in the queue because there are agents available to answer the call.  
         [0200]    When neither the conditions in the “if” or the “else if” clause are met, some calls will be placed in the queue because all available agents are busy in answering calls.  
         [0201]    Using the above statistical model, central controller  106  can determine the capability of the detached call center to process new calls. Other information may also be needed in determining where to route a call. One piece of information is the time when the oldest call in the queue arrive (“OC”). For example, a routing strategy may not route calls to a call center where the calls in its queue has a long OC. This parameter can be estimated statistically. As an example, central controller  106  may contains a plurality of containers (“CADD”), one for each call center, for recording the time of arrival of all calls processed or to be processed by the call centers. The CADD is an internal queue, created and updated by central controller  4106  for use by this statistical modeling. One way to determine OC is to trace back from the newest call in the CADD a number of calls equal to CQ (i.e., the number of calls in the queue). Because CQ can be determined from the above statistical model, OC can also be determined from this statistical model.  
         [0202]    Based on the above algorithm, it is possible to predict how many calls a call center can accept. Consequently, central controller  4106  may route calls to a call center even when no instantaneous data related to the call center is available.  
         [0203]    The above statistical model can be used in the case where status data of each call centers can only be sent to central controller  4106  at pre-assigned times. In this case, this statistical model is used to estimate call behavior between the times status data is sent.  
         [0204]    Method and Apparatus for Determining and Using Multiple Object States in a Computer Telephony Integration System ( 3222 )  
         [0205]    The present invention comprises novel call center method and system. The following description is presented to enable any person skilled in the art to make and use the invention. Description of specific applications is provided only as examples. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0206]    [0206]FIG. 19 is a block diagram of a call center  5100  which can be used to implement the present invention. Call center  5100  is connected to a public-switched telephone network (PSTN)  5104 . It comprises a switch  5108  for accepting calls from PSTN  5104 . Switch  5108  could be an automatic call distributor (ACD)/private branch exchange (PBX) or a PSTN switch. Switch  5108  contains a high bandwidth port  5110  (for connecting to PSTN  5104 ) and a plurality of low bandwidth ports (such as ports  5112 - 5116 ). Some of these low bandwidth ports can be connected to voice-based devices. For example, ports  5112 - 5115  are connected to telephones  5120 - 5123 , respectively. Agents are assigned to handle these telephones. Each of the low bandwidth ports is assigned one or more directory numbers (“DNs”).  
         [0207]    It has been found that the function performed by a standard switch is rather limited and cannot meet the requirements of a typical call center. For example, it is desirable to provide information about a call to a workstation (such as workstation  5126 - 5127 ) available to each agent. However, a switch cannot search, process and route data to these workstations. Consequently, a new technology, called computer-telephony-integration (CTI), is needed to route a combination of voice and digital data to desired places.  
         [0208]    As a way to implement CTI, call center  5100  further contains a routing subsystem  5130  connected to a CTI server  5132 , which is in turn connected to switch  5108  through a CTI link  5134 . The communication between switch  5108  and CTI server  5132  typically follows the X. 25  protocol. CTI server  5132  provides an interface between routing subsystem  5130  and switch  5108 . Switch  5108  notifies CTI server  5132  when a call is received. CTI server  5132  sends the information to routing subsystem  5130 , which selects an agent best qualified to answer the call in accordance with predetermined criteria. CTI server  5132  then notifies switch  5108  to direct the call to the telephone (i.e., DN) of the selected agent while routing subsystem  5130  directs data relating to the person placing the call to the workstation of the selected agent.  
         [0209]    In one embodiment of the present invention, routing subsystem  5130  contains a stat-server  5140 , a routing server  5142 , and a database  5144 . They communicate with one another using a data communication network  5150 . Stat-server  5140  collects and stores historic data relating to all calls, activities of switches, and information and activities of all agents in call center  5100 . Database  5144  contains information of customers, agents, telephone numbers, and various aspects of call center  5100 . Routing server  5142  selects appropriate agents to handle calls using data in stat-server  5140  and database  5144 . After the selection, routing server  5142  sends a command to CTI server  5132 , which in turn instructs switch  1508  to route incoming calls to the selected agents.  
         [0210]    There may be other CTI-related applications (i.e., software modules) which uses the resource of database  5144  and stat-server  5140  so as to provide other services or information to the agents in the call center. In FIG. 19, two applications ( 5152  and  5153 ) are shown. Examples of applications are “Agent View” and “Call Center View” marketed by Genesys Telecommunications Laboratories. These applications are connected to data communication network  5150 .  
         [0211]    In a call center, it is common for an agent to manage more than one telephone. The equipments used by an agent is usually set up in a convenient place (such as a desk), called “agent place” in the present application. FIG. 19 shows two exemplary agent places  5161  and  5162 . Agent place  5161  contains a workstation  5126  and two telephones  5120  and  5121 . Similarly, agent place  5162  contains a workstation  5127  and two telephones  5126  and  5127 . When an agent occupies an agent place, he/she logs on using either a telephone or a workstation therein. Before the agent leaves the agent place, he/she logs out using the telephone or workstation. Consequently, call center  5100  is able to keep track of the current location of each agent.  
         [0212]    Stat-server  5140  communicates with CTI server  5132 , routing server  5142  and applications  5152 - 5153  via a set of application programming interface (“API”) commands. Stat-server  5140  (working with CTI server  5132 ) can monitor and store activities of switch  5108 . It also monitors and stores activities of various agents and agent places. In response to inquiry by routing server  5142  and applications  5152 - 5153  regarding the status of an object of interest (e.g., an agent), stat-server  5140  provides a report to routing server  5142 . In an embodiment where one stat-server is used to manage several switches (which may be located in one or more call centers), stat-server  5140  monitors and stores activities of all the switches, all the agents and all the agent places served by these switches. A detailed description of a multiple call center architecture which may use the stat-server of the present invention is disclosed in a copending patent application entitled “System and Method for Operating a Plurality of Call Centers” filed January  13 ,  1997  and assigned to the same assignee of the present application. This patent application is incorporated herein by reference.  
         [0213]    It is observed that most call center entities (e.g., telephones and agents) could simultaneously have multiple states. For example, an agent telephone is designed to handle several activities at the same time. Thus, the agent may use the same telephone to talk to one customer, put another person (e.g., a co-worker) on hold, and waiting for an incoming call. Under prior art systems, this presents a reporting problem when the stat-server reports the state of the telephone to other CTI applications because it is not clear which state (out of several states) should be reported.  
         [0214]    The present invention is a method and system which take advantage of the multiple states. It realizes that different CTI applications need to use state-related information differently. For example, a regular routing routine would consider an agent busy if he/she is talking on a telephone or using a workstation to enter data. However, an application which handles high priority calls (e.g., emergency calls or calls from valued customers) would consider the same agent available as long as he/she is logged on to the agent place. This is because the agent can stop working with the workstation or place a call on hold if there is an emergency phone call. Thus, the present invention allows an application to define which of the several states they wish to be informed.  
         [0215]    An embodiment of the present invention is now described. In this embodiment, various entities in a call center are associated with software objects. The following are some examples of these objects:  
         [0216]    (a) Queues and Routing Points: These are hardware circuits in switches and are represented as objects. Queue implements hardware controlled ACD mechanism. Routing point, sometimes called control directory number (“CDN”), can be controlled by software applications (such as a routing routine).  
         [0217]    (b) Agent DNs: They are hardware ports in a switch and are represented as objects. Each DN is associated with one or more properties. For example, some DNs can access another DN directly; some DNs are associated with queues; some DNs are limited to outgoing calls; and some DNs have a period of unavailability after completion of a previous call. In a specific example, some of the switches manufactured by Northern Telecom contain basically two kinds of DNs, position and extension. Extension DNs can be accessed directly by a telephone and can initiate outgoing calls. Position DNs are associated with one or more queues. They can be accessed only through these queues and cannot initiate outgoing calls.  
         [0218]    (c) Other specific DNs: They are DNs connected to specific devices, such as voice mail systems, interactive voice response units, etc. These DNs are represented as objects.  
         [0219]    (d) Agent Places: They are logical spaces each containing items associated with the space (e.g., one or more DNs, possibly attached to different switches, and workstations). In a physical implementation, these places could be desks. When an agent makes login to one item in a place, he (she) becomes logically logged in for the whole place. Each place is represented as an object and associated with a PlaceID.  
         [0220]    (e) Agents: Persons (objects) identified by an AgentID. Agents can move between places dynamically. The stat-server has a special routine for dynamically keeping track of the locations of all the agents. For example. an agent can work from 9:00 AM till 13:00 (i.e., 1:00 PM) at a first place; makes a logout (e.g., for lunch) and then makes a login at a second place at 14:00. The agent location tracking routine maintains the information so that the routing server (and other applications) knows which DN to dial to reach the agent. Each agent may also have a “home place,” which is a default value if the agent cannot be dynamically tracked.  
         [0221]    (f) Groups: A number of agents in any combination. Group objects are identified by GroupIDs. There are at least two types of groups. The first type (identified herein as SObjectGroupAgents) contains a list of AgentIDs. In this case, the stat-server tracks all agent movements and collect statistics only for included agents. Examples are groups with particular skills. The second type (identified herein as SObjectGroupPlaces) contains a list of agent places (PlacelDs). Examples of places in the lists are training room, main office, second floor, etc. In this case, the stat-server tracks events related to places included in the list because it does not matter who works in these places.  
         [0222]    [0222]FIG. 20 is used to illustrate the above described objects. It shows two switch objects  5212  and  5213  simulating two physical switches in one or more call centers. Switch object 5   212  comprises the following resources: CDN objects  5214  and  5215 , queueDN object  5216 , and DN objects  5217 - 5219 . Similarly, switch object  5213  comprises the following resources: CDN object  5221 , queueDN object  5222 , and DN objects  5223 - 5224 . These objects represent the corresponding CDN, queues, and agent DNs in the physical switches.  
         [0223]    The agent DN objects  5217 - 5219  and  5223 - 5224  are also included in agent place objects. In this example, agent place object  5226  includes DN objects  5217  and  5218 , agent place object  5227  includes DN objects  5219  and  5223 , and agent place object  5228  includes DN object  5224 . It should be noted that the DNs from two different switches can be associated with the same agent place.  
         [0224]    Some of the agent place objects can be grouped together to form place group objects. In FIG. 20, only one place group object  5232  is shown.  
         [0225]    [0225]FIG. 20 also shows a plurality of agent objects, such as objects  5230  and  5231 . In this example, agent object  5230  is dynamically link to agent place object  5227  using the above mentioned agent location tracking routine, shown in FIG. 20 as a dashed line  5235 . Similarly, agent object  5231  is dynamically link to agent place object  5228  using the above described dynamical tracking routine (shown as a dashed line  5236  in FIG. 20).  
         [0226]    Some of the agent objects can be grouped into agent group objects. In FIG. 20, only one agent group object  533  is shown.  
         [0227]    Stat-server  5190  provides a set of APIs for its clients to obtain statistics for various objects, such as objects associated with agents, agent groups, agent places, place groups, route points, queues, etc. Statistics could be current objects states representation (e.g., current agent status, current number of active calls in a group, etc.) or historical states representation. Historical representation are accumulated information for certain time intervals (e.g., total number of calls, total talk time, average talk time, etc.). Thus, the clients have to specify the time interval of interest. Examples of time intervals are:  
         [0228]    (a) SGrowingWindow: The start time is fixed (e.g., 9:00 AM) while the end time is sliding (e.g., “till now”). For example, the client may request the total number of calls between 9:00 AM and now.  
         [0229]    (b) SSlidingWindow: The time interval is fixed while the start and end times are sliding. Example: the average call length for the past hour.  
         [0230]    Returning now to the description of objects, each object has one or more states. In one embodiment of the present invention, agent DN objects may have the states shown in Table 1. It should be noted that the number and nature of states are implementation details, and thus, can easily be changed by persons skilled in the art.  
                       TABLE 1                           (1)   NotMonitored:   The CTI server is not currently               tracking the status of this agent               DN. Consequently, the stat-server               is not accumulating statistical               information for this DN.       (2)   Monitored:   The agent DN is monitored by the               CTI server.       (3)   LoggedIn:   It indicates that an agent has               logged in to the agent DN.       (4)   OnHook:   It indicates that an agent DN is on               hook and is waiting for a call.       (5)   WaitForNextCall:   This is active at almost               all time, even when this agent               DN has active calls or when there               is no agent (for the possibility of               leaving a voice mail message). The               only situation in which               WaitForNextCall is not active is               when a predetermined key is press-               ed (see NotReadyForNextCall               below).       (6)   OffHook:   It indicates that the telephone               receiver is offhook. However,               other states can be active when               the receiver is offhook (e.g.,               WaitForNextCall).       (7)   CallDialing:   It indicates that an agent has               dialed a call but that the call               is not yet established.       (8)   CallRinging:   It relates to an action occurr-               ing on an agent DN from the mo-               ment an inbound call begins ring-               ing to the time just before the               handling of the call by an agent.       (9)   NotReadyForNextCall:   This refers to a hardware condition               preventing the receipt of calls.               It is usually activated by press-               ing a predetermined key.       (10)   OfflineWorkType1:   It indicates that an agent is offline               to do work that can be classified               as type 1.       (11)   OfflineWorkType2:   It indicates that an agent is offline               to do work that can be classified               as type 2.       (12)   CallOnHoldUnknown:   It indicates that a call of unknown               type is on hold.       (13)   CallOnHoldConsult:   It indicates that a consulting call               is on hold.       (14)   CallOnHoldInternal:   It indicates that an internal call               is on hold       (15)   CallOnHoldOutbound:   It indicates that an outbound call               is on hold       (16)   CallOnHoldInbound:   It indicates that an inbound call is               on hold       (17)   CallUnknown:   It indicates that the CTI server               cannot determine whether the call               is a consult, internal, outbound,               inbound or on-hold call.       (18)   CallConsult:   It indicates that a consulting call               is in progress.       (19)   CallInternal:   It indicates that call between two               extensions (internal calls) is in pro-               gress (i.e., when no prefix is used)       (20)   CallOutbound:   It indicates that an outbound call is               in progress.       (21)   CallInbound:   It indicates that an inbound call is               in progress.       (22)   LoggedOut:   It indicates that an agent has               logged out from the agent DN.       (23)   CallDialed:   It indicates that a successful result               was achieved when a call was               dialed.       (24)   CallAbandonedFromDialing:   It indicates that during the               process of a call dialing (and               before another party answers),               the agent hung up the phone.       (25)   CallAnswered:   It indicates that a call was               answered.       (26)   CallAbandonedFromRinging:   It indicates that another party               hung up the phone while a call               was ringing.       (27)   CallAbandonedFromHolding:   It indicates that another party               hung up the phone while a call               was on hold.                  
 
         [0231]    The above listed states correspond to actions that can be “executed” by an agent DN. As mentioned above, an agent DN could be in a plurality of these states at the same time (called herein the “active states”). In one embodiment of the present invention, the stat-server of the present invention reports to its clients an agent DN status that is equal to the active state having the highest priority. In the present invention, the priority is set by the clients of the stat-server. This is accomplished by the client sending a status priority table (“SPT”) to the stat-server as part of the parameters in requesting information on the status of an agent DN. This table contains the same states shown in the listing of Table  1  such that these states are arranged in a priority order defined by that client. In reporting to the client, the stat-server reports a status corresponding to the active state of the agent DN having the highest priority as defined in the received SPT. It should be noted that the reported status could be the active state that corresponds to other priorities on the SPT. If the client requesting the information does not provide a SPT, a default SPT is used. Further, the client may provide a different SPT at separate requests for information.  
         [0232]    One advantage of this aspect of the present invention is that each client can obtain information it deems to be the most pertinent. In the prior art system, the stat-server reports only one status for an agent DN to all the clients that request the information. In the present invention, the stat-server can report different status for the same agent DN to different clients, depending on the SPT parameters sent by the clients. Because each client receives the information it wants, the resource of the call center can be better utilized.  
         [0233]    As pointed out above, each agent may has access to two or more telephones (i.e., agent DNs). In this case, the client may define an agent SPT indicating the priority of the actions in both agent DNs.  
         [0234]    As an example, it is assumed that an agent has access to two agent DNs: the first DN has a state of “OfflineWorkType1” and the second DN has a state of “WaitForNextCall.” The status of the agent reported to the client is “OfflineWorkType1” if it has a higher priority. As another example, a client (e.g., routing server  5142 ) of the stat-server may consider the status of an agent to be “WaitForNextCall” when all the agent DNs associated with the agent have the “WaitForNextCall” state. This corresponds to the case when the agent is not actively performing any call center related activity (e.g., answering a call or using the workstation), and as a result, all the agent DNs are not being used and are waiting for a call. This priority arrangement is achieved by putting “WaitForNextCall” as the action having the lowest priority in an agent SPT. However, if there is a special or urgent call, routing server  142  may want to consider the status of the agent to be “WaitForNextCall” when there is at least one agent DN associated with the agent having the “WaitForNextCall” status. This corresponds to the case when the agent has access to at least one phone that is not being used. This priority setting is achieved by putting “WaitForNextCall” as the highest priority in the agent SPT.  
         [0235]    In one embodiment of an agent SPT, the priority of the states are listed sequentially and separated by a comma, with the lowest priority listed first. The agent SPT with a lowest priority for “WaitForNextCall” would be: “WaitForNextCall, . . . (other states).” On the other hand, the agent SPT with a very high priority for “WaitForNextCall” would be “ . . . , WaitForNextCall, LoggedOut”. In this case, the highest priority is “LoggedOut” and the priority just below it is “WaitForNextCall”.  
         [0236]    Agents can be arranged in groups. Group status is based on all included agent statuses. It is determined by a “Group SPT,” which is similar to the Agent SPT and DN SPT. As an example, a Group SPT of “ . . . , WaitForNextCall” means that the group will be in “WaitForNextCall” if there is at least one “WaitForNextCall” agent status.  
         [0237]    Routing points and queues can also report different status to different clients in respond to different SPTs. The states of an exemplary routing point/queue are shown in table 2.  
                       TABLE 2                           (1)   NotMonitored:   The CTI server is not currently tracking               the status of this DN. Consequently, the               stat-server is not accumulating stat-               istical information for this DN       (2)   Monitored:   The routing point/queue is monitored by               the CTI server.       (3)   NotReadyForNextCall:   This state occurs when a PBX source               used for routing or a queue DN has               reached capacity. Note that this capacity               is very large and is not normally               reached.       (4)   CallWait   Call is holding on a routing point/queue       (5)   CallEntered   This is an “instant” action indicating               that a new call has just entered a routing               point or queue.       (6)   CallDisturbed   It indicates that a call previously in a               routing point/queue has just been               agent.       (7)   CallAbanadoned   This indicates that a customer just hung               up while the call is at a routing point or               in a queue.       (8)   WaitForNextCall:   This indicates that a routing point/queue               still has a capacity to handle more calls.                  
 
         [0238]    In one embodiment of the present invention, there are two main calls that allow clients to obtain statistics from the stat-server. The first call is “SGetStat.” This call requests the stat-server to return statistics of interest only once. The second call is “SOpenStat.” It means that the client is interested in receiving statistics on a continuous basis. The client can further set up various criteria for the stat-server to notify the client and report statistics. For example, the client can specify that notification takes place only when the new value is greater than the last reported value by a predefined percentage. Alternatively, the client can specify that notification takes place at predefined time intervals.  
         [0239]    One of the parameters of the SGetStat and SOpenStat calls relates to the SPT. In one embodiment of the present embodiment, the parameters for each of these calls contain a pointer to a data structure having a number of optional fields. The SPT for agent DN, agent, group, and routing point/queue each occupies one of these optional fields. Thus, an application can define the appropriate SPTs and incorporate them in the data structure. This data structure is used to invoke the SGetStat and SOpenStat calls.  
         [0240]    In an embodiment in which multiple switches are monitored by the same stat-server, the above mentioned calls also contain a parameter allowing the client to indicate the switch of interest.  
         [0241]    System for Routing Electronic Mails ( 3223 )  
         [0242]    The present invention comprises a novel routing system for electronic mails and related methods. The following description is presented to enable any person skilled in the art to make and use the invention. Decryption of specific applications is provided only as examples. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other em bodiments and applications without departing from the spirit and cope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0243]    [0243]FIG. 21 is a block diagram showing an e-mail processing center  6100  of the present invention. Processing center  6100  contains an e-mail server  6102  which is connected to a data network  6104 . Data network  6104  could be a local area network or a wide-area network (such as the Internet or an Intranet). Other data processing devices, such as computers  6106  and  6108 , are also connected to data network  6104 . All the data processing devices can send e-mails to each other. As a result, some of the e-mails are sent to e-mail server  6102 .  
         [0244]    As an example, it is assumed that one of the addresses associated with e-mail server  6102  is “support@abc-company.com”. This is an address for customers of a company named “ABC” to send in questions regarding products and services provided by the company. It is anticipated that the subject matters of the e-mails are diverse and the number of mails is large. For example, the e-mails may relate to all aspects of the products and services offered by ABC. Some of the e-mails may contain technical questions of a product. Other e-mails may report a bug in a software sold by ABC. A few e-mails may contain suggestions on improving the products and services. If support persons of ABC are assigned to answer some of the e-mails on a first come first serve basis, it would be very difficult for them to do so because it is almost impossible for a single person to know everything about ABC.  
         [0245]    One aspect of the present invention is a system for automatically routing the e-mails to the most qualified and available support person. For example, a support person may be an expert in one product of ABC. All e-mails related to this product will be routed to this person automatically. Further, the system can distribute the load so that every support person receives approximately the same number of e-mails. As a result, the problems of the prior art systems can be solved.  
         [0246]    Note that the criteria for determining whether a support person is available is not limited to e-mail activities. This is because the same support person may provide telephone and facsimile support to customer inquiries. Thus, the “availability” of a support person may involve a combination of activities involving telephone, facsimile, e-mail, data processing, etc.  
         [0247]    Processing center  6100  contains a server  6112  that records all activity in the center. For example, it contains records of who are present in the center a a particular time and are available for service, as well as records of all e-mails that are pending and have been processed by center  6100 . Server  6112  is called herein as the “stat-server.” It should be noted that many types of information can be reorder, and the choice of information is determined on a case-by-case basis.  
         [0248]    Processing center  6100  also contains a database  6114  that contains detailed information on each support person, products and customers. Information of support persons includes the skill set (e.g., product expertise, written language ability) and prior relationship with customers. Information of customers (bases on the incoming e-mail address) includes the content of their previous e-mails, the products they bought, their physical addresses (obtained from product registration information ), etc.  
         [0249]    Processing center  6100  also contain s a router  6116 . This router selects the most qualified and available support person to respond to a particular e-based on one or more algorithms (or scripts). Various factors in a routing strategy will be described below.  
         [0250]    In one embodiment of the present invention, database  6114 , router  6116  and stat-server  6112  could be a database, router and stat-server commonly used in telephony call centers. The advantage of this embodiment is that database, router and stat-server software for telephony applications are well developed and widely available. The use of existing software (or slightly modified versions)could speed up product development time. In telephony applications, a server is used to provide computer telephony integration (CTI) by controlling an automatic call distributor (a telephony hardware device for controlling telephone communication between the public telephone networks and telephones inside a call center) and communicating with a database, router and stat-server. This server is call herein the CTI-server. One of the functions of the CTI server is allowing automatic call distributors of different vendors to be used with the same database, router and stat-server.  
         [0251]    In this embodiment, a CTI-server  6130  and an e-mail-to-CTI-server adapter  6110  is preferably included. As explained above, CTI-server  6130  provides a common interface for communicating with database  6114 , router  6116  and stat-server  6112  via a digital communication network  6128 . Because these software products are based on telephony applications, some of the attributes used therein may not be exactly the same as that used in e-mail applications. For example, the attribute of “telephone number” in telephony application is not used in e-mail applications. Similarly, the e-mail attribute of “sender&#39;s e-mail address” may not be recognizable in telephony applications. These two attributes have similar characteristics, and can be used interchangeably provided that they are formatted and used properly. One of the functions of adapter  6110  is to provide conversion between e-mail attributes and telephony attributes.  
         [0252]    [0252]FIG. 22 is a block diagram of e-mail-to-CTI-server adapter  6110 . It includes an e-mail interface  6202  for sending data to and receiving data from e-mail server  6102 . Adapter  6110  also includes an information extractor  6204  for extracting relevant information from e-mails. Extractor  6204  contains a parser  6206  for parsing the content of the e-mails obtained from e-mail server  6102 . Extractor  6204  also contains a storage device for storing an algorithm  6208  which directs parser  6206  to extract appropriate information from the content of the e-mails in accordance with predetermined criteria. The extraction algorithm in extractor  6204  is changeable because the coding in algorithm  6208  could be changed. Examples of relevant information are:  
         [0253]    (a) Addresses: Typically, an e-mail has a portion that contains the addresses of the sender and recipient. Extractor  6204  directs parser  6206  to extract these e-mail addresses.  
         [0254]    (b) Time Stamp: Some e-mail contains the date and time an e-mail is sent.  
         [0255]    Extractor  6204  could direct parser  6206  to extract this information. This information may be more accurate that the time e-mail server  6102  receives the e-mail because some e-mails may be delayed for more than a day due to network problems.  
         [0256]    (c) Keyword: Extractor may direct parser to conduct a keyword search on the content of the e-mails. Example of keywords are name of relevant products and services provided by the company, special words such as “bugs”, “virus”, “crash” (for software products), “overheat” and “electric shock” (for hardware products), and words of urgent nature (such as “urgent”, “ASAP”, and “fast”).  
         [0257]    Adapter  6110  contains a formatter  6210  for formatting the relevant information into attributes that can be understood by CTI-server  6130 . As an example, the sender&#39;s e-mail address could be formatted as a caller&#39;s telephone number (which is a telephony attribute). The formatted attribute is sent to a data communication interface  6212  which communicates the attributes to CTI server  6130  via communication network  6128 .  
         [0258]    Adapter  6110  also contains a deformatter  6214  that accepts data and commands from CTI-server  6130  and translate them to a form understood by e-mail server  6102 . As explained below, router  6116  may send (via CTI-server  6130 ) commands to e-mail server  6102 .  
         [0259]    Returning now to router  6116 , some examples of support person selection criteria are:  
         [0260]    (a) the product expertise of the support person;  
         [0261]    (b) language ability of the support person;  
         [0262]    (c) activities the support person (e.g. ,how many e-mails have this person processed and how many are pending);  
         [0263]    (d) work load of other support persons in the center (for load balance among various support persons);  
         [0264]    (e) the language of the incoming e-mail;  
         [0265]    (f) the subject matter of the incoming e-mail;  
         [0266]    (g) information about the sender;  
         [0267]    (h) overall activities of the center (e.g. whether the support persons need to process jobs other than e-mails); and  
         [0268]    (i) the urgency of the matter.  
         [0269]    Processing center  6100  contains a number of computer terminals, such as computers  6122  and  6124 , managed by support persons. When a support person starts to work, he/she logs in so that stat-server  6112  knows who is working in center  6100  and how to reach the support person.  
         [0270]    Router  6116  obtains information to make selection decision from stat-server  6112  and database  6114 . Once a decision is made, router  6116  sends a command to e-mail server  6102  to route the e-mail to the selected computer terminal. The support person responds to the e-mail and sends the reply to e-mail server  6102 , which delivers the reply to the sender via data network  6104 .  
         [0271]    A flow chart  6150  showing the operation of e-mail processing enter  6100  is shown in FIG. 23. In step  6152 , e-mail server  6102  receives an e-mail. The e-mail is forwarded to e-mail-to-CTI-server adapter  6110 . In step  6154 , adapter  6110  extracts e-mail attributes in accordance with pre-configured rules (embodied in extraction algorithm  6208 ). It also sends status information and formulates requests to CTI-server  6130  using appropriate extracted attributes. In step  6156 , CTI-server  6130  forwards the request and status information to router  6116  and stat-server  6112 . In step  6158 , router  6116  retrieves information from stat-server  6112  and database  6114  so as to make routing decision. In step  6160 , router  6116  instructs e-mail server  6102  to route the e-mail to the computer terminal used by a selected support person, such as computer  6122 . Because the instructions from router  6116  may be coded in telephony-related commands, these instructions may need t pass through CTI-router  6130 , deformatter  6210  and e-mail interface  6202 . Upon receiving the e-mail, the support person processes the e-mail using computer  6122 . If there is a need to send a reply, the support person writes the reply (step  6162 ), and directs e-mail server  6102  to deliver the reply to a recipient connected to data network  6104  (step  6164 ).  
         [0272]    In addition to providing basic routing function, router  6116  may also have a strategy to handle exception situations. For example, if an incoming mail is not answered by the selected support person within a predetermined time interval (e.g., three days), the mail is re-routed to another qualified and available support person. This strategy prevents mails from being dropped. As another example, there may be times when the number of incoming mails exceeds the available resource to answer these mails (i.e., overflow). Router  6116  could store these mails in a queue and direct e-mail server  6102  to alert senders that it may take a little longer to receive a reply.  
         [0273]    It should be noted that if router  6116 , stat-server  6112  and database  6114  are designed strictly for e-mail applications, there is not need to have CTI server  6140 , formatter  6210  and deformatter  6214 . In this case router  6116 , stat-server  6112  and database  6114  can communicate with e-mail server  6102  and information extractor  6204  directly.  
         [0274]    Internet Protocol Network Telephony (IPNT)  
         [0275]    In all of the embodiments and aspects of the invention described above specific example have been drawn principally from the technological area of conventional intelligent telephony networks, other than what is now known as Internet protocol network telephony (IPNT), wherein computers simulate telephones through software, microphones, and speakers, and telephony data between such equipped computers is transmitted over Internet (and sometimes other data networks, such as Intranets) connections and directed by servers, such as destination number servers (DNS) in the Internet. In the IPNT world IP addresses are used instead of telephone numbers, and there are differences in the way data packets are formulated and transmitted. Moreover, what may be termed routing is done by such as IP switches and hubs, wherein destination addresses may be changed. These differences, however, are not limiting in embodiments of the present invention.  
         [0276]    In many embodiments of the invention described, the inventions are involved with new and unique ways to use machine intelligence for telephony functions, particularly, but not exclusively, as these functions relate to call centers and intelligent routing of calls. In instances of the invention described, as will be readily apparent to those with skill in the art, the principles of the invention may also be applied to IPNT without undue experimentation.  
         [0277]    As examples of IPNT application, in those embodiments dealing with personal routing and personal routers, the methods and apparatus described may also be adapted to IPNT so personal routing rules, negotiation, and the like may be provided for IPNT calls as well. In the aspects of the invention dealing with simulation of CTI applications and testing, the applications may apply to IPNT telephony as well as to more conventional telephony systems. Other examples will be apparent to those with skill in the telephony arts.  
         [0278]    It will be apparent to those with skill in the art that there are many alterations that may be made in the embodiments of the invention herein described without departing from the spirit and scope of the invention. Some of these have been described above Many of the functional units of the system in embodiments of the invention may be implemented as code routines in computerized telephony equipment, computer servers, and individual workstations. It is well-known that programmers are highly individualistic, and may implement similar functionality by considerably different routines. Also, the invention may be applied to widely varying hardware systems. Further, hardware used to practice the invention may vary in many ways. There are similarly many other alterations in the embodiments described herein which will fall within the spirit and scope of the present invention in it&#39;s several aspects described. The invention is limited only by the breadth of the claims below.