Abstract:
A networking system includes telephone switches and data network gateways for routing calls either over the public telephone network or over the packet switched data network. A router examines initiated calls and selects either the telephone network or a data network for completing the call. A Network Operations Center (NOC) monitors the performance of plural gateways, and updates routing information in the router and/or in the gateways, which may be used for future calls.

Description:
FIELD OF THE INVENTION 
   The present invention relates to telephony. More particularly, in some embodiments, the present invention relates to a system and method for monitoring, evaluating and actively managing telephone-call quality in data-network-based telephony networks. The present invention also relates to a technique of selecting from among at least a telephone network and a packet switched data network in order to convey a call to a remote location. 
   BACKGROUND OF THE INVENTION 
   Data networks such as the Internet are now being used to transmit voice. Such data-network-based telephony networks provide an alternative to public-switched telephone networks (“PSTNs”) for placing telephony calls. 
     FIG. 1  depicts a schematic diagram of a system  100  for voice communications over a data network in the prior art. The system includes data network  102  and public-switched telephone networks (“PSTN”)  120  and  122 . The specifics of the architectures and communications protocols of such systems are not described herein except to note that they are quite different from one another such that direct communication therebetween is not possible. It will be appreciated that while two PSTNs (i.e., PSTN  120  and  122 ) are depicted, there is, at least functionally, only one worldwide PSTN. 
   Communication between a PSTN and a data network is implemented via a “gateway.” A gateway is an entrance to and an exit from a communications network. A gateway is typically an electronic repeater device that intercepts and translates signals from one network to another. A gateway often includes a signal conditioner that filters out unwanted noise and controls characters. In data networks, gateways are typically a “node” on both networks that connects two otherwise incompatible networks. Thus, gateways often perform code and protocol conversions. Such an operation would be required for communication between a PSTN and a data network. Assuming an analog voice signal is delivered from the PSTN, the gateway digitizes that signal from the PSTN and encodes it and transmits it as “packets” (hereinafter “digitized voice signal”) over the data network according to data network protocols. In other embodiments, the signal from the PSTN is a digital signal, such that analog-to-digital conversion is not required. Protocol conversion is still required. 
   An element associated with a gateway is a “gatekeeper.” A gatekeeper is responsible for gateway registration, address resolution and the like. A gatekeeper may be viewed as the router that directs a digitized voice signal to a “terminating” gateway (i.e., a gateway that provides protocol conversion for transmission over a PSTN, for example, to a telephone). As used herein, the term “gateway” includes both the gateway and gatekeeper functions. 
   System  100  therefore also includes gateway  110  that acts as a conduit between PSTN  120  and data network  102 , and gateway  112  serving as a conduit between data network  102  and PSTN  122 . The system further includes telephone  130  that is connected, via link L 1 , to PSTN  120  and telephone  136  that is connected, via link L 8 , to PSTN  122 . The links that are depicted in  FIGS. 1 and 2  are, as is well known, trunk lines, trunk groups, etc., as appropriate. 
   In operation, voice message  140  from telephone  130  is transmitted over link L 1  to PSTN  120 . Within PSTN  120 , voice message  140  is routed to switch S 2  over link L 2 . Switch S 2 , the operation of which is well known in the art, will typically route voice message  140  to another switch (not shown) over a trunk group (not shown). In such a manner, voice message  140  moves through PSTN  120  being routed from switch to switch until it is carried over a final link L 3  out of PSTN  120 . Voice message  140  is then carried, over L 4 , to gateway  110 . 
   “Originating” gateway  110  performs protocol conversion and digitizes, as required, voice signal  140 . Voice message  140  is then routed (the gatekeeper&#39;s function) into data network  102 . For clarity of presentation, the voice message will be assigned the same reference numeral (e.g.,  140 ), notwithstanding the fact that the signal carrying the message is physically changed during transmission through the system. 
   Message  140  is transmitted over call path DNCP to (call-) “terminating” gateway  112  wherein the signal leaves data network  102 . Note that the designation “originating” or “terminating” applies on a call-by-call basis. In other words, for a first call, a particular gateway can be an originating gateway, while for a second call, that same gateway can be a terminating gateway. Moreover, packets typically flow in both directions since both parties typically talk. 
   A call path through a data network, such as call path DNCP through data network  102 , is not fixed according to a defined hierarchy as in a PSTN. Rather, an originating gateway “selects” a terminating gateway and the voice signal is routed by successive network elements (e.g., routers, bridges, etc.) through the data network to the terminating gateway. Since routing decisions are made by each network element, call path DNCP is not a priori known or set. 
   Gateway  112  receives voice message  140  and converts it to a form suitable for transmission through PSTN  122 . Voice message  140  is delivered over link L 5  to PSTN  122 . Within PSTN  122 , voice message  140  is routed via over links, such as link L 6 , to switches, such as switch S 4 . Voice message  140  is carried over link L 7  out of PSTN  122  to link L 8  to telephone  136  to complete the call. 
   Such prior art systems typically suffer from significant drawbacks. Perhaps the most significant drawback is that on some data networks, such as the Internet, there are no means by which call (e.g., voice) quality is monitored and actively managed. As such, a need exists for a data-network-based telephony system that efficiently transmits telephone calls while actively managing quality of such transmissions. 
   SUMMARY OF THE INVENTION 
   In some embodiments, the present invention provides a distributed monitoring, evaluation and routing (“DiMER”) system that provides active management of a data-network-based telephony networks. Among other benefits, the DiMER system enhances voice quality of telephone calls that are placed over such networks. 
   In accordance with the present teachings, such a system, and data-network-based telephony networks incorporating the same, advantageously route calls to meet call-quality standards and/or cost goals, among other targets. Telephony networks in accordance with the present invention advantageously comprise the DiMER system, PSTNs, gateways and a data network. 
   In data-network-based telephony networks, problems can arise within the data network at any of a plurality of network elements, or, alternatively, at gateways themselves. Unlike PSTNs, which have a rigid, well-defined routing hierarchy, no fixed call route is a priori defined through a data network. As such, identifying a problematic network element, and rerouting to avoid such an element, is problematic. 
   In accordance with the present invention, the cause of problems arising within the data network is “ignored” for routing purposes. Rather, in the present invention, routing is addressed by focusing on the originating and terminating gateways. This approach is advantageously used because call routes over a data network to different terminating gateways are typically different. Thus, even though the route to a terminating gateway is not a priori known, whatever route is taken, that route is reasonably assumed to be uniquely associated with that gateway. As such, if compromised performance or a failed call attempt is detected, the terminating gateway (which is known) is the focus, regardless of the actual location of the problem (which can be hard to locate). 
   In view of the foregoing, and in accordance with the present teachings, the network is operated/administered/managed (i.e., operating goals for the network, whether they be cost, quality or other targets, are achieved) by shifting or reallocating call traffic between available terminating gateways based on system performance. 
   To implement such an approach, “problem” gateways must be identified. In the embodiments described herein, such identification is performed by (1) obtaining call-related data (hereinafter “call metrics”) from gateways via a “data acquisition element;” and (2) adopting a mode of analysis that readily identifies such problem gateways. In the illustrated embodiments, the analysis function is advantageously performed by an “analysis element” via a mode of analysis referred to herein as “banding.” It will be understood that “banding,” which is described later in this Specification, is simply one of a variety of suitable approaches for data analysis as may occur to those skilled in the art in view of the present teachings, and that such other methods may suitably be used. 
   Once a mode of analysis is adopted (e.g., “banding”), call metrics are advantageously organized or processed into a form that is useful for that mode for analysis. Moreover, having identified “problem” gateways, data must be organized in a way that facilitates shifting call traffic between acceptable gateways to meet quality standards or other goals. 
   To that end, and in accordance with an embodiment of the present invention, “portfolios” are generated. Each portfolio indicates, for a particular “DNIS,” the percent allocation or routing of call-traffic to “acceptable” gateways (i.e., gateways that can accept calls in the DNIS). Briefly, the term “DNIS” refers to a collection of digits within a telephone number that can be used to identify telephone numbers having such digits as belonging to a particular group or “dialing plan.” For example, “732” can be a DNIS. Further description of DNIS is provided later in this Specification. 
   An initial call-traffic allocation within a portfolio is developed by the network administrator based on internal policy considerations (e.g., cost, quality, etc.). Changes are made in each portfolio (i.e., shifting the allocation of call traffic among the various acceptable terminating gateways) as a function of recent network performance (as indicated by the collected and processed call metrics) among any other parameters, to meet the business objectives of the network administrator. In some embodiments, such allocation is based on “best value routing,” which considers both call quality and cost in the allocation calculus. Such changes are made by a “routing element.” 
   Once a new allocation is established within the portfolio, such allocation must be implemented. An illustrative methodology presented herein for implementing the revised allocation involves using historical data that provides a breakdown of call traffic for each DNIS by “sub-DNIS” (i.e., the next significant digit following the DNIS). Sub-DNIS are “allocated” to each gateway (i.e., telephone numbers within the sub-DNIS are route to an appropriate gateway) as required to satisfy the desired call-traffic allocation. 
   In a further embodiment of the present invention, a router is placed in direct communication with a customer premises equipment (CPE) such as a telephone or computer. The router examines properties of the dialed telephone number, and determines whether the number is within a specified class. Depending upon the outcome, the call may be routed to either an Internet gateway or directly to a telephone switch. 
   Calls routed through an Internet gateway are routed by having two data devices examine the called telephone number. The first examination of the called number is performed by the router, in order to ascertain whether to route the call over the Internet or the telephone network. While such an examination occurs, the call may be “parked” at the router, and the calling number may be preferably stored for later use by the system in connection with authentication and authorization. 
   The second examination of the called telephone number occurs at an originating gateway to which the call is routed, if the Internet (or other data network) is selected. If such data network is selected, the originating gateway or other computer with preferably access the stored calling number from the router and perform authentication and authorization services in order to ensure that the calling number is a number authorized to use the data network for such telephone call. The router may also select from among plural originating gateways, and each originating gateway may select from among plural terminating gateways. 
   Other aspects of the present invention will become more clear from the following Detailed Description and the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  depicts voice communications over a data network in the prior art. 
       FIG. 2  depicts a high-level schematic diagram of a data-network-based telephony system in accordance with an embodiment of the present invention. 
       FIG. 3A  depicts a high-level flowchart of an illustrative method for monitoring, evaluating and routing functions of the system of  FIG. 2 . 
       FIG. 3B  depicts a high-level schematic diagram of basic functional elements of an illustrative distributed monitoring, evaluating and routing system in accordance with the present teachings. 
       FIG. 4  depicts further illustrative operations comprising a method in accordance with the present invention. 
       FIG. 5  depicts further detail of one of the functional elements shown in  FIG. 3B . 
       FIG. 6  depicts further detail of the functional elements shown in  FIGS. 3B and 5 . 
       FIG. 7  depicts an illustrative example of banding. 
       FIG. 8  illustrates an exemplary embodiment of a CPE router in conjunction with gateways in accordance with the present invention. 
       FIG. 9  is a flowchart of the method used in conjunction with the system of  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   For clarity of explanation, the illustrative embodiments of the present invention are presented as a collection of individual functional blocks. The functions that such blocks represent can be provided using either shared or dedicated hardware, including, without limitation, hardware capable of executing software. Illustrative embodiments may comprise digital signal processor hardware, read-only memory (ROM) for storing software performing the operations described below, random-access memory (RAM) for storing DSP results and for storing collected-call information, and non-volatile memory for storing pre-established rules for evaluating call quality. 
     FIG. 2  depicts a portion of data-network-based telephony network (“DNT”)  200  in accordance with an illustrated embodiment of the present invention. From a high-level perspective, the present network comprises a distributed monitoring evaluation and routing (DiMER) system  201  that is used in conjunction with elements of a standard network-based telephone network, such as network  100  depicted in  FIG. 1 . Such standard elements include “gateways” that facilitate communications between PSTNs and data networks (see Background section). As described further below, the “intelligence” imparted from DiMER system  201  to “originating” gateways, among other network elements, distinguishes the performance and operation of such gateways and DNTs incorporating the same, from those in the prior art. 
   The depicted portion of illustrative DNT  200  includes, among other elements, DiMER system  201 , data network  102 , two PSTNs  120  and  122 , four gateways  210 ,  212 ,  214  and  216 , and three wire-line telephones  130 ,  136  and  236 , interrelated as shown. Gateway  210  serves as an interface between PSTN  120  and data network  102 . Similarly, gateways  212 ,  214  and  216  function as an interface between data network  102  and PSTN  122 . Telephone  130  is accessible over PSTN  120 , and telephones  136  and  236  are accessible over PSTN  122 . 
   Gateway  210  is depicted as an originating gateway, and gateways  212 ,  214  and  216  are depicted as terminating gateways. As previously indicated, the designation “originating” or “terminating” applies on a call-by-call basis, such that each gateway is both an originating gateway and a terminating gateway as a function of where the call originates and where it terminates. For clarity of explanation, originating and terminating gateways will, however, be treated as separate elements. Furthermore, it is understood that communication is bi-directional. It will be appreciated that implementations of the present network will typically contain many more gateways (scattered across the world) than the four gateways depicted in DNT  200 . 
   In operation, a calling party represented as telephone  130  calls into PSTN  120  over link L 1 , entering a destination telephone number for call or message  140 . For the purposes of illustration, the called telephone number corresponds to telephone  236 . 
   Within PSTN  120 , call  140  is carried over link L 2  to switch S 2 , which, in one embodiment, is assumed to be a client of the administrator of data-network-based telephone network in accordance with the present teachings. In such an embodiment, switch S 2  routes call  140  to the administrator&#39;s central office  220  over link L 9 . In alternative embodiments, a call can be placed directly into central office  220 . Central office  220  routes call  140  over link L 11  to switch S 6 , which is advantageously controlled by the aforementioned administrator. 
   In some embodiments, switch S 6  includes “unified routing information.” In prior art DNTs, routing across the PSTN (e.g., switches) is treated separately and independently from the routing through the data network. The unified routing information of the present invention, advantageously provided in the form of a unified routing table, results from treating the PSTN and data network as elements of a single network. Unified routing provides an increased measure of control over the DNT in comparison with prior art systems. Such additional control can result in reduced costs to the administrator and/or increased control over call quality, among other benefits. 
   Based on the routing information in switch S 6 , call  140  is routed over links L 13  and L 14  to gateway  210 . In some embodiments, the calling party at telephone  130  must be authenticated as a valid user before gaining access to gateway  210 . 
   Having received a called telephone number, and a request to place such a call over a data network voice channel, gateway  210  generates or is provided with a list of termination gateways that can accept the call. In the illustrative embodiment depicted in  FIG. 2 , any of gateways  212 ,  214  and  216  can accept call  140  intended for telephone  236 , as is shown by links L 21 , L 26  and L 29  that link such gateways, via switches S 12 , S 14  and S 16  in PSTN  122 , to telephone  236 . A call intended for telephone  136  must, however, be routed to gateway  212 . From gateway  212 , that call is routed over link L 16  to switches S 8  and S 10  in PSTN  122  and then to telephone  136  over links L 19  and L 20 . 
   The list of “acceptable” termination gateways can be generated solely by gateway  210 , or, in other embodiments, in conjunction with other gateways. Prior art gateways are capable of generating a “list” of terminating gateways that are physically able to accept calls for a specified telephone number. Such a list may be “prioritized” wherein calls are initially routed to a first gateway. If the call cannot be completed by the first gateway, the call is routed to a second gateway, etc. Unlike the prior art, and in accordance with the present invention, a call allocation is specified for acceptable gateways. Such an allocation may dictate that 30 percent of the calls are directed to a first gateway, 45 percent of the calls are directed to a second gateway, and 25 percent of the calls are directed to a third gateway. 
   In one embodiment, the call allocation is based on call metrics obtained from originating and terminating gateways and the analysis of such call metrics. In another embodiment, call allocation is determined as a function of call quality (as determined by the call metrics) as well as the price charged by the gateway for terminating the call. Call allocations are advantageously periodically updated (e.g., hourly) based on real time data regarding system performance (i.e., the call metrics). 
   Based on the call allocation data, which is again advantageously provided in the form of a unified routing table, originating gateway  210  selects a terminating gateway to which to route the call among the acceptable gateways. For example, among acceptable gateways  212 ,  214  and  216 , the list may specify that terminating gateway  216  is allocated most of the calls, and it may be determined that at the present time it is appropriate to route call  140  thereto. 
   As routing through a data network does not follow a predefined hierarchy, the route taken through a network (i.e., from one network element to the next) from an originating gateway to a terminating gateway is not a priori known. As such, if problems arise, it may be very difficult to determine the cause/location of the problem. In the prior art, the cause or location of a problem is typically sought. 
   It is reasonably assumed, however, that the call path between an originating gateway and a first terminating gateway is different than the call path between the same originating gateway and a second terminating gateway. As such, and in accordance with the present invention, if a particular terminating gateway is having problems terminating calls (e.g., as determined from analysis of collected call metrics), calls are rerouted to another gateway. In other words, rather than trying to determine the cause/location of the problem as per the prior art, the call allocation among the gateways is changed. 
   Returning to the illustrative example (call  140  intended for telephone  236 ), after protocol conversion, etc., call  140  is routed to gateway  212 ,  214  or  216  as appropriate, over respective call paths DNCP 1 , DNCP 2  and DNCP 3 . Assuming that call  140  is sent to gateway  216 , that gateway performs the protocol conversion, etc., and directs the call over link L 29  to PSTN  122 . In PSTN  122 , call  140  is routed to switch S 14  over link L 30 , and from there to switch S 16  over link L 28 . Finally, call  140  is routed out of PSTN  122  via link L 24 , and delivered to telephone  236  over link L 25 . 
   In addition to connecting calls between wireline telephones, the present system and method is useful in conjunction with cellular telephones, such as cell phones  232  and  238  that are depicted in  FIG. 2 . In particular, if a call  240  is placed by cell phone  232 , that call is carried over cellular system  222  in well-known fashion and enters PSTN  120  over link L 32 . Call  232  is then processed as previously described and is routed from PSTN  122  into cellular system  222  and to cell phone  238 . Of course, a call may likewise be placed between a cell phone and a wireline telephone, so that only a single entry into cellular system  222  is necessary. 
   In a further embodiment, the present system and method is used in conjunction with a “pc-phone” or like device that bypasses PSTN  120 . In an illustrated embodiment, pc-phone  234  comprises a processor  240  running appropriate software, speakers  242  and microphone  244 . Call  248  from pc-phone  234  is carried over link L 36  to “gateway”  210 . Actually, the call from such a pc-phone typically bypasses the gateway and is directed, at least in some embodiments, to a gatekeeper (not shown). As previously noted, as used herein, the term “gateway” incorporates the functions of a “gatekeeper.” 
   As previously noted, after the call is terminated, quality-related metrics information pertaining to the call is transmitted from the terminating gateway (e.g., gateway  216 ), and, in some embodiments, the originating gateway (e.g., gateway  210 ) to DiMER system  201 . In some embodiments, call quality is determined by DiMER system  201  from call metrics  262 ,  264 ,  266 ,  268  that are carried over links  262   a ,  264   a ,  266   a  and  268   a  to DiMER system  201 . Likewise, the routing information that is generated by DiMER system  201  is based, for example, on such call quality, cost information and current route information  270  carried over link  270   a  from originating gateway  210 . Routing information  280  developed by DiMER system  201  is transmitted to originating gateway  210  over link  280   a.    
   Having described the manner in which a call is placed over the present telephony network and the data flow between the “standard” network elements and those of distributed monitoring and evaluation system  201 , it is now appropriate to describe, in detail, DiMER system  201  and its operation. The description proceeds with reference in  FIGS. 3A–6 . 
     FIGS. 3A and 3B  provide a “high-level” description of the functional operation and organization of DiMER system  201 . In particular,  FIG. 3A  depicts a high-level flow-diagram of a method of operation for an illustrative embodiment of DiMER system  201  and  FIG. 3B  depicts a schematic diagram of basic functional elements for implementing such operations.  FIG. 4  depicts more detail of illustrative operations that comprise a method of operation in accordance with the present invention,  FIG. 5  depicts additional information concerning an illustrative architecture of one of the basic functional elements depicted in  FIG. 3B , and  FIG. 6  depicts further information concerning an illustrative architecture of DiMER system  201 . 
   It will be understood that architecture depicted for DiMER system  201 , such as that depicted in  FIGS. 3B ,  5 ,  6 , etc., is merely illustrative. Such architecture, and the association of specific functions therewith, is for pedagogical purposes and for clarity of presentation. As a result of its “distributed” nature, DiMER system  201  may advantageously be organized in a wide variety of ways as will occur to those skilled in the art to provide active management. 
   In an illustrative embodiment, DiMER system  201  provides a data acquisition functionality, a data analysis functionality and a call routing functionality. Such functionalities are depicted in the flow diagram of  FIG. 3A  as collecting call metrics  302 , data analysis  304 , and call routing  306 . In view of such functionality, it is convenient to organize, at least conceptually, DiMER system  201  into three modules or elements for accomplishing such functions. Thus, in the illustrated embodiments, DiMER system  201  comprises a data acquisition element, a data analysis element, and a call routing element. 
   In an embodiment depicted in  FIG. 3B , such an architecture is realized by portfolio monitoring and reporting element  310 , network quality analysis and feedback element  320  and unified routing element  330 . Call metrics CM are obtained by portfolio monitoring and reporting element  310  from originating and terminating gateways (not depicted in  FIG. 3A ). After suitable processing, process metrics PM are delivered to network quality analysis and feedback element  320  for data analysis. Analyzed metrics AM are received by unified routing element  330  for generating revised routing tables. The revised routing tables RT, which are advantageously unified routing tables, are provided to originating gateways and, in some embodiments, to switches controlled by the network administrator (not depicted in  FIG. 3B ). 
   In the illustrative embodiments depicted in  FIGS. 5 and 6 , portfolio monitoring and reporting element  310  includes, among other elements, “local agents” (e.g., local agent  518 A and  518 B), “regional agents” (e.g., regional agents  520 – 524 ), and a “master collector  540 . In other embodiments, local agents are not used; rather, only regional agents and a master collector are used. As previously indicated, the “local agent” and the “regional agent” (and other functional elements, as well) are, at least in one embodiment, software that performs the functions attributed to such elements. 
   In the illustrated embodiments, portfolio monitoring and reporting element  310  ( FIG. 3B ) performs call metrics collection operations  302  ( FIG. 3A ). Although it is not depicted in the Figures, the illustrated architecture provides, in one embodiment, for a relatively greater number of widely-scattered local agents to report to a relatively smaller number of regional agents. For example, a regional agent located in Japan may monitor all local agents in Asia. The regional agents, in turn, report to a single master. Such a hierarchy, which proceeds from “local” (greatest in number)→“regional” (fewer in number)→“master,” (one in number) is a suitable approach for call metrics collection, processing, etc., in networks having a wide geographic coverage. It will be understood that other architectures may suitably be used for portfolio monitoring and reporting element  310 . 
   Moreover, it may be advantageous to use a different architecture for portfolio monitoring and reporting element  310  when used in conjunction with data-network-based telephony networks having less extensive geographic coverage or otherwise configured in a different manner than the illustrative network. It is within the capabilities of those skilled in the art, having the benefit of the present teachings, to develop and implement such different architectures. 
   Regarding call metrics collection operation  302 , such call metrics are advantageously collected from all of the gateways (originating and terminating) in the data-network-based telephony network. As described in more detail later in this Specification, such call metrics provide an indication of network performance and provide the basis for routing changes that are generated by unified routing element  330 . In the illustrative embodiments of DiMER  201  that are depicted in  FIGS. 5 and 6 , metrics collection is performed by “local agents”  518 A (reporting to “regional agent”  522 ) and  518 B (reporting to “regional agent”  524 ) or directly by regional agents  522  and  524 . 
   More particularly, in  FIG. 5 , call metrics  501  from gateway  211 , and call metrics  503  from gateway  213  are reported directly to regional agent  524 . Call metrics  505  from gateway  215  is reported to regional agent  522 . Local agent  518 A receives call metrics  507  from gateway  217 , advantageously provides preliminary processing of such call metrics  507 , as described in more detail later in this Specification, and provides processed call metrics  508  to regional agent  522 . Local agent  518 B receives call metrics  509  from gateway  219 , and reports processed call metrics  510  to regional agent  520 . 
     FIG. 6  provides further illustrative architectural details, wherein metrics collection from gateway  217  to local agent  518 A is implemented via metrics collector  612 A, and metrics collection from gateway  219  to local agent  518 B is implemented via metrics collector  612 B. In some embodiments in which DiMER  201  does not utilize local agents, call metrics are provided directly from a gateway, such as (originating) gateway  210  and gateway  215 , to an appropriate regional agent, such as regional agent  522 . It should be understood that while only two regional agents are depicted in  FIG. 6 , portfolio monitoring and reporting element  310  will typically comprise many more of such regional agents, as a function of the geographic scope of the network. Likewise, in embodiments in which portfolio monitoring and reporting element  310  comprises local agents, many more than the two such local agents depicted in  FIG. 6  will typically be used. 
   Local agent  510  can be located “at” a gateway. Such an agent is referred to herein as an “in-situ” local agent. In one embodiment, an in-situ local agent is realized as software running on a processor that is an element of a gateway. Alternatively, local agents can be situated at a remote location (e.g., software running on a processor that is physically remote from the gateway but in communication therewith). 
   Collected call metrics retrieved from gateways include, without limitation, data suitable for evaluating average call duration, average percent call completion and average “port” utilization (each gateway has a plurality of ports (e.g., 20) available for completing a call). It will be appreciated that the metrics listed above may be derived quantities that are calculated from “raw” data. It is within the capabilities of those skilled in the art to collect such raw data and to determine the specific data to be collected. In some embodiments, such average call duration metrics are not received directly from the gateways, but rather from a data storage site (e.g., data warehouse  550 , see  FIG. 5 ). 
   To facilitate analysis of the collected call metrics (operation  304 ), such call metrics are advantageously “processed” in accordance with operation  4022  (see  FIG. 4 ). Such processing involves summarizing or organizing the collected call metrics. It will be appreciated that the data is advantageously organized or processed to facilitate transmission of that data, in some embodiments, processed in a way that is most appropriate for the analysis method adopted in operation  304 . In the illustrated embodiments, such analysis is performed via “banding.” As will become clearer later in this specification, the call metrics are advantageously organized, at least in part, on “per gateway” basis to facilitate analysis via banding. 
   In illustrative embodiment of DiMER  201  depicted in  FIG. 6 , metrics retrieved by local agents are processed therein via a “metrics processor.” In particular, metrics processor  614 A in local agent  518 A processes call metrics collected by call metrics collector  612 A, and metrics processor  614 B in local agent  518 B processes call metrics collected by call metrics collector  612 B. In embodiments in which regional agents, such as regional agent  522 , directly retrieve call metrics via a call metrics collector (e.g., collector  622 ), such call metrics are processed via an associated call metrics processor (e.g., processor  624 ) within the regional agent. 
   In large networks, the processed call metrics may benefit from some amount of “consolidation” before analysis. In the illustrative architecture of DiMER  201  depicted in  FIG. 6 , a consolidation operation  4024  is performed by regional agents, such as regional agents  522  and  520 , in a consolidated metrics processor, such as processor  626  associated with regional agent  522  (consolidated metrics processor not shown for regional agent  520 ). 
   Thus, call metrics (e.g., call metrics  505 ) obtained (and processed) directly by a regional agent (e.g., regional agent  522 ), or that are obtained by the regional agent indirectly through local agents, are “consolidated” for ease of transmission, etc. 
   Consolidated processed metrics (e.g.,  531 ,  533 , etc.) are provided to master collector  540  ( FIGS. 5 and 6 ). Central collector  632  within master collector  540  receives consolidated processed metrics from all regional agents in the system. Consolidated processed metrics  635  are delivered to portfolio generator  634  in master collector  540 . As depicted in  FIG. 5 , master collector  540  is advantageously in communication with output device  560 , which can be, for example, a display monitor or the like device for displaying collected data. 
   As DiMER  201  advantageously generates revised routes by shifting call traffic between acceptable gateways, data is advantageously organized in a way that facilitates such shifting. To that end, and in accordance with operation  4026  of an illustrative embodiment of the present invention, a plurality of “portfolios” are generated from the consolidated processed metrics by a “portfolio generator.” In  FIG. 6 , portfolio generator  634  is depicted as being located in master collector  540 . 
   Each portfolio provides “statistics” for one “DNIS.” “DNIS” is an acronym for Dialed Number Identification Service. While often defined as a feature of 800 and 900 lines, the term “DNIS” is used herein to refer to a set of digits defining a dialing plan. For example, in the phone number (732) 555-1212, the digits “732” form an illustrative DNIS. Thus, the DNIS “732” includes all telephone numbers having the area code “732.” Each DNIS may further comprise a plurality of “sub-DNIS.” Given a DNIS “732,” there are potentially ten sub-DNIS “732x.” Thus, 7320, 7321, 7322, 7323, 7324, 7325, 7326, 7327, 7328 and 7329 are all sub-DNIS of the DNIS “732.” The sub-DNIS “7325,” for example, includes all telephone numbers having the area code “732” and having an exchange that begins with the digit “5.” And, in turn, the sub-DNIS “7325” can be divided into sub-DNIS “7325x,” and so forth. 
   The statistics provided by a portfolio include a call breakdown on a per-gateway basis. In other words, given the total calls for a particular DNIS, and given all gateways that terminate calls for the DNIS, the portfolio provides the percentage of calls terminated by each such gateway. Table I provides an illustrative portfolio for the DNIS “ 201 .” 
   
     
       
             
           
             
             
             
           
         
             
               TABLE I 
             
           
           
             
                 
             
             
               Illustrative Portfolio for DNIS 201- 
             
           
        
         
             
                 
               Gateway 
               % of Call Traffic 
             
             
                 
                 
             
             
                 
               GW1 
               20 
             
             
                 
               GW2 
               30 
             
             
                 
               GW3 
               40 
             
             
                 
               GW4 
               10 
             
             
                 
                 
             
           
        
       
     
   
   Thus, for the example of Table I, gateway GW1 terminates twenty percent of the calls having the DNIS “201.” Similarly, gateways GW2, GW3 and GW4 terminate thirty, forty and ten percent, respectively, of the calls having the DNIS “201.” The portfolio thus converts the collected call data from a “gateway-centric” view to a “DNIS-centric” view. In some embodiments, a portfolio is based on a combination of historical and real-time data (e.g., the real-time data is “blended” in to adjust historical allocations). 
   Consolidated call metrics  633  are provided to network quality analysis and feedback element  320  for analysis operation  304 . In accordance with the present teachings, such “analysis” is advantageously performed via “banding,” operation  4042  and comparison operation  4044  (see  FIG. 4 ). In the embodiment depicted in  FIG. 6 , banding is performed by banding exception generator  670  in network quality analysis and feedback element  320 . 
   “Banding” defines an acceptable range for a given call metric at a given gateway or per DNIS as a function of time (e.g., hours of the day, days of the week, weeks of the month, etc.). The “acceptable range” for a specific call metric is developed using historical data, which, in an illustrated embodiment, is available as historical data  552  from data warehouse  550  (see  FIG. 5 ). 
   Consolidated call metrics  633 , which advantageously provide network performance on a time basis, are compared (e.g., operation  4044  in  FIG. 4 ) to the band defining acceptable performance. In such a manner, unacceptable performance is readily identified. Banding/comparison thus provides a terminating gateway&#39;s or DNIS&#39;s performance, as a function of time, for a specific call metric. The call metrics that are analyzed via the banding operation include, without limitation, percent call completion, average call duration and port utilization. As such call metrics are analyzed on a common basis (e.g., time), they can be considered in combination (e.g., applying weighting factors, etc.) to develop a single quality-assessment parameter. 
   An example of banding is depicted in  FIG. 7 , wherein percent call completion data is banded for a given gateway. The illustrative data used for the plot depicted in  FIG. 7  is provided below in Table II. 
   
     
       
             
           
             
             
             
             
             
           
         
             
               TABLE II 
             
           
           
             
                 
             
             
               Data for Banding Example of FIG. 7 
             
           
        
         
             
                 
               Upper 
               Lower 
               % 
               Out of 
             
             
               Time 
               Limit 
               Limit 
               Compl. 
               Band 
             
             
                 
             
             
               12 p.m.  
               70 
               50 
               65 
               No 
             
             
               1 p.m. 
               65 
               45 
               30 
               Yes 
             
             
               2 p.m. 
               60 
               40 
               35 
               Yes 
             
             
               3 p.m. 
               60 
               40 
               50 
               No 
             
             
               4 p.m. 
               65 
               45 
               57 
               NO 
             
             
               5 p.m. 
               67 
               45 
               55 
               No 
             
             
               6 p.m. 
               70 
               50 
               47 
               Yes 
             
             
               7 p.m. 
               67 
               47 
               49 
               No 
             
             
               8 p.m. 
               65 
               45 
               50 
               No 
             
             
               9 p.m. 
               60 
               40 
               55 
               No 
             
             
               10 p.m.  
               65 
               45 
               60 
               No 
             
             
               11 p.m.  
               65 
               45 
               55 
               No 
             
             
               12 a.m.  
               65 
               45 
               50 
               No 
             
             
                 
             
           
        
       
     
   
   The banding operation for the illustrated gateway indicates the percent call completion is “out-of-band” (i.e., sub-standard) at 1 p.m., 2 p.m. and 6 p.m. for the illustrated gateway. The banding operation for other gateways (not illustrated), indicates that percent call completion is “in-band” (i.e., meets standards) at 1 p.m., 2 p.m. and 6 p.m. 
   Thus, data for each reporting gateway is “banded,” in accordance via operations  4042 / 4044 . The banding data, which, as indicated above, may be on a gateway basis, is cross correlated with the portfolios to relate DNIS to Gateways. 
   The portfolios (generated in portfolio generation operation  4026 ) and the results of banding (generated in analysis operation  304 ), collectively referenced as data  671  (see  FIG. 6 ), are provided to unified routing element  330  to generate new routings per operation  306 . In accordance with the illustrated embodiments, the new routings are developed by generating a new gateway allocation, as per operation  4062 . The allocation is implemented via operation  4064  by sub-DNIS allocation, as described below. 
   In the illustrative architecture depicted in  FIG. 6 , data  671  is received by unified route generator  674 . Moreover, in the embodiment depicted in  FIG. 6 , current routing information  270  is extracted via current route extractor  672  from gateway  210  and provided to unified route generator  674 . 
   Based on the banding data, portfolio information and current routing information  270 , a revised call-traffic allocation between gateways for each DNIS is developed. In addition to using call quality, such as may be obtained from the banding/comparison operations, as a basis for cal-traffic re-allocation, cost data and other factors can be considered as well. In one embodiment, the revised allocation is based on both call quality and cost. It is within the capabilities of those skilled in the art to develop algorithms that apply appropriate weighting factors, based on company policy/goals, to quality data, cost data and any other parameters appropriate for consideration when re-allocating call traffic between gateways. Such routing table revisions can be performed on a periodic basis (e.g., hourly) to reflect network performance as determined by the banding operation. 
   Table III below provides illustrative data showing current routing information and a re-allocation of call traffic between gateways for a given DNIS in accordance with the present teachings. 
   
     
       
             
           
             
             
             
           
         
             
               TABLE III 
             
           
           
             
                 
             
             
               Illustrative Call Routing Guidelines 
             
             
               Percent of Call Traffic for DNIS 609 
             
           
        
         
             
                 
               Current 
               Revised 
             
             
               Gateway 
               Routing 
               Routing 
             
             
                 
             
             
               GW1 
               20 
               10 
             
             
               GW2 
               40 
               35 
             
             
               GW3 
               30 
               40 
             
             
               GW4 
               10 
               15 
             
             
                 
             
           
        
       
     
   
   In one embodiment, the revised allocation is implemented using historical data that provides sub-DNIS for the DNIS under consideration, as per operation  4064 . An example of such historical data is provided below in Table IV. 
   
     
       
             
           
             
             
             
           
             
             
             
           
         
             
               TABLE IV 
             
           
           
             
                 
             
             
               Distribution of Call Attempts for 609x 
             
           
        
         
             
                 
               Sub-DNIS 
               % Distribution 
             
             
                 
                 
             
           
        
         
             
                 
               6090 
               0 
             
             
                 
               6091 
               10 
             
             
                 
               6092 
               20 
             
             
                 
               6093 
               10 
             
             
                 
               6094 
               10 
             
             
                 
               6095 
               20 
             
             
                 
               6096 
               5 
             
             
                 
               6097 
               5 
             
             
                 
               6098 
               15 
             
             
                 
               6099 
               5 
             
             
                 
                 
             
           
        
       
     
   
   Thus, one way to implement the revised allocation shown in Table III is to allocate sub-DNIS 6096 and sub-DNIS 6097 to GW1 (10%); sub-DNIS 6091, 6092 and 6099 to GW2 (35%); sub-DNIS 6093, 6094 and 6095 to GW3 (40%) and sub-DNIS 6098 to GW4 (15%). 
   As previously indicated, in the prior art, routing through the PSTN is performed without any consideration of the routing across the data network (i.e., originating gateway to terminating gateway). In accordance with some embodiments of the present invention, a switch and gateway (or trunk group) form a “cluster” and are jointly considered in developing a routing scheme. Such consideration results in improved efficiency and increased control over network performance. 
     FIG. 8  depicts a further embodiment of the invention comprising a network having a PSTN and a plurality of gateways  806 ,  808 , and  812  in communication with a data network  807 . An exemplary call initiating telephone  801  is connected through a Customer Premises Equipment (CPE) router  802 . The router  802  is capable of examining a telephone call&#39;s signaling and of performing conventional least-cost routing types of selection. A PSTN incoming switch  803   a  is shown connected through a PSTN  804  to an outgoing PSTN switch  803   b  or  803   c . All PSTN switches, although designated as incoming or outgoing, are interchangeable and differ only in their current function. 
   In operation, a telephone call is initiated by telephone  801 , and the dialed digits are transmitted to router  802 . Although a telephone  801  is shown and described by way of example, such a telephone represents any one of various types of terminals, for example, a modem, fax, or computer device. In any case, the dialed digits are transmitted to router  802  for examination and processing. 
   Programmed into router  802  is a table of dialed properties of numbers that correspond to telephone numbers to be accessed over the data network  807 , for example the Internet, and/or telephone numbers to be accessed over the PSTN telephone network  804 . It is not critical how the information stored within router  802  is utilized to distinguish the calls which are to be transmitted via a data network from the calls which are to be transmitted via a PSTN. Thus, the table could include all area codes for which it is desirable to transmit calls over a data network, e.g., the Internet, with all others defaulting to the PSTN  804 . Alternatively, the information within router  802  may identify all long distance calls, since more digits are dialed for such calls, and the numbers are typically flagged by a leading “1,” and route all or most long distance calls via data network  807 . Regardless of the technique used, router  802  is utilized to identify and route calls with predefined characteristics to the data network  807 , and calls with other characteristics to the PSTN network  804 . 
   Once the routing decision is made by router  802 , the call is transmitted to PSTN  804  or via gateway  806  to data network  807 . The call is typically routed through incoming switch  803   a  to PSTN  804  if the dialed number is local, and further transmitted through outgoing switch  803   b  to local telephone  811   a . The call is also routed to PSTN  804  if the dialed number is distant, but there is no reasonable data network access, in which case the call is transmitted through outgoing switch  803   c  to distant incoming switch  810  of second PSTN  809 ; the call is next sent by PSTN  809  through outgoing switch  815  to distant telephone  811   b . Data network access may not be available, for example, if the originating gateway is overloaded, or no terminating gateway is available in the location to which the call is destined. 
   If the intended destination of the call is not local and is reasonably accessible through a data network, router  802  will route the call to an originating gateway  806 . Additionally, the router  802  may determine by an examination of the dialed number to which of plural originating gateways  806  (only one illustrated) the call should be routed. Such a feature would be advantageous, for example, if the originating gateways are capable of completing calls to different locations at different prices with respect to one another. 
   The properties of numbers or other information in router  802  may be altered as needed by transmitting a revised instruction via a communications channel  819  and through PSTN  809  and PSTN  804 . For example, one or more of the monitored parameters discussed above is caused to change by a Network Operations Center (NOC)  818  instruction forwarded to router  802 , and to one or more gateways. Such changes may be utilized to affect choices made by router  802  both as to network selection and the gateway or switch within a network for connecting calls of a specified class. 
   A still further aspect of the invention is implemented through use of a computer  813  and a database  814  that are accessed by typical initiating gateway  806 . Computer  813  and database  814  are optionally connected from originating gateway  806  through network  807 . The communication from router  802  connects through gateway  806  and network  807  to computer  813 . After the authorization process, the call request passes to gateway  806 . As will be described in detail with reference to  FIG. 9 , upon receipt by originating gateway  806  of an incoming call request, computer  813  accesses database  814  before processing the call to determine whether the call initiator is authorized to employ the system. If the caller is authorized, an approval message is sent to router  802 , which responds by sending the called number to the gateway  806 . Gateway  806  operates through data network  807  to identify a best value routing (BVR) to a selected output gateway  808  or  812 , then sending the called number via the BVR to the selected second gateway. The second gateway connects to the second PSTN node  809 , which completes the call to receiving telephone  811   b.    
   Referring now to  FIG. 9 , a flowchart of the present invention is illustrated with respect to the steps taken by the apparatus shown in  FIG. 8 . The router  802  ( FIG. 8 ) receives a dialed number in step  901  and determines, based on programmed information, whether the dialed number involves a particular type of call, e.g. a local call, in step  902 . If the dialed number is for a local call, the call is passed through a PSTN in step  903  to complete the call. If the dialed number is not for a local call, the system determines in step  904  whether the dialed number is for a destination that is accessible through a data network. If the dialed number is not for a data network-accessible destination, the call is passed through the PSTN at step  905 , following which the PSTN determines long distance routing to be utilized and completes the call. 
   If the dialed number is for a data network-accessible destination, the dialed number is now cached, or parked, at the router in step  906  and the router acquires the caller&#39;s identifying number in step  907 . The steps required to initially set up the call are performed using an out of band network, such and the SS 7  standardized signaling. 
   Having completed the basics to establish the desired call, the following steps are performed on the data and voice network as “in band.” A connection is made to an initiating gateway in step  908 , and the caller&#39;s identifying number is sent to a connected computer in step  909 . As described above, the connection may be made to the computer directly and only passed to the gateway after the authorization step. The computer accesses a database in step  910  and makes a determination in step  911  as to whether the caller is an authorized user of the system by comparison of information stored in the database. If the caller is not authorized, the call is terminated in step  912 . If the caller is authorized, an approval is sent in step  913  to the router which, in step  914 , sends the dialed number to the initiating gateway in band. 
   Note that the dialed number is sent in band, rather than the conventional telephony technique of sending the dialed number out of band during call set up, because a separate call is required from the router  802  to the gateway  806  before the dialed number is sent to the gateway  806 . Since most or all calls that are transmitted over data network  807  will be long distance calls, and since a call from router  802  to gateway  806  will normally be a local call, the router must substitute a local number for the long distance number when setting up the call using the SS 7  network. Only after the call from router  802  to gateway  806  is established is the actual called number sent to the gateway  806 , and even then, such called number is sent in band, over the already established communications channel between router  802  and gateway  806 . 
   The initiating gateway parks the dialed number in step  915  and attempts to locate a best value routing (BVR) destination gateway for the call destination in step  916 . The BVR routing decision involves determining, based on cost, load factors, and availability, a preferred terminating gateway to be used to complete the call. The dialed number is sent to the selected receiving gateway in step  917 , and the receiving gateway completes the call in step  918 . The call is then conveyed over the data network as previously described. 
   It is noted that the BVR techniques for routing the call over the Internet or data network need not be used in conjunction with the novel techniques used by the router. 
   It is to be understood that the above-described embodiments are merely illustrative of the invention and that many variations may be devised by those skilled in the art without departing from the scope of the invention. It is therefore intended that such variations be included within the scope of the following claims and their equivalents.