JP2009135984A - Service and information management system for telecommunications network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently accomplish various functions for call processing, fraud detection, and the like in a telecommunications network system. <P>SOLUTION: The present invention relates to a system for controlling and operating services for a telecommunications network. In particular, the present invention relates to an architecture and a method for a system of service control and operation elements. The system communicates with a plurality of interconnected telecommunications networks via a switching or signaling subsystem. The system provides and controls various functions of the telecommunications network. As their functions, for example, there are call processing and routing, automatic fault detection and correction, interactive service provision to clients, fraud detection and control, network abuse pattern identification, collection of data relating to call activities in respective network elements, and creation of a record of each call generated within the network can be cited. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates generally to service and operation control for telecommunications networks, and more particularly to a service control and operation component system that performs and controls various functions of telecommunications networks.

  Modern telecommunications network management includes call confirmation and routing, failure management, call detail records used to edit customer invoices, fraud detection and control, provision of new services, post-dial Several functions need to be performed, including delay time measurement and time synchronization. Currently, multiple systems within a telecommunications network perform these various functions.

  In a telecommunications network, information in the form of signaling messages is exchanged between network elements involved in call establishment and control. Exchanges, databases, etc. are used to exchange information.

Ordinary channel signaling is an out-of-band technique for exchanging information on a channel other than the channel used to transmit voice or data signals. One well-known signaling technique is the International Telegraph and Telephone Consultative Committee (CCITT) signaling system no. 7 (SS7) protocol is used. At the interface between AT &T's network equipment and a private branch exchange (PBX), a second well-known signaling technique is Q.264. The 931 protocol is used. In the SS7 protocol, a message is a highly structured information field of bits that is distinguished from each other by a length indicator. SS7 message format, and SS7 and Q. The relationship with the 931 protocol is CCITT's Blue Book, “Specification of Signaling System No. 7”.
6 (1988).

  Common channel signaling No. 7 for a general description of the G.7 protocol. G. Shanga's IEEE Journal on Selected Areas in Communication SAC-4, No. 3, pages 360-365 (1986); See Suzuki et al., Review of the Electrical Communication Laboratories, Vol. 28, No. 1-2, pages 50-65 (1980), each incorporated herein by reference.

  Network elements associated with a typical telecommunications network, such as AT & T's switching network, where calls are commonly routed include: (1) local switching within the caller's geographic area; The originating switching node associated with the network that receives the call request message from the carrier or competitor access provider and is responsible for controlling the setup of the call; (2) also related to the network, A terminating switch node that is within the called party's geographic area and connects the call to a local exchange carrier or private branch exchange associated with the called party; (3) a via switch. This is because the direct trunk line from the originating exchange node to the terminating exchange node is all busy, so the direct path between the originating exchange node and the terminating exchange node cannot be used. If there is an idle path that can be reached by activating with a switch to the terminal switch node, it is used to activate it. (For simplicity, references to via switches are omitted in the text and figures); (4) A service control point that serves as a database that informs the originating switch node about certain call processing and routing; And (5) a signal transfer that is placed in a connected pair and connected by an access link to the originating exchange node, the terminating exchange node and the service control point and used to transfer messages between network elements. point.

  A typical telephone called number in North America is of the form N0 / 1X NXX-XXXX. Here, N is an arbitrary number from 2 to 9, 0/1 is either 0 or 1, and X is an arbitrary number between 0 and 9. This 10-digit code generally represents, from left to right, a 3-digit area code, a 3-digit central office code, and a 4-digit station number. The area code number identifies the geographical area in North America, the central office code number identifies the central switching office serving the called party, and the station number provides the called party identification information.

  However, when the first three digits in the number are 800 or 900, the number is not directly associated with a geographic area. Some digits or all digits in an 800/900 type number usually have to be converted to the actual destination by the service control point. The service control point maintains a table of 800/900 numbers and the actual destination associated with that number. Such a conversion is called a global title conversion, and a table maintained by the service control point is called a global title conversion table. The switch and / or signal transfer point identifies which service control point serves which 800/900 number.

The signaling message flow for a typical call of type 800 NXX XXXX or 900 NXX XXXX traversing over various network elements is as follows.
The originating switch node receives a call request message, usually in the form of an initial address message, from a local switching network or competitor access provider serving the caller. The originating exchange node checks the message. If an error is detected in the message during the checking process, the call flow ends.

  If no error is detected in the message, the originating switch node consults its global title translation table to determine the identity of the service control point that can provide processing and routing programs for the call. The global title translation table includes entries representing all numbers serviced by the network (eg, 800 NXX XXXX or 900 NXX XXXX). For each dialed number, this table provides service control point identification information and the number of the subsystem identifying the application at that service control point. If the dialed number does not match an entry in the global title translation table, the table is incorrect or the local exchange carrier switch or competitor access provider switch misroutes the call. One of them.

  Assuming that a valid entry for the dialed number exists in the table, the originating switch node creates a query message (also called the transaction function application part message) and routes the call. And request processing information. The originating exchange node sends the inquiry message to the service control point identified by the global title translation table. In some existing systems, instead of the originating switch node, the signal transfer point looks up its own global title translation table and forwards a query message to the identified service control point.

  After receiving the inquiry message, the service control point creates a response message containing instructions for handling and routing the call and sends the response message back to the originating switch node. If the service control point learns that it will not service the dialed number received in the query message, it identifies the error in the response message. In this way, the reply message contains information for the processing and routing of the call or used to notify that the call has been aborted due to an error detected at the service control point Can do.

  The originating exchange node receives the response message and verifies it. Assuming that the response message was received and verified correctly, the originating switch node proceeds to route the call. As part of the routing function, the originating exchange node sends its request message to the terminating exchange node via the signal transfer point.

  After receiving the request message from the signal transfer point and verifying it, the terminating switch node forwards the request message to the local exchange carrier or private branch exchange serving the called party. However, if the private branch exchange is servicing the called party, the terminating exchange node is Q.D. Transfer the setup message (equal to the request message) to the private branch exchange using the 931 protocol. In both cases, forward signaling for the call is thereby completed.

  For a call that terminates on a local exchange carrier, the local exchange carrier's switch receives the called number, forwards the call to a known telephone destination, and sends an address complete message to the terminating switch node to call the called party. Indicates that attention has been drawn to an incoming call. When the call is terminated at the private branch exchange, the private branch exchange receives the called number and sends a call progress message and a warning message to the terminating exchange node.

  After receiving either the address complete message or the warning message, the terminating switch node plays the address complete message and sends it to the originating switch node. The originating exchange node forwards the address completion message received from the terminating exchange node to the local exchange carrier or competitor access provider exchange associated with the caller. Each switch provides an end-to-end connection to the audio path. The caller then hears the ringing sound coming back.

  When the called party answers the call, the called exchange carrier sends a reply message to the terminating exchange node, or the called private branch exchange sends a connection message. If the called party is a private branch exchange, the terminating exchange node sends a connection confirmation message to the private branch exchange. Upon receipt of either the reply message or the connection message, the terminating exchange node reproduces the reply message for the originating exchange node.

  The originating exchange node plays the reply message to the local exchange carrier or competitor access provider exchange associated with the originating party. After the caller and called party have a conversation and the caller hangs up, the local exchange carrier or competitor access provider switch sends a release message to the originating switch node. Next, the originating exchange node sends a release message to the terminating exchange node.

  In the case of a call completed for the local exchange carrier, the terminating exchange node sends a release message to the local exchange carrier. The local exchange carrier responds with a release complete message, so that the call is terminated. Q. for private branch exchanges. To break the 931 connection, the terminating switch node must send a disconnect message to the private branch exchange. Next, the private branch exchange is A 931 release message is sent to the terminating switch node. In response, the terminating exchange node is Q.D. A 931 protocol release complete message is sent to the private branch exchange so that the call is disbanded.

  The same call flow is usually applied when the dialed number includes an area code indicating the geographic area associated with the called party. However, the originating switch node uses the additional information from the automatic number identification table and the information from the dialed number table without sending an inquiry message to the service control point for routing and processing instructions. Often, these calls can be routed based on their own routing tables.

  When services are provided to network customers based on called and called numbers, an automatic number identification table and a dialed number table are maintained by each switch. Each table contains an enormous number of entries, and the number of entries increases as the service provided is expanded for a large number of subscribers.

  Network customers who maintain a number of 800 or 900 have subscribed to hourly routing services so that calls are directed to different phone destinations at different times of the day There are many. Converting an 800 or 900 number to an actual destination based on a time zone is performed by the service control point using its own local clock as a time reference. Typically, there is no provision for clock synchronization across the network, so if a local clock is not accurate, a customer's call with a time-based routing service can be directed to the wrong location There is.

  In addition to distribution by call destination and source, customers can also subscribe to data collection and reporting services that provide information regarding the distribution of 800 or 900 numbers by time of day, day of week, etc. This information is commonly generated by the service control point and sent periodically to a central computer. Instead, one device is placed on each input and output signaling link of SS7 to collect messages to and from each service control point.

  However, these data collection methods do not provide information about calls that failed during the call setup phase, such as calls that never arrive at the service control point. In addition, when a service control point collects data and sends it to a central computer, a portion of the processing capacity of that service control point is consumed to perform these functions, and on each link for each service control point It is cumbersome to arrange the apparatus to collect the data, and the method for collecting the data becomes expensive.

  The delay time after dialing, that is, the delay time from when the called number is dialed to when the ringing sound is received has become a direct measure of the quality of the network performance. Currently, there are limited mechanisms for monitoring delay time after dialing, so there is limited measurement of delay time after dialing.

  The call detail recording function for billing customers to the telecommunications network is usually performed by the originating exchange node. The originating switch node analyzes the call message corresponding to the call it controls as described above. When the switch node receives a response message containing processing and routing information for the call from the service control point, it sets the billing parameters for the call. The switch node records the time the callee answers and the time the connection is released, creating a detailed record of the call. The call detail record is forwarded to a data processing center where the data is processed periodically to calculate the customer's fee.

  By utilizing the originating exchange node to perform these functions, the flexibility for user-defined billing is limited, and real-time detection and misuse of telecommunications networks such as stalking It becomes impossible to control. A stalker is a person who makes a phone call for the purpose of annoying an opponent. When the called party answers, the stalker hangs up. Currently, the call is not charged and there is no record of abused calls on the stoker phone. Also, since data relating to the call is only collected periodically from the originating exchange node and other network elements, it is not possible to detect faults in the network in real time.

  Prior art systems have dealt with fault management in various ways, none of which are completely satisfactory. As one common practice, if an error is detected while the verification process is being performed by the network element, the network element responsible for verifying the message records data about the error. The network element is then polled to retrieve the error data, or programmed to report the error data to a central computer at predetermined time intervals. It is normal. This results in errors that occur during a period of time and remain undetected.

  Alternatively, selected calls entering the network system can be placed under supervision by setting a predetermined bit, called a supervision bit, in a message associated with a particular call. Messages with the watch bit set are copied and forwarded to the processing element by each network element through which the call has passed. As a result, for each selected call, a history is provided until the call fails. For details of such call monitoring, see Boothli U.S. Pat. No. 4,959,849. A network element architecture that is capable of exchanging messages with other network elements, reproducing the messages, and transferring the replayed messages over a data network to a central processor is also described above. In the US patent.

  Even with this call monitoring technique, the status of each call entering the telecommunications system may not be effectively and efficiently monitored in real time, resulting in errors that may not be detected.

  In one aspect of the invention, an apparatus for servicing telephone calls made within a telecommunications network includes a database and an interconnect bus for communicating with a communication unit. The communication unit communicates with the interconnected network element and directs the network element regarding the routing of calls passing through the network element. Information associated with each call is transmitted to the communication unit for storage in the database. In another aspect of the invention, the communication unit creates a record for billing purposes for calls passing through the network element.

  In yet another aspect of the invention, an apparatus for servicing telephone calls in a telecommunications network includes a processor, a database, and an interconnect bus for communicating with a communication unit. A program existing on the processor is executed to control various functions of the network. Information packets containing data supporting the functions of the network are transmitted between the interconnected network elements and the communication unit.

  In the preferred embodiment, a program residing on the processor allows the device to perform various functions associated with its telecommunications network centrally. These functions include call handling and routing, automatic fault detection and correction, interactive service delivery to customers, fraud detection and control, network abuse pattern identification and within the network. For example, creating a record for each call made.

  In addition, the present invention includes a method for recording information generated by an interconnected network element in response to a call passing through the network element. In accordance with this method, the originating network element receives information from all network elements that provide a path through the network for the call. The originating network element copies the message, appends information to the message, and includes the error signal so that the copied message and the appended information form an individual information packet, Transfer the information packet to the communication unit. The communication unit causes the information packet associated with each call in the network to be stored in the database. The information packet database is used to provide various functions of the telecommunication network.

  In one preferred embodiment, in response to the error indicated in the information packet, one test call is initiated and terminated at the communication unit. In response to this test call being made, each network element sends an indication of all messages generated / received by that element to the communication unit via information packets. These information packets are also stored in the database. In this way, a complete set of data is generated for each call in which an error is detected so that various error sources can be identified and corrected.

  In yet another aspect, the present invention includes a second method for establishing a pass-through path for calls on interconnected network elements. According to this method, the first network element detects a request message for a passage route, forwards the message to subsequent network elements in the passage route, copies the message, and Including the portion indicating that the second network element is seeking instructions for handling and routing the call, and the copied message and the added information are one An information packet is formed and forwarded to a central location having a data table containing processing and routing instructions for individual calls. When the data table is referenced to determine the necessary processing and routing for the call, a message containing processing and routing instructions for the call is transmitted to the second network element. The second network element correlates the request message with the message transmitted from the central location.

  In the preferred embodiment, the second network element is the originating network element. Thus, the selected interconnected network element through which the call passes sends a message to the originating network element. The originating network element forwards the information packet associated with the message to the communication unit, which correlates the information packet associated with the request message with the information packet provided by the originating network element. Information packets associated with a particular call are stored in the database.

  The advantages of the present invention will be readily apparent to those skilled in the art from the following detailed description. In this description, preferred embodiments of the invention are described. As will become apparent from the following description, the invention is capable of other and different embodiments, and its details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and are not limiting.

1 shows an overview of management of a telecommunications system according to the present invention. Fig. 2 shows a block diagram architecture of an exchange and signaling subsystem connecting an operating element with a network element of a telecommunications system. FIG. 6 shows information packets each containing messages and transaction information sent by the originating exchange node to the operating element for a call originating from one local exchange network and completing to one local exchange network. Fig. 2 shows a typical information packet sent by a network element to an operating element. Fig. 2 shows an illustrative architecture of operating elements for managing a telecommunications network according to the present invention. Fig. 3 shows three message flows for the call control function implemented by the operating element, in accordance with a preferred embodiment of the present invention. Fig. 4 illustrates an exemplary message flow for a call control function according to a second embodiment of the present invention. FIG. 5 illustrates an exemplary message flow for a call control function in accordance with a third embodiment of the present invention. FIG. 6 illustrates a message flow generated by the result of a signal transfer point routing error, in accordance with a preferred embodiment of the present invention. FIG. Fig. 4 illustrates the use of an automatic test call originating and terminating in the operating element, and a method for identifying and correcting in real time a routing error at a signal transfer point. Fig. 4 illustrates a message sent to an operating element during a case worker-initiated test call that occurs at the operating element and terminates at a local exchange carrier switch or a competitor access provider switch. Fig. 2 shows a typical message flow set up in a network and used to perform one part of a post-dial delay time measurement. Fig. 4 illustrates the use of an automatic test call originating and terminating in the operating element used to perform the other part of the delay time measurement after dialing. Fig. 3 shows a second method for calculating the total post-dial delay time for a single call. Shows messages related to initializing and synchronizing the network clock.

The present invention will be more readily understood after reading the following detailed description of certain illustrative embodiments of the invention in conjunction with the drawings.
FIG. 1 shows, in block diagram form, an overview of the management of a telecommunications system according to a preferred embodiment of the present invention. Service control and operation elements (hereinafter “operation elements”) 10 communicate via a data communication network 20 with a communication network 25 such as an AT & T exchange network. Data communication network 20 provides a T3 rate (45 Mbit / s) direct signaling link from operating element 10 to a number of elements associated with network 20. The network element shown in FIG. 1 includes an originating switch node 32, a service control point 33, a terminating switch node 35, and a plurality of signal transfer points 34. The originating exchange node 32 is connected to the customer's telephone 5 by a local exchange carrier exchange 31. The terminating switch node 35 is connected to the customer's telephone 5 by both the customer's private branch switch 37 and the local switch carrier switch 31.

  As shown in more detail in FIG. 2, the operating element 10 preferably includes a communication unit, such as an exchange and signaling subsystem 40. The subsystem 40 controls the connection of the operating element 10 to each network element associated with the telecommunications network 25 and includes a plurality of switching nodes such as an originating switching node, a plurality of signal transfer points 34 and a plurality of service control points 33. 32. A number of trunk line connections 22 provide at least 64 Kbit / s connections so that broadband communication tests can be performed through a managed telecommunications network 25. The switching and signaling subsystem 40 also includes an interface to the SS7 signaling link 23, which allows the subsystem 40 to interface with network elements using the SS7 protocol.

  In addition to interfacing with network elements such as switch node 32, signal transfer point 34 and service control point 33, switching and signaling subsystem 40 is a caller to case worker's station 45 for trouble reporting and customer inquiries. It also supports exchange. The subsystem 40 can also communicate with the voice recognition and voice response unit 41 so that the customer directly interacts with the operating element 10 to subscribe to a new service and the status of the order for the service, the billing contention etc. You can inquire about the status of. A computer test device 46 in combination with a transmission quality measurement system 47 allows the operating element 10 to perform a quality test on any interchanged path between switch nodes 32 (described below).

  Subsystem 40 is preferably such as that provided by an IEEE Future Bus, which is comprised of a number of processors and databases 10, 12 (further below) associated with operating element 10 via high speed interconnect 60. Communicate with). The switching and signaling subsystem 40 may have a direct connection to the call control database 11 and also to the information packet database 12. It is desirable that the same or different types of processors support, among other applications, an automated service provisioning program 51, a fault management application 53 and a fraud detection and control program 54 (described in further detail below).

  The call control database 11 includes a data table such as the automatic number identification table 1. Table 1 contains a list of telephone numbers and associated information regarding the services provided and the restrictions imposed, and dialed number table 2 is the dialed address associated with the called party and the processing of the call. And a list of instructions for routing, the network map table 3 provides which switch 32 and service control point 33 is served by which signal transfer point 34.

  When detailed instructions for call handling and routing are present at the service control point, the dialed number table 2 identifies the service control point and the subsystem number of the application at that service control point. The service control point has its own detailed number table (not shown) for the subset of dialed numbers that it serves. This dialed number table has pointers to customer records that contain detailed programs for call handling and routing. With this arrangement, feature-rich calls can be handled by that service control point and all other calls can be handled by the operating element.

  The customer record may also include the current address of the customer subscribed to the call forwarding service. The customer can have a call provided by dialing an 800 number and interactively provides the telephone number to which the call is to be provided.

  The automatic number identification table 1 is examined by the flow detection and control application 54 while the call is set up in the network 25. The flow detection and control application 54 compares the caller's telephone number against the automatic number identification table 1 and checks whether the caller's telephone number is marked as frozen. The flow detection application 54 examines the caller's billing profile to see if the caller's billing charges are delinquent and considers the impact of billing associated with unusually long calls being served by the network. If there is a suspicion of a flood, the flow control application 54 sends a message to the switch node 32 that is processing the call requesting the forced release of the call.

  The automatic service providing function 51 uses the databases 11 and 12. A customer requesting a new service is connected to a voice recognition and voice response unit 41 in the operating element 10. The customer is inquired about the subscription information interactively. The information provided by the customer is divided into a predetermined number of data entries for each uniquely defined service. While the customer is waiting, the automatic service providing function 51 verifies the information provided by the customer, and checks the automatic number identification table 1 to see if there is any fraud or charge delinquency associated with the customer's telephone number. To do. As soon as the customer hangs up, the operating element 10 creates a record of the customer associated with the requested service.

  FIG. 3 shows an exemplary message flow (time increases from top to bottom) for calls set up by a telecommunications network in accordance with the present invention. The call is completed from the local exchange carrier switch in the geographic area of the calling telephone 300 to another local exchange carrier switch 31 in the geographical area of the called telephone 302, and The call goes through several interconnected network elements such as originating switch node 32, service control point 33 and terminating switch node 35. The originating switch node 32 controls the call setup and receives the next message from the interconnected network element as the call passes through the network element.

  Request message 61, response message from operating element 10 instructing originating switch node 32 to send inquiry message 66 to service control point 33 to obtain routing and processing instructions for the call. 68, a response message 68 from the service control point 33 containing the routing and processing instructions for the call, an address completion message 63, a reply message 64 indicating that the called party can use to hold the conversation 69, and Release message 65. Some of these messages are transmitted through two or more network elements.

  The originating switch node 32 duplicates each message received from the network element and adds transaction information to each message. An information packet is formed by adding transaction information to this message. The information packet 200 is associated with the request message 61, the packet 201 is associated with the response message 62, the packet 202 is associated with the address completion message 63, the packet 203 is associated with the reply message 64, and the packet 204 is associated with the release message 65. Associated.

  Once generated, the information packet 200-204 is forwarded from the originating exchange node 32 to the operating element 10 via the exchange and signaling subsystem 40 (shown in FIG. 2). The operating element 10 receives the information packets 200-204 in real time, checks them and stores them. Referring to FIG. 2, the information packet associated with all calls serviced by telecommunications network 25 includes a database 12 of information packets. Various software applications, for example, reside on a processor in the operating element 10. The automatic service providing program 31 and the like use the database 12 and execute their assigned functions.

  FIG. 4 shows the structure of a typical information packet 80 sent to the operating element. The transaction information 81 added to the duplicated message 82 is usually 17 bytes long (each byte is 8 bits long). The transaction information field contains the following information: If there is a network ID 84, a cluster ID 85, and two or more synchronization elements, the operation element ID field 83 containing the member ID 86 associated with the operation element serving the call; Sender ID field 87 that identifies the network ID 84, cluster ID 85, and member ID 86 associated with the switch node; call ID field 91 that identifies the number assigned to the call by the originating switch node; call setup Sometimes an error code field 93 containing a value indicating the type of error detected if an error is detected by the network element; An interface type field 94 that identifies any of 931 message types.

  The information packet 80 associated with a particular call is correlated by the call ID 91, the sender's ID 87 (ie, the originating switch node associated with that call), and a time stamp 92 operating system.

  FIG. 5 shows an exemplary architecture of the operating element 10 for managing a telecommunications network in accordance with the present invention. Delay time measurement program 58 after dialing, detailed call recording program 52, flow detection and control program 54, fault management program 53, automatic service providing program 51, stoker identification service program 55, and network time monitoring and synchronization program Processors residing software applications that support the functionality of the operating element 10, such as 59 (all described in detail below), communicate with each other with the switching and signaling subsystem 40 over the high speed interconnect 60. . A database 12 of information packets associated with calls serviced by the network is accessible from each software application in the system. The call control database 11 can be consulted by the operating element 10 to determine call routing and processing (described in more detail below).

  A preferred embodiment of the call routing function performed by the operating element of the present invention is shown in FIG. FIG. 6 shows three types of situations distinguished by case 1, case 2, and case 3, respectively. Referring to case 1 of FIG. 6, when the originating exchange node 32 receives a request message 61 from the exchange 31 of the local exchange carrier associated with the caller, it adds transaction information to the message and sends an information packet 200. Forming and forwarding the information packet 200 to the operating element 10 to inform the operating element 10 that the originating exchange node 32 is requesting information regarding the routing and processing of the call.

  The operating element 10 examines the call control database (shown in FIG. 5) to determine whether it owns the requested call routing and processing instruction, or whether the instruction is at the service control point 33. know. If the operating element 10 possesses the appropriate processing and routing instructions for the call, the operating element 10 provides these instructions to the originating switch node 32 via a response message 62.

  On the other hand, as shown in case 2 of FIG. 6, when the call processing and routing instructions are at the service control point 33, the operating element 10 examines the call control database and the appropriate service to contact. A control point 33 is determined. The operating element 10 sends an appropriate response message 62 containing processing and routing instructions to the originating switch node 32 identified in the inquiry message 66 by the inquiry message 66. The service control point 33 is instructed.

  As shown in case 3 of FIG. 6, the operating element 10 knows whether it owns a direct path available for the service control point 33. If a direct path is not available, the operating element 10 sends a response message 68 to the originating exchange node 32 to instruct it to retrieve instructions from the service control point 33 identified in the response message 68. Then, the originating exchange node 32 sends its own inquiry message 66 to the service control point 33 and receives a response message 62 from the service control point 33 that includes processing and routing instructions for the call. When the response message 62 is received, the originating exchange node 32 adds transaction information to the message to form an information packet 201, forwards the information packet 201 to the operating element 10, and originates the exchange node 32. Informs the operating element 10 that it has received information about the routing and processing of the call from the service control point 33.

  As shown in FIG. 7, the second embodiment of the call routing function according to the present invention is a request message 61 to be received by the operating element 10 from the signal transfer point 34 rather than from the originating switch node 32. An information packet 205 associated with is provided. As shown in the preferred embodiment, the operating element 10 utilizes the call control database (shown in FIG. 5) to determine the necessary processing and routing for the call, and this information is provided by the response message 62. Forward to the originating exchange node 32. However, when the response message 62 is received, the originating switch node 32 must perform an additional function to correlate the response message 62 with the request message 61 received from the signal transfer point 34. This correlation is based on the identity of the exchange 31 of the local exchange carrier, the identity of the originating exchange node 32, and other information contained in the request message. Next, the originating exchange node 32 adds transaction information regarding the call to all subsequent messages that it sends to the operating element 10 as information packets 201-204. In addition, the operating element 10 must correlate subsequent information packets 201-204 received from the originating exchange node 32 with the information packet 205 received first from the signal transfer point 34. The aspects of FIG. 7 not described here are assumed to be the same as previously described with respect to FIG.

  The second embodiment is in a call where the originating switch node 32 subsequently needs to send an inquiry message 66 to the service control point 33 in order to obtain routing and processing instructions for the call. Although the delay time after dialing is slightly shorter, development is needed to correlate the request message 61 with the response message 62 in the switch node 32 (only one shown) on the originating side of the network.

  A third embodiment of the call routing function according to the present invention is shown in FIG. Signal transfer point 34 detects a request message 61 associated with the incoming call. The signal transfer point 34 adds transaction information to the request message 61 to form an information packet 205, and sends the information packet 205 to the stand-alone operating element 10. The operation element 10 uses a call control database 11 directly connected to the operation element 10 to determine processing and routing necessary for the call. The operating element 10 sends a response message 62 containing routing and processing instructions to the originating switch node 32 or if the instructions are on the service control point as described in connection with FIG. Instruct to retrieve the command from the service control point 33 identified in the response message 62. The originating exchange node 32 correlates the response message with the request message 61 that it receives from the signal transfer point 34. The originating exchange node 32 then forwards the call on its own or requests detailed instructions from the service control point 33. It should be noted that the originating switch node 32 controls the rest of the set up call according to the previous description, but no information packet is formed in the operating element 10. Further, in this embodiment, development is required to correlate the request message 61 with the response message 62 in the exchange node on the transmission side of the network.

  The call detail recording program 52 shown in FIG. 5 creates one call detail record for each billable call established by the telecommunications network. The call detail record contains information captured in an information packet containing a request message, a response message (from the operating element and, if used, from the service control point), a reply message and a release message. It is out. Because of the time stamps in each information packet, the operating element 10 can develop a daily histogram of traffic and other activity magnitudes at each switch node and each service control point. This data can be used as a source of information for planning future growth of the network.

  In addition, the operating element 10 can support an application (not shown) that collects data for a customer, eg, a customer with a number of 800 or 900, and information on the origin of the call as a function of time of day, day of the week, etc. Alternatively, data such as call volume information can be presented, or data regarding calls that were intended but did not reach the customer's destination directly via their own computer can be provided. The operating element 10 also recognizes the state when a customer with a specific 800 or 900 number is processing the maximum possible number of simultaneous calls and includes a request message for additional calls. A message is sent to the originating exchange node requesting that the pre-recorded voice message be sent to the caller, requesting the caller to retry later when an incoming information packet is received. Can send. In this way, calls that would otherwise encounter a busy signal at the destination are stopped at the originating exchange node so that congestion does not occur in the rest of the network.

  Phone call abuse or stalking patterns are detected by the stoker identification service 55 by monitoring address completion messages associated with a particular phone number.

  A fault management application 53 on the processor in the operating element 10 analyzes the messages associated with each call processed by the network to know which of the calls failed. When a call fails, the operating element 10 initiates a test call that originates and terminates in the switching and signaling subsystem 40 of the operating element 10 and is the same network element (Fig. (Not shown).

  The next call flow shows how an error in the routing table of the signal transfer point due to data corruption is detected and corrected by the operating element. Referring to FIG. 9, the originating exchange node 32 receives a request message 61 from the local exchange carrier 31 serving the caller, verifies the message, adds appropriate transaction information, and sends an information packet 200. Forming and including in the error code field a signal indicating whether an error has been detected in the verification process. Next, the originating exchange node 32 sends an information packet 200 to the operating element 10.

  The fault management application (shown in FIG. 5) in the operating element 10 checks the error code field in the information packet 200 associated with the request message 61 to know if the call failed. Assuming that the call did not fail, and assuming that the operating element 10 could forward the call on its own as previously described, the originating switch node 32 is the signal transfer point. Estimate that 34 forwards the request to the appropriate terminating switch node 35 and sends a request message 61 to the terminating switch node 35 via signal transfer point 32. However, if the routing table of the signaling transfer point 34 is corrupted, the request message 61 will be sent to the wrong terminating switch node 36. Since the intended end switch 35 node did not receive the request message 61, it does not forward the address complete message 63, reply message (not shown) or release message (not shown) to the originating switch node 32. . The originating exchange node 32 times out and sends a release message 65 to the exchange 31 of the local exchange carrier.

  The originating exchange node 32 appends the transaction information to its release message 65, includes an entry in the error code field to indicate that a time-out error has occurred, and displays the resulting information packet 204. Transfer to the operating element 10. The fault management application checks the error code field to know that the call failed.

  As shown in FIG. 10, the operating element 10 automatically creates and issues a new request message 61 based on the contents of the information packet (shown in FIG. 9) associated with the failed call. The test call is controlled by the same originating exchange node 32 that previously sent the message indicating the call failure, and completed by returning to the operating element 10 via the exchange and signaling subsystem 40. To do.

  Upon receipt of the call request message 61, the originating exchange node 32 sends an information packet 200 to the operating element 10 to request processing and routing instructions for the call. The operating element 10 forwards the response message 62 to the switch 32, indicating that the call is a test call and how to handle it, thereby duplicating the call setup process for the failed call.

  After receiving the response message 62 from the operating element 10, the originating exchange node 32 forms an information packet 201 from the response message 62 and transmits the packet 201 to the operating element 10. The operating element 10 can verify that the correct instruction from 10 has been received.

  When owning the routing and processing instructions for the test call from the operating element 10, the originating exchange node 32 sends a request message 61 to the terminating exchange node 35 via the signal transfer point 34, in the message. A signal indicating that the call is a test call is embedded. The test call signal mandates that each switch and service control point through which the call passes send a copy of each message it sends or receives to the operating element 10 as an information packet. As before, the request message 61 is sent to the wrong terminating switch node 36 because the routing table of the signaling transfer point 34 has been corrupted. Since the intended end switch node 35 did not receive the request message 61, it does not forward the address complete message, reply message or release message to the originating switch node 32. The originating exchange node 32 times out.

  However, at this time, the terminal switch node 36 that has received the misdelivered request message 61 also sends the information packet 206 to the operation element 10 because of the parameters embedded in the request message 61 received from the switchboard node 32 on the originating side. In the error code field indicating that you received a misdelivered message.

  The originating switch node 32 releases the test call due to a time-out error, adds transaction information to its release message 65, and in the error code field indicating that a time-out error has occurred. Include the entry and forward the information packet 204 to the operating element 10.

  The operating element 10 examines the information packets 200, 201 and 204 from the originating exchange node and the information packet 206 from the terminating exchange node 36 receiving the misdelivered message, and the signal transfer point 34 Know that an error has occurred. The operating element 10 uses a network map table (shown in FIGS. 2 and 5) to know which signal transfer point 34 is serving the terminating switch node 35, 36, respectively, and the signaling signal that caused the error. It communicates with point 34 by error correction message 208 and modifies its routing table to correct the error. A new test call is then issued to verify the correct call routing.

  The test call causes the operating element to be received and transmitted by each network element through which the test call has passed, as well as receiving a selection message sent to the operating element by the originating exchange node when the original call is finalized. You can receive all messages completely. In this way, the operating element is whether the problem that caused the call to fail is within the network element associated with the telecommunications system serviced by the operating element, or the problem is external to the system. For example, local exchange carriers, private branch exchanges, or competitors' access provider exchanges. If it is found that the problem is internal to the telecommunication system serviced by the operating element, the problem can be corrected in real time by the operating element. The operating element automatically logs a corrected trouble report and alerts the telecommunications system if further manual action is required for repair.

  If the type of test call is different, it is indicated by the test call prefix. For example, a customer can inquire about the cost of a particular call and request a check on the amount charged. As shown in FIG. 11, the case worker 45 can initiate a test call from the exchange and signaling subsystem 40 to replicate the call in question, resulting in delinquency from the service bill issuer. Along with the amount charged, the message received from each network element through which the call has passed can be used to indicate to the customer that the call has been correctly routed and charged (not shown). The message flow mechanism for a typical call set up in the network was previously described in connection with FIG. The operating element 10 is an information packet associated with a selected message from the originating exchange node 32, such as a request message 61, a request message 61, a response message 62, an address completion message 63, a reply message 64 and a release message 65. 200-204 is received. Further, as described with respect to FIG. 10, a test call causes the operating element 10 to only receive selected information packets 200-204 that are sent to the operating element 10 by the originating switch node 32 upon confirmation of the normal call. Rather than receive, all additional information packets 210-229 associated with the received and transmitted messages from each network element 32, 33 and 35 that the test call has passed are fully received.

  In another example, referring to FIG. 2, an automatic test call originating from the operating element 10 and terminating at the operating element 10 is made by a computer test device 46 at each end to route the path between the switch nodes 32. Transmission characteristics 47 can be checked, thereby performing quality assurance tests without human intervention.

  Referring again to FIG. 5, the post-dial delay time measurement program 58 in the operating element 10 operates in cooperation with the fault management application 53 and the information packet database 12 to call the dialed telephone number of the called party. The side measures the time it takes to hear the return ring sound indicating that the called phone is ringing.

  As previously described in connection with FIG. 4, each information packet 80 forwarded from the network element to the operating element indicates when the network element received the message contained in the information packet. A time stamp 92 is included. As shown in FIG. 12 (showing the partial call setup of the message flow previously described in connection with FIG. 3), the first information packet 200 received by the operating element 10 is the request message 61. The operating element 10 records the value of the time stamp included in the information packet 200. To determine the first component of the delay time after dialing, the operating element 10 determines the value of the time stamp between the information packet 202 containing the address completion message 63 and the information packet 200 containing the request message 61. Record the difference.

  Other components of delay time after dialing include the following. (I) the time until the request message 61 is transmitted from the caller local exchange carrier switch 31 to the caller exchange node 32; (ii) the local exchange carrier switch 31 processes and sends the request message 61; (Iii) the time it takes for the address completion message 63 to pass from the originating exchange node 32 to the local exchange carrier exchange 31 on the calling side, (iv) ) The time taken for the exchange 31 of the local exchange carrier to start sending ringback tones to the caller after receiving the address complete message 63, (v) one message, eg, request message 61 or address complete message 63 is associated with the local exchange carrier switch 31 on the calling side Time it takes to pass through the eclipse signal transfer point (not shown).

  As shown in FIG. 13 and previously described in connection with FIG. 11, the test call made by the operating element 10 is the network element 32, 33 and 35 and the local exchange carrier 31 through which the particular call has passed. All of the information packets 200-219 and 229-231 that can be used to calculate the delay time (i)-(v) between are fully provided. To calculate the delay time (i), when the test call is started, the operating element 10 records the time. When receiving the information packet 200 from the originating exchange node 32 containing the request message 61, the operating element 10 receives the request message 61 by the originating exchange node 32 and the time when the test call is activated. The difference between the time stamp value in the information packet 200 representing the determined time is calculated. This difference can be normalized by some procedure. The procedure is that the actual distance between the calling local exchange carrier switch (shown in FIG. 2) and the originating switch node 32 is shorter than the distance between the operating element 10 and the originating switch node 32. Consider the difference in propagation time, which depends on whether it is long or long.

  A similar delay component (iii) associated with the address completion message is also determined from the test call data, which is equal to the time stamp difference contained in the information packets 202 and 231 respectively. This delay time component is normalized in the same manner as component (i).

  The component (ii) of the delay time is recorded by the operating element 10 by recording the time when the dialed number is received by the operating element 10 and the time when the request message is sent by the operating element for the test call. Calculated. In this case, the operating element acts as a proxy for the local exchange carrier switch. The component (iv) of the delay time is also calculated by the operating element 10 by recording the reception time of the address completion message and the start time of the ringback tone in the test call. The delay time component (v) is stored in the operation element 10 in advance. Components (ii), (iv), and (v) are added to components (i) and (iii).

  The values of the delay time components (i)-(v) are added to the first component of the delay time after dialing to obtain the total value of the delay time after dialing for the call. This represents the round trip propagation delay time measured from the exchange on the caller's local exchange carrier.

  If necessary, the delay value representing the local loop, i.e., the call passes between the calling / calling telephone and the calling / calling local exchange carrier switch. Can be added to the total delay time after dialing (which is a function of the distance from the switch of the serving local exchange carrier to the telephone).

  A second method for calculating the post-dial delay associated with a single call involves monitoring by two call operating elements traveling in the opposite direction between the same network nodes. For example, as shown in FIG. 14, the first monitored call 101 originates in New York and terminates in San Francisco. The originating switch node 102 for the first call is in or near New York City and the terminating switch node 103 for the first call is in or near San Francisco. Thus, the monitored second call 110 originates from San Francisco and terminates in New York. Therefore, the exchange node 103 on the originating side of the second call will be in San Francisco, and the terminating exchange node will be in New York.

  The first component of the delay time after dialing is calculated by the operating element 10 for the first call to be monitored. This records the time stamp value difference between the information packet 104 containing the address complete message 63a (received from the switch node 102 in New York) and the information packet 105 containing the request message 61a, This difference is made by adding the time it takes for the address completion message 63a to pass through the switch node 102 (the value of this transfer time is calculated from the data for the test call). Thus, the first component of the delay time after dialing includes the following times in addition to the transmission and processing delay times associated with the request 61a and address complete 63a messages in New York. (1) the actual time it takes for the address complete message 63a to be transmitted from the local exchange carrier switch 106 in San Francisco to the switch node 103 in San Francisco; (2) the number of the called party on the local exchange carrier switch 106; Is the processing time required to know that the callee side is free and (3) the start time of the ringback signal for the callee side and the address completion message 63a to the exchange node 103 in San Francisco (4) The time it takes for the address complete message to be transmitted from the local exchange carrier switch 106 in San Francisco to the switch node 103 in San Francisco.

  Similarly, the second component of the delay time after dialing is calculated by the operating element 10 for the second call 110 to be monitored. This is by recording the time stamp value difference between the information packet 109 containing the address complete message 63b and the information packet 108 containing the request message 61b received from the switch node 103 in San Francisco. Done. The second component of the delay time after dialing is the address complete together with the components (2)-(4) of the delay time similar to those described in relation to the first component of the delay time after dialing. It includes the actual time it takes for message 63b to be transmitted from local exchange carrier switch 107 in New York to switch node 103 in San Francisco.

  By adding the first component of the delay time to the second component of the delay time, the delay time between the switch nodes 102, 103 in New York and San Francisco for the request message 61a, b and the address completion message 63a, b It will be counted twice. To correct for this, a test call (not shown) made by the operating element 10 can be used to calculate a delay value for a call transmitted between New York and San Francisco.

  This delay time is the time it takes for the request message to pass through the switch node 103, the time it takes for the request message to be transmitted from the San Francisco switch node 103 to the New York switch node 102, and the message passes through the switch node 102. The total time that the address completion message is transmitted from the New York switch node 102 to the San Francisco switch node 103 and transmitted over the switch node 103. Consists of This delay time value needs to be subtracted from the sum of the first and second components of the delay time to obtain the post-dial delay time associated with a single call passing between New York and San Francisco. .

  The processing time required for the local exchange carrier exchanges 106 and 107 to receive the dialed digits and send the request messages 61a and b to the network exchanges 102 and 103, and the request messages 61a and b from the network exchanges 102 and 103 are The final adjustment is made by taking into account the difference between the time it takes to receive and send the address complete message 63a, b to the network switch 102,103 and start sending the ringback tone to the called party. This is performed for the delay time value after dialing. A value representing the difference between the processing time of the address completion message 63a, b in each local exchange carrier 106,107 and the processing time of the request message 61a, b (obtained from the switch manufacturer of the local exchange carrier) It is maintained in the database (not shown) by the operating element 10. Using the value for each local exchange carrier 106, 107 involved in the call, the operating element 10 can adjust the final value of the delay time after dialing.

  If necessary, the delay value representing the local loop, i.e., the call proceeds between the caller / caller's telephone and the caller / caller's local exchange carrier switch. Can be added to the total delay time after dialing (a function of the distance from the switch on the serving local exchange carrier to the telephone).

  All post-dial measurements associated with all or a subset of calls traversing the network are stored in different network elements and in a database maintained by the operating element to obtain a history of delays in different time periods be able to. The delay time database can be used for congestion management, long distance network planning, and clock monitoring and synchronization (discussed in more detail below).

  Referring to FIG. 5, in accordance with a preferred embodiment of the present invention, the operating element 10 also supports a network time monitoring and synchronization application 59. As shown in FIG. 15, each network element 30 involved in call processing and routing needs to be synchronized to a high precision centralized master clock 41 maintained by the operating element 10. A local clock 49 is provided. The central master clock 41 may be an atomic (cesium) clock with a variation of less than 10 microseconds per year, synchronized to a national time source.

  The operation element 10 initializes the clock in the network element 30 and can update the value of the clock 49 in the network element when the clock is out of synchronization with the master clock 41.

  In order to initialize a new clock, the network element 30 sends a network synchronization time request message 42 to the operating element 10. The operating element 10 obtains a calculated and normalized delay time value associated with the propagation from the operating element 10 to the network element 30 requesting synchronization from the delay time database and the delay time. Is added to the current value of the master clock 41, and the resulting value is sent to the network element 30 by the network synchronization time providing message 43. The network element 30 initializes its own local clock 40 and sends back a network synchronization time reception confirmation message 44 including the initialized value of the clock 49 to the operation element 10.

  In order to verify or update the value of the network element clock 49, the operating element 10 periodically sends a time monitoring request message 45 to the network element 30. In response, the network element 30 sends a time monitoring confirmation message 46 to the operating element 10. Among these messages are the message processing delay value associated with receiving the incoming message at the network element 30 to the value of the local clock 49 and the network element 30 determined by the network element 30 itself. It includes a value added with the value of the processing delay time associated with the transmission of the message. The message processing delay time in the network element 30 is defined as a value at which the message input and processing delay time exceeds the output processing delay time in the element 30.

  The operating element 10 receives a confirmation message 46 from the network element 30. The message contains the local clock value 49 in the network element 30. The operating element 10 calculates the delay time associated with sending a message to the network element, called the forward delay time, three times in succession (to obtain an average value) using the following equation:

  Forward delay time = (round-trip delay time−network element message processing time) / 2. This delay time is symmetric and it is assumed that the forward average delay time is equal to the reverse average delay time. The received clock value + average backward delay time value is compared with the time 41 of the master clock at the time the time monitoring confirmation message was received. If the resulting value is significantly different from the correct time of the master clock 41, the operating element 10 sends a time change request message 47 to that network element. This message contains the exact time value by the master clock + the previously calculated forward delay time + the message processing delay time associated with the network element. Next, the network element updates the time of the local clock 49 and sends a new time reception confirmation message 48 to the operating element. Forward delay time measurements can be added to the delay time database.

  In order to prevent the time monitoring request message from interfering with the operation of the network, the operating element 10 can monitor the status of the local clock 49 of the network element each time an incoming call is received. For each call traversing the network, the operating element 10 represents the point in time when a particular message (eg, request message, response message, address completion message, reply message and release message) is received by the originating switch node. An information packet is received from the originating exchange node that includes a time stamp. The operating element records the time when the information packet was received. Look up the forward delay value from the delay time database for the particular originating exchange node that is sending the information packet, and order the time stamp value contained in the information packet. By adding the direction delay time and comparing it with the time of receipt of the information packet according to the master clock 41, the operating element 10 sends a time monitoring request message 45 to each network element on a continuous basis. None, it can inform whether the local clock 30 is synchronized to the master clock 41.

  When the service control point embeds a time stamp value in a message sent from the service control point to the originating exchange node, the operation element can obtain the time stamp value from the service control point. Thus, when an operating element receives an information packet from an originating switch node that includes a time stamp embedded in the transmitted message, the information packet has two time stamp values. Contains. The first time stamp value is in the transaction information section of the packet and represents the time at which the originating exchange node received the message contained in the packet. The second time stamp value is embedded in the message itself and represents the local time when the service control point sent the message to the originating exchange node.

Claims (3)

A method for determining a passage path for a call passing through a plurality of interconnected network elements in a communication network, comprising:
Detecting a request message by the first network element indicating that the call has been initiated;
Copying the request message;
Forwarding the request message to a subsequent network element;
Appending a set of transaction information to the request message detected and copied by the first network element, the transaction information and the copied request message forming one information packet;
Including in the information packet identification information indicating that a second network element is seeking instructions for processing and routing the call;
Transferring the information packet from the first network element to a communication unit in communication with the first network element;
Determining the necessary processing and routing of the call based on the contents of the transferred information packet using a database in communication with the communication unit;
Sending a message from the communication unit to the second network element indicating a method of handling and routing the call; and the request message and the call sent by the second network element. A method comprising the steps of: correlating messages indicating processing and routing instructions to   2. The method of claim 1, wherein the second network element comprises an originating network element responsible for controlling the call setup. The method of claim 2, further comprising:
Sending a message generated from each of a plurality of interconnected network elements passed during the call setup to the originating network element;
Copying the sent message;
Adding a set of transaction information to the copied message, such that the transaction information and the copied message form an information packet;
Transferring the information packet from the originating network element to the communication unit;
Correlating an information packet associated with a request message forwarded from the first network element with an information packet associated with a message forwarded from the originating network element; and a particular call Storing information packets associated with the database in a database so that a set of data is formed for each call used to support the function of the communication network.

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