KR19990038012A - How to prevent incorrect access to voicemail service for call transfer numbers - Google Patents

Abstract

Voice mailbox service misconnection prevention method of the call transfer number according to the present invention,

Upon receiving a location request message in the home subscriber registration system, checking whether the current call is a call that has been diverted more than once and terminating the program if it is not a call; Checking whether the call transfer service should be provided immediately if the call was diverted; If the call transfer service is provided in step B, checking whether the call transfer is made to the voice mailbox service, and ending the program if it is not switched to the voice mailbox service; If it is switched to the voice mail service, blocking the voice mail service access and terminating the program; If the call transfer service is not provided in step B, checking whether it is necessary to access the voice mailbox service when a call reset request is made, and if not, terminating the program; If it is necessary to connect to the voice mailbox service, generating a context and checking whether it is used or not and generating [LegInfo]; Generating a context and a context valid time if the context is to be created and used; Generating a [LegInfo] and checking whether it is to be used; Generating [LegInfo] if generating and using [LegInfo]; Checking whether the context valid time has been exceeded in the presence of the context; If the valid time of the context has been exceeded in step J, destroying the context; if [LegInfo] has been generated, destroying [LegInfo] and terminating the program; Checking whether a switch number request message has been received, and if not, returning to step J; If a forwarding number request message is received, check whether the received forwarding number request is for the current call, or if the forwarding number request is for the current call in step M and step M returning to step J, preventing the VMS transition Thereafter, the method includes the step N of destroying the context in the presence of the context, extinguishing [LegInfo] in the presence of the [LegInfo], and terminating the program.

It is possible to prevent the incoming call home subscriber registration system from being incorrectly connected to the voice mailbox service of the third party through the above process.

Description

How to prevent misconnection of voice mailbox service of call forwarding number

The present invention relates to a method for preventing a voice mail service (VMS) misconnection of a call forward number, and more particularly, a method for providing a voice mail service switching service using an IS-41-C in a mobile communication system. The present invention relates to a method for blocking a voice mail service misconnection in which an sender leaves a message to a voice mailbox of a third party subscriber that has been switched, in an IS-41-C MAP.

A mobile communication system is a system for providing various services to a mobile station (MS) wirelessly, and has a base station for each cell, which is an allocated area, to transmit wireless data to the mobile terminal in the corresponding area.

Mobile communication systems, such as Code Division Multiple Access (CDMA) cellular and personal communication services (PCS), serve many mobile terminals (mobile stations) moving within a certain area. Base Station Transceiver Subsystem (BTS), Base Station Controller (BSC), Base Station Manager System (BSM) to manage and manage several base station controllers (Mobile Switching Center (MSC)) And a Home Location Register (HLR).

The area serviced by each base station is called a cell and is generally divided into one omni-cell or three sector cells. This cell expands to the base station area, base station controller area, and switching center service area in order. As described above, a communication system using one cell as a unit is called a cellular system.

The mobile communication system configured as described above provides a service such as a call transfer or a voice mailbox for the mobile terminal. Such subscriber service is registered for each subscriber in the home subscriber registration system.

The home subscriber registration system includes all subscriber information of the wireless communication system, that is, an electronic serial number, directory number, international mobile station identification, and user profiles. ) Is a functional unit used to manage mobile subscribers by preserving the current location and the like.

In the communication system configured as described above, the call is set up by the originating exchange system by analyzing the message.

The destination exchange system then uses the information received in routing to determine if the current call should be forwarded to the voice mailbox service, and if so, connects the calling voice mailbox service at the destination exchange system.

In this case, the destination exchange system cannot tell the calling exchange whether the call was connected to the voicemail service or to a terminal or other functional entity. Therefore, in the originating exchange system, it was not possible to know whether the diverted call was connected to the voice mailbox service of the subscriber other than the subscriber who requested the first connection.

For example, the first or more call transfer may be transferred to a third party divert, and then transferred to a voice mailbox service by a third party's supplementary service.

That is, when the call to be received to subscriber 1 is transferred to subscriber 2, if subscriber 2 is subscribed to the voice mailbox service, the call to be received to subscriber 1 may be incorrectly connected to subscriber 2's voice mailbox service.

In this case, the originating exchange system should detect that the incoming exchange system is a switched call without knowing that the transfer call is connected to the voice mailbox service, and thus prevent the misconnection.

However, if the subscriber is provided with a roaming service in motion, the user may move to another area. In this case, the subscriber is provided with a service from a serving system of a different environment from the home system.

In this case, an exchange system providing a service in a roaming region may not detect a voice mail service misconnection.

Therefore, a problem occurs that a third party voice mailbox service misconnection occurs. This misconnection occurs because the service was provided by the exchange system.

The exchange system providing the service may change from time to time as the subscriber moves. However, since the home subscriber registration system of the user is not changed by the subscriber's movement, the service needs to be provided by the HLR in order to provide a consistent service even in a roaming environment.

Accordingly, the present invention was devised to solve the above problems, so that a service which prevents a misdirected call to a third party voice mailbox service can be provided uniformly without being affected by roaming of the user. In a system that conforms to the IS-41-C standard in a mobile communication network and prevents the call transfer from being incorrectly connected to a third party voice mailbox service without regard to the roaming environment of the user, in all systems that satisfy the standard, The purpose is to provide.

1 is a flowchart illustrating a method for preventing a third party voice mail service misconnection according to the present invention.

2 is a format of [LegInfo] according to the present invention.

3 is a format of a context according to the present invention.

4 is a message flow diagram illustrating a method for preventing a false access to voice mail service of a switched call according to the present invention.

5 is a message flow diagram illustrating a method for preventing a false access to voice mail service upon redirection of a divert call according to the present invention.

One preferred embodiment of the present invention created to achieve the above object,

Upon receiving a location request message in the home subscriber registration system, checking whether the current call is a call that has been diverted more than once and terminating the program if it is not a call; Checking whether the call transfer service should be provided immediately if the call was diverted; If the call transfer service is provided in step B, checking whether the call transfer is made to the voice mailbox service, and ending the program if it is not switched to the voice mailbox service; If it is switched to the voice mail service, blocking the voice mail service access and terminating the program; If the call transfer service is not provided in step B, checking whether it is necessary to access the voice mailbox service when a call reset request is made, and if not, terminating the program; If it is necessary to connect to the voice mailbox service, generating a context and checking whether it is used or not and generating [LegInfo]; Generating a context and a context valid time if the context is to be created and used; Generating a [LegInfo] and checking whether it is to be used; Generating [LegInfo] if generating and using [LegInfo]; Checking whether the context valid time has been exceeded in the presence of the context; If the valid time of the context has been exceeded in step J, destroying the context; if [LegInfo] has been generated, destroying [LegInfo] and terminating the program; Checking whether a switch number request message has been received, and if not, returning to step J; If a forwarding number request message is received, check whether the received forwarding number request is for the current call, or if the forwarding number request is for the current call in step M and step M returning to step J, preventing the VMS transition Thereafter, the step of destroying the context in the presence of the context, destroying the [LegInfo] in the presence of [LegInfo], and then terminating the program.

In the present invention, the voice mailbox service context generated in step G may be used for the same purpose as the field indicating the context index for finding the current context from many voice mail service contexts being held at the same time. A BillingID field used to distinguish the original call; It is preferable to optionally include a field indicating the type of voice mailbox service context and a field indicating user information such as MIN or ESN.

If you use a context, we recommend that you use the BillingID within the Voice Mail Service context to retrieve that Voice Mail service context.

It is preferable to search for the corresponding voice mail service context using [LegInfo] set by the home subscriber registration system.

[LegInfo] is composed of a field indicating a leg type; It is desirable to be able to optionally include a preliminarily prepared field and a field representing a context index.

In addition, a second preferred embodiment of the method for preventing a voice mail service misconnection of a call transfer number according to the present invention,

A first step of dialing, by the mobile terminal, the telephone number of the other party to be called by the calling switching center system; A second step of analyzing the telephone number generated in the above step and requesting call establishment to the registered home subscriber registration system of the subscriber having the telephone number; The terminating home subscriber registration system includes: a third step of requesting routing of a called party having a corresponding telephone number to determine a route; The originating switching center system attempts to set up the call using the determined path; The destination switching center system connected with the original called party includes: a fifth step of reporting to the calling switching center system why the called party cannot receive a call; A sixth step of the calling switching center system requesting the switching number to the called home subscriber registration system in order to determine whether the corresponding subscriber has the call forwarding number; A seventh step in which, if there is a forwarding number, the called home subscriber registration system answers the forwarding number and call leg information for call forwarding to the calling switching center system; An eighth step of the originating exchange system reporting the completion of the call reset to the original destination exchange system; The originating switching center system further comprises a ninth step of requesting call establishment to a new destination home subscriber registration system using the new forwarding number obtained in the seventh step; A tenth step of analyzing the call in the incoming home subscriber registration system; If the call is a transferred call, the incoming home subscriber registration system sends an access denied message to the calling switching center system without connecting the location-requested call to the voice mail service; And a twelfth step, wherein the originating switching center system reports to the originating subscriber that the call connection has failed.

In the second embodiment of the present invention, it is preferable to use [LegInfo] to determine whether the current call connection is a voice mail service misconnection of the switched call,

It is desirable to use the BillingID in the voicemail service context to determine if the current call connection is a voicemail service misconnection of the diverted call.

In addition, a third preferred embodiment of the method for preventing a voice mail service misconnection of a call forwarding number according to the present invention,

A first step of dialing, by the mobile terminal, the telephone number of the other party to be called by the calling switching center system; A second step of analyzing the telephone number generated in the first step and requesting call establishment to the registered home subscriber registration system of the subscriber having the telephone number; The terminating home subscriber registration system includes: a third step of requesting routing of a called party having a corresponding telephone number to determine a route; The originating switching center system attempts to set up the call using the determined path; The destination switching center system connected with the original called party includes: a fifth step of reporting to the calling switching center system why the called party cannot receive a call; A sixth step of requesting a forwarding number to a called home subscriber registration system in order to determine whether the calling party has a call forwarding number; A seventh step of, if there is a forwarding number, the called home subscriber registration system to report the forwarding number and call leg information for call forwarding to the calling switching center system; An originating exchange system reporting the completion of call reset to the original destination exchange system; The originating switching center system further comprises a ninth step of requesting setting up a call to a new destination home subscriber registration system using the new forwarding number obtained in the seventh step; A tenth step in which the new destination home subscriber registration system requests routing and determines a path from a called party having a new switching number; An eleventh step in which the new incoming home subscriber registration system knows from the message received from the originating switching center system that the current call is a reset call rather than the first call, creates a context to prevent misconnection of the voice mailbox service, and then starts a timer. ; A twelfth step, wherein the new incoming home subscriber registration system responds to the calling switching center system; The originating switching center system may further include: a thirteenth step of attempting to set up a call to the connected path in the twelfth step; Step 14, if the called party does not answer the call or otherwise fails to set up the call, the called side exchange system reports the call setup failure reason to the calling side exchange system; The calling party exchange system, the fifteenth step of inquiring whether there is a conversion number registered with the new called home subscriber registration system in which the new called subscriber is registered; A sixteenth step of the home subscriber registration system finding a voice mail service context if the timer generated in the eleventh step is still valid; If there is a context and this call is to be diverted to voice mailbox service, the called home subscriber registration system sends an access denied message to the calling switching center system without connecting the call to the voice mailbox service; And the eighteenth step, wherein the originating switching center system reports to the originating subscriber that the call connection has failed.

In a third embodiment of the present invention,

It is preferable to use [LegInfo] to determine whether the current call connection is a voice mail service misconnection of the transferred call.

It is desirable to use the BillingID in the voicemail service context to determine if the current call connection is a voicemail service misconnection of the diverted call.

An object of the present invention is to implement a third party voice mail service misconnection prevention function of a call transfer call in a home subscriber registration system.

To prevent misconnections, context management of calls is required. By default, the RedirectingNumberDigits parameter should be used to recognize call transfers and to set up a context to prevent misconnections.

This context is managed by the operator and can contain information such as the subscriber's mobile identification number (MIN) or the electronic serial number (ESN) of the terminal and can be used to manage the subscriber's information.

Protection against misconnection by third party voicemail service of diverted call must meet the following conditions.

① RedirectionNumberDigits should be included in the position request message of the redirected call.

② If call communication fails after call establishment, [BillingID] or [LegInfo] (LegInformation) is included in TransferToNumber (TTN) request.

Both of the above conditions can be established as long as the IS-41-C MAP is observed. If the above conditions are satisfied, the procedure for preventing the diverted call from connecting to the third-party voice mail service is as follows.

If the location request message includes RedirectionNumberDigits and the call needs to be diverted to voicemail service, the redirected call is being misconnected to a third party voicemail service.

If it is necessary to block misconnection of call as above, returnResult of location request message with AccessDeniedReason set appropriately.

If the call is switched to the voice mailbox service when the call fails when the call is not transferred and the call is normally received, the context is generated, the timer VACT is started, and the LegInformation is generated.

When the timer VACT expires, the timer and context are destroyed.

When the call request message is received, if the call is redirected to the voice mail service by checking the context or [LegInfo], the call is determined to be failed, and the AccessDeniedReason is appropriately set and the ReturnResult is transmitted.

If the timer has not yet expired, the context is destroyed.

Misconnections to third party voicemail services may occur upon location request and conversion number request.

In this case, since the call is started at the time of the location request, the context management is not necessary. However, the context can be used to correlate with the request for the location that occurred previously.

If the context is not used, [LegInfo] is analyzed to prevent misconnection by only [LegInfo] when this caller ID request does not create a voice mail service context, and [BillingID] without [LegInfo] if the context exists. You can also prevent incorrect connections.

The originating exchange system that receives the [TLDN] attempts to set up the call, and if the call is not made normally, i.e. when there is no answer, no page response, call collision, etc., the originating exchange system requests a call redirection from the destination exchange system. Or generate an internal number request message.

At this time, the exchange system transmits to the home subscriber registration system including [BillingID] in the transfer number request message to be transmitted, if possible. It also includes [LegInfo] if it receives a [LegInfo] in the call reset request or location request response.

The home subscriber registration system analyzes the LegType of [LegInfo] or [BillingID] of the transfer number and blocks access to the voice mailbox service system.

The HLR transmits the change number request response by setting an appropriate value in the AccessDeniedReason, for example Termination Denied.

1 is a flowchart illustrating a method for preventing a wrong access of a voice mail service of a third party according to the present invention.

In step A, the HLR checks whether the current call has been diverted more than once from the received location request message.

To check, check if the location request message contains RedirectionNumberDigits. This is because the IS-41-C system includes RedirectionNumberDigits for the transferred call.

If the call is not diverted, the third party voice mail service misconnection prevention program is terminated.

In step B, if the called party has an active call transfer service and a call transfer is made immediately by the active call transfer and the state of the called terminal and other additional states, go to step C. Otherwise go to step E.

In step C, if the call transfer is performed by the voice mailbox service, the call is connected to a third party voice mailbox service. In step D, the voice mail service is disconnected and the program is terminated.

If the call is not transferred to the voice mailbox service, this is also the case because the transferred call is transferred to a place other than the voice mailbox service, so the program is also terminated.

Step E is a case in which the called party attempts to set up a call normally. In step E, it is checked if the call should be connected to the voice mailbox service when the call is reset.

If a call redirect occurs due to an additional service of the called party, and the call is connected to the voice mailbox service when the call is reset, this is a voice mail service misconnection.

Therefore, when accessing the voice mailbox service, the flow moves to step F to block call resetting. Quit the program unless you're connecting to voicemail.

In step F, it is checked whether the context should be used to prevent a third party from connecting to the voice mailbox service upon call resetting.

If you need to use a context, go to Step G to create a context and context timer, and create a [LegInfo] related to preventing false access.

The context and the context timer are not necessarily required and can be used selectively. If you don't create a context, use [LegInfo].

Therefore, in step H, it is checked whether [LegInfo] is used.

[LegInfo] makes it possible to determine whether the current call requires a voicemail service misconnection prevention function when the call is reset.

2 illustrates the format of [LegInfo] according to the present invention.

As shown, a leg type of one byte (LegType); A reserved area of 1 byte; Contains an index of two bytes. The leg type records the type of the current [LegInfo].

If no context is used, step G and step H are skipped and moved to step J.

If you are using a context, go to step J to check if the validity timer of the context has expired. If it is terminated, the context is lost in step L and the program ends.

If the validity timer has not expired, go to step K, and check if a switch number request for call resetting has been received.

If there is a received TTN request, go to step M to see if the received TTN request is for the current call.

Since the redirection number request includes [BillingID] and [LegInfo], these two parameters are used to find the context. If no context is used, look for the LegType of [LegInfo].

3 illustrates the format of a context according to the present invention.

As shown, an index of two bytes; A context type of one byte; 7 bytes of Billing ID; It consists of actual information parts.

The format of [LegInfo] is as shown in FIG. 2, which indicates that a false call prevention function to the voice mailbox service is set for the current call.

If the context is found, this call forwarding number will obviously misconnect to the third party voicemail service. If not found or if [LegInfo] is not for the current call with the misconnection prevention function set back, go back to step J.

In step N, AccessDeniedReason is appropriately set without returning the conversion number to be connected to the voice mail service, and the ReturnResult is returned to prevent the voice mail service from accessing the voice mail service.

If you used context, destroy the context and validity timers and exit the program. If [LegInfo] is used, [LegInfo] is destroyed.

4 is a message flowchart illustrating a method for preventing a false access of a voice mail service of a switched call according to the present invention.

In step 101, the mobile terminal dials the telephone number of the other party to be called by the calling switching center system.

In step 102, the calling switching center system analyzes the telephone number generated in step 101, and transmits a location request message in which [DIALDGTS] is set to the called home subscriber registration system in which the subscriber having the telephone number is registered. do.

From step 103 to step 106, the called home subscriber registration system requests routing from the called party with the telephone number to determine the route.

In step 107, the originating switching center system attempts to set up the call using the determined path.

In step 109, the destination switching center system connected to the original called party sends a Redirection Request message to the calling switching center system by recording in the [REDREASON] (Redirection Reason) the reason why the called party cannot answer the call.

In step 110, the calling switching center system sends a turnover number (TTN) request message to the called home subscriber registration system to determine if the subscriber has a call forwarding number.

If there is a forwarding number, the called home subscriber registration system sets up a forwarding number request message including [LegInfo] in which the forwarding number for the call transfer and the call leg information is recorded in step 111, and responds to the calling switching center system.

In step 112, the originating exchange system reports that the current call is diverted to the original destination exchange system.

In step 113, the source switching center system sets the new transfer number obtained in step 111 to [DIALDGTS] and sends a location request message to the new destination home subscriber registration system.

The steps from step 114 to step 117 show that the prior art requires routing to the new destination switching center system. In this case, the destination switching center system, which is requested to route, determines that the connection is transferred and prevents a wrong connection.

However, in the present invention, as shown in A of FIG. 4, in the destination home subscriber registration system, [REDNUM] (Redirection Number Digits) of the location request message is analyzed to find that the call is not the first call but the reset call.

Then, in step 118, the incoming home subscriber registration system sends a forwarding number request message with appropriately set [ACCDEN] (AccessDenied) to the calling switching center system without connecting the location requested call to the voice mailbox service.

In step 119, the originating switching center system reports to the originating subscriber that the call connection has failed.

As described above, the home subscriber registration system determines whether or not the call is switched, it is possible to more effectively prevent the voice mailbox service access.

In addition, it is possible to prevent a false access of the voice mailbox service to a call transferred more than once.

In other words, when the call is not established even after attempting to set up a call after completing the connection of the path in a state in which the subscriber connected to the call can receive a call, the call is prevented from being switched to the voice mailbox service.

5 is a message flow diagram illustrating a method for preventing a false access to a voice mail service when a divert call is re-directed according to the present invention.

Referring to the drawings will be described in detail with respect to the method for preventing a voice mail service mis-access when re-switching the conversion call.

In step 201, the mobile terminal dials the telephone number of the other party to which it wants to talk to the originating switching center system.

In step 202, the calling switching center system analyzes the telephone number generated in step 201, and transmits a location request message for setting [DIALDGTS] to the called home subscriber registration system in which the subscriber having the telephone number is registered. do.

From step 202 to step 203, the called home subscriber registration system requests routing from the called party with the telephone number to determine the route.

In step 204, the originating exchange system attempts to set up the call using the determined path.

In step 205, the destination switching center system connected to the original called party sends a Redirection Request message to the calling switching center system by recording a reason in [REDREASON] (Redirection Reason) that the called party cannot answer the call.

In step 206, the calling switching center system sends a turnover number (TTN) request message to the called home subscriber registration system to determine if the subscriber has a call forwarding number.

If there is a forwarding number, the called home subscriber registration system sets up a forwarding number request message including a [LegInfo] in which the forwarding number for the call transfer and the call leg information is recorded in step 207, and responds to the calling switching center system.

In step 208, the originating switching center system reports that the current call is diverted to the original incoming home subscriber registration system.

In step 209, the source switching center system sets the new transfer number obtained in step 207 to [DIALDGTS] and sends a location request message to the new destination home subscriber registration system.

From step 210 to step 213, the new destination home subscriber registration system generates [LegInfo] 2 to request routing to the called party with the telephone number and to determine the route.

The new incoming home subscriber registration system knows from the [REDNUM] of the location request message received from the originating exchange system that the current call is a reset call rather than the first call, and creates a context to prevent a false access of the voicemail service. To drive. This timer sets the validity period of the context.

In step 214, the new incoming home subscriber registration system responds to the originating switching center system in a location request message.

In step 215, the originating switching center system attempts to set up the call with the connected path.

However, if the called party does not answer the call or otherwise fails to set up the call, the called party's exchange system sends, at step 216, the reason for the call setup failure via a call reset request message containing [LegInfo] 2 already generated. Report to side exchange system.

In step 217, the calling party exchange system sends a call request message to the new called home subscriber registration system in which the new called party is registered to search for a registered call number.

At this time, if the timer generated in step 213 is still valid, the home subscriber registration system finds the context using [LegInfo] 2 or BillingID.

If there is a context and this call is to be diverted to voice mail service, the receiving home subscriber registration system at step 218 does not divert this call to voice mail service and sets [ACCDEN] appropriately to send the Diversion Number Request message. Return to the system.

In step 219, the originating exchange system notifies the destination exchange system of the completion of resetting of the call and, in step 220, reports the connection of the call to the originating subscriber.

The present invention operating as described above,

By analyzing the [REDNUM] included in the location request message and setting the context and [LegInfo] when the first-converted call is connected to the third party voice subscriber service, the home subscriber registration system receives the call while the location request message is processed. Recognizing that call forwarding is necessary, an immediate call forwarding is performed to immediately forward the call forwarding number to the calling exchange so that the call can be forwarded. This can solve the problem of leaving.

Claims (11)

Upon receiving a location request message in the home subscriber registration system, checking whether the current call is a call that has been diverted more than once and terminating the program if it is not a call; Checking whether the call transfer service should be provided immediately if the call was diverted; If the call transfer service is provided in step B, checking whether the call transfer is made to the voice mailbox service, and ending the program if it is not switched to the voice mailbox service; If it is switched to the voice mail service, blocking the voice mail service access and terminating the program; If the call transfer service is not provided in step B, checking whether it is necessary to access the voice mailbox service when a call reset request is made, and if not, terminating the program; If it is necessary to connect to the voice mailbox service, generating a context and checking whether it is used or not and generating [LegInfo]; Generating a context and a context valid time if the context is to be created and used; Generating a [LegInfo] and checking whether it is to be used; Generating [LegInfo] if generating and using [LegInfo]; Checking whether the context valid time has been exceeded in the presence of the context; If the valid time of the context has been exceeded in step J, destroying the context; if [LegInfo] has been generated, destroying [LegInfo] and terminating the program; Checking whether a switch number request message has been received, and if not, returning to step J; If a transfer number request message is received, check whether the received transfer number request is for a current call, or step M returning to step J above and If the conversion number request for the current call in step M is for a current call, then calling N, ending the program in the presence of the context, destroying the context in the presence of [LegInfo], and then terminating the program. How to prevent misdirection of voice mail service of diverted number. The voice mailbox service context of claim 1 wherein A field indicating a context index for finding a current context from many voice mailbox service contexts being held at the same time, and a BillingID field, which can be used for the same purpose as the context index and used to distinguish the first call; A method for preventing a voice mail service misaccess of a call transfer number, which may optionally include a field indicating a type of a voice mail service context and a field indicating user information such as a MIN or an ESN. The method of claim 1, A method of preventing a voice mail service misconnection of a call transfer number that uses the BillingID within the voice mail service context to retrieve the voice mail service context when the context is used. The method of claim 1, A method for preventing a false access to a voice mail service of a call forwarding number, which retrieves a corresponding voice mail service context by using [LegInfo] set by a home subscriber registration system. 5. The method of claim 4, wherein the [LegInfo] is composed of fields indicating leg types; A method for preventing a voice mail service misaccess of a call transfer number, which may optionally include a field prepared in advance and a field indicating a context index. A first step of dialing, by the mobile terminal, the telephone number of the other party to be called by the calling switching center system; A second step of analyzing the telephone number generated in the above step and requesting call establishment to the registered home subscriber registration system of the subscriber having the telephone number; The terminating home subscriber registration system includes: a third step of requesting routing of a called party having a corresponding telephone number to determine a route; The originating switching center system attempts to set up the call using the determined path; The destination switching center system connected with the original called party includes: a fifth step of reporting to the calling switching center system why the called party cannot receive a call; A sixth step of the calling switching center system requesting the switching number to the called home subscriber registration system in order to determine whether the corresponding subscriber has the call forwarding number; A seventh step in which, if there is a forwarding number, the called home subscriber registration system answers the forwarding number and call leg information for call forwarding to the calling switching center system; An eighth step of the originating exchange system reporting the completion of the call reset to the original destination exchange system; The originating switching center system further comprises a ninth step of requesting call establishment to a new destination home subscriber registration system using the new forwarding number obtained in the seventh step; A tenth step of analyzing the call in the incoming home subscriber registration system; If the call is a transferred call, the incoming home subscriber registration system sends an access denied message to the calling switching center system without connecting the location-requested call to the voice mail service; 12. The method of claim 5, wherein the originating switching center system reports to the calling subscriber that the call has failed. 7. The method of claim 6, wherein it is determined whether or not the current call connection is a voice mailbox service misconnection of the switched call by using [LegInfo]. 7. The method of claim 6, wherein the Billing ID in the voice mail service context is used to determine whether the current call connection is a voice mail service misconnection of the transferred call. A first step of dialing, by the mobile terminal, the telephone number of the other party to be called by the calling switching center system; A second step of analyzing the telephone number generated in the first step and requesting call establishment to the registered home subscriber registration system of the subscriber having the telephone number; The terminating home subscriber registration system includes: a third step of requesting routing of a called party having a corresponding telephone number to determine a route; The originating switching center system attempts to set up the call using the determined path; The destination switching center system connected with the original called party includes: a fifth step of reporting to the calling switching center system why the called party cannot receive a call; A sixth step of requesting a forwarding number to a called home subscriber registration system in order to determine whether the calling party has a call forwarding number; A seventh step of, if there is a forwarding number, the called home subscriber registration system to report the forwarding number and call leg information for call forwarding to the calling switching center system; An originating exchange system reporting the completion of call reset to the original destination exchange system; The originating switching center system further comprises a ninth step of requesting setting up a call to a new destination home subscriber registration system using the new forwarding number obtained in the seventh step; A tenth step in which the new destination home subscriber registration system requests routing and determines a path from a called party having a new switching number; An eleventh step in which the new incoming home subscriber registration system knows from the message received from the originating switching center system that the current call is a reset call rather than the first call, creates a context to prevent misconnection of the voice mailbox service, and then starts a timer. ; A twelfth step, wherein the new incoming home subscriber registration system responds to the calling switching center system; The originating switching center system may further include: a thirteenth step of attempting to set up a call to the connected path in the twelfth step; Step 14, if the called party does not answer the call or otherwise fails to set up the call, the called side exchange system reports the call setup failure reason to the calling side exchange system; The calling party exchange system, the fifteenth step of inquiring whether there is a conversion number registered with the new called home subscriber registration system in which the new called subscriber is registered; A sixteenth step of the home subscriber registration system finding a voice mail service context if the timer generated in the eleventh step is still valid; If there is a context and this call is to be diverted to voice mailbox service, the called home subscriber registration system sends an access denied message to the calling switching center system without connecting the call to the voice mailbox service; 18. The method of claim 5, wherein the originating switching center system reports to the calling subscriber that the call has failed. 10. The method of claim 9, wherein it is determined whether or not a current call connection is a voice mailbox service misconnection of a switched call by using [LegInfo]. 10. The method of claim 9, wherein the Billing ID in the voice mail service context is used to determine whether the current call connection is a voice mail service misconnection of the transferred call.