JP4769882B2 - Media gateway control device and media gateway control method - Google Patents

Description

  The present invention relates to a technology of a media gateway control apparatus and a media gateway control method that operate on a call processing server that controls a media gateway located in a transfer network in a next generation information communication network called a Next Generation Network.

  The Next Generation Network (generally the “Next Generation Telephone Network” and “Next Generation Information Communication Network”, which provides the flexibility and economics of IP networks while ensuring the reliability and stability of conventional telephone networks. From now on, it will be referred to as “Next Generation Information Communication Network”.) To realize the environment, international standardization centered on ITU-T (International Telecommunication Union Telecommunication Standardization Sector) etc. (See Non-Patent Document 1).

  FIG. 7 is a diagram schematically showing a communication network configuration of the next generation information communication network. The communication network includes a plurality of user terminals 100 used by a user, a plurality of call processing servers 300 that control call connection requests and the like transmitted from the user terminals 100, and a transfer network based on requests from the call processing server 300. A media gateway (MG) 500 that connects internal and external terminations, and a plurality of routers (including the concept of switches) that connect the user terminal 100, the call processing server 300, and the media gateway 500 to each other so as to communicate with each other. ) 200.

  When a call to the other user is desired, a SIP (Session Initiation Protocol) signal required for establishing a call connection such as INVITE is transmitted from the user terminal 100 to another user terminal (not shown). When the result of the SIP negotiation with the user terminal is OK, a session is established between the user terminals, and a call can be made. Specifically, the SIP signal from the user terminal 100 is transmitted to the call processing server 300a, and the call processing server 300a that has received the SIP signal receives another call processing server 300b connected in the vicinity, and further. The call request is made to the user terminal of the other party via the call processing server 300c. When the user who owns the user terminal responds to the connection request, a response signal to the SIP signal is transmitted to the user terminal 100 via the call processing server 300c, the call processing server 300b, and the call processing server 300a. Is done. Thereafter, a session of media such as voice is established between the user terminal 100 and another user terminal. In this way, the user terminal 100 can communicate with a user terminal (not shown), and communicate between the user terminal 100a and the user terminal 100b (or the user terminal 100c to the user terminal 100e). It is also possible to do this. Furthermore, each of the user terminals 100a to 100e can communicate with a plurality of other user terminals (not shown). Although the dotted line shown in FIG. 7 explains the flow of the SIP signal, it is actually transmitted and received through the solid line. Further, the call processing server 300c is connected to a plurality of other transfer networks, and can exchange SIP signals with the opposite call processing server connected to each transfer network.

  Here, the result of the SIP negotiation is described in SDP (Session Description Protocol), and the media information included in the SDP includes a media type, a requested bandwidth, a direction attribute, a transfer quality class, and the like. As shown in FIG. 8, the call processing server 300 includes a call processing function unit 31 that performs call processing such as the SIP signal, and a resource management function unit that controls the media gateway 500 based on a request from the call processing function unit 31. (MGC: Media Gateway Controller, corresponding to the “media gateway control device” of the present invention) 32 and a storage unit 33 for storing various data managed by the resource management function unit 32 (hereinafter simply “memory”) It is comprised by this.

  The call processing function unit 31 determines the transfer quality class and the like from the media type and the direction attribute of the media information described above, and requests the resource management function unit 32 to control the bandwidth (band reservation reservation surrounded by a dotted line in FIG. 9). AAR (authentication and / or authorization request) signal and its reply AAA signal (authentication and / or authorization answer), Bandwidth reservation AAR (authentication and / or authorization A / A authorization signal) Authorization answer (STR) signal, STR (Session Ter) for bandwidth release Transmitting the Ination Request) signal and STA signal its reply (request for controlling the bandwidth of the Session Termination Answer), etc.). On the other hand, the resource management function unit 32 manages the route information of the transfer network and the bandwidth of each link as virtual resources and virtual paths, and the bandwidth required for the media determined by the bandwidth control request is the transfer network. When the bandwidth can be used in the virtual path, the pinhole control and policy setting for the media gateway 500 (AddRequest signal for bandwidth reservation surrounded by the dotted line in FIG. 9 and its reply) are calculated. The bandwidth is reserved, reserved, etc. by performing the AddReply signal, the Modify Request signal for securing the band and the Modify Reply signal for the reply, the Subtract Request signal for releasing the band, and the SubtractReply signal for the reply). Thereafter, the media gateway 500 newly adds, changes, or deletes a termination pair based on a request from the call processing server 300. Note that the alternate long and short dash line in FIG. 7 indicates the flow of such pinhole control.

  As shown in FIG. 10, the resource management function unit 32 of the call processing server 300 generates session information for each bandwidth securing request, and the termination ID generated and assigned by the media gateway 500 (# 1 shown in FIG. 10). And # 2) are used as termination information, and the session information and termination information are associated with each other and managed. A plurality of media (communications between user terminals shown in FIG. 9) can be linked to one session information, and the media is distinguished between the inside (BB side) and the outside (AC side) of the transfer network. These two terminations are connected and managed. The termination information includes a source IP address, a source port number, a destination IP address, a destination port number, and the like. The termination ID is formed by a character string, and most of the character string is issued by the resource management function unit 32, and the response signal as a result of the termination generation control request to the media gateway 500 is included in the media gateway 500. The character string paid out is included in an added form, and the termination ID is completed.

  As described above, the session information based on the termination information from the media gateway 500 is stored and managed in the memory, but the state of the termination information in the memory and the termination information managed by the media gateway 500 (the presence / absence of termination information) is determined. Since there is a case where they do not match, the resource management function unit 32 matches both termination information and matches the state of the termination information to match the states.

Akira Kurokawa, 1 other person, “Global Standards Frontline ETSI TISPAN NGN Standardization Trend”, April 2006, NTT Technical Journal

  However, since the session information and termination information managed by the memory of the resource management function unit 32 are updated after a response to the control request to the media gateway 500 is returned, for example, a bandwidth reservation is made as shown in FIG. When the AuditValueReply signal is received without receiving a response to the AddRequest signal (adding a new termination pair), the termination information in the matching target list generated based on the session information managed in the memory , The session managed by the resource management function unit 32 is not matched with the termination information of the media gateway acquired from the media gateway 500, and is adjusted based on a misjudgment of “MGC = none, MG = yes”. If the match to the broadcast, the cause by sending SubtractRequest signal to release the band, there is a problem that an erroneous disconnection as a result.

  For example, as shown in FIG. 12, even when the AuditValueReply signal is received in a state where no response is received to the SubtractRequest signal for releasing the band (deletion of termination), the termination information of the matching target list When the termination information of the acquired media gateway does not match, and matching is performed based on a misjudgment of “MGC = Yes, MG = No”, to match the session information managed by the resource management function unit 32 There is a problem that the call processing function unit 31 is prompted to disconnect (for example, BYE of the SIP signal) the call that has already been disconnected, resulting in an erroneous report.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a media gateway control device and a media gateway control method capable of quickly and accurately recovering the record state of a matching target list and preventing erroneous matching. And

  The present invention as set forth in claim 1 is a call processing server that stores termination information formed on the basis of presence / absence of termination pairs inside and outside the transfer network held by a media gateway located in the transfer network in a storage means. Storage means for storing a response waiting time set in advance as a time required to receive a control response to at least one control request among addition, change, and deletion of a termination pair in an operating media gateway control device; Generation means for reading out the termination information from the storage means and generating a matching target list including the termination information; and inquiry means for inquiring the media gateway about the presence or absence of the termination pair currently held by the media gateway; The question A matching unit that matches the presence / absence of a termination pair included in the termination list returned by matching and the presence / absence of termination information in the list to be matched, and the matching unit does not match the result of the matching As for the termination information, the termination information of the storage means updated based on the control response received during the response waiting time after the response waiting time has elapsed since the termination list was returned by the inquiry. The gist is to match the presence / absence of a termination pair in the termination list.

  The present invention according to claim 2 is a hold request allowable number capable of accepting a hold request for holding the control response with respect to the control request, and a hold that operates from when the hold request is returned from the media gateway. The time of the timer and the time of the control request timer that operates from the time when the control request is transmitted are held in advance, and the response waiting time is the product of the time of the hold timer and the allowable number of hold requests. , The time from when the first control request timer operates until the time when the control request timer expires until the hold request is received, and when receiving the hold request number of the hold request allowable number It is necessary to add the time until the control response is received immediately before the control request timer expires immediately before the control request timer expires. To.

  According to a third aspect of the present invention, there is provided a call processing server storing termination information formed on the basis of presence / absence of termination pairs inside and outside the transfer network held by a media gateway located in the transfer network in a storage means. A response waiting time set in advance as a time required to receive a control response to at least one control request among addition, change, and deletion of a termination pair is stored in the storage unit by the operating media gateway control device. Reading out the termination information from the storage means, generating a matching target list including the termination information, and inquiring the media gateway whether the termination pair currently held by the media gateway exists. The question A step of matching the presence / absence of a termination pair included in the termination list returned by matching with the presence / absence of termination information in the matching target list, and the termination information that does not match as a result of the matching by the inquiry After the response waiting time has elapsed since the termination list was returned, the termination information of the storage list is updated using the termination information of the storage means updated based on the control response received during the response waiting time. And a step of performing matching.

  According to a fourth aspect of the present invention, there is a permissible number of hold requests that can accept a hold request for holding the control response in response to the control request, and a hold that operates from when the hold request is returned from the media gateway. The time of the timer and the time of the control request timer that operates from the time when the control request is transmitted are held in advance, and the response waiting time is the product of the time of the hold timer and the allowable number of hold requests. , The time from when the first control request timer operates until the time when the control request timer expires until the hold request is received, and when receiving the hold request number of the hold request allowable number It is necessary to add the time until the control response is received immediately before the control request timer expires immediately before the control request timer expires. To.

  ADVANTAGE OF THE INVENTION According to this invention, the media gateway control apparatus and media gateway control method which can recover the record state of a matching object list early and correctly, and can prevent misalignment can be provided.

It is a figure which shows the function structure of a media gateway control apparatus. It is a figure which shows the 1st processing flow of a media gateway control apparatus. It is a figure which shows the 2nd processing flow of a media gateway control apparatus. It is a figure which shows the processing flow of state matching. It is a figure for demonstrating the process with respect to the control request between a media gateway control apparatus and a media gateway. It is a figure which shows an example of the response waiting time in the case of expecting a normal control response. It is a figure which shows roughly the communication network structure of a next-generation information communication network. It is a figure which shows the function structure of a call processing server. It is a figure which shows the sequence regarding the control request | requirement of a zone | band. It is a figure for demonstrating the relationship of the termination each hold | maintained by the processing server and the media gateway. It is a figure which shows the processing flow (an example) of a resource management function part. It is a figure which shows the processing flow (another example) of a resource management function part.

  Hereinafter, the present embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram showing a functional configuration of a media gateway control device according to the present embodiment. The media gateway control device 32 includes a call processing function unit 31 that performs call processing of SIP signals and the like, and the presence / absence of termination pairs inside and outside the transfer network held by the media gateway 500 located in the transfer network of the next-generation information communication network. Is a device that operates in the call processing server 300 including a storage unit 33 (hereinafter, simply referred to as “memory”) that stores information associated with session information as termination information, and includes a generation unit 301 and an inquiry unit 302. A butting unit 303, a fitting unit 304, and a storage unit 305. Hereinafter, the function of each component will be described individually and specifically, and the operation and effect of the present invention by providing each component will be described.

  The storage unit 305 is a control request for adding, changing, or deleting a termination pair for the media gateway 500 (such as an AddRequest signal for bandwidth reservation surrounded by a dotted line in FIG. Control response (control response such as a bandwidth reservation AddReply signal, a bandwidth reservation ModifyReply signal, a bandwidth release SubtractReply signal, etc.) surrounded by a dotted line in FIG. It has a function to store the response waiting time set in. As such a storage unit 305, a storage device such as a memory or a hard disk is generally used, and not only inside the media gateway control device 32 but also via a communication network such as the Internet or a telephone line. It is also possible to use an external storage device that can be electrically connected.

  The generation unit 301 has a function of reading the above-described session information from the memory, and using the termination information associated with the session information, generating a matching target list used when matching is performed by the matching unit 303. .

  The inquiry unit 302 has a function of inquiring the media gateway 500 about the presence / absence of termination pairs currently held in the media gateway 500 (presence / absence of termination pairs inside and outside the transfer network).

  The matching unit 303 matches the presence / absence of the termination pair included in the termination list returned by the inquiry in the inquiry unit 302 with the presence / absence of the termination information in the matching target list generated by the generation unit 301, and the result of the matching For termination information that is inconsistent, after a control request is transmitted to the media gateway 500 or after receiving a response to the inquiry in the inquiry unit 302, the response waiting time read from the storage unit 305 has elapsed, It has a function to re-match the presence list with the presence / absence of the termination pair in the termination list using the termination information in the memory updated based on the presence / absence of the termination pair included in the control response received during the response waiting time. That.

  The matching unit 304 has a function of updating the records in the matching target list based on the result of matching in the matching unit 303 and performing matching along the state of the updated matching target list.

  Note that such a media gateway control device 32 corresponds to a conventional resource management function unit (see FIG. 8), and is an IMS (IP Multimedia Subsystem) that realizes multimedia in an IP-based transfer network by call processing control such as SIP. ) Out of RACF (Resource and Admission Control Function) that performs call session control CSCF (Call Session Control Function) and bandwidth usage accumulation and admission determination, pinhole control and policy setting for media gateways. RACF (Resource and Admission Control Function) and SPDF (Service Policy Decision Function) It has usually media gateway controller: is referred to as (MGC Media Gateway Controller).

  On the other hand, the media gateway 500 has C-BGF (Core Border Gateway Function), I-BGF (Interconnection Border Gateway Function), and RCEF (Resource Control Enforcement Function) as a request from the server 300 described above as a request to the server. Based on this, it has a function to create, delete, tie, etc. termination pairs inside and outside the transfer network.

  Next, a first processing flow of the media gateway control device 32 according to the present embodiment will be described. FIG. 2 is a diagram showing a first processing flow of the media gateway control device according to the present embodiment.

  First, the generation unit 301 reads session information stored in the memory, and generates a matching target list using termination information associated with the session information (S101).

  Next, the inquiry unit 302 transmits an AuditValueRequest signal to the target media gateway 500 in order to inquire whether there is a termination pair currently held in the media gateway (S102).

  Here, when an AddRequest signal for newly adding a termination pair is transmitted from the media gateway control device 32 to the media gateway 500 (S103), the termination pair held in the media gateway 500 in accordance with this addition request. Is updated (S104).

  Then, after receiving the AuditValueReply signal as a response to the inquiry in S102, the matching unit 302 determines whether there is a termination pair in the termination list included in the AuditValueReply signal, and whether there is termination information in the matching target list generated in S101. (S105).

  As for the termination information that is inconsistent as a result of the matching in S105, the control response (AddReply) received during the response waiting time after the response waiting time has elapsed after receiving the response to the AuditValueRequest signal in S102 (AuditValueReply signal). Using the termination information (S106) of the memory updated based on the termination information included in the signal), the presence / absence of the termination pair in the termination list used in S105 is checked again (S107). Since the response waiting time is a sufficiently large value considering the time until the AddReply signal is returned to the media gateway control device 32, the termination information of the memory to be matched again in S107 is always based on the AddReply signal. It has been updated.

  Here, when the termination update of the media gateway 500 is successful in S104, an AddReply signal indicating that the MG side is present is transmitted, and the termination information in the memory is updated with the MGC side being present. On the other hand, when the termination pair update fails, an AddReply signal indicating that the MG side is not transmitted is transmitted, and the termination information in the memory is updated with the MGC side being disabled. That is, the termination information in the memory of the media gateway control device 32 is updated based on the success / failure of the termination pair update in the media gateway 500. If successful, an identifier for identifying termination is added to the memory, and the termination ID is completed.

  Finally, the matching unit 304 rewrites the records in the matching target list based on the result of matching in S107, and performs matching according to the rewritten matching target list state (S108).

  Subsequently, a second processing flow of the media gateway control device according to the present embodiment will be described. FIG. 2 is a diagram showing a second processing flow of the media gateway control device according to the present embodiment. The second processing flow describes the case where a SubtractRequest signal for deleting a termination pair is transmitted.

  First, the generation unit 301 reads the session information stored in the memory, and generates a matching target list using the termination information associated with the session information (S201).

  Next, the inquiry unit 302 transmits an AuditValueRequest signal to the target media gateway 500 in order to inquire whether there is a termination pair currently held in the media gateway (S202).

  Here, when the SubtractRequest signal for deleting the termination pair is transmitted from the media gateway control device 32 to the media gateway 500 (S203), the termination pair held in the media gateway 500 is updated according to this deletion request. (S204).

  Then, after receiving the AuditValueReply signal as a response to the inquiry in S202, the matching unit 302 determines whether there is a termination pair in the termination list included in the AuditValueReply signal, and whether there is termination information in the matching target list generated in S201. (S205).

  As for the termination information that does not match as a result of the matching in S205, the control response (SubtractReply) received during the response waiting time after the response waiting time has elapsed after receiving the response to the AuditValueRequest signal in S202 (AuditValueReply signal). Using the termination information (S206) in the memory updated based on the termination information included in the signal), the presence / absence of the termination pair in the termination list used in S205 is matched again (S207).

  Finally, the matching unit 304 rewrites the records in the matching target list based on the result of matching in S207, and performs matching according to the rewritten matching target list state (S208).

  Next, among the processing operations in the first processing flow and the second processing flow, the state matching processing flow for matching the state of the matching target list in the matching unit 304 will be described more specifically with reference to FIG. I will explain.

  First, for each matching target, the matching flag is turned on at the start of matching and the matching state is held (S301), and a matching target list is generated using memory session information and termination information (S302). Then, an AuditValueRequest signal for inquiring whether there is a termination pair is transmitted to the matching media gateway 500, and a termination list of termination IDs matching the range specified in the transmitted AuditValueRequest signal (for example, can be specified by a wild card) is displayed. The included AuditValueReply signal is received from the media gateway 500 (S303). Thereafter, one termination ID is obtained from the AuditValueReply signal and matched with the termination information in the matching target list (S304). If the result of matching is in the matching target list (S305), the record in the matching target list is overwritten with “MGC = Yes, MG = Yes” (S306). On the other hand, if not in the matching target list, the record in the matching target list is overwritten with “MGC = none, MG = present” (S307). Thereafter, the same processing is repeated according to the description of the matching target list, and then the presence or absence of the remaining session information and termination information is confirmed in the matching target list (S308). Is overwritten with “MGC = Yes, MG = No” (S309). Finally, the matching unit 304 performs matching along the state of the records in the matching target list (such as “MGC = Yes, MG = No”) (S310). Note that the processes of S301 to S304 correspond to the operations of S101 to S108 and S201 to S208.

  Finally, the flow of processing in which the matching processing shown in FIG. 4 is added to the first processing flow shown in FIG. 2 will be described. Even when the matching process is added to the second process flow, the basic process flow is the same as the following.

  First, the generation unit 301 reads the session information stored in the memory, and generates a matching target list using termination information associated with the session information (S401 (corresponding to S101)). Specifically, “session information = none, termination information = none”, “MGC = (null character or predetermined default value)”, MG = (null character or predetermined default value), etc., as shown in FIG. It will be generated as a target list.

  Next, the inquiry unit 302 transmits an AuditValueRequest signal to the target media gateway 500 in order to inquire about the presence or absence of the termination pair currently held in the media gateway (S402 (corresponding to S102)).

  Here, when an AddRequest signal for newly adding a termination pair is transmitted from the media gateway control device 32 to the media gateway 500 (S403 (corresponding to S103)), the media gateway 500 holds it according to this addition request. The termination pair being updated is updated (S404 (corresponding to S104)).

  Then, after receiving the AuditValueReply signal as a response to the inquiry in S402, the matching unit 302 determines whether there is a termination pair in the termination list included in the AuditValueReply signal, and whether there is termination information in the matching target list generated in S401. (S405 (corresponding to S105)). Actually, the termination list includes only the “present” termination pair and does not include the “none” termination pair, so the matching unit 302 is included in the termination list. A process of determining whether or not a termination pair is included in the termination information of the matching target list is performed.

  As a result of the matching in S405, if the termination pair included in the received termination list is not in the matching target list, the matching unit 304 sets the matching target list record to “MGC = none, MG = present”. Overwriting (S406 (corresponding to S307)).

  Also, as a result of the matching in S405, for termination information in which the termination pair described in the received termination list is included in the matching target list but does not match, a response to the AuditValueRequest signal in S402 (AuditValueReply signal) is received. Then, after the response waiting time elapses, the memory termination information (S407 (corresponding to S106)) updated based on the termination information included in the control response (AddReply signal) received during the response waiting time is used. Then, the presence / absence of the termination pair in the termination list used in S405 is matched again (S408 (corresponding to S107)). Since the response waiting time is a sufficiently large value considering the time until the AddReply signal is returned to the media gateway control device 32, the termination information of the memory matched again in S408 is always based on the AddReply signal. It has been updated.

  Then, the matching unit 304 rewrites the record of the matching target list based on the result of matching in S408 (S409). Specifically, the record in the matching target list is overwritten with “MGC = Yes, MG = Yes” (S410 (corresponding to S306)).

  Thereafter, the same processing is repeated in accordance with the description of the matching target list, and then the presence or absence of remaining session information and termination information is confirmed in the matching target list (S411 (corresponding to S308)). Overwrites the record in the matching target list with “MGC = Yes, MG = No” (S412 (corresponding to S309)).

  Finally, the matching unit 304 performs matching according to the updated record status of the matching target list (eg, “MGC = Yes, MG = No”) (S413).

  According to the present embodiment, when a control request such as an AddRequest signal or a SubtractRequest signal has already been transmitted to the media gateway 500, a response (AuditValueReply signal) to the inquiry about whether there is a termination pair for the media gateway 500 Is included in the control response such as the AddReply signal and the SubtractReply signal received during the response waiting time after the response waiting time set in advance as the time from receiving the control response to receiving the control response to the control request has elapsed. Match the termination pair status in response to an inquiry using the termination information in the memory updated based on the presence or absence of the termination pair. Is performed, and the record state of the matching target list early and accurately restored, the narrowing combined erroneous can provide a media gateway controller capable of preventing.

  In this embodiment, it has been described that the response waiting time is started after the AuditValueReply signal is received. However, this response waiting time is a time set in advance as a time required to receive the control response. Since it is set as a time at which the control response can be received at least within that time, it is possible to set a response waiting time for each control request. Since the media gateway control device 32 transmits and receives a considerable number of signals until the AuditValueReply signal is received, if the response waiting time is started for each control request from the time when each control request is transmitted, the load is increased. Get higher. Therefore, as described in the first processing flow and the second processing flow, the media gateway control device 32 starts the response waiting time from when the AuditValueReply signal is received and sets the response waiting time to a longer time (longest time). The efficiency of processing performance can be increased.

  The session information and termination information read from the memory in S106 and S206 may be only termination information related to the call to be updated, and the termination information matching in S107 and S207 may use only the termination related to the call. .

  Furthermore, in the present embodiment, a case has been described in which a control request for adding a new termination pair (AddRequest signal) or a control request for deleting (SubtractRequest signal) is made in the first processing flow and the second processing flow. However, even when a control request (ModifyRequest signal) for changing the state of the termination pair is made, it is possible to adapt, and the same effect can be obtained. The matching target list generated in S101 and S201 includes the status and status (INS / OUS) indicating the termination, and the present invention is also applied to the case where there is a mismatch at the timing of changing the status. be able to.

  Furthermore, it is added in the present embodiment that the present invention is applicable even when there are a plurality of media gateways.

  Next, a method for determining the response waiting time will be described. The media gateway control device 32 is a time set in anticipation of receiving the control response, and the time of the control request timer that operates from the time when the control request is transmitted, and within the time of the control request timer for the control request. In the storage unit 305, the number of hold requests that can hold a hold request for holding a control response when the response cannot be returned in the case and the hold timer that operates after the hold request is returned from the media gateway 500 are stored in the storage unit 305 in advance. Keep it. On the other hand, the media gateway 500 also stores the allowable number of pending requests transmitted when establishing communication with the media gateway control device 32.

  First, the media gateway control device 32 starts a control request timer when a control request is transmitted to the media gateway 500, as shown in FIG. It is also possible to retransmit the control request using the initial value of the retransmission timer within the time of the control request timer. In this case, the retransmission time is exponentially within the time of the control request timer. You may make it increase.

  On the other hand, when various information is serially processed in the media gateway 500, it is highly possible that the control response to the control request from the media gateway control device 32 cannot be returned within the time of the control request timer. 500 sends a hold request.

  Thereafter, the media gateway control device 32 that has received the hold request starts the operation of the hold timer, and transmits the control request again after the time of the hold timer expires. At that time, the operation of the control request timer is newly started.

  Thereafter, when the media gateway control device 32 receives a hold request from the media gateway 500, the media gateway control device 32 performs control until the hold request allowable number (corresponding to the maximum number of times that the media gateway control device 32 allows the hold request to be received) is reached. Send the request. If the media gateway 500 still cannot return a control response to the control request when the allowable number of pending requests is reached, a control response indicating an error, an excess error, other no response, etc. are transmitted. .

  Therefore, when a normal control response from the media gateway 500 is expected, as shown in FIG. 6, the first control request timer is calculated by multiplying the product of the hold timer time and the hold request allowable number on the media gateway control device side. Time until the hold request is received immediately before the control request timer expires, and the control request timer that is running when receiving the hold request number of hold requests allowed It is possible to set the time obtained by adding the time until the control response is received immediately before the control request timer expires as the response waiting time Xt. More simply, it is also possible to set as Xt = time of the hold timer on the media gateway control device side × the number of hold requests allowed + the time of the control request timer × 2. Of course, the response waiting time may be a sufficiently long time that is assumed to be necessary until the control response from the media gateway 500 is received. It is possible to arbitrarily change the calculation formula. Of course, it is possible to set each timer for each of a plurality of media gateways.

  Finally, the media gateway control device 32 described in each embodiment is configured by a computer, and each process of each functional block is executed by a program. In addition, each processing operation of the media gateway control device 32 described in each embodiment is recorded as a program on a recording medium such as a compact disk or a floppy (registered trademark) disk, and this recording medium is incorporated in a computer, or The program recorded in the recording medium is downloaded to a computer via an arbitrary communication line or installed from the recording medium, and the computer is operated by the program, whereby the above-described processing operations are performed by the media gateway control device 32. Of course, it can be made to function as.

DESCRIPTION OF SYMBOLS 100 ... User terminal 200 ... Router / switch 300, 300a-300c ... Call processing server 31 ... Call processing function part 32 ... Media gateway control apparatus (resource management function part)
33 ... Storage unit 301 ... Generation unit 302 ... Inquiry unit 303 ... Matching unit 304 ... Matching unit 305 ... Storage unit 500 ... Media gateway S101-S108, S201-S208, S301-S310, S401-S413 ... Step

Claims (4)

In a media gateway controller operating on a call processing server storing termination information formed in the storage means based on the presence / absence of termination pairs inside and outside the transfer network held by a media gateway located in the transfer network,
Storage means for storing a response waiting time set in advance as a time required to receive a control response to at least one control request among addition, change, and deletion of a termination pair;
Generation means for reading out the termination information from the storage means and generating a matching target list including the termination information;
Inquiry means for inquiring of the media gateway whether or not the termination pair currently held by the media gateway exists;
A matching means for matching the presence / absence of a termination pair included in the termination list returned by the inquiry with the presence / absence of termination information in the matching target list,
The abutting means includes
The termination information that is inconsistent as a result of the matching is updated based on the control response received during the response waiting time after the response waiting time has elapsed since the termination list was returned by the inquiry. The media gateway control device, wherein the termination information of the storage means is used to match the presence / absence of a termination pair in the termination list. The allowable number of hold requests that can accept a hold request for holding the control response to the control request, the time of a hold timer that operates from when the hold request is returned from the media gateway, and the control request transmitted The time of the control request timer that operates from when it was
The response waiting time is
The product of the time of the hold timer and the allowable number of hold requests is the time from when the control request timer first operates until the time when the control request timer expires until the hold request is received, The time until the control response is received immediately before the control request timer expires after the operation of the control request timer that is operating when receiving the hold request number of the hold request allowable number is added. The media gateway control device according to claim 1, wherein the media gateway control device is a set time. By a media gateway control device operating on a call processing server storing termination information formed in the storage means based on the presence / absence of termination pairs inside and outside the transfer network held by a media gateway located in the transfer network,
Storing a response waiting time set in advance as a time required to receive a control response to at least one control request among addition, change, and deletion of a termination pair in a storage unit;
Reading the termination information from the storage means, and generating a matching target list including the termination information;
Querying the media gateway for the presence of the termination pair currently held by the media gateway;
A step of matching the presence / absence of a termination pair included in the termination list returned by the inquiry with the presence / absence of termination information in the matching target list;
The termination information that does not match as a result of the matching is updated based on the control response received during the response waiting time after the response waiting time has elapsed since the termination list was returned by the inquiry. Using the termination information in the storage means to match the presence / absence of a termination pair in the termination list;
A media gateway control method comprising: The allowable number of hold requests that can accept a hold request for holding the control response to the control request, the time of a hold timer that operates from when the hold request is returned from the media gateway, and the control request transmitted The time of the control request timer that operates from when it was
The response waiting time is
The product of the time of the hold timer and the allowable number of hold requests is the time from when the control request timer first operates until the time when the control request timer expires until the hold request is received, The time until the control response is received immediately before the control request timer expires after the operation of the control request timer that is operating when receiving the hold request number of the hold request allowable number is added. The media gateway control method according to claim 3, wherein the time is a predetermined time.

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