JP2014030118A - Network system, session control server, and subscriber server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately identify a congestion restriction target range, and perform fine congestion control.SOLUTION: A congestion control server 1 transmits congestion control information including identification information of a session control server 2 in which a congestion occurred and range information indicating a restriction target range to each session control server 2. The session control server 2 includes: receiving means which receives the congestion control information; acquisition means which acquires identification information of the session control server 2 housing a communication terminal 4 of a connection destination and range information indicating a range in which the communication terminal of the connection destination exists from a subscriber server 3 when receiving a connection request from the communication terminal 4; and determination means which compares the identification information and range information acquired by the acquisition means with the identification information and range information included in the congestion control information, determines that the connection request is a congestion restriction target when the identification information and range information acquired by the acquisition means match the identification information and range information included in the congestion control information, and determines that the connection request is not the congestion restriction target when the identification information and range information acquired by the acquisition means do not match the identification information and range information included in the congestion control information.

Description

  The present invention relates to a network system, a session control server, and a subscriber server that regulate transmission to a range where congestion occurs when congestion occurs in a network.

  In a communication system, there is a possibility that connection requests will be concentrated for some reason, resulting in a congestion state where normal processing cannot be continued. In response to this, once input to locations where excessive processing requests are concentrated is restricted from the earliest possible stage, normal processing is performed for connection requests to locations where processing requests are concentrated. A method of congestion control is used in which the restriction that has been implemented is released after the state is restored. Here, if the implementation range of the regulation is excessive, recovery from the congestion state is easy, but there is a concern that the range of influence on the damage to the user is expanded. On the other hand, if the range in which this restriction is implemented is too small, concentration of connection requests cannot be prevented, and there is a problem that a state in which the state cannot be recovered from the congestion state continues. For this reason, various proposals have been made as described in Patent Document 1, for example, regarding the regulation method associated with this congestion control.

JP 2010-200029

  In the congestion control method of Patent Document 1, congestion control is performed on a session control server basis for performing call control between communication terminals. However, congestion occurring in an actual communication system does not always depend on the configuration of a communication system such as a server. For this reason, the congestion restriction method disclosed in Patent Document 1 cannot accurately specify the object of restriction, and may not be able to implement appropriate congestion control. For example, even if congestion occurs only in a certain range of a server, the restriction range for the actual congestion range is excessive because the congestion control is performed on the entire server. Therefore, there is a problem that the influence on the user becomes large.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to accurately specify a range to be subject to congestion regulation and to perform fine congestion control, a session control server, and a subscription Providing a user server.

  In order to achieve the above object, the present invention provides a network system having a congestion control server and a plurality of session control servers, wherein the congestion control server identifies information of a session control server in which congestion has occurred when congestion occurs. And congestion control information including range information indicating a restriction target range subject to congestion restriction, each of the session control servers transmits the congestion control information from the congestion control server. When receiving the connection request from the receiving means and the communication terminal, the identification information of the session control server that accommodates the connection destination communication terminal specified in the connection request, and the range where the connection destination communication terminal exists Included in the congestion control information, the acquisition means for acquiring the range information shown, the identification information and the range information acquired by the acquisition means, and the congestion control information Discriminating means that compares different information and range information and determines that the connection request is subject to congestion regulation if they match, and discriminates that the connection request is not subject to congestion regulation if they do not match And comprising.

  The present invention further includes a subscriber server that holds, for each communication terminal, identification information of a session control server that accommodates the communication terminal and range information indicating a range in which the communication terminal exists in the network system. The session control server acquisition means acquires identification information of a session control server that accommodates the connection destination communication terminal and range information indicating a range in which the connection destination communication terminal exists from the subscriber server. To do.

  The present invention is a session control server, and when congestion occurs, congestion control information including identification information of other session control devices in which congestion has occurred and range information indicating a restriction target range subject to congestion restriction, When receiving the connection request from the congestion control server and the communication terminal, the identification information of the session control server that accommodates the connection destination communication terminal specified in the connection request, and the connection destination communication terminal When the acquisition unit that acquires range information indicating an existing range, the identification information and range information acquired by the acquisition unit, and the identification information and range information included in the congestion control information are compared, and they match And determining means for determining that the connection request is subject to congestion regulation and discriminating that the connection request is not subject to congestion regulation if they do not match.

  The present invention is a subscriber server, and for each communication terminal, storage means for storing identification information of a session control server that accommodates the communication terminal, and range information indicating a range in which the communication terminal exists, In response to a request from the session control server, the identification information of the session control server that accommodates the communication terminal specified in the request and range information indicating the range in which the communication terminal exists are read from the storage unit, and the request Transmitting means for transmitting to the original session control server.

  According to the present invention, it is possible to provide a network system, a session control server, and a subscriber server that accurately specify a range to be subject to congestion regulation and perform fine congestion control.

1 is a diagram illustrating an overall configuration of a network system according to an embodiment of the present invention. It is a block diagram which shows the structure of a session control server. It is a figure which shows an example of a subscriber information storage part. It is explanatory drawing for demonstrating the operation | movement of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a network system according to an embodiment of the present invention. The network system according to this embodiment includes a congestion control server 1, a plurality of session control servers 2, and a subscriber server 3.

  When congestion occurs in any of the session control servers 2, the congestion control server 1 transmits congestion control information for notifying that the congestion has occurred to each session control server 2 in the network. The congestion control information of this embodiment includes identification information of a session control server in which congestion has occurred, and range information indicating a restriction target range subject to congestion restriction. The range information indicating the restriction target range indicates an independent range that is not restricted by the configuration of the network system. For example, it is conceivable to use an area code assigned to each region such as an administrative district.

  In the present embodiment, when congestion occurs, range information (area code or the like) is introduced so that a range that should be subject to congestion regulation can be appropriately specified. When congestion occurs, the congestion control server 1 uses this range information to notify the subordinate session control server of the range subject to congestion regulation.

  FIG. 2 is a block diagram showing the configuration of each session control server 2. The illustrated session control server 2 includes a session control unit 21, a determination unit 22, a congestion control unit 23, a subscriber information update unit 24, and a storage unit 25. The session control unit 21 (acquisition means) controls a call (session) between the communication terminals 4. In addition, when the session control unit 21 of the present embodiment receives a connection request from the communication terminal 4 accommodated therein, the session control unit 21 identifies the identification information of the session control server 2 that accommodates the connection destination communication terminal 4 specified by the connection request. And range information indicating a range including the connection destination communication terminal 4 is acquired.

  The determination unit 22 (determination means) compares the identification information and range information acquired by the session control unit 21 with the identification information and range information included in the congestion control information notified from the congestion control server 1, and the two match. In the case where the connection request is made, it is determined that the connection request from the communication terminal 4 is subject to congestion regulation, and in the case where they do not match, the connection request from the communication terminal is judged not to be subject to congestion restriction.

  The congestion control unit 23 (reception unit) receives the congestion control information transmitted from the congestion control server 1, and identifies the session control server in which the congestion occurs included in the congestion control information and the restriction subject to congestion regulation. Range information indicating the target range is stored in the storage unit 25. Further, when the determination unit 22 determines that the connection request from the communication terminal 4 is subject to congestion regulation, the congestion control unit 23 regulates the connection request. When the congestion state is resolved, the congestion control server 1 transmits a congestion resolution notification including the identification information and range information of the session control server in which the congestion is resolved to each session control server 2. As a result, the congestion control unit 23 of each session control server 2 deletes the identification information and range information of the session control server in which the congestion has occurred, stored in the storage unit 25.

  When the communication terminal 4 is a mobile communication terminal such as a smartphone, the subscriber information update unit 24 receives a register signal that notifies that the communication terminal 4 has moved to a range (area) managed by the session control server 2. The subscriber information of the communication terminal stored in the subscriber server 3 is updated.

  In the example illustrated in FIG. 1, the session control servers # 1 to # 4 are assumed to accommodate each communication terminal 4 (subscriber) located in at least one range (area, area). For example, the session control server # 1 accommodates the communication terminals 4 in the area a (area code: 001) and the area b (area code: 002), and the session control server # 2 includes the area c (area code: 003). ), And the session control server # 3 accommodates some communication terminals 4 in the area d (area code: 004) and the area e (area code: 005). # 4 accommodates a part of the area e (area code: 005) and the communication terminal 4 in the area f (area code: 006). It is assumed that another network is connected to session control server # 6 and has a function as a gateway.

  The subscriber server 3 includes a subscriber information storage unit 31 in which subscriber information related to the communication terminal 4 (subscriber) in the network is stored, and the communication terminal 4 designated in response to a request from the session control server 2. It is a server that provides subscriber information. In the subscriber information storage unit 31 of the present embodiment, for example, as shown in FIG. 3, for each communication terminal 4, identification information (such as a telephone number) of the communication terminal and a session control server that accommodates the communication terminal are stored. Identification information and range information (area code or the like) indicating a range where the communication terminal is located are stored in association with each other.

  In addition, the information memorize | stored in the subscriber information storage part 31 is updated at any time according to the movement of the said communication terminal 4, when the communication terminal 4 is a mobile communication terminal. Specifically, when the communication terminal 4 moves, the communication terminal 4 transmits a register signal to the session control server 2 in the destination area. The register signal includes identification information (such as a telephone number) of the communication terminal 4 and position information. Note that the communication terminal 4 may not transmit the position information, and the subscriber information update unit 24 of the session control server 2 may perform conversion from information such as an IP address to range information. When the subscriber information update unit 24 of the session control server 2 receives the register signal, the subscriber information update unit 24 converts the position information included in the register signal into range information corresponding to the position information. Then, the subscriber information update unit 24 transmits an update request including the identification information of the communication terminal 4, the identification information of its own session control server 2, and the converted range information to the subscriber server 3. The subscriber server 3 receives the update request, and updates the identification information and range information of the session control server corresponding to the communication terminal specified by the update request, stored in the subscriber information storage unit 31. The network administrator may manually update the identification information and / or range information of the session control server.

  The congestion control server 1, the session control server 2, and the subscriber server 3 described above are, for example, general-purpose computers that include a CPU, a memory, an external storage device such as an HDD, an input device, and an output device. The system can be used. In this computer system, each function of each device is realized by the CPU executing a predetermined program loaded on the memory. For example, the functions of the congestion control server 1, the session control server 2, and the subscriber server 3 are configured such that the CPU of the congestion control server 1 is a program for the congestion control server 1 and a session is a program for the session control server 2. This is realized by the CPU of the control server 2 and the CPU of the subscriber server 3 in the case of the program for the subscriber server 3 being executed. The program for the congestion control server 1, the program for the session control server 2, and the program for the subscriber server 3 are stored on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD-ROM. It can be stored or distributed over a network.

  Next, the operation of this embodiment will be described.

  FIG. 4 is an explanatory diagram showing the operation of this embodiment. In the example shown in FIG. 4, in a state where calls to communication terminals in area a are concentrated and congestion occurs in session control server # 1, communication terminal B in area a is changed to communication terminal A in area a. This shows the operation when a connection request (call) is generated.

  When session control server # 1 detects the occurrence of congestion due to concentration of calls to one or more communication terminals in area a, warning message (alarm indicating that congestion has occurred to congestion control server 1) ) Is transmitted (S11).

  When the congestion control server 1 receives the warning message, the congestion control server 1 notifies the network administrator of the occurrence of the congestion by displaying the warning message on a display or sounding a warning sound. The network administrator analyzes the contents of the warning message, the log information of the session control server # 1, and the like, and inputs the congestion control information. The congestion control information includes identification information (in the example shown, server1.block1.ns.co.jp) of the session control server # 1 where the congestion has occurred, and a restriction target range (in the example shown in the figure) that is subject to congestion restriction. , And an area code (001) indicating the area a causing the congestion.

  The congestion control server 1 receives an instruction from the network administrator, and transmits congestion control information for notifying that congestion has occurred to each session control server in the network, so that the session subject to congestion regulation. An instruction is given to restrict communication (call connection) addressed to the restricted range of the control server (S12). The congestion control information shown in the figure includes the identification information of the session control server # 1 where the congestion has occurred and the restriction target range (area code: 001). Here, it is assumed that the congestion control server 1 transmits the congestion control information in response to an instruction from the network administrator. However, the congestion control server 1 automatically receives the warning message of S11 as a trigger. Control information may be transmitted to each session control server.

  The congestion control unit 23 of each session control server stores the congestion control information transmitted from the congestion control server 1 in the storage unit 25. In such a congestion state, the session control unit 21 of the session control server # 4 is addressed to the communication terminal A (01-1210-1111) from the communication terminal B (region f) accommodated in the session control server # 4. Connection request (call) is received (S13). Thereby, the session control part 21 inquires the subscriber server 3 about the information regarding the connection destination designated by the received connection request (S14). At this time, the session control unit 21 designates the number of the connection destination designated in the connection request (01-1210-1111 in the illustrated example), and transmits an inquiry request to the subscriber server. The connection destination number is a unique number assigned to a communication terminal such as a subscriber number or a telephone number.

  Upon receiving the inquiry request, the subscriber server 3 reads the session control server identification information and range information (area code) corresponding to the number specified in the request from the subscriber information storage unit 31, and Transmit to # 4 (S15). The session control server identification information is the identification information of the session control server that accommodates the specified number of communication terminals, and the range information indicates the range / region where the specified number of communication terminals exist. It is.

  The determination unit 22 of the session control server # 4 includes the identification information and range information of the session control server transmitted from the subscriber server 3, the identification information of the session control server included in the congestion control information stored in the storage unit 25, and Compare with range information. If the two match, the determination unit 22 determines that the connection destination of the connection request in S13 is the restriction target range notified by the congestion control server 1 in S12 and subject to the congestion restriction, and the congestion target session. Since it is a connection request directed to the control server, it is determined that the connection request is subject to congestion regulation. When it is determined that the congestion is to be regulated, the congestion control unit 23 regulates the connection request. For example, for a certain percentage of connection requests subject to congestion regulation, the congestion control unit 23 provides guidance such as “the number you have dialed is very crowded” to the requesting communication terminal. The call connection process is not performed, and only the remaining proportion of connection requests are transmitted to the session control unit 21, and a normal call connection process is performed by session control to connect the call to the connection destination communication terminal A.

  On the other hand, when the two do not match or when the congestion control information is not stored in the storage unit 25 (that is, when it is not in the congestion state), the determination unit 22 determines that the connection request of S13 is not subject to congestion regulation. To do. In this case, the session control unit 21 performs a normal call connection process to connect the call to the connection destination communication terminal A.

  In the present embodiment described above, congestion information such as an area code is newly introduced, which is not limited by the network system configuration, so that it is possible to appropriately specify the scope to be subject to congestion regulation. When the congestion occurs, the control server notifies the subordinate session control servers of the range information as congestion control information. Each session control server includes this range information in the connection destination information acquired from the subscriber server in the call processing for the connection request from the communication terminal. It is possible to determine whether or not is subject to congestion regulation.

  As a result, in the present embodiment, it becomes possible to appropriately select the range for performing the restriction from the range designation suitable for the purpose of the congestion control independent of the configuration of the network system in performing the congestion control. Effective congestion regulation can be implemented. In addition, regarding the restriction that has been carried out beyond the necessary range in the conventional congestion control technology, the restriction range is expected to be optimized, and it becomes possible to eliminate the excessive restriction.

  Further, in the present embodiment, the range information of each communication terminal is stored in the subscriber information storage unit of the subscriber server even in the 0A0 number band where the session control server and the communication terminal number band are not linked. Therefore, it is particularly effective when the restriction is performed by narrowing down the restriction range.

  In the present embodiment, it is determined whether or not the connection request from the communication terminal is subject to congestion regulation using the identification information and range information of the session control server. As a result, for example, even in a case where one region spans a plurality of session control servers, such as a region e shown in FIG. 1, congestion control can be appropriately performed.

  In addition, this invention is not limited to the said embodiment, Many deformation | transformation are possible within the range of the summary.

1: Congestion control server 2: Session control server 21: Session control unit 22: Discriminating unit 23: Congestion control unit 24: Subscriber information update unit 25: Storage unit 3: Subscriber server 4: Communication terminal

Claims (4)

A network system having a congestion control server and a plurality of session control servers,
The congestion control server
When congestion occurs, congestion control information including identification information of the session control server in which congestion has occurred and range information indicating the restriction target range subject to congestion restriction is transmitted to each session control server,
Each of the session control servers
Receiving means for receiving the congestion control information from the congestion control server;
When a connection request from a communication terminal is received, identification information of a session control server that accommodates the connection destination communication terminal specified in the connection request, and range information indicating a range in which the connection destination communication terminal exists are acquired. Acquisition means to
Compare the identification information and range information acquired by the acquisition means with the identification information and range information included in the congestion control information, and if both match, determine that the connection request is subject to congestion regulation, And a discriminating means for discriminating that the connection request is not subject to congestion regulation when the two do not match. The network system according to claim 1, wherein
Each communication terminal further includes a subscriber server that holds identification information of a session control server that accommodates the communication terminal, and range information indicating a range in which the communication terminal exists,
The session control server acquisition means acquires from the subscriber server identification information of a session control server accommodating the connection destination communication terminal and range information indicating a range where the connection destination communication terminal exists. A network system characterized by A session control server,
Receiving means for receiving, from the congestion control server, congestion control information including identification information of another session control server in which congestion has occurred and range information indicating a restriction target range subject to congestion restriction;
When a connection request from a communication terminal is received, identification information of a session control server that accommodates the connection destination communication terminal specified in the connection request, and range information indicating a range in which the connection destination communication terminal exists are acquired. Acquisition means to
Compare the identification information and range information acquired by the acquisition means with the identification information and range information included in the congestion control information, and if both match, determine that the connection request is subject to congestion regulation, A session control server comprising: a determining unit that determines that the connection request is not subject to congestion regulation when the two do not match. A subscriber server,
Storage means for storing, for each communication terminal, identification information of a session control server that accommodates the communication terminal, and range information indicating a range in which the communication terminal exists;
In response to a request from the session control server, the identification information of the session control server that accommodates the communication terminal specified in the request and range information indicating the range in which the communication terminal exists are read from the storage unit, and the request And a transmission means for transmitting to the original session control server.

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