JP5347743B2 - Communication system, control node selection device, control node selection method, and program - Google Patents

Description

  The present invention relates to a communication system, a control node selection device, a control node selection method, and a program for selecting a control node that performs communication control.

  In recent years, in a wireless communication system, when there are a plurality of PCRFs (Policies and Charging Rule Functions) which are control nodes that perform communication control including a policy function and a charging function for a subscriber, one PCRF out of the plurality of PCRFs. A system provided with a DRA (Diameter Routing Agent), which is a control node selection device that selects a node, is considered (for example, see Non-Patent Document 1).

  FIG. 16 is a diagram illustrating one form of a general communication system.

  In the communication system shown in FIG. 16, DRA 1000, PCRF 2000, S / P-GW 3000, HSS 4000, UE 5000, eNodeB 6000, and MME 7000 are provided. Here, as the transfer method, either the Proxy method or the Redirect method may be used.

  DRA 1000 is a control node selection device that transfers the CCR signal to PCRF 2000 when the Proxy method is used as a transfer method of a CCR (Credit-Control-Request) signal that is a control request signal transmitted from S / P-GW 3000 It is. Further, when the redirect method is used as the transfer method of the CCR signal, the DRA 1000 does not transfer the CCR signal transmitted from the S / P-GW 3000 to the PCRF 2000, and is a CCA (Credit-Control) that is a response signal to the CCR signal. -Answer) signal is generated, and the CCA signal is transmitted to the S / P-GW 3000 including the PCRF selection result information indicating the PCRF selection result.

  The PCRF 2000 is a control node that performs communication control including a policy function and a charging function for the UE 5000 based on the transferred CCR signal and the like.

  S / P-GW (Serving-Gateway / Packet Data Node-Gateway) 3000 is a gateway for user packet routing, policy application, packet filtering for each subscriber, support charging, lawful intercept and packet screening, etc. Device. Further, the S / P-GW 3000 transmits a CCR signal to the DRA 1000. Further, when a CCA signal is transmitted from the DRA 1000 that has transmitted the CCR signal, the S / P-GW 3000 transmits (transfers) the CCR signal to the PCRF 2000 based on the PCRF selection result information included in the CCA signal.

  The HSS (Home Subscriber Server) 4000 is a subscriber information storage device that stores subscriber information such as subscriber identification information for identifying the UE 5000 and contents of services to be provided to the UE 5000.

  A UE (User Equipment) 5000 is a terminal device used by a subscriber.

  The eNodeB 6000 is a radio base station.

  The MME (Mobility Management Entity) 7000 is an in-house device that performs mobility management such as authentication of the UE 5000, paging processing of the UE 5000, location registration of the UE 5000, terminal call at incoming, and handover based on information stored in the HSS 4000. is there.

  FIG. 17 is a diagram for explaining a data flow among the PCRF 2000, the S / P-GW 3000, and the HSS 4000 shown in FIG.

  As shown in FIG. 17, in response to the policy request from the S / P-GW 3000, the PCRF 2000 acquires subscriber data (subscriber information) from the HSS 4000 and performs processing.

  There are generally a plurality of PCRFs as described above. Therefore, DRA is necessary to select which PCRF is used to perform communication control among the plurality of PCRFs.

  In recent years, communication systems in which a plurality of DRAs exist have also become widespread.

  FIG. 18 is a diagram illustrating a form of a communication system in which a plurality of DRAs exist.

  In the communication system shown in FIG. 18, DRA 1000-1 to 1000-3, PCRF 2000-1 to 2000-3, and S / P-GW 3000 are provided. When the CCR signal is transferred by the redirect method, the S / P-GW 3000 and RCRF 2000-1 to 2000-3 are also connected.

  When the Proxy method is used as a transfer method for the CCR signal transmitted from the S / P-GW 3000, the DRA 1000-1 to 1000-3 transfers the CCR signal to the PCRF 2000-1 to 2000-3. At this time, the DRAs 1000-1 to 1000-3 select one PCRF among the PCRFs 2000-1 to 2000-3 and transfer the CCR signal. Further, when the redirect method is used as the transfer method of the CCR signal, the DRA 1000-1 to 1000-3 does not transfer the CCR signal transmitted from the S / P-GW 3000 to the PCRF 2000-1 to 2000-3. A CCA (Credit-Control-Answer) signal that is a response signal to the CCR signal is generated, and the CCA signal is transmitted to the S / P-GW 3000 including PCRF selection result information indicating a PCRF selection result.

  The PCRF 2000-1 to 2000-3 controls the subscriber based on the transferred CCR signal.

  The S / P-GW 3000 transmits the CCR signal to the DRA 1000-1 to 1000-3.

  FIG. 19 is a diagram illustrating an example of a transfer route of the CCR signal in FIG. Here, a case where the Proxy method is used as a CCR signal transfer method will be described as an example.

  As shown in FIG. 19, when the DRA 1000-1 to 1000-3 selects the PCRF 2000-1 as the transfer destination of the CCR signal, the CCR signal transmitted from the S / P-GW 3000 is the DRA 1000-1 to 1000- 3 is transferred to the PCRF 2000-1. That is, the DRAs 1000-1 to 1000-3 transfer the CCR signal transmitted from the S / P-GW 3000 to the PCRF 2000-1. When the redirect method is used as the CCR signal transfer method, the CCR signal is transmitted (transferred) from the S / P-GW 3000 to the PCRF 2000-1 without passing through the DRA 1000-1 to 1000-3.

3GPP TS 29.213 V8.2.0 (2008-12)

  FIG. 20 is a diagram illustrating an example of a transfer route of the CCR signal when a failure occurs in the PCRF 2000-1 in the state illustrated in FIG. Here, a case where the Proxy method is used as a CCR signal transfer method will be described as an example.

  As shown in FIG. 20, when a failure occurs in the PCRF 2000-1, the DRAs 1000-1 to 1000-3 determine that the PCRF 2000-1 cannot be used. Therefore, the DRAs 1000-1 to 1000-3 each select a PCRF other than the PCRF 2000-1 as the transfer destination of the CCR signal.

  A CCR signal transmitted from one subscriber needs to be processed by one PCRF. However, as shown in FIG. 20, when DRA 1000-1 selects PCRF 2000-2 as the transfer destination of the CCR signal, and DRA 1000-2 to 1000-3 selects PCRF 2000-3 as the transfer destination of the CCR signal, A CCR signal transmitted from one subscriber is processed by a plurality of PCRFs. If such processing has been performed, processing of the CCR signal for each subscriber is not performed normally.

  That is, when a failure occurs in the PCRF that is the route destination of the CCR signal, there is a problem in that the substitute PCRF cannot be dynamically selected correctly.

  The objective of this invention is providing the communication system, the control node selection apparatus, the control node selection method, and program which solve the subject mentioned above.

The communication system of the present invention includes:
A plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication, and a control node that is stored in advance in a route management table for each of the plurality of control nodes In a communication system including a plurality of control node selection devices that are selected as transfer destinations of control request signals,
The plurality of control node selection devices include a main control node selection device and a subordinate control node selection device,
The master control node selection device and the subordinate control node selection device determine whether the control node is available;
The main control node selection device is a session identification information given to session processing included in the control request signal, subscriber identification information given to the subscriber, and a transfer destination of the control request signal A session management table for storing the control node in association with the session process from start to end, and when the control request signal is transmitted, the control request signal is transmitted to the control request signal in the session management table. When the control node associated with the included subscriber identification information is searched from the session management table and the subscriber identification information included in the transmitted control request signal does not exist in the session management table, or If it is determined that the retrieved control node is not usable, the control node that is determined to be usable is controlled by the transfer destination. If the control request signal is a signal sent from the subordinate control node selection device, the control node is selected as the node. Otherwise, the control node is selected as the transfer destination control node. After determining that the control node associated with the subscriber identification information included in the request signal and the route management table is available, the subscriber identification information of the subscriber disappeared in the session management table In this case, a relay release signal indicating that is transmitted to the subordinate control node selection device,
The subordinate control node selection device further determines that the control node stored in the path management table is not usable until the relay release signal is transmitted from the main control node selection device. The control request signal transmitted from the subscriber is relayed to the main control node selection device.

The control node selection device of the present invention is
A control node selection device that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication,
A routing unit for selecting the control node of the transfer destination of the control request signal;
A static route management unit that stores and manages a control node of a transfer destination of the control request signal for each subscriber in advance in a route management table;
An opposing node state manager that determines whether the control node is available;
Session identification information uniquely assigned to session processing included in the control request signal, subscriber identification information uniquely assigned to the subscriber, and a control node that is a transfer destination of the control request signal From the start to the end of this, when stored and managed in the session management table in association, when the control request signal is transmitted, subscriber identification information included in the control request signal in the session management table, A monitoring session management unit that retrieves the associated control node from the session management table;
The routing unit, when subscriber identification information included in the transmitted control request signal does not exist in the session management table, or when the control node searched by the monitoring session management unit is not available When the opposite node state management unit determines, the control node that is determined to be usable by the opposite node state management unit is selected as the transfer destination control node; otherwise, the monitoring session management unit searches A control node is selected as the transfer destination control node.

The control node selection device of the present invention is
A control node selection device that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication,
A routing unit for selecting the control node of the transfer destination of the control request signal;
A static route management unit that stores and manages a control node of a transfer destination of the control request signal for each subscriber in advance in a route management table;
An opposing node state manager that determines whether the control node is available;
In the routing unit, the opposite node state management unit determines that the control node stored in the route management table is not usable, and then uses another control node selection device that relays transfer of the control request signal. A control node that relays a control request signal transmitted from the subscriber to the relay control node selection device until a relay release signal indicating that the relay is released is transmitted from a relay control node selection device. Selection device.

The control node selection method of the present invention includes
A plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication, and a control node that is stored in advance in a route management table for each of the plurality of control nodes In a communication system comprising a plurality of control node selection devices that are selected as transfer destinations of control request signals, a control node that selects one control node from among the plurality of control nodes as a control node to which the control request signal is transferred A selection method,
A process for the control node selection device to determine whether the control node is available;
Of the plurality of control node selection devices, a main control node selection device includes session identification information given to session processing included in the control request signal, subscriber identification information given to the subscriber, A process of storing a control node, which is a transfer destination of the control request signal, in association with the session management table from the start to the end of the session process;
When the control request signal is transmitted, the main control node selection device searches the session management table for a control node associated with subscriber identification information included in the control request signal in the session management table. Processing to
When the main control node selection device does not have subscriber identification information included in the transmitted control request signal in the session management table, or when the searched control node is unavailable Selecting a control node determined to be usable as the transfer destination control node; otherwise, selecting the searched control node as the transfer destination control node;
In the main control node selection device, the control request signal is transmitted from a subordinate control node selection device that is a control node selection device other than the main control node selection device among the plurality of control node selection devices. If it is determined that the control node associated with the subscriber identification information included in the control request signal and the route management table is available, the subscriber identification of the subscriber is stored in the session management table. When there is no information, a process of transmitting a relay release signal indicating that to the subordinate control node selection device;
The subordinate control node selection device determines that the control node stored in the route management table is not usable until the relay release signal is transmitted from the main control node selection device. And a process of relaying a control request signal transmitted from a subscriber to the main control node selection device.

The program of the present invention is
To cause a control node selection apparatus that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber who performs communication. The program of
A procedure for determining whether the control node is available;
Session identification information uniquely assigned to session processing included in the control request signal, subscriber identification information uniquely assigned to the subscriber, and a control node that is a transfer destination of the control request signal From the start to the end of the process, store in the session management table in association with each other,
A procedure for searching the session management table for a control node associated with subscriber identification information included in the control request signal when the control request signal is transmitted;
When subscriber identification information included in the transmitted control request signal does not exist in the session management table, or when it is determined that the searched control node is not available, it is determined that it can be used. Selecting a control node as the transfer destination control node; otherwise, selecting the searched control node as the transfer destination control node;
When the control request signal is transmitted from a control node selection device other than the control node selection device among the plurality of control node selection devices, the transfer destination of the control request signal for each subscriber After determining that the control node associated with the subscriber identification information included in the control request signal is available in the route management table that stores the control node in advance, the subscriber is stored in the session management table. When there is no subscriber identification information, a relay release signal indicating that fact is transmitted to another control node selection device that has transmitted the control request signal.

The program of the present invention is
To cause a control node selection apparatus that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber who performs communication. The program of
A procedure for determining whether or not a control node stored in a path management table storing in advance a control node to which the control request signal is transferred for each subscriber is available;
After determining that the control node stored in the path management table is not usable, the relay is released from the relay control node selection device which is another control node selection device that relays the transfer of the control request signal. Until the relay release signal indicating is transmitted, the control request signal transmitted from the subscriber is relayed to the relay control node selection device.

  As described above, in the present invention, the main control node selection device includes the session identification information given to the session processing included in the control request signal, the subscriber identification information given to the subscriber, and the control. The control node that is the transfer destination of the request signal is stored in the session management table in association with the session process from the start to the end, and when the control request signal is transmitted, the control request signal in the session management table The control node associated with the subscriber identification information included in the session management table is searched from the session management table, and the subscriber identification information included in the transmitted control request signal does not exist in the session management table, or the retrieved control If it is determined that the node is not available, the control node that is determined to be available is used as the transfer destination control node. Otherwise, if the searched control node is selected as the transfer destination control node, and the control request signal is transmitted from the subordinate control node selection device, the subscriber included in the control request signal If it is determined that the control node associated with the identification information and the route management table is available, and if there is no subscriber identification information of the subscriber in the session management table, a relay release signal indicating that is subordinated. Until the slave control node selection device transmits a relay release signal after the subordinate control node selection device determines that the control node stored in the route management table is not available. During this period, the control request signal transmitted from the subscriber is relayed to the main control node selection device. Dynamic selection control of the root destination control node can be easily performed.

It is a figure which shows one Embodiment of the communication system of this invention. It is a figure which shows an example of an internal structure of the master DRA shown in FIG. It is a figure which shows an example of the information of the transfer destination of the CCR signal for every subscriber which the path | route management table shown in FIG. 2 has memorize | stored. It is a figure which shows an example of the information which the opposite node state management part shown in FIG. 2 manages. It is a figure which shows an example of matching with the session identification information for every subscriber which the session management table shown in FIG. 2 memorize | stores, and the information of the transfer destination of a CCR signal. It is a figure which shows an example of an internal structure of the slave DRA shown in FIG. It is a figure which shows an example of the information of DRA which the opposite node state management part shown in FIG. 6 manages. FIG. 6 is a sequence diagram for explaining a control node normal selection process in the master DRA shown in FIG. 1. It is a sequence diagram for demonstrating the new detour selection process of the control node in the master DRA shown in FIG. It is a sequence diagram for demonstrating the detour selection process during the detour of the control node in the master DRA shown in FIG. FIG. 6 is a sequence diagram for explaining further detour selection processing of a route that has been detoured by a control node in the master DRA illustrated in FIG. 1. FIG. 6 is a sequence diagram for explaining a control node normal selection process in the slave DRA shown in FIG. 1. FIG. 6 is a sequence diagram for explaining a relay selection start process in the slave DRA shown in FIG. 1. It is a sequence diagram for demonstrating the continuation process of the relay selection in the slave DRA shown in FIG. FIG. 7 is a sequence diagram for explaining relay selection release processing in the slave DRA shown in FIG. 1. It is a figure which shows one form of a general communication system. It is a figure for demonstrating the data flow among PCRF shown in FIG. 16, S / P-GW, and HSS. It is a figure which shows one form of the communication system with which multiple DRA exists. It is a figure which shows an example of the transfer route | root of the CCR signal in FIG. It is a figure which shows an example of the transfer route | root of a CCR signal when a failure generate | occur | produces in PCRF in the state shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an embodiment of a communication system according to the present invention.

  As shown in FIG. 1, this embodiment includes DRA 100-1 to 100-3, PCRF 200-1 to 200-3, and S / P-GW 300. Here, as the transfer method, either the Proxy method or the Redirect method may be used. In addition, when transferring a CCR signal, which will be described later, using the redirect method, the S / P-GW 300 and RCRF 200-1 to 200-3 are also connected.

  The S / P-GW 300 is the same as the S / P-GW 3000 shown in FIG. 18, and is a gateway device that transmits CCR signals that are control request signals to the DRAs 100-1 to 100-3. The CCR signal includes a signal type indicating a signal type (for example, a generation request for requesting generation of a resource, a change request for requesting a change in the state of a resource, a deletion request for requesting deletion of a resource), and the like. Session identification information uniquely given to the session to be processed and subscriber identification information which is information for identifying the subscriber uniquely assigned to the subscriber are included. In addition, when a CCA signal described later is transmitted from the DRA 100-1 to 100-3 that transmitted the CCR signal, the S / P-GW 300 transmits the CCR signal based on the PCRF selection result information included in the CCA signal. Transmit (transfer) to PCRF 200-1 to 200-3.

  PCRFs 200-1 to 200-3 are the same as PCRF 2000-1 to 2000-3 shown in FIG. 18, and are control nodes that control subscribers based on the transferred CCR signals.

  The DRA 100-1 to 100-3, when the Proxy method is used as the transfer method of the CCR signal transmitted from the S / P-GW 300, controls the node selection apparatus that transfers the CCR signal to the PCRFs 200-1 to 200-3 It is. At this time, the DRAs 100-1 to 100-3 select one PCRF among the PCRFs 200-1 to 200-3, and transfer the CCR signal to the selected PCRF. When the redirect method is used as the transfer method of the CCR signal, the DRA 100-1 to 100-3 does not transfer the CCR signal transmitted from the S / P-GW 300 to the PCRF 200-1 to 200-3, A CCA (Credit-Control-Answer) signal that is a response signal to the CCR signal is generated, and the CCA signal including the PCRF selection result information indicating the PCRF selection result is transmitted to the S / P-GW 300.

  The DRA 100-1 is a main control node selection device (relay control node selection device that relays a CCR signal) that is set in advance to be a master among the DRAs 100-1 to 100-3, and the DRA 100-2. When a failure occurs in the PCRF selected by ˜100-3, the CCR signal via the DRA 100-2˜100-3 is relayed.

  FIG. 2 is a diagram illustrating an example of an internal configuration of the DRA 100-1 illustrated in FIG.

  As shown in FIG. 2, the DRA 100-1 shown in FIG. 1 includes a routing unit 110, a static route management unit 111, a counter node state management unit 113, and a monitoring session management unit 114. Note that FIG. 2 shows only the components that are characteristic of this embodiment among the components provided in the DRA 100-1 shown in FIG.

  The static route management unit 111 manages the PCRFs 200-1 to 200-3 that are CCR signal transfer destinations for each subscriber. The static route management unit 111 is provided with a route management table 112.

  The path management table 112 stores PCRFs 200-1 to 200-3 as transfer destinations of CCR signals in advance for each subscriber.

  FIG. 3 is a diagram showing an example of information on the transfer destination of the CCR signal for each subscriber stored in the route management table 112 shown in FIG.

  In the route management table 112 shown in FIG. 2, subscriber identification information, PCRF identification information, and relay destination DRA identification information are stored in association with each other as shown in FIG.

  The subscriber identification information is information that can identify a subscriber uniquely assigned to the subscriber. For example, it may be a telephone number or an e-mail address.

  The PCRF identification information is information that can identify the PCRF uniquely assigned to the PCRF as the default transfer destination of the CCR signal transmitted from the subscriber to which the subscriber identification information associated with the PCRF identification information is assigned. .

  The relay destination DRA identification information is related to the case where the CCR signal transmitted from the subscriber to which the subscriber identification information associated with the relay destination DRA identification information is relayed to another DRA (master). This is information that can identify the DRA uniquely assigned to the DRA.

  The example shown in FIG. 3 will be described. Subscriber identification information “090XXXXXXXXX@aaa.ne.jp”, PCRF identification information “200-1”, relay destination DRA identification information “100-1” Are stored in association with each other. This indicates that the CCR signal transmitted from the subscriber whose subscriber identification information is “090XXXXXXXXX@aaa.ne.jp” is transferred to the PCRF whose PCRF identification information is “200-1”. Yes. Furthermore, when a failure occurs in the PCRF whose PCRF identification information is “200-1”, the CCR signal transmitted from the subscriber whose subscriber identification information is “090XXXXXXX@aaa.ne.jp” This indicates that the DRA is relayed to the DRA whose identification information is “100-1”.

  The routing unit 110 transfers the CCR signal transmitted from the S / P-GW 300 or the DRA 100-2 to 100-3 to one of the PCRFs 200-1 to 200-3. This transfer destination selection / determination will be described later.

  The opposite node state management unit 113 determines and manages whether the PCRFs 200-1 to 200-3 are available. The opposite node state management unit 113 determines that the PCRFs 200-1 to 200-3 cannot be used when a failure occurs in the PCRFs 200-1 to 200-3. Further, the opposite node state management unit 113 determines that the PCRFs 200-1 to 200-3 can be used when no failure has occurred in the PCRFs 200-1 to 200-3 (recovered from the failure). In order to detect the occurrence of a fault in the PCRFs 200-1 to 200-3, a method generally used for fault detection may be used. If it can be determined whether the PCRFs 200-1 to 200-3 are operating normally. good. For example, by monitoring whether or not a predetermined signal is transmitted from the PCRFs 200-1 to 200-3, if the signal is not transmitted, it is determined that a failure has occurred in the PCRF not transmitting the signal. It may be. In addition, when a request signal is transmitted from the opposite node state management unit 113 to the PCRFs 200-1 to 200-3, and response signals for the request signals are not returned from the PCRFs 200-1 to 200-3, the PCRFs 200-1 to 200-1 are transmitted. It may be determined that a failure has occurred in 200-3.

  FIG. 4 is a diagram illustrating an example of information managed by the opposite node state management unit 113 illustrated in FIG.

  As shown in FIG. 4, the opposite node state management unit 113 shown in FIG. 2 manages whether the PCRFs 200-1 to 200-3 can be used. PCRF identification information and its state are associated with each other and managed.

  The example shown in FIG. 4 will be described. The PCRF identification information “200-1” and the state “unusable” are associated with each other and managed. This indicates that the PCRF whose PCRF identification information is “200-1” has failed and cannot be used. Further, the PCRF identification information “200-2” and the state “available” are associated and managed. This indicates that the PCRF whose PCRF identification information is “200-2” can be used without any failure.

  The monitoring session management unit 114 associates the session identification information given to the session processing specific included in the CCR signal and the control node that is the transfer destination of the CCR signal in association with each other from the start to the end of the session processing. Manage each person. The monitoring session management unit 114 is provided with a session management table 115.

  The session management table 115 stores the session identification information included in the CCR signal and the control node that is the transfer destination of the CCR signal in association with each subscriber from the start to the end of the session process.

  FIG. 5 is a diagram showing an example of correspondence between session identification information for each subscriber stored in the session management table 115 shown in FIG. 2 and information on the transfer destination of the CCR signal.

  As shown in FIG. 5, the session management table 115 shown in FIG. 2 stores session identification information, subscriber identification information, and detour destination PCRF identification information in association with each other.

  The session identification information is information that can identify a session that is being processed, and is included in the transmitted CCR signal.

  The subscriber identification information is information that can identify a subscriber uniquely assigned to the subscriber.

  The detour destination PCRF identification information is the identification information of a PCRF that is processing a session to which session identification information associated with the detour destination PCRF identification information is assigned.

  The example shown in FIG. 5 will be described. The session identification information “01234456789”, the subscriber identification information “090XXXXXXXXX@aaa.ne.jp”, and the detour destination PCRF identification information “200-2” correspond to each other. It is attached and managed. This is because the session identification information included in the CCR signal transmitted from the subscriber whose subscriber identification information is “090XXXXXXX@aaa.ne.jp” is “01234456789” and the PCRF identification information is “200-2”. "Indicates that the PCRF is processing. Further, session identification information “1111234567”, subscriber identification information “080XXXXXXX@aaa.ne.jp”, and detour destination PCRF identification information “200-2” are associated and managed. This is because a session whose session identification information included in the CCR signal transmitted from the subscriber whose subscriber identification information is “080XXXXXXXXX@aaa.ne.jp” is “111123457” is PCRF identification information “200-2”. "Indicates that the PCRF is processing.

  In addition, the monitoring session management unit 114 searches the session management table 115 for a control node associated with the subscriber identification information included in the transmitted CCR signal as a transfer destination control node.

  When the opposite node state management unit 113 determines that the PCRF associated with the subscriber identification information included in the CCR signal and the session management table 115 cannot be used, the monitoring session management unit 114 The association between the detour destination PCRF identification information, the session identification information, and the subscriber identification information is deleted from the session management table 115.

  Hereinafter, processing for selecting and determining the transfer destination of the CCR signal in the routing unit 110 will be described.

  The routing unit 110 searches the path management table 112 for the PCRF identification information based on the subscriber identification information included in the CCR signal for the CCR signal transmitted from the S / P-GW 300, and the searched PCRF identification information. Is transferred to the PCRF. Further, the routing unit 110 detours the CCR signal transmitted from the S / P-GW 300 and the DRA 100-2 to 100-3 from the session management table 115 based on the subscriber identification information included in the CCR signal. The PCRF identification information is searched and transferred to the PCRF to which the searched detour destination PCRF identification information is assigned. When the subscriber identification information included in the CCR signals transmitted from the S / P-GW 300 and DRA 100-2 to 100-3 does not exist in the session management table 115, the opposite node state management unit 113 can be used. The selected PCRF is selected as the transfer destination control node, and the CCR signal is transferred.

  In addition, when the redirect method is used as the transfer method of the CCR signal, the routing unit 110 does not transfer the CCR signal to the PCRFs 200-1 to 200-3, generates the CCA signal for the CCR signal, and transmits the CCA signal. It transmits to the S / P-GW 300 including PCRF selection result information indicating the PCRF selection result.

  In addition, in the routing unit 110, the counter node state management unit 113 determines that the PCRF associated with the subscriber identification information in the route management table 112 is available because it is unavailable (recovered from the failure). Thereafter, when there is no subscriber identification information of the subscriber in the session management table 115, a relay release signal indicating that the relay of the CCR signal is released is transmitted to the DRA 100-2 to 100-3 that relayed the CCR signal. .

  The DRAs 100-2 to 100-3 are subordinate control node selection devices that are set in advance to be slaves to the DRA 100-1 that is the master among the DRAs 100-1 to 100-3. When a failure occurs in the PCRF selected by 100-3, the CCR signal transmitted from the S / P-GW 300 is relayed to the DRA 100-1.

  FIG. 6 is a diagram illustrating an example of an internal configuration of the DRA 100-2 illustrated in FIG. The internal configuration of the DRA 100-3 shown in FIG. 1 is the same as the internal configuration of the DRA 100-2.

  As shown in FIG. 6, the DRA 100-2 shown in FIG. 1 includes a routing unit 120, a static route management unit 121, and a counter node state management unit 123. FIG. 6 shows only the constituent elements that are characteristic of this embodiment among the constituent elements provided in the DRA 100-2 shown in FIG.

  The static route management unit 121 is the same as the static route management unit 111 shown in FIG. 2, and manages the PCRFs 200-1 to 200-3 that are CCR signal transfer destinations for each subscriber. The static route management unit 121 is provided with a route management table 122.

  The route management table 122 is the same as the route management table 112 shown in FIG.

  The opposing node state management unit 123 determines and manages whether the PCRFs 200-1 to 200-3 are available. The opposite node state management unit 123 determines that the PCRFs 200-1 to 200-3 cannot be used when a failure occurs in the PCRFs 200-1 to 200-3. Further, when the failure has not occurred in the PCRFs 200-1 to 200-3 (recovered from the failure), the opposite node state management unit 123 determines that the PCRFs 200-1 to 200-3 are available. In order to detect the occurrence of a fault in the PCRFs 200-1 to 200-3, a method generally used for fault detection may be used. If it can be determined whether the PCRFs 200-1 to 200-3 are operating normally. good. For example, by monitoring whether or not a predetermined signal is transmitted from the PCRFs 200-1 to 200-3, if the signal is not transmitted, it is determined that a failure has occurred in the PCRF not transmitting the signal. It may be. Further, when a request signal is transmitted from the opposite node state management unit 123 to the PCRFs 200-1 to 200-3, and no response signal to the request signal is returned from the PCRFs 200-1 to 200-3, the PCRF 200-1 to the PCRF 200-1 It may be determined that a failure has occurred in 200-3. This is determined and managed by the same method as the opposite node state management unit 113 shown in FIG.

  Further, the opposite node state management unit 123 determines and manages whether the DRA 100-1 is available and whether the DRA 100-1 is relaying the CCR signal. This determination as to whether or not it can be used is determined and managed in the same manner as the determination as to whether or not the PCRFs 200-1 to 200-3 can be used.

  FIG. 7 is a diagram illustrating an example of DRA information managed by the opposite node state management unit 123 illustrated in FIG.

  As shown in FIG. 7, the opposite node state management unit 123 shown in FIG. 6 manages whether the DRA 100-1 is available and whether the DRA 100-1 is relaying the CCR signal. .

  The example shown in FIG. 7 will be described as an example. The DRA identification information “100-1” and the state “available & relay OFF” are associated and managed. This indicates that a DRA having DRA identification information “100-1” can be used and is not in a state of relaying a CCR signal.

  The DRA 100-1 to 100-3 shown in FIG. 1 have both the functions of the DRA 100-1 described using FIG. 2 and the functions of the DRA 100-2 described using FIG. It doesn't matter if it is a combination.

  Below, the control node selection method in this form is demonstrated.

  First, the normal selection process in the DRA 100-1 as the master (main control node selection device) will be described.

  FIG. 8 is a sequence diagram for explaining a control node normal selection process in DRA 100-1 shown in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 or the DRA 100-2 to 100-3 is received by the routing unit 110 (step S1), based on the subscriber identification information included in the CCR signal. Then, a detour selection destination request is made from the routing unit 110 to the monitoring session management unit 114 (step S2). This requests a search for whether or not the subscriber identification information is stored in the session management table 115.

  Then, the monitoring session management unit 114 retrieves the subscriber identification information from the session management table 115 (step S3). Here, since the normal selection is performed in a state where no failure has occurred in the PCRFs 200-1 to 200-3, the subscriber identification information is not retrieved from the session management table 115. Therefore, a response “no record” is output from the monitoring session management unit 114 to the routing unit 110 (step S4).

  Subsequently, a static route is requested from the routing unit 110 to the static route management unit 111 (step S5). This requests a search from the path management table 112 for the PCRF identification information associated with the subscriber identification information included in the CCR signal received in step S1.

  Then, the static route management unit 111 searches the route management table 112 for PCRF identification information associated with the subscriber identification information (step S6). Then, as a response to the request in step S5, the searched PCRF identification information is output from the static route management unit 111 to the routing unit 110 (step S7).

  After that, in order to acquire the state of the PCRF to which the PCRF identification information output from the static route management unit 111 is added in step S7, the state acquisition specifying the PCRF identification information from the routing unit 110 is the opposite node state. Requested to the management unit 113 (step S8).

  Then, the counter node state management unit 113 searches for the state of the PCRF based on the PCRF identification information (step S9). Here, since no failure has occurred in the PCRF, a response “available” is output from the opposite node state management unit 113 to the routing unit 110 (step S10).

  Then, the PCRF assigned with the PCRF identification information is determined (selected) as the route destination (transfer destination) of the CCR signal (step S11).

  Further, when the CCR signal is relayed from the DRA 100-2 to 100-3, the subscriber identification information included in the CCR signal does not exist in the session management table 115 (the DRA 100-1 relays the CCR signal). A relay release signal indicating that the CCR signal has been relayed is then transmitted from the routing unit 110 to the DRA 100-2 to 100-3 that has relayed the CCR signal.

  Next, a new detour selection process in the DRA 100-1 as the master (main control node selection device) will be described. That is, a selection process when a failure occurs in the PCRF stored in the path management table 112 and a detour is necessary will be described.

  FIG. 9 is a sequence diagram for explaining a new detour selection process of the control node in DRA 100-1 shown in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 or the DRA 100-2 to 100-3 is received by the routing unit 110 (step S21), based on the subscriber identification information included in the CCR signal. Then, a detour selection destination request is made from the routing unit 110 to the monitoring session management unit 114 (step S22). This requests a search for whether or not the subscriber identification information is stored in the session management table 115.

  Then, the monitoring session management unit 114 searches the session management table 115 for the subscriber identification information (step S23). Here, since it is a new detour selection, the subscriber identification information is not retrieved from the session management table 115. Therefore, a response “no record” is output from the monitoring session management unit 114 to the routing unit 110 (step S24).

  Subsequently, a static route is requested from the routing unit 110 to the static route management unit 111 (step S25). This requests a search from the path management table 112 for the PCRF identification information associated with the subscriber identification information included in the CCR signal received in step S21.

  Then, the static route management unit 111 searches the route management table 112 for PCRF identification information associated with the subscriber identification information (step S26). Then, as a response to the request in step S25, the searched PCRF identification information is output from the static route management unit 111 to the routing unit 110 (step S27).

  Thereafter, in order to acquire the state of the PCRF to which the PCRF identification information output from the static route management unit 111 is added in step S27, the state acquisition specifying the PCRF identification information from the routing unit 110 is the opposite node state. Requested to the management unit 113 (step S28).

  Then, the counter node state management unit 113 searches the PCRF state based on the PCRF identification information (step S29). Here, since a failure has occurred in the PCRF, a response “unusable” is output from the opposite node state management unit 113 to the routing unit 110 (step S30).

  When a response “unusable” is output from the opposite node state management unit 113 to the routing unit 110, it is necessary to select another PCRF as the route destination (transfer destination) of the CCR signal. A detour route is requested to the node state management unit 113 (step S31). This is a request from the routing unit 110 to the counter node state management unit 113 for a search for PCRF identification information that is “available”.

  Then, the counter node state management unit 113 searches for PCRF identification information that is “available” (step S32). Then, as a response to the request in step S31, the searched PCRF identification information is output from the opposite node state management unit 113 to the routing unit 110 (step S33).

  Note that the processing in steps S31 to S33 may be performed via the static route management unit 111. For example, the request in step S31 is requested from the routing unit 110 to the static route management unit 111, and the static route management unit 111 obtains usable PCRF identification information from the opposite node state management unit 113, and the obtained PCRF identification is obtained. The information may be output from the static route management unit 111 to the routing unit 110.

  Subsequently, registration of the session identification information and subscriber identification information included in the CCR signal and the PCRF identification information output from the opposite node state management unit 113 in step S33 is performed from the routing unit 110 to the monitoring session management unit. 114 is requested (step S34).

  In the monitoring session management unit 114 requested to register, the session identification information, the subscriber identification information, and the PCRF identification information are associated with each other and registered in the session management table 115 (step S35).

  Then, a response indicating that the registration is successful is output from the monitoring session management unit 114 to the routing unit 110 (step S36), and the PCRF to which the PCRF identification information is assigned is determined as the route destination (transfer destination) of the CCR signal ( (Step S37).

  Next, a detour selection process that is already detouring in the DRA 100-1 as the master (main control node selection device) will be described.

  FIG. 10 is a sequence diagram for explaining a detour selection process during detouring of the control node in the DRA 100-1 shown in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 or DRA 100-2 to 100-3 is received by the routing unit 110 (step S41), based on the subscriber identification information included in the CCR signal. Then, a detour selection destination request is made from the routing unit 110 to the monitoring session management unit 114 (step S42). This requests a search for whether or not the subscriber identification information is stored in the session management table 115.

  Then, the monitoring session management unit 114 retrieves the subscriber identification information from the session management table 115 (step S43). Here, since the detour is already in progress, the subscriber identification information is retrieved from the session management table 115. Then, the detour destination PCRF identification information associated with the retrieved subscriber identification information and stored in the session management table 115 is acquired, and the acquired PCRF identification information is sent from the monitoring session management unit 114 as a response to step S42. The data is output to the routing unit 110 (step S44).

  After that, in order to acquire the state of the PCRF to which the PCRF identification information output from the monitoring session management unit 114 is added in step S44, the state acquisition specifying the PCRF identification information from the routing unit 110 is the opposite node state management. Requested to the unit 113 (step S45).

  Then, the counter node state management unit 113 searches the PCRF state based on the PCRF identification information (step S46). Here, since no failure has occurred in the PCRF, a response “available” is output from the opposite node state management unit 113 to the routing unit 110 (step S47).

  Subsequently, registration of the session identification information and subscriber identification information included in the CCR signal and the PCRF identification information output from the monitoring session management unit 114 in step S44 is performed from the routing unit 110 to the monitoring session management unit 114. (Step S48).

  In the monitoring session management unit 114 requested to register, the session identification information, subscriber identification information, and PCRF identification information are associated with each other and registered in the session management table 115 (step S49).

  Then, a response indicating that the registration is successful is output from the monitoring session management unit 114 to the routing unit 110 (step S50), and the PCRF to which the PCRF identification information is assigned is determined as the route destination (transfer destination) of the CCR signal ( (Step S51).

  Next, a further detour selection process for a detoured route in the DRA 100-1 as the master (main control node selection apparatus) will be described. In other words, a process will be described in the case where detouring is in progress, a failure occurs in the currently selected PCRF, and further detouring is necessary.

  FIG. 11 is a sequence diagram for explaining a further detour selection process for a detoured route of the control node in the DRA 100-1 illustrated in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 or the DRA 100-2 to 100-3 is received by the routing unit 110 (step S61), based on the subscriber identification information included in the CCR signal. Then, a detour selection destination request is made from the routing unit 110 to the monitoring session management unit 114 (step S62). This requests a search for whether or not the subscriber identification information is stored in the session management table 115.

  Then, the monitoring session management unit 114 retrieves the subscriber identification information from the session management table 115 (step S63). Here, since the detour is already in progress, the subscriber identification information is retrieved from the session management table 115. Then, the detour destination PCRF identification information associated with the retrieved subscriber identification information and stored in the session management table 115 is acquired, and the acquired PCRF identification information is sent from the monitoring session management unit 114 as a response to step S62. The data is output to the routing unit 110 (step S64).

  After that, in order to acquire the state of the PCRF to which the PCRF identification information output from the monitoring session management unit 114 is added in step S64, the state acquisition specifying the PCRF identification information from the routing unit 110 is the opposite node state management. Requested to the unit 113 (step S65).

  Then, the counter node state management unit 113 searches the PCRF state based on the PCRF identification information (step S66). Here, since a failure has occurred in the PCRF, a response of “unusable” is output from the opposite node state management unit 113 to the routing unit 110 (step S67).

  Subsequently, the subscriber identification information included in the CCR signal is specified and the session identification information associated with the subscriber identification information and the subscriber identification information and the detour destination PCRF identification information are deleted from the session management table 115. Is requested from the routing unit 110 to the monitoring session management unit 114 (step S68).

  In the monitoring session management unit 114 requested to be deleted, the subscriber identification information, session identification information, and PCRF identification information are deleted from the session management table 115 (step S69).

  Then, a response indicating that the deletion is successful is output from the monitoring session management unit 114 to the routing unit 110 (step S70).

  Subsequently, since it is necessary to select another PCRF as a route destination (transfer destination) of the CCR signal, a bypass route is requested from the routing unit 110 to the opposite node state management unit 113 (step S71). This is a request from the routing unit 110 to the counter node state management unit 113 for a search for PCRF identification information that is “available”.

  Then, the counter node state management unit 113 searches for PCRF identification information that is “available” (step S72). Then, as a response to the request in step S71, the searched PCRF identification information is output from the opposite node state management unit 113 to the routing unit 110 (step S73).

  Note that the processing in steps S71 to S73 may be performed via the static route management unit 111. For example, the request in step S71 is requested from the routing unit 110 to the static route management unit 111, and the static route management unit 111 obtains usable PCRF identification information from the opposite node state management unit 113, and the obtained PCRF identification is obtained. The information may be output from the static route management unit 111 to the routing unit 110.

  Subsequently, registration of the session identification information and subscriber identification information included in the CCR signal and the PCRF identification information output from the opposite node state management unit 113 in step S73 is performed from the routing unit 110 to the monitoring session management unit. 114 is requested (step S74).

  In the monitoring session management unit 114 requested to register, the session identification information, subscriber identification information, and PCRF identification information are associated with each other and registered in the session management table 115 (step S75).

  Then, a response indicating that the registration is successful is output from the monitoring session management unit 114 to the routing unit 110 (step S76), and the PCRF to which the PCRF identification information is assigned is determined as the route destination (transfer destination) of the CCR signal ( (Step S77).

  Next, normal selection processing in the DRA 100-2 which is a slave (subordinate control node selection device) will be described. The same applies to the normal selection process in the DRA 100-3.

  FIG. 12 is a sequence diagram for explaining a control node normal selection process in DRA 100-2 shown in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 is received by the routing unit 120 (step S81), a static route is requested from the routing unit 120 to the static route management unit 121 (step S82). ). This requests a search from the path management table 122 for the PCRF identification information associated with the subscriber identification information included in the CCR signal received in step S81.

  Then, the static route management unit 121 searches the route management table 122 for PCRF identification information and relay destination DRA identification information associated with the subscriber identification information (step S83).

  Then, the acquisition of the state of the DRA to which the searched relay destination DRA identification information is assigned is requested from the static route management unit 121 to the opposite node state management unit 123 (step S84).

  Then, a response to step S84 is output from the opposite node state management unit 123 to the static route management unit 121 (step S85). Here, since it is a normal selection process, the DRA outputs a response indicating that it is not relaying (relay OFF).

  Then, as a response to the request in step S82, the PCRF identification information searched in step S83 is output from the static route management unit 121 to the routing unit 120 (step S86).

  After that, in order to acquire the state of the PCRF to which the PCRF identification information output from the static route management unit 111 is added in step S86, the state acquisition specifying the PCRF identification information from the routing unit 120 is the opposite node state. Requested to the management unit 123 (step S87).

  Then, the counter node state management unit 123 searches the PCRF state based on the PCRF identification information (step S88). Here, since no failure has occurred in the PCRF, a response “available” is output from the opposite node state management unit 123 to the routing unit 120 (step S89).

  Then, the PCRF assigned with the PCRF identification information is determined (selected) as the route destination (transfer destination) of the CCR signal (step S90).

  In addition, after the process of step S11, S37, S51, S77, S90, when the transfer system of a CCR signal is a Proxy system, the CCR signal is transferred to the determined PCRF. When the CCR signal transfer method is the redirect method, a CCA signal is generated for the CCR signal, and the S / P-GW 300 includes PCRF selection result information indicating the PCRF for which the CCA signal is determined (selected). And the CCR signal is transmitted from the S / P-GW 300 to the PCRF.

  Next, a relay selection start process in the DRA 100-2 which is a slave (subordinate control node selection device) will be described. The same applies to the relay selection start processing in the DRA 100-3.

  FIG. 13 is a sequence diagram for explaining a relay selection start process in DRA 100-2 shown in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 is received by the routing unit 120 (step S91), a static route is requested from the routing unit 120 to the static route management unit 121 (step S92). ). This requests a search from the path management table 122 for the PCRF identification information associated with the subscriber identification information included in the CCR signal received in step S91.

  Then, the static route management unit 121 searches the route management table 122 for PCRF identification information and relay destination DRA identification information associated with the subscriber identification information (step S93).

  Then, the acquisition of the state of the DRA to which the searched relay destination DRA identification information is assigned is requested from the static route management unit 121 to the opposite node state management unit 123 (step S94).

  Then, a response to step S94 is output from the opposite node state management unit 123 to the static route management unit 121 (step S95). Here, since relay selection has not yet started, the DRA outputs a response indicating that relaying is not being performed (relay OFF).

  Then, as a response to the request in step S92, the PCRF identification information searched in step S93 is output from the static route management unit 121 to the routing unit 120 (step S96).

  Thereafter, in order to acquire the state of the PCRF to which the PCRF identification information output from the static route management unit 111 is added in step S96, the state acquisition specifying the PCRF identification information from the routing unit 120 is the opposite node state. Requested to the management unit 123 (step S97).

  Then, the counter node state management unit 123 searches for the PCRF state based on the PCRF identification information (step S98). Here, since a failure has occurred in the PCRF, a response “unusable” is output from the opposite node state management unit 123 to the routing unit 120 (step S99).

  Subsequently, since it is necessary to select DRA as the relay route of the CCR signal, the relay route is requested from the routing unit 120 to the static route management unit 121 (step S100). In this case, the routing unit 120 requests the static route management unit 121 to search for relay destination DRA identification information to be a relay route by specifying subscriber identification information included in the CCR signal.

  Then, the static route management unit 121 searches the route management table 122 for relay destination DRA identification information associated with the subscriber identification information (step S101).

  Then, the acquisition of the state of the DRA to which the searched relay destination DRA identification information is assigned is requested from the static route management unit 121 to the opposite node state management unit 123 (step S102).

  Then, a response to step S102 is output from the opposite node state management unit 123 to the static route management unit 121 (step S103). Here, since relay selection has not yet started, the DRA outputs a response indicating that relaying is not being performed (relay OFF).

  Then, a change in the DRA state is requested from the static route management unit 121 to the opposite node state management unit 123 (step S104). Specifically, the DRA state searched in step S101 is requested to be changed from “relay OFF” to “relay ON (relaying (transferring) the CCR signal)”.

  In response to the request, the DRA state is changed from “relay OFF” to “relay ON” in the opposite node state management unit 123 (step S105), and the response is changed from the opposite node state management unit 123 to the static route management unit 121. (Step S106).

  Then, as a response to step S100, the DRA identification information whose state has been changed in step S105 is output from the static route management unit 121 to the routing unit 120 (step S107).

  Then, the DRA to which the DRA identification information is assigned is determined as the route destination (transfer destination) of the CCR signal (step S108), and the CCR signal is relayed to the determined DRA.

  Next, relay selection continuation processing in the DRA 100-2 that is a slave (subordinate control node selection device) will be described. The same applies to the relay selection continuation processing in the DRA 100-3.

  FIG. 14 is a sequence diagram for explaining the relay selection continuation processing in DRA 100-2 shown in FIG.

  First, when the CCR signal transmitted from the S / P-GW 300 is received by the routing unit 120 (step S111), a static route is requested from the routing unit 120 to the static route management unit 121 (step S112). ). This requests a search from the path management table 122 for PCRF identification information associated with the subscriber identification information included in the CCR signal received in step S111.

  Then, the static route management unit 121 searches the route management table 122 for PCRF identification information and relay destination DRA identification information associated with the subscriber identification information (step S113).

  Then, the acquisition of the state of the DRA to which the searched relay destination DRA identification information is assigned is requested from the static route management unit 121 to the opposite node state management unit 123 (step S114).

  Then, a response to step S114 is output from the opposite node state management unit 123 to the static route management unit 121 (step S115). Here, since relay selection has already been performed, DRA outputs a response indicating that relaying is being performed (relay ON).

  Then, as a response to the request in step S112, the retrieved DRA identification information is output from the static route management unit 121 to the routing unit 120 (step S116).

  Then, the DRA to which the DRA identification information is assigned is determined as the route destination (transfer destination) of the CCR signal (step S117), and the CCR signal is relayed to the determined DRA.

  Next, relay selection cancellation processing in the DRA 100-2 that is a slave (subordinate control node selection device) will be described. The same applies to the relay selection cancellation processing in the DRA 100-3.

  FIG. 15 is a sequence diagram for explaining the relay selection cancellation processing in DRA 100-2 shown in FIG.

  First, when the relay release signal transmitted from the master DRA 100-1 is received by the routing unit 120 (step S121), the routing unit 120 requests the opposite node state management unit 123 to change the DRA state ( Step S122). This specifies the DRA identification information of the DRA 100-1 from the routing unit 120, and requests a change in the state of the DRA 100-1 managed by the opposite node state management unit 123.

  In the opposite node state management unit 123 requested to change the state of the DRA 100-1, the state of the DRA 100-1 is changed (step S123). Specifically, the state of the DRA 100-1 is changed from “relay ON” to “relay OFF”.

  Then, a response indicating that the change has been made is output from the opposite node state management unit 123 to the routing unit 120.

  Then, a response signal to the relay release signal received in step S121 is transmitted from the routing unit 120 to the DRA 100-1 (step S125).

  As described above, in a system in which a plurality of DRAs 100-1 to 100-3 exist, when the PCRF becomes unavailable due to a failure of the PCRF, the DRAs 100-1 to 100-3 are replaced with the substitute PCRF. Are selected by the representative master DRA, and the other slave DRAs relay the CCR signal to the master DRA. Thereby, the dynamic selection control of the route destination PCRF accompanying the failure / recovery of the PCRF can be easily performed.

  Note that the above-described processing of the DRAs 100-1 to 100-3 may be performed by a logic circuit manufactured according to the purpose. Also, a program describing the processing contents is recorded on a recording medium readable by the DRA 100-1 to 100-3, and the program recorded on the recording medium is read by the DRA 100-1 to 100-3 and executed. It may be. The recording media that can be read by the DRA 100-1 to 100-3 include transferable recording media such as a floppy disk (registered trademark), a magneto-optical disk, a DVD, and a CD, as well as the DRA 100-1 to 100-3. It refers to a memory such as ROM, RAM, HDD, etc. The program recorded on the recording medium is read by the CPU in the DRA 100-1 to 100-3, and the same processing as described above is performed under the control of the CPU. Here, the CPU operates as a computer that executes a program read from a recording medium on which the program is recorded.

100-1 to 100-3 DRA
110, 120 Routing unit 111, 121 Static route management unit 112, 122 Path management table 113, 123 Opposite node state management unit 114 Monitoring session management unit 115 Session management table 200-1 to 200-3 PCRF
300 S / P-GW

Claims (19)

A plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication, and a control node that is stored in advance in a route management table for each of the plurality of control nodes In a communication system including a plurality of control node selection devices that are selected as transfer destinations of control request signals,
The plurality of control node selection devices include a main control node selection device and a subordinate control node selection device,
The master control node selection device and the subordinate control node selection device determine whether the control node is available;
The main control node selection device is a session identification information given to session processing included in the control request signal, subscriber identification information given to the subscriber, and a transfer destination of the control request signal A session management table for storing the control node in association with the session process from start to end, and when the control request signal is transmitted, the control request signal is transmitted to the control request signal in the session management table. When the control node associated with the included subscriber identification information is searched from the session management table and the subscriber identification information included in the transmitted control request signal does not exist in the session management table, or If it is determined that the retrieved control node is not usable, the control node that is determined to be usable is controlled by the transfer destination. If the control request signal is a signal sent from the subordinate control node selection device, the control node is selected as the node. Otherwise, the control node is selected as the transfer destination control node. After determining that the control node associated with the subscriber identification information included in the request signal and the route management table is available, the subscriber identification information of the subscriber disappeared in the session management table In this case, a relay release signal indicating that is transmitted to the subordinate control node selection device,
The subordinate control node selection device further determines that the control node stored in the path management table is not usable until the relay release signal is transmitted from the main control node selection device. A communication system, wherein a control request signal transmitted from the subscriber is relayed to the main control node selection device. The communication system according to claim 1, wherein
When determining that the searched control node is not usable, the main control node selection device deletes the association between the control node, the session identification information, and the subscriber identification information from the session management table. A communication system characterized by the above. The communication system according to claim 1, wherein
The subordinate control node selection device manages whether the main control node selection device can be used, and relays the control request signal to the available main control node selection device. The communication system according to claim 3,
The subordinate control node selection device monitors the main control node selection device and determines whether the main control node selection device can be used based on whether a predetermined signal is transmitted from the main control node selection device. A communication system. The communication system according to claim 1, wherein
The control node selection device monitors the control node, and determines whether or not the control node can be used based on whether or not a predetermined signal is transmitted from the control node. A control node selection device that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication,
A routing unit for selecting the control node of the transfer destination of the control request signal;
A static route management unit that stores and manages a control node of a transfer destination of the control request signal for each subscriber in advance in a route management table;
An opposing node state manager that determines whether the control node is available;
Session identification information uniquely assigned to session processing included in the control request signal, subscriber identification information uniquely assigned to the subscriber, and a control node that is a transfer destination of the control request signal From the start to the end of this, when stored and managed in the session management table in association, when the control request signal is transmitted, subscriber identification information included in the control request signal in the session management table, A monitoring session management unit that retrieves the associated control node from the session management table;
The routing unit, when subscriber identification information included in the transmitted control request signal does not exist in the session management table, or when the control node searched by the monitoring session management unit is not available When the opposite node state management unit determines, the control node that is determined to be usable by the opposite node state management unit is selected as the transfer destination control node; otherwise, the monitoring session management unit searches When a control node is selected as the control node of the transfer destination, and the control request signal is transmitted from another control node selection device connected to the control node selection device, it is included in the control request signal When the control node associated with the subscriber identification information and the route management table is available, the opposite When the subscriber state identification information of the subscriber disappears in the session management table after the determination of the state management unit, another control node selection device that has transmitted the control request signal to the relay release signal indicating that Control node selection device that transmits to In the control node selection device according to claim 6,
The monitoring session management unit associates the control node, the session identification information, and the subscriber identification information with each other when the counter node state management unit determines that the searched control node is unavailable. A control node selection device, wherein the control node selection device is deleted from the session management table. In the control node selection device according to claim 6,
The opposite node state management unit monitors the control node and determines whether the control node is available based on whether a predetermined signal is transmitted from the control node. apparatus. A control node selection device that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication,
A routing unit for selecting the control node of the transfer destination of the control request signal;
A static route management unit that stores and manages a control node of a transfer destination of the control request signal for each subscriber in advance in a route management table;
An opposing node state manager that determines whether the control node is available;
In the routing unit, the opposite node state management unit determines that the control node stored in the route management table is not usable, and then uses another control node selection device that relays transfer of the control request signal. A control node that relays a control request signal transmitted from the subscriber to the relay control node selection device until a relay release signal indicating that the relay is released is transmitted from a relay control node selection device. Selection device. In the control node selection device according to claim 9 ,
The opposite node state management unit determines whether the relay control node selection device is available,
The control node selection device, wherein the routing unit relays the control request signal to a relay control node selection device determined to be usable by the opposite node state management unit. In the control node selection device according to claim 10 ,
The opposite node state management unit monitors the relay control node selection device and determines whether the relay control node selection device is available based on whether a predetermined signal is transmitted from the relay control node selection device. A control node selection device characterized by: In the control node selection device according to claim 9 ,
The opposite node state management unit monitors the control node and determines whether the control node is available based on whether a predetermined signal is transmitted from the control node. apparatus. A plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication, and a control node that is stored in advance in a route management table for each of the plurality of control nodes In a communication system comprising a plurality of control node selection devices that are selected as transfer destinations of control request signals, a control node that selects one control node from among the plurality of control nodes as a control node to which the control request signal is transferred A selection method,
A process for the control node selection device to determine whether the control node is available;
Of the plurality of control node selection devices, a main control node selection device includes session identification information given to session processing included in the control request signal, subscriber identification information given to the subscriber, A process of storing a control node, which is a transfer destination of the control request signal, in association with the session management table from the start to the end of the session process;
When the control request signal is transmitted, the main control node selection device searches the session management table for a control node associated with subscriber identification information included in the control request signal in the session management table. Processing to
When the main control node selection device does not have subscriber identification information included in the transmitted control request signal in the session management table, or when the searched control node is unavailable Selecting a control node determined to be usable as the transfer destination control node; otherwise, selecting the searched control node as the transfer destination control node;
In the main control node selection device, the control request signal is transmitted from a subordinate control node selection device that is a control node selection device other than the main control node selection device among the plurality of control node selection devices. If it is determined that the control node associated with the subscriber identification information included in the control request signal and the route management table is available, the subscriber identification of the subscriber is stored in the session management table. When there is no information, a process of transmitting a relay release signal indicating that to the subordinate control node selection device;
The subordinate control node selection device determines that the control node stored in the route management table is not usable until the relay release signal is transmitted from the main control node selection device. A control node selection method comprising: relaying a control request signal transmitted from a subscriber to the main control node selection device. In the control node selection method according to claim 13 ,
When the main control node selection device determines that the searched control node is unavailable, the association between the control node, the session identification information, and the subscriber identification information is deleted from the session management table. A control node selection method comprising: processing. In the control node selection method according to claim 13 ,
A process for managing whether the subordinate control node selection device can use the main control node selection device;
The control node selection method comprising: a process in which the subordinate control node selection device relays the control request signal to an available main control node selection device. The control node selection method according to claim 15 ,
A process in which the subordinate control node selection device monitors the main control node selection device;
The subordinate control node selection device has a process of determining whether or not the main control node selection device can be used based on whether or not a predetermined signal is transmitted from the main control node selection device. Control node selection method. In the control node selection method according to claim 13 ,
A process in which the control node selection device monitors the control node;
The control node selection method comprising: a process for determining whether or not the control node can be used based on whether or not a predetermined signal is transmitted from the control node. A control node selection device that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication.
A procedure for determining whether the control node is available;
Session identification information uniquely assigned to session processing included in the control request signal, subscriber identification information uniquely assigned to the subscriber, and a control node that is a transfer destination of the control request signal From the start to the end of the process, store in the session management table in association with each other,
A procedure for searching the session management table for a control node associated with subscriber identification information included in the control request signal when the control request signal is transmitted;
When subscriber identification information included in the transmitted control request signal does not exist in the session management table, or when it is determined that the searched control node is not available, it is determined that it can be used. Selecting a control node as the transfer destination control node; otherwise, selecting the searched control node as the transfer destination control node;
When the control request signal is transmitted from a control node selection device other than the control node selection device among the plurality of control node selection devices, the transfer destination of the control request signal for each subscriber After determining that the control node associated with the subscriber identification information included in the control request signal is available in the route management table that stores the control node in advance, the subscriber is stored in the session management table. And a procedure for transmitting a relay release signal indicating that to the other control node selection device that has transmitted the control request signal when there is no subscriber identification information. A control node selection device that selects one control node as a transfer destination of the control request signal among a plurality of control nodes that perform communication control based on a control request signal transmitted from a subscriber that performs communication.
A procedure for determining whether or not a control node stored in a path management table storing in advance a control node to which the control request signal is transferred for each subscriber is available;
After determining that the control node stored in the path management table is not usable, the relay is released from the relay control node selection device which is another control node selection device that relays the transfer of the control request signal. A program for causing a control request signal transmitted from the subscriber to be relayed to the relay control node selection device until a relay release signal indicating is transmitted.

Images