JP2016100749A - Communication control system and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable suitable communication control that can prevent erroneous connection or the like and is related to a communication terminal.SOLUTION: If some kind of trouble occurs, and information (table T3) indicating correspondence relation between an IP address and a communication terminal held by a P-CSCF 70 has become not in accordance with information (table T2) indicating correspondence relation between an IP address and a communication terminal held by a core-network side communication control device (PCRF 60), and an erroneous call incoming request is transmitted on the basis of information at the P-CSCF 70 side, a communication control system can prevent the call incoming request from being erroneously transmitted by a filter created by the PCRF 60 and operated by a P-GW 50, and thereby enables suitable communication control related to the communication terminal.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a communication control system and a communication control method.

  As voice communication on the LTE (Long Term Evolution) network, VoIP (Voice over LTE) service that replaces voice communication that has been conventionally performed by the circuit switching method with packet communication has been attempted. In VoLTE, when an attach signal is received from a communication terminal as defined by 3GPP (3rd Generation Partnership Project), an IP address is assigned to the communication terminal. In addition, information related to the IP address assigned to the communication terminal is shared between the exchange and the call control server related to the voice communication of the communication terminal. The IP address is released when a detach signal is received from the communication terminal (see, for example, Non-Patent Documents 1 and 2).

3GPP TS 23.228 "IP Multimedia Subsystem (IMS); Stage 2" 3GPP TS 23.401 "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access"

  However, when IP addresses are allocated and released by the conventional method, the following problems may occur. When the signal related to the release of the IP address disappears for some reason, the information related to the use of the IP address may become inconsistent between the exchange and the call control server. When such a situation occurs, for example, when there is an incoming voice call, a connection process may be performed between a communication terminal different from the assumed communication terminal.

  The present invention has been made in view of the above, and an object of the present invention is to provide a communication control system and a communication control method that can prevent erroneous connection and the like and can more suitably perform communication control related to a communication terminal. And

  In order to achieve the above object, a communication control system according to the present invention includes a core network and a call control server connected to the core network, and controls related to an incoming request to a communication terminal connected to the core network. A communication control system that performs control related to the incoming call request included in the core network, and each of the communication terminals connected to the core network. Holding the correspondence information in which the allocated IP address and the information specifying the communication terminal corresponding to the IP address are associated, and the call control server receives the incoming request to the communication terminal, Based on the correspondence information held in the call control server, information related to the incoming request is sent to the communication control device. The communication control device includes a transmission means for transmitting the information on the incoming request transmitted from the call control server on the basis of the correspondence information held in the communication control device. It is characterized by comprising verification means for determining

  The communication control method according to the present invention includes a core network and a call control server connected to the core network, and performs a control related to an incoming request to a communication terminal connected to the core network. The communication control method according to claim 1, wherein the call control server and the communication control device that is included in the core network and performs control related to the incoming request are allocated to the communication terminals connected to the core network, respectively. The correspondence information in which the specified IP address is associated with the information for identifying the communication terminal corresponding to the IP address, and the transmission means of the call control server receives an incoming call request to the communication terminal. , Based on the correspondence information held in the call control server, information related to the incoming request is The correspondence information held in the communication control device for information related to the incoming request transmitted from the call control server in the transmission step in the transmission step of transmitting to the communication control device and the verification means of the communication control device And a verification step of determining the validity of the incoming request based on the above.

  According to the communication control system and the communication control method described above, the verification means determines the validity of the incoming request based on the information related to the incoming request transmitted from the call control server. For example, an incoming request having a problem with validity can be dealt with by stopping the subsequent incoming processing. Accordingly, erroneous connection or the like can be prevented, and communication control related to the communication terminal can be more suitably performed.

  Here, as a configuration that effectively achieves the above-described operation, for example, the verification unit holds information for identifying a call control server allocated to the communication terminal that uses the IP address in association with the IP address. Based on whether or not the call control server that transmitted the information related to the incoming call request is the call control server held in association with the IP address when the information related to the incoming call request to the communication terminal is received Thus, there is a configuration for determining the validity.

  In the case of the above configuration, the validity of the incoming request is determined based on whether or not the call control server that transmitted the information related to the incoming request is a server indicated by the information that identifies the call control server held in the verification unit. Therefore, erroneous connection or the like can be prevented, and communication control related to the communication terminal can be performed more suitably.

  Further, as another configuration that effectively exhibits the above-described operation, for example, when the call control server receives an incoming call request, the transmission unit is allocated to the communication terminal held by the call control server Information related to the correspondence between the IP address and information identifying the communication terminal is transmitted to the communication control device, and the verification means holds the information transmitted from the call control server and the communication control device. There is a configuration in which the validity of the incoming call request is determined based on whether the received information matches.

  In the case of the above configuration, information related to the correspondence between the IP address assigned to the communication terminal held in the call control server that has received the incoming request and the information specifying the communication terminal is stored in the communication control device. By transmitting, it is possible to determine the legitimacy of the incoming request, so it is possible to prevent erroneous connection and the like, and it is possible to more suitably perform communication control related to the communication terminal.

  According to the present invention, there are provided a communication control system and a communication control method that can prevent erroneous connection and the like and can more suitably perform communication control related to a communication terminal.

It is a figure which shows the structure of the communication control system which concerns on 1st Embodiment. It is a figure which shows the hardware constitutions which concern on each apparatus of the communication control system which concerns on 1st Embodiment. It is a figure explaining the detachment process of the communication terminal in the communication control system which concerns on 1st Embodiment. It is a figure explaining the technical subject in the conventional communication control system. It is a figure explaining the functional block of PCRF in the communication control system concerning a 1st embodiment. It is a figure which shows an example of a filter. It is a flowchart explaining the communication control method which concerns on 1st Embodiment. It is a sequence diagram explaining the communication control method which concerns on 1st Embodiment. It is a figure explaining the functional block of PCRF in the communication control system concerning a 2nd embodiment. It is a flowchart explaining the communication control method which concerns on 2nd Embodiment. It is a sequence diagram explaining the communication control method which concerns on 2nd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a diagram illustrating a system configuration of a communication control system according to the first embodiment. A communication control system 1 shown in FIG. 1 is a communication system that provides voice communication services such as VoLTE (Voice over LTE) to communication terminals in accordance with a communication standard (communication protocol) of LTE (Long Term Evolution). . VoLTE is a service (function) for performing voice communication by packet communication, and is a function for realizing a voice call on the LTE network. In VoLTE, voice communication is performed using IMS (IP multimedia subsystem), which is a system that controls IP (Internet Protocol) -based multimedia services.

  The communication control system 1 is connectable to a communication terminal 10 (communication terminal 10A) that is a portable terminal including a smartphone and a tablet terminal, and includes an eNB (evolved Node B) 20, an MME (Mobility Management Entity) 30, S-GW (Serving Gateway) 40, P-GW (Packet data network Gateway) 50, PCRF (Policy and Charging Rules Function) 60, P-CSCF (Proxy Call Session Control Function) 70 (70A, 70B) , Including. Among these, the P-CSCF 70 is a device that performs control related to the use of a packet network (PDN) NW by the communication terminal 10A, and the other devices are devices for the communication terminal 10A to perform communication by VoLTE. It is a device constituting the core network. In providing the VoLTE, the communication control system 1 executes communication path setting and release control using SIP (Session Initiation Protocol).

  In the present embodiment, the communication control system 1 describes a case where there is an incoming request from another communication terminal to the communication terminal 10 (for example, the communication terminal 10A) connected to the core network and performs control related to the incoming request. To do.

  As shown in FIG. 2, each device included in the communication control system 1 includes a CPU 101, a RAM (Random Access Memory) 102 and a ROM (Read Only Memory) 103, which are main storage devices, and a communication module for performing communication. 104 and a computer including hardware such as an auxiliary storage device 105 such as a hard disk. And the function of each apparatus is exhibited when these components operate.

  In the communication control system 1 of the present embodiment, each device may be physically configured by a single device, or may be a processing system configured by a plurality of devices. Further, the number of components of each device may be changed to an arbitrary number.

  Returning to FIG. 1, each device included in the communication control system 1 will be described. The eNB 20 is a radio base station. That is, the eNB 20 is connected to the communication terminal 10A through wireless communication, and the admission control function when a call is transmitted from the communication terminal 10A or the communication terminal when another communication terminal receives an incoming call to the communication terminal 10A. A paging function for calling 10A is provided as a basic function. 10 A of communication terminals communicate with MME30, P-CSCF70, etc. which are the high-order apparatuses of eNB20 via eNB20. The eNB 20 performs communication control related to a plurality of communication terminals.

  The MME 30 is a call processing control device that performs network control. The MME 30 has, as basic functions, a position management function at the time of standby of the communication terminal 10A, a paging function for calling the eNB 20 when an incoming call is received from another communication terminal, and an authentication management function of the communication terminal 10A. doing.

  The S-GW 40 can be connected to the MME 30 and the eNB 2 and is further connected to the communication terminal 10A via the MME 30 and the eNB 20 to transmit an IP (Internet Protocol) packet including a control signal and user data to and from the communication terminal 10A. It is a packet gateway (relay device) that performs. Specifically, the S-GW 40 performs IP packet relay control based on an instruction from the MME 30. Further, the S-GW 40 performs IP packet transmission quality control according to QoS (Quality of Service) information notified from the PCRF 11.

  The P-GW 50 is a gateway (relay device) that is a connection point with the PDNW that is connected to the S-GW 40 and provides a data communication service such as a voice communication service such as VoLTE and an Internet connection service. The P-GW 50 can be connected to the S-GW 40, functions as an exchange that relays a connection path between the communication terminal 10A and the PDNNNW, and transfers user data. Further, the P-GW 50 performs IP packet transmission quality control according to the QoS information notified from the PCRF 11.

  The PCRF 60 can be connected to the S-GW 40 and the P-GW 50, holds information for policy control or charging control such as QoS information, and functions as an exchange that notifies the S-GW 40 and the P-GW 50 of such information. To do. This QoS information is information related to communication quality related to a communication service provided to the communication terminal 10A.

  In the communication control system in the present embodiment, the P-GW 50 and the PCRF 60 function as a communication control device that performs control related to an incoming request to the communication terminal 10 on the core network side.

  The P-CSCF 70 (70A, 70B) is a call control server that performs communication control when providing voice communication services such as VoLTE conforming to LTE to the communication terminal 10A. That is, the P-CSCF 70 can be connected to the P-GW 50 and exchanged between the communication terminal 10A and the SIP servers I-CSCF (Interrogating CSCF) and S-CSCF (Serving CSCF) existing in the PDNNNW. Relay SIP signals.

  Prior to providing the voice communication service to the communication terminal 10A, the P-CSCF 70 relay-connects the IMS bearer between the communication terminal 10A and the PDNW via the P-GW 50, the S-GW 40, and the eNB 20. The IMS bearer is a communication path for transmitting a control signal for providing a voice communication service to the communication terminal 10A. When there is an incoming call to the communication terminal 10A or an outgoing call from the communication terminal 10A, the P-CSCF 70 relays and connects an additional IMS bearer between the communication terminal 10A and the PDNW via the same communication path as the default bearer. Start voice communication. When there is an incoming call request from another communication terminal to the communication terminal 10A, the P-CSCF 70 receives an incoming call request (to the communication terminal 10A via the P-GW 50, which is one of the communication control devices on the core network side). By transmitting (incoming signal), processing related to voice communication is started. Thus, the P-CSCF 70 has a function as a transmission unit that transmits an incoming request to the core network side.

  The P-CSCF 70 is provided for each different voice communication service. Therefore, the P-CSCF 70 to be connected may be different for each communication terminal that receives the voice communication service. In the present embodiment, a case where the communication terminal 10A is connected to the P-CSCF 70A will be described. A case where a communication terminal 10B (described later) different from the communication terminal 10A is connected to the P-CSCF 70B will be described.

  The communication terminal 10A is a terminal device used by a user, and is realized by, for example, a smartphone, a tablet, or the like. As information for specifying the communication terminal 10A, for example, IMSI (International Mobile Subscriber Identity) for identifying the user of the communication terminal is known. In the communication control system 1, desired processing such as voice communication related to the communication terminal 10A is realized using information for specifying the communication terminal 10A.

  Next, processing conventionally performed in the communication control system 1 and problems of the prior art will be described. First, a case where the communication terminal 10A performs an attach process such as power-on will be described with reference to FIG. This is an existing process conventionally performed.

  When the communication terminal 10A performs the attach process, first, the communication terminal 10A requests the communication control system 1 to connect an IMS bearer (S01). The IMS bearer connection request is transmitted from the communication terminal 10A to the P-GW 50 via the eNB 20, the MME 30, and the S-GW 40. When receiving the IMS bearer connection request from the communication terminal 10A, the P-GW 50 determines an IP address to be paid out to the communication terminal 10A (or the user A who is the user) (S02). This IP address is used as information for specifying the communication terminal 10A when transmitting / receiving a packet related to voice communication, and is issued in association with, for example, IMSI. The P-GW 50 pays out IP-A as an IP address corresponding to the user A who is the user of the communication terminal 10A, and holds information related to the correspondence (correspondence information) as a table T1.

  Next, the P-GW 50 notifies the PCRF 60 of information related to the IP address used by the communication terminal 10A (user A) (S03). Thereby, in the PCRF 60, the same information (correspondence information) as the table T1 in the P-GW 50 is held as the table T2. Thereafter, the P-GW 50 notifies the communication terminal 10A (user A) that the processing related to establishment of the IMS bearer has been performed, and the IP address (IP assigned to the communication terminal 10A (user A)) -A) is notified (S04). Thereafter, the communication terminal 10A (user A) requests the P-CSCF 70A for a register related to the own terminal (user) (S05). The P-CSCF 70A performs register processing based on a request from the communication terminal 10A (user A), and also associates information for identifying the communication terminal 10A (user A) with an IP address (correspondence information) ) Is held as a table T3 (S06). Thereby, the process for the communication terminal 10A (user A) to perform voice communication ends. When there is a connection request for the communication terminal 10A, the P-CSCF 70A relays and connects an additional IMS bearer for voice communication with the communication terminal 10A based on the connection request, and then performs voice communication. Do. Thus, information (correspondence information) indicating the correspondence between the information specifying the communication terminal 10A (user A) and the IP address assigned to the communication terminal 10A is the P-GW50, PCRF60, and P-CSCF70A. They are shared by maintaining a common correspondence table.

  Next, with reference to FIG. 3, a case where the communication terminal 10 </ b> A performs a detaching process such as a case where the power is turned off or the terminal is moved out of the service area will be described. This is an existing process conventionally performed.

  It is assumed that the communication terminal 10A is out of service area by the user A turning off the power supply of the communication terminal 10A. At this time, the communication terminal 10A transmits an execution request for the detach process (S11). The execution request for the detach process from the communication terminal 10A is transmitted from the communication terminal 10A to the P-GW 50 via the eNB 20, the MME 30, and the S-GW 40. When the P-GW 50 receives the execution request for the detach process from the communication terminal 10A, the P-GW 50 deletes information related to the communication terminal 10A (user A) in the table T1 held by the own device (S12). In FIG. 3, the fact that the information related to user A has been deleted is indicated by shading the items in the table.

  Further, a release signal related to the communication terminal 10A is transmitted from the P-GW 50 to the PCRF 60 (S13). The PCRF 60 deletes information related to the communication terminal 10A (user A) in the table T2 based on the release signal (S14). Also, a release signal is transmitted from the PCRF 60 to the P-CSCF 70A (S15). Then, the P-CSCF 70A deletes information related to the communication terminal 10A (user A) in the table T3 based on the release signal (S16). In this way, signals related to the detach process of the communication terminal 10A are notified to the P-GW 50, the PCRF 60, and the P-CSCF 70A in this order, so that they are assigned to the communication terminal 10A (user A) and the communication terminal 10A. The information related to the correspondence relationship with the IP address is deleted in each device. After the detach process is performed in this manner, the IP address (IP-A) used for the communication terminal 10A (user A) can be allocated to another communication terminal.

  Here, as shown in FIG. 4, a problem occurs in communication between the PCRF 60 and the P-CSCF 70A for some reason during communication related to the detach process of the communication terminal 10A (user A). Assume that no release signal is transmitted from the PCRF 60 to the P-CSCF 70A. In this case, as shown in FIG. 4, in the P-GW 50 and the PCRF 60, the correspondence between the communication terminal 10A (user A) and the IP address (IP-A) is determined based on the execution request for the detach process from the communication terminal 10A. While the P-CSCF 70A does not receive the release signal related to the communication terminal 10A, the communication terminal 10A (user A) and the IP address (IP-A) are discarded. ) Is not discarded (see table T3). For this reason, inconsistency of information relating to the communication terminal 10A (user A) occurs among the three of the P-GW 50, the PCRF 60, and the P-CSCF 70A. When such a situation occurs, the following problems may occur.

  First, the P-CSCF 70A recognizes that the communication terminal 10A (user A) is in a state capable of voice communication because the table T3 includes information related to the communication terminal 10A (user A). Therefore, when there is an incoming call request (voice communication request) addressed to the communication terminal 10A to the P-CSCF 70A, the P-CSCF 70A may perform normal voice communication start processing. In this case, the PCRF 60 and the P-GW 50 side recognize that the communication terminal 10A has been detached, and an error may occur.

  Note that FIG. 4 illustrates the table mismatch between the P-CSCF 70A and the PCRF 60 and P-GW 50 due to the fact that the release signal has not been transmitted from the PCRF 60 to the P-CSCF 70A. Also, there may be a table mismatch when a release signal cannot be transmitted from the P-GW 50 to the PCRF 60 for some reason. In this case, the PCRF 60 recognizes a communication error with the P-GW 50 and deletes the information held in the own apparatus, but the PCRF 60 does not transmit a release signal to the P-CSCF 70A. For this reason, the P-CSCF 70A does not discard the correspondence between the communication terminal 10A (user A) and the IP address (IP-A), and there is a table mismatch between the P-CSCF 70A and the PCRF 60 and P-GW 50. It can happen.

  The second point is that there is a possibility that an incoming call request (voice communication request) addressed to the communication terminal 10A may be connected to another communication terminal. As described above, since the IP address after performing the detach process can be allocated to another communication terminal, the IP address allocated to the communication terminal 10A (user A) is newly attached. There is a case where it is allocated to the communication terminal 10B (user B) that has transmitted the request. Here, as shown in FIG. 4, it is assumed that the IP address (IP-A) used by the communication terminal 10A is allocated to the communication terminal 10B that receives the provision of the service from the P-CSCF 70B.

  In this case, in the P-GW 50 and the PCRF 60, the IP address (IP-A) is allocated to the communication terminal 10B (user B) after the information related to the communication terminal 10A (user A) is deleted. Therefore, the correspondence between the communication terminal 10B (user B) and the IP address (IP-A) is held (see tables T1 ′ and T2 ′). Moreover, since the PCRF 60 notifies the IP address to the P-CSCF 70B relating to the service received by the communication terminal 10B (user B), the P-CSCF 70B also holds the same information as the tables T1 ′ and T2 ′ ( (See Table T4). On the other hand, since the P-CSCF 70A does not provide a service to the communication terminal 10B, the P-CSCF 70A is not notified of information on the communication terminal 10B newly associated with the IP address (IP-A). When the communication terminal 10A and the communication terminal 10B use a service provided from the same P-CSCF 70A, when the communication terminal 10B makes a register request to the P-CSCF 70A (S05 in FIG. 1), the IP Since the address is duplicated, an error can be recognized on the P-CSCF 70A side. However, when register requests are transmitted to different P-CSCFs 70A and 70B, it is difficult to notice duplication of IP addresses because the P-CSCFs 70A and 70B perform processing related to the registers.

  In such a case, if the P-CSCF 70A receives an incoming request for the communication terminal 10A, the P-CSCF 70A transmits a connection request with the communication terminal specified by the IP address (IP-A). On the other hand, the P-GW 50 and the PCRF 60 refer to the table held by the own device and start processing related to connection to the communication terminal 10B associated with IP-A. In this case, there is a possibility that voice communication with the communication terminal 10B may be performed even though the incoming request to the communication terminal 10A is transmitted. In this way, if the information regarding the correspondence relationship between the IP address and the communication terminal held on the P-CSCF 70A side, the P-GW 50 and the PCRF 60 side is different from each other, there is a possibility that an erroneous connection may occur. There was a technical problem.

  In the communication control system 1 according to the present embodiment, the PCRF 60 and the P-GW 50 verify the legitimacy of the incoming request received by the P-CSCF 70 as a configuration that does not cause an erroneous connection to the above technical problem. It is characterized by that. Specifically, the PCRF 60 has a filter creation unit as a function for preventing erroneous connection, and the P-GW 50 operates the filter created by the filter creation unit.

  In the communication control system 1 according to the present embodiment, the PCRF 60 includes a call control signal transmission / reception unit 61, a profile management unit 62, and a filter creation unit 63, as shown in FIG.

  The call control signal transmission / reception unit 61 has a function of transmitting / receiving a control signal to / from the S-GW 40, the P-GW 50, and the P-CSCF 70. Further, the profile management unit 62 has a function of holding a correspondence relationship between information (for example, IMSI) for specifying a communication terminal and an IP address as a table T2 shown in FIG. Further, the filter creation unit 63 has a function of creating a filter used in the P-GW 50.

  The filter created by the filter creation unit 63 is information in which a communication terminal 10 to which an IP address is assigned is associated with information specifying the P-CSCF 70 that receives the service, and is based on the filter. It is determined whether or not the subsequent processing may be performed. Specifically, as shown in FIG. 6, as a filter for IP-A, the transmission source address for transmitting an incoming request received by the P-GW 50 is information (P-CSCF (B)) that identifies the P-CSCF 70B. In some cases, information indicating that the incoming request can be transmitted to the communication terminal, and the source address for transmitting the incoming request received by the P-GW 50 identifies the P-CSCF 70B (P-CSCF (B)) ) (Other addresses), it is indicated that the incoming request cannot be transmitted to the communication terminal. In the attach process related to the communication terminal, the filter is a target to which the communication terminal requests the register in the PCRF 60 when performing the process related to the register request to the P-CSCF 70 transmitted from the communication terminal (S05 in FIG. 1). The information specifying the P-CSCF 70 is acquired and created based on this information. In the case of the filter shown in FIG. 6, when the communication terminal 10B makes a register request to the P-CSCF 70B, the PCRF 60 obtains information on the P-CSCF 70B and assigns an IP address (IP-A) assigned to the communication terminal 10B. Created by associating.

  FIG. 6 shows an example in which the “destination address” column is “* (all)” and filtering related to the destination address is not performed, but the destination address of the incoming request (for example, , Information for specifying the communication terminal 10B) can also be a constituent element of the filter.

  In this way, the filter creation unit 63 creates a filter, transmits it to the P-GW 50, and operates the filter in the P-GW 50, so that communication different from the communication terminal to which the IP address is allocated in the P-GW 50 and the PCRF 60. When there is an incoming call request to the terminal, it is possible to prevent erroneous connection to the communication terminal to which the IP address is assigned. That is, the filter creation unit 63 and the P-GW 50 function as verification means for the communication control device included in the core network.

  In the present embodiment, a configuration for performing a determination using a filter in the P-GW 50 will be described. However, in addition to the P-GW 50, a configuration in which the filter is also used in the S-GW 40 is preferable. In this case, for example, even if the filter cannot be operated in the P-GW 50 for some reason, the filter can be operated in the S-GW 40, so that the effect of preventing erroneous connection can be enhanced. When the S-GW 40 is configured to operate the filter, the S-GW 40 also functions as a verification unit for the communication control device included in the core network. In the following communication control method, a configuration in which a filter is applied to the S-GW 40 and a determination using the filter information is performed in the P-GW 50 will be described.

  The communication control method using the filter in the communication control system 1 will be further described with reference to the flowchart shown in FIG. First, the communication terminal 10 starts an attach process (S21). At this time, the filter creation unit 63 of the PCRF 60 notifies the filter information to the P-GW 50 and the S-GW 40 (S22). The filter information is information for operating the filter in the P-GW 50 and S-40, and includes information for specifying the communication terminal 10 and information for specifying the P-CSCF 70 to which the communication terminal 10 is connected. Thereafter, the communication terminal 10 completes the attach process (S23). Thereafter, when the IP address assigned to the communication terminal 10 (this address is used as a destination address included in the incoming request) is also used as a filter, the IP address is used as filter information for the P-GW 50 and S-40. (S24) may be configured. Through the processing so far, the information related to the filters used in the P-GW 50 and S-40 is transmitted to the P-GW 50 and S-40.

  Thereafter, when the P-CSCF 70 receives an incoming request from another communication terminal, the incoming signal is transmitted from the P-CSCF 70 to the P-GW 50 (S25). Here, in the P-GW 50, it is determined whether information included in the incoming signal (information related to the transmission source P-CSCF 70 and the transmission destination address) matches the filter information held in the P-GW 50. (S26). If it matches the filter information, the process related to the incoming call is performed (S27). On the other hand, if it does not match the filter information, the incoming signal from the P-CSCF 70 is assumed to be illegal and the incoming signal is discarded (S28). As a result, even if it is not possible to notify the P-CSCF 70 of the update of the information related to the IP address assigned to the communication terminal, the P-CSCF 70 determines whether or not the incoming signal can be connected from the unregistered P-CSCF 70. Since it can be determined in the GW 50, erroneous connection can be prevented.

  The communication control method will be described with reference to the sequence diagram shown in FIG. When an IMS bearer establishment request is transmitted from the communication terminal 10 to the MME 30 (S31), an attach process, that is, a process related to the IMS bearer establishment starts. At this time, when the IMS bearer establishment request (S32) is transmitted from the S-GW 40 to the PCRF 60, the P-CSCF 70 to which the communication terminal 10 is connected is selected in the PCRF 60 (S33), and the filter is created in the filter creation unit 63. It is created (S34). Here, filter creation means that information to be notified to the S-GW 40 is extracted as filter information. Thereafter, the filter information is notified from the PCRF 60 to the S-GW 40 (S35), and the filter is applied in the S-GW 40 (S36). Similarly, when the IMS bearer establishment request (S37) is transmitted from the P-GW 50 to the PCRF 60, the filter information is notified from the PCRF 60 to the P-GW 50 (S38). A filter is applied (S39). Note that the order of the processing (S35, S36) related to the filter application in the S-GW 40 and the processing (S38, S39) related to the filter application in the P-GW 50 may be reversed. That is, with a configuration in which a filter is created after receiving an IMS bearer establishment request from the S-GW 40 or the P-GW 50, the filter information is notified to the S-GW 40 and the P-GW 50, and the filter is applied to both devices. I just need it.

  When the destination address of the communication terminal 10 is used in the filter, the IMS location registration request / response processing is performed between the communication terminal 10 and the P-CSCF 70 (S40), and then the IMS location registration is performed. Is notified from the P-CSCF 70 to the PCRF 60 (S41), the filter creation unit 63 of the PCRF 60 stores that the information of the address of the communication terminal 10 (address used as the transmission destination address) is used as a filter. At the same time, the information is notified to the S-GW 40 as a filter change request (S42). The S-GW 40 changes the filter based on the filter change request (S43). The filter change request is also notified to the P-GW 50 (S44). The P-GW 50 changes the filter based on the filter change request (S45). Similar to the process related to filter application, the order of the process related to the filter change in the S-GW 40 (S42, S43) and the process related to the filter change in the P-GW 50 (S44, S45) are reversed. May be.

  Here, it is assumed that there is an incoming call request to a P-CSCF 70 different from the P-CSCF 70 with which the communication terminal 10 has performed IMS location registration (S46). In this case, the P-CSCF 70 that has received the incoming request transmits the incoming request as an incoming signal to the P-GW 50 (S47: transmission step). At this time, the P-GW 50 determines whether the incoming signal is appropriate using a filter (S48: verification step). As shown in FIG. 7, when the information included in the incoming signal does not match the filter information, the incoming signal is discarded. Therefore, since the subsequent processing is not performed, the P-CSCF 70 determines that a timeout has occurred based on the fact that the response from the P-GW 50 is not returned (S49), and the terminal that has transmitted the incoming call request It is notified that the incoming call is NG (an error has occurred) (S50).

  As described above, in the communication control system according to the present embodiment, information indicating the correspondence between the IP address held in the P-CSCF 70 (call control server) and the communication terminal due to some failure or the like (for example, the table T3), the core The IP address held in the PCRF 60, which is one of the network side communication control devices, and the information indicating the correspondence between the communication terminals (for example, the table T2) are inconsistent, and erroneously based on the information on the P-CSCF 70 side. Even if the incoming call request is transmitted, the filter created in the PCRF 60 and operated in the P-GW 50 can prevent the incoming call request from being erroneously transmitted, and communication control related to the communication terminal is more suitable. Can be performed.

(Second Embodiment)
Next, a communication control system according to the second embodiment of the present invention will be described. The communication control system according to the second embodiment is different from the communication control system according to the first embodiment as follows. In other words, in the first embodiment, the filter created in the PCRF 60 is operated in the P-GW 50 to confirm whether the incoming request (incoming signal) is appropriate. In the second embodiment, In the PCRF 60, the validity of the incoming request (incoming signal) is confirmed.

  FIG. 9 shows a functional block diagram of the PCRF 60A in the communication control system according to the second embodiment. As illustrated in FIG. 9, the PCRF 60A includes an information comparison unit 64 instead of the filter creation unit 63 in the PCRF 60 according to the first embodiment. The information comparison unit 64 has a function of comparing the information held in the profile management unit 62 with the information sent from the P-CSCF 70 upon receipt of the incoming call request and determining whether they match. If the two match, the process related to the incoming call request is continued. On the other hand, if the two do not match, it is determined as an error and the process related to the incoming call is stopped. Thereby, it is possible to prevent erroneous connection to the communication terminal 10. That is, the information comparison unit 64 functions as a verification unit for the communication control device included in the core network.

  The communication control method in the communication control system according to the second embodiment will be further described with reference to the flowchart shown in FIG. First, the communication terminal 10 starts an attach process (S61). At this time, in the PCRF 60, the profile management unit 62 holds information for specifying the communication terminal and the IP address assigned to the communication terminal (S62). Thereafter, the communication terminal 10 completes the attach process (S63).

  When the P-CSCF 70 receives an incoming request from another communication terminal, the information stored in the own server is transmitted from the P-CSCF 70 to the PCRF 60 as the incoming request is received (S65). ). Here, the information transmitted from the P-CSCF 70 in relation to the incoming call request includes information for specifying the communication terminal 10 and the IP address of the communication terminal 10. This is information corresponding to the table T3 shown in FIG. That is, the P-CSCF 70 makes an inquiry to the PCRF 60 as to whether or not the subsequent processing can be executed using the information held by the own device. The information comparison unit 64 of the PCRF 60 compares the information transmitted from the P-CSCF 70 with the information held in the profile management unit 62 of the PCRF 60, and determines whether they match (S66). If the information matches the information held in the profile management unit 62, processing related to the incoming call is performed (S67). On the other hand, if the information does not match the information held in the profile management unit 62, the incoming request received by the P-CSCF 70 is not valid (a problem may occur if the subsequent processing is continued). The P-CSCF 70 is notified of the error, and error processing is performed (S68). Thereby, even if an update of information related to the IP address assigned to the communication terminal has not been notified to the P-CSCF 70 and an invalid incoming request is received, the PCRF 60 verifies the validity and thereafter Since the above process can be performed, erroneous connection can be prevented.

  The communication control method will be described with reference to the sequence diagram shown in FIG. First, an IMS bearer establishment request is transmitted from the communication terminal 10 to the MME 30, whereby an attach process, that is, a process related to IMS bearer establishment is performed (S71). Here, it is assumed that there is an incoming call request to the P-CSCF 70 (S72). The P-CSCF 70 that has received the incoming request transmits an incoming subscriber check request to the PCRF 60 (S73: transmission step). The incoming subscriber check request includes information included in the table T3 of FIG. 1, that is, information for specifying a connection destination communication terminal, and an IP address. The information comparison unit 64 of the PCRF 60 compares the information transmitted from the P-CSCF 70 with the information held in the profile management unit 62 to determine whether they match (S74: verification step). Here, as shown in FIG. 10, when the information transmitted from the P-CSCF 70 does not match the information held in the profile management unit, an error response is returned (S75). Thereby, the P-CSCF 70 notifies the terminal that has transmitted the incoming call request that the incoming call is NG (an error has occurred) (S76). On the other hand, when the information transmitted from the P-CSCF 70 matches the information held in the profile management unit, an OK response is returned to the P-CSCF 70 (S77). Thereby, the P-CSCF 70 transmits an incoming call request (incoming signal) to the communication terminal 10 (S78), and continues the incoming call process (S79).

  As described above, in the communication control system according to the present embodiment, information (table T3) indicating the correspondence relationship between the IP address held in the P-CSCF 70 (call control server) and the communication terminal due to some failure or the like, the core network The information (for example, table T2) indicating the correspondence relationship between the IP address held in the PCRF 60, which is one of the communication control devices on the side, and the communication terminal becomes inconsistent, and is incorrect based on the information on the P-CSCF 70 side. Even if the incoming request is transmitted, the validity of the incoming request can be verified by determining whether the information transmitted from the P-CSCF 70 in the PCRF 60 matches the information held in the profile management unit 62 of the own device. To be judged. As a result, it is possible to prevent the incoming request from being erroneously sent, and it is possible to more suitably perform communication control related to the communication terminal.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be modified in various ways as described below without departing from the scope of the invention.

  For example, in the above embodiment, the configuration in which the filter is created in the PCRF 60 and the filter is operated in the P-GW 50 has been described. However, for example, the creation and operation of the filter may be performed in the same apparatus. Further, one communication control apparatus may execute all the processes related to filter creation and operation on the core network side, and the apparatus configuration can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Communication control system, 10 ... Communication terminal, 20 ... eNB, 30 ... MME, 40 ... S-GW, 50 ... P-GW, 60 ... PCRF, 70 ... P-CSCF.

Claims (4)

A communication control system configured to include a core network and a call control server connected to the core network, and to perform control related to an incoming request to a communication terminal connected to the core network,
The call control server and a communication control device included in the core network and performing control related to the incoming call request are respectively assigned an IP address and the IP address assigned to the communication terminal connected to the core network Holding correspondence information associated with information identifying a communication terminal corresponding to,
The call control server, when receiving an incoming request to the communication terminal, based on the correspondence information held in the call control server, transmits information related to the incoming request to the communication control device With
The communication control device includes verification means for determining the validity of the incoming call request based on the correspondence information held in the communication control device for information related to the incoming call request transmitted from the call control server. , Communication control system.   The verification means retains information for specifying a call control server allocated to the communication terminal that uses the IP address in association with the IP address, and receives information related to an incoming request to the communication terminal The communication control system according to claim 1, further comprising: determining whether the call control server that has transmitted the information related to the incoming call request is a call control server held in association with the IP address. . When the call control server receives an incoming call request, the transmission means has a correspondence relationship between an IP address assigned to the communication terminal held by the call control server and information identifying the communication terminal. Sending such information to the communication control device,
The communication control according to claim 1, wherein the verification unit determines the validity of the incoming request based on whether information transmitted from the call control server matches information held in the communication control device. system. A communication control method by a communication control system configured to include a core network and a call control server connected to the core network, and to perform control related to an incoming request for a communication terminal connected to the core network,
The call control server and a communication control device included in the core network and performing control related to the incoming call request are respectively assigned an IP address and the IP address assigned to the communication terminal connected to the core network Holding correspondence information associated with information identifying a communication terminal corresponding to,
When the transmission unit of the call control server receives an incoming request to the communication terminal, the information related to the incoming request is transmitted to the communication control device based on the correspondence information held in the call control server. Sending step to
In the verification means of the communication control device, the validity of the incoming call request based on the correspondence information held in the communication control device for information related to the incoming call request transmitted from the call control server in the transmission step A verification step for determining
A communication control method comprising:

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