Network device, method, and program

Abstract

A policy management function unit (11) in a network device (10) notifies, upon reception of a control signal transmitted from a session management function unit which has received a connection instruction (e.g., Attach, etc.) of a terminal, a policy for the terminal to a LAN positioned between a core network and the internet. Specifically, the policy management function unit (11) notifies the policy to the LAN through a TCP-based interface or an STCP-based interface. In addition, the policy management function unit (11) receives the control signal through the TCP-based interface or the STCP-based interface.

Description

[Technical field]

[0001] The present disclosure relates to a network device, a method, and a non-transitory computer-readable medium having a program stored thereon. [Background technology]

[0002] In an EPC (Evolved Packet Core), a P-GW (Packet Data Network Gateway) is provided as a component (functional unit) that transfers user packets between the EPC and the external Internet (see, for example, Patent Document 1). A Gi-LAN (Local Area Network) is provided between the EPC and the Internet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-92542 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, the EPC is provided with a PCRF (Policy and Charging Rules Function) as a function unit (policy management function unit) that manages policies. Then, when the P-GW receives a connection instruction (such as Attach) for the UE (User Equipment) transmitted from the MME (Mobility Management Entity) via the S-GW (Serving Gateway), the P-GW transmits a connection instruction to the Gi-LAN. Then, when the Gi-LAN receives the connection instruction from the P-GW, it executes a procedure for acquiring a policy from the PCRF. This policy is defined in a contract between the user and the carrier.

[0005] However, the protocol used when the P-GW sends a connection instruction to the Gi-LAN is the de facto standard, Radius (Remote Authentication Dial In User Service). Radius uses UDP (User Datagram Protocol) and is therefore unreliable. For this reason, the connection instruction sent by the P-GW to the Gi-LAN may not reach the Gi-LAN, and as a result, the policy may not be notified to the Gi-LAN from the PCRF. In this case, the policy may not be reflected in the Gi-LAN, and either the user or the carrier may suffer disadvantages related to billing. This problem may occur not only in the EPC, but also in the core network of the 5G system (5G core (5GC)) and in a network where the EPC and 5GC coexist. Here, the MME, P-GW, and S-GW (Serving Gateway) of the EPC correspond to the SMF (Session Management Function) and AMF (Access and Mobility Management Function) of the 5GC, and the PCRF of the EPC corresponds to the PCF (Policy control Function) of the 5GC.

[0006] An object of the present disclosure is to provide a network device, a method, and a non-transitory computer-readable medium having a program stored thereon, which can reliably reflect policies in a LAN located between a core network and the Internet. [Means for solving the problem]

[0007] A network device according to a first aspect is a network device of a core network, A policy management function unit that manages a policy of the terminal; The policy management function unit is When a control signal transmitted from a session management function unit that has received a connection instruction for the terminal is received via a TCP (Transmission Control Protocol)-based interface or an SCTP (Stream Control Transmission Protocol)-based interface, the policy is notified to a LAN (Local Area Network) located between the core network and the Internet via the TCP-based interface or the SCTP-based interface.

[0008] A method according to a second aspect is a method executed by a network device of a core network, the network device includes a policy management function unit that manages a policy of a terminal; The method includes, when the policy management function unit receives a control signal from a session management function unit that has received a terminal connection instruction via a TCP (Transmission Control Protocol)-based interface or an SCTP (Stream Control Transmission Protocol)-based interface, notifying the policy to a LAN (Local Area Network) located between the core network and the Internet via the TCP-based interface or the SCTP-based interface.

[0009] A non-transitory computer-readable medium according to a third aspect is a non-transitory computer-readable medium storing a program for causing a network device of a core network to execute a process, the network device includes a policy management function unit that manages a policy of a terminal; The processing includes notifying a LAN (Local Area Network) located between the core network and the Internet of the policy via a TCP (Transmission Control Protocol)-based interface or a SCTP (Stream Control Transmission Protocol)-based interface when the policy management function unit receives a control signal from a session management function unit that has received a terminal connection instruction, via a TCP (Transmission Control Protocol)-based interface or an SCTP (Stream Control Transmission Protocol)-based interface. Effect of the Invention

[0010] The present disclosure makes it possible to provide a network device, a method, and a non-transitory computer-readable medium having a program stored thereon, which can reliably reflect policies in a LAN located between a core network and the Internet. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a block diagram showing an example of a network device of a core network in the first embodiment. [Diagram 2] 1 is a schematic diagram of a 5G core. [Diagram 3] A block diagram showing an example of a 5G core network device in the second embodiment. [Figure 4] A sequence diagram for explaining the processing operation of a 5G core network device in the second embodiment. [Diagram 5] FIG. 1 is a schematic diagram of an EPC. [Figure 6] A block diagram showing an example of a network device of an EPC in the third embodiment. [Figure 7] FIG. 13 is a sequence diagram illustrating the processing operation of a network device of an EPC in the third embodiment. [Figure 8] FIG. 2 illustrates an example of a hardware configuration of a network device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment will be described with reference to the drawings. In the embodiments, the same or equivalent elements are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0013] First Embodiment 1 is a block diagram showing an example of a network device of a core network in the first embodiment. In FIG.

[0014] The policy management function unit 11 manages the policy of a terminal (not shown). For example, when the policy management function unit 11 receives a control signal transmitted from a session management function unit (not shown) that has received a connection instruction (e.g., Attach, etc.) of the terminal (not shown), the policy management function unit 11 notifies a "LAN (Local Area Network)" (not shown) located between a core network and the Internet of the policy for the terminal (not shown). Specifically, the policy management function unit 11 may notify the "LAN (Local Area Network)" of the policy via a TCP (Transmission Control Protocol)-based interface or an SCTP (Stream Control Transmission Protocol)-based interface. This LAN is sometimes called a Gi-LAN.

[0015] Incidentally, the policy management function unit 11 normally receives the above control signal via a TCP (Transmission Control Protocol) based interface or an SCTP (Stream Control Transmission Protocol) based interface.

[0016] Here, it is also conceivable that the session management function unit (not shown) transmits a control signal to the Gi-LAN using Radius (Remote Authentication Dial In User Service), and in response to this control signal, the Gi-LAN executes a procedure for acquiring a policy from the policy management function unit 11. However, Radius uses UDP (User Datagram Protocol), and is therefore unreliable. For this reason, the connection instruction transmitted by the P-GW to the Gi-LAN may not reach the Gi-LAN, and as a result, the policy may not be notified to the Gi-LAN from the PCRF. In this case, the policy may not be reflected in the Gi-LAN, and either the user or the carrier may suffer a disadvantage in terms of billing.

[0017] In response to this, the policy management function unit 11 in the network device 10 notifies the Gi-LAN of a policy for the terminal (not shown) when it receives a control signal transmitted from a session management function unit (not shown) that has received a connection instruction (e.g., Attach, etc.) for the terminal (not shown). The policy management function unit 11 receives the above control signal via a TCP (Transmission Control Protocol)-based interface or an SCTP (Stream Control Transmission Protocol)-based interface. In addition, the TCP-based interface or the SCTP-based interface is used for this notification. In this way, the policy management function unit 11 notifies the Gi-LAN of a policy for the terminal (not shown) via a protocol-based interface that ensures the reliability of communication, triggered by receiving a control signal from the session management function unit (not shown) via a protocol-based interface that ensures the reliability of communication, so that the policy can be reliably reflected in the Gi-LAN.

[0018] <Second embodiment> The second embodiment relates to a more specific embodiment. In particular, the second embodiment describes a case where the core network is a core network of a 5G system (5G core (5GC)).

[0019] <5G Core Overview> Fig. 2 is a schematic diagram of a 5G core. In Fig. 2, a 5G core 20 includes an access and mobility management function (AMF) 21, a session management function (SMF) 22, and a policy control function (PCF) 23.

[0020] The AMF 21 is a functional unit that performs registration management, connection management, and mobility management.

[0021] The SMF 22 is a functional unit that performs session management.

[0022] The PCF 23 is a functional unit that manages policies and rules.

[0023] As shown in FIG. 2, a Gi-LAN 30 is provided between the 5G core 20 and the Internet 40.

[0024] <Network device configuration example> Fig. 3 is a block diagram showing an example of a network device of a 5G core in the second embodiment. In Fig. 3, a network device 50 has a policy management function unit 51. The policy management function unit 51 corresponds to the PCF 23 in Fig. 2.

[0025] Similar to the policy management function unit 11 of the first embodiment, the policy management function unit 51 notifies the Gi-LAN 30 of a policy for a terminal (not shown) when it receives a control signal transmitted from a session management function unit (corresponding to the above-mentioned SMF 22) which has received a connection instruction (e.g., Attach, etc.) for the terminal (not shown). Specifically, the policy management function unit 51 notifies the Gi-LAN 30 of this policy via a TCP (Transmission Control Protocol)-based service-based interface (SBI). The above-mentioned "control signal" may also be a policy control request message (e.g., Npcf_SMPolicyControl_Request).

[0026] <5G core operation example> Figure 4 is a sequence diagram illustrating the processing operation of a 5G core network device in the second embodiment.

[0027] As shown in Fig. 4, the terminal is located in a 5G area and connected to an NG-RAN (Radio Access Network) (step S101). Then, the terminal is authenticated by an AUSF (Authentication Server Function) (step S102). For this authentication, subscriber contract information and authentication information held in a UDM (Unified Data Management) are used. Then, the AMF 21 performs location registration of the terminal (step S103).

[0028] The AMF 21 transmits an Nsmf_PDUSession_CreateSMContext Request message to the SMF 22 (step S104). For example, the Nsmf_PDUSession_CreateSMContext Request message corresponds to a connection instruction for the above-mentioned terminal (not shown) that the SMF 22 receives.

[0029] SMF22 sends the Nudm_SubscriberDataManagement_GET message to the UDM (step S105), and the UDM sends an Ack to SMF22 (step S106). Thereby, SMF22 can obtain subscriber information and the like about the terminal.

[0030] SMF22 sends an Access Request to Radius (step S107), and Radius sends an Ack to SMF22 (step S108).

[0031] SMF22 sends the Npcf_SMPolicyControl_Request message to PCF23 (step S109). For example, the Npcf_SMPolicyControl_Request message corresponds to the above control signal that SMF22 sends to PCF23 (that is, the policy management function unit 51).

[0032] PCF23 sends a policy notification to Gi-LAN30 (step S110). Gi-LAN30 sends an Ack to PCF23 (step S111). PCF23 sends an Ack to SMF22 (step S 112 )

[0033] SMF22 sends an Accounting Request to Radius (step S113), and Radius sends an Ack to SMF22 (step S114).

[0034] SMF22 sends an Ack to AMF21 (step S115). AMF21 sends an Ack to the terminal via NG-RAN (steps S116, S117).

[0035] <Third Embodiment> The third embodiment relates to a more specific embodiment. The third embodiment will particularly describe the case where the core network is EPC.

[0036] <Overview of EPC> Fig. 5 is a schematic diagram of the EPC. In Fig. 5, the EPC 60 includes a Mobility Management Entity (MME) 61, a Serving Gateway (S-GW) 62, a Packet Data Network Gateway (P-GW) 63, and a Policy and Charging Rules Function (PCRF) 64.

[0037] The MME 61 is a functional unit that performs mobility management and session management.

[0038] The S-GW 62 is a functional unit that connects the U-plane between the E-UTRAN and the EPC 60 and routes and transfers user packets.

[0039] The P-GW 63 is a functional unit that functions as a connection point with an external IP network and transfers user packets between the external IP network and the P-GW 63 .

[0040] The PCRF 64 is a functional unit that manages policies and charges.

[0041] <Network device configuration example> 6 is a block diagram showing an example of a network device of an EPC in the third embodiment. In Fig. 6, a network device 70 has a policy management function unit 71. The policy management function unit 71 corresponds to the PCRF 64 in Fig. 5.

[0042] Similar to the policy management functional unit 11 of the first embodiment, when the policy management functional unit 71 receives a control signal transmitted from a session management functional unit (corresponding to the above MME 61) that has received a connection instruction (e.g., Attach, etc.) from a terminal (not shown), it notifies the policy regarding the terminal (not shown) to the Gi-LAN 30. Specifically, the policy management functional unit 71 notifies this policy to the Gi-LAN 30 via an SCTP-based Diameter interface. For example, a Re-Auth-Request (RAR) may be used for this notification. Also, the above "control signal" may be a credit control message (e.g., Credit Control (CC) Request).

[0043] <Example of EPC operation> FIG. 7 is a sequence diagram for explaining the processing operations of the EPC network devices in the third embodiment.

[0044] As shown in FIG. 7, the terminal is located in a 4G area and is connected to the E-UTRAN (step S151). Then, the terminal is authenticated using the subscriber contract information and authentication information held in the HSS (Home Subscriber Server) (step S152). And the MME 61 performs location registration of the terminal (step S153).

[0045] The MME 61 transmits a Create Session Request message to the S-GW 62 (step S154). And the S-GW 62 transmits the Create Session Request message to the P-GW 63 (step S155). For example, the Create Session Request message corresponds to the connection instruction of the above terminal (not shown) received by the PCRF 64.

[0046] The P-GW 63 transmits an Access Request to the Radius (step S156), and the Radius transmits an Ack to the P-GW 63 (step S157).

[0047] The P-GW 63 transmits a Credit Control (CC) Request message to the PCRF 64 (step S158). For example, the Credit Control (CC) Request message corresponds to the above-mentioned control signal received by the PCRF 64.

[0048] The PCRF 64 transmits a Re-Auth-Request (policy notification) to the Gi-LAN 30 (step S159). The Gi-LAN 30 transmits an Ack to the PCRF 64 (step S160). The PCRF 64 transmits an Ack to the P-GW 63 (step S161).

[0049] The P-GW 63 sends an Accounting Request to the PCRF 64 (step S162), and the PCRF 64 sends an Ack to the P-GW 63 (step S163).

[0050] P-GW 63 transmits the Ack to S-GW 62 (step S164). S-GW 62 transmits the Ack to MME 61 (step S165). MME 61 transmits the Ack to the terminal via E-UTRAN (steps S166, S167).

[0051] <Other embodiments> <1> In the second embodiment, the 5G core alone is described, and in the third embodiment, the EPC alone is described, but the present disclosure is not limited to this, and it is natural that the 5G core and the EPC may coexist and be interconnected. In this case, a combination of the SMF and the P-GW (SMF-P-GW) may be one component of the 5G core. In this case, when the terminal exists in the 5G area, the AMF transmits a connection instruction to the SMF-P-GW, the SMF-P-GW transmits a control signal to the PCF, and the PCF notifies the Gi-LAN of the policy. On the other hand, when the terminal exists in the 4G area, the MME transmits a connection instruction to the SMF-P-GW, the SMF-P-GW transmits a control signal to the PCRF, and the PCRF notifies the Gi-LAN of the policy.

[0052] <2> Fig. 8 is a diagram showing an example of a hardware configuration of a network device. In Fig. 8, the network device 100 has a processor 101 and a memory 102. The processor 101 may be, for example, a microprocessor, a micro processing unit (MPU), or a central processing unit (CPU). The processor 101 may include a plurality of processors. The memory 102 is configured by a combination of a volatile memory and a non-volatile memory. The memory 102 may include a storage located away from the processor 101. In this case, the processor 101 may access the memory 102 via an I / O interface not shown.

[0053] The network devices 10, 50, 70 of the first to third embodiments may have the hardware configuration shown in FIG. 8. The policy management function units 11, 51, 71 of the network devices 10, 50, 70 of the first to third embodiments may be realized by the processor 101 reading and executing a program stored in the memory 102. The program can be stored using various types of non-transitory computer readable medium and supplied to the network devices 10, 50, 70. Examples of the non-transitory computer readable medium include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives) and magneto-optical recording media (e.g., magneto-optical disks). Further, examples of the non-transitory computer readable medium include CD-ROM (Read Only Memory), CD-R, and CD-R / W. Further, examples of the non-transitory computer readable medium include semiconductor memory. The semiconductor memory includes, for example, a mask ROM, a programmable ROM (PROM), an erasable PROM (EPROM), a flash ROM, and a random access memory (RAM). The program may also be provided to the network device 10, 50, 70 by various types of transitory computer readable medium. Examples of the transitory computer readable medium include an electric signal, an optical signal, and an electromagnetic wave. The transitory computer readable medium can provide the program to the network device 10, 50, 70 via a wired communication path such as an electric wire and an optical fiber, or via a wireless communication path.

[0054] Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. [Explanation of symbols]

[0055] 10 Network Equipment 11 Policy Management Functions 20 5G Cores 21 AMF 22 SMF 23 PCF 30 Gigabit LAN 40 Internet 50 Network Equipment 51 Policy Management Function Unit 60 EPC 61 MME 62 S-GW 63 P-GW 64 PCRF 70 Network Equipment 71 Policy Management Functions

Claims

1. A network device included in a core network, A policy management function unit that manages a policy of the terminal is provided, When the policy management function unit receives a control signal transmitted from a session management function unit that has received a connection instruction for the terminal via a TCP (Transmission Control Protocol)-based interface or an SCTP (Stream Control Transmission Protocol)-based interface, the policy management function unit notifies a LAN (Local Area Network) located between the core network and the Internet of the policy via the TCP-based interface or the SCTP-based interface. Network device.

2. The session management function unit is included in the core network. The network device according to claim 1 .

3. The core network is a 5G core network, the policy management function unit notifies the LAN of the policy via a TCP-based service-based interface; 3. A network device according to claim 1 or 2.

4. The policy management function unit is a PCF (Policy Control Function). The network device according to any one of claims 1 to 3.

5. The session management function unit is a Session Management Function (SMF). The network device according to any one of claims 1 to 4.

6. the control signal is a policy control request message; A network device according to any one of claims 1 to 5.

7. The core network is an Evolved Packet Core (EPC), The policy management function unit notifies the LAN of the policy via an SCTP-based Diameter interface.

3. A network device according to claim 1 or 2.

8. The policy management function unit is a PCRF (Policy and Charging Rules Function).

8. The network device according to claim 1, 2 or 7.

9. The session management function unit is a Mobility Management Entity (MME).

9. The network device according to claim 1, 2, 7 or 8.

10. The control signal is a credit control message.

10. The network device according to claim 1, 2, 7, 8 or 9.

11. The core network is a 5G core network and an EPC (Evolved Packet Core) interconnected.

3. A network device according to claim 1 or 2.

12. The core network includes a combination of a Session Management Function (SMF) and a Packet Data Network Gateway (P-GW), The network device according to claim 11.

13. A method performed by a network device included in a core network, comprising: the network device includes a policy management function unit that manages a policy of a terminal; The method includes notifying a LAN (Local Area Network) located between the core network and the Internet of the policy via a TCP (Transmission Control Protocol)-based interface or a SCTP (Stream Control Transmission Protocol)-based interface when the policy management function unit receives a control signal transmitted from a session management function unit that has received a connection instruction for the terminal via a TCP (Transmission Control Protocol)-based interface or a SCTP (Stream Control Transmission Protocol)-based interface. method.

14. The session management function unit is included in the core network. The method of claim 13.

15. A program for causing a network device included in a core network to execute a process, the network device includes a policy management function unit that manages a policy of a terminal; The process includes notifying a LAN (Local Area Network) located between the core network and the Internet of the policy via a TCP (Transmission Control Protocol)-based interface or a SCTP (Stream Control Transmission Protocol)-based interface when the policy management function unit receives a control signal transmitted from a session management function unit that has received a connection instruction for the terminal via a TCP (Transmission Control Protocol)-based interface or a SCTP (Stream Control Transmission Protocol)-based interface. program.

16. The session management function unit is included in the core network. The program according to claim 15.

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