Communication system, gateway, controller, and program

Abstract

To provide a system, a device, and a program for reducing the complexity of settings in managing a network slice including an IP network.SOLUTION: In a communication system 110, an SRNW 20 comprises: a controller 300; and an SR gateway 400 that converts a packet conforming to GTP-U into a packet conforming to SRv6. When the SR gateway 400 receives, from VRF connected with an IP network, its routing information and an SID of the VRF, it advertises an SR policy and an SID of a conversion unit 410 to the controller. The controller matches the VRF and the SR gateway with each other based on advertisement information from the VRF or preset VRF information and advertisement information, refers to a PFCP session, specifies a UPF and a gNB corresponding to the IP network, and advertises routing information on the UPF and an SID of the SR gateway to a VRF corresponding to the specified gNB.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a communication system, a gateway, a controller, and a program. [Background technology]

[0002] Patent Document 1 describes slicing in a mobile network that complies with 5G (5th Generation). [Prior art document] [Patent documents] [Patent Document 1] JP 2019-176384 A Summary of the Invention

[0003] According to one embodiment of the present invention, there is provided a communication system. The communication system may include a controller. The communication system may include an SR gateway that converts GTP-U-compliant packets received from a mobile network into SRv6-compliant packets. The SR gateway may include a VRF generation unit that generates multiple gNBVRFs, which are VRFs corresponding to multiple gNBs, and multiple DNVRFs, which are VRFs corresponding to multiple DNs. The SR gateway may include a message advertisement unit that advertises a message including information on the multiple gNBVRFs and multiple DNVRFs generated by the VRF generation unit to the controller. The controller may include a correspondence information generation unit that generates correspondence information that associates the multiple gNBVRFs with the multiple DNVRFs based on the message. The controller may include an information acquisition unit that acquires PFCP session information notified when the UE is attached. The controller may include a route information generation unit that generates route information for a destination address of a UPF corresponding to the UE, including an SID of a DNVRF corresponding to the UE, based on the PFCP session information and the correspondence information. The controller may include a route information advertisement unit that advertises the route information to the SR gateway.

[0004] The message advertising unit may advertise to the controller the message in which, for each of all combinations of the plurality of gNBVRFs and the plurality of DNVRFs, an N3RAN prefix corresponding to the gNBVRF and an N6DN SID corresponding to the DNVRF are stored in NLRI and an N3RAN community corresponding to the gNBVRF and an N6DN community corresponding to the DNVRF are stored in a community attribute. The message advertising unit may advertise to the controller the message in which, for a combination of a first gNBVRF among the plurality of gNBVRFs and a first DNVRF among the plurality of DNVRFs, an N3RAN prefix corresponding to the first gNBVRF and an N6DN SID corresponding to the first DNVRF are stored in NLRI in an MP_REACH_NLRI attribute and an N3RAN community corresponding to the first gNBVRF and an N6DN community corresponding to the first DNVRF are stored in a community attribute. The N6DN SID corresponding to the first DN VRF may be a common Anycast SID indicating the first DN VRF that exists in each of multiple SR gateways.

[0005] The message advertising unit may advertise to the controller a message for the plurality of gNBVRFs, in which the NLRI type is Access, the N3RAN prefix corresponding to the gBNVRF is stored in the NLRI in the MP_REACH_NLRI attribute, and the N3RAN community corresponding to the gBNVRF is stored in the community attribute, and may advertise to the controller a message for the plurality of DNVRFs, in which the NLRI type is Core, the node ID indicating the SR gateway is stored in the NLRI in the MP_REACH_NLRI attribute, the N6DN community corresponding to the DNVRF is stored in the community attribute, and the N6DN SID corresponding to the DNVRF is attached. The message advertising unit may advertise to the controller a message in which, for a first gNBVRF among the plurality of gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the first gNBVRF is stored in the NLRI in an MP_REACH_NLRI attribute, and the N3RAN community corresponding to the first gNBVRF is stored in a community attribute, and for a first DNVRF among the plurality of DNVRFs, the NLRI type is set to Core, a node ID indicating the SR gateway is stored in the NLRI in an MP_REACH_NLRI attribute, the N6DN community corresponding to the first DNVRF is stored in the community attribute, and the N6DN SID corresponding to the first DNVRF is assigned.

[0006] The controller may have a memory unit that stores DN community linking information that links a DN name that can identify an N6DN indicating a VRF corresponding to a DN with a community attribute of the N6DN, and DN-related information that can register an N3RAN prefix, an N6DN SID, and an N3RAN community corresponding to each of a plurality of DN names, and the correspondence information generation unit may, when an N6DN community included in the message advertised by the message advertising unit matches any of the community attributes of the DN community linking information, identify a DN name that corresponds to the matched community attribute, and generate the correspondence information by registering the N3RAN prefix, N6DN SID, and N3RAN community included in the message in the DN-related information corresponding to the identified DN name. The PFCP session information may include the address of the UE, the address of the gNB accommodating the UE, the address of the UPF corresponding to the UE, and the DN name of the DN with which the UE communicates, and the route information generation unit may identify the correspondence information corresponding to the DN name included in the PFCP session information, search the identified correspondence information using the address of the gNB included in the PFCP session information as a key, thereby identifying the N3RAN prefix corresponding to the address of the gNB in ​​the correspondence information, and generate the route information using the N6DN SID and N3RAN community corresponding to the identified N3RAN prefix.

[0007] According to one embodiment of the present invention, there is provided a gateway. The gateway may include a conversion unit that converts GTP-U-compliant packets received from a mobile network into SRv6-compliant packets. The gateway may include a VRF generation unit that generates multiple gNBVRFs, which are VRFs corresponding to multiple gNBs, and multiple DNVRFs, which are VRFs corresponding to multiple DNs. The gateway may include a message advertisement unit that advertises, to a controller, a message including information on the multiple gNBVRFs and multiple DNVRFs generated by the VRF generation unit.

[0008] According to one embodiment of the present invention, there is provided a program for causing a computer to function as the gateway.

[0009] According to one embodiment of the present invention, there is provided a controller. The controller may include a message receiving unit that receives a message including information on multiple gNBVRFs, which are VRFs corresponding to multiple gNBs, and multiple DNVRFs, which are VRFs corresponding to multiple DNs, based on the message. The controller may include a correspondence information generating unit that generates correspondence information that associates the multiple gNBVRFs with the multiple DNVRFs based on the message. The controller may include an information acquiring unit that acquires PFCP session information notified when the UE is attached. The controller may include a route information generating unit that generates route information for a destination address of a UPF corresponding to the UE, including an SID of a DNVRF corresponding to the UE, based on the PFCP session information and the correspondence information. The controller may include a route information advertising unit that advertises the route information to a gateway.

[0010] According to one embodiment of the present invention, there is provided a program for causing a computer to function as the controller.

[0011] According to one embodiment of the present invention, a communication system is provided. The communication system may include a controller and an SR gateway that converts GTP-U-compliant packets received from a mobile network into SRv6-compliant packets. The SR gateway may include an advertisement unit that, when receiving IP network route information and a VRF SID from a VRF connected to the IP network, advertises an SR policy including VRF information in an ED of the NLRI and an SR gateway SID to the controller. The controller may include a matching unit that matches a VRF with an SR gateway based on information advertised from the VRF or information about a pre-configured VRF and information advertised by the advertisement unit. The controller may include an identification unit that identifies a UPF and a gNB corresponding to the IP network to which the VRF is connected, by referring to a PFCP session notified when the UE is attached. The controller may include an advertisement unit that advertises the UPF route information and the SR gateway SID to the VRF corresponding to the gNB identified by the identification unit. The SR gateway may include a packet forwarding unit that imports the SID of the VRF corresponding to the UPF as a route for the UPF and forwards packets of a predetermined type to the UPF.

[0012] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0013] [Figure 1] 1 shows a schematic diagram of an example of the configuration of a communication system 10. [Figure 2] 2 is an explanatory diagram for explaining an example of processing in the communication system 10. FIG. [Figure 3] 10A and 10B show an example of the functional configuration of the N4BGPC 300 and the logical configuration of the conversion unit 410. [Figure 4] 2 is an explanatory diagram for explaining an example of processing in the communication system 10. FIG. [Figure 5]10A and 10B show an example of the functional configuration of the N4BGPC 300 and the logical configuration of the conversion unit 410. [Figure 6] 10 shows an example of the hardware configuration of a computer 1200 that functions as an N4BGPC 300 or an SRGW 400. DETAILED DESCRIPTION OF THE INVENTION

[0014] Although techniques for identifying network slices in mobile networks are known, they are limited to the mobile network. It would be desirable to be able to manage network slices that also include IP networks, but the configuration of route information, etc., can be very complicated. The communication system 10 according to this embodiment provides a technique that reduces the complexity of the configuration.

[0015] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0016] 1 schematically illustrates an example of the configuration of a communication system 10. The communication system 10 includes an N4 Border Gateway Protocol Controller (N4BGPC) 300. The N4BGPC 300 may be an example of a controller. The N4BGPC 300 may be disposed in a Segment Routing Network (SRNW) 20. The communication system 10 includes a Segment Routing Gateway (SRGW) 400. The SRGW 400 may be disposed in the SRNW 20.

[0017] The SRGW 400 may have a function of converting packets conforming to SRv6 received from an IP network into packets conforming to GTP-U. The SRGW 400 may have a function of converting packets conforming to GTP-U received from a mobile network into packets conforming to SRv6.

[0018] The N4BGPC 300 controls the SRGW 400. The N4BGPC 300 may execute processing related to the path control of the SRGW 400.

[0019] In the example shown in Figure 1, SRNW 20 is configured with VRFs (Virtual Routing and Forwarding) 202, VRF 204, VRF 206, VRF 208, VRF 210, and VRF 220. Note that the routers that realize each VRF are not shown. SRGW 400 may include VRF 210. SRGW 400 may include VRF 220. SRGW 400 may include both VRF 210 and VRF 220.

[0020] VRF 202 is connected to a Session Management Function (SMF) 110. VRF 204, VRF 206, and VRF 208 are connected to a User Plane Function (UPF) 120. VRF 210 is connected to a gNodeB (gNB) 130. In the example shown in FIG. 1, each of the multiple VRFs 210 is connected to a multiple of gNBs 130. VRF 220 is connected to a Data Network (DN) 30. In the example shown in FIG. 1, each of the multiple VRFs 220 is connected to a multiple of DNs 30.

[0021] The N4BGPC 300 acquires information about the mobile network from the SMF 110. The N4BGPC 300 acquires, for example, Packet Forwarding Control Protocol (PFCP) session information of the UE 40 from the SMF 110.

[0022] The PFCP session information includes, for example, the address of the UE 40. The PFCP session information includes, for example, the address of the gNB 130 accommodating the UE 40. The PFCP session information includes, for example, the address of the UPF 120 corresponding to the UE 40. The PFCP session information includes, for example, a network instance corresponding to the UE 40. The network instance is, for example, an access network instance, information corresponding to slice identification information capable of identifying a slice corresponding to the UE 40 in a mobile network. The slice identification information is, for example, Single-Network Slice Selection Assistance Information (S-NSSAI). The PFCP session information may include the access network instance. The PFCP session information may include a core network instance. The core network instance is, for example, information corresponding to DN identification information capable of identifying a DN.

[0023] The SRGW 400 includes a conversion unit 410 and a conversion unit 450. The conversion unit 410 has a function of converting packets conforming to GTP-U into packets conforming to SRv6. The conversion unit 410 may have a GTP4.D function. The conversion unit 410 may have a GTP6.D function.

[0024] The conversion unit 450 has a function of converting packets conforming to SRv6 into packets conforming to GTP-U. The conversion unit 450 may have a function of GTP4.E. The conversion unit 450 may have a function of GTP6.E.

[0025] In this embodiment, the N4BGPC 300 performs route setting for relaying communication between a UE (User Equipment) 40 connected to the gNB 130 and a communication partner connected to the DN 30. The communication partner may be, for example, any communication device such as any server on the Internet.

[0026] Fig. 2 is an explanatory diagram illustrating an example of processing in the communication system 10. In the example shown in Fig. 2, the conversion unit 410 of the SRGW 400 acquires a packet transmitted by the UE 40, which would conventionally be forwarded to the UPF 120, and forwards it to the DN 30 via the VRF 220. The N4BGPC 300 executes settings for this purpose.

[0027] For example, first, the VRF 220 connected to the DN 30 advertises the route information of the DN 30, a community attribute indicating the DN, and the SID 222 of the VRF 220 to each of the N4BGPC 300 and the SRGW 400. The N4BGPC 300 may set the route information of the DN 30 in advance.

[0028] When the conversion unit 410 of the SRGW 400 receives an advertisement from the VRF 220, the conversion unit 410 advertises an SR policy including information indicating the VRF 220 in the ED (End Point) of the NLRI, a community attribute indicating the DN, and the SID 411 of the conversion unit 410 to the N4BGPC 300. The information indicating the VRF 220 may be, for example, the SID 222 of the VRF 220.

[0029] N4BGPC300 matches VRF220 with SRGW400 based on information about DN30 advertised from VRF220 or set in advance and information advertised from the conversion unit 410. N4BGPC300 refers to the PFCP session 510 notified from SMF110 when UE40 is attached, and identifies the UPF120 and gNB130 corresponding to the DN30 to which VRF220 is connected. N4BGPC300 advertises the route information of UPF120, a community attribute indicating the UPF, and the SID411 of the conversion unit 410 to the VRF210 corresponding to the identified gNB130.

[0030] If multiple SRGWs 400 exist, each of these SRGWs 400 may advertise an SR policy including an individual SID 411 value to the N4BGPC 300. The SRGW 400 may receive an SR policy including an SID 411 value advertised by another SRGW 400. The N4BGPC and all SRGWs 400 may adopt the SID 411 advertised by any one of the SRGWs 400 using a common algorithm.

[0031] With the above configuration, when the gNB 130 forwards a packet received from the UE 40 to the VRF 210, the VRF 210 can forward the packet to the SRGW 400. The conversion unit 410 of the SRGW 400 converts the packet into a packet that complies with SRv6 and forwards it to the VRF 220. The packet is forwarded from the VRF 220 to the communication partner of the DN 30.

[0032] The conversion unit 410 of the SRGW 400 may forward special packets to the UPF 120 instead of the DN 30. For example, the conversion unit 410 of the SRGW 400 imports the SID of the VRF 206 corresponding to the UPF 120 as the route of the UPF 120, and forwards packets of a predetermined type to the UPF 120. An example of a packet of a predetermined type is a GTP-U message.

[0033] 3 schematically illustrates an example of the functional configuration of the N4BGPC 300 and the logical configuration of the conversion unit 410. The N4BGPC 300 includes an acquisition unit 302, a matching unit 304, an identification unit 306, and an advertising unit 308. The N4BGPC 300 may include some, but not all, of these components, or may include other components. The conversion unit 410 includes a packet conversion unit 412, an acquisition unit 414, an SR policy generation unit 416, an advertising unit 418, and a packet forwarding unit 420. The conversion unit 410 may include some, but not all, of these components, or may include other components.

[0034] The acquisition unit 302 acquires various types of information. For example, the acquisition unit 302 acquires a PFCP session 510 from the SMF 110. For example, the acquisition unit 302 acquires information advertised from a VRF. For example, the acquisition unit 302 acquires information advertised from an SRGW 400. The acquisition unit 302 may acquire route information of a preset DN 30.

[0035] The matching unit 304 performs matching using the information acquired by the acquisition unit 302. For example, the matching unit 304 matches the VRF 220 with the SRGW 400 based on the information advertised by the VRF 220 and the information advertised by the conversion unit 410 of the SRGW 400. Also, for example, the matching unit 304 matches the VRF 220 with the SRGW 400 based on the route information of the DN 30 and the information advertised by the conversion unit 410 of the SRGW 400.

[0036] The identifying unit 306 executes a identifying process related to the path setting. For example, the identifying unit 306 refers to the PFCP session 510 acquired by the acquiring unit 302, and identifies the UPF 120 and the gNB 130 corresponding to the IP network to which the VRF 220 is connected.

[0037] The advertising unit 308 executes advertising processing. For example, the advertising unit 308 advertises, to the VRF 210 corresponding to the gNB 130 identified by the identification unit 306, the route information of the UPF 120 identified by the identification unit 306, a community attribute indicating the UPF, and the SID 411 of the conversion unit 410 of the SRGW 400.

[0038] The packet conversion unit 412 converts packets conforming to GTP-U into packets conforming to SRv6. The packet conversion unit 412 may convert packets conforming to GTP-U received from a mobile network into packets conforming to SRv6.

[0039] The acquisition unit 414 acquires various types of information. For example, the acquisition unit 414 acquires information advertised by a VRF.

[0040] The SR policy generation unit 416 generates an SR policy. For example, when the acquisition unit 414 receives IP network route information, a community attribute indicating the IP network, and an SID of the VRF from a VRF connected to the IP network, the SR policy generation unit 416 generates an SR policy including the SID of the VRF in the ED of the NLRI.

[0041] The advertising unit 418 executes advertising processing. For example, the advertising unit 418 advertises the SR policy generated by the SR policy generation unit 416, the community attribute indicating the IP network, and the SID of the SRGW 400 to the N4BGPC 300.

[0042] The packet forwarding unit 420 executes packet forwarding. For example, when the packet forwarding unit 420 receives a packet addressed to the DN 30 from the VRF 210, it forwards the packet to the VRF 220 using the route information received from the VRF 220.

[0043] The packet forwarding unit 420 may forward special packets to the UPF 120 instead of the DN 30. For example, the packet forwarding unit 420 imports the SID of the VRF 206 corresponding to the UPF 120 as the route of the UPF 120, and forwards packets of a predetermined type to the UPF 120. An example of the predetermined type of packet is a GTP-U message.

[0044] 4 is an explanatory diagram for describing an example of processing in the communication system 10. Here, processing related to the transfer of a packet from the UE 40 to the DN 30 in the communication system 10 will be described.

[0045] 4, the SRGW 400 acquires a packet transmitted by the UE 40, which would conventionally be forwarded to the UPF 120, and forwards it to the DN 30. The N4BGPC 300 executes settings for this purpose.

[0046] Here, the VRF name of VRF210 corresponding to gNB130 is N3RAN, and the VRF name of VRF220 corresponding to DN30 is N6DN.

[0047] For example, first, the N4BGPC300 generates a DN community linking table that links N6DN DN names with N6DN community attributes. As an example, the N4BGPC300 generates a DN community linking table in the format shown in Table 1. Then, the N4BGPC300 registers multiple combinations of DN names and community attributes in the DN community linking table. The N4BGPC300 may perform registration in accordance with instructions from an operator or the like.

[0048] [Table 1]

[0049] The DN community linking table may be an example of DN community linking information that links DN names of N6DN with community attributes of N6DN. The DN community linking information may have a table format in this way, but may also be data that does not have a table format and links DN names of N6DN with community attributes of N6DN.

[0050] In addition, the N4BGPC 300 generates a DN table in which an N3RAN prefix, an N6DN SID, and an N3RAN community corresponding to each of a plurality of DN names can be registered. As an example, the N4BGPC 300 generates a DN table in the format shown in Table 2.

[0051] [Table 2]

[0052] The DN table may be an example of DN-related information in which N3RAN prefixes, N6DN SIDs, and N3RAN communities can be registered. The DN-related information may have a table format as described above, but may not have a table format and may instead be data linking N3RAN prefixes, N6DN SIDs, and N3RAN communities.

[0053] Then, the N4BGPC 300 generates a DN table linking table that links the DN name with a pointer that indicates the DN table. As an example, the N4BGPC 300 generates a DN table linking table in the format shown in Table 3.

[0054] [Table 3]

[0055] The DN table linking table may be an example of DN-related information linking information in which DN names are linked with pointers indicating DN-related information. The DN-related information linking information may have a table format in this way, but may also be data that does not have a table format and links DN names with pointers indicating DN tables.

[0056] The SRGW 400 generates a plurality of VRFs 210 corresponding to the plurality of gNBs 130. The SRGW 400 generates a plurality of VRFs 220 corresponding to the plurality of DNs 30. The SRGW 400 then advertises information about the plurality of VRFs 210 and the plurality of VRFs 220 to the N4BGPC 300.

[0057] The SRGW 400 may include information on a plurality of VRFs 210 and a plurality of VRFs 220 in a BGP message and transmit the message to the N4BGPC 300. The SRGW 400 may include information on a plurality of VRFs 210 and a plurality of VRFs 220 in a BGP update message and transmit the message to the N4BGPC 300. Such a message may be referred to as a GW Discovery Route.

[0058] The SRGW 400 may configure all combinations of VRF 210 and VRF 220 and advertise information on all combinations to the N4BGPC 300. Alternatively, the SRGW 400 may advertise information on all VRF 210 and VRF 220 to the N4BGPC 300, and the N4BGPC 300 may configure all combinations of VRF 210 and VRF 220. The former may be referred to as the first method, and the latter may be referred to as the second method.

[0059] In the first method, the SRGW 400 may store an N3RAN prefix and an N6DN SID in the NLRI for each of all combinations of VRF 210 and VRF 220, generate a GW Discovery Route in which an N6DN community and an N3RAN community are stored in the community attribute, and advertise the GW Discovery Route to the N4BGPC 300. The GW Discovery Route may be a BGP-LS (Link State) Route.

[0060] Here, an example will be described in which the SRGW 400 includes a first VRF 210, a second VRF 210, a third VRF 210, a first VRF 220, a second VRF 220, and a third VRF 220.

[0061] For a combination of the first VRF 210 and the first VRF 220, the SRGW 400 stores an N3RAN prefix corresponding to the first VRF 210 and an N6DN SID corresponding to the first VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the first VRF 210 and the N6DN community corresponding to the first VRF 220 are stored in the community attribute. The N6DN SID corresponding to the first VRF 220 may be stored in a BGP-LS attribute. The N3RAN prefix corresponding to the first VRF 210 may be the address of one or more gNBs 130 connected to the first VRF 210. The N6DN SID corresponding to the first VRF 220 may be an SID indicating the first VRF 220 in the SRGW 400. The SID indicating the first VRF 220 may be a common Anycast SID indicating the first VRF 220 present in each of the multiple SRGWs 400. Alternatively, it may be the SID of the VRF 250 of one or more PE (Provider Edge) routers 50 connected to the first VRF 220.

[0062] For a combination of the first VRF 210 and the second VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the first VRF 210 and the N6DN SID corresponding to the second VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the first VRF 210 and the N6DN community corresponding to the second VRF 220 are stored in the community attribute. The N6DN SID corresponding to the second VRF 220 may be stored in the BGP-LS attribute. Furthermore, for a combination of the first VRF 210 and the third VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the first VRF 210 and the N6DN SID corresponding to the third VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the first VRF 210 and the N6DN community corresponding to the third VRF 220 are stored in the community attribute. The N6DN SID corresponding to the third VRF 220 may be stored in the BGP-LS attribute.

[0063] For a combination of the second VRF 210 and the first VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the second VRF 210 and the N6DN SID corresponding to the first VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the second VRF 210 and the N6DN community corresponding to the first VRF 220 are stored in the community attribute. The N6DN SID corresponding to the first VRF 220 may be stored in the BGP-LS attribute. Furthermore, for the combination of the second VRF 210 and the second VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the second VRF 210 and the N6DN SID corresponding to the second VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the second VRF 210 and the N6DN community corresponding to the second VRF 220 are stored in the community attribute. The N6DN SID corresponding to the second VRF 220 may be stored in the BGP-LS attribute. Furthermore, for a combination of the second VRF 210 and the third VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the second VRF 210 and the N6DN SID corresponding to the third VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the second VRF 210 and the N6DN community corresponding to the third VRF 220 are stored in the community attribute. The N6DN SID corresponding to the third VRF 220 may be stored in the BGP-LS attribute.

[0064] For the combination of the third VRF 210 and the first VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the third VRF 210 and the N6DN SID corresponding to the first VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the third VRF 210 and the N6DN community corresponding to the first VRF 220 are stored in the community attribute. The N6DN SID corresponding to the first VRF 220 may be stored in the BGP-LS attribute. Furthermore, for a combination of the third VRF 210 and the second VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the third VRF 210 and the N6DN SID corresponding to the second VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the third VRF 210 and the N6DN community corresponding to the second VRF 220 are stored in the community attribute. The N6DN SID corresponding to the second VRF 220 may be stored in the BGP-LS attribute. Furthermore, for the combination of the third VRF 210 and the third VRF 220, the SRGW 400 stores the N3RAN prefix corresponding to the third VRF 210 and the N6DN SID corresponding to the third VRF 220 in the NLRI in the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the third VRF 210 and the N6DN community corresponding to the third VRF 220 are stored in the community attribute. The N6DN SID corresponding to the third VRF 220 may be stored in the BGP-LS attribute.

[0065] In the second method, the SRGW 400 may generate a GW Discovery Route by separating the NLRI types. For example, the NLRI type that stores an N3RAN prefix is ​​set to Access, and the NLRI type that stores an N6DN SID is set to Core. The SRGW 400 may generate a GW Discovery Route for multiple VRFs 210 in which the NLRI type is set to Access, the N3RAN prefix is ​​stored in the NLRI in the MP_REACH_NLRI attribute, and the N3RAN community is stored in the community attribute. When there are multiple VRFs 210 that can access the same UPF 120, the N3RAN prefixes owned by the multiple VRFs 210 may be stored in a single BGP update message that has a common N3RAN community attribute. Furthermore, the SRGW 400 may generate a GW Discovery Route for multiple VRFs 220, with the NLRI type set to Core, a node ID indicating the SRGW 400 itself stored in the NLRI in the MP_REACH_NLRI attribute, an N6DN community stored in the community attribute, and an N6DN SID assigned. Then, the SRGW 400 advertises the generated GW Discovery Route to the N4BGPC 300. The GW Discovery Route may be a BGP-LS Route.

[0066] Here, an example will be described in which the SRGW 400 includes a first VRF 210, a second VRF 210, a third VRF 210, a first VRF 220, a second VRF 220, and a third VRF 220.

[0067] The SRGW 400 may generate a GW Discovery Route in which the NLRI type is set to Access, an N3RAN prefix corresponding to the first VRF 210 is stored in the NLRI in the MP_REACH_NLRI attribute, and an N3RAN community corresponding to the first VRF 210 is stored in the community attribute. The SRGW 400 may also generate a GW Discovery Route in which the NLRI type is set to Access, an N3RAN prefix corresponding to the second VRF 210 is stored in the NLRI in the MP_REACH_NLRI attribute, and an N3RAN community corresponding to the second VRF 210 is stored in the community attribute. The SRGW 400 may also generate a GW Discovery Route in which the NLRI type is set to Access, an N3RAN prefix corresponding to the third VRF 210 is stored in the NLRI in the MP_REACH_NLRI attribute, and an N3RAN community corresponding to the third VRF 210 is stored in the community attribute.

[0068] Furthermore, SRGW 400 may generate a GW Discovery Route with the NLRI type set to Core, with a node ID indicating SRGW 400 itself stored in the NLRI in the MP_REACH_NLRI attribute, with an N6DN community corresponding to the first VRF 220 stored in the community attribute, and with an N6DN SID corresponding to the first VRF 220. Furthermore, SRGW 400 may generate a GW Discovery Route with the NLRI type set to Core, with a node ID indicating SRGW 400 itself stored in the NLRI in the MP_REACH_NLRI attribute, with an N6DN community corresponding to the second VRF 220 stored in the community attribute, and with an N6DN SID corresponding to the second VRF 220. In addition, SRGW400 may generate a GW Discovery Route with the NLRI type set to Core, with a node ID indicating SRGW400 itself stored in the NLRI in the MP_REACH_NLRI attribute, with the N6DN community corresponding to the third VRF220 stored in the community attribute, and with an N6DN SID corresponding to the third VRF220 assigned.

[0069] In the first method, the N4BGPC 300 can grasp, by the received GW Discovery Route, the combinations of the VRF 210 and the VRF 220. In the second method, the N4BGPC 300 may configure all combinations of the VRF 210 and the VRF 220.

[0070] If the community of the N6DN of the GW Discovery Route acquired from the SRGW 400 matches any of the community attributes in the DN community linking table, the N4BGPC 300 identifies the DN name corresponding to the matched community attribute. Then, the N4BGPC 300 refers to the DN table linking table to identify the DN table pointer corresponding to the identified DN name.

[0071] The N4BGPC 300 registers the N3RAN prefix, N6DN SID, and N3RAN community included in the GW Discovery Route in the DN table pointed to by the identified DN table pointer. The N4BGPC 300 registers information on multiple GW Discovery Routes received from the SRGW 400 in DN tables corresponding to each of multiple DN names. This completes the preparation of the database. The DN table may have a Patricia tree structure with the N3RAN prefix as a key.

[0072] The N4BGPC 300 acquires the PFCP session information of the UE 40 from the SMF 110. The N4BGPC 300 acquires the PFCP session information notified by the SMF 110 when the UE 40 is attached.

[0073] The PFCP session information may include an address of the UE 40. The PFCP session information may include an address of the gNB 130 accommodating the UE 40. The PFCP session information may include an address of the UPF 120 corresponding to the UE 40. The PFCP session information may include a network instance corresponding to the UE 40. The PFCP session information may include an access network instance. The PFCP session information may include a core network instance. The PFCP session information may include a Core DN name.

[0074] When N4BGPC300 acquires the PFCP session information of UE40, it generates route information addressed to UPF120. N4BGPC300 searches the DN table linking table using the Core DN name included in the PFCP session information, identifies a pointer indicating the DN table corresponding to the Core DN name, and identifies the DN table indicated by the pointer. N4BGPC300 performs a search on the identified DN table using the address (N3RAN prefix) of the gNB130 included in the PFCP session information as a key, and identifies the entry for the N3RAN prefix in the DN table. The search of the DN table may identify an N3RAN prefix entry by longest prefix match.

[0075] N4BGPC300 generates route information for the destination address of UPF120 using the N6DN SID and N3RAN community in the entry, and advertises it to SRGW400. For example, N4BGPC300 stores the address of UPF120 in NLRI, stores the address of N4BGPC300 in Nexthop-Address, adds the N6DN SID in the entry, and generates a BGP update message that stores the N3RAN community in the entry as the community attribute of the route, and advertises it to SRGW400. The route information for the destination address of UPF120 advertised to SRGW400 may be route information indicating GTP4.D or GTP6.D.

[0076] The N4BGPC 300 may use a community attribute that specifies an N6DN VRF in route information for the UPF 120 destination address that is advertised to multiple SRGWs 400, each having a different N6DN SID. If the VRF 220 can be identified as an N6DN VRF in all target SRGWs 400 using this community, the N4BGPC 300 may advertise only one common UPF 120 destination address route information with the N6DN community added to all SRGWs 400, instead of advertising multiple UPF 120 destination address route information with N6DN SIDs added corresponding to each individual SRGW 400. The community attribute that specifies the N6DN may be the Color community. A community attribute directly intended to identify the N6DN may be defined and used as the community attribute that specifies the N6DN.

[0077] When N4BGPC 300 knows the N3RAN community in advance and advertises route information to UPF 120 that identifies the N6DN VRF by the community attribute to SRGW 400, it may advertise the UPF 120 route with only the community attribute that identifies the N6DN attached without searching the DN table. In this case, SRGW 400 does not need to advertise the GW Discovery Route to N4BGPC 300.

[0078] By referring to the community attribute of the received route information, the SRGW 400 recognizes that the route information is route information to be imported into the VRF 210 of the N3RAN, and imports the route information with the UPF 120 as the destination into the VRF 210. This enables the SRGW 400 to acquire packets transmitted by the UE 40 that would conventionally be forwarded to the UPF 120, and forward them to the DN 30.

[0079] 5 schematically illustrates an example of the functional configuration of the N4BGPC 300 and the logical configuration of the conversion unit 410. The N4BGPC 300 includes a storage unit 312, a generation unit 314, a registration unit 316, a message reception unit 318, a correspondence information generation unit 320, an information acquisition unit 322, a route information generation unit 324, and an advertising unit 326. The conversion unit 410 includes a VRF generation unit 422, an advertising unit 424, a route information reception unit 426, a route setting unit 428, a packet conversion unit 430, and a packet forwarding unit 432.

[0080] The generating unit 314 generates DN community linking information. The generating unit 314 generates, for example, a DN community linking table. The generating unit 314 stores the generated DN community linking information in the storage unit 312.

[0081] The registration unit 316 registers a plurality of combinations of DN names and community attributes in the DN community association information. The registration unit 316 may execute registration in accordance with instructions from an operator of the communication system 10 or the like.

[0082] The generating unit 314 generates DN-related information. The generating unit 314 generates, for example, a DN table. The generating unit 314 stores the generated DN-related information in the storage unit 312.

[0083] The generating unit 314 generates DN related information linking information. The generating unit 314 generates, for example, a DN table linking table. The generating unit 314 stores the generated DN related information linking information in the storage unit 312.

[0084] The VRF generation unit 422 generates a VRF. For example, the VRF generation unit 422 generates a plurality of gNB VRFs corresponding to the plurality of gNBs 130, respectively. The VRF 210 may be an example of a gNB VRF. For example, the VRF generation unit 422 generates a plurality of DN VRFs corresponding to the plurality of DNs 30, respectively. The VRF 220 may be an example of a DN VRF.

[0085] The advertising unit 424 advertises information about the VRF generated by the VRF generation unit 422 to the N4BGPC 300. The advertising unit 424 advertises, for example, a message including information about multiple gNBVRFs and multiple DNVRFs generated by the VRF generation unit 422 to the N4BGPC 300. The message may be a BGP message. The message may be a BGP update message. The message may be a GW Discovery Route. The GW Discovery Route may be a BGP-LS Route. The advertising unit 424 may be an example of a message advertising unit. The message receiving unit 318 receives the message advertised by the advertising unit 424.

[0086] The advertising unit 424 may configure all combinations of gNBVRFs and DNVRFs and advertise information on all combinations to the N4BGPC 300. For example, the advertising unit 424 advertises to the N4BGPC 300 a message that stores, for each of all combinations of multiple gNBVRFs and multiple DNVRFs, an N3RAN prefix corresponding to the gNBVRF and an N6DN SID corresponding to the DNVRF in the NRLI, and stores, in the community attribute, an N3RAN community corresponding to the gNBVRF and an N6DN community corresponding to the DNVRF.

[0087] As a specific example, for a combination of a first gNBVRF among multiple gNBVRFs and a first DNVRF among multiple DNVRFs, the advertising unit 424 stores an N3RAN prefix corresponding to the first gNBVRF and an N6DN SID corresponding to the first DNVRF in the NLRI in the MP_REACH_NLRI attribute, and advertises a message to the N4BGPC 300 in which the N3RAN community corresponding to the first gNBVRF and the N6DN community corresponding to the first DNVRF are stored in the community attribute. The N6DN SID corresponding to the first DNVRF may be stored in a BGP-LS attribute. The N3RAN prefix corresponding to the first gNBVRF may be the address of one or more gNBs 130 connected to the first gNBVRF. The N6DN SID corresponding to the first DNVRF may be an SID indicating the first DNVRF in the SRGW 400. The SID indicating the first DNVRF may be a common Anycast SID indicating the first DNVRF present in each of the multiple SRGWs 400. Also, the SID indicating the first DNVRF may be the SID of the VRF 250 of one or more PE routers 50 connected to the first DNVRF.

[0088] Alternatively, the advertising unit 424 may advertise information on all gNBVRFs and DNVRFs to the N4BGPC 300, and the N4BGPC 300 may configure all combinations of gNBVRFs and DNVRFs. For example, the advertising unit 424 advertises to the N4BGPC 300 a message in which, for multiple gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the gBNVRF is stored in the NLRI in the MP_REACH_NLRI attribute, and the N3RAN community corresponding to the gBNVRF is stored in the community attribute, and for multiple GNVRFs, the advertising unit 424 advertises to the N4BGPC 300 a message in which the NLRI type is set to Core, the node ID indicating the SRGW 400 is stored in the NLRI in the MP_REACH_NLRI attribute, the N6DN community corresponding to the GNVRF is stored in the community attribute, and the N6DN SID corresponding to the GNVRF is assigned.

[0089] As a specific example, the advertising unit 424 advertises to N4BGPC300 a message in which, for a first gNBVRF among the multiple gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the first gNBVRF is stored in the NLRI in the MP_REACH_NLRI attribute, and the N3RAN community corresponding to the first gNBVRF is stored in the community attribute, and for a first DNVRF among the multiple DNVRFs, the advertising unit 424 advertises to N4BGPC300 a message in which the NLRI type is set to Core, a node ID indicating SRGW400 is stored in the NLRI in the MP_REACH_NLRI attribute, the N6DN community corresponding to the first DNVRF is stored in the community attribute, and the N6DN SID corresponding to the first DNVRF is attached.

[0090] The correspondence information generation unit 320 generates correspondence information that associates multiple gNBVRFs with multiple DNVRFs based on the message received by the message receiving unit 318. When the N6DN community included in the message matches any of the community attributes in the DN community association information stored in the storage unit 312, the correspondence information generation unit 320 identifies the DN name corresponding to the matching community attribute. Then, the correspondence information generation unit 320 references the DN-related information association information stored in the storage unit 312 to identify the DN-related information indicated by the DN-related information pointer corresponding to the identified DN name. The correspondence information generation unit 320 registers the N3RAN prefix, N6DN SID, and N3RAN community included in the message in the identified DN-related information. The correspondence information generation unit 320 registers information of the multiple messages received from the advertising unit 424 in DN-related information corresponding to each of the multiple DN names. In this way, the correspondence information generation unit 320 generates correspondence information. In other words, the correspondence information may be DN-related information in which multiple pieces of information are registered.

[0091] The information acquisition unit 322 acquires the PFCP session information of the UE 40. The information acquisition unit 322 may acquire the PFCP session information of the UE 40 from the SMF 110. For example, the information acquisition unit 322 acquires the PFCP session information notified from the SMF 110 when the UE 40 is attached to a mobile network.

[0092] When the information acquisition unit 322 acquires the PFCP session information of the UE 40, the route information generation unit 324 generates route information addressed to the UPF 120. The route information generation unit 324 may generate route information for the destination address of the UPF 120 corresponding to the UE 40, which includes the SID of the DNVRF corresponding to the UE 40, based on the PFCP session information and the correspondence information generated by the correspondence information generation unit 320.

[0093] For example, the route information generation unit 324 searches the DN-related information linking information stored in the storage unit 312 using the DN name included in the PFCP session information, identifies a pointer indicating the correspondence information corresponding to the DN name, and identifies the correspondence information indicated by the pointer. The route information generation unit 324 searches the identified correspondence information using the address of the gNB included in the PFCP session information as a key to identify the N3RAN prefix corresponding to the address of the gNB in ​​the correspondence information, and generates route information using the N6DN SID and N3RAN community corresponding to the identified N3RAN prefix.

[0094] As a specific example, when the corresponding information is a DN table, the route information generation unit 324 identifies the DN table corresponding to the DN name, performs a search on the DN table using the address (N3RAN prefix) of the gNB included in the PFCP session information as a key, and identifies the entry for the N3RAN prefix in the DN table. Then, the route information generation unit 324 generates route information using the N6DN SID and N3RAN community in the identified entry.

[0095] The advertising unit 326 advertises the route information generated by the route information generation unit 324 to the SRGW 400. For example, the advertising unit 326 stores the address of the UPF 120 in the NLRI, stores the address of the N4BGPC 300 in the Nexthop-Address, adds the N6DN SID in the entry, and generates a BGP update message that stores the N3RAN community in the entry as a community attribute of the route, and advertises the message to the SRGW 400. The advertising unit 326 may be an example of a route information advertising unit.

[0096] The route information generation unit 324 may use a community attribute that specifies an N6DN VRF in route information for the destination address of the UPF 120 that is advertised to multiple SRGWs 400, each having a different N6DN SID. If the DN VRF can be specified as an N6DN VRF in all target SRGWs 400 using the community, the advertising unit 326 may advertise only one common UPF 120 destination address route information to which the N6DN community is added to all SRGWs 400, instead of advertising multiple pieces of UPF 120 destination address route information to which an N6DN SID corresponding to each individual SRGW 400 is added.

[0097] Note that when the advertising unit 326 knows the N3RAN community in advance and advertises route information for the UPF 120 that identifies the N6DN VRF based on the community attribute to the SRGW 400, the advertising unit 326 may advertise the route to the UPF 120 without searching the DN table. In this case, the SRGW 400 does not need to advertise the GW Discovery Route to the N4BGPC 300.

[0098] The route information receiving unit 426 receives the route information advertised by the advertising unit 326. The route setting unit 428 performs route setting based on the route information received by the advertising unit 326. By referencing the community attribute of the received route information, the route setting unit 428 can recognize that the route information is route information to be imported into the VRF 210 of the N3RAN. In this case, the route setting unit 428 imports route information with the UPF 120 as the destination into the VRF 210.

[0099] The packet conversion unit 430 converts packets conforming to GTP-U into packets conforming to SRv6. The packet conversion unit 430 may convert packets conforming to GTP-U received from a mobile network into packets conforming to SRv6.

[0100] The packet forwarding unit 432 forwards packets. The packet forwarding unit 432 forwards packets in accordance with the route set by the route setting unit 428. For example, the packet forwarding unit 432 controls the packet conversion unit 430 to change a packet that is sent by the UE 40, arrives at the VRF 210, and has the destination UPF 120, so that the packet is forwarded to the corresponding DN 30 via the corresponding VRF 220.

[0101] 6 schematically illustrates an example of the hardware configuration of a computer 1200 that functions as the N4BGPC 300 or the SRGW 400. A program installed on the computer 1200 can cause the computer 1200 to function as one or more “parts” of an apparatus according to the present embodiment, or can cause the computer 1200 to perform operations associated with the apparatus according to the present embodiment or one or more “parts” thereof, and / or can cause the computer 1200 to perform a process according to the present embodiment or steps of the process. Such a program can be executed by the CPU 1212 to cause the computer 1200 to perform specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0102] The computer 1200 according to this embodiment includes a CPU 1212, a RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communications interface 1222, a storage device 1224, a DVD drive, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The DVD drive may be a DVD-ROM drive, a DVD-RAM drive, or the like. The storage device 1224 may be a hard disk drive, a solid-state drive, or the like. The computer 1200 also includes a ROM 1230 and legacy input / output units such as a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0103] The CPU 1212 operates according to programs stored in the ROM 1230 and the RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires image data generated by the CPU 1212 into a frame buffer or the like provided in the RAM 1214 or into the graphics controller itself, and causes the image data to be displayed on the display device 1218.

[0104] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive reads programs or data from a DVD-ROM or the like and provides them to the storage device 1224. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0105] The ROM 1230 stores therein a boot program or the like that is executed by the computer 1200 upon activation, and / or programs that depend on the hardware of the computer 1200. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via a USB port, a parallel port, a serial port, a keyboard port, a mouse port, etc.

[0106] The programs are provided by a computer-readable storage medium such as a DVD-ROM or an IC card. The programs are read from the computer-readable storage medium, installed in the storage device 1224, RAM 1214, or ROM 1230, which are also examples of computer-readable storage media, and executed by the CPU 1212. Information processing described in these programs is read by the computer 1200, and causes cooperation between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing operations or processing of information in accordance with the use of the computer 1200.

[0107] For example, when communication is performed between the computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into the RAM 1214 and instruct the communication interface 1222 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer area provided in the RAM 1214, the storage device 1224, a DVD-ROM, or a recording medium such as an IC card, and transmits the read transmission data to the network, or writes reception data received from the network to a reception buffer area or the like provided on the recording medium.

[0108] Furthermore, the CPU 1212 may cause all or a necessary portion of a file or database stored in an external recording medium such as the storage device 1224, a DVD drive (DVD-ROM), an IC card, etc. to be read into the RAM 1214, and may perform various types of processing on the data on the RAM 1214. The CPU 1212 may then write back the processed data to the external recording medium.

[0109] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and may undergo information processing. The CPU 1212 may perform various types of processing on data read from the RAM 1214, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described throughout this disclosure and specified by the instruction sequences of the programs, and write the results back to the RAM 1214. The CPU 1212 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries, each having an attribute value of a first attribute associated with an attribute value of a second attribute, are stored on the recording medium, the CPU 1212 may search for an entry whose attribute value of the first attribute matches a specified condition from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0110] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 1200. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can also be used as a computer-readable storage medium, thereby providing the programs to the computer 1200 via the network.

[0111] The blocks in the flowcharts and block diagrams in the present embodiments may represent stages of a process in which an operation is performed or "parts" of an apparatus responsible for performing the operation. Particular stages and "parts" may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuitry may include digital and / or analog hardware circuits, including integrated circuits (ICs) and / or discrete circuits. The programmable circuitry may include reconfigurable hardware circuits, such as field programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), including AND, OR, XOR, NAND, NOR, and other logical operations, flip-flops, registers, and memory elements.

[0112] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by an appropriate device, such that a computer-readable storage medium having instructions stored thereon comprises an article of manufacture, including instructions that can be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disc (DVD), Blu-ray disc, memory stick, integrated circuit card, etc.

[0113] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0114] Computer-readable instructions may be provided locally or over a wide area network (WAN) such as a local area network (LAN), the Internet, etc. to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, or programmable circuitry, such that the processor or programmable circuitry executes the computer-readable instructions to generate means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc.

[0115] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0116] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0117] 10 communication system, 20 SRNW, 30 DN, 40 UE, 50 PE router, 110 SMF, 120 UPF, 130 gNB, 202, 204, 206, 208, 210, 220 VRF, 222 SID, 250 VRF, 300 N4BGPC, 302 acquisition unit, 304 matching unit, 306 identification unit, 308 advertising unit, 312 storage unit, 314 generation unit, 316 registration unit, 318 message reception unit, 320 correspondence information generation unit, 322 information acquisition unit, 324 route information generation unit, 326 advertising unit, 400 SRGW, 410 conversion unit, 412 packet conversion unit, 414 acquisition unit, 416 SR policy generation unit, 418 advertising unit, 420 packet forwarding unit, 422 VRF generation unit, 424 advertising unit, 426 route information receiving unit, 428 route setting unit, 430 packet conversion unit, 432 packet forwarding unit, 450 conversion unit, 510 PFCP session, 1200 computer, 1210 host controller, 1212 CPU, 1214 RAM, 1216 graphic controller, 1218 display device, 1220 input / output controller, 1222 communication interface, 1224 storage device, 1230 ROM, 1240 input / output chip

Claims

1. A controller; an SR gateway that converts packets conforming to GTP-U received from a mobile network into packets conforming to SRv6; Equipped with The SR gateway A VRF generation unit that generates a plurality of gNB VRFs, which are VRFs corresponding to each of a plurality of gNBs, and a plurality of DNVRFs, which are VRFs corresponding to each of a plurality of DNs; a message advertising unit that advertises a message including information on the plurality of gNB VRFs and the plurality of DNVRFs generated by the VRF generation unit to the controller; and The controller A correspondence information generation unit that generates correspondence information that associates multiple gNBVRFs with multiple DNVRFs based on the message; an information acquisition unit that acquires PFCP session information notified when a UE is attached; A route information generation unit that generates route information for a destination address of a UPF corresponding to the UE based on the PFCP session information and the correspondence information, the route information including a SID of a DNVRF corresponding to the UE; a route information advertisement unit that advertises the route information to the SR gateway; A communication system comprising:

2. The communication system of claim 1, wherein the message advertising unit advertises to the controller a message that stores, for each of all combinations of the plurality of gNBVRFs and the plurality of DNVRFs, an N3RAN prefix corresponding to the gNBVRF and an N6DN SID corresponding to the DNVRF in an NLRI, and an N3RAN community corresponding to the gNBVRF and an N6DN community corresponding to the DNVRF in a community attribute.

3. The communication system of claim 2, wherein the message advertising unit stores, for a combination of a first gNBVRF among the plurality of gNBVRFs and a first DNVRF among the plurality of DNVRFs, an N3RAN prefix corresponding to the first gNBVRF and an N6DN SID corresponding to the first DNVRF in an NLRI in an MP_REACH_NLRI attribute, and advertises to the controller the message in which the N3RAN community corresponding to the first gNBVRF and the N6DN community corresponding to the first DNVRF are stored in a community attribute.

4. 4. The communication system according to claim 3, wherein the N6DN SID corresponding to the first DNVRF is a common Anycast SID indicating the first DNVRF present in each of a plurality of SR gateways.

5. The message advertising unit advertises to the controller a message in which, for the multiple gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the gNBVRF is stored in the NLRI in the MP_REACH_NLRI attribute, and the community of the N3RAN corresponding to the gNBVRF is stored in the community attribute, and for the multiple DNVRFs, the NLRI type is set to Core, the node ID indicating the SR gateway is stored in the NLRI in the MP_REACH_NLRI attribute, the community of the N6DN corresponding to the DNVRF is stored in the community attribute, and the message is assigned the N6DN SID corresponding to the DNVRF. The communication system of claim 1.

6. The communication system of claim 5, wherein the message advertising unit advertises to the controller a message in which, for a first gNBVRF among the multiple gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the first gNBVRF is stored in the NLRI in an MP_REACH_NLRI attribute, and the community of the N3RAN corresponding to the first gNBVRF is stored in a community attribute, and for a first DNVRF among the multiple DNVRFs, the NLRI type is set to Core, a node ID indicating the SR gateway is stored in the NLRI in an MP_REACH_NLRI attribute, the community of the N6DN corresponding to the first DNVRF is stored in a community attribute, and the message is assigned an N6DN SID corresponding to the first DNVRF.

7. The controller a storage unit that stores DN community linking information that links a DN name capable of identifying an N6DN indicating a VRF corresponding to the DN with a community attribute of the N6DN, and DN-related information that can register an N3RAN prefix, an N6DN SID, and an N3RAN community corresponding to each of a plurality of DN names; and 7. The communication system according to claim 2, wherein when an N6DN community included in the message advertised by the message advertising unit matches any of the community attributes of the DN community linking information, the correspondence information generation unit generates the correspondence information by identifying a DN name corresponding to the matched community attribute and registering an N3RAN prefix, an N6DN SID, and an N3RAN community included in the message in the DN related information corresponding to the identified DN name.

8. The PFCP session information includes the address of the UE, the address of the gNB accommodating the UE, the address of the UPF corresponding to the UE, and the DN name of the DN with which the UE communicates; The route information generation unit identifies the correspondence information corresponding to the DN name included in the PFCP session information, and searches the identified correspondence information using the address of the gNB included in the PFCP session information as a key to identify the N3RAN prefix corresponding to the address of the gNB in ​​the correspondence information, and generates the route information using the N6DN SID and N3RAN community corresponding to the identified N3RAN prefix. The communication system described in claim 7.

9. a conversion unit that converts packets conforming to GTP-U received from a mobile network into packets conforming to SRv6; A VRF generation unit that generates a plurality of gNB VRFs, which are VRFs corresponding to each of a plurality of gNBs, and a plurality of DNVRFs, which are VRFs corresponding to each of a plurality of DNs; a message advertising unit that advertises a message including information on the plurality of gNB VRFs and the plurality of DNVRFs generated by the VRF generation unit to a controller; Equipped with The message advertisement unit stores, for each of all combinations of the plurality of gNBVRFs and the plurality of DNVRFs, an N3RAN prefix corresponding to the gNBVRF and an N6DN SID corresponding to the DNVRF in an NLRI, and advertises to the controller the message in which an N3RAN community corresponding to the gNBVRF and an N6DN community corresponding to the DNVRF are stored in a community attribute. gateway.

10. A gateway as described in claim 9, wherein the message advertising unit, for a combination of a first gNBVRF among the plurality of gNBVRFs and a first DNVRF among the plurality of DNVRFs, stores an N3RAN prefix corresponding to the first gNBVRF and an N6DN SID corresponding to the first DNVRF in an NLRI in an MP_REACH_NLRI attribute, and advertises to the controller the message in which the N3RAN community corresponding to the first gNBVRF and the N6DN community corresponding to the first DNVRF are stored in a community attribute.

11. The gateway of claim 10, wherein the N6DN SID corresponding to the first DNVRF is a common Anycast SID indicating the first DNVRF present in each of multiple SR gateways.

12. A gateway, a conversion unit that converts packets conforming to GTP-U received from a mobile network into packets conforming to SRv6; A VRF generation unit that generates a plurality of gNB VRFs, which are VRFs corresponding to each of a plurality of gNBs, and a plurality of DNVRFs, which are VRFs corresponding to each of a plurality of DNs; a message advertising unit that advertises a message including information on the plurality of gNB VRFs and the plurality of DNVRFs generated by the VRF generation unit to a controller; Equipped with The message advertisement unit advertises to the controller a message in which, for the multiple gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the gNBVRF is stored in the NLRI in the MP_REACH_NLRI attribute, and the N3RAN community corresponding to the gNBVRF is stored in the community attribute, and for the multiple DNVRFs, the NLRI type is set to Core, the node ID indicating the gateway is stored in the NLRI in the MP_REACH_NLRI attribute, the N6DN community corresponding to the DNVRF is stored in the community attribute, and the N6DN SID corresponding to the DNVRF is assigned. gateway.

13. A program for causing a computer to function as the gateway according to any one of claims 9 to 12.

14. A message receiving unit that receives a message including information on a plurality of gNB VRFs, which are VRFs corresponding to each of a plurality of gNBs, and a plurality of DNVRFs, which are VRFs corresponding to each of a plurality of DNs; A correspondence information generation unit that generates correspondence information that associates multiple gNBVRFs with multiple DNVRFs based on the message; an information acquisition unit that acquires PFCP session information notified when a UE is attached; A route information generation unit that generates route information for a destination address of a UPF corresponding to the UE based on the PFCP session information and the correspondence information, the route information including a SID of a DNVRF corresponding to the UE; a route information advertisement unit that advertises the route information to a gateway; A controller comprising:

15. A program for causing a computer to function as the controller according to claim 14.

16. A controller; an SR gateway that converts packets conforming to GTP-U received from a mobile network into packets conforming to SRv6; Equipped with The SR gateway an advertisement unit that, when receiving route information of the IP network and an SID of the VRF from a VRF connected to the IP network, advertises to the controller an SR policy including information of the VRF in an ED of an NLRI and an SID of the SR gateway; and The controller a matching unit that matches the VRF with the SR gateway based on information advertised from the VRF or information of the VRF that has been set in advance and information advertised by the advertising unit; An identification unit that identifies a UPF and a gNB corresponding to the IP network to which the VRF is connected by referring to a PFCP session notified when the UE is attached; An advertising unit that advertises the route information of the UPF and the SID of the SR gateway to the VRF corresponding to the gNB identified by the identification unit; A communication system comprising:

17. The SR gateway A packet forwarding unit that imports the SID of the VRF corresponding to the UPF as a route for the UPF and forwards packets of a predetermined type to the UPF.

17. The communication system of claim 16, comprising:

18. A controller; an SR gateway that converts packets conforming to GTP-U received from a mobile network into packets conforming to SRv6; Equipped with The SR gateway A VRF generation unit that generates a plurality of gNB VRFs, which are VRFs corresponding to each of a plurality of gNBs, and a plurality of DNVRFs, which are VRFs corresponding to each of a plurality of DNs; a message advertising unit that advertises a message including information on the plurality of gNB VRFs and the plurality of DNVRFs generated by the VRF generation unit to the controller; and The controller A correspondence information generation unit that generates correspondence information that associates multiple gNBVRFs with multiple DNVRFs based on the message; an information acquisition unit that acquires PFCP session information notified when a UE is attached; A route information generation unit that generates route information for a destination address of a UPF corresponding to the UE based on the PFCP session information and the correspondence information, the route information including a community of a DNVRF corresponding to the UE; a route information advertisement unit that advertises the route information to the SR gateway; A communication system comprising:

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