Communication systems, controllers, and programs

Abstract

The communication system includes a controller and an SR gateway that converts GTP-U compliant packets received from a mobile network into SRv6 compliant packets, the SR gateway having a VRF generation unit that generates multiple gNBVRFs, each corresponding to one of multiple gNBs, and multiple DNVRFs, each corresponding to one of multiple DNs, the controller having a correspondence information generation unit that generates correspondence information that associates the multiple gNBVRFs with the multiple DNVRFs, 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 the destination address of the UPF corresponding to the UE, including the community of the DNVRF corresponding to the UE, based on the PFCP session information and correspondence information, and a route information advertisement unit that advertises the route information to the SR gateway.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes slicing in a mobile network compliant with 5G (5th Generation). [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-176384

Summary of the Invention

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

[0004] The above message advertising unit may advertise the above message to the controller, storing in the NLRI the N3RAN prefix corresponding to the gNBVRF and the N6DN SID corresponding to the DNVRF for each of the above multiple gNBVRFs and DNVRFs, and storing in the community attribute the N3RAN community corresponding to the gNBVRF and the N6DN community corresponding to the DNVRF. The above message advertising unit may advertise to the controller the above message, storing in the NLRI in the MP_REACH_NLRI attribute the N3RAN prefix corresponding to the first gNBVRF and the N6DN SID corresponding to the first DNVRF for each of the above multiple gNBVRFs and DNVRFs The N6DN SID corresponding to the first DNVRF described above may be a common Anycast SID that indicates the first DNVRF present in each of the multiple SR gateways.

[0005] The above message advertising unit may advertise to the controller a message for the above multiple gNBVRFs with the NLRI type set to Access, storing the N3RAN prefix corresponding to the above gBNVRF in the NLRI within the MP_REACH_NLRI attribute, and storing the N3RAN community corresponding to the above gBNVRF in the community attribute. For the above multiple DNVRFs, the NLRI type set to Core, storing the node ID indicating the above SR gateway in the NLRI within the MP_REACH_NLRI attribute, storing the N6DN community corresponding to the above DNVRF in the community attribute, and adding the N6DN SID corresponding to the above DNVRF, may advertise to the controller a message for the above multiple DNVRFs. The above message advertising unit may advertise to the controller a message for the first gNBVRF among the multiple gNBVRFs, with the NLRI type set to Access, storing the N3RAN prefix corresponding to the first gNBVRF in the NLRI attribute of MP_REACH_NLRI, and storing the N3RAN community corresponding to the first gNBVRF in the community attribute. It may also advertise to the controller a message for the first DNVRF among the multiple DNVRFs, with the NLRI type set to Core, storing the node ID indicating the SR gateway in the NLRI attribute of MP_REACH_NLRI, storing the N6DN community corresponding to the first DNVRF in the community attribute, and adding the N6DN SID corresponding to the first DNVRF.

[0006] The controller may have a storage unit that stores DN community linking information which links a DN name that can identify an N6DN that indicates a VRF corresponding to a DN with the community attribute of the N6DN, and DN related information which can register an N3RAN prefix, an N6DN SID, and an N3RAN community corresponding to each of a plurality of DN names. The corresponding information generation unit may generate the corresponding information by identifying a DN name that matches the community attribute of an N6DN included in a message advertised by the message advertising unit, and registering the N3RAN prefix, an N6DN SID, and an N3RAN community included in the message in the DN related information corresponding to the identified DN name when the community of the N6DN included in the message advertised by the message advertising unit matches any of the community attributes of the DN community linking information. 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. The routing information generation unit may identify the correspondence information corresponding to the DN name included in the PFCP session information, and by searching the identified correspondence information using the gNB address included in the PFCP session information as a key, it may identify the N3RAN prefix corresponding to the gNB address in the correspondence information, and generate the routing information using the N6DN SID and N3RAN community corresponding to the identified N3RAN prefix.

[0007] According to one embodiment of the present invention, a gateway is provided. 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 a plurality of gNBVRFs, each corresponding to a plurality of gNBs, and a plurality of DNVRFs, each corresponding to a plurality of DNs. The gateway may include a message advertisement unit that advertises a message to a controller containing information on the plurality of gNBVRFs and DNVRFs generated by the VRF generation unit.

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

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

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

[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 have an advertising unit that, upon receiving IP network routing information and the SID of a VRF connected to an IP network from a VRF connected to an IP network, advertises an SR policy containing the VRF information and the SID of the SR gateway to the controller in the ED of the NLRI. The controller may have a matching unit that matches the VRF and the SR gateway based on the information advertised from the VRF or pre-configured VRF information and the information advertised by the advertising unit. The controller may have an identification unit that refers to a PFCP session notified when a UE is attached and identifies the UPF and gNB corresponding to the IP network to which the VRF is connected. The controller may have an advertising unit that advertises the UPF routing information and the SID of the SR gateway to the VRF corresponding to the gNB identified by the identification unit. The SR gateway may have 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] It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. Furthermore, subcombinations of these features may also constitute an invention. [Brief explanation of the drawing]

[0013] [Figure 1] A schematic example of the configuration of the communication system 10 is shown below. [Figure 2] This is an explanatory diagram illustrating an example of processing in the communication system 10. [Figure 3] A schematic example of the functional configuration of the N4BGPC300 and the logical configuration of the conversion unit 410 is shown. [Figure 4] This is an explanatory diagram illustrating an example of processing in the communication system 10. [Figure 5]A schematic example of the functional configuration of the N4BGPC300 and the logical configuration of the conversion unit 410 is shown. [Figure 6] A schematic example of the hardware configuration of computer 1200, which functions as N4BGPC300 or SRGW400, is shown below. [Modes for carrying out the invention]

[0014] While technologies for identifying network slices in mobile networks are known, they have been confined to the mobile network. It is desirable to be able to manage network slices including IP networks, but this can make configuring routing information and other settings extremely complex. The communication system 10 according to this embodiment provides a technology to reduce this configuration complexity.

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

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

[0017] The SRGW400 may have a function to convert SRv6-compliant packets received from an IP network into GTP-U-compliant packets. The SRGW400 may also have a function to convert GTP-U-compliant packets received from a mobile network into SRv6-compliant packets.

[0018] N4BGPC300 controls SRGW400. N4BGPC300 may execute processing related to the path control of SRGW400.

[0019] In the example shown in FIG. 1, VRFs (Virtual Routing and Forwarding) 202, 204, 206, 208, 210, and 220 are arranged in SRNW20. Note that the illustration of the routers in which each VRF is realized is omitted. SRGW400 may include VRF210. SRGW400 may include VRF220. SRGW400 may include both VRF210 and VRF220.

[0020] VRF202 is connected to SMF (Session Management Function) 110. VRFs 204, 206, and 208 are connected to UPF (User Plane Function) 120. VRF210 is connected to gNB (gNodeB) 130. In the example shown in FIG. 1, each of the plurality of VRF210s is connected to a plurality of gNB130s. VRF220 is connected to DN (Data Network) 30. In the example shown in FIG. 1, each of the plurality of VRF220s is connected to a plurality of DNs 30.

[0021] N4BGPC300 obtains information related to the mobile network from SMF110. N4BGPC300 obtains, for example, the PFCP (Packet Forwarding Control Protocol) session information of UE40 from SMF110.

[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, the network instance corresponding to the UE 40. The network instance is information corresponding to slice identification information that can identify a slice corresponding to the UE 40 in a mobile network, for example, as an access network instance. The slice identification information is, for example, S-NSSAI (Single-Network Slice Selection Assistance Information). The PFCP session information may include an access network instance. The PFCP session information may include a core network instance. The core network instance is information corresponding to DN identification information that can identify the DN, for example.

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

[0024] The conversion unit 450 has a function of converting a packet compliant with SRv6 into a packet compliant with GTP-U. The conversion unit 450 may have the function of GTP4.E. The conversion unit 450 may have the function of GTP6.E.

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

[0026] Figure 2 is an explanatory diagram illustrating an example of processing in the communication system 10. In the example shown in Figure 2, the conversion unit 410 of the SRGW400 acquires packets transmitted by the UE40 that would conventionally be forwarded to the UPF120, and forwards them to the DN30 via the VRF220. The N4BGPC300 performs the necessary configuration.

[0027] For example, first, the VRF220 connected to DN30 advertises the routing information of DN30, the community attribute indicating the DN, and the SID222 of the VRF220 to the N4BGPC300 and SRGW400, respectively. The N4BGPC300 may have the routing information of DN30 pre-configured.

[0028] When the SRGW400's conversion unit 410 receives an advertisement from VRF220, it advertises to the N4BGPC300 an SR policy containing information indicating VRF220 in the NLRI's ED (End Point), a community attribute indicating DN, and the SID411 of the conversion unit 410. The information indicating VRF220 may be, for example, the SID222 of VRF220.

[0029] The N4BGPC300 matches the VRF220 with the SRGW400 based on the DN30 information advertised by the VRF220 or pre-configured information and the information advertised by the translation unit 410. The N4BGPC300 refers to the PFCP session 510 notified by the SMF110 when the UE40 is attached and identifies the UPF120 and gNB130 corresponding to the DN30 to which the VRF220 is connected. The N4BGPC300 advertises the routing information of the UPF120, the community attribute indicating the UPF, and the SID411 of the translation unit 410 to the VRF210 corresponding to the identified gNB130.

[0030] If multiple SRGW400s exist, each SRGW400 may advertise an SR policy containing a separate SID411 value to the N4BGPC300. An SRGW400 may receive SR policies containing SID411 values ​​advertised by other SRGW400s. The N4BGPC and all SRGW400s may adopt the SID411 advertised by any one of the SRGW400s using a common algorithm.

[0031] With the above configuration, when gNB130 forwards a packet received from UE40 to VRF210, it can instruct VRF210 to forward the packet to SRGW400. The SRGW400's conversion unit 410 converts the packet into an SRv6-compliant packet and forwards it to VRF220. From VRF220, the packet is forwarded to the communication partner of DN30.

[0032] The SRGW400's translation unit 410 may also configure special packets to be forwarded to UPF120 instead of DN30. For example, the SRGW400's translation unit 410 imports the SID of VRF206 corresponding to UPF120 as a route for UPF120, and forwards predetermined types of packets to UPF120. An example of a predetermined type of packet is a GTP-U message.

[0033] Figure 3 schematically shows an example of the functional configuration of the N4BGPC300 and the logical configuration of the conversion unit 410. The N4BGPC300 comprises an acquisition unit 302, a matching unit 304, a specific unit 306, and an advertising unit 308. The N4BGPC300 may have some of these components instead of all of them, or it may have other configurations. The conversion unit 410 comprises 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 have some of these components instead of all of them, or it may have other configurations.

[0034] The acquisition unit 302 acquires various types of information. For example, the acquisition unit 302 acquires PFCP session 510 from SMF110. For example, the acquisition unit 302 acquires advertised information from VRF. For example, the acquisition unit 302 acquires advertised information from SRGW400. The acquisition unit 302 may also acquire pre-configured routing information for DN30.

[0035] The matching unit 304 performs matching using the information acquired by the acquisition unit 302. For example, the matching unit 304 matches the VRF220 and the SRGW400 based on the information advertised by the VRF220 and the information advertised by the SRGW400's conversion unit 410. Alternatively, the matching unit 304 also matches the VRF220 and the SRGW400 based on the DN30's route information and the information advertised by the SRGW400's conversion unit 410.

[0036] The identification unit 306 performs specific processing related to route configuration. For example, the identification unit 306 refers to the PFCP session 510 acquired by the acquisition unit 302 and identifies the UPF120 and gNB130 corresponding to the IP network to which the VRF220 is connected.

[0037] The advertising unit 308 performs advertising processing. For example, the advertising unit 308 advertises the route information of the UPF120 identified by the identification unit 306, the community attribute indicating the UPF, and the SID411 of the SRGW400's conversion unit 410 to the VRF210 corresponding to the gNB130 identified by the identification unit 306.

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

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

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

[0041] The advertising unit 418 performs 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 performs packet forwarding. For example, when the packet forwarding unit 420 receives a packet destined for DN30 from VRF210, it uses the routing information received from VRF220 to forward the packet to VRF220.

[0043] The packet forwarding unit 420 may also forward special packets to UPF120 instead of DN30. For example, the packet forwarding unit 420 imports the SID of VRF206 corresponding to UPF120 as a route for UPF120, and forwards predetermined types of packets to UPF120. An example of a predetermined type of packet is a GTP-U message.

[0044] Figure 4 is an explanatory diagram illustrating an example of processing in the communication system 10. Here, we will describe the processing related to packet forwarding from UE40 to DN30 in the communication system 10.

[0045] In the example shown in Figure 4, the SRGW400 receives packets transmitted by the UE40 that would conventionally be forwarded to the UPF120, and forwards them to the DN30. The N4BGPC300 performs the necessary configuration.

[0046] In this explanation, the VRF name for VRF210 corresponding to gNB130 will be N3RAN, and the VRF name for VRF220 corresponding to DN30 will be N6DN.

[0047] For example, first, the N4BGPC300 generates a DN-community linking table that associates the DN name of an N6DN with the community attribute of an N6DN. 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 the registration according to the instructions of an operator or other person.

[0048] [Table 1]

[0049] The DN community linking table may be an example of DN community linking information that links the DN name of an N6DN with the community attribute of an N6DN. The DN community linking information may take the form of a table, but it may also be data that links the DN name of an N6DN with the community attribute of an N6DN without taking the form of a table.

[0050] Furthermore, the N4BGPC300 generates a DN table that can register N3RAN prefixes, N6DN SIDs, and N3RAN communities corresponding to each of multiple DN names. As an example, the N4BGPC300 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 that can register N3RAN prefixes, N6DN SIDs, and N3RAN communities. The DN-related information may take the form of a table, but it may also be data that links N3RAN prefixes, N6DN SIDs, and N3RAN communities without taking the form of a table.

[0053] The N4BGPC300 then generates a DN table mapping table that associates DN names with pointers that indicate DN tables. As an example, the N4BGPC300 generates a DN table mapping table in the format shown in Table 3.

[0054] [Table 3]

[0055] A DN table linking table may be an example of DN-related information linking information, which links a DN name with a pointer that indicates DN-related information. While DN-related information linking information may take the form of a table, it may also be data that does not take the form of a table, but rather links a DN name with a pointer that indicates a DN table.

[0056] The SRGW400 generates multiple VRF210s, each corresponding to a multiple gNB130. The SRGW400 generates multiple VRF220s, each corresponding to a multiple DN30. The SRGW400 then advertises the information of the multiple VRF210s and multiple VRF220s to the N4BGPC300.

[0057] SRGW400 may include information on multiple VRF210s and multiple VRF220s in a BGP message and send it to N4BGPC300. SRGW400 may include information on multiple VRF210s and multiple VRF220s in a BGP update message and send it to N4BGPC300. Such messages may be referred to as GW Discovery Routes.

[0058] SRGW400 may configure all combinations of VRF210 and VRF220 and advertise information for all combinations to N4BGPC300. Alternatively, SRGW400 may advertise information for all VRF210 and VRF220 to N4BGPC300, and N4BGPC300 may configure all combinations of VRF210 and VRF220. The former may be referred to as Method 1, and the latter as Method 2.

[0059] In the first method, SRGW400 may generate a GW Discovery Route for each of the all combinations of VRF210 and VRF220, storing the N3RAN prefix and N6DN SID in the NLRI, and storing the N6DN community and N3RAN community in the community attribute, and advertise it to N4BGPC300. The GW Discovery Route may be a BGP-LS (Link State) Route.

[0060] Here, we will explain using the example where SRGW400 includes a first VRF210, a second VRF210, a third VRF210, a first VRF220, a second VRF220, and a third VRF220.

[0061] The SRGW400 generates a GW Discovery Route for a combination of a first VRF210 and a first VRF220, storing the N3RAN prefix corresponding to the first VRF210 and the N6DN SID corresponding to the first VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and storing the N3RAN community corresponding to the first VRF210 and the N6DN community corresponding to the first VRF220 in the Community attribute. The N6DN SID corresponding to the first VRF220 may also be stored in the BGP-LS attribute. The N3RAN prefix corresponding to the first VRF210 may be the addresses of one or more gNB130s connected to the first VRF210. The N6DN SID corresponding to the first VRF220 may be the SID indicating the first VRF220 in the SRGW400. The SID indicating the first VRF220 may be a common Anycast SID indicating the first VRF220 present in each of the multiple SRGW400s. Alternatively, it may be the SID of the VRF250 of one or more PE (Provider Edge) routers 50 connected to the first VRF220.

[0062] The SRGW400 generates a GW Discovery Route for a combination of the first VRF210 and the second VRF220. For this combination, it stores the N3RAN prefix corresponding to the first VRF210 and the N6DN SID corresponding to the second VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and stores the N3RAN community corresponding to the first VRF210 and the N6DN community corresponding to the second VRF220 in the Community attribute. The N6DN SID corresponding to the second VRF220 may also be stored in the BGP-LS attribute. Furthermore, for the combination of the first VRF210 and the third VRF220, the SRGW400 stores the N3RAN prefix corresponding to the first VRF210 and the N6DN SID corresponding to the third VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the community of the N3RAN corresponding to the first VRF210 and the community of the N6DN corresponding to the third VRF220 are stored in the community attribute. The N6DN SID corresponding to the third VRF220 may also be stored in the BGP-LS attribute.

[0063] For the combination of the second VRF210 and the first VRF220, the SRGW400 stores the N3RAN prefix corresponding to the second VRF210 and the N6DN SID corresponding to the first VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the community of the N3RAN corresponding to the second VRF210 and the community of the N6DN corresponding to the first VRF220 are stored in the community attribute. The N6DN SID corresponding to the first VRF220 may also be stored in the BGP-LS attribute. Furthermore, for the combination of the second VRF210 and the second VRF220, the SRGW400 stores the N3RAN prefix corresponding to the second VRF210 and the N6DN SID corresponding to the second VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the N3RAN community corresponding to the second VRF210 and the N6DN community corresponding to the second VRF220 are stored in the community attribute. The N6DN SID corresponding to the second VRF220 may also be stored in the BGP-LS attribute. Furthermore, for the combination of the second VRF210 and the third VRF220, the SRGW400 stores the N3RAN prefix corresponding to the second VRF210 and the N6DN SID corresponding to the third VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the community of the N3RAN corresponding to the second VRF210 and the community of the N6DN corresponding to the third VRF220 are stored in the community attribute. The N6DN SID corresponding to the third VRF220 may also be stored in the BGP-LS attribute.

[0064] For the combination of the third VRF210 and the first VRF220, the SRGW400 stores the N3RAN prefix corresponding to the third VRF210 and the N6DN SID corresponding to the first VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the community of the N3RAN corresponding to the third VRF210 and the community of the N6DN corresponding to the first VRF220 are stored in the community attribute. The N6DN SID corresponding to the first VRF220 may also be stored in the BGP-LS attribute. Furthermore, for the combination of the third VRF210 and the second VRF220, the SRGW400 stores the N3RAN prefix corresponding to the third VRF210 and the N6DN SID corresponding to the second VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the community of the N3RAN corresponding to the third VRF210 and the community of the N6DN corresponding to the second VRF220 are stored in the community attribute. The N6DN SID corresponding to the second VRF220 may also be stored in the BGP-LS attribute. Furthermore, for the combination of the third VRF210 and the third VRF220, the SRGW400 stores the N3RAN prefix corresponding to the third VRF210 and the N6DN SID corresponding to the third VRF220 in the NLRI attribute within the MP_REACH_NLRI attribute, and generates a GW Discovery Route in which the community of the N3RAN corresponding to the third VRF210 and the community of the N6DN corresponding to the third VRF220 are stored in the community attribute. The N6DN SID corresponding to the third VRF220 may also be stored in the BGP-LS attribute.

[0065] In the second method, the SRGW400 may generate GW Discovery Routes by separating the NLRI types. For example, the NLRI type for storing N3RAN prefixes may be set to Access, and the NLRI type for storing N6DN SIDs may be set to Core. For multiple VRF210s, the SRGW400 may generate a GW Discovery Route with the NLRI type set to Access, storing the N3RAN prefixes in the NLRI within the MP_REACH_NLRI attribute, and storing the N3RAN communities in the community attribute. When there are multiple VRF210s that can access the same UPF120, the N3RAN prefixes of multiple VRF210s may be stored in a single BGP update message that has a common N3RAN community attribute. Furthermore, the SRGW400 may generate a GW Discovery Route for multiple VRF220s, setting the NLRI type to Core, storing the node ID representing the SRGW400 itself in the NLRI attribute of MP_REACH_NLRI, storing the N6DN community in the community attribute, and assigning the N6DN SID. The SRGW400 then advertises the generated GW Discovery Route to the N4BGPC300. The GW Discovery Route may be a BGP-LS Route.

[0066] Here, we will explain using the example where SRGW400 includes a first VRF210, a second VRF210, a third VRF210, a first VRF220, a second VRF220, and a third VRF220.

[0067] SRGW400 may generate a GW Discovery Route with the NLRI type set to Access, storing the N3RAN prefix corresponding to the first VRF210 in the NLRI attribute within the MP_REACH_NLRI attribute, and storing the N3RAN community corresponding to the first VRF210 in the community attribute. Alternatively, SRGW400 may generate a GW Discovery Route with the NLRI type set to Access, storing the N3RAN prefix corresponding to the second VRF210 in the NLRI attribute within the MP_REACH_NLRI attribute, and storing the N3RAN community corresponding to the second VRF210 in the community attribute. Alternatively, SRGW400 may generate a GW Discovery Route with the NLRI type set to Access, storing the N3RAN prefix corresponding to the third VRF210 in the NLRI attribute within the MP_REACH_NLRI attribute, and storing the N3RAN community corresponding to the third VRF210 in the community attribute.

[0068] Furthermore, SRGW400 may generate a GW Discovery Route with the NLRI type set to Core, storing the node ID representing SRGW400 itself in the NLRI attribute within the MP_REACH_NLRI attribute, storing the N6DN community corresponding to the first VRF220 in the community attribute, and assigning the N6DN SID corresponding to the first VRF220. Alternatively, SRGW400 may generate a GW Discovery Route with the NLRI type set to Core, storing the node ID representing SRGW400 itself in the NLRI attribute within the MP_REACH_NLRI attribute, storing the N6DN community corresponding to the second VRF220 in the community attribute, and assigning the N6DN SID corresponding to the second VRF220. Furthermore, SRGW400 may generate a GW Discovery Route with the NLRI type set to Core, storing the node ID representing SRGW400 itself in the NLRI attribute within the MP_REACH_NLRI attribute, storing the community of the N6DN corresponding to the third VRF220 in the community attribute, and assigning the N6DN SID corresponding to the third VRF220.

[0069] In the first method, the N4BGPC300 can determine the combination of VRF210 and VRF220 based on the received GW Discovery Route. In the second method, the N4BGPC300 may configure all combinations of VRF210 and VRF220.

[0070] The N4BGPC300 identifies the DN name corresponding to the matching community attribute in the DN community association table when the community of the N6DN of the GW Discovery Route obtained from the SRGW400 matches any of the community attributes. Then, the N4BGPC300 refers to the DN table association table to identify the DN table pointer corresponding to the identified DN name.

[0071] The N4BGPC300 registers the N3RAN prefixes, N6DN SIDs, and N3RAN communities included in the GW Discovery Route in the DN table indicated by the identified DN table pointer. The N4BGPC300 also registers the information of multiple GW Discovery Routes received from the SRGW400 in the DN table corresponding to each of the multiple DN names. This completes the preparation of the database. The DN table may be a Patricia tree structure with the N3RAN prefix as the key.

[0072] The N4BGPC300 obtains PFCP session information for the UE40 from the SMF110. The N4BGPC300 obtains PFCP session information notified by the SMF110 when the UE40 is attached.

[0073] PFCP session information may include the address of UE40. PFCP session information may include the address of gNB130 housing UE40. PFCP session information may include the address of UPF120 corresponding to UE40. PFCP session information may include the network instance corresponding to UE40. PFCP session information may include the access network instance. PFCP session information may include the core network instance. PFCP session information may include the Core DN name.

[0074] When N4BGPC300 obtains PFCP session information for UE40, it generates routing information destined for UPF120. N4BGPC300 searches the DN table association table using the Core DN name included in the PFCP session information to identify a pointer to the DN table corresponding to the Core DN name, and then identifies the DN table indicated by the pointer. N4BGPC300 then performs a search on the identified DN table using the address of gNB130 (N3RAN prefix) included in the PFCP session information as the key, and identifies the entry for that N3RAN prefix in the DN table. The DN table search may be performed by identifying the N3RAN prefix entry using longest prefix matching.

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

[0076] The N4BGPC300 may use a community attribute that identifies the N6DN VRF in the routing information for UPF120 destination addresses advertised to multiple SRGW400s, each having a different N6DN SID. If the community allows all target SRGW400s to identify the VRF220 as an N6DN VRF, the N4BGPC300 may advertise only one common UPF120 destination address routing piece with the N6DN community attached to all SRGW400s, instead of advertising multiple UPF120 destination address routing pieces with each individual SRGW400 having its corresponding N6DN SID attached. The community attribute that identifies the N6DN may be a Color community. The community attribute that identifies the N6DN may also be a community attribute defined and used with the direct purpose of identifying the N6DN.

[0077] When N4BGPC300 knows the N3RAN community in advance and advertises UPF120-destination route information to SRGW400 that identifies the N6DN VRF by community attribute, it may advertise a UPF120 route with only the community attribute that identifies the N6DN attached, without searching the DN table. In this case, SRGW400 does not need to advertise the GW Discovery Route to N4BGPC300.

[0078] The SRGW400 recognizes that the received routing information is routing information to be imported into the VRF210 of the N3RAN by referring to the community attribute of the routing information, and imports the routing information destined for the UPF120 into the VRF210. As a result, the SRGW400 can acquire packets sent by the UE40 that would conventionally be forwarded to the UPF120 and forward them to the DN30.

[0079] Figure 5 schematically shows an example of the functional configuration of the N4BGPC300 and the logical configuration of the conversion unit 410. The N4BGPC300 comprises a storage unit 312, a generation unit 314, a registration unit 316, a message receiving unit 318, a corresponding information generation unit 320, an information acquisition unit 322, a route information generation unit 324, and an advertising unit 326. The conversion unit 410 comprises a VRF generation unit 422, an advertising unit 424, a route information receiving unit 426, a route setting unit 428, a packet conversion unit 430, and a packet forwarding unit 432.

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

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

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

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

[0084] The VRF generation unit 422 generates VRFs. For example, the VRF generation unit 422 generates multiple gNBVRFs corresponding to each of the multiple gNB130s. VRF210 may be an example of a gNBVRF. For example, the VRF generation unit 422 generates multiple DNVRFs corresponding to each of the multiple DN30s. VRF220 may be an example of a DNVRF.

[0085] The advertising unit 424 advertises the VRF information generated by the VRF generation unit 422 to the N4BGPC 300. The advertising unit 424 advertises a message to the N4BGPC 300 that includes information on multiple gNBVRFs and multiple DNVRFs generated by the VRF generation unit 422, for example. 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 gNBVRF and DNVRF and advertise information for all combinations to the N4BGPC 300. For example, for each of all combinations of multiple gNBVRF and multiple DNVRF, the advertising unit 424 advertises a message to the N4BGPC 300 that stores the N3RAN prefix corresponding to the gNBVRF and the N6DN SID corresponding to the DNVRF in the NRLI, and the N3RAN community corresponding to the gNBVRF and the N6DN community corresponding to the DNVRF in the community attribute.

[0087] As a specific example, the advertising unit 424 stores the N3RAN prefix corresponding to the first gNBVRF and the N6DN SID corresponding to the first DNVRF in the NLRI attribute of the MP_REACH_NLRI attribute for a combination of the first gNBVRF among multiple gNBVRFs and the first DNVRF among multiple DNVRFs, and advertises a message to the N4BGPC300 in which the community of the N3RAN corresponding to the first gNBVRF and the community of the N6DN corresponding to the first DNVRF are stored in the community attribute. The N6DN SID corresponding to the first DNVRF may also be stored in the BGP-LS attribute. The N3RAN prefix corresponding to the first gNBVRF may be the address of one or more gNB130s connected to the first gNBVRF. The N6DN SID corresponding to the first DNVRF may be the SID indicating the first DNVRF in the SRGW400. The SID indicating the first DNVRF may be a common Anycast SID that indicates the first DNVRF present in each of the multiple SRGW400s. Alternatively, the SID indicating the first DNVRF may be the SID of the VRF250 of one or more PE routers 50 connected to the first DNVRF.

[0088] Alternatively, the advertising unit 424 may advertise all gNBVRF and DNVRF information to the N4BGPC 300, and the N4BGPC 300 may configure all combinations of gNBVRF and DNVRF. For example, the advertising unit 424 may advertise to the N4BGPC 300 a message for multiple gNBVRFs with the NLRI type set to Access, storing the N3RAN prefix corresponding to the gBNVRF in the NLRI attribute of MP_REACH_NLRI, and storing the N3RAN community corresponding to the gBNVRF in the community attribute. For multiple GNVRFs, the advertising unit 424 may advertise to the N4BGPC 300 a message with the NLRI type set to Core, storing the node ID indicating SRGW400 in the NLRI attribute of MP_REACH_NLRI, storing the N6DN community corresponding to the GNVRF in the community attribute, and adding the N6DN SID corresponding to the GNVRF.

[0089] As a specific example, advertising unit 424 advertises to N4BGPC300 a message containing the following information: for the first of several gNBVRFs, the NLRI type is set to Access, the N3RAN prefix corresponding to the first gNBVRF is stored in the NLRI attribute of MP_REACH_NLRI, and the N3RAN community corresponding to the first gNBVRF is stored in the community attribute. For the first of several DNVRFs, the NLRI type is set to Core, the node ID indicating SRGW400 is stored in the NLRI attribute of MP_REACH_NLRI, the N6DN community corresponding to the first DNVRF is stored in the community attribute, and the N6DN SID corresponding to the first DNVRF is added.

[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. The correspondence information generation unit 320 identifies the DN name corresponding to the matched community attribute if 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 then refers to the DN related information association information stored in the storage unit 312 and identifies 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 the information of the multiple messages received from the advertising unit 424 in the DN related information corresponding to each of the multiple DN names. In this way, the correspondence information generation unit 320 generates correspondence information. That is, 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 UE40. The information acquisition unit 322 may acquire the PFCP session information of the UE40 from the SMF110. For example, the information acquisition unit 322 acquires the PFCP session information notified by the SMF110 when the UE40 is attached to the mobile network.

[0092] The routing information generation unit 324 generates routing information destined for UPF120 when the information acquisition unit 322 acquires PFCP session information for UE40. Based on the PFCP session information and the correspondence information generated by the correspondence information generation unit 320, the routing information generation unit 324 may generate routing information for the destination address of UPF120 corresponding to UE40, which includes the SID of the DNVRF corresponding to UE40.

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

[0094] As a specific example, if the correspondence information is a DN table, the route information generation unit 324 identifies the DN table corresponding to the DN name, and performs a search on that DN table using the gNB address (N3RAN prefix) included in the PFCP session information as the key, and identifies the entry for that 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 UPF120 in NLRI, the address of N4BGPC300 in Nexthop-Address, adds the N6DN SID in the entry, and generates a BGP update message that stores the community of N3RAN in the entry as the community attribute of the route, and advertises it to the SRGW 400. The advertising unit 326 may be just one example of a route information advertising unit.

[0096] The routing information generation unit 324 may use a community attribute that identifies the N6DN VRF in the routing information for UPF120 destination addresses advertised to multiple SRGW400s, each having a different N6DN SID. If the community allows all target SRGW400s to identify the DNVRF as an N6DN VRF, the advertising unit 326 may advertise only one common UPF120 destination address routing piece with the N6DN community attached to all SRGW400s, instead of advertising multiple UPF120 destination address routing pieces with the N6DN SID corresponding to each individual SRGW400.

[0097] Furthermore, if the advertising unit 326 already knows the N3RAN community and advertises UPF120-bound route information to SRGW400 that identifies the N6DN VRF based on the community attribute, it may advertise the UPF120 route without searching the DN table. In this case, SRGW400 does not need to advertise the GW Discovery Route to N4BGPC300.

[0098] The route information receiving unit 426 receives 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. The route setting unit 428 can recognize that the route information is to be imported into the VRF210 of N3RAN by referring to the community attribute of the received route information. In this case, the route setting unit 428 imports route information with UPF120 as the destination into the VRF210.

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

[0100] The packet forwarding unit 432 performs packet forwarding. The packet forwarding unit 432 forwards packets according to the routing set by the routing unit 428. For example, for a packet sent by UE40 and reaching VRF210 with a destination of UPF120, the packet forwarding unit 432 controls the packet conversion unit 430 to make changes so that it is forwarded to the corresponding DN30 via the corresponding VRF220.

[0101] Figure 6 schematically shows an example of the hardware configuration of computer 1200 functioning as N4BGPC300 or SRGW400. A program installed on computer 1200 can cause computer 1200 to function as one or more "parts" of the apparatus according to this embodiment, or to cause computer 1200 to execute operations associated with the apparatus according to this embodiment or such one or more "parts", and / or to cause computer 1200 to execute a process or a stage of such process according to this embodiment. Such a program may be executed by CPU 1212 to cause computer 1200 to execute 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, 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 communication 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 and a DVD-RAM drive, etc. The storage device 1224 may be a hard disk drive and a solid-state drive, etc. The computer 1200 also includes legacy input / output units such as a ROM 1230 and a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0103] The CPU 1212 operates according to the programs stored in the ROM 1230 and RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires the image data generated by the CPU 1212 and stores it in the frame buffer provided in RAM 1214 or within itself, so that the image data is 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 boot programs and / or hardware-dependent programs of the computer 1200, which are executed by the computer 1200 upon activation. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via USB ports, parallel ports, serial ports, keyboard ports, mouse ports, etc.

[0106] The program is provided on a computer-readable storage medium such as a DVD-ROM or IC card. The program is read from the computer-readable storage medium and installed on a storage device 1224, RAM 1214, or ROM 1230, which are examples of computer-readable storage media, and executed by the CPU 1212. The information processing described within these programs is read by the computer 1200, resulting in coordination between the program and the various types of hardware resources described above. The apparatus or method may be configured to realize the operation or processing of information in accordance with the use of the computer 1200.

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

[0108] Furthermore, the CPU 1212 may read all or necessary parts of a file or database stored on an external recording medium such as the storage device 1224, a DVD drive (DVD-ROM), or an IC card into the RAM 1214, and perform various types of processing on the data in the RAM 1214. The CPU 1212 may then write the processed data back 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 subjected to information processing. The CPU 1212 may perform various types of processing on the data read from RAM 1214, including various types of operations, information processing, conditional judgments, conditional branching, unconditional branching, information retrieval / replacement, etc., as described throughout this disclosure and specified by the program instruction sequence, and write the results back to RAM 1214. The CPU 1212 may also retrieve information in files, databases, etc., within the recording medium. For example, if multiple entries are stored in the recording medium, each having an attribute value of a first attribute associated with an attribute value of a second attribute, the CPU 1212 may search among the multiple entries for an entry that matches the specified condition for the attribute value of the first attribute, read the attribute value of the second attribute stored in that entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies the predetermined condition.

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

[0111] In this embodiment, blocks in the flowchart and block diagram may represent a stage in a process in which an operation is performed or a "part" of a device that has the role of performing an operation. A particular stage and "part" may be implemented by a dedicated circuit, a programmable circuit supplied with computer-readable instructions stored on a computer-readable storage medium, and / or a processor supplied with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuit may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. The programmable circuit may include reconfigurable hardware circuits, such as field-programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), which include logical AND, logical OR, exclusive OR, negated AND, negated OR, 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 to be executed by a suitable device, and as a result, a computer-readable storage medium having instructions stored therein will comprise a product that includes instructions that can be executed to create means for performing operations specified in a flowchart or block diagram. 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 disk read-only memory (CD-ROM), digital multipurpose disc (DVD), Blu-ray® disc, memory stick, integrated circuit card, etc.

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

[0114] Computer-readable instructions may be provided to a general-purpose computer, a special-purpose computer, or a programmable circuit, either locally or via a wide area network (WAN) such as a local area network (LAN) or the internet, so that the computer-readable instructions may be executed by the processor or programmable circuit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, in order to generate means for performing operations specified in a flowchart or block diagram. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

[0115] Although the present invention has been described above using 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 or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0116] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before" or "prior to," and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," and "next," for convenience, this does not mean that it is essential to perform the operations in that 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 Corresponding 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 routing information reception unit, 428 routing 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 graphics controller, 1218 display device, 1220 input / output controller, 1222 communication interface, 1224 storage device, 1230 ROM, 1240 input / output chip

Claims

1. Controller and An SR gateway that converts GTP-U compliant packets received from a mobile network into SRv6 compliant packets. Equipped with, The aforementioned SR gateway is A VRF generation unit that generates multiple gNBVRFs, each corresponding to a multiple gNB, and multiple DNVRFs, each corresponding to a multiple DN. It has, The aforementioned controller, A correspondence information generation unit generates correspondence information that associates multiple gNBVRFs with multiple DNVRFs, An information acquisition unit that acquires PFCP session information notified when a UE is attached, A routing information generation unit generates routing information for the destination address of the UPF corresponding to the UE, which includes the DNVRF community corresponding to the UE, based on the PFCP session information and the correspondence information. Route information advertising unit that advertises the aforementioned route information to the SR gateway A communication system having the following features.

2. The aforementioned communication system includes a router, The SR gateway receives routing information for the destination address of the UPF corresponding to the UE from the controller, The SID corresponding to the DNVRF of the aforementioned router is associated and registered in the gNBVRF. The communication system according to claim 1.

3. A correspondence information generation unit generates correspondence information that associates multiple gNBVRFs, which are VRFs corresponding to each of multiple gNBs, with multiple DNVRFs, which are VRFs corresponding to each of multiple DNs. An information acquisition unit that acquires PFCP session information notified when a UE is attached, A routing information generation unit generates routing information for the destination address of the UPF corresponding to the UE, which includes the DNVRF community corresponding to the UE, based on the PFCP session information and the correspondence information. A route information advertising unit that advertises the aforementioned route information to gateways A controller equipped with the following features.

4. A program for causing a computer to function as the controller described in claim 3.

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