Communication System and Controller

Abstract

A communications system that enables the management of network slices, including IP networks. [Solution] A communication system 10 includes an N4BGPC (N4 Border Gateway Protocol Controller) 300, which is a controller, and an SR gateway 400, which converts SRv6-compliant packets received from an IP network into GTP-U-compliant packets. The SR gateway has a notification unit that notifies the controller and routers connected to the IP network of an AD route that includes an IP prefix containing the address of the connected gNB in ​​the NLRI and the SID of the SR gateway in the BGP attribute. The controller has an advertisement unit that advertises UE route information to routers.

Description

[Technical Field]

[0001] The present invention relates to communication systems. [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 SRv6-compliant packets received from an IP network into GTP-U-compliant packets. The SR gateway may include a notification unit that notifies the controller and a router connected to the IP network of an AD route that includes an IP prefix including the address of the connected gNB in ​​the NLRI and an SID of the SR gateway in a BGP attribute. The controller may include an advertisement unit that advertises, to the router, UE route information included in the PFCP session notified when the UE is attached.

[0004] The notification unit may notify the controller and the router of the AD route including the address of the connected gNB and the SID of the SR gateway through the EP of the NLRI. The advertisement unit may add a community attribute imported by the router to the route information of the UE so that the router receives the route information of the UE and registers a route to the UE in the router's routing table, and advertise the result to the router. The advertisement unit may add the community attribute, which differs for each core network instance included in the PFCP session, to the route information of the UE. The advertisement unit may store an IP prefix including the address of the UE included in the PFCP session, the IP address of the gNB, TEID, and QFI and RQI in at least one of the NLRI and Nexthop-Address in the MP_REACH_NLRI attribute as the route information of the UE.

[0005] The communication system may further include the router, and the router may include an ADRDB, which is a routing table, for searching for AD routes received from the SR gateway. The ADRDB may be a global routing table of the router. The ADRDB may be a VRF that imports the AD routes based on the value of a community attribute added to the AD routes. The router may evaluate the value of a community attribute added to the AD routes based on a community attribute that differs for each group of gNBs registered in advance, and import the AD routes into the ADRDB.

[0006] According to one embodiment of the present invention, there is provided a controller, which may include an advertisement unit that advertises route information of a UE to a router connected to an IP network.

[0007] According to one embodiment of the present invention, there is provided a program for causing a computer to function as the controller.

[0008] According to one embodiment of the present invention, there is provided an information processing method executed by a computer. The information processing method may include a receiving step of receiving, from an SR gateway that converts SRv6-compliant packets received from an IP network into GTP-U-compliant packets, notification information notifying an AD route including an IP prefix including the address of a connected gNB in ​​the NLRI and an SID of the SR gateway in a BGP attribute. The information processing method may include a storage step of storing in a storage unit a VRF prefix including the address of the gNB and the SID of the SR gateway in association with each other. The information processing method may include an advertising step of searching the storage unit using the address of the gNB included in the PFCP session notified when the UE is attached as a key, and, if a match is found, advertising the UE's route information to a router connected to the IP network.

[0009] 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]

[0010] [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 the processing content 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 450. [Figure 4] 10A and 10B show an example of a hardware configuration of a computer 1200 that functions as an N4BGPC 300, an SRGW 400, or an N4BGPC 600. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] The N4BGPC 300 controls the SRGW 400. The N4BGPC 300 may execute processing related to the path control of the SRGW 400.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] In this embodiment, the N4BGPC 300 executes 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 of the UE 40 may be, for example, any communication device such as any server on the Internet.

[0023] 2 is an explanatory diagram for explaining the processing content in the communication system 10. Here, a case will be described in which N4BGPC 300 sets the route information of UE 40 in VRF 220 connected to DN 30, so that packets addressed to UE 40 are forwarded via conversion unit 450.

[0024] The N4BGPC 300 may add a community attribute imported by the VRF 220 to the route information of the UE 40 so that the VRF 220 receives the route information of the UE 40 and registers a route to the UE 40 in the route table of the VRF 220. The community attribute may be an extended community attribute. The extended community attribute may be a route target.

[0025] N4BGPC 300 may store an IP prefix including the UE address of UE 40 included in PFCP session 510, the IP address of gNB 130, a TEID (Tunnel endpoint identifier), a QFI (QoS Flow Identifier), and an RQI (Reflective QoS Indicator) in at least one of the NLRI and Nexthop-Address in the MP_REACH_NLRI attribute as the route information of UE 40. N4BGPC 300 may store an IP prefix including the UE address of UE 40 included in PFCP session 510, the IP address of gNB 130, the TEID, and the QFI and RQI in only the NLRI or Nexthop-Address in the MP_REACH_NLRI attribute, or may store them distributed in both.

[0026] An address family may be defined that can store, as the route information of the UE 40, an IP prefix including the UE address of the UE 40 included in the PFCP session 510, the IP address of the gNB 130, and the TEID in the NLRI and Nexthop of the MP_REACH_NLRI attribute. The new address family to be defined may indicate TEID (4 bytes), QFI+RQI (1 byte), zero (3 bytes), and the IP address of the gNB (4 bytes or 16 bytes) as the encoding of the Nexthop-Address of the MP_REACH_NLRI attribute. Alternatively, it may indicate zero (3 bytes), TEID (4 bytes), QFI+RQI (1 byte), and the IP address of the gNB (4 bytes or 16 bytes) as the encoding of the Nexthop-Address. Alternatively, the NLRI may be encoded as the gNB's IP address (4 bytes or 16 bytes) + QFI and RQI (1 byte) + TEID (2 bytes) + UE IP prefix (4 bytes or 16 bytes), and the Nexthop-Address may indicate that the gNB address is the address of the gNB. Alternatively, the Nexthop-Address may be the loopback address of the accommodating SRGW. The new address family may define a field that indicates a 3GPP (registered trademark) 4G system, a 5G system, or an IETF PMIP system, and indicate that there is a unique encoding for each system indicated by the field.

[0027] This allows a packet addressed to a UE 40 to which a slice is assigned to be sent from the DN 30 to be forwarded to the SRGW 400 in the VRF 220, and the packet converted from SRv6 to GTP-U in the conversion unit 450 is forwarded to the gNB 130 that accommodates the UE 40.

[0028] The UE 40 may be assigned various types of slices, including, but not limited to, ultra-high quality, high quality, medium quality, best effort, and low latency.

[0029] 3 schematically illustrates an example of the functional configuration of N4BGPC 300 and the logical configuration of the conversion unit 450. N4BGPC 300 includes a generation unit 302, a notification unit 304, a storage unit 306, an advertising unit 308, and an acquisition unit 310. N4BGPC 300 may include some, but not all, of these components, or may include other components. The conversion unit 450 includes a packet conversion unit 452, an SR policy storage unit 454, a packet forwarding unit 456, an advertising control unit 458, and a notification unit 460. The conversion unit 450 may include some, but not all, of these components, or may include other components.

[0030] The generation unit 302 generates an SR policy that includes information indicating a conversion function from SRv6 to GTP-U and an SID for the UE in the BSID, and includes the SID of the VRF corresponding to the gNB that accommodates the UE in the EP of the NLRI. The notification unit 304 notifies the SRGW 400 of the SR policy generated by the generation unit 302.

[0031] The packet conversion unit 452 converts packets conforming to SRv6 into packets conforming to GTP-U. The SR policy storage unit 454 stores the SR policy notified by the notification unit 304. When a packet including an SID for a UE is received, the packet forwarding unit 456 identifies the SID of the VRF corresponding to the SID for the UE based on the SR policy stored in the SR policy storage unit 454, and forwards the packet.

[0032] The packet forwarding unit 456 may import the SID of the VRF corresponding to the UPF as a route of the UPF, and when receiving a notification of arrival of a packet to the UE, may forward the notification to the UPF. When the UE transitions to an idle state, the packet forwarding unit 456 may switch forwarding of packets addressed to the UE from forwarding using a longest match to forwarding using a short prefix route.

[0033] The advertisement control unit 458 controls the advertisement of route information to the N4BGPC 300. When advertising route information indicating a gNB route to the N4BGPC 300, the advertisement control unit 458 may control the advertisement to be accompanied by information that can identify that the route is a gNB route, and when advertising route information indicating a UPF route to the N4BGPC 300, the advertisement to be accompanied by information that can identify that the route is a UPF route.

[0034] The notification unit 460 notifies the N4BGPC 300 of an AD route that includes, for example, an IP prefix including the address of the connected gNB 130 and the SID of the SRGW 400 in the NLRI. The notification unit 460 may notify the N4BGPC 300 of an AD route that includes, in the color attribute, slice identification information that can identify a slice corresponding to the UE. The notification unit 460 may notify the PE router 50 having the VRF 220 of the AD route.

[0035] When the notification unit 460 adds the SID of the SRGW 400 to the AD route and notifies the N4BGPC 300, it may not be necessary to add the SID of the SRGW 400 to the AD route to be notified to the PE router 50 having the VRF 220. When the notification unit 460 adds the SID of the SRGW 400 to the AD route and notifies the PE router 50, it may not be necessary to add the SID of the SRGW 400 to the AD route to be notified to the N4BGPC 300. The notification unit 460 may add the SID of the SRGW 400 to both the AD routes to be notified to the N4BGPC 300 and the PE router 50.

[0036] The notification unit 460 may add a different community attribute for each group of gNBs 130 to the route information of the UE 40 in the AD route. An example of a group of gNBs 130 is a group for each region in which the gNBs 130 are deployed. Another example of a group of gNBs 130 is a group for each company. For example, for a group of gNBs 130 deployed within the premises of a company, a community attribute corresponding to the group may be added to the UE 40 route information. The notification unit 460 may register in advance the community attribute for each group of gNBs 130. The notification unit 460 may register in advance which group each of the multiple gNBs 130 belongs to.

[0037] The storage unit 306 stores the VRF 210 and the SID of the SRGW 400 notified by the notification unit 460 in association with each other. The ADRDB 320 may be an example of the storage unit 306. The acquisition unit 310 acquires PFCP session information from the SMF 110. The advertising unit 308 searches the storage unit 306 using the address of the gNB included in the PFCP session notified when the UE is attached as a key, and if there is a match, advertises the route information of the UE to a router connected to the IP network.

[0038] The advertising unit 308 may advertise the route information of the UE 40 to the VRF 220 connected to the DN 30. The advertising unit 308 may advertise the route information of the UE 40 to the PE router 50 having the VRF 220 that accommodates the DN 30.

[0039] The advertising unit 308 may add a community attribute imported by the VRF 220 to the route information of the UE 40 so that the VRF 220 receives the route information of the UE 40 and registers a route to the UE 40 in the route table of the VRF 220. The community attribute may be an extended community attribute. The extended community attribute may be a route target.

[0040] The advertising unit 308 may add a community attribute that differs for each core network instance included in the PFCP session 510 to the route information of the UE 40. The advertising unit 308 may add a community attribute that differs for each group of gNBs 130 included in the PFCP session 510 to the route information of the UE 40. The advertising unit 308 may add a community attribute that corresponds to an access network instance included in the PFCP session 510 to the route information of the UE 40. The advertising unit 308 may add a community attribute that corresponds to an S-NSSAI included in the PFCP session 510 to the route information of the UE 40. The advertising unit 308 may add a community attribute that corresponds to both the access network instance and the S-NSSAI included in the PFCP session 510 to the route information of the UE 40. The N4BGPC 300 may add a community attribute that differs for each piece of information included in the PFCP session 510 to the route information of the UE 40. VRF220 may receive and import UE40 routes with per-purpose community attributes attached, such as per core network instance, per gNB group, per access network instance, and S-NSSAI.

[0041] The advertising unit 308 may store an IP prefix including the UE address of the UE 40 included in the PFCP session 510, the IP address of the gNB 130, the TEID, and the QFI and RQI in at least one of the NLRI and Nexthop-Address in the MP_REACH_NLRI attribute as route information for the UE 40. At this time, the SID value itself corresponding to the conversion unit 450 of the SRGW 400 may be stored as GTP4.E or GTP6.E in the Prefix-SID attribute. Furthermore, multiple MP_REACH_NLRIs for other UEs 40 having the same Prefix-SID attribute may be stored in one BGP update message.

[0042] The PE router 50 having the VRF 220 that accommodates the DN 30 may receive the AD route directly from the SRGW 400. The N4BGPC 300 may advertise the UE 40 route to the PE router 50 without assigning the SID of the SRGW 400 corresponding to the UE 40 to the UE route. In this case, the PE router 50 may associate the SID addressed to the UE 40, which is included in the AD route received from the SRGW 400, with the UE route received from the N4BGPC 300.

[0043] The PE router 50 having the VRF 220 that accommodates the DN 30 may associate the SID of the AD route that has the same color community as the color community of the route to the UE 40 with the SID addressed to the UE 40.

[0044] When N4BGPC300 stores the IP address of gNB130 in MP_REACH_NLRI of the UE40 route, the PE router 50 having the VRF220 accommodating the DN30 may receive the AD route directly from the SRGW400. In this case, N4BGPC300 may advertise the UE40 route to the PE router 50 without assigning the SID of the SRGW400 corresponding to the UE40. In this case, the PE router 50 may associate the UE route received from N4BGPC300 with the SID addressed to UE40 included in the AD route received from the SRGW400.

[0045] The PE router 50 may write the gNB130 address, QFI and RQI, and TEID included in the UE route received from N4BGPC300 into the Argument section of the SID included in the AD route, and update the SID used for forwarding packets addressed to the IP prefix of UE40.

[0046] When an AD route including the IP address of gNB130 disappears from SRGW400, PE router 50 having VRF220 accommodating DN30 may autonomously delete it without waiting for an advertisement of UE40 route deletion from N4BGPC300. PE router 50 may delete all UE routes other than UE40 that are held by the disappeared AD route without waiting for an advertisement of route deletion from N4BGPC300.

[0047] When the AD route from the SRGW 400 including the IP address of the gNB 130 is lost, or when the AD route advertised by an SRGW other than the SRGW 400 is determined to be optimal as the AD route of the route information for the UE 40, the PE router 50 may autonomously associate the SID addressed to the UE 40 with the SID of the optimal AD route without waiting for an advertisement of a UE 40 route update from the N4BGPC 300. The optimality of the AD route may be determined by, for example, a longest prefix match using a Patricia tree.

[0048] The PE router 50 may include an ADRDB for searching for AD routes received from the SRGW 400. The ADRDB in the PE router 50 may be a routing table. The routing table of the ADRDB may be a global routing table of the PE router 50. Alternatively, the ADRDB may be a VRF that imports AD routes based on the value of a community attribute added to the AD route. The PE router 50 may evaluate the value of the community attribute added to the AD route based on a community attribute that differs for each group of gNBs 130 registered in advance, and import the AD route into the ADRDB.

[0049] 4 schematically illustrates an example of the hardware configuration of a computer 1200 functioning as the N4BGPC 300, the SRGW 400, the N4BGPC 600, or the PE router 700. 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 to perform operations associated with the apparatus according to the present embodiment or one or more “parts” thereof, and / or 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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]

[0065] 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, 300 N4BGPC, 302 generation unit, 304 notification unit, 306 storage unit, 308 advertisement unit, 310 acquisition unit, 320 ADRDB, 400 SRGW, 410 conversion unit, 450 conversion unit, 452 packet conversion unit, 454 SR policy storage unit, 456 packet forwarding unit, 458 advertisement control unit, 460 notification unit, 510 PFCP session, 600 N4BGPC, 700 PE router, 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. A controller; an SR gateway that converts SRv6-compliant packets received from an IP network into GTP-U-compliant packets; Equipped with The SR gateway includes: A notification unit that notifies the controller and a router connected to the IP network of route information including an IP prefix including an address of a connected gNB and an SID of the SR gateway in a BGP attribute. having The controller: An advertisement unit that advertises route information of the UE to the router. A communication system comprising:

2. 2. The communication system according to claim 1, wherein the advertising unit adds a community attribute imported by the router to the route information of the UE and advertises the same to the router so that the router receives the route information of the UE and registers a route to the UE in the router's route table.

3. The advertising unit stores an IP prefix including the address of the UE contained in the information about the mobile network, the IP address of the gNB, and the TEID as route information for the UE in at least one of the NLRI and Nexthop-Address in the MP_REACH_NLRI attribute. The communication system described in claim 1 or 2.

4. The communication system according to claim 3 , wherein the advertisement unit further stores a QFI or a QFI and an RQI as the route information of the UE.

5. The router further comprises:

5. The communication system according to claim 1, wherein the router includes an ADRDB that is a routing table for searching an AD (Auto-Discovery) route received from the SR gateway.

6. The communication system of claim 5 , wherein the ADRDB is a global routing table of the router.

7. The communication system according to claim 5 , wherein the ADRDB is a VRF that imports the A-D route according to a value of a community attribute added to the A-D route.

8. The router updates the Argument portion of the SID included in the A-D route received from the notification unit using the gNB address and TEID included in the route information of the UE received from the advertising unit, and generates an SID to be used for packet forwarding to the IP prefix of the UE. The communication system described in any one of claims 5 to 7.

9. The communication system according to claim 8, wherein the router uses the QFI, or the QFI and RQI, contained in the route information of the UE received from the advertising unit to update the Argument portion of the SID contained in the A-D route received from the notification unit, and generates an SID to be used for forwarding packets addressed to the IP prefix of the UE.

10. The notification unit notifies the controller and the router connected to the IP network of an A-D route that includes the IP prefix including the address of the connected gNB and the SID of the SR gateway in a BGP attribute. The communication system described in claim 1.

11. The notification unit notifies the controller and the router connected to the IP network of the A-D route, the A-D route including the SID of the SR gateway in the BGP attribute of the A-D route and the NLRI of the A-D route including an IP prefix including the address of the connected gNB. The communication system described in claim 10.

12. A controller, Advertise the UE's route information to a router connected to the IP network by including it in a BGP attribute; The route information of the UE includes at least an IP prefix including the address of the UE included in the information about the mobile network, a gNB address, and a TEID; controller.

13. The UE's route information further stores a QFI or a QFI and an RQI; The controller of claim 12.

14. A controller; an SR gateway that converts SRv6-compliant packets received from an IP network into GTP-U-compliant packets; Equipped with The controller: An advertising unit that advertises route information of the UE, including the address of the gNB to which the UE is connected, to the SR gateway. having The SR gateway includes: A route table that receives the route information of the UE and registers a route to the UE A communication system comprising:

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