Packet forwarding device, packet forwarding method, and program

Abstract

In order to enable packets to be transferred in an appropriate sequence, this packet transferring device (1) comprises: an acquisition means (11) that acquires uplink packets received from a terminal device; an allowable time determining means (12) that refers to the time information included in the header information of the uplink packets, thereby determining an allowable time of delay of the uplink packets; and a sequence determining means (13) that determines a transmission sequence of the uplink packets on the basis of the allowable time of delay.

Description

[Technical Field]

[0001] The present invention relates to a packet forwarding device, a packet forwarding method, and a program. [Background technology]

[0002] In recent years, various packet forwarding devices that perform packet forwarding processing according to Quality of Service (QoS) in network slices have been developed. Related technologies include the inventions disclosed in the following patent documents.

[0003] The user data processing device described in Patent Document 1 analyzes received packets, identifies the network slice and QoS class to which the received packets belong, and allocates them to queues according to the analysis results of the received packets.The user data processing device then acquires the received packets from queues corresponding to each class of the corresponding queue group, and performs packet forwarding processing on the acquired received packets according to the QoS.

[0004] Furthermore, the base station device described in Patent Document 2 uses a measurement packet in which the transmission time is recorded to measure the delay time from when the measurement packet is transmitted from the transmitting device to when it is received by the receiving unit, and calculates an allowable time, which is a value obtained by subtracting the delay time from an upper limit.The base station then transmits the transmission packet to a terminal before the allowable time has elapsed since the transmission packet was received by the receiving unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-170729 [Patent Document 2] Japanese Patent Publication No. 2012-119810 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the user data processing device described in Patent Document 1 does not prioritize processing with a focus on delay time. Therefore, when a user data processing device simultaneously receives a packet with a margin for delay time and a packet with a margin for delay time, the user data processing device may prioritize the packet transfer process with a margin for delay time, which may result in the device being unable to satisfy the 5GS delay time requirement required to satisfy the delay time between end devices (terminal devices).

[0007] Furthermore, the base station described in Patent Document 2 is equipped with a mechanism for setting and evaluating target values for delay times assigned to devices included in the network in QCI units. However, because Patent Document 2 relates to a base station, the operation when the target delay time is not met differs from that of a packet forwarding device, and the internal processing order is not changed, so there is a possibility that data cannot be transmitted within the target delay time.

[0008] One aspect of the present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a technique that enables packets to be transferred in an appropriate order. [Means for solving the problem]

[0009] A packet forwarding device according to one embodiment of the present invention comprises an acquisition means for acquiring an upstream packet received from a terminal device, an allowable time determination means for determining an allowable delay time for the upstream packet by referring to time information contained in the header information of the upstream packet, and an order determination means for determining the transmission order of the upstream packet based on the allowable delay time.

[0010] A packet forwarding method according to one aspect of the present invention acquires an upstream packet received from a terminal device, determines an allowable delay time for the upstream packet by referring to time information contained in the header information of the upstream packet, and determines the transmission order of the upstream packet based on the allowable delay time.

[0011] A program according to one aspect of the present invention causes a computer to perform the following processes: acquiring an upstream packet received from a terminal device; determining an allowable delay time for the upstream packet by referring to time information contained in the header information of the upstream packet; and determining the transmission order of the upstream packet based on the allowable delay time. [Effects of the Invention]

[0012] According to one aspect of the present invention, packets can be transferred in the correct order. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram showing an example of the configuration of a packet forwarding device according to a first exemplary embodiment of the present invention. [Figure 2] 3 is a flowchart showing the flow of a packet forwarding method of the packet forwarding device according to the first exemplary embodiment of the present invention. FIG. [Figure 3] FIG. 10 is a diagram illustrating an example of the configuration of a TSN logical bridge including a packet forwarding device according to a second exemplary embodiment of the present invention. [Figure 4] FIG. 1 is a diagram illustrating a protocol stack in U-Plane communication. [Figure 5] FIG. 10 is a block diagram showing an example of the configuration of a packet forwarding device according to a second exemplary embodiment of the present invention. [Figure 6] FIG. 1 is a diagram for explaining time synchronization in UPF / NW-TT. [Figure 7] FIG. 10 is a flowchart showing the overall flow of a packet forwarding method of a packet forwarding device according to a second exemplary embodiment of the present invention. [Figure 8] 8 is a flowchart illustrating details of the delay evaluation process shown in FIG. 7. [Figure 9] 10A and 10B are diagrams for explaining a delay time and a target delay time specified by a delay evaluation unit. [Figure 10] FIG. 10 is a diagram illustrating an example of a target delay time set in a target delay time information table. [Figure 11]8 is a flowchart illustrating details of the transfer process shown in FIG. 7. [Figure 12] 3 is a diagram illustrating an example of the configuration of transmission queues of a first transmission unit and a second transmission unit. FIG. [Figure 13] 1A and 1B are diagrams illustrating the formats of a GTP-U packet and an IP packet. [Figure 14] FIG. 1 is a diagram illustrating a GTP extension header. [Figure 15] FIG. 10 is a diagram for explaining session processing in UPF. [Figure 16] FIG. 1 is a block diagram illustrating a configuration of a computer that functions as a packet forwarding device according to each exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Exemplary Embodiment 1 A first exemplary embodiment of the present invention will be described in detail with reference to the drawings. This exemplary embodiment is a basic form of the exemplary embodiments described below. Note that the drawing reference symbols added to this overview are added to each element for convenience as an example to facilitate understanding, and are not intended to limit the present invention to the illustrated form. Furthermore, connection lines between blocks in the drawings and the like referred to in the following description include both bidirectional and unidirectional lines. Unidirectional arrows are used to schematically indicate the flow of main signals (data) and do not exclude bidirectionality. Furthermore, the connection points of inputs and outputs of each block in the drawings may be configured to include ports or interfaces, but these configurations are not shown in the drawings.

[0015] <Packet forwarding device 1 according to exemplary embodiment 1> 1 is a block diagram showing an example of the configuration of a packet forwarding device 1 according to a first exemplary embodiment of the present invention. As shown in FIG. 1, the packet forwarding device 1 according to this exemplary embodiment includes an acquisition unit 11, an allowable time determination unit 12, and an order determination unit 13.

[0016] The packet forwarding device 1 corresponds to, for example, a UPF / NW-TT (User Plane Function / Network-Side TSN Translator), which is one of multiple nodes called NFs (Network Functions) of the 5GS (5th Generation Mobile Communication System).

[0017] The acquisition unit 11 acquires an uplink packet received from a terminal device. For example, the acquisition unit 11 acquires an uplink packet received from a terminal device via a TSN (Time Sensitive Networking) network or a gNB (next generation NodeB).

[0018] TSN is a standard technology defined by IEEE 802.1Q to enable deterministic messaging over standard Ethernet. TSN technology uses centrally managed, time-scheduled scheduling to guarantee delivery and minimize jitter for real-time applications that require determinism.

[0019] The allowable time determination means 12 determines the allowable delay time for an upstream packet by referring to time information included in the header information of the upstream packet. For example, the allowable time determination means 12 determines the allowable delay time for an upstream packet by referring to time information included in a GTP (GPRS Tunneling Protocol) extension header. The allowable delay time is a value indicating how much delay time there is with respect to a target delay time, and is, for example, a value obtained by subtracting the current delay time from the target delay time.

[0020] GTP is a protocol standardized by GPRS in 1998, but is now also used in the user plane of 5GC. As networks evolve, some extensions to GTP are required to support the N9 and N3 base points of 5GC.

[0021] As increasingly complex QoS features are introduced in 5GC, specific information needs to be signaled on a packet-by-packet basis. In previous generations of mobile networks, traffic can be differentiated by different Tunnel Endpoint Identifiers (TEIDs), but not on a packet-by-packet basis.

[0022] The QoS extensions in 5GC mean that the gNodeB's UPF must set a QoS flow identifier per packet, and each packet must include a delay measurement or signal indicating that reflective QoS is being used. Therefore, GTP had to be extended. GTP supports extension headers, which are leveraged to add a PDU session container to the extension header of GTP packets.

[0023] The time information includes, for example, the gNB transmission time indicated by the UL Sending Timestamp in the UL PDU SESSION INFORMATION (PDU Type 1) in the GTP extension header, and the delay measurement result between the UE (User Equipment) and the gNB indicated by the UL Delay Result.

[0024] The order determination means 13 determines the transmission order of the upstream packets based on the allowable delay time. For example, the order determination means 13 may assign an earlier transmission order to a packet with a relatively short allowable delay time, and a later transmission order to a packet with a relatively long allowable delay time.

[0025] <Effects of Packet Forwarding Device 1> As described above, according to the packet forwarding device 1 of this exemplary embodiment, the order determination means 13 determines the transmission order of upstream packets based on the allowable delay time, so that packets can be forwarded in an appropriate order based on the time information of the packets.

[0026] <Flow of packet forwarding method by packet forwarding device 1> A description will be given of the flow of the packet transfer method executed by the packet transfer device 1 configured as described above, with reference to FIG. 2. FIG. 2 is a flowchart showing the flow of the packet transfer method. As shown in FIG. 2, the packet transfer method includes steps S1 to S3.

[0027] First, the acquisition means 11 acquires an uplink packet received from the terminal device (S1). For example, the acquisition means 11 acquires an uplink packet received from the terminal device via the TSN network or the gNB.

[0028] Next, the allowable time determination means 12 determines the allowable time for the delay of the uplink packet by referring to the time information included in the header information of the uplink packet (S2). For example, the allowable time determination means 12 determines the allowable time for the delay of the uplink packet by referring to the time information included in the GTP extension header.

[0029] Finally, the order determination means 13 determines the transmission order of the uplink packets based on the allowable time for the delay (S3). For example, the order determination means 13 prioritizes the transmission order of packets with a relatively small allowable time for the delay and delays the transmission order of packets with a relatively large allowable time for the delay.

[0030] <Effect of the Packet Transfer Method> As described above, according to the packet transfer method according to this exemplary embodiment, since the order determination means 13 determines the transmission order of the uplink packets based on the allowable time for the delay, the packets can be transferred in an appropriate order based on the time information of the packets.

[0031] 〔Exemplary Embodiment 2〕 A second exemplary embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions as those described in Exemplary Embodiment 1 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0032] <Configuration Example of the TSN Logic Bridge 100> 3 is a diagram showing an example of the configuration of a TSN logical bridge 100 including a packet forwarding device 1A according to a second exemplary embodiment of the present invention. The TSN logical bridge 100 includes a plurality of nodes called NFs (Network Functions) and inter-NF interfaces N1 to N5, N7 to N11, N30, N33, and N52.

[0033] The TSN logical bridge 100 includes a UPF / NW-TT (Network Side-TSN Translator) 1, a DS-TT (Device Side-TSN Translator) 2, a UE 3, an (R)AN (Radio Access Network) 4, an AMF (Access and Mobility Function) 5, an SMF (Session Management Function) 6, a PCF (Policy Control Function) 7, a TSN AF (Application Function) 8, a UDM (User Data Management) 9, and an NEF (Network Exposure Function) 10.

[0034] The UPF1-1 is an NF that functions as an external PDU (Protocol Data Unit) session point for interconnection to a DN (Data Network) and performs packet routing, forwarding, and the like.

[0035] The ports of NW-TT1-2 support connections to the TSN system 300 and forward traffic to the appropriate output ports based on the traffic forwarding information.

[0036] A port of the DS-TT2 is associated with a PDU session that provides a connection to the TSN system 200. There is only one PDU session per port of the DS-TT2. All PDU sessions connecting to the same TSN network through a specific UPF1-1 are grouped into a single 5GS bridge.

[0037] The UE 3 is connected to a RAN or AN (Access Network) 4 and an AMF 5. The UE 3 corresponds to, for example, a terminal device.

[0038] RAN4 is a base station that uses a new RAT (Radio Access Technology), and AN4 is a base station that uses non-3GPP access, such as a Wi-Fi (registered trademark) access point.

[0039] The AMF5 is an NF that provides authentication, authorization, mobility management, etc. for the UE3, and controls the SMF6. The SMF6 is also responsible for UE3 session management, IP address allocation, and selection and control of the UPF / NW-TT1 for data transfer. When the UE3 establishes multiple sessions, the SMF6 manages each session independently and can assign a different SMF6 to each session so that different functions can be used for each session. In 5GC, management related to the UE3 is performed by a single AMF5, and traffic is handled by an SMF6 for each individual network slice.

[0040] The PCF7 is an NF that determines policies related to mobility management and session management to ensure that the AMF5 and SMF6 operate appropriately. The TSN AF8 is an NF that provides information about packet flows to the PCF7, which performs policy control, in order to support QoS (Quality of Service). The PCF7 determines policies related to mobility management and session management based on the packet flow information provided by the TSN AF8.

[0041] UDM9 is an NF that stores and manages UE3 contract information. NEF10 is an NF that exposes a series of management functions, such as adding and deleting groups and members, and various changes, as well as functions for dynamically managing group data.

[0042] Figure 4 is a diagram showing protocol stacks in U-Plane communication. For example, UE / DSTT shown in Figure 4 indicates the protocol stack of DS-TT2 and UE3 on the device side shown in Figure 3. 5G-AN shown in Figure 4 indicates the protocol stack of AN4 shown in Figure 3. UPF shown in Figure 4 indicates the protocol stack of UPF1-1 shown in Figure 3. Furthermore, UPF / NWTT shown in Figure 4 indicates the protocol stack of UPF / NW-TT1 shown in Figure 3.

[0043] <Packet forwarding device 1A according to exemplary embodiment 2> 5 is a diagram showing the configuration of a packet forwarding device 1A according to a second exemplary embodiment of the present invention. As shown in FIG. 5, the packet forwarding device 1A according to this exemplary embodiment includes an acquisition unit 11, an allowable time determination unit 12, an order determination unit 13, a PFCP (Packet Forwarding Control Protocol) control unit 101, a session information table 102, a target delay time information table 103, a distribution unit 108, a low-latency receiving queue 109, a non-low-latency receiving queue 110, a first transmitting unit 113, a second transmitting unit 114, a first transmitting port 115, and a second transmitting port 116.

[0044] The acquisition means 11 includes a first receiving port 104 and a second receiving port 105. The allowable time determination means 12 includes an analysis unit 106 and a delay evaluation unit 107. The order determination means 13 includes a first transfer processing unit 111 and a second transfer processing unit 112.

[0045] The first receiving port 104, the second receiving port 105, the first transmitting port 115, and the second transmitting port 116 are configured by Ethernet (registered trademark) interface ports.

[0046] The PFCP control unit 101 receives a PFCP signal from the SMF 6 and stores PFCP information in a session information table 102. The session information table 102 is a table for managing session information such as PFCP information. The target delay time information table 103 is a table for managing the target delay time of packets.

[0047] The analysis unit 106 analyzes the header of the received packet and identifies an action to be taken for the received packet based on session information such as PFCP information stored in the session information table 102. Details of the analysis unit 106 will be described later.

[0048] The delay evaluation unit 107 evaluates the delay time of packets received from a terminal device for each QoS flow. If the evaluation result of the QoS flow indicates that the QoS flow has no margin for delay time, the delay evaluation unit 107 records that information in the session information table of the packet. Details of the delay evaluation unit 107 will be described later.

[0049] Based on the header analysis result, the allocating unit 108 allocates packet data on a packet-by-packet basis to the receiving queues 109 and 110. Specifically, the allocating unit 108 stores low-latency packet data in the low-latency receiving queue 109, and stores other packet data in the other receiving queues 110.

[0050] The receiving queue 109 is a queue for temporarily storing low-latency packet data before processing by the first transfer processing unit 111, and has a data structure with a flag indicating that there is no margin for delay time. The allocating unit 108 sets the flag to "1" for packets that fall under a QoS flow with no margin for delay time. The receiving queue 109 has a 0th receiving queue 109-1 in the direction from UE3 to UPF1-1, and a 1st receiving queue 109-2 in the direction from UPF1-1 to UE3.

[0051] The second receiving queue 110 is a queue for temporarily storing packet data other than low-latency packet data before processing by the second forwarding processing unit 112.

[0052] The first transfer processing unit 111 retrieves a packet from the low-delay receiving queue 109 , replaces the header with a header that matches the destination network, and stores the packet in the sending queue of the first sending unit 113 or the second sending unit 114 .

[0053] The second transfer processing unit 112 takes out packets from the non-low latency receiving queues 110, replaces the header with a header that matches the destination network, and stores the packets in the sending queue of the first sending unit 113 or the second sending unit 114.

[0054] The first transmitting unit 113 has a transmission queue 113-1 that complies with IEEE802.1Q, and transmits data stored in the transmission queue 113-1 via the first transmission port 115 and the TSN network 400-2.

[0055] The second transmitting unit 114 has a transmission queue 114-1 that complies with IEEE802.1Q, and transmits data stored in the transmission queue 114-1 via the second transmitting port 116 and the gNB 600.

[0056] Figure 6 is a diagram for explaining time synchronization in UPF / NW-TT1. UPF1-1 performs time synchronization between devices in the 5GS network. In Figure 6, UPF1-1 performs time synchronization between UE#A3-1, gNB#A500-1, and UPF1-1, and time synchronization between UE#B3-2, gNB#B500-2, and UPF1-1.

[0057] Furthermore, the NW-TT1-2 performs time synchronization between the TSN domain 1 at the site A 700-1 and the site B 700-2 and the domain 1 at the site C 800-1. Similarly, the NW-TT1-2 performs time synchronization between the TSN domain 2 at the site A 700-1 and the domain 2 at the site D 800-2.

[0058] 7 is a flow diagram showing the overall flow of a packet forwarding method of the packet forwarding device 1A according to the second exemplary embodiment of the present invention. First, the acquisition means 11 acquires upstream packets received by the first receiving port 104 and the second receiving port 105 (S11). Then, the acquisition means 11 records the reception times at which the upstream packets were received (S12).

[0059] Next, the analysis unit 106 analyzes the header of the acquired uplink packet and identifies an action for the uplink packet by referring to the PFCP session information stored in the session information table 102 (S13). Specifically, the analysis unit 106 identifies which slice the uplink packet belongs to in order to perform processing equivalent to the PFCP session lookup and PDR lookup specified in TS29.244 and to perform allocation for each slice.

[0060] Next, the analysis unit 106 determines whether the header of the uplink packet includes the transmission time of the gNB 500 indicated by the UL transmission timestamp in the UL PDU SESSION INFORMATION (PDU Type 1) in the GTP extension header, and the delay measurement result between UE 3 and gNB 500 indicated by the UL delay result (S14).

[0061] If the header includes the transmission time of the gNB 500 and the delay measurement result between the UE 3 and the gNB 500 (S14, Yes), the delay evaluation unit 107 evaluates the delay time for each QoS flow for the uplink packets transmitted from the UE 3. If the evaluation result indicates that the QoS flow has no margin for delay time, the delay evaluation unit 107 records this information in the corresponding packet stored in the session information table 102 (S15), and the process proceeds to step S16. Details of the delay evaluation process (S15) will be described later.

[0062] In step S16, the allocating unit 108 allocates packet data to the receiving queue 109 or 110 on a packet-by-packet basis based on the header analysis result. Specifically, the allocating unit 108 stores low-latency packet data in the low-latency receiving queue 109, and stores non-low-latency packet data in the non-low-latency receiving queue 110. At this time, the allocating unit 108 refers to the session information table 102, and sets a flag of "1" for packets that correspond to a QoS flow with no leeway in delay time.

[0063] Next, the first transfer processing unit 111 extracts the packet data stored in the receiving queue 109 in units of multiple packets (for example, 16 packets), and stores them in the first transmission unit 113 or the second transmission unit 114. At this time, if the flag "1" indicating that the QoS flow has no leeway in delay time is set, the first transfer processing unit 111 rearranges the order of the packet data (S17). Details of the transfer processing (S17) will be described later.

[0064] Next, the first transmitter 113 or the second transmitter 114 retrieves the packet data from the transmission queue 113-1 or 114-1 according to the priority and performs transmission processing (S18). Finally, the first transmission port 115 or the second transmission port 116 transmits the upstream packet to the TSN network 400-2 or the gNB 600 (S19).

[0065] <Details of the Lazy Evaluation Process (S15)> Fig. 8 is a flowchart for explaining the details of the delay evaluation process (S15) shown in Fig. 7. First, the allowable time determination means 12 identifies the first delay time, which is the delay time from the terminal device to the base station, by referring to the UL delay result information included in the header information.

[0066] Specifically, the delay evaluation unit 107 of the allowable time determination means 12 determines the first delay time by referring to the delay measurement result between the UE (terminal device) 3 and the gNB 500 indicated by the UL Delay Result in the UL PDU SESSION INFORMATION (PDU Type 1) in the GTP extension header.

[0067] In addition, the allowable time determination means 12 determines the second delay time, which is the delay time from the base station to the packet forwarding device, by referring to the UL transmission timestamp included in the header information and the reception time of the upstream packet by the packet forwarding device.

[0068] Specifically, the delay evaluation unit 107 of the permissible time determination means 12 identifies the second delay time by referring to the sending time of the gNB indicated by the UL Sending Timestamp of the UL PDU SESSION INFORMATION (PDU Type 1) of the GTP extension header and the receiving time recorded in step S12 (S21). For example, the second delay time is the difference between the receiving time of the uplink packet and the sending time of the gNB.

[0069] Fig. 9 is a diagram for explaining the delay time and target delay time identified by delay evaluation section 107. The one-way delay time between UE and gNB shown in Fig. 9 (1) corresponds to the above-mentioned first delay time, and the one-way delay time between gNB and UPF shown in Fig. 9 (2) corresponds to the above-mentioned second delay time.

[0070] Next, the delay evaluation unit 107 of the allowable time determination means 12 derives a target delay time (S22). The delay evaluation unit 107 refers to the target delay time information table 103 to find the allowable delay time between the UE and the gNB and the delay time between the gNB and the UPF that correspond to the QoS flow ID added to the GTP extension header of the corresponding uplink packet. These values are preset in the target delay time information table 103, and for example, 80% of the fixed value defined in 3GPP TS23.501 is used as the target value.

[0071] Fig. 10 is a diagram showing an example of target delay times set in the target delay time information table 103. As shown in Fig. 10, a resource type, packet delay budget, CN packet delay budget, UE-UPF target delay, and gNB-UPF target delay are set for each QoS flow ID. The resource type indicates the type of packet, such as GBR (Guaranteed Bit Rate), low-delay GBR, etc.

[0072] The Packet Delay Budget shown in (3) of Fig. 9 corresponds to the Packet Delay Budget shown in Fig. 10 and indicates the target delay time between the UE and the UPF. The 5G AN Delay Budget shown in (4) of Fig. 9 indicates the target delay time between the UE and the gNB. Furthermore, the CN Packet Delay Budget shown in (5) of Fig. 9 corresponds to the CN Packet Delay Budget shown in Fig. 10 and indicates the target delay time between the gNB and the UPF.

[0073] As shown in Fig. 10, the UE~UPF target delay is set to a value that is 80% of the Packet Delay Budget. Also, as shown in Fig. 10, the gNB~UPF target delay is set to a value that is 80% of the CN Packet Delay Budget.

[0074] Next, the delay evaluation unit 107 of the allowable time determination means 12 determines the allowable delay time by comparing the sum of the first delay time and the second delay time with the target delay time. For example, the delay evaluation unit 107 of the allowable time determination means 12 determines the allowable delay time as the target delay time minus the sum of the first delay time and the second delay time.

[0075] The delay evaluation unit 107 determines whether the allowable delay time is equal to or less than a predetermined value. For example, if the predetermined value is 0, the delay evaluation unit 107 determines whether the delay time (the sum of the first delay time and the second delay time) is equal to or less than the target delay time (S23). If the delay time is equal to or less than the target delay time (the allowable delay time is equal to or greater than the predetermined value "0") (S23, Yes), the process ends.

[0076] Furthermore, if the delay time is greater than the target delay time (if the allowable delay time is less than the predetermined value "0") (S23, No), the session information table 102 stores the information that the upstream packets of the session are in a session with no leeway in delay time (S24), and the process ends.

[0077] Fig. 11 is a flowchart for explaining the details of the transfer process (S17) shown in Fig. 7. First, the first transfer processing unit 111 extracts packet data stored in the receiving queue 109 in units of multiple packets (for example, 16 packets) (S31).

[0078] Next, the first transfer processing unit 111 determines whether or not there is packet data with a flag "1" set, indicating that the QoS has no margin for delay time, among the extracted packets (S32). If there is no packet data with no margin for delay time (S32, No), the process proceeds to step S36.

[0079] Furthermore, if there is packet data with no leeway in delay time (S32, Yes), the first transfer processing unit 111 of the order determination means 13 swaps an upstream packet that is sent first and has a relatively large allowable delay time with an upstream packet that is sent later and has a relatively small allowable delay time. For example, the first transfer processing unit 111 moves packets with no leeway in delay time (for example, packets with an allowable delay time of 0 or less) forward (places them earlier in order), and moves packets with leeway in delay time (for example, packets with an allowable delay time of 0 or more) later in order (S33).

[0080] The first transmitting unit 113 and the second transmitting unit 114 are provided corresponding to the priority of packets, and include a plurality of transmission queues (transmission queue means) 113-1 and 114-1 for storing packets to be transmitted.

[0081] Upstream packets in a TSN network are configured as Ethernet (registered trademark) frames, and a CoS (Class of Service) is set in the TAG field. This CoS value indicates the priority of the upstream packet, and the first forwarding processing unit 111 and the second forwarding processing unit 112 basically determine the priority of the transmission queue in which to store the packet depending on the CoS value.

[0082] Fig. 12 is a diagram showing an example of the configuration of transmission queues 113-1 and 114-1 of the first transmission unit 113 and the second transmission unit 114. As shown in Fig. 12, the transmission queues 113-1 and 114-1 have queues #1 to #3, with queue #3 being a high-priority queue, queue #2 being a medium-priority queue, and queue #1 being a low-priority queue.

[0083] Priority is assigned to packets according to the above-mentioned CoS value, and here one of Priority 0 to 7 is set. Priority 0 is the highest priority and Priority 7 is the lowest priority. Packets with Priority 0 to 3 are stored in high priority queue #3, packets with Priority 4 to 5 are stored in medium priority queue #2, and packets with Priority 6 to 7 are stored in low priority queue #1.

[0084] Furthermore, each of queues #1 to #3 has information indicating its availability; for example, queue #3 stores the number of free cycles A1 in which a 500-byte packet can be transmitted, and the number of free cycles A2 in which a 1500-byte packet can be transmitted.

[0085] The first transfer processing unit 111 of the order determination means 13 schedules the rearranged uplink packets in order, and stores the uplink packets in one of a plurality of transmission queues (transmission queue means).

[0086] If the allowable delay time for an upstream packet is equal to or less than a predetermined value, the first transfer processing unit 111 of the order determination means 13 determines whether there is space in a transmission queue (transmission queue means) corresponding to a priority higher than the priority previously assigned to the upstream packet (S34).If there is space in the transmission queue (S34, Yes), the priority (CoS) value is changed to a value with a higher priority (S35).

[0087] Next, the first transfer processing unit 111 refers to the session information table 102, performs an action such as header conversion processing on the upstream packet (S36), and stores the upstream packet in the transmission queue 113-1 or 114-1. At this time, the first transfer processing unit 111 of the order determination means 13 stores the upstream packet in the transmission queue (transmission queue means) corresponding to the changed priority (S37).

[0088] 13 is a diagram showing the formats of a GTP-U packet and an IP packet. A GTP-U packet includes an Application, an Inner IP, a GTP-U Extension, a GTP-U, a User Datagram Protocol (UDP), an Outer IP, an Outer L2, and an L1 (Layer 1). An IP packet includes an Application, an Inner IP, an L2, and an L1.

[0089] Fig. 14 is a diagram showing a GTP extension header. The packet forwarding device 1A according to this exemplary embodiment uses only the UL Sending Timestamp and UL Delay Result of the UL PDU SESSION INFORMATION (PDU Type 1) shown in Fig. 14. Here, detailed description of other GTP extension headers will not be provided.

[0090] Figure 15 is a diagram illustrating session processing in UPF1-1. UPF1-1 performs processing equivalent to a PFCP session lookup specified in TS29.244 (S41) and a PDR (Packet Detection Rule) lookup (S42). PFCP achieves packet processing by combining various rules (FAR (Forwarding Action Rule), BAR (Buffering Action Rule), QER (QoS Enforcement Rule), and URR (Usage Reporting Rule)) based on the PDR. If a packet matches the PDR conditions, the packet is processed according to the specified rules (S43).

[0091] <Advantages of the Packet Forwarding Device 1A According to the Second Exemplary Embodiment> As described above, according to the packet forwarding device 1A of this exemplary embodiment, the delay evaluation unit 107 determines the allowable delay time by comparing the sum of the first delay time and the second delay time with the target delay time, so that the allowable delay time can be easily determined.

[0092] Furthermore, the delay evaluation unit 107 determines the allowable delay time as the target delay time minus the sum of the first delay time and the second delay time, so that the allowable delay time can be easily determined.

[0093] Furthermore, the first transfer processing unit 111 swaps an upstream packet that is sent first and has a relatively large allowable delay time with an upstream packet that is sent later and has a relatively small allowable delay time, so that the upstream packet with a relatively small allowable delay time can be transmitted preferentially.

[0094] Furthermore, the first transfer processing unit 111 schedules the rearranged uplink packets in order and stores the uplink packets in one of the multiple queues #1 to #3, so that uplink packets with a relatively short allowable delay time can be scheduled preferentially.

[0095] Furthermore, if the allowable delay time of an upstream packet is less than a predetermined value, the first transfer processing unit 111 changes the priority previously assigned to the upstream packet to a higher priority, so that upstream packets with an allowable delay time less than a predetermined value can be transmitted with even higher priority.

[0096] Furthermore, when the allowable delay time of an upstream packet is equal to or less than a predetermined value and there is space in a queue corresponding to a priority higher than the priority previously assigned to the upstream packet, the first transfer processing unit 111 changes the priority of the upstream packet to the even higher priority and stores it in the corresponding queue, thereby enabling the upstream packet with an allowable delay time equal to or less than a predetermined value to be transmitted preferably.

[0097] [Software implementation example] Some or all of the functions of the packet forwarding devices 1 and 1A may be realized by hardware such as an integrated circuit (IC chip), or may be realized by software.

[0098] In the latter case, the packet forwarding devices 1, 1A are realized, for example, by a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in FIG. 16. The computer C includes at least one processor C1 and at least one memory C2. The memory C2 stores a program P for operating the computer C as the packet forwarding devices 1, 1A. In the computer C, the processor C1 reads and executes the program P from the memory C2, thereby realizing each function of the packet forwarding devices 1, 1A.

[0099] The processor C1 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a micro processing unit (MPU), a floating point number processing unit (FPU), a physics processing unit (PPU), a microcontroller, or a combination thereof. The memory C2 may be, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof.

[0100] The computer C may further include a RAM for expanding the program P during execution and for temporarily storing various data. The computer C may also include a communication interface for transmitting and receiving data to and from other devices. The computer C may also include an input / output interface for connecting input / output devices such as a keyboard, mouse, display, and printer.

[0101] Furthermore, the program P can be recorded on a non-transitory tangible recording medium M that can be read by the computer C. Such a recording medium M can be, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The computer C can acquire the program P via such a recording medium M. The program P can also be transmitted via a transmission medium. Such a transmission medium can be, for example, a communication network or broadcast waves. The computer C can also acquire the program P via such a transmission medium.

[0102] [Appendix 1] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the above-described embodiments are also included in the technical scope of the present invention.

[0103] [Appendix 2] Some or all of the above-described embodiments can also be described as follows: However, the present invention is not limited to the following described aspects.

[0104] (Appendix 1) acquiring means for acquiring an upstream packet received from a terminal device; an allowable time determination means for determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; an order determination means for determining a transmission order of the upstream packets based on the allowable delay time; A packet forwarding device comprising:

[0105] According to the above configuration, the order determination means determines the order of transmission of upstream packets based on the allowable delay time, so that packets can be transferred in an appropriate order based on the time information of the packets.

[0106] (Appendix 2) The allowable time determination means Identifying a first delay time, which is a delay time from the terminal device to a base station, by referring to UL delay result information included in the header information; determining a second delay time, which is a delay time from the base station to the packet forwarding device, by referring to a UL transmission timestamp included in the header information and a reception time of the uplink packet by the packet forwarding device; determining an allowable delay time by comparing a sum of the first delay time and the second delay time with a target delay time; 2. A packet forwarding device according to claim 1.

[0107] According to the above configuration, the allowable time determination means determines the allowable delay time by comparing the sum of the first delay time and the second delay time with the target delay time, so that the allowable delay time can be easily determined.

[0108] (Appendix 3) The allowable time determination means The allowable delay time is a value obtained by subtracting the sum of the first delay time and the second delay time from the target delay time. 3. A packet forwarding device according to claim 2.

[0109] According to the above configuration, the allowable time determination means determines the allowable delay time as the target delay time minus the sum of the first delay time and the second delay time, so that the allowable delay time can be easily determined.

[0110] (Appendix 4) The order determination means an upstream packet that is an earlier packet in the transmission order and has a relatively large allowable delay time is swapped with an upstream packet that is a later packet in the transmission order and has a relatively small allowable delay time; 4. A packet forwarding device according to any one of appendixes 1 to 3.

[0111] According to the above configuration, it is possible to give priority to transmitting upstream packets with a relatively short allowable delay time.

[0112] (Appendix 5) a plurality of transmission queue means provided corresponding to the priority of packets and storing packets to be transmitted; The order determination means scheduling the rearranged uplink packets in the order in which they are rearranged, and storing the uplink packets in one of the plurality of transmission queue means; 5. A packet forwarding device according to claim 4.

[0113] According to the above configuration, it is possible to schedule upstream packets with a relatively small allowable delay time with priority.

[0114] (Appendix 6) The order determination means If the allowable delay time of the upstream packet is equal to or less than a predetermined value, the priority previously assigned to the upstream packet is changed to a higher priority. 6. A packet forwarding device according to claim 5.

[0115] According to the above configuration, it is possible to give higher priority to transmitting upstream packets whose allowable delay time is equal to or less than a predetermined value.

[0116] (Appendix 7) The order determination means storing the upstream packet in a transmission queue means corresponding to the changed priority; 7. A packet forwarding device according to claim 6.

[0117] According to the above configuration, it is possible to give higher priority to transmitting upstream packets whose allowable delay time is equal to or less than a predetermined value.

[0118] (Appendix 8) The order determination means When the allowable delay time of the upstream packet is equal to or less than a predetermined value, If there is a vacancy in the transmission queue means corresponding to a priority higher than the priority previously assigned to the upstream packet, changing the priority of the upstream packet to a higher priority and storing it in the corresponding transmission queue means; 8. A packet forwarding device according to any one of appendixes 5 to 7.

[0119] According to the above configuration, it is possible to suitably transmit upstream packets whose allowable delay time is equal to or less than a predetermined value.

[0120] (Appendix 9) The header information of the uplink packet is information added to a GTP extension header. 9. A packet forwarding device according to any one of appendices 1 to 8.

[0121] (Appendix 10) Acquires an uplink packet received from a terminal device, determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; determining a transmission order of the upstream packets based on the allowable delay time; Packet forwarding method.

[0122] According to the above configuration, the transmission order of upstream packets is determined based on the allowable delay time, so that packets can be transferred in an appropriate order based on the time information of the packets.

[0123] (Appendix 11) On the computer, A process of acquiring an uplink packet received from a terminal device; a process of determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; a process of determining a transmission order of the upstream packets based on the allowable delay time; A program that executes the following.

[0124] According to the above configuration, the transmission order of upstream packets is determined based on the allowable delay time, so that packets can be transferred in an appropriate order based on the time information of the packets.

[0125] (Appendix 12) at least one processor, the processor comprising: A process of acquiring an uplink packet received from a terminal device; a process of determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; a process of determining a transmission order of the upstream packets based on the allowable delay time; A packet forwarding device that performs the following:

[0126] The packet forwarding device may further include a memory that stores a program for causing the processor to execute the acquiring process, the process for determining the allowable delay time, and the process for determining the transmission order. The program may also be recorded on a computer-readable, non-transitory, tangible recording medium. [Explanation of symbols]

[0127] 1,1A Packet forwarding device (UPF / NW-TT) 2 DS-TT 3UE 4 (R)AN 5 AMF 6 SMF 7 PCF 8 TSN AF 9 UDM 10 NEF 11 Acquisition method 12 Means for determining allowable time 13 Order determining means 101 PFCP control section 102 Session Information Table 103 Target Delay Time Information Table 104 First receiving port 105 Second receiving port 106 Analysis Department 107 Lazy Evaluation Unit 108 Sorting section 109 Low Latency Receive Queue 110 Non-low latency receive queue 111 First transfer processing unit 112 Second transfer processing unit 113 First Transmission Unit 114 Second Transmission Unit 115 First Outbound Port 116 Second Outbound Port

Claims

1. A packet forwarding device, acquiring means for acquiring an upstream packet received from a terminal device; an allowable time determination means for determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; an order determination means for determining a transmission order of the upstream packets based on the allowable delay time; Equipped with The allowable time determination means Identifying a first delay time, which is a delay time from the terminal device to a base station, by referring to UL delay result information included in the header information; determining a second delay time, which is a delay time from the base station to the packet forwarding device, by referring to an UL transmission timestamp included in the header information and a reception time of the uplink packet by the packet forwarding device; determining an allowable delay time by comparing a sum of the first delay time and the second delay time with a target delay time; Packet forwarding equipment.

2. The allowable time determination means a value obtained by subtracting the sum of the first delay time and the second delay time from the target delay time is set as the allowable delay time; 2. The packet forwarding device according to claim 1.

3. The order determination means an upstream packet that is an earlier packet in the transmission order and has a relatively large allowable delay time is swapped with an upstream packet that is a later packet in the transmission order and has a relatively small allowable delay time; 3. The packet forwarding device according to claim 1.

4. a plurality of transmission queue means provided corresponding to the priority of packets and storing packets to be transmitted; The order determination means scheduling the rearranged uplink packets in the order in which they are rearranged, and storing the uplink packets in one of the plurality of transmission queue means; 4. The packet forwarding device according to claim 3.

5. The order determination means If the allowable delay time of the upstream packet is equal to or less than a predetermined value, the priority previously assigned to the upstream packet is changed to a higher priority.

5. The packet forwarding device according to claim 4.

6. The order determination means storing the upstream packet in a transmission queue means corresponding to the changed priority; 6. The packet forwarding device according to claim 5.

7. The order determination means When the allowable delay time of the upstream packet is equal to or less than a predetermined value, If there is a vacancy in the transmission queue means corresponding to a priority higher than the priority previously assigned to the upstream packet, changing the priority of the upstream packet to a higher priority and storing it in the corresponding transmission queue means; The packet forwarding device according to any one of claims 4 to 6.

8. A packet forwarding method for a packet forwarding device, comprising: Acquires an uplink packet received from a terminal device, determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; determining a transmission order of the upstream packets based on the allowable delay time; In determining the allowable delay time, Identifying a first delay time, which is a delay time from the terminal device to a base station, by referring to UL delay result information included in the header information; determining a second delay time, which is a delay time from the base station to the packet forwarding device, by referring to an UL transmission timestamp included in the header information and a reception time of the uplink packet by the packet forwarding device; determining an allowable delay time by comparing a sum of the first delay time and the second delay time with a target delay time; Packet forwarding method.

9. On the computer, A process of acquiring an uplink packet received from a terminal device; a process of determining an allowable delay time for the upstream packet by referring to time information included in header information of the upstream packet; a process of determining a transmission order of the upstream packets based on the allowable delay time; A program for a packet forwarding device that executes In the process of determining the allowable delay time, Identifying a first delay time, which is a delay time from the terminal device to a base station, by referring to UL delay result information included in the header information; determining a second delay time, which is a delay time from the base station to the packet forwarding device, by referring to an UL transmission timestamp included in the header information and a reception time of the uplink packet by the packet forwarding device; determining an allowable delay time by comparing a sum of the first delay time and the second delay time with a target delay time; program.

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