Control device, control method, and control program

Abstract

A controller (200) has a determination unit (222), a setting unit (223), and a resource request unit (224). The determination unit (222) determines, while avoiding congestion of priority packets on the basis of acquired information, the flow paths or the transmission timings thereof by which the opening time of a non-priority gate is lengthened. The setting unit (223) sets the paths or transmission timings of the priority packets, which have been determined by the determination unit (222), for a transmission terminal (10) or a transfer device (40).

Description

Technical Field

[0001] The present invention relates to a control device, a control method, and a control program.

Background Art

[0002] In a 5G environment, there is a case where packets with various QoS requirements are transferred within one network slice. Priority packets that require real-time performance, such as remote robot control, are transferred with priority over other non-priority packets that do not require real-time performance in order to guarantee communication delay and delay fluctuation value (jitter).

[0003] In order to guarantee the delay fluctuation value of the priority flow, there is a function called TAS (Time Aware Shaper) defined in IEEE802.1Qbv. A method has been proposed to reduce the queuing delay of priority packets by closing the gate for non-priority packets in advance at the time slot when priority packets that are periodically transmitted arrive at the transfer device (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the prior art, it is impossible to avoid congestion of priority packets and to ensure the opening time of non-priority gates. For example, when using TAS, each transfer device can synchronize the timing at which it closes the non-priority gate, but does not control the communication path or transmission timing of the flowing priority traffic. Therefore, there is a possibility that priority packets will arrive concentrated at a specific time and the priority packet queue will overflow, or that priority packets will arrive at various timings and the non-priority gate will remain blocked, greatly affecting non-priority packets.

[0006] In addition, users of network slices can reduce the usage fees of the slices by minimizing the network resources they use, but control is required to ensure the accommodation number of priority flows with fewer network resources.

[0007] The present invention has been made in view of the above, and an object thereof is to ensure the opening time of non-priority gates while avoiding congestion of priority packets.

Means for Solving the Problems

[0008] In order to solve the above-described problems and achieve the object, a control device according to the present invention includes an acquisition unit that acquires topology information indicating a connection form of a network and information on transfer delays of each transfer device that transfers priority packets and non-priority packets, and based on the topology information acquired by the acquisition unit and the information on transfer delays of each transfer device, a determination unit that determines a path or transmission timing of a flow of the priority packets, and a setting unit that sets the path or transmission timing of the flow determined by the determination unit for the transfer device or the transmission terminal.

Effects of the Invention

[0009] According to the present invention, it becomes possible to provide a controller that ensures the opening time of non-priority gates while avoiding congestion of priority packets.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by this embodiment. In the description of the drawings, the same parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0012] 〔1. Example of Configuration of Control System〕 First, the configuration of the control system 1 will be described with reference to FIG. 1. FIG. 1 is a diagram showing an example of the configuration of the control system 1 according to an embodiment. The system shown in FIG. 1 includes a transmission terminal 10, a controller (control device) 200, an orchestrator 30, and a transfer device 40. Note that the control system 1 may be implemented by a plurality of devices. Further, when the control system 1 is implemented by a plurality of devices, each component included in the control system 1 may be distributed among the plurality of devices in any manner.

[0013] First, the transmitting terminal 10 makes a request to the controller 200 to add a new flow. Also, the transmitting terminal 10 transmits the flow according to the transmission timing settings received from the controller 200. Next, the controller 200 receives the request to add a new flow from the transmitting terminal 10 and performs calculations. Here, if there is a shortage of resources as a result of the calculations, the controller 200 requests the orchestrator 30 to add resources. Also, the controller 200 sets flow control for the transmitting terminal 10 or the transfer device 40. Details of the controller 200 will be described later.

[0014] Next, the orchestrator 30 is an external device that manages slices. Also, the orchestrator 30 receives the resource addition request from the controller 200 and performs resource addition. And there are a plurality of transfer devices 40 on the network. The transfer devices 40 receive the transmission of the flow from the transmitting terminal 10 and perform the transfer of the flow.

[0015] [2. Configuration Example of Controller] Next, the configuration of the controller 200 will be described with reference to FIG. 2. FIG. 2 is a diagram showing an example of the configuration of the controller 200 according to the embodiment. As shown in FIG. 2, the controller 200 includes a communication unit 210, a control unit 220, and a storage unit 230. Note that each of these units may be held in a distributed manner by a plurality of devices. The processing of each of these units will be described below.

[0016] The communication unit 210 is realized by a NIC (Network Interface Card) or the like and enables communication between the control unit 220 and an external device via a telecommunication line such as a LAN (Local Area Network) or the Internet. For example, the communication unit 210 enables communication between the transfer device 40 or an external device and the control unit 220.

[0017] The storage unit 230 is implemented by a semiconductor memory device such as a RAM (Random Access Memory), a flash memory, or a storage device such as a hard disk or an optical disk. Here, the storage unit 230 includes a NW topology storage unit 231 and an accommodated flow storage unit 232.

[0018] The NW topology storage unit 231 stores topology information which is the configuration information of the network, the delay time of each transfer device 40, the maximum flow rate, and information on the minimum opening time of non-priority gates. Further, the accommodated flow storage unit 232 stores information on the target delay time, the source node, and the destination node of the already accommodated flow. Note that the above is an example, and what the NW topology storage unit 231 and the accommodated flow storage unit 232 store is not limited to what is listed here.

[0019] Then, the control unit 220 is implemented using a CPU (Central Processing Unit), an NP (Network Processor), an FPGA (Field Programmable Gate Array), etc., and executes a processing program stored in the memory. Thereby, the control unit 220 functions as an acquisition unit 221, a determination unit 222, a setting unit 223, a resource request unit 224, and a topology update reception unit 225. Note that these functional units may be implemented by different hardware respectively. Also, the control unit 220 may include other functional units.

[0020] The acquisition unit 221 acquires topology information indicating the connection form of the network, and information on the transfer delay of each transfer device that transfers priority packets and non-priority packets. Further, the acquisition unit 221 further acquires information on the minimum opening time of the non-priority gate in each transfer device. For example, the acquisition unit 221 acquires topology information indicating the connection form of the network, the transfer delay of the transfer device 40, the maximum flow rate, and the minimum opening time of the non-priority gate from the NW topology storage unit 231. Also, the acquisition unit 221 acquires the target delay time of the accommodated flow, and information on the source node and the destination node from the accommodated flow storage unit 232. Further, when a new flow addition request is received from the transmission terminal 10, the acquisition unit 221 acquires information on the source node, the destination node, and the target delay time of the new flow from the transmission terminal 10.

[0021] The determination unit 222 determines the path or transmission timing of the flow of priority packets based on the topology information acquired by the acquisition unit 221 and the information on the transfer delay of each transfer device 40. Further, the determination unit 222 determines, based on the topology information acquired by the acquisition unit 221, the transfer delay of each transfer device 40, and the information on the minimum opening time of the non-priority gate, that the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or greater than the minimum opening time set for the non-priority gate, and determines the path or transmission timing of the flow.

[0022] For example, the determination unit 222 determines the path or transmission timing of the flow based on the information stored in the storage unit 230 and the information notified from the transmission terminal 10. Here, the transmission timing refers to the timing at which the transfer device 40 transfers the flow. Also, the transmission timing is not limited to the above, and may be the timing at which the transmission terminal 10 transmits the flow.

[0023] Regarding the specific process, for example, the determination unit 222 determines the path or transmission timing of a flow based on the topology information indicating the connection form of the network held by the NW topology storage unit 231, the information on the transfer delay of the transfer device 40, the minimum opening time of the non-priority gate, the source node of the flow notified from the transmission terminal 10, the destination node, and the information on the target delay time, such that the delay time until the flow is transferred from the source node to the destination node is within the target time of the flow and no more than the capacity of the same transfer device 40 is transferred during the same period.

[0024] At this time, the determination unit 222 may perform the calculation of the path and transmission timing by utilizing the optimal solution that is the calculation result by the linear programming problem solver. For example, the determination unit 222 formulates a linear programming problem with the following objective function, constraints, and variables based on the topology information, the information on the transfer delay of the transfer device 40, the minimum opening time of the non-priority gate, the source node of the flow notified from the transmission terminal 10, the destination node, and the information on the target delay time, and delivers it to the linear programming problem solver and accepts the return of the variable results.

[0025] The objective function of the linear programming problem is set to minimize, for example, the closing time of the non-priority gate at the node as shown in the following mathematical formula (1), minimize the packets that do not satisfy the QoS, or minimize the closing time of the non-priority gate at the node in all time slots.

[0026]

Equation

[0027] In addition, the constraint conditions are the topology, transfer capacity, information on the traffic volume, route, and target delay of each flow, and the minimum opening time of non-priority gates at each node. Also, the variables are the route of the flow and the transmission timing, and real number solutions are obtained. In this way, the determination unit 222 determines the route of the flow or the transmission timing that ensures the opening time of the non-priority gate while avoiding congestion of the priority packets. To explain the specific process, for example, when the network is in the initial state, the determination unit 222 performs calculations with all flows as variables. On the other hand, when the network is not in the initial state, the determination unit 222 calculates with the existing flows as constants and the additional flows as variables. Through these calculations, the determination unit 222 determines the route of the flow or the transmission timing that ensures the opening time of the non-priority gate while avoiding congestion of the priority packets.

[0028] The setting unit 223 sets the route of the flow or the transmission timing determined by the determination unit 222 for the transfer device 40 or the transmission terminal 10. Also, the setting unit 223 sets the timing for transferring the flow of the transfer device 40 as the transmission timing determined by the determination unit 222. Further, the setting unit 223 sets the timing for transmitting the flow of the transmission terminal 10 as the transmission timing determined by the determination unit 222. Specific examples will be described later with reference to FIGS. 4 and 5.

[0029] When, as a result of the calculation by the determination unit, the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is not less than the minimum opening time set for the non-priority gate, and the route of the flow or the transmission timing cannot be determined, the resource request unit 224 requests an external device to add resources. Here, examples of the external device to which the resource request unit 224 requests resource addition include the orchestrator 30 and the like.

[0030] Also, for example, the resource request unit 224 requests an external device to add resources necessary for determining the path and transmission timing of a flow such that the delay time until the flow is transmitted from the source node to the destination node is within a target delay time set in advance for each flow, and the time during which the non-priority gate is open is equal to or longer than the minimum open time set for the non-priority gate.

[0031] The topology update reception unit 225 receives an update of topology information indicating the connection form of the network and stores it in the NW topology storage unit 231. For example, when there is a change in the connection form of the network, the topology update reception unit 225 receives a notification of the topology update and stores the new topology information in the NW topology storage unit 231.

[0032] [3. Transfer Procedure for Additional Flows] Next, with reference to FIG. 3, the procedure until the transfer of the flow by the control system 1 will be described. FIG. 3 is a diagram showing an example of the procedure until the transfer of the flow by the control system 1 according to the embodiment. As shown in FIG. 3, the control system of the present embodiment includes a transmission terminal 10, a controller 200, an orchestrator 30, and a transfer device 40.

[0033] First, the transmission terminal 10 makes a request to add a flow to the controller 200 (1). At this time, the transmission terminal 10 notifies the controller 200 of information on the source node, destination node, and target delay of the flow for which the addition is requested. Next, the controller 200 determines the path or transmission timing of the flow based on the information on the source node, destination node, and target delay of the flow notified from the transmission terminal 10, the topology information it holds, and the transfer delay information of the transfer device 40 (2). Here, if the controller 200 cannot determine the path or transmission timing of the flow, assuming that there is a shortage of resources, the controller 200 requests the orchestrator 30 to add a minimum amount of resources (3).

[0034] Next, the orchestrator 30 that has received the minimum resource addition request from the controller 200 performs a resource addition process (4). After that, the orchestrator 30 notifies the controller 200 that the resource addition process has been successfully performed (5).

[0035] Next, the controller 200 sets the determined flow path or transmission timing for the transfer device 40 (6). As a result, in the transfer device 40, the flow path or transmission timing is set (7). Next, the transfer device 40 notifies the controller 200 that the flow path or transmission timing has been successfully set (8). Next, the controller 200 sets the flow transmission timing for the transmission terminal 10 (9). Then, the transmission terminal 10 starts transmitting the flow (10).

[0036] [4. Flow Control by Path Setting] Next, with reference to FIG. 4, the efficiency improvement of flow transfer by path setting will be described. FIG. 4 is a diagram showing the efficiency improvement of flow transfer by the controller 200. In the following example, 12 is set as the target delay time for each of Flow 1 and Flow 2. FIG. 4(1) is an example of the transfer of an uncontrolled flow, and shows Flow 1 and Flow 2.

[0037] Here, since the delay time of Flow 1 is 10 and the delay time of Flow 2 is 12, both flows are transferred within the target delay time. However, since the paths of Flow 1 and Flow 2 partially overlap, traffic collisions may occur. At this time, if the total amount of the collided traffic exceeds the maximum flow rate of the transfer device 40, congestion will occur.

[0038] On the other hand, FIG. 4(2) is an example of the transfer of a flow controlled by path setting, and shows Flow 1 and Flow 2. Here, the controller 200 performs flow control, performs path setting that can transfer Flow 1 and Flow 2 within the target delay time, and eliminates the overlap between the path of Flow 1 and the path of Flow 2.

[0039] Specifically, first, the controller 200 calculates the path of the flow, the transmission timing, which ensures the minimum opening time of each non-priority gate and minimizes the blocking time of the non-priority gate while avoiding congestion. Then, by setting the path obtained by this calculation for the transfer device 40, the controller 200 transfers Flow 1 and Flow 2 from the source node to the destination node within their respective target delay times, and also avoids congestion caused by the total amount of collision traffic exceeding the maximum flow rate of the transfer device 40. Further, thereby, the controller 200 secures the minimum opening time of the non-priority gate and maximizes the transfer efficiency of the flow by reducing the load on the transfer device 40.

[0040] 〔5. Flow control by transmission timing setting〕 Next, with reference to FIG. 5, the efficiency improvement of flow transfer by setting the transmission timing will be described. FIG. 5 is a diagram showing the efficiency improvement of flow transfer by the controller 200. In the following example, 12 is set as the target delay time for each of Flow 1, Flow 2, and Flow 3.

[0041] FIG. 5(1) is an example of the transfer of an uncontrolled flow, showing Flow 1, Flow 2, and Flow 3. Here, since the delay time of Flow 1 is 12, the delay time of Flow 2 is 10, and the delay time of Flow 3 is 12, all are transferred within the target delay time of the flow. However, because the transmission timing is not appropriate, the transfer device 40 is loaded, and the non-priority gate is blocked in a plurality of time slots. In this way, a problem occurs in that the congestion of non-priority packets increases due to the increase in the blocking time of the non-priority gate.

[0042] On the other hand, FIG. 5(2) shows an example of the transfer of a flow controlled by setting the transmission timing, and shows Flow 1, Flow 2, and Flow 3. Here, the controller 200 performs flow control by setting the transmission timing of the flow for the transmission terminal 10 or the transfer device 40, and sets the transmission timing for transferring Flow 1, Flow 2, and Flow 3 within the target delay time, thereby reducing the blocking time of the non-priority gate.

[0043] Specifically, first, the controller 200 calculates the path and transmission timing of the flow that ensures the minimum opening time of each non-priority gate and minimizes the blocking time of the non-priority gate while avoiding congestion. Then, the controller 200 sets the transmission timing obtained by this calculation for the transmission terminal 10 or the transfer device 40. Thereby, the controller 200 transfers Flow 1, Flow 2, and Flow 3 from the source node to the destination node within their respective target delay times, and by reducing the load on the transfer device 40, ensures the minimum opening time of the non-priority gate and maximizes the transfer efficiency of the flow.

[0044] 〔6. Flowchart〕 Next, with reference to FIG. 6, the flow of flow control by the controller 200 will be described. FIG. 6 is a flowchart showing an example of the flow of flow control according to the present embodiment.

[0045] First, the determination unit 222 determines whether the network is in the initial state (step S101). At this time, if the network is in the initial state (step S101 “Yes”), the determination unit 222 performs an optimization calculation with all flows as variables (step S102). Specifically, the determination unit 222 performs an optimization calculation to minimize the blocking time of the non-priority gate while ensuring the minimum opening time of each non-priority gate and avoiding congestion, with the paths and transmission timings of all flows as variables.

[0046] Also, when the network is not in the initial state (step S101 “No”), optimization calculation is performed with the existing flow as a constant and the additional flow as a variable (step S103). Specifically, the determination unit 222 performs optimization calculation to minimize the blocking time of the non-priority gates while ensuring the minimum opening time and avoiding congestion of the non-priority gates, with the route and transmission timing of the existing flow as constants and the route and transmission timing of the additional flow as variables.

[0047] Next, it is determined whether the optimal variable satisfies the following mathematical formula (2) as a result of the calculation (step S104). Here, when the optimal variable does not satisfy the following mathematical formula (2) (step S104 “No”), it means that resources are insufficient. On the other hand, when the optimal variable satisfies the following mathematical formula (2) (step S104 “Yes”), it means that resources are not insufficient.

[0048] Here, when the optimal variable does not satisfy the following mathematical formula (2) (step S104 “No”), the resource request unit 224 requests an increase in the bandwidth to the transfer device 40 that exceeds the maximum flow rate with the optimal variable (step S105). And when the optimal variable satisfies the following mathematical formula (2) (step S104 “Yes”), or after the process of step S105 is completed, the setting unit 223 sets the route or transmission timing with the optimal variable for the transfer device 40, or the transmission timing with the optimal variable for the transmission terminal 10, and transfers the flow (step S106).

[0049]

Equation

[0050] 〔7. Effect〕 As described above, the controller 200 according to the embodiment includes an acquisition unit 221, a determination unit 222, and a setting unit 223. The acquisition unit 221 acquires topology information indicating the connection form of the network and information on the transfer delay of each transfer device 40 that transfers priority packets and non-priority packets. The determination unit 222 determines the path or transmission timing of the flow of priority packets based on the topology information acquired by the acquisition unit 221 and the information on the transfer delay of each transfer device 40. The setting unit 223 sets the path or transmission timing of the flow determined by the determination unit 222 for the transfer device 40 or the transmission terminal 10.

[0051] Thereby, the controller 200 according to the embodiment can maximize the transfer efficiency of the priority flow and avoid the congestion of the priority flow based on the acquired information. That is, the controller 200 can maximize the transfer efficiency of the flow and prevent the collision of priority packets while minimizing the impact on non-priority packets by setting the path or transmission timing of the flow for the transmission terminal 10 or the transfer device 40 using the collected information.

[0052] Also, thereby, the controller 200 according to the embodiment can ensure the minimum opening time of the non-priority gate. Also, thereby, the controller 200 according to the embodiment can minimize the resources used and reduce the slice usage fees of the operators using the slices.

[0053] In the controller 200 according to the embodiment, the setting unit 223 controls the flow transfer by setting the timing for transferring the flow to the transfer device 40. Thereby, the controller 200 according to the embodiment can perform flow control by the transfer device 40 and reduce the blocking time of the non-priority gate.

[0054] In the controller 200 according to the embodiment, the setting unit 223 controls the flow transfer by setting the timing for transmitting the flow to the transmission terminal 10. Thereby, the controller 200 according to the embodiment can perform flow control by the transmission terminal 10 and reduce the blocking time of the non-priority gate.

[0055] In the controller 200 according to the embodiment, the acquisition unit 221 further acquires information on the minimum opening time of the non-priority gate in the transfer device 40, and the determination unit 222 is based on the topology information acquired by the acquisition unit 221, the transfer delay of the transfer device 40, and the information on the minimum opening time of the non-priority gate. Determine the path or transmission timing of the flow such that the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or greater than the minimum opening time set for the non-priority gate. As a result of the calculation by the determination unit 222, when the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or greater than the minimum opening time set for the non-priority gate, and the path or transmission timing of the flow cannot be determined, it further has a resource request unit 224 that requests an external device to add resources.

[0056] Thereby, the controller 200 according to the embodiment can eliminate the resource shortage by requesting resources from the orchestrator 30. Also, thereby, the controller 200 according to the embodiment can avoid congestion of priority packets due to resource shortage.

[0057] In the controller 200 according to the embodiment, the resource request unit 224 requests the orchestrator 30 to add resources necessary for determining the path or transmission timing of the flow such that the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or greater than the minimum opening time set for the non-priority gate.

[0058] Accordingly, when the resources are insufficient, the controller 200 according to the embodiment can request the minimum resources from the orchestrator 30 to eliminate the resource shortage. Further, accordingly, the controller 200 according to the embodiment can minimize the increase in the usage fee of the slice for the operator using the slice.

[0059] 〔8. Program〕 It is also possible to create a program that describes the processing executed by the controller 200 described in the above embodiment in a computer-executable language. In this case, by executing the program on the computer, the same effects as the above embodiment can be obtained. Further, such a program may be recorded on a computer-readable recording medium, and the same processing as the above embodiment may be realized by causing the computer to read and execute the program recorded on this recording medium.

[0060] FIG. 7 is a diagram showing an example of a computer that executes a program. As shown in FIG. 7, the computer 1000 includes, for example, a memory 1010, a CPU 1020, a hard disk drive interface 1030, a disk drive interface 1040, a serial port interface 1050, a video adapter 1060, and a network interface 1070. These components are connected by a bus 1080.

[0061] Memory 1010 includes a ROM (Read Only Memory) 1011 and a RAM 1012. The ROM 1011 stores a boot program such as a BIOS (Basic Input Output System). The hard disk drive interface 1030 is connected to the hard disk drive 1090. The disk drive interface 1040 is connected to the disk drive 1041. A removable storage medium such as a magnetic disk or an optical disk is inserted into the disk drive 1041. For example, a mouse 1110 and a keyboard 1120 are connected to the serial port interface 1050. For example, a display 1130 is connected to the video adapter 1060.

[0062] Here, as shown in FIG. 7, the hard disk drive 1090 stores, for example, an OS 1091, an application program 1092, program modules 1093, and program data 1094. Each table described in the above embodiment is stored, for example, in the hard disk drive 1090 or the memory 1010.

[0063] Also, the control program is stored in the hard disk drive 1090 as a program module in which instructions executed by the computer 1000 are described. Specifically, a program module 1093 in which each process executed by the controller 200 described in the above embodiment is described is stored in the hard disk drive 1090.

[0064] Also, data used for information processing by the control program is stored, as program data, in the hard disk drive 1090, for example. Then, the CPU 1020 reads out the program module 1093 and the program data 1094 stored in the hard disk drive 1090 into the RAM 1012 as needed, and executes each of the above-described procedures.

[0065] Note that the program modules 1093 and program data 1094 related to the control program are not limited to being stored in the hard disk drive 1090. For example, they may be stored in a removable storage medium and read by the CPU 1020 via a disk drive 1041 or the like. Alternatively, the program modules 1093 and program data 1094 related to the control program may be stored in another computer connected via a network such as a LAN (Local Area Network) or WAN (Wide Area Network), and read by the CPU 1020 via the network interface 1070.

Explanation of Signs

[0066] 1 Control System 10 Transmission Terminal 200 Controller (Control Device) 210 Communication Unit 220 Control Unit 221 Acquisition Unit 222 Decision Unit 223 Setting Unit 224 Resource Request Unit 225 Topology Update Reception Unit 230 Storage Unit 231 NW Topology Storage Unit 232 Accommodation Flow Storage Unit 30 Orchestrator 40 Transfer Device

Claims

1. An acquisition unit that acquires topology information indicating the connection form of a network and information on the transfer delay of each transfer device that transfers priority packets and non-priority packets; A determination unit that determines the path or transmission timing of the flow of the priority packets based on the topology information acquired by the acquisition unit and the information on the transfer delay of each transfer device; A setting unit that sets the path or transmission timing of the flow determined by the determination unit for the transfer device or the transmission terminal, and has: The acquisition unit further acquires information on the minimum opening time of non-priority gates in each transfer device. Based on the topology information acquired by the acquisition unit, the transfer delay of each transfer device, and the information on the minimum opening time of non-priority gates, the determination unit determines that the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or greater than the minimum opening time set for the non-priority gate. Determine the path or transmission timing of the flow. If, as a result of the calculation by the determination unit, the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or greater than the minimum opening time set for the non-priority gate, and the path or transmission timing of the flow cannot be determined, it further has a resource request unit that requests an external device to add resources. A control device characterized by the above.

2. The control device according to claim 1, wherein the setting unit sets, as the transmission timing determined by the determination unit, the timing for transferring the flow of the transfer device.

3. The control device according to claim 1, wherein the setting unit sets, as the transmission timing determined by the determination unit, the timing for transmitting the flow of the transmission terminal.

4. The resource request unit requests the external device to add resources necessary for determining the path or transmission timing of the flow such that the delay time until the flow is transmitted from the source node to the destination node is within a target delay time set in advance for each flow, and the time during which the non-priority gate is open is equal to or longer than a minimum open time set for the non-priority gate. The control device according to claim 1, characterized in that.

5. A control method executed by a control device, comprising: an acquisition step of acquiring topology information indicating a connection form of a network and information on transfer delays of each transfer device that transfers priority packets and non-priority packets; a determination step of determining a path or transmission timing of a flow of the priority packet based on the topology information acquired in the acquisition step and the information on transfer delays of each transfer device; a setting step of setting the path or transmission timing of the flow determined in the determination step for the transfer device or the transmission terminal, wherein the acquisition step further acquires information on a minimum open time of a non-priority gate in each transfer device; the determination step is based on the topology information acquired in the acquisition step, the transfer delay of each transfer device, and the information on the minimum open time of the non-priority gate, and determines the path or transmission timing of the flow such that the delay time until the flow is transmitted from the source node to the destination node is within a target delay time set in advance for each flow, and the time during which the non-priority gate is open is equal to or longer than a minimum open time set for the non-priority gate; when the path or transmission timing of the flow cannot be determined such that the delay time until the flow is transmitted from the source node to the destination node is within a target delay time set in advance for each flow, and the time during which the non-priority gate is open is equal to or longer than a minimum open time set for the non-priority gate, based on the result calculated in the determination step, the method further includes a resource request step of requesting the external device to add resources. A control method characterized by the above.

6. an acquisition step of acquiring topology information indicating a connection form of a network and information on transfer delays of each transfer device that transfers priority packets and non-priority packets; A determination step of determining a path or transmission timing of a flow of the priority packet based on the topology information acquired in the acquisition step and information on the transmission delay of each transfer device, A setting step of setting the path or transmission timing of the flow determined in the determination step for the transfer device or the transmission terminal, which is a control program that causes a computer to execute, The acquisition step further acquires information on the minimum opening time of non-priority gates in each transfer device, The determination step is based on the topology information acquired in the acquisition step, the transfer delay of each transfer device, and information on the minimum opening time of non-priority gates, and the delay time until the flow is transmitted from the source node to the destination node is within a target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or longer than the minimum opening time set for the non-priority gate. Determine the path or transmission timing of the flow, If, as a result of the determination step, the delay time until the flow is transmitted from the source node to the destination node is within the target delay time set in advance for each flow, and the time when the non-priority gate is open is equal to or longer than the minimum opening time set for the non-priority gate, and the path or transmission timing of the flow cannot be determined, a resource request step of requesting an external device to add resources is further executed by the computer, Control program.

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