Control device, communication device, transmission device, and control method

Abstract

Provided is a control device for performing control on a communication system including a communication device, a first transmission device connected to the communication device by a logical line, and a second transmission device connected to the first transmission device by a transmission path, the control device comprising: a management unit for managing mapping information between the logical line and the transmission path, the band of the logical line, and the band of the transmission path; a band calculation unit for determining, on the basis of traffic in the logical line and the information managed by the management unit, whether a band change for the logical line or the transmission path is necessary; and a control unit for implementing a band change for the logical line or the transmission path when the band change is necessary.

Description

Control device, communication device, transmission device, and control method

[0001] The present invention relates to a technology for changing a network bandwidth in accordance with traffic.

[0002] There is a conventional technology that provides a communication path between L3 / L2 switches via an optical network (optical NW). Note that "L3 / L2 switch" means "L3 switch or L2 switch."

[0003] The communication path between the L3 / L2 switches is composed of a transmission path obtained by dividing the wavelength path between the transmission devices at both ends of the optical network, and a logical line in the physical link between the L3 / L2 switch and the transmission device.

[0004] Recommendation G.709Recommendation G.7044 / Y.1347https: / / www.oiforum.com / wp-content / uploads / OIF-FLEXE-02.2.pdf

[0005] The bandwidth of a communication path needs to be changed depending on the traffic on the communication path. However, in conventional technology, the control of the L3 / L2 switch and the control of the transmission device are independent, which means that the bandwidth cannot be changed quickly to accommodate traffic that dynamically changes from moment to moment.

[0006] The present invention has been made in view of the above points, and has as its object to provide a technique that enables a rapid bandwidth change in a network in response to dynamically changing traffic.

[0007] According to the disclosed technology, there is provided a control device that controls a communication system including a communication device, a first transmission device connected to the communication device by a logical line, and a second transmission device connected to the first transmission device by a transmission path, the control device comprising: a management unit that manages mapping information between the logical line and the transmission path, the bandwidth of the logical line, and the bandwidth of the transmission path; a bandwidth calculation unit that determines whether a bandwidth change is necessary for the logical line or the transmission path based on traffic on the logical line and information managed by the management unit; and a control unit that implements the bandwidth change for the logical line or the transmission path when the bandwidth change is necessary.

[0008] The disclosed technology provides a technology that enables rapid bandwidth changes in a network in response to dynamically changing traffic.

[0009] FIG. 1 is a diagram illustrating an example of a communication system that provides a communication path between L3 / L2 switches via an optical network. FIG. 2 is a diagram illustrating an example of a configuration of a communication system according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of information of an L3 / L2 switch. FIG. 4 is a diagram illustrating an example of information of a transmission device. FIG. 5 is a diagram illustrating an example of information of a transmission path. FIG. 6 is a diagram illustrating an example of a configuration of a controller 40 according to a first embodiment. FIG. 7 is a diagram illustrating an example of an operation of the communication system according to the first embodiment. FIG. 8 is a diagram illustrating an example of a configuration of an L3 / L2 switch 10 according to a second embodiment. FIG. 9 is a diagram illustrating an example of a configuration of a transmission device 20 according to the second embodiment. FIG. 10 is a diagram illustrating an example of an operation of the communication system according to the second embodiment. FIG. 11 is a diagram illustrating an example of a hardware configuration of a device.

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] In the following, first, the conventional technology will be described in more detail, and then the technology according to the present embodiment will be described.

[0012] (Regarding Prior Art) Figure 1 shows an example of a communication system that provides a communication path between L3 / L2 switches via an optical network. As shown in Figure 1, this communication system includes transmission devices 20A and 20B between an L3 / L2 switch 10A and an L3 / L2 switch 10B, and two communication paths between the L3 / L2 switches are established. An NMS (Network Management System) 30 is also provided, and the NMS 30 issues a bandwidth change instruction to each transmission device. When referring to the reference symbols 10A, 10B, 20A, 20B, etc. without distinguishing between the A side and the B side, the reference symbols 10 and 20 are used.

[0013] The L3 / L2 switch 10A and the transmission device 20A are connected by a physical link, the transmission device 20A and the transmission device 20B are connected by an optical network (more specifically, a wavelength path), and the transmission device 20B and the L3 / L2 switch 10B are connected by a physical link.

[0014] When providing a communication path between L3 / L2 switches via an optical network, the wavelength path in the optical network can be divided into multiple transmission paths according to the required bandwidth. An example of the transmission path is an optical-channel data unit (ODU) path using an optical transport network (OTN) (Non-Patent Document 1).

[0015] 1, when the bandwidth of a communication path is changed due to a change in traffic, a bandwidth change request is sent to the NMS 30, and the NMS 30 issues a bandwidth change instruction to each transmission device, thereby enabling the bandwidth change. Here, as a means for changing the bandwidth in the OTN without interrupting traffic, for example, there is Hitless Adjustment ODUflex (Non-Patent Document 2).

[0016] In order to efficiently use the physical link between the L3 / L2 switch 10 and the transmission device 20, logical multiplexing of multiple lines may be performed to configure multiple communication paths between the L3 / L2 switches. Methods of logical multiplexing include VLAN and FlexE (Non-Patent Document 3).

[0017] In such a case, it is necessary to restrict the traffic of the L3 / L2 switch 10 so that it matches the bandwidth of the transmission path set between the transmission devices 20. However, in the case of VLAN, traffic can be set to an appropriate size by shaping / policing, and in the case of FlexE, by calendar configuration.

[0018] In the FlexE calendar configuration, 100GE is divided into slots of 5G (or 25G) units, and it is possible to determine which L3 / L2 inter-switch communication path each slot is assigned to. By changing this calendar configuration, it is possible to change the bandwidth assigned to the L3 / L2 inter-switch communication path.

[0019] (Regarding the Issues) In the prior art, the control of the L3 / L2 switch 10 and the control of the transmission device 20 were independent, which meant that it was not possible to quickly change the bandwidth in response to traffic that dynamically fluctuates from moment to moment.

[0020] (Outline of the embodiment) In this embodiment, in order to solve the above problem, the control of the L3 / L2 switch and the control of the transmission device are linked to realize rapid bandwidth changes in response to dynamically changing traffic.

[0021] (System Configuration Example) Fig. 2 shows an example of the configuration of a communication system in this embodiment. The overall configuration of the communication system in this embodiment is basically the same as the overall configuration of the communication system shown in Fig. 1, but as shown in Fig. 2, this embodiment is provided with a controller 40. Fig. 2 also shows the IDs of each device and the numbers of the logical lines. These IDs / numbers correspond to those shown in Figs. 3 to 5, which will be described later.

[0022] The controller 40 may be called a control device. A device that uses a logical line may be called a communication device. The L3 / L2 switch 10 is an example of a communication device.

[0023] The controller 40 manages (stores) information on L3 / L2 switches, information on transmission devices, and information on transmission paths.

[0024] An example of L3 / L2 switch information is shown in Fig. 3. As shown in Fig. 3, the controller 40 stores, as L3 / L2 switch information, the number of the logical line set in each device, the bandwidth set in that logical line (shaping / policing in VLAN, calendar configuration in FlexE), and the traffic (traffic volume) flowing through that logical line. The traffic may be the current traffic or may be stored as historical information.

[0025] An example of information about a transmission device is shown in Fig. 4. As shown in Fig. 4, as information about a transmission device, the controller 40 manages the ID of a transmission path set in each device and the number of a logical line (on the device itself and on the remote device side) mapped to the transmission path.

[0026] Regarding "own device side, remote device side," for example, if transmission device 20A (device ID = γ) is the own device, transmission path #A is set in transmission device 20A (device ID = γ), and the logical line on the own device side mapped to transmission path #A is logical line #1, and the logical line on the remote device side mapped to transmission path #A is logical line #3.

[0027] An example of transmission path information is shown in Fig. 5. As shown in Fig. 5, the controller 40 manages the transmission path information including the transmission path ID, the device IDs of both endpoints, the relay route, and the bandwidth.

[0028] The controller 40 periodically acquires traffic information for each logical line from the L3 / L2 switches 10A and 10B, calculates the required bandwidth for transmitting the traffic through the communication path, and, if it is necessary to change the bandwidth of the currently set logical line or transmission path based on the required bandwidth, changes the bandwidth of the transmission path or logical line.

[0029] As shown in Figures 3 to 5, mapping information between transmission paths and logical lines is managed, so control of the L3 / L2 switches and control of the transmission devices can be linked, enabling bandwidth changes to be made quickly in response to dynamically changing traffic.

[0030] In addition to traffic information, a schedule or the like may be used as a trigger for changing the bandwidth. For example, the controller 40 can predict traffic through trend analysis and change the bandwidth in accordance with the predicted traffic.

[0031] The controller 40 (control device) may be realized as a single physical device, or may be realized as a plurality of physical devices that cooperate with each other.

[0032] Furthermore, instead of the controller 40 determining and instructing a band change, the L3 / L2 switch 10 and the transmission device 20 may autonomously determine and instruct the band change.

[0033] Below, the configuration and operation when the controller 40 determines and instructs a bandwidth change will be described as Example 1, and the configuration and operation when the L3 / L2 switch 10 and the transmission device 20 autonomously determine and instruct will be described as Example 2.

[0034] (First embodiment) <Device configuration example> Fig. 6 shows a configuration example of the controller 40 in the first embodiment. As shown in Fig. 6, the controller 40 in the first embodiment includes a bandwidth calculation unit 41, an L3 / L2 switch management unit 42, a transmission device management unit 43, a transmission path management unit 44, a traffic acquisition unit 45, an L3 / L2 switch control unit 46, and a transmission device control unit 47. The functions of each unit are as follows:

[0035] The bandwidth calculation unit 41 calculates the bandwidth required to transmit the traffic using the traffic data acquired by the traffic acquisition unit 45. When the traffic flows through a logical line and a transmission path mapped to the logical line, the "required bandwidth" is the bandwidth required for the logical line and the transmission path.

[0036] For example, a prediction algorithm using historical information can be used to calculate the bandwidth. The bandwidth calculation unit 41 also determines whether or not it is necessary to change the bandwidth of the logical line / transmission path. The bandwidth calculation unit 41 also determines whether or not it is possible to change the bandwidth of the logical line / transmission path based on the available bandwidth of the transmission path (physical link, wavelength path, etc.). In this specification, " / " means "or."

[0037] The L3 / L2 switch management unit 42 manages (stores) the logical lines set in each L3 / L2 switch, the bandwidth set in the logical lines, and the traffic flowing through them. Fig. 3 shows an example of information managed by the L3 / L2 switch management unit 42. An entry is added when an L3 / L2 switch is added or removed, or when a logical line is set or removed.

[0038] The transmission device management unit 43 manages the transmission paths set in each transmission device and the logical lines (local device side, remote device side) mapped to the transmission paths. Fig. 4 shows an example of information managed by the transmission device management unit 43. An entry is added when a transmission device is added / deleted or a transmission path is set / deleted.

[0039] The transmission path management unit 44 manages the transmission path ID, the device IDs of both endpoints, the relay route, and the bandwidth. Fig. 5 shows an example of information managed by the transmission path management unit 44. An entry is added when a transmission path is set up or deleted. The transmission path management unit 44 also includes a route calculation function for the transmission path.

[0040] The L3 / L2 switch management unit 42, the transmission device management unit 43, and the transmission path management unit 44 may be collectively referred to as the "management unit."

[0041] The traffic acquisition unit 45 acquires traffic information of each logical line from the L3 / L2 switch 10. The traffic acquisition unit 45 acquires the traffic information, for example, periodically. Alternatively, a traffic threshold may be set in the L3 / L2 switch 10, and the L3 / L2 switch 10 may notify the traffic acquisition unit 45 of the traffic information when the traffic exceeds the threshold.

[0042] The L3 / L2 switch control unit 46 controls the L3 / L2 switch 10. This control includes setting up / deleting logical lines to the L3 / L2 switch 10, changing the bandwidth of already-set logical lines, etc. The transmission device control unit 47 controls the transmission devices. This control includes setting up / deleting transmission paths to the transmission devices, changing the bandwidth of already-set transmission paths, etc. The L3 / L2 switch control unit 46 and the transmission device control unit 47 may be collectively referred to as the "control unit."

[0043] In the above example, the controller 40 manages the transmission paths for the transmission device 20, but it may also manage wavelength paths in addition to the transmission paths.

[0044] <Operation Example> An operation example of the communication system in the first embodiment will be described with reference to Fig. 7. In S101, the traffic acquisition unit 45 of the controller 40 acquires traffic information of each logical line from the L3 / L2 switches 10A and 10B.

[0045] In S102, the bandwidth calculation unit 41 of the controller 40 calculates the required bandwidth for the communication path (logical line and transmission path) through which the traffic flows, based on the traffic information acquired in S101. For example, future traffic is predicted for a predetermined period, and the predicted traffic (or the predicted traffic + α) is set as the required bandwidth.

[0046] In S103, the bandwidth calculation unit 41 compares the current bandwidth with the required bandwidth for each logical line and each transmission path to determine whether a bandwidth change is necessary, and also determines whether the bandwidth of the logical line / transmission path can be changed based on the available bandwidth in the transmission path. Here, it is assumed that the bandwidth of the logical line / transmission path can be changed.

[0047] If a bandwidth change is necessary (YES in S103), the transmission device control unit 47 instructs the transmission devices 20A and 20B to change the bandwidth of the transmission path. The transmission devices 20A and 20B that receive the instruction change the bandwidth of the transmission path. As a method for changing the bandwidth of the transmission path, for example, Hitless Adjustment ODUflex (Non-Patent Document 2) can be used.

[0048] After changing the transmission path bandwidth, the L3 / L2 switch control unit 46 instructs the L3 / L2 switches 10A and 10B to change the bandwidth of the logical line. The L3 / L2 switches 10A and 10B that received the instruction change the bandwidth of the logical line. As a method for changing the logical line, for example, shaping / policing can be used in VLAN, and calendar configuration (Non-Patent Document 3) can be used in FlexE.

[0049] The above example is an example of a case where it is necessary to change the bandwidth of two logical lines at both ends of the communication path between the L3 / L2 switches and the transmission paths mapped to the two logical lines. In addition to this example, there are cases where the bandwidth of only the logical lines is changed, where the bandwidth of only the transmission paths is changed, where the bandwidth of only one of the two logical lines is changed, etc.

[0050] Next, a second embodiment will be described. As described above, in the second embodiment, the controller 40 does not determine and instruct a bandwidth change, but the L3 / L2 switch 10 and the transmission device 20 autonomously determine and instruct a bandwidth change. In the second embodiment, each device other than the controller 40 operates autonomously, thereby improving the bandwidth change speed and scalability.

[0051] <Device Configuration Example> Fig. 8 shows a configuration example of the L3 / L2 switch 10 in Example 2. As shown in Fig. 8, the L3 / L2 switch 10 in Example 2 includes a traffic acquisition unit 11, a logical line control unit 12, a bandwidth calculation unit 13, a logical line management unit 14, a controller communication unit 15, and a transmission device communication unit 16. When distinguishing between the L3 / L2 switch 10A and the L3 / L2 switch 10B, the reference symbols of the functional units included in the L3 / L2 switches 10A and 10B are appended with "A" and "B," respectively.

[0052] The traffic acquisition unit 11 acquires traffic information of each logical line connected to the L3 / L2 switch 10. The logical line control unit 12 controls the logical lines. The control by the logical line control unit 12 includes setting / deleting logical lines and changing the bandwidth of already set logical lines.

[0053] The bandwidth calculation unit 13 uses the traffic data acquired by the traffic acquisition unit 11 to calculate the bandwidth required to transmit the traffic. For example, if the traffic is traffic flowing through logical line #1 and transmission path #A, the "required bandwidth" is the bandwidth required for logical line #1 and transmission path #A. To calculate the bandwidth, for example, a prediction algorithm using historical information is used. Furthermore, the bandwidth calculation unit 13 compares the required bandwidth with the current bandwidth to determine whether a bandwidth change is required.

[0054] The logical line management unit 14 manages logical lines, the bandwidth set for the logical lines, the traffic flowing through the logical lines, the transmission paths mapped to the logical lines, the device IDs of the endpoints of the transmission paths (IDs of the transmission devices on the target L3 / L2 switch 10 side), and the bandwidths of the transmission paths. In Figures 3 to 5, the "logical line, logical line bandwidth, traffic, device ID, transmission path ID, and transmission path bandwidth" corresponding to the target L3 / L2 switch 10 correspond to the information managed by the logical line management unit 14. An entry is added to the logical line management unit 14 when a logical line is set up or deleted.

[0055] The controller communication unit 15 communicates with the controller 40. This communication includes communication for notifying that the bandwidth of the logical line has been changed. The transmission device communication unit 16 communicates with the transmission device 20. This communication includes sending a bandwidth change instruction to the adjacent transmission device 20 and receiving a response to the instruction. The transmission device communication unit 16 may also be called a "communication unit."

[0056] 9 illustrates a configuration example of a transmission device 20 according to the second embodiment. As illustrated in FIG. 9, the transmission device 20 according to the second embodiment includes a transmission path control unit 21, a transmission path management unit 22, a controller communication unit 23, a transmission device communication unit 24, and an L3 / L2 switch communication unit 25.

[0057] The transmission path control unit 21 controls the transmission paths, including setting / deleting a transmission path and changing the bandwidth of an already set transmission path.

[0058] The transmission path management unit 22 manages transmission paths, logical lines (local device side, remote device side) mapped to the transmission paths, the device ID of the transmission device on the remote device side of the transmission path, and the bandwidth of the transmission path. In Figures 4 and 5, the "logical line (local), transmission path ID, logical line (remote), remote side endpoint device ID, and bandwidth" corresponding to the target transmission device 20 correspond to the information managed by the transmission path management unit 22. In the transmission path management unit 22, an entry is added when a transmission path is set up / deleted.

[0059] The controller communication unit 23 communicates with the controller 40. This communication includes notifying the controller 40 that the bandwidth of the transmission path has been changed.

[0060] The transmission device communication unit 24 communicates with adjacent transmission devices 20. This communication includes communication for arbitrating a bandwidth change between the adjacent transmission devices 20. "Arbitration" includes, for example, an exchange in which one transmission device 20 notifies another transmission device 20 of a desired bandwidth and receives an acknowledgement (or a proposal for a different bandwidth) from the other transmission device 20.

[0061] The L3 / L2 switch communication unit 25 communicates with the L3 / L2 switch 10. This communication includes receiving a bandwidth change instruction from an adjacent L3 / L2 switch 10 and sending a bandwidth change response to the L3 / L2 switch 10. The L3 / L2 switch communication unit 25 may also be called a "communication device communication unit."

[0062] <Operation Example> An operation example of the communication system in the second embodiment will be described with reference to Fig. 10. In S201 and S211, the traffic acquisition units 11A and 11B in the L3 / L2 switches 10A and 10B acquire traffic information of each logical line.

[0063] In S202 and S212, the bandwidth calculation units 13A and 13B of the L3 / L2 switches 10A and 10B calculate the required bandwidth of the communication path (logical line and transmission path) through which the traffic flows.

[0064] In S203 and S213, the bandwidth calculation units 13A and 13B of the L3 / L2 switches 10A and 10B determine whether a bandwidth change of the communication path is necessary and whether a bandwidth change is possible based on the available bandwidth of the transmission path (physical link / wavelength path). Here, it is assumed that a bandwidth change is possible.

[0065] Also, it is assumed here that both the L3 / L2 switches 10A and 10B have determined that a bandwidth change is necessary for a certain communication path (the determination results in S203 and S213 are Yes).

[0066] In S204, the transmission device communication unit 16A of the L3 / L2 switch 10A transmits a bandwidth change instruction for the transmission path to the transmission device 20A. In addition, in S214, the transmission device communication unit 16B of the L3 / L2 switch 10B transmits a bandwidth change instruction for the transmission path to the transmission device 20B.

[0067] In S205 and S215, the transmission device communication units 24A and 24B arbitrate and determine the amount of bandwidth change between the transmission device 20A and the transmission device 20B. The arbitration of the amount of bandwidth change includes determining whether or not a bandwidth change based on available bandwidth is possible.

[0068] In S206 and S216, the bandwidth of the transmission paths is changed between the transmission devices 20 A and 20 B. As a method for changing the transmission path bandwidth, for example, Hitless Adjustment ODUflex (Non-Patent Document 2) is used.

[0069] In S207, the L3 / L2 switch communication unit 25A of the transmission device 20A transmits a transmission path bandwidth change response to the L3 / L2 switch 10A. Also, in S207, the L3 / L2 switch communication unit 25B of the transmission device 20B transmits a transmission path bandwidth change response to the L3 / L2 switch 10B.

[0070] In S208 and S218, the logical line control units 12A and 12B of the L3 / L2 switches 10A and 10B change the bandwidth of the logical line mapped to the transmission path for which the bandwidth has been changed. As a method for changing the bandwidth of the logical line, for example, shaping / policing can be used in VLAN, and calendar configuration (see Non-Patent Document 3) can be used in FlexE.

[0071] In S209, each device transmits a notification to the controller 40 indicating that the bandwidth has been changed.

[0072] In the above example, both the L3 / L2 switch 10A and the L3 / L2 switch 10B on both sides of the communication path determine that a bandwidth change is necessary, and transmit a bandwidth change instruction to the transmission devices 20A and 20B.

[0073] However, since synchronization processing is not performed between the L3 / L2 switch 10A and the L3 / L2 switch 10B, there are cases where only one of the L3 / L2 switches determines that a bandwidth change is necessary. There are also cases where one of the L3 / L2 switches first calculates that a bandwidth change is necessary, and then the other L3 / L2 switch determines that a bandwidth change is necessary after a delay.

[0074] In the above case, one of the two transmission devices is in a state where it has not received a bandwidth change instruction. During the bandwidth change arbitration in S205 and S215, the transmission device that has not received a bandwidth change instruction can take the following measures, for example, Method A or Method B.

[0075] Method A: When an arbitration notification is received from the opposite transmission device, a timer is started and an instruction from the adjacent L3 / L2 switch is waited for until the timer expires.

[0076] Method B: When an arbitration notification is received from the opposing transmission device, communication is performed with the adjacent L3 / L2 switch, and based on the information obtained from the adjacent L3 / L2 switch, bandwidth change arbitration is performed with the opposing transmission device and the amount of bandwidth change is determined.

[0077] In addition, instead of two L3 / L2 switches on both sides of the communication path determining the band change as in the example of Figure 10, only one of the two L3 / L2 switches on both sides of the communication path may determine the band change.

[0078] (Hardware Configuration Example) Any of the devices described in this embodiment (the controller 40, the L3 / L2 switch 10, and the transmission device 20) can be realized by, for example, causing a computer to execute a program. This computer may be a physical computer or a virtual machine on a cloud.

[0079] That is, the device can be realized by executing a program corresponding to the processing performed by the device using hardware resources such as a CPU and memory built into a computer. The program can be recorded on a computer-readable recording medium (such as a portable memory) and stored or distributed. The program can also be provided via a network such as the Internet or email.

[0080] Fig. 11 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 11 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected via a bus B. The computer may further include a GPU.

[0081] The program that realizes the processing on the computer is provided by a recording medium 1001, such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0082] The memory device 1003 reads and stores a program from the auxiliary storage device 1002 when an instruction to start the program is received. The CPU 1004 realizes functions related to the device in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network, etc. The display device 1006 displays a GUI (Graphical User Interface) or the like according to the program. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the results of calculations.

[0083] (Effects of the embodiment) In conventional technology, the control of the L3 / L2 switch and the control of the transmission device are independent, making it impossible to quickly change the bandwidth to accommodate traffic that changes dynamically from moment to moment. In contrast, the technology of this embodiment makes it possible to link the control of the L3 / L2 switch and the control of the transmission device, thereby making it possible to quickly change the bandwidth to accommodate traffic that changes dynamically from moment to moment.

[0084] The following additional notes are provided regarding the above-described embodiments.

[0085] <Additional Notes> (Additional Note 1) A control device that controls a communication system including a communication device, a first transmission device connected to the communication device by a logical line, and a second transmission device connected to the first transmission device by a transmission path, the control device comprising: a management unit that manages mapping information between the logical line and the transmission path, the bandwidth of the logical line, and the bandwidth of the transmission path; a bandwidth calculation unit that determines whether a bandwidth change is necessary for the logical line or the transmission path based on traffic on the logical line and information managed by the management unit; and a control unit that implements the bandwidth change for the logical line or the transmission path when the bandwidth change is necessary. (Supplementary Item 2) A communication device in a communication system including a communication device and a transmission device connected to the communication device by a logical line and connected to other transmission devices by a transmission path, the communication device comprising: a traffic acquisition unit that acquires traffic information of the logical line, a bandwidth calculation unit that determines whether a bandwidth change of the transmission path is necessary based on the traffic information, and a communication unit that instructs the transmission device to change the bandwidth of the transmission path when the bandwidth change is necessary. (Supplementary Item 3) A communication device in a communication system including a communication device and a transmission device connected to the communication device by a logical line and connected to other transmission devices by a transmission path, the communication device comprising: a communication device communication unit that receives an instruction to change the bandwidth of the transmission path from the communication device that has determined that a bandwidth change of the transmission path is necessary based on traffic information of the logical line, and a transmission device communication unit that arbitrates for the bandwidth change with the other transmission devices based on the instruction.(Addendum 4) A control method executed by a control device that controls a communication system including a communication device, a first transmission device connected to the communication device by a logical line, and a second transmission device connected to the first transmission device by a transmission path, wherein the control device has a management unit that manages mapping information between the logical line and the transmission path, the bandwidth of the logical line, and the bandwidth of the transmission path, and the control method comprises the steps of: determining whether a bandwidth change is necessary for the logical line or the transmission path based on traffic on the logical line and information managed by the management unit; and, if the bandwidth change is necessary, implementing the bandwidth change for the logical line or the transmission path.

[0086] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0087] 10A, 10B L3 / L2 switch 11 Traffic acquisition unit 12 Logical line control unit 13 Bandwidth calculation unit 14 Logical line management unit 15 Controller communication unit 16 Transmission device communication unit 20A, 20B Transmission device 21 Transmission path control unit 22 Transmission path management unit 23 Controller communication unit 24 Transmission device communication unit 25 L3 / L2 switch communication unit 30 NMS 40 Controller 41 Bandwidth calculation unit 42 L3 / L2 switch management unit 43 Transmission device management unit 44 Transmission path management unit 45 Traffic acquisition unit 46 L3 / L2 switch control unit 47 Transmission device control unit 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims

1. A control device that controls a communication system including a communication device, a first transmission device connected to the communication device via a logical line, and a second transmission device connected to the first transmission device via a transmission path, comprising: a management unit that manages mapping information between the logical line and the transmission path, the bandwidth of the logical line, and the bandwidth of the transmission path; a bandwidth calculation unit that determines whether a bandwidth change is necessary for the logical line or the transmission path based on traffic on the logical line and information managed by the management unit; and a control unit that implements the bandwidth change for the logical line or the transmission path when the bandwidth change is necessary.

2. A communication device in a communication system including a communication device and a transmission device connected to the communication device by a logical line and connected to another transmission device by a transmission path, the communication device comprising: a traffic acquisition unit that acquires traffic information of the logical line; a bandwidth calculation unit that determines whether a bandwidth change for the transmission path is necessary based on the traffic information; and a communication unit that instructs the transmission device to change the bandwidth for the transmission path when the bandwidth change is necessary.

3. A transmission device in a communication system including a communication device and a transmission device connected to the communication device by a logical line and connected to another transmission device by a transmission path, the transmission device comprising: a communication device communication unit that receives an instruction to change the bandwidth of the transmission path from the communication device that has determined that a bandwidth change of the transmission path is necessary based on traffic information of the logical line; and a transmission device communication unit that performs arbitration for the bandwidth change with the other transmission device based on the instruction.

4. A control method executed by a control device that controls a communication system including a communication device, a first transmission device connected to the communication device via a logical line, and a second transmission device connected to the first transmission device via a transmission path, wherein the control device has a management unit that manages mapping information between the logical line and the transmission path, the bandwidth of the logical line, and the bandwidth of the transmission path, and the control method comprises the steps of: determining whether a bandwidth change is necessary for the logical line or the transmission path based on traffic on the logical line and information managed by the management unit; and, if the bandwidth change is necessary, implementing the bandwidth change for the logical line or the transmission path.

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