Communication control device, communication control method, and program

Abstract

A communication control device according to an embodiment includes a device setting unit and a resource release unit. The device setting unit: sets each of a first device and a second device, which transmit and receive an optical signal, in a state in which a first port and a first light wavelength are used or not used; stores setting contents regarding an executed setting in a first database; receives, from the first device, a report of a use status of the first device regarding the first port and the first light wavelength; acquires the setting contents from the first database; and compares the reported use status with the acquired setting contents. If the reported use status and the acquired setting contents do not correspond with each other, the resource release unit requests the device setting unit to set the second device in the state in which the first port and the first light wavelength are not used.

Description

Communication control device, communication control method, and program

[0001] The embodiments relate to a communication control device, a communication control method, and a program.

[0002] Optical communication systems that use optical lines are known. In optical communication systems, a terminal that transmits a signal and a terminal that receives the signal are connected via multiple optical fibers and multiple optical switches. The optical switches can switch the combination of optical fibers and optical wavelengths that make up the communication path between the transmitting terminal and the receiving terminal. Communication on the communication path is carried out using only optical signals.

[0003] When a communication path is established between a transmitting terminal and a receiving terminal, a communication control device of the optical communication system configures each optical switch on the communication path to use the same combination of optical fiber and optical wavelength (i.e., communication resources). While the communication path is established, the optical switches continue to use the configured communication resources. The communication control device stores, for each optical switch, information specifying the communication resources used by that optical switch.

[0004] An optical switch may fail. When the failed optical switch recovers from the failure, the communication control device updates information about the latest status of the recovered optical switch. For example, the recovered optical switch is recognized by the communication control device as being in a state where it is not using the communication resources that it was using before the failure.

[0005] Patent No. 6279982

[0006] When an optical switch that constitutes a communication path fails and then recovers, the other optical switches that constituted that communication path retain the communication resources that were set up when the communication path was established. However, when the optical switch fails, the communication path becomes invalid, and the communication resources are no longer in use, i.e., communication resources become floating. For this reason, the release of communication resources is required, and the communication control device requires information for controlling the release of communication resources.

[0007] In the case of telecommunications such as Internet Protocol (IP) using optical lines, a router on the communication path converts optical signals into electrical signals. Therefore, by reading the header information of the converted electrical signals, the router can obtain information about the communication path, such as the transmitting terminal, the path, and the receiving terminal. This information can be used by the communication control device.

[0008] However, in optical communication systems where communication between a transmitting terminal and a receiving terminal is carried out using only optical signals, optical switches do not perform photoelectric conversion. Therefore, optical switches cannot obtain information about communication paths. Therefore, communication control devices cannot obtain information about communication paths, and therefore cannot release resources that are not being used for communication.

[0009] The present invention has been made in view of the above circumstances, and its object is to provide a means for releasing unused communication resources in an optical communication system.

[0010] According to an embodiment, a communication control device includes a device setting unit and a resource release unit. The device setting unit sets a first device and a second device that transmit and receive optical signals to a state in which a first port and a first optical wavelength are used or not used, stores setting contents for the executed setting in a first database, receives a report from the first device about a usage status of the first port and the first optical wavelength of the first device, acquires the setting contents from the first database, and compares the reported usage status with the acquired setting contents. If the reported usage status and the acquired setting contents do not match, the resource release unit requests the device setting unit to set the second device to a state in which the first port and the first optical wavelength are not used.

[0011] According to the embodiment, it is possible to provide a means for releasing unused communication resources in an optical communication system.

[0012] FIG. 1 shows an example of components included in an optical communication system according to the first embodiment. FIG. 2 shows an example of the hardware configuration of a user terminal device included in the optical communication system according to the first embodiment. FIG. 3 shows an example of the hardware configuration of an optical transfer device included in the optical communication system according to the first embodiment. FIG. 4 shows an example of the hardware configuration of a communication control device included in the optical communication system according to the first embodiment. FIG. 5 shows an example of the functional configuration of an optical transfer device included in the optical communication system according to the first embodiment. FIG. 6 shows an example of the functional configuration of a communication control device included in the optical communication system according to the first embodiment. FIG. 7 shows signals transmitted and received during operation in the optical communication system according to the first embodiment. FIG. 8 shows an operation flow of the optical communication system according to the first embodiment. FIG. 9 shows signals transmitted and received during operation in the optical communication system according to the first embodiment. FIG. 10 shows an operation flow of the optical communication system according to the first embodiment. FIG. 11 shows signals transmitted and received during operation in the optical communication system according to the first embodiment. FIG. 12 shows signals transmitted and received during operation in the optical communication system according to the first embodiment. FIG. 13 shows signals transmitted and received during operation in the optical communication system according to the first embodiment. FIG. 14 shows an operation flow of the optical communication system according to the first embodiment. Fig. 15 shows a flow of operations of the optical communication system according to the first embodiment. Fig. 16 shows an example of the functional configuration of a communication control unit included in the optical communication system according to the second embodiment.

[0013] Hereinafter, embodiments will be described with reference to the drawings. In order to distinguish between multiple components having substantially the same functions and configurations in a certain embodiment or different embodiments, additional numbers or letters may be added to the end of the reference numeral. Any description of one embodiment also applies to the description of another embodiment, unless explicitly or obviously excluded.

[0014] Additionally, any steps in the method flows of the embodiments are not limited to the illustrated order and may occur in an order different from the illustrated order and / or in parallel with other steps unless otherwise indicated.

[0015] 1. First Embodiment 1.1. Configuration (Structure) 1.1.1. Configuration of the Communication System FIG. 1 shows an example of components included in an optical communication system according to the first embodiment. The optical communication system 1 is an optical communication network including a communication control device 5, user terminal devices 6 (6a and 6b), multiple optical transfer devices 7, and multiple optical fibers 8. FIG. 1 shows only two user terminal devices 6a and 6b that communicate as the user terminal devices 6. The communication path between the user terminal devices 6a and 6b includes any number of optical transfer devices 7. FIG. 1 shows an example in which the communication path between the user terminal devices 6a and 6b includes a total of two optical transfer devices 7a and 7b.

[0016] The communication control device 5 is, for example, a server installed in a telecommunications carrier's office. The communication control device 5 is connected to the user terminal device 6 and the optical transfer device 7 so as to be able to communicate with them by any means. The communication control device 5 controls the user terminal device 6 and the optical transfer device 7.

[0017] The user terminal device 6 is a terminal used by a user to transmit and receive signals by optical communication. The user terminal device 6 is, for example, an ONU (Optical Network Unit). The user terminal device 6 has one or more ports.

[0018] The optical transfer device 7 is a device that receives an optical signal propagating through an optical fiber 8 and outputs the received optical signal to another optical fiber 8. The optical transfer device 7 is configured to be able to dynamically select one of a plurality of optical wavelength signals that the optical fiber 8 can transmit, and to be able to receive and transmit the selected one. The optical transfer device 7 can be in a state where it uses one of a plurality of optical fibers 8 and one of a plurality of optical wavelengths. The optical transfer device 7 uses the optical fiber 8 and the specified optical wavelength specified by the communication control device 5. The optical transfer device 7 has one or more ports.

[0019] The optical fibers 8 are cables that transmit optical signals. Each optical fiber 8 can transmit light of multiple different wavelengths. One end of each optical fiber 8 is connected to a user terminal device 6 or an optical transfer device 7, and the other end is connected to another user terminal device 6 or another optical transfer device 7. Two of the user terminal devices 6 and the optical transfer devices 7 are connected by one optical fiber 8. One end of each optical fiber 8 is connected to one port of the user terminal device 6 or the optical transfer device 7, and the other end is connected to one port of the other user terminal device 6 or another optical transfer device 7.

[0020] 2 shows an example of the hardware configuration of a user terminal device included in the optical communication system according to the first embodiment. As shown in Fig. 2, the user terminal device 6 includes a central processing unit (CPU) 11, a read-only memory (ROM) 12, a random access memory (RAM) 13, an optical communication module 14, and a communication module 15.

[0021] The CPU 11 is an integrated circuit capable of executing various programs. By executing the programs, the CPU 11 controls the overall operation of the user terminal device 6. By the CPU 11 executing the programs stored in the ROM 12 and loaded onto the RAM 13, the user terminal device 6 performs various operations and functions as various functional blocks.

[0022] The ROM 12 is a non-volatile memory that stores programs and data such as control data for controlling the user terminal device 6. The RAM 13 is a volatile memory that temporarily stores data. The RAM 13 also functions as a work area for the CPU 11.

[0023] The optical communications module 14 is a circuit and device for communicating using optical signals. The optical communications module 14 is connected to an optical fiber 8 and is configured to be able to transmit and receive optical signals via the optical fiber 8. The optical communications module 14 converts electrical signals that a user terminal device 6 wishes to transmit to another user terminal device 6 into optical signals and outputs the converted optical signals to the optical fiber 8. The optical communications module 14 receives optical signals from the optical fiber 8. The optical communications module 14 is configured to be able to transmit and receive optical signals having one of a plurality of ports and a dynamically selected one of a plurality of optical wavelengths. Figure 2 shows only one port P1.

[0024] The communication module 15 is a circuit and device for communicating between the user terminal device 6 and the communication control device 5. The communication module 15 is configured to be able to communicate with the communication control device 5 via wire and / or wirelessly.

[0025] 3 shows an example of the hardware configuration of the optical transfer device included in the optical communication system according to the first embodiment. As shown in FIG. 3, the optical transfer device 7 includes a CPU 21, a ROM 22, a RAM 23, an optical switch 24, and a communication module 25.

[0026] The CPU 21 is an integrated circuit that can execute various programs. By executing the programs, the CPU 21 controls the overall operation of the optical transfer device 7. By the CPU 21 executing the programs stored in the ROM 22 and loaded onto the RAM 23, the optical transfer device 7 performs various operations and functions as various functional blocks.

[0027] The ROM 22 is a non-volatile memory that stores data such as programs and control data for controlling the optical transfer device 7. The RAM 23 is a volatile memory that temporarily stores data. The RAM 23 also functions as a work area for the CPU 21.

[0028] The optical switch 24 is a device for receiving and transmitting optical signals. The optical switch 24 is connected to optical fibers 8 at each of a plurality of ports. The optical switch 24 outputs an optical signal received at a dynamically selected one of the plurality of ports from a dynamically selected one of the plurality of ports. The optical switch 24 is configured to be able to receive and transmit an optical signal having a dynamically selected one of a plurality of optical wavelengths. Fig. 2 shows only two ports P1 and P2. One of the ports P1 and P2 functions as an input port, and the other functions as an output port.

[0029] The communication module 25 is a circuit and device for communicating between the optical transfer device 7 and the communication control device 5. The communication module 25 is configured to be able to communicate with the communication control device 5 by wire and / or wirelessly.

[0030] 4 shows an example of the hardware configuration of the communication control device included in the optical communication system according to the first embodiment. As shown in FIG. 4, the communication control device 5 includes a CPU 31, a ROM 32, a RAM 33, and a communication module 34.

[0031] The CPU 31 is an integrated circuit capable of executing various programs. By executing the programs, the CPU 31 controls the overall operation of the communication control device 5. By the CPU 31 executing the programs stored in the ROM 32 and loaded onto the RAM 33, the communication control device 5 performs various operations and functions as various functional blocks.

[0032] The ROM 32 is a non-volatile memory that stores data such as programs and control data for controlling the communication control device 5. The RAM 33 is a volatile memory that temporarily stores data. The RAM 33 also functions as a work area for the CPU 31.

[0033] The communication module 34 is a circuit and device for performing communication between the communication control device 5 and the user terminal device 6, and communication between the communication control device 5 and the optical transfer device 7. The communication module 34 is configured to be able to communicate with the user terminal device 6 and the optical transfer device 7 by wire and / or wirelessly.

[0034] 5 shows an example of the functional configuration of an optical transfer device included in the optical communication system according to the first embodiment. As shown in FIG. 5, during operation, the optical transfer device 7 functions as a device including an optical switch control unit 28 as a functional block in addition to the optical switch 24 and the communication module 25. The optical switch control unit 28 controls the optical switch 24 to be in the instructed setting state based on the setting instruction (e.g., the port to be used and the optical wavelength to be used) received by the communication module 25.

[0035] 1.1.6 Functional Configuration of the Communication System Fig. 6 shows an example of the functional configuration of a communication control device included in the optical communication system according to the first embodiment. As shown in Fig. 6, while the communication control device 5 is operating, it functions as a device including functional blocks such as a setting request processing unit 110, a communication path resolution unit 120, a matching processing unit 130, a resource shortage resolution unit (resource release unit) 140, a device setting unit 150, a setting history management database 160, and a device status management database 170. The setting request processing unit 110, the communication path resolution unit 120, the matching processing unit 130, the resource shortage resolution unit 140, the device setting unit 150, the setting history management database 160, and the device status management database 170 are each realized by execution of a program by the CPU 11 and / or by part of the storage area of ​​the RAM 13.

[0036] The setting request processing unit 110 is a functional block that processes setting requests received by the communication control device 5. The setting request requests that the user terminal device 6 and the optical transfer device 7 managed by the communication control device 5 be set to a certain state.

[0037] The communication path resolution unit 120 is a functional block that determines a communication path for performing communication scheduled to be executed and notified to the communication control device 5. To determine the communication path, the communication path resolution unit 120 determines the optical transfer device 7 in the communication path, the ports used by each of the user terminal device 6 and the optical transfer device 7 in the communication path, and the optical wavelength to be used in the communication path.

[0038] The consistency processing unit 130 is a functional block that processes a consistency request received by the communication control device 5. The consistency request requests that the status stored in the communication control device 5 for each of the user terminal devices 6 and optical transfer devices 7 managed by the communication control device 5 be consistent with the current status of each of the user terminal devices 6 and optical transfer devices 7.

[0039] The resource deficiency resolution unit 140 is a functional block that performs processing to resolve resource deficiency when it is determined that resource deficiency has occurred. Resource deficiency refers to a state in which communication resources are secured but no communication path using those communication resources exists. The resource deficiency resolution unit 140 includes a resource deficiency determination unit 141 and a resource deficiency resolution processing unit 142. The resource deficiency determination unit 141 is a functional block that determines whether resource deficiency has occurred in the device that is the subject of the determination. The resource deficiency resolution processing unit 142 is a functional block that performs processing to resolve the resource deficiency of a device when it is determined that resource deficiency has occurred in the device.

[0040] The device setting unit 150 is a functional block that sets various states for each of the user terminal devices 6 and optical transfer devices 7 managed by the communication control device 5. The setting includes instructing the device to reserve or open a specific port, and instructing the device to use a specific frequency on the reserved port.

[0041] The setting history management database 160 stores the contents of the setting (i.e., the most recent setting) in the form of a history each time a setting is made for each of the user terminal devices 6 and optical transfer devices 7 managed by the communication control device 5.

[0042] The device status management database 170 stores the configuration details for each of the user terminal devices 6 and optical transfer devices 7 managed by the communication control device 5. The configuration details include the combination of the port and optical wavelength being used for each of the user terminal devices 6 and optical transfer devices 7.

[0043] 2. Operation 2.1. Normal Operation This section describes the normal operation during communication.

[0044] 2.1.1. At the Start of Communication FIG. 7 shows signals transmitted and received during operation of the optical communication system according to the first embodiment. Specifically, FIG. 7 shows the operation when communication starts. FIG. 7 shows only optical transfer devices 7a and 7b included in the communication path determined at the start of communication as the optical transfer devices 7.

[0045] The setting request processing unit 110 receives a setting request (S1). The setting request is transmitted, for example, when communication is initiated in a state where a communication path has not been established, and requests the establishment of a communication path. The setting request is transmitted, for example, by a user terminal device 6 that wishes to initiate communication, or by another system of a network operator.

[0046] When the setting request processor 110 receives the setting request, it requests the communication path resolution processor 120 to resolve the communication path (S2).

[0047] When the communication path resolution unit 120 is requested to resolve a communication path, it determines the communication path (S3). The determination of the communication path includes determining the optical transfer devices 7 included in the communication path, the ports used by each of the user terminal devices 6 and the optical transfer devices 7 in the communication path, and the optical wavelengths used in the communication path. As described above, the determined communication path includes, for example, the optical transfer devices 7a and 7b. Information about the determined communication path is sent to the setting request processing unit 110. The user terminal device 6a, the optical transfer devices 7a and 7b, and the user terminal device 6b are assigned device identifiers, for example, device 001, device 002, device 003, and device 004, respectively.

[0048] When the setting request processing unit 110 receives the communication path information, it requests the device setting unit 150 to perform settings for securing communication resources based on the communication path information (S4). Specifically, the setting request processing unit 110 requests the device setting unit 150 to perform settings for securing communication resources for the user terminal devices 6 and optical transfer devices 7 on the communication path based on the communication path information.

[0049] When the device setting unit 150 is requested to perform the setting, it performs the setting for the user terminal device 6 and the optical transport device 7 in accordance with the request (S5). By performing the setting, the user terminal device 6 and the optical transport device 7 secure the set port and optical wavelength. Therefore, the set port changes to a used status. For example, the user terminal device 6 uses wavelength A at port P1, and the optical transport device 7 uses wavelength A at ports P1 and P2, respectively.

[0050] Additionally, each of the user terminal device 6 and the optical transfer device 7 stores information identifying the performed configuration. Examples of the information include the date and time the configuration was performed and a unique identifier.

[0051] The device setting unit 150 updates the device status management database 170 (S6). Specifically, the device setting unit 150 updates the settings for the user terminal device 6 and the optical transfer device 7 in the device status management database 170 with the settings that have been executed (i.e., the current settings). The settings include the ports that are being used and the optical wavelengths that are being used at the ports that are being used.

[0052] The device setting unit 150 updates the setting history management database 160 (S7). Specifically, the device setting unit 150 adds the contents of the settings performed for the user terminal device 6 and the optical transfer device 7 (i.e., the current settings) to the setting history management database 160 as the latest setting history.

[0053] After this, communication takes place.

[0054] FIG. 8 shows the flow of the operation of the optical communication system according to the first embodiment, and shows the flow for the case of FIG.

[0055] In step S1, the setting request processor 110 receives a setting request.

[0056] In step S2, the setting request processor 110 requests the communication path resolution unit 120 to resolve a communication path.

[0057] In step S3, the communication path determination unit 120 determines a communication path, and sends information about the communication path to the setting request processing unit 110.

[0058] In step S4, the setting request processor 110 requests the device setting unit 150 to execute settings for securing communication resources based on the information about the communication path.

[0059] In step S5, the device setting unit 150 sets the target user terminal device 6 and optical transfer device 7 to the requested state.

[0060] In step S6, the device setting unit 150 updates the device status management database 170 with the current settings for the user terminal device 6 and optical transfer device 7 that are the targets of the settings.

[0061] In step S7, the device setting unit 150 updates the setting history management database 160 by adding the content updated in step S6 as the latest setting history. Upon completion of step S7, the flow ends.

[0062] 2.1.2 End of Communication Fig. 9 shows signals transmitted and received during operation of the optical communication system according to the first embodiment. Specifically, Fig. 9 shows the operation when communication is ended.

[0063] The setting request processing unit 110 receives a setting request (S11). The setting request is transmitted, for example, when a process for terminating communication is initiated, and requests the release of a communication path. The setting request is transmitted, for example, by a user terminal device 6 that wishes to terminate communication, or by another system of a network operator.

[0064] When the setting request processing unit 110 receives a setting request, it refers to the setting history management database 160 to determine the user terminal device 6 and optical transfer device 7 in the communication path that is being requested to be opened in the setting request, the port being used, and the optical wavelength being used (S12).

[0065] The setting request processing unit 110 requests the device setting unit 150 to perform settings for releasing communication resources based on the acquired information about the communication path (S13). Specifically, the setting request processing unit 110 requests the device setting unit 150 to perform settings for releasing communication resources for the user terminal device 6 and the optical transfer device 7.

[0066] When the device setting unit 150 is requested to execute the setting, it executes the setting for the user terminal device 6 and the optical transfer device 7 in accordance with the request (S14). By executing the setting, the user terminal device 6 and the optical transfer device 7 change to a state in which they are not using the port and optical wavelength that were used to secure the communication path. This ends the communication.

[0067] Additionally, each of the user terminal device 6 and the optical transfer device 7 stores information identifying the performed configuration. Examples of the information include the date and time the configuration was performed and a unique identifier.

[0068] The device setting unit 150 updates the device status management database 170 (S15). Specifically, the device setting unit 150 updates the settings for the user terminal device 6 and the optical transfer device 7 in the device status management database 170 with the settings that have been executed (i.e., the current settings). The settings include information indicating that the ports and optical wavelengths that were used are now unused.

[0069] The device setting unit 150 updates the setting history management database 160 (S16). Specifically, the device setting unit 150 adds the contents of the settings performed for the user terminal device 6 and the optical transfer device 7 (i.e., the current settings) to the setting history management database 160 as the latest setting history.

[0070] FIG. 10 shows the flow of the operation of the optical communication system according to the first embodiment, and shows the flow for the case of FIG.

[0071] In step S11, the setting request processor 110 receives a setting request.

[0072] In step S12, the setting request processing unit 110 obtains from the setting history management database 160 the user terminal device 6 and optical transfer device 7 in the communication path that is being requested to be opened in the setting request, the port being used, and the optical wavelength being used.

[0073] In step S13, the setting request processing unit 110 requests the device setting unit 150 to execute settings for releasing communication resources based on the acquired information.

[0074] In step S14, the device setting unit 150 sets the target user terminal device 6 and optical transfer device 7 to the requested state.

[0075] In step S15, the device setting unit 150 updates the device status management database 170 with the current settings for the user terminal device 6 and optical transfer device 7 that are the targets of the settings.

[0076] In step S16, the device setting unit 150 updates the setting history management database 160 by adding the content updated in step S15 as the latest setting history. Upon completion of step S16, the flow ends.

[0077] 11, 12, and 13 show signals transmitted and received during operation of the optical communication system according to the first embodiment. More specifically, FIGS. 11 to 13 show the matching operation. The matching operation refers to the operation of matching the actual state of the devices on the communication path with information about the devices on the communication path stored in the communication control device.

[0078] The setting request processing unit 110 receives a matching request (S21). The matching request is sent, for example, by another system of the network operator, when a device that constitutes a certain communication path fails and then recovers. The matching request includes information that identifies the optical transfer device 7 that has recovered after the failure as the target of the matching request. Figures 11 to 13 and the following description are based on an example in which the target of the matching request is the optical transfer device 7a.

[0079] When the setting request processing unit 110 receives the matching request, it requests the matching processing unit 130 to perform matching processing (S22). The matching processing request includes information that identifies one or more optical transfer devices 7 that are the targets of the matching processing, that is, the optical transfer device 7a in this example.

[0080] When the matching processing is requested, the matching processing unit 130 requests the device setting unit 150 to execute a matching processing command (S23). The matching processing command includes information that identifies one or more optical transfer devices 7 that are targets of the matching processing, that is, the optical transfer device 7a in this example.

[0081] When the device setting unit 150 is requested to execute the matching processing command, it transmits the matching processing command to all optical transfer devices 7 specified in the request (S24).

[0082] The optical transfer device 7a that received the matching processing command reports to the device setting unit 150 whether all of its ports are currently in use and the optical wavelengths used for the ports that are in use (S25). Furthermore, the optical transfer device 7a that received the matching processing command reports to the device setting unit 150 information indicating the date and time of the most recent setting or an identifier that identifies the most recent setting.

[0083] The device setting unit 150 acquires the setting details for the optical transfer device 7a from the device status management database 170 (S26).

[0084] The device setting unit 150 compares the usage status reported by the optical transfer device 7a with the settings acquired from the device status management database 170 (S27). If the usage status reported by the optical transfer device 7a matches the settings acquired from the device status management database 170, the matching process ends. The following description of FIGS. 11 to 13 and 11 to 13 shows the case where the usage status reported by the optical transfer device 7a does not match the settings acquired from the device status management database 170 with respect to the subsequent processing.

[0085] Based on the fact that the usage status reported from the optical transfer device 7a does not match the setting contents acquired from the device status management database 170, the device setting unit 150 updates the device status management database 170 based on the reported usage status (S28).

[0086] The device setting unit 150 updates the setting history management database 160. Specifically, the device setting unit 150 adds information indicating the usage status reported by the optical transfer device 7a to the setting history management database 160 as the latest setting history (S29).

[0087] The device setting unit 150 transmits to the consistency processing unit 130 a consistency processing result indicating that the usage status reported from the optical transfer device 7a does not match the setting contents acquired from the device status management database 170 (S30).

[0088] If the consistency processing result indicates a mismatch, this indicates that there may be a shortage of communication resources. Based on this, when the consistency processing unit 130 receives a consistency processing result indicating a mismatch, it requests the resource shortage resolution unit 140 to resolve the resource shortage (S31). The request to resolve the resource shortage includes information that identifies the optical transfer device 7 whose usage status does not match the stored settings, and information that indicates the combination of the port and optical wavelength used by the mismatched optical transfer device 7.

[0089] When the resource shortage resolution unit 140 receives a resource shortage resolution request, the resource shortage determination unit 141 identifies the optical transfer device 7 and the user terminal device 6 that are targets for resolving the resource shortage (S32). Specifically, the resource shortage determination unit 141 identifies the latest information about the communication path including the optical transfer device 7 whose setting contents and usage status do not match from the setting history management database 160 based on information that identifies the optical transfer device 7 whose stored setting contents and usage status do not match. The identified information includes information that identifies the optical transfer device 7 and the user terminal device 6 in the communication path including the optical transfer device 7 whose setting contents and usage status do not match, and the setting contents (used ports and optical wavelengths) for each of these optical transfer devices 7 and user terminal devices 6.

[0090] The resource free space determination unit 141 determines whether resource free space has occurred in each of the optical transfer device 7 and the user terminal device 6 based on the information acquired from the setting history management database 160 and the determination logic (S33). An example of the determination logic includes determining whether each of the optical transfer device 7 and the user terminal device 6 acquired from the setting history management database 160 has reserved (i.e., is in use) the optical wavelength of the port used in the communication path including the mismatched optical transfer device 7a. For example, if a certain device has reserved the optical wavelength of the port used in the communication path including the mismatched optical transfer device 7a, this device is determined to be experiencing resource free space. In the current example, it is determined that resource free space has occurred in the user terminal devices 6a and 6b and the optical transfer device 7b.

[0091] If there is a device that is determined to have resource shortage, the resource shortage determination unit 141 requests the resource shortage resolution processing unit 142 to resolve the resource shortage (S34). The resolution request includes information that identifies the device that is the target of resource shortage resolution, i.e., the device that is determined to have resource shortage, and information that identifies the combination of port and optical wavelength that is determined to have resource shortage.

[0092] When the resource shortage resolution processing unit 142 receives the resource shortage resolution request, it requests the device setting unit 150 to perform settings to resolve the resource shortage based on the resource shortage resolution request (S35). Specifically, the resource shortage resolution processing unit 142 requests the device setting unit 150 to perform settings for releasing the combination of ports and optical wavelengths specified in the resource shortage resolution request for the devices specified in the resource shortage resolution request, i.e., the user terminal devices 6 a and 6 b and the optical transfer device 7 b.

[0093] When the device setting unit 150 is requested to execute the setting, it executes the setting for the user terminal devices 6 a and 6 b and the optical transport device 7 b in accordance with the request (S36). By executing the setting, the set ports and optical wavelengths in the user terminal devices 6 a and 6 b and the optical transport device 7 b change to unused status.

[0094] The device setting unit 150 updates the device status management database 170 (S37). Specifically, the device setting unit 150 updates the settings for the user terminal devices 6a and 6b and the optical transfer device 7b in the device status management database 170 with the settings that have been executed (i.e., the current settings).

[0095] The device setting unit 150 updates the setting history management database 160 (S38). Specifically, the device setting unit 150 adds the contents of the settings performed for the user terminal devices 6 a and 6 b and the optical transfer device 7 b (i.e., the current settings) to the setting history management database 160 as the latest setting history.

[0096] 14 and 15 show the flow of the operation of the optical communication system according to the first embodiment, and specifically show the flow for the cases of FIGS. 11 to 13.

[0097] In step S21, the setting request processor 110 receives a matching request.

[0098] In step S22, the setting request processor 110 requests the consistency processor 130 to execute consistency processing.

[0099] In step S23, the consistency processing unit 130 requests the device setting unit 150 to execute a consistency processing command.

[0100] In step S24, the device setting unit 150 transmits a matching processing command to all identified optical transfer devices 7.

[0101] In step S25, the optical transfer device 7 that has received the matching processing command reports the usage status of the port and the optical wavelength to the device setting unit 150.

[0102] In step S26, the device setting unit 150 acquires the setting details for the identified optical transfer device 7 from the device status management database 170. Step S25 may be performed before step S26.

[0103] In step S27, device setting unit 150 compares the usage status reported by optical transfer device 7a with the settings acquired from device status management database 170. If the reported usage status and the acquired settings match (S27_Yes), the flow ends.

[0104] If the reported usage status and the acquired setting content do not match (No in S27), in Step S28, the device setting unit 150 updates the device status management database 170 based on the reported usage status.

[0105] In step S29 , the device setting unit 150 updates the setting history management database 160 .

[0106] In step S30, the device setting unit 150 transmits a consistency processing result indicating a mismatch to the consistency processing unit 130.

[0107] In step S31, the consistency processing unit 130 requests the resolution of the floating resource.

[0108] In step S32, the resource surplus determining unit 141 uses the setting history management database 160 to identify the optical transfer device 7 and / or the user terminal device 6 that are targets for resolving the resource surplus.

[0109] In step S33, the resource surplus determination unit 141 determines whether a resource surplus has occurred in the identified optical transfer device 7 and / or user terminal device 6 (S33). If no device is determined to have a resource surplus (S33_No), the flow ends.

[0110] If there is a device that is determined to be in a resource floating state (S34_Yes), then in step S34, the resource floating determination unit 141 requests the resource floating resolution processing unit 142 to resolve the resource floating state.

[0111] In step S35, the resource surplus resolution processing unit 142 requests the device setting unit 150 to execute settings for resolving the resource surplus.

[0112] In step S36, the device setting unit 150 sets the device to be set to the requested state.

[0113] In step S37, the device setting unit 150 updates the device status management database 170 with the current setting contents for the device to be set.

[0114] In step S38, the device setting unit 150 updates the setting history management database 160 by adding the content updated in step S37 as the latest setting history. Upon completion of step S37, the flow ends.

[0115] 1.3. Advantages of the Embodiment According to the first embodiment, as described below, it is possible to provide a means for releasing communication resources that are reserved despite not being used in an optical communication system.

[0116] An optical transfer device may fail and then recover. In this case, communication carried by the communication path that the failed optical transfer device formed a part of before the failure is performed by a communication path other than the communication path that the failed optical transfer device formed a part of before the failure. In this case, the communication path that was used before the failure of the optical transfer device is not used.

[0117] However, in an optical communication system, an optical transfer device does not convert an optical signal into an electrical signal, so the optical transfer device cannot acquire information about the communication path. Therefore, the communication control device cannot acquire information about the communication path from the optical transfer device. Therefore, the communication control device cannot acquire information about the communication path that was used before the failure of the optical transfer device, and cannot release communication resources for the communication path that was used before the failure of the optical transfer device.

[0118] According to the first embodiment, the communication control device 5 stores the setting details of the devices on the communication path in the device status management database 170 each time a communication path is secured and released, and also stores the setting details in the form of a history in the setting history management database 160. For example, when the communication control device 5 receives a matching request after a certain device has recovered from a failure, it can use the device status management database 170 and the setting history management database 160 to identify the devices on the communication path before the failure and the setting details of those devices.

[0119] Since the communication control device 5 can identify devices, it can inquire about the current usage status of the identified devices. By comparing the usage status reported as a result of the inquiry with the stored settings, the communication control device 5 can determine whether communication resources for each device are being reserved but not used. By being able to make this determination, the communication control device 5 can release communication resources that have been reserved but are not being used.

[0120] 2. Second Embodiment Fig. 16 shows an example of the functional configuration of a user terminal device and an optical transfer device included in an optical communication system according to a second embodiment. Fig. 16 also shows signals transmitted and received during operation in the optical communication system according to the second embodiment.

[0121] 16, while the user terminal device 6 and the optical transfer device 7 are operating, each of them functions as a device that includes a setting history management database 29. Each time a setting is performed on the user terminal device 6 and the optical transfer device 7, the contents of the performed setting are added to the setting history management database 29 of the user terminal device 6 and the optical transfer device 7 as the latest setting history.

[0122] During the matching process, the device setting unit 150 instructs each of the user terminal device 6 and the optical transfer device 7 to transmit data in the setting history management database 29, for example, by a command, in accordance with a request from the matching processing unit 130, and acquires the data. The device setting unit 150 updates the setting history management database 160 using the acquired settings for each device.

[0123] According to the second embodiment, the same effects as those of the first embodiment can be obtained. Furthermore, according to the second embodiment, even if data in the setting history management database 160 is lost due to a failure of the communication control device 5, the setting history management database 160 can be reconstructed by receiving the data in the setting history management database 29 from each of the user terminal device 6 and the optical transfer device 7.

[0124] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0125] REFERENCE SIGNS LIST 1...optical communication system, 5...communication control device, 6...user terminal device, 7...optical transfer device, 8...optical fiber, 11, 21, 31...CPU, 12, 22, 32...ROM, 13, 23, 33...RAM, 14...optical communication module, 15...communication module, 24...optical switch, 25...communication module, 28...optical switch control unit, 29...setting history management database, 34...communication module, 110...setting request processing unit, 120...communication path resolution unit, 130...matching processing unit, 140...resource shortage resolution unit, 141...resource shortage determination unit, 142...resource shortage resolution processing unit, 150...device setting unit, 160...setting history management database, 170...device status management database

Claims

1. A communications control device comprising: a device setting unit that sets each of a first device and a second device that transmit and receive optical signals to a state in which a first port and a first optical wavelength are used or not used, stores setting contents for the executed setting in a first database, receives a report of the usage status of the first port and the first optical wavelength of the first device from the first device, acquires the setting contents from the first database, and compares the reported usage status with the acquired setting contents; and a resource float resolution unit that requests the device setting unit to set the first port and the first optical wavelength of the second device to a state in which they are not used if the reported usage status and the acquired setting contents do not match.

2. The communication control device of claim 1, wherein the device setting unit, when settings are performed on each of the first device and the second device, stores the settings for the performed settings in the form of a history in a second database; if the reported usage status does not match the acquired setting contents, uses first information identifying the first device to acquire information identifying the second device and the latest setting contents performed on the second device from the second database; and based on the latest setting contents, decides to set the first port and the first optical wavelength of the second device to a state in which they are not used.

3. The communication control device according to claim 2, wherein, when the device setting unit decides to set the first port and the first optical wavelength of the second device to a state in which they are not in use, the device setting unit sets the first port and the first optical wavelength of the second device to a state in which they are not in use, and updates the first database with information indicating that the first port and the first optical wavelength of the second device are not in use.

4. The communication control device according to claim 2, wherein the device setting unit updates the first database with information indicating that the first port and the first optical wavelength of the first device are not in use if the reported usage status and the acquired setting contents do not match.

5. The communication control device according to claim 1, wherein when the communication control device receives a matching request, the device setting unit instructs the first device to report the usage status of the first port and the first optical wavelength of the first device.

6. The communication control device according to claim 1, wherein the second device is a device that has recovered after a failure, and the first device and the second device are devices that were included in a communication path that used the first optical wavelength before the failure.

7. A communications control method comprising: setting a first device and a second device that transmit and receive optical signals to a state in which a first port and a first optical wavelength are used or not used; storing setting contents for the executed setting in a first database; receiving a report from the first device of the usage status of the first port and the first optical wavelength of the first device; acquiring the setting contents from the first database; comparing the reported usage status with the acquired setting contents; and, if the reported usage status and the acquired setting contents do not match, setting the first port and the first optical wavelength of the second device to a state in which they are not used.

8. A program for causing a communications control device to execute the following steps: setting a first device and a second device that transmit and receive optical signals to a state in which a first port and a first optical wavelength are used or not used; storing the setting contents for the executed setting in a first database; receiving a report from the first device on the usage status of the first port and the first optical wavelength of the first device; acquiring the setting contents from the first database; comparing the reported usage status with the acquired setting contents; and, if the reported usage status and the acquired setting contents do not match, setting the first port and the first optical wavelength of the second device to a state in which they are not used.

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