JP2015119234A - Communication device and fault recovery control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce control time of a communication device for recovering a path when a fault occurs in a transmission network.SOLUTION: A control command for a communication device and setting time by operation unit are managed as a DB table. When a fault occurs in a communication path, a bypass is determined so that setting time for the communication device for bypassing the communication path becomes short on the basis of a situation of the fault to reduce fault recovery time.

Description

  The present invention relates to control of a communication apparatus, and more particularly to a failure recovery method.

  In recent years, with the diversification of information services via communication networks, such as the spread of video distribution services using smartphones and high-performance televisions, and wide-area VLANs in corporate networks, public lines and dedicated connections between those terminals and servers Line transmission networks are required to have higher capacities and higher RAS functionality (Reliability, Reliability, Serviceability). The reliability of the transmission network indicates that the communication device is not easily broken and the communication is not interrupted. The maintainability of the transmission network indicates the ease with which the device can be repaired. The availability of the transmission network indicates a short service outage time of the user. In the field of RAS technology in a transmission network, a route control method is implemented that improves availability by bypassing a failure location and recovering a communication route when a failure occurs, and continues service to users.

  In the transmission protocol called MPLS-TP (MultiProtocol Label Switching-TransportProfile), which is being put into practical use by each telecommunications carrier, for the ATM (Asynchronous Transfer Mode) and Ethernet (registered trademark, the same applies hereinafter) signals accommodated, Provides a path for transmitting signals end-to-end. As its name suggests, MPLS-TP is a transmission protocol for the unified management of multiple transmission protocols (MultiProtocol) such as ATM and Ethernet, and it uses frame identifiers to identify frames. Perform switching. The MPLS-TP device is a device that can accommodate a plurality of types of signals in a mixed manner by giving a header signal indicating a destination called a label to a frame in accordance with several different international standards. The MPLS-TP device assigns a label to each signal and controls a switching transfer path.

  The MPLS-TP apparatus has a plurality of optical modules for transmitting and receiving frames, and can be set to output input signals from the plurality of optical modules according to the control of the label switch. Each optical module determines the maximum amount of frames that can be output per unit time, and it is not always possible to output all signals input from a plurality of optical modules without delay in one optical module. Therefore, the MPLS-TP device realizes a function of temporarily holding a frame that cannot be transmitted by the QoS function and a function of discarding depending on the type of the frame, thereby controlling the path quality. The QoS function sets the bandwidth for each path.

  In the MPLS-TP network, a physical redundancy configuration and a logical redundancy configuration are prepared in advance and switching is performed when a failure occurs. A high-quality path for communicating important data uses a redundant path prepared in advance to reduce the communication interruption time when a failure occurs to a scale of several tens of milliseconds. These high-quality paths consume physical and logical resources due to the redundancy of the transmission path, so that the communication carrier managing the transmission network provides the path at an expensive price. However, not all customers need such high-quality paths, and there is a limit to securing standby resources as network resources.

  For this reason, the telecommunications carrier provides a best-effort path with a non-redundant configuration as an inexpensive path according to customer needs. Since these paths do not have a redundant configuration, communication disconnection continues while a failure occurs. Although it is an expected event for a telecommunications carrier when a non-redundant path is provided in a contract with a customer, it is an expected event for a telecommunications carrier, but as a telecommunications carrier that provides telecommunications services to the customer. It is desirable to restore service as soon as possible.

  As a method for recovering from communication disconnection, Patent Document 1 uses an extra bandwidth and “suppresses the range for performing failure recovery control when switching to a substitute route at the failure end”. Change the setting to the device by calculating the detour route. Minimizing the range in which failure recovery control is performed in Patent Document 1 means that setting change operations on the apparatus are locally integrated.

JP 2005-175593 A

  In the method of Patent Document 1, since setting change operations for devices are locally integrated, processing necessary for setting a detour route is concentrated on a small number of devices constituting a new detour route. When the technology of Patent Document 1 is applied to an MPLS-TP network, local settings are made to a small number of communication devices that make up the MPLS-TP network, and the MPLS-TP label switch function and QoS (Quality of Service) ) Depending on the characteristics of the function, bottlenecks may occur in the device.

  When changing the path of a logical path to an MPLS-TP device, in order not to affect the existing path, the label switch function performs label duplication judgment, the QoS function performs interface card unit, optical module It is necessary to sequentially perform the consistency determination regarding the unit setting change. In this case, using the control CPU and memory built in the device, and the management built-in program, matching processing for the contents set in the label switch function and QoS function, and physical settings for each interface card and optical module The consistency check process after the change or setting change is performed, and a change time of several hundred milliseconds is required.

  Also, the label duplication determination and QoS bandwidth setting change time takes several hundred milliseconds to several seconds as the number of path settings (label usage and bandwidth usage) increases. For example, assuming that one device on a new detour route takes 0.5 to 2 seconds for label duplication determination and QoS bandwidth setting change for one path, for example, the same device is requested to determine 10,000 paths. It is estimated that it takes 5000 to 20000 seconds, that is, approximately 1 hour 23 minutes to 5 hours 33 minutes, and it takes a long time to restore the communication service.

  In order to solve the above problems, a network management apparatus according to the present invention provides a path management unit that manages a communication path of a path, and a command for requesting a communication apparatus on the communication path to perform processing necessary for changing the communication path. And a command management unit to be created. When the path management unit changes at least part of the communication paths of a plurality of paths to another communication path, at least one of the communication devices that need to be set to change the communication path has a plurality of commands for each path. The time required for the process is calculated, and it is determined whether or not the time required for processing the calculated commands exceeds a predetermined upper limit value.

  According to an embodiment of the present invention, when a failure occurs, the communication disconnection time of a path for which a redundant detour is not set in advance is reduced.

It is the figure which showed one Embodiment of the communication system. It is the figure which showed one structural example of the physical structure of a communication apparatus. It is a block diagram which shows one structural example of the physical structure and function of a network management apparatus. It is a block diagram which shows one structural example of the logical function structure of a network management apparatus. It is a figure which shows the example of 1 structure of an apparatus management table. It is a figure which shows the example of 1 structure of a path | pass management table. It is a figure which shows the example of 1 structure of a command management table. It is an example of a screen which the display control part of a network management apparatus provides. It is a figure explaining operation | movement in the communication apparatus at the time of a failure generation. It is a figure explaining the example of a setting of the detour of the communication network in which the failure generate | occur | produced. It is a flowchart which shows the procedure which calculates the detour path of embodiment of this invention.

  The following embodiments will be described with reference to the drawings. FIG. 1 is a diagram showing a communication system configuration of the present embodiment. The communication system configuration includes a communication device 10 corresponding to MPLS-TP, a communication network 20 that is an MPLS-TP network, a management network 30 for setting a path and its bandwidth to the plurality of communication devices 10, and a plurality of communication devices. 10 includes a network management device 40 that transmits a command to 10 to set a device state. The communication network 20 is composed of a plurality of communication devices 10. The communication device 10 is connected to the network management device 40 via the management network 30.

  The communication system of the present embodiment is connected to the external communication device 60-1 via the communication network 20, and transmits and receives a communication frame 50. The communication frame 50 is an electrical signal or an optical signal, and is transmitted to the communication device 10 via the communication network 20. The network management device 40 performs setting to transfer the communication frame 50 to each communication device 10 via the management network 30, and the communication frame 50 passes through each communication device 10 via the communication network 20 to perform external communication. Transferred to device 60-2. A setting unit of a route for transmitting a signal from the external communication device 60-1 to the external communication device 60-2 end-to-end is expressed as a path. Although FIG. 1 shows the connection of two external communication devices 60, the present invention can be applied to a configuration in which more external communication devices 60 are connected to the MPLS-TP network.

  In this embodiment, the transmission network of the external communication device 60-1 and the external communication device 60-2 is an Ethernet network, but may be a network of another protocol such as an ATM network. In this embodiment, when a failure of the communication device 10 occurs in the MPLS-TP network shown in FIG. 1, the network management device 40 that centrally manages the communication network 20 controls each communication device 10 via the management network 30. An embodiment for recovering a failure will be described.

  FIG. 2 is a diagram illustrating functional units inside the communication apparatus 10. The communication device 10 includes a frame processing unit 11, a management control unit 12, and a transfer control unit 13. The frame processing unit 11 is connected to a plurality of communication networks 20 and transmits / receives communication frames 50 to / from the communication network 20, and is connected to the transfer control unit 13 inside the communication device 10 to transmit / receive communication frames 50. The management control unit 12 is connected to the management network 30, transmits / receives communication from the network management device 40 shown in FIG. 1 via the management network 30, and is connected to the transfer control unit 13 inside the communication device 10. In response to a setting instruction (command) from the network management device 40, the command processing unit 14 sets the transfer control unit 13 in the device. The transfer control unit 13 is connected to the plurality of frame processing units 11 inside the communication device 10, and transmits / receives the communication frame 50 from the frame processing unit 11, and is also connected to the management control unit 12 inside the communication device 10, Settings such as to which frame processing unit 12 the 50 is transferred are received, and the connection between the frame processing units 11 is controlled.

  FIG. 3 is a diagram showing a physical configuration of the network management device 40. The physical configuration of the network management device 40 includes a central processing unit 41, a main storage device 42, a program 421 and data 422 stored in the main storage device 42, an auxiliary storage device 43, an external input / output interface 44, and a device communication interface 45. Consists of.

  The central processing unit 41 executes the program 421 of the main storage device 42 to realize various functions included in the program 421, and holds various data processed by the program 421 as data 422. The main storage device 42 records the calculation procedure used in the central processing unit 41 as a program 421, and also inputs the input from the external input / output interface 44, the input from the device communication interface, and the calculation result of the central processing unit 41 as data 422. To record. The auxiliary storage device 43 assists the recording of the program 421 and data 42 of the main storage device 42. The external input interface 44 acquires an input from a user who uses the network management apparatus by an input device such as a keyboard, a touch panel, or a voice input, and displays a calculation result of the central processing unit 41 on a display or the like. The device communication interface 45 converts the calculation result of the program 421 calculated by the central processing unit 41 into an electric signal and transmits / receives it to each communication device 10.

  FIG. 4 is a diagram showing a logical configuration, that is, a function of the network management device 40. The logical configuration of the network management device includes a display control unit 4211, a device management unit 4212, a connection management unit 4213, a path management unit 4214, a transfer management unit 4215, a command management unit 4216, an alive monitoring unit 4217, and a transmission / reception unit as a program 421. 4218.

  The display control unit 4211 provides necessary information to the administrator via a display device such as a display. The device management unit 4212 manages the state of each communication device 10. The path management unit 4214 manages a path that is a communication path formed between two communication devices 10 connected to different external communication devices 60, respectively. The transfer management unit 4215 determines a communication path between the communication devices 10 constituting the path.

  The command management unit 4216 manages commands that convey information to be set to the communication device 10 when setting a path or changing a communication path of a path. As described above, the communication device 10 that has received the command from the network management device 40 performs consistency processing of the contents set in the label switch function and the QoS function, and changes the physical settings in units of each interface card and in units of optical modules. Execute consistency check processing. The life and death monitoring unit 4217 receives failure information from each communication device 10 and prompts the device management unit 4212, the connection management unit 4213, and the path management unit 4214 to perform processing necessary for forming a detour.

  The data 422 includes a device management table 4221, a path management table 4223, and a command management table 4224. A configuration example of the device management table 4221 is shown in FIG. The device management table 4221 manages information related to the communication device 10 shown in FIG. The device management table 4221 includes a device ID 42221, a device name 42212, a recovery time upper limit value 42213, a failure state 42214, and a recovery time 42215. The device ID 42211 is identification information given to the communication device 10. Information for identifying a device on the network, such as an IP address or a MAC address, may be used as the device ID 42211. Alternatively, the device management unit 4211 may automatically register the device management table 4221 by assigning a device ID to the communication device 10 existing in the communication network 20. The device name 42212 is a name given to each communication device 10 so that the administrator can easily recognize it.

  The recovery time upper limit value 42213 is an upper limit value of the time taken to form a detour when another communication device 10 forms a detour when the communication device 10 fails. The recovery time upper limit value 42213 indicates the service type of the path accommodated by the communication device 10 (for example, whether it is a high-priced service or a low-priced service) and the type of application that the path accommodates (real-time processing such as video distribution is required) Or an application that does not require real-time performance such as mail or file download).

  The failure information 42214 holds failure information notified from the alive monitoring unit 4217 when a failure occurs. The transmission / reception unit 4218 receives the failure information from the communication device 10 and notifies the alive monitoring unit 4217 of the failure information. The alive monitoring unit 4217 notifies the failure information to the device management unit 4212, and the device management unit 4212 updates the failure information 42214 in the device management table 4221. The recovery time 42215 holds a value calculated by the path management unit 4214 when calculating the detour.

  FIG. 6 shows an example of the configuration of the path management table 4223. Here, referring to the example of FIG. 1, the path is a communication path formed between the external communication device 60-1 and the external communication device 60-2 that communicate with each other. This is a communication path formed between the communication device 10-1 connected to 60-1 and the communication device 10-2 connected to the external communication device 60-2.

  The path management table 4223 manages path information, which is a unit for setting a path for transmitting signals end-to-end as described above. The path management table 4223 includes a path ID 42231, a start point device 42232, an end point device 42233, and a path route 42235. The path ID 4231 is information for uniquely identifying the path, and each time a new path is formed, the path management unit 4214 attaches the path ID to the path and registers it in the path management table 4223. good. Referring to the example of FIG. 1, the start point device 42232 is the device name 42212 of the communication device 10-1 connected to the external communication device 60-1. Referring to the example of FIG. 1, the end point device 42233 is the device name 42212 of the communication device 10-2 connected to the external communication device 60-2. The path route 42235 is the device ID 42221 of the communication device 10 that forms the path. In the example of the path management table 4223 shown in FIG. 6, three paths are set between the NE1 communication device and the NE3 communication device via the NE2 communication device.

  One configuration example of the command management table 4224 is shown in FIG. The command management table 4224 manages information on commands transmitted from the network management device 40 to the communication device 10 when the communication device 10 shown in FIG. The command management table 4224 includes a command ID 42241, a command name 42242, and a response time 42243. The command ID 42241 is identification information for uniquely specifying a command that the network management device 40 transmits to each communication device. The command management unit 4216 may add a command ID to the currently registered command and automatically register it in the command management table 4224. The command name 42242 is a name of a command that can be easily identified by an administrator, for example, indicating what the command is for. The response time 42243 is the time required for processing the command transmitted by the communication device 10 when the network management device 40 issues a command to one communication device 10. For example, the response time 42243 can be obtained by actually measuring the time required for the communication apparatus 10 to process a command.

  FIG. 8 is a diagram illustrating an example of a screen controlled by the display control unit 4211. The screens controlled by the display control unit 4211 are a device management screen 42111, a path management screen 42113, and a command management screen 42114.

  The device management screen 42111 includes a field for inputting a device name 421111, a recovery time upper limit value 421112, and a registration button. The device name 42212 of the device management table 4221 stores the device name of the device name 421111, and the recovery time upper limit value 42213 of the device management table 4221 stores the recovery time upper limit value 421112. The display control unit 4211 notifies the user input of the device management screen 42111 to the device management unit 4212, and the device management unit 4212 registers the device name 4221 and the recovery time upper limit value 42212 of the device management table 4221 as such information.

  The path management screen 42113 includes a field for inputting a start point device connection 421131, an end point device connection 421132, a path band 421133, and a registration button. Information input to the start device connection 421131 is input to the start device 42232 of the path management table 4223, information input to the end device 421132 is input to the end device 42233 of the table, and the path bandwidth 421133 is input to the path bandwidth 42234 of the table. The information entered in is registered respectively.

  The command management screen 42114 includes a field for inputting a command name 421141, a response time 421142, and a registration button. The command name 42242 of the command management table 4224 stores information input to the command name 421141, and the response time 42243 of the table stores information input to the response time 421142.

  In the screen example for inputting such information, after the information is input, the information input by the administrator pressing the registration button is input to the network management device 40 via the external input / output interface 44, and is stored in the main storage device 42. Registered in each table. 4 will be described. The display control unit 4211 notifies the device management unit 4212 of the user input on the input screen of FIG. 8, and the device management unit 4212 registers the information in each table. Information registration in the device management table 4221 and the command management table 4224 by the device management screen 42111 and the command management screen 42114 is performed at an appropriate timing.

  FIG. 9 is a diagram showing the operation of the network management device 40 when a failure occurs. When a failure occurs in the communication device 10 located on the path of a certain path, the transmission / reception unit 4218 receives the failure information (9000). The transmission / reception unit 4218 notifies the failure information to the life and death monitoring unit 4217 (9001). The alive monitoring unit 4217 notifies the failure information to the path management unit 4214 (9002). The path management unit 4214 searches the device management table 4221 using the device ID 42221 included in the failure information as a key (9003), and acquires information such as the device name 42212 of the device in which the failure has occurred (9004). At this time, the path management unit 4214 changes the failure information 42214 of the failed device from “no problem” to “problem”.

  The path management unit 4214 determines and acquires path information passing through the identified faulty device from the path path 42235 of the path management table 4223 (9005, 9006). Specifically, since the path management unit 4214 has acquired the device name 42212 of the device in which the failure has occurred, the path management unit 4214 searches the path route 42234 with the device name and acquires the path ID 42231 of the path including the failed device. Then, the path management unit 4214 calculates detour paths for all paths that have acquired the path ID 42231.

  The path management unit 4214 acquires all command information from the command management table 4224 for use as a determination condition for calculating a detour route (9007, 9008). The path management unit 4214 executes detour route calculation for all paths based on the acquired information (9009). Details of the detour route determination procedure will be described with reference to FIG. The path management unit 4214 performs detour path route setting to the transfer control unit 4215 based on the determined detour path route (9010). The transfer control unit 4125 calculates a transfer setting command, and sets the transfer path to each communication device 10 on the detour path via the transmission / reception unit 4218 (9011, 9012, 9013, 9014, 9015). The path management unit 4214 updates the path management table 4223 based on the detour path route (9016, 9017, 9018). Specifically, the path route 42234 is updated using the device name 42212 on the detour path.

  The procedure for determining a bypass path will be described by taking the network configuration shown in FIG. 10 as an example. The network of FIG. 10 describes the communication network 20 of FIG. 1 in detail. In FIG. 10, 4000 paths from paths 42233-1 to 4000 are indicated by thick solid lines, and it is assumed that a failure has occurred in the communication device 10-13 on the path of these paths. As a precondition, the upper limit of the recovery time of each communication device is 1 hour. It is assumed that the command processing of the path change operation requires a processing time of 1 second in each communication device. Under this precondition, one communication device can process up to 3600 seconds, that is, 3600 commands.

  FIG. 11 is a flowchart for explaining processing of the network management device 40 that has received the failure information from the communication device 10-13. All processing is executed by the path management unit 4222. The path management unit 4222 determines path information passing through the communication device 10-13 identified from the failure information from the path route 4235 of the path management table 4223 (S-1001). In this case, since paths 42233-1 to 4000 exist (Y in S-1002), the path management unit determines a detour for the path (S-1003).

  A general route search method (depth-first search, width-first search, Dijkstra method, A * method) can be used as a route search method for a detour. For example, when the communication device 10-13 in which the failure has occurred in the example of FIG. 10 is removed from the path route and a detour is searched between the communication device 10-12 and the communication device 10-18, the communication that becomes these two end points is performed. The connection of the communication devices 10 that connect the devices 10 is calculated, and finally one communication path is determined. At this time, the detour may be determined in consideration of the bandwidth of each path included in the path 42231 and the communication bandwidth of the link (connection) between the communication devices 10.

  When the detour is determined, the path management unit 4222 calculates the time required for the restoration work of the communication device 10 existing on the detour (S-1004). The path management unit determines a command to be used for the detour path operation, and calculates the recovery time of each device using the response time 42243 of the command management table 4224 and the recovery time 42215 of the device management table 4221. For the command to be used, the setting to be changed is calculated from the detour information for the command to change the route.

  For example, when the communication devices 10-12, 10-17, and 10-18 are calculated by the route search method as a route that bypasses the path passing through the communication devices 10-12, 10-13, and 10-18, The network management device 40 issues a command to the communication device 10-12 to change the transfer setting from the communication device 10-12 to the communication device 10-13 to the setting to transfer from the communication device 10-12 to the communication device 10-17. It is generated and transmitted to the communication device 10-12. In addition, the communication device 10-17 generates a command for setting transfer of the frame received from the communication device 10-12 to the communication device 10-18, and transmits the command to the communication device 10-17. In addition, a command for changing the setting transferred from the communication device 10-13 to the setting transferred from the communication device 10-17 is generated for the communication device 10-18, and is transmitted to the communication device 10-18.

  When there are a plurality of communication devices 10 that need to change the route setting on the detour, the command processing time required for recovery of the path is calculated for each communication device 10. For example, when the communication devices 10-12, 10-17, and 10-18 are calculated by the route search method as a route that bypasses the path passing through the communication devices 10-12, 10-13, and 10-18, A command processing time for recovery of the communication devices 10-12, 10-17, and 10-18 is calculated.

  The path management unit 4222 adds the recovery times calculated for a plurality of paths for each communication device, and calculates the total recovery time of the plurality of paths (S-1005). This is because a plurality of paths need to be individually changed, and the network management apparatus 40 transmits a command for changing the path for each path to the communication apparatus 10 that requires a path change process on the detour.

  The path management unit 4222 determines, for each communication device 10, whether or not the calculated total recovery time exceeds the recovery time upper limit value 4213 of the device management table (S-1006). If not exceeded, the path management unit 4222 adopts the detour determined in S-1003 (S-1007). If there is a path that has not been relieved, a process for determining a detour is performed in the same manner for the unrelieved path. When there are no unrelieved paths, the path management unit 4222 ends the process of determining a detour and instructs the transfer management unit to transmit a command (S-1008).

  When the processing from S-1003 to S-1007 is applied to the network shown in FIG. Assume that a detour route 42251 that passes through the communication device 10-12, the communication device 10-17, and the communication device 10-23 is found as a detour route of the first path 42231-1 (shown by a dotted line). The communication band that can be accommodated in the detour route 42251 is large, and the path 42231-3600 up to the 3600th can be accommodated in the detour route 42251 (S-1003). The path management unit 4222 sets the response time of each of the communication device 10-12, the communication device 10-17, and the communication device 10-18 for the command with the command name “change transfer setting” indicated by the path ID 42241-1 in the command management table 4224. Estimated as 1000 ms registered in the response time 42243, that is, 1 second (S-1004). Next, the path management unit 4222 adds this 1 second to the time required to restore the path up to the third 3599, 3599 × 1000ms = 3599 seconds, and it is necessary to change the path of all 3600 paths in each communication device. The total recovery time is calculated as 3600 seconds (S-1005).

  The path management unit 4222 compares the calculated 3600 seconds with the time registered in the recovery time upper limit value 42213 of the device management table 4221. If the upper limit of the recovery time of the communication device 10 is 1 hour (3600 seconds) as shown in FIG. 5, the path management unit bypasses the path 42231-3600 because the calculated time does not exceed the time registered in the table. A communication path 42251 is adopted as the path, and a new path 42251-3600 is set.

  Next, for the path 42231-3601, the total recovery time in the same detour 42251 is calculated as 3600 + 1 = 3601 seconds, which exceeds 3600 seconds registered in the table. Returning to -1003, a different detour from the detour 42251 is searched. The search for another alternative route can also use the general route search method described above, and the alternative route may be determined in consideration of the bandwidth that can be accommodated by the path.

  Here, as a detour for path 42231-3601, communication device 10-7, communication device 10-6, communication device 10-11, communication device 10-16, communication device 10-21, communication device 10-22, communication device 10- Suppose that a detour 42261 via 23 is found (illustrated by a dotted line). It is assumed that the detour 42261 has a large band that can be accommodated, and all the remaining 400 paths 42231-3601 to 4000 of the path 42231 can be accommodated. In this case, in S-1002, there is no path to be relieved at the time of failure of the communication device 10-13, and the path management unit 4222 manages transfer of the determined alternative paths 42231-1 to 3600 and 42251-3601 to 4000. The command is sent to the unit 4215, and the command is transmitted from the transfer management unit 4215 to the communication device 10 that needs to set the route on each detour path (S-1008).

  In this embodiment, in a communication system including a plurality of communication devices and a network management device connected to each of the communication devices, each communication device constitutes a mesh network and is set in the mesh network Includes paths. A communication network management device includes a processor, a memory, and an interface, and includes information for identifying the communication device, information for identifying a working path group, information indicating a plurality of communication devices through which the working path group passes, and a communication device The information for identifying the command for operating, the information indicating the failure of the communication device, and the information indicating the recovery time allowed by the communication device are held in the memory. When it is necessary to calculate a detour route for the working path group based on the failure information and information of a plurality of communication apparatuses through which the working path group passes, the working path group having the adjacent communication apparatus as the start point and the end point is detoured. The path is determined, and it is determined whether the command processing time is within the recovery time range.

  As a result of the determination, when it is determined that the processing time of the command exceeds the recovery time, a path that bypasses the working path group starting from another communication device as a start point and an end point is determined, and the above determination process is performed as a working target to be bypassed. Repeat until there are no more paths or there are no more circuit candidates. Thereby, the setting reflection time is shortened by distributing each setting time to the communication device, or a detour route satisfying the time restriction set by the user is determined, and the communication disconnection time is reduced.

  According to the present embodiment, by calculating a detour route in consideration of the command response time, the recovery time is kept within the user's request time by distributing the set time required for changing the route of each communication device. Is possible.

10 Communication equipment
20 Communication network
30 Management network
40 Network management device
4212 Device Management Department
4214 Path Management Department
4215 Transfer Manager
4216 Command Management Department
4217 Life and death monitoring department
4218 transceiver
4221 Device management table
4223 Path management table
4224 Command management table
50 communication frames
60 External communication device

Claims (5)

A path management unit for managing the communication path of the path;
A command management unit that creates a command for requesting a communication device on the communication path for processing necessary for changing the communication path for each of the paths;
The path management unit
When changing at least some of the communication paths of a plurality of paths to another communication path, at least one of the communication devices that need to be set to change the communication path is required to process a plurality of commands for each path. Calculate the time,
A network management device for determining whether or not a time required for processing the calculated commands does not exceed a predetermined upper limit value. The network management device according to claim 1,
The path management unit
When the time required for processing the calculated command does not exceed the predetermined upper limit, the new communication path is adopted,
A network management device, wherein when the time required for processing the calculated command exceeds the predetermined upper limit value, another network path is searched for in place of the other path. The network management device according to claim 1,
When there are a plurality of communication devices that need to be set to change the communication path, the path management unit adds the time required for processing the command for each path to each of the communication devices, and communicates a plurality of paths. A network management apparatus characterized in that a processing time of the command required for changing a route is calculated and compared with the predetermined upper limit value. The network management device according to claim 1,
A network management apparatus comprising a command management table for storing a time required for processing of each command by the communication apparatus in association with each of a plurality of command types. The network management device according to claim 1,
A network management device, comprising: a device management table for storing the upper limit value, which is a time allowed for processing the command, for each communication device.

Images