JP7624838B2 - Communication Equipment - Google Patents

Description

This disclosure relates to a communication device.

A large-scale communication device may be installed in a base station. The communication device contains multiple control units. One of the multiple control units operates as the control unit for the current system. The other control units are prepared as control units for the backup system. Within the communication device, the normality of the transmission path, the inside of the control unit, the interfaces, etc. is periodically monitored. If a fault is detected within the communication device, operation is switched.

Here, a technology has been proposed to prevent false fault detection due to momentary noise, etc. (see Patent Document 1). In Patent Document 1, when a fault is detected, a counter value is counted up. When the counter value matches a recognition setting value, a new fault is recognized. In this way, when faults are continuously detected, a new fault is recognized.

JP 2001-125807 A

With the above technology, if a failure continues to be detected, a new failure is recognized. When the above technology is used, many frames are lost until the new failure is recognized and operation switching is initiated. For this reason, it is not advisable to use only the above technology.

The goal of this disclosure is to prevent too many frames from being lost.

A communication device according to an aspect of the present disclosure is provided. The communication device transmits and receives frames. The communication device has a storage unit that periodically stores failure management information, which is information indicating whether or not one or more failures have been detected in each of a plurality of groups, and a failure control unit that determines that a failure has occurred when one or more failures have been detected in two or more groups out of the plurality of groups based on the failure management information, and when the total sum of the number of the one or more failures and the number of failures detected after the one or more failures have been detected is greater than a preset threshold . Each of the plurality of groups indicates a function of the communication device, a component of the communication device, or an interface between components of the communication device, which is a monitoring target.

This disclosure makes it possible to prevent many frames from being lost.

FIG. 1 is a diagram showing a communication system according to a first embodiment. 2 is a diagram illustrating hardware included in a frame control unit according to the first embodiment. 4 is a block diagram showing the functions of a frame control unit according to the first embodiment; FIG. FIG. 2 is a diagram illustrating an example of a failure management table according to the first embodiment; 10 is a flowchart illustrating an example of a process executed by a frame control unit according to the first embodiment. A block diagram showing the functions of a frame control unit in embodiment 2. 13 is a flowchart (part 1) illustrating an example of processing executed by a frame control unit according to the second embodiment. 13 is a flowchart (part 2) illustrating an example of processing executed by a frame control unit according to the second embodiment.

The following describes an embodiment with reference to the drawings. The following embodiment is merely an example, and various modifications are possible within the scope of this disclosure.

Embodiment 1.
1 is a diagram showing a communication system according to a first embodiment. The communication system includes a communication device 10 and a communication device 20. For example, the communication device 10 and the communication device 20 are connected to each other via a cable. The communication device 10 is also connected to a higher-level NW (Network) 30.

The communication device 10 is also called a parent device. The communication device 20 is also called a child device. For example, if the communication system is an optical communication system, the communication device 10 may be considered as an OLT (Optical Line Terminal). The communication device 20 may be considered as an ONU (Optical Network Unit).

The communication device 10 transmits and receives frames. Specifically, the communication device 10 transmits frames communicated between the communication device 20 and the upper network 30. The communication device 10 has a frame control unit 100, a frame control unit 200, and transmission path switching units 11 and 12.

The frame control units 100 and 200 may be called control units or frame control devices. For example, the frame control unit 100 is the frame control unit of the current system. When the frame control unit 100 is the frame control unit of the current system, the frame control unit 200 is the frame control unit of the backup system. When a fault is detected in the communication device 10, the operation is switched in the communication device 10. When the operation is switched, the frame control unit 200 is operated as the frame control unit of the current system. In the following description, it is assumed that the frame control unit 100 is the frame control unit of the current system.

The frame control units 100 and 200 perform a preset process on the frame. For example, the frame control units 100 and 200 check the normality of the frame.
The transmission path switching units 11 and 12 may be called transmission path switching devices. The transmission path switching units 11 and 12 switch the transmission path of a frame in response to an instruction from the frame control unit 100 or the frame control unit 200. The number of transmission path switching units is not limited to two.

Next, the hardware of the frame control unit 100 will be described.
2 is a diagram showing hardware included in the frame control unit of embodiment 1. The frame control unit 100 includes a processor 101, a volatile storage device 102, and a non-volatile storage device 103. This sentence may be read as follows: The communication device 10 includes the processor 101, the volatile storage device 102, and the non-volatile storage device 103.

The processor 101 controls the entire frame control unit 100. For example, the processor 101 is a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), or the like. The processor 101 may be a multiprocessor. The frame control unit 100 may have a processing circuit. The processing circuit may be a single circuit or a composite circuit.

The volatile storage device 102 is a main storage device of the frame control unit 100. For example, the volatile storage device 102 is a random access memory (RAM). The non-volatile storage device 103 is an auxiliary storage device of the frame control unit 100. For example, the non-volatile storage device 103 is a hard disk drive (HDD) or a solid state drive (SSD).
Similarly, the frame control unit 200 includes a processor, a volatile storage device, and a non-volatile storage device. The frame control unit 200 may include a processing circuit.

Next, the functions of the frame control unit 100 will be described.
3 is a block diagram showing functions of the frame control unit according to the first embodiment. The frame control unit 100 includes a storage unit 110, frame processing units 120_1 and 120_2, a power supply unit 130, fault monitoring units 140_1, 140_2, ..., 140_n, a registration unit 150, a fault control unit 160, and a switching control unit 170. Here, the frame processing units 120_1 and 120_2 are collectively referred to as the frame processing unit 120. The fault monitoring units 140_1, 140_2, ..., 140_n are collectively referred to as the fault monitoring unit 140.

The storage unit 110 may be realized as a storage area secured in the volatile storage device 102 or the non-volatile storage device 103 .
Some or all of the frame processing unit 120, power supply unit 130, fault monitoring unit 140, registration unit 150, fault control unit 160, and switching control unit 170 may be realized by a processing circuit. Also, some or all of the frame processing unit 120, power supply unit 130, fault monitoring unit 140, registration unit 150, fault control unit 160, and switching control unit 170 may be realized as program modules executed by the processor 101.

The storage unit 110 stores a failure management table, which will be described later.
The frame processing unit 120 performs a preset process on a frame received from the communication device 20 or the upper NW 30 .
The power supply unit 130 supplies power to drive the frame control unit 100 .

The fault monitor 140 performs monitoring. The function of the fault monitor 140 will be described in detail later.
The registration unit 150 periodically obtains information indicating whether or not a failure has been detected from the failure monitor 140. The registration unit 150 registers the information in a failure management table. The failure management table will now be described.

4 is a diagram showing an example of a failure management table according to the embodiment 1. The failure management table 111 is stored in the storage unit 110. The failure management table 111 is also referred to as failure management information.
The vertical axis of the failure management table 111 indicates time. The horizontal axis of the failure management table 111 indicates the name of the failure monitor 140. For example, the failure monitor A in Fig. 4 may be considered as the failure monitor 140_1. The failure monitor B in Fig. 4 may be considered as the failure monitor 140_2.

The fault management table 111 indicates multiple groups. The groups may be called monitoring targets, monitoring target groups, or fault groups. The fault management table 111 is information indicating whether or not a fault has been detected in each of the multiple groups. In detail, the fault management table 111 periodically indicates whether or not one or more faults have been detected in each of the multiple groups. The multiple groups are monitored by multiple fault monitoring units.

Each of the multiple groups indicates a function of the communication device 10, a component of the communication device 10, or an interface between components of the communication device 10 that is to be monitored. This sentence may also be expressed as follows: Each of the multiple groups indicates one of a function of the communication device 10, a component of the communication device 10, or an interface between components of the communication device 10 that is to be monitored.

For example, all of groups 1 to 3 may indicate functions possessed by the communication device 10. All of groups 1 to 3 may indicate components possessed by the communication device 10. All of groups 1 to 3 may indicate interfaces between components possessed by the communication device 10. Furthermore, each of groups 1 to 3 may be a different monitoring target. For example, group 1 indicates functions possessed by the communication device 10, group 2 indicates components possessed by the communication device 10, and group 3 indicates interfaces between components possessed by the communication device 10.

Here, the functions of the communication device 10 will be specifically described. For example, the function of the communication device 10 is a function to check the normality of a frame. The function to check the normality of a frame is realized by the frame processing unit 120. For example, the frame processing unit 120 checks the normality of a frame using a checksum. The check may be considered to be performed by the frame processing unit 120_1. Also, for example, the frame processing unit 120 checks whether the size of the frame is normal. The check may be considered to be performed by the frame processing unit 120_2. When the above example is applied to group 1 in FIG. 4, group 1 shows a function to check the normality of a frame. The fault monitoring unit A (for example, the fault monitoring unit 140_1) monitors the frame processing unit 120_1. If the frame processing unit 120_1 is not operating normally, the fault monitoring unit A notifies the registration unit 150 that a fault has been detected. The registration unit 150 registers information indicating that a fault has been detected in the fault management table 111. Furthermore, fault monitoring unit B (for example, fault monitoring unit 140_2) monitors frame processing unit 120_2. If frame processing unit 120_2 is not operating normally, fault monitoring unit B notifies registration unit 150 that a fault has been detected. Registration unit 150 registers information indicating that a fault has been detected in fault management table 111.

Next, the components of the communication device 10 will be specifically described. The components are the processor 101, the volatile storage device 102, the non-volatile storage device 103, and a power supply IC (Integrated Circuit). For example, if all of groups 1 to 3 indicate components of the communication device 10, group 1 is the processor 101, group 2 is the volatile storage device 102, and group 3 is the power supply IC. If group 1 is the processor 101, the fault monitoring unit A monitors a certain block (e.g., a circuit) in the processor 101. If the block is not operating normally, the fault monitoring unit A notifies the registration unit 150 that a fault has been detected. The registration unit 150 registers information indicating that a fault has been detected in the fault management table 111. If group 1 is the processor 101, the fault monitoring unit B monitors other blocks in the processor 101. If the other blocks are not operating normally, the fault monitoring unit B notifies the registration unit 150 that a fault has been detected. The registration unit 150 registers information indicating that a fault has been detected in the fault management table 111. In this way, each of the multiple fault monitoring units monitors a different location within one component. Then, when a fault is detected, the fact that a fault has been detected is registered in the fault management table 111.

Finally, the interfaces between the components of the communication device 10 will be specifically described. For example, the interfaces are the interface between the transmission line switching unit 11 and the frame control unit 100, the interface between the transmission line switching unit 12 and the frame control unit 100, and the like. For example, group 1 indicates the interface between the transmission line switching unit 11 and the frame control unit 100. Also, for example, group 2 indicates the interface between the transmission line switching unit 12 and the frame control unit 100. For example, when group 1 indicates the interface between the transmission line switching unit 11 and the frame control unit 100, the normality of the interface is monitored by the fault monitoring unit A or the fault monitoring unit B. In other words, when group 1 indicates the interface between the transmission line switching unit 11 and the frame control unit 100, the fault monitoring unit A or the fault monitoring unit B monitors whether the communication between the transmission line switching unit 11 and the frame control unit 100 is normal. If it is not normal, the fact that a fault has been detected is registered in the fault management table 111.

Figure 4 shows that one group (i.e., the monitoring target) is monitored by two fault monitoring units. One group may be monitored by one fault monitoring unit. Also, one group may be monitored by three or more fault monitoring units.

As described above, the registration unit 150 periodically registers information indicating whether or not a failure has been detected in the failure management table 111. For example, the registration unit 150 registers in the failure management table 111 that the failure monitoring units A to F have not detected a failure at time _t0 . Also, for example, the registration unit 150 registers in the failure management table 111 that the failure monitoring units A and B have detected a failure at time _t1 . Then, the registration unit 150 registers in the failure management table 111 that the failure monitoring units C to F have not detected a failure at time _t1 .

Returning to FIG. 3, the function of the fault control unit 160 will be described.
The fault control unit 160 determines that a fault has occurred when a fault is detected in one of groups 1 to 3 and the fault continues to be detected in the single group for a preset time (hereinafter referred to as the threshold time) based on the fault management table 111. The fault control unit 160 also determines that a fault has occurred when a fault is detected in all of groups 1 to 3 based on the fault management table 111.

A specific description will be given with reference to FIG. 4. The fault control unit 160 determines that a fault has been detected in a single group at time _t1 based on the fault management table 111. The fault control unit 160 judges the fault to be an instantaneous fault. The fault control unit 160 then treats the fault as an instantaneous fault. Note that instantaneous faults include noise superimposed on a transmission path and soft errors caused by cosmic rays. The fault control unit 160 determines that a fault has been continuously detected in the single group for a threshold time. That is, the fault control unit 160 determines that a fault has been detected at times _t2 and _t3 . As a result, the fault control unit 160 determines that a fault has occurred. When it is determined that a fault has occurred, the fault control unit 160 executes a warning output process. For example, the fault control unit 160 performs control so that a sound indicating a warning is output from a speaker. Also, for example, the fault control unit 160 outputs information indicating a warning to an external device. Note that the speaker and the external device are not illustrated.

On the other hand, the fault control unit 160 determines, based on the fault management table 111, that faults have been detected in multiple groups at time t _n+1 . The fault control unit 160 determines that the fault is a continuous fault. Then, the fault control unit 160 treats the fault as a continuous fault. The fault control unit 160 determines that a fault has occurred. The fault control unit 160 executes a warning output process. Note that, when faults are detected in multiple groups, there is a high possibility that the faults will occur in a chain reaction in other groups. Therefore, the fault control unit 160 immediately determines that a fault has occurred. Here, the multiple groups may be called groups in which a chain reaction of faults occurs.

Here, an example of a chain of failures will be described. In one group, a failure in the power supply unit 130 is detected. When a failure occurs in the power supply unit 130, power is no longer supplied to the frame processing unit 120 and other components. When the supply of power stops, the operation of the frame processing unit 120 and other components stops. When the operation of the frame processing unit 120 and other components stops, a failure in the frame processing unit 120 and other components is detected. In this way, a chain of failures occurs.

As an example of a continuous failure, the failure control unit 160 determines that a failure has occurred when failures are detected in all of groups 1 to 3. However, the failure control unit 160 may also determine that a failure has occurred when failures are detected in two or more groups (for example, groups 1 and 2) among groups 1 to 3.
Furthermore, when it is determined that a fault has occurred, the fault control unit 160 may transmit an instruction to the source of the frame to stop transmitting the frame, thereby preventing many frames from being lost.

When it is determined that a failure has occurred, the switching control unit 170 controls one or more transmission path switching units so that the frame control unit 200 receives frames. This sentence may also be expressed as follows: When it is determined that a failure has occurred, the switching control unit 170 controls the transmission path switching units 11 and 12 so that the frame control unit 200 transmits and receives frames. For example, the switching control unit 170 transmits a transmission path switching instruction to the transmission path switching units 11 and 12. As a result, the transmission path switching units 11 and 12 switch the transmission path so that the frame is received by the frame control unit 200.

Next, the process executed by the frame control unit 100 will be described with reference to a flowchart.
5 is a flowchart showing an example of processing executed by the frame control unit according to embodiment 1. The frame control unit 100 executes the processing of FIG.

(Step S<b>11 ) The failure control unit 160 refers to the failure management table 111 .
(Step S12) The fault controller 160 determines whether or not a fault has been detected. If a fault has been detected, the process proceeds to step S13. If no fault has been detected, the process proceeds to step S15.

(Step S13) The fault control unit 160 determines whether or not a fault has been detected in a single group. If a fault has been detected in a single group, the process proceeds to step S14. If faults have been detected in multiple groups, the process proceeds to step S16.

(Step S14) The fault control unit 160 refers to the fault management table 111 and determines whether or not a fault has been continuously detected in a single group for a threshold time. In detail, the fault control unit 160 refers to past information based on the current time and determines whether or not a fault has been continuously detected in a single group for a threshold time. If the condition is met, the process proceeds to step S16. If the condition is not met, the process proceeds to step S15.
(Step S15) The fault control unit 160 waits for a period of time. The period of time is the period of time during which information is registered in the fault management table 111. After the period of time has elapsed, step S11 is executed.
(Step S16) The fault control unit 160 determines that a fault has occurred and executes a process of outputting a warning.
(Step S17) The switching control unit 170 executes a switching process.

According to the first embodiment, the communication device 10 quickly determines whether the failure is momentary or continuous based on the failure management table 111. In this way, the communication device 10 can prevent many frames from being lost by quickly determining the type of failure.

The fault control unit 160 may execute the following process. In the case of No in step S13, if the sum of the number of faults detected at each time is greater than a preset threshold (hereinafter referred to as the threshold number), the fault control unit 160 executes the process of step S15. The process will be described with reference to FIG. 4. First, the threshold number is set to 5. The fault control unit 160 determines that the number of faults detected at time t _n+1 is 3. Since 3 is smaller than 5, the fault control unit 160 does not determine that a fault has occurred. The fault control unit 160 determines that the number of faults detected at time t _n+2 is 4. The sum is 7. Since 7 is greater than 5, the fault control unit 160 determines that a fault has occurred. Then, the fault control unit 160 executes a warning output process.

In this way, if one or more faults are detected in two or more of the multiple groups (i.e., if step S13 is No), and if the sum of the number of the one or more faults and the number of faults detected after the one or more faults are detected is greater than the threshold number, the fault control unit 160 determines that a fault has occurred. This process prevents the fault control unit 160 from immediately determining that a fault has occurred. This allows the communication device 10 to carefully consider whether a fault has occurred. Therefore, the communication device 10 can achieve highly accurate fault determination.

In addition, each of the multiple groups may be associated with a priority. For example, the group with the highest priority may be considered as follows. When a fault is detected in the group with the highest priority, the group is a group in which it may be determined that a fault has occurred without waiting for multiple faults to be detected in the group. In step S13, the fault control unit 160 may execute the following process. When a fault has been detected in a single group and the single group has the highest priority among the multiple groups, the fault control unit 160 executes the process of step S15. That is, the fault control unit 160 determines that a fault has occurred. Then, the fault control unit 160 executes a warning output process.

As described above, if a failure is detected in the group with the highest priority, it can be said that a failure has clearly occurred. Therefore, when a failure is detected in the group with the highest priority, the communication device 10 immediately determines that a failure has occurred. Therefore, the communication device 10 can prevent many frames from being lost.

Furthermore, each of the multiple fault monitoring units may be associated with a priority. For example, the fault monitoring unit with the highest priority may be considered as follows. When the fault monitoring unit with the highest priority detects a fault, it may be immediately determined that a fault has occurred. In step S13, the fault control unit 160 may execute the following process. When a fault has been detected in a single group and the fault monitoring unit that detected the fault has the highest priority among the multiple fault monitoring units, the fault control unit 160 executes the process of step S15. That is, the fault control unit 160 determines that a fault has occurred. Then, the fault control unit 160 executes a warning output process.

Here, if the fault monitoring unit with the highest priority detects a fault, it can be said that a fault has clearly occurred. Therefore, when the fault monitoring unit with the highest priority detects a fault, the communication device 10 immediately determines that a fault has occurred. Therefore, the communication device 10 can prevent many frames from being lost.

The frame control unit 200 may include a storage unit 110 , a frame processing unit 120 , a power supply unit 130 , a fault monitoring unit 140 , a registration unit 150 , a fault control unit 160 , and a switching control unit 170 .
3 illustrates a case in which frame control unit 100 includes storage unit 110, fault monitoring unit 140, registration unit 150, fault control unit 160, and switching control unit 170. However, storage unit 110, fault monitoring unit 140, registration unit 150, fault control unit 160, and switching control unit 170 may be realized outside frame control unit 100 in communication device 10, or by other devices in communication device 10.

1 shows that the frame control unit is configured redundantly. However, other functional units or devices may be configured redundantly. The process described in the first embodiment may be executed in the communication device 10 including the other functional units or devices.
In the first embodiment, when it is determined that a fault has occurred, a warning is output and a switching process is executed. The first embodiment is also applicable to a device that does not have a switching control unit 170. For example, when the fault control unit 160 of the device determines that a fault has occurred, the fault control unit 160 transmits a frame transmission stop instruction to the frame transmission source. This prevents many frames from being lost.

Embodiment 2.
Next, a second embodiment will be described. In the second embodiment, differences from the first embodiment will be mainly described. Furthermore, in the second embodiment, description of the commonalities with the first embodiment will be omitted. In the first embodiment, if a fault is continuously detected in a single group for a threshold time, an alarm is output. However, some faults occur intermittently. In the first embodiment, if a fault occurs intermittently, an alarm is not output. Therefore, in the second embodiment, a case will be described in which a silent fault, which is a fault for which no alarm is output, is detected.

Fig. 6 is a block diagram showing the functions of a frame control unit according to embodiment 2. The components in Fig. 6 that are the same as those in Fig. 3 are given the same reference numerals as those in Fig. 3.
The frame control unit 100 further includes a counter unit 180. The counter unit 180 counts the number of instantaneous faults, which is the number of faults that occur intermittently in a single group. A new function is added to the fault control unit 160. This function will be described later.

Fig. 7 is a flowchart (part 1) showing an example of processing executed by the frame control unit of the second embodiment. The processing in Fig. 7 differs from the processing in Fig. 5 in that step S14a is executed. Therefore, step S14a will be described in Fig. 7. Descriptions of the processing other than step S14a will be omitted.
(Step S14a) The fault control unit 160 refers to the fault management table 111 and determines whether or not a fault has been continuously detected in a single group for a threshold time. If the condition is met, the process proceeds to step S16. If the condition is not met, the process proceeds to step S21.

FIG. 8 is a flowchart (part 2) illustrating an example of processing executed by the frame control unit according to the second embodiment.
(Step S21) The fault control unit 160 refers to the fault management table 111 and determines whether or not a fault was detected one cycle ago. If a fault was detected one cycle ago, the process proceeds to step S15. If a fault was not detected one cycle ago, the process proceeds to step S22.

(Step S22) The counter unit 180 counts up the number of instantaneous fault occurrences. The number of instantaneous fault occurrences is stored in the memory unit 110. The number of instantaneous fault occurrences exists for each group. Therefore, the number of instantaneous fault occurrences that is counted up is the number of instantaneous fault occurrences for the single group identified in step S13.

(Step S23) The fault control unit 160 determines whether the counted-up number of instantaneous fault occurrences is greater than a preset threshold. If the number of instantaneous fault occurrences is greater than the threshold, the process proceeds to step S16. If the number of instantaneous fault occurrences is equal to or less than the threshold, the process proceeds to step S15.

According to the second embodiment, the communication device 10 can detect a silent failure.
Furthermore, counter section 180 may be realized outside frame control section 100 in communication device 10 or in another device within communication device 10 .

The features of each of the embodiments described above can be combined as appropriate.

10 Communication device, 11, 12 Transmission line switching unit, 20 Communication device, 100, 200 Frame control unit, 101 Processor, 102 Volatile storage device, 103 Non-volatile storage device, 110 Storage unit, 111 Fault management table, 120, 120_1, 120_2 Frame processing unit, 130 Power supply unit, 140, 140_1, 140_2, ..., 140_n Fault monitoring unit, 150 Registration unit, 160 Fault control unit, 170 Switching control unit, 180 Counter unit.

Claims (8)

A communication device for transmitting and receiving frames,
a storage unit that periodically stores failure management information indicating whether or not one or more failures have been detected in each of a plurality of groups ;
a failure control unit that determines that a failure has occurred when one or more failures are detected in two or more of the plurality of groups or the plurality of groups based on the failure management information and when a total of the number of the one or more failures and the number of failures detected after the one or more failures are detected is greater than a preset threshold value ;
having
Each of the plurality of groups indicates a function of the communication device, a component of the communication device, or an interface between components of the communication device, which are targets of monitoring.
Communications equipment. the storage unit stores the failure management information, which is information indicating whether or not a failure has been detected in each of the plurality of groups;
the failure control unit determines that a failure has occurred when a failure is detected in a single group among the plurality of groups based on the failure management information, and the failure is continuously detected in the single group for a preset time after the failure is detected.
The communication device according to claim 1 . A communication device for transmitting and receiving frames,
a storage unit that stores failure management information that is information indicating whether or not a failure has been detected in each of a plurality of groups to which a priority is associated ;
a failure control unit that determines that a failure has occurred when a failure is detected in a single group among the plurality of groups based on the failure management information and the single group has the highest priority among the plurality of groups ;
having
Each of the plurality of groups indicates a function of the communication device, a component of the communication device, or an interface between components of the communication device, which are targets of monitoring.
Communications equipment. A communication device for transmitting and receiving frames,
a plurality of fault monitoring units each having a priority associated therewith and monitoring a plurality of groups;
a storage unit that stores failure management information that is information indicating whether or not a failure has been detected in each of a plurality of groups;
a registration unit that registers information indicating whether or not the plurality of fault monitoring units have detected a fault in the fault management information;
a fault control unit that determines that a fault has occurred when a fault is detected in one of the plurality of groups based on the fault management information and the priority of the fault monitoring unit that detected the fault is the highest among the plurality of fault monitoring units ;
having
Each of the plurality of groups indicates a function of the communication device, a component of the communication device, or an interface between components of the communication device, which are targets of monitoring.
Communications equipment. the failure control unit determines that a failure has occurred when a failure has been detected in all of the plurality of groups or in two or more of the plurality of groups based on the failure management information.
5. A communication device according to claim 3 or 4 . The fault control unit executes a warning output process when it is determined that a fault has occurred.
A communication device according to any one of claims 1 to 5 . one or more transmission path switching units for switching a transmission path of the frame;
a standby frame control unit capable of performing a preset process on the frame;
a switching control unit that controls the one or more transmission line switching units so that the frame control unit of the backup system receives the frame when it is determined that a failure has occurred;
Further comprising
A communication device according to any one of claims 1 to 6 . When it is determined that a failure has occurred, the failure control unit transmits an instruction to stop frame transmission to a source of the frame.
A communication device according to any one of claims 1 to 6.

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