JP6914804B2 - Communication device firmware update method, communication device control device and communication device - Google Patents

Description

The present invention relates to a method of updating firmware of a communication device, a control device of the communication device, and a communication device.

A communication device that mediates between the upper network and the lower network is known. In such a communication device, from the viewpoint of improving fault tolerance, a configuration in which at least one of the upper side and the lower side is made redundant has been proposed.

For example, Japanese Patent Application Laid-Open No. 2010-147801 (Patent Document 1) is a station-side device applied to PON (Passive Optical Network), which is a medium-sharing communication in which a plurality of home-side devices share a medium to transmit data. To disclose. This station-side device enhances fault tolerance by making a plurality of optical line units terminated on the station side redundant. Specifically, the station-side device includes one or a plurality of standby optical line units in addition to the operational optical line unit.

Japanese Unexamined Patent Publication No. 2010-147801

Generally, a communication device implements firmware for performing its function. In a communication device having an upper device and a lower device, it may be necessary to update the firmware of both the upper device and the lower device.

However, for example, in the case of a firmware update that involves a change in the interface between the upper side and the lower side, there is also a combination between the new upper side firmware and the old lower side firmware (conversely, the combination of the old upper side firmware and the new lower side firmware). Difficult to maintain compatibility in (possible). For this reason, it is conceivable that the new firmware becomes complicated or that communication is interrupted during the firmware update.

In the station-side device disclosed in Japanese Patent Application Laid-Open No. 2010-147801, the optical line unit, which is a lower device, is made redundant. On the other hand, the concentrator, which is a higher-level device, is not redundant. Therefore, Japanese Patent Application Laid-Open No. 2010-147801 does not disclose the above-mentioned problems and solutions thereof.

An object of the present invention is to update the firmware of the upper side and the lower side while continuing the communication service in the communication device having a redundant configuration on both the upper side and the lower side.

The method of updating the firmware of the communication device according to one aspect of the present invention is a plurality of redundant higher-level devices so as to be connected to a higher-level network via a plurality of physical links bundled in one or a plurality of logical links. This is a method of updating the firmware of a communication device configured to enable continuous communication by providing a plurality of lower devices that are redundant by alternative lower devices and can be connected to a lower line. A step of creating at least one higher-level device to which the lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, and a step of updating the firmware of at least one higher-level device to which the lower-level device is not connected. , The step of updating the firmware of the lower device is provided, and in the step of updating the firmware of the lower device, redundant switching and a compatible upper device are selected.

The control device according to one aspect of the present invention can be replaced with a plurality of redundant higher-level devices so as to be connected to a higher-level network via a plurality of physical links bundled in one or a plurality of logical links. A control device that controls a communication device that is redundant by a lower device and is configured to enable continuous communication by providing a plurality of lower devices that can be connected to a lower line. The control device is a lower device. A step of creating at least one higher-level device to which a lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, a step of updating the firmware of at least one higher-level device to which a lower-level device is not connected, and a lower-level device. A step of updating the firmware of a device and a step of updating the firmware of a lower device configured to perform include redundant switching and a step of selecting a compatible higher device.

The communication device according to one aspect of the present invention can be replaced with a plurality of redundant higher-level devices so as to be connected to a higher-level network via a plurality of physical links bundled in one or a plurality of logical links. It includes a plurality of lower-level devices that are made redundant by lower-level devices and can be connected to lower-level lines, and a control unit. The control unit aggregates the higher-level devices to which the lower-level devices are connected to create at least one higher-level device to which the lower-level device is not connected, and the firmware of at least one higher-level device to which the lower-level device is not connected. The step of updating, the step of updating the firmware of the lower device, and the step of updating the firmware of the lower device are configured to execute, and the step of updating the firmware of the lower device includes a step of redundant switching and selecting a compatible upper device.

According to the above, in a communication device having a redundant configuration on both the upper side and the lower side, it is possible to update the firmware on the upper side and the lower side while continuing the communication service.

It is a block diagram which showed the schematic structure of the communication apparatus which concerns on embodiment of this invention. FIG. 1 is a first diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 2 is a second diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 3 is a third diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 4 is a fourth diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 5 is a fifth diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 6 is a sixth diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 7 is a seventh diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 8 is a diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 9 is a ninth diagram showing a procedure in an example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 1 is a first diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 2 is a second diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 3 is a third diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 4 is a fourth diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 5 is a fifth diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 6 is a sixth diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. FIG. 7 is a diagram showing a procedure in another example of a method of updating firmware of a communication device according to an embodiment of the present invention. It is a block diagram for demonstrating the application example of the PON to the station side apparatus of the communication apparatus which concerns on embodiment of this invention.

[Explanation of Embodiments of the Present Invention]
First, embodiments of the present invention will be listed and described.

(1) A method of updating the firmware of a communication device according to one aspect of the present invention is redundant so as to be connected to an upper network via a plurality of physical links bundled in one or a plurality of logical links. A method of updating the firmware of a communication device configured to enable continuous communication by providing a plurality of lower devices that are redundant by a lower device that can be replaced and that can be connected to a lower line. There is a step of creating a higher-level device to which at least one lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, and a step of updating the firmware of the higher-level device to which the lower-level device is not connected. , The step of updating the firmware of the lower device is provided, and in the step of updating the firmware of the lower device, redundant switching and a compatible upper device are selected.

According to the above, in a communication device having a redundant configuration on both the upper side and the lower side, it is possible to update the firmware on the upper side and the lower side while continuing the communication service. By aggregating the higher-level devices to which the lower-level devices are connected, at least one higher-level device to which the lower-level devices are not connected is created. Update the firmware of the host device. At this point, the firmware of at least one higher-level device is new (updated) firmware, and the firmware of the other at least one higher-level device is old (unupdated) firmware. On the other hand, since the firmware of all the lower devices is the firmware before the update, all the lower devices are not connected to the upper device in which the new firmware is installed. The lower device updates its own firmware. In the step of updating the firmware of the lower device, select a higher device that is compatible with redundant switching. As a result, it is possible to avoid the influence on the continuation of the communication service due to the difference in the firmware version between the upper device and the lower device. Therefore, the firmware can be updated while the communication service is continued.

(2) Preferably, the plurality of lower-level devices is larger than the plurality of higher-level devices. The step of updating the firmware of the higher-level device is a step of updating the firmware of a part of the higher-level devices among the plurality of higher-level devices to prepare a higher-level device whose firmware has been updated and a higher-level device whose firmware has not been updated. And, the step of disconnecting the lower device whose firmware has not been updated from the higher device which has not been updated, the step of updating the firmware of the lower device which has not been updated, and the step of connecting the lower device whose firmware has been updated to the higher device which has been updated. Includes steps to do.

According to the above, after updating the firmware of the lower device, it is possible to avoid the influence on the continuation of the communication service due to the difference in the firmware version between the higher device and the lower device.

(3) The control device according to one aspect of the present invention includes a plurality of redundant higher-level devices so as to be connected to a higher-level network via a plurality of physical links bundled in one or a plurality of logical links. A control device that controls a communication device that is redundant by a substitutable lower device and is configured to enable continuous communication by being provided with a plurality of lower devices that can be connected to a lower line. , A step of creating at least one higher-level device to which the lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, and a step of updating the firmware of at least one higher-level device to which the lower-level device is not connected. And, a step of updating the firmware of the lower device, and a step of updating the firmware of the lower device include a step of redundant switching and selecting a compatible upper device.

According to the above, in a communication device having a redundant configuration on both the upper side and the lower side, the communication device can be controlled so that the firmware on the upper side and the lower side is updated while continuing the communication service.

(4) The communication device according to one aspect of the present invention includes a plurality of redundant higher-level devices so as to be connected to a higher-level network via a plurality of physical links bundled in one or a plurality of logical links. It is provided with a plurality of lower-level devices that are redundant by substitutable lower-level devices and can be connected to lower-level lines, and a control unit. The control unit aggregates the higher-level devices to which the lower-level devices are connected to create at least one higher-level device to which the lower-level device is not connected, and the firmware of at least one higher-level device to which the lower-level device is not connected. The step of updating, the step of updating the firmware of the lower device, and the step of updating the firmware of the lower device are configured to execute, and the step of updating the firmware of the lower device includes a step of redundant switching and selecting a compatible upper device.

According to the above, it is possible to provide a communication device having a redundant configuration on both the upper side and the lower side and capable of updating the firmware on the upper side and the lower side while continuing the communication service.

[Details of Embodiments of the present invention]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a block diagram showing a schematic configuration of a communication device according to an embodiment of the present invention. With reference to FIG. 1, the communication device 100 is a communication device that connects an upper network (not shown) and a lower line 102 (terminal side).

The upper side of the communication device 100 is composed of a plurality of redundant higher-level devices. As shown in FIG. 1, the communication device 100 includes higher-level devices 1-1 and 1-2 connected to a higher-level network by a higher-level line 101. The upper line 101 includes communication lines 101-1 and 101-2. The communication lines 101-1 and 101-2 realize a physical link to the upper network. In this embodiment, the plurality of physical links to the upper network are bundled and bundled into one or a plurality of logical links. That is, the communication device 100 is connected to the upper network by link aggregation. Each of the communication lines 101-1 and 101-2 may be a single line or may be composed of a plurality of lines. However, in order to facilitate the illustration, each of the communication lines 101-1 and 101-2 is represented by one line in FIG. 1 and the drawings described below.

On the other hand, the lower side of the communication device 100 is composed of a plurality of redundant lower devices. The plurality of lower devices include a plurality of normal systems and at least one spare system. Each normal system is connected to a communication line constituting a lower line and accommodates one or more terminals (not shown).

In the configuration shown in FIG. 1, the communication device 100 includes a plurality of normal systems (lower devices 2-1 and 2-2) and one backup system (lower devices 2-3). The lower devices 2-1 and 2-2 are connected to the communication lines 102-1 and 102-2 constituting the lower line 102, respectively.

The lower devices 2-3 can be connected to the communication line 102-1 or the communication line 102-2 by the switch 5. Further, the lower devices 2-3 can be separated from both the communication line 102-1 and the communication line 102-2 by the switch 5. Therefore, the lower device 2-3 can substitute the traffic of the lower device 2-1 or the lower device 2-2. In one embodiment, each of the lower devices 2-1, 2, 2-3 is realized by a replaceable board. If a board fails, the failed board is replaced with a new board.

The upper devices 1-1, 1-2 and the lower devices 2-1, 2, 2-3 are connected to the switch 3, and the switch 3 is configured so that the connection destination (transmission destination) can be selected. According to FIG. 1, the lower device 2-1 and the lower device 2-2 are connected to both the upper device 1-1 and the upper device 1-2. Therefore, each of the upper device 1-1 and the upper device 1-2 aggregates the traffic of the lower device 2-1 and the lower device 2-2.

The external device 8 sends an instruction to the control unit 4 in response to an input from an operator (not shown). The control unit 4 controls the communication device 100 in response to an instruction from the external device 8. Further, the switch 5 switches the connection destination according to an instruction from the control unit 4. In this embodiment, the control unit 4 is provided inside the communication device 100. Further, the control unit 4 may be provided outside the communication device 100. In such a case, the control unit 4 realizes the control device of the communication device 100.

Hereinafter, an example of a method of updating the firmware of the communication device 100 according to the embodiment of the present invention will be described with reference to FIGS. 2 to 10. The means for providing the firmware to the upper device and the lower device is not particularly limited. For example, new firmware may be provided from the external device 8 to the upper device and the lower device via the control unit 4.

As shown in FIG. 2, first, the switch 3 aggregates the traffic of the lower device 2-1 and the lower device 2-2 into the upper device 1-2. Next, the firmware of the host device 1-1 is updated. As a result, the higher-level device 1-1 whose firmware has been updated and the higher-level device 1-2 whose firmware has not been updated are prepared.

As shown in FIG. 3, the switch 3 disconnects the lower device 2-1 whose firmware has not been updated from the upper device 1-2, and connects the lower device 2-3 to the upper device 1-2. Further, the switch 5 connects the lower devices 2-3 to the communication line 102-1. The traffic that has passed through the upper device 1-1 and the lower device 2-1 is switched to the traffic that has passed through the upper device 1-2 and the lower device 2-3. In this state, the firmware of the lower device 2-1 is updated.

Subsequently, as shown in FIG. 4, the lower devices 2-3 are separated from the communication lines 102-1 and 102-2 by the switch 5. Further, the switch 3 connects the lower device 2-1 to the upper device 1-1. Since the firmware of both the upper device 1-1 and the lower device 2-1 has been updated, the traffic can pass through the upper device 1-1 and the lower device 2-1.

Subsequently, as shown in FIG. 5, the switch 3 disconnects the lower device 2-2 whose firmware has not been updated from the upper device 1-2, and connects the lower device 2-3 to the upper device 1-2. Further, the switch 5 connects the lower devices 2-3 to the communication line 102-2. Therefore, the traffic that has passed through the upper device 1-2 and the lower device 2-2 is switched to the traffic that has passed through the upper device 1-2 and the lower device 2-3. Subsequently, as shown in FIG. 6, the firmware of the lower device 2-2 is updated.

As shown in FIG. 7, the lower devices 2-3 are separated from the communication lines 102-1 and 102-2 by the switch 5. Further, the switch 3 switches the lower device 2-2 so as to be connected to the higher device 1-1. Since the combination of the upper device 1-1 and the lower device 2-2 is a combination of the upper device and the lower device whose firmware has been updated, traffic is permitted. Therefore, the traffic of the lower device 2-1 and the lower device 2-2 is concentrated on the side of the upper device 1-1.

Subsequently, as shown in FIG. 8, the firmware of the host device 1-2 is updated. Further, as shown in FIG. 9, the lower device 2-1 and the lower device 2-2 are connected to both the upper device 1-1 and the upper device 1-2 by the switch 3. After that, as shown in FIG. 10, the firmware of the lower device 2-3 is updated.

As described above, in the embodiment of the present invention, first, by aggregating the upper devices to which the lower devices are connected, at least one higher device to which the lower devices are not connected is created. Next, the firmware of at least one higher device to which the lower device is not connected is updated. In the examples of FIGS. 2 to 4, first, the higher-level devices to which the lower-level devices 2-1 and 2-2 are connected are consolidated into the higher-level device 2-2. As a result, the higher-level device 1-1 becomes a higher-level device to which the lower-level device is not connected. Then, the firmware of the host device 1-1 is updated. Next, the lower device 2-1 selects the upper device 1-1, which is a higher device compatible with the updated version of its own firmware, and updates its own firmware. In this selection, redundant switching and compatible host devices are selected.

By repeating the above procedure, it is possible to update the firmware of all the higher-level devices and all the lower-level devices while continuing the communication service. In the above procedure, regarding the firmware update of the lower device, the firmware of the normal system is updated first, and the firmware of the backup system is updated later. However, embodiments of the present invention are not limited in this way. Regarding the firmware update of the lower device, the backup system firmware may be updated first, and the normal system firmware may be updated later. The procedure for updating such firmware will be described below.

First, as shown in FIG. 2, the switch 3 aggregates all the traffic of the lower device 2-1 and the lower device 2-2 to the side of the upper device 1-2, and the firmware of the upper device 1-1 is released. Will be updated. Next, as shown in FIG. 11, the firmware of the lower device 2-3 (spare system) is updated.

Next, as shown in FIG. 12, the switch 3 disconnects the lower device 2-1 whose firmware has not been updated from the upper device 1-2, and connects the lower device 2-3 to the upper device 1-1. Further, the switch 5 connects the lower devices 2-3 to the communication line 102-1. The traffic that has passed through the upper device 1-2 and the lower device 2-1 is switched to the traffic that has passed through the upper device 1-1 and the lower device 2-3. In this state, as shown in FIG. 13, the firmware of the lower device 2-1 is updated.

Subsequently, as shown in FIG. 14, the switch 3 switches the combination of the upper device 1-2 and the lower device 2-2 to the combination of the upper device 1-1 and the lower device 2-3. Further, the switch 5 connects the lower devices 2-3 to the communication line 102-2. Similar to the example shown in FIGS. 2 to 4, the combination of the upper device 1-1 and the lower device 2-1 that do not generate traffic is determined, and the traffic of the determined combination is transferred to the upper device and the lower device. The firmware of the higher-level device or lower-level device of the determined combination is updated while being replaced by another combination of devices (upper device 1-1 and lower device 2-3). Then, the traffic of the other combination is returned to the traffic passing through the original combination (upper device 1-1 and lower device 2-1).

As shown in FIG. 15, the lower device 2-2 is separated from both the upper device 1-1 and the upper device 1-2, and the firmware is updated. Next, as shown in FIG. 16, the lower device 2-2 is connected to the upper device 1-1 by the switch 3, and the lower device 2-3 is separated from the upper device 1-1. Further, the switch 5 disconnects the lower devices 2-3 from the communication lines 102-1 and 102-2. As a result, the traffic of the lower device 2-1 and the lower device 2-2 is concentrated on the side of the upper device 1-1. In this state, the firmware of the host device 1-2 is updated. As shown in FIG. 17, the traffic of the lower device 2-1 and the lower device 2-2 is also connected to the upper device 1-2.

In FIG. 2, the traffic of the lower device 2-1 and the lower device 2-2 may be aggregated on the side of the upper device 1-1 to update the firmware of the upper device 1-2. In this case, the subsequent update procedure is equivalent to the replacement of the host device 1-1 and the host device 1-2 in the above description. Further, in FIG. 3, the traffic of the lower device 2-2 (normal system) may be switched to the lower device 2-3 (spare system), and the firmware of the lower device 2-2 may be updated. The update procedure in this case is equivalent to the replacement of the lower device 2-1 and the lower device 2-2 in the description of FIGS. 4 to 7. Similarly, the firmware of the lower device 2-2 may be updated first from the state shown in FIG. The update procedure in this case is equivalent to the replacement of the lower device 2-1 and the lower device 2-2 in the description of the drawings after FIG.

The communication device according to the embodiment of the present invention is a communication device that mediates between the upper network and the lower network, and can be applied to a communication device having a redundant configuration on each of the upper network and the lower network. .. In particular, the communication device according to the embodiment of the present invention is suitable for a communication device that accommodates a plurality or a large number of subscriber lines on the lower side, and can be applied to, for example, a PON station side device.

FIG. 18 is a block diagram for explaining an example of application of the PON of the communication device according to the embodiment of the present invention to the station side device. As shown in FIG. 18, the communication device 100, which is a station-side device, includes a higher-level device 1-1, 1-2 and a board 22-1,22-2, ..., 22-M, which corresponds to a lower-level device. A 23, a switch 3, and a control unit 4 are provided. M (M is an integer of 2 or more) boards 22-1,22-2, ..., 22-M are normal systems, and the board 23 is a spare system. A maximum of N communication lines (N is an integer of 2 or more) can be connected to each of the boards 22-1, 22, 2, ..., 22-M. Illustratively, communication lines 112-1, 112-2, ..., 112-N are connected to the board 22-1. Each communication line is specifically an optical fiber, and an optical splitter 104 is connected to each communication line. A plurality of optical fiber branch lines are branched from the optical splitter 104, and the home-side device 103 is connected to the optical fiber branch lines.

The board 23 is connected to switches 5-1, 5-2, ..., 5-N. Each of the switches 5-1, 5-2, ..., 5-N is a 1: M switch, and the corresponding communication lines of the boards 22-1,22-2, ..., 22-M (total). The connection destination of the board 23 (spare system) is switched between the M communication lines). Even in such a configuration, the firmware mounted on the upper device 1-1, 1-2 and the lower device (boards 22-1,22-2, ..., 22-M, 23) is installed according to the above procedure. Can be updated.

In the above embodiment, the lower device selects its own connectable upper device after updating its own firmware. However, there may be cases where the compatibility between the host device and the host device does not change before and after updating the firmware of the host device. Therefore, if both the higher-level devices 1-1 and 1-2 are compatible, the lower-level device selects a higher-level device to which the lower-level device can be connected according to the instruction of the control unit 4, and the lower-level device 1-1, 1 If only one of -2 is compatible, the lower device may select the higher device having the compatibility.

Further, in a configuration in which the control unit 4 is provided inside the communication device 100 or a configuration in which the control unit 4 is provided outside the communication device 100, the control unit 4 controls the communication device to control the firmware according to the embodiment of the present invention. You may control the update procedure.

Further, in the above-described embodiment, the number of higher-level devices is 2, but the embodiment of the present invention can also be applied to a communication device including three or more higher-level devices.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims rather than the above-described embodiment, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

1-1, 1-2 Upper device 2-1, 2-2 Lower device (normal system)
2-3 Lower device (spare system)
3,5,5-1,5-2,5-N switch 4 Control unit 8 External device 22-1,22-2,22-M board (normal system)
23 board (spare system)
100 Communication device 101-1, 101-2, 102-1, 102-2, 112-1, 112-2, 112-N Communication line 101 Upper line 102 Lower line 103 Home side device 104 Optical splitter

Claims (4)

Multiple higher-level devices that are redundant so that they are connected to the upper network via multiple physical links that are bundled into one or more logical links, and redundant lower-level devices that are redundant and become lower-level lines. It is a method of updating the firmware of a communication device configured to enable continuous communication by providing a plurality of connectable lower devices.
A step of creating at least one higher-level device to which the lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, and
A step of updating the firmware of the at least one higher-level device to which the lower-level device is not connected,
A step of updating the firmware of the lower device is provided.
In the step of updating the firmware of the lower device, a higher device capable of redundant switching with another higher device among the plurality of higher devices and having compatibility with the lower device after updating the firmware. selecting, firmware update method for a communication apparatus. The plurality of lower devices are more than the plurality of higher devices.
The step of updating the firmware of the host device is
A step of updating the firmware of a part of the higher-level devices among the plurality of higher-level devices to prepare a higher-level device whose firmware has been updated and a higher-level device whose firmware has not been updated.
The step of disconnecting the lower device whose firmware has not been updated from the higher device whose firmware has not been updated, and
The step of updating the firmware of the unupdated lower device, and
The method for updating firmware of a communication device according to claim 1, further comprising a step of connecting a lower device whose firmware has been updated to the updated higher device. Multiple higher-level devices that are redundant so that they are connected to the upper network via multiple physical links that are bundled into one or more logical links, and redundant lower-level devices that are redundant and become lower-level lines. It is a control device that controls a communication device configured to enable continuous communication by providing a plurality of connectable lower-level devices.
The control device is
A step of creating at least one higher-level device to which the lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, and
A step of updating the firmware of the at least one higher-level device to which the lower-level device is not connected,
The step of updating the firmware of the lower device and the step of updating the firmware of the lower device are configured to execute, and the step of updating the firmware of the lower device can be redundantly switched with another higher device among the plurality of higher devices. A control device for a communication device, which includes a step of selecting a higher device compatible with the lower device after updating the firmware. Multiple higher-level devices that are redundant so that they are connected to the higher-level network via multiple physical links that are bundled into one or more logical links.
Multiple sub-devices that are redundant with substitutable sub-devices and can be connected to the sub-line,
The control unit is provided with a control unit.
A step of creating at least one higher-level device to which the lower-level device is not connected by aggregating the higher-level devices to which the lower-level device is connected, and
A step of updating the firmware of the at least one higher-level device to which the lower-level device is not connected,
The step of updating the firmware of the lower device and the step of updating the firmware of the lower device are configured to execute, and the step of updating the firmware of the lower device can be redundantly switched with another higher device among the plurality of higher devices. A communication device including a step of selecting a higher device compatible with the lower device after updating the firmware.

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