JP2002232441A - Communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide low-cost rack-type communication equipment with high performance and superior expandability. SOLUTION: Wiring constituted in a plurality of ring types on a mother board through a plurality of switches and wiring connected to a plurality of communication circuit boards from wiring are arranged. The switches are changed over in accordance with the attachment/detachment of the board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of a communication device, and in particular, proposes a rack-type communication device excellent in expandability.

[0002]

2. Description of the Related Art At present, large-scale offices use a time-division multiplexing device, a switching device, or the like to provide a large-scale LAN (Local Area Network).
etwork).

FIG. 6 is a diagram showing a configuration of a LAN using a time division multiplexing apparatus.
611 to 618 and 621 to 628 are terminal devices, 610 is a HUB device, 631 and 641 are time division multiplexing units, 632,
642 is an insertion section, 633 and 643 are distribution sections, and 634 and 6
44 is a separation unit, 635 and 645 are optical transmission units, 636 and 6
46 is an optical receiving unit, and 651 to 658 and 661 to 668 are terminal I / F units. The time division multiplexing devices 603 and 60
4 has the same internal structure as 601 and 602. Each time division multiplexing device is connected by an optical fiber. They are connected by a pair cable or the like.

Referring to FIG. 6, the flow of signals between time-division multiplexing devices will be described. Terminal devices 611-618, 621-6
28 has a network interface with a communication speed of 10 Mbps, for example. Signals from the terminal devices 611 to 618 are input to the terminal I / F units 651 to 658 directly or via the HUB device 610, and the time-division multiplexing unit 631
And time-division multiplexes the eight signals to output at a signal speed of 80 Mbps. This multiplexed signal is added by the insertion section 632 to the separation section 6.
The packet signal sequence coming from 34 is sequentially inserted into the empty packet. This packet signal sequence is, for example, 622 Mbp.
This is a high-speed signal of about s, which is converted into an optical signal by the optical transmission unit 635 and transmitted to the optical fiber transmission line.

[0005] The packet signal sequence transmitted through the optical fiber transmission line is transmitted to the optical receiving section 646 of the time division multiplexer 602.
And is converted into an electric signal. The separation unit 644 detects the destination address of each received packet, separates the packet addressed to the time division multiplexer 602, and passes the other packets through the insertion unit 643 and the optical transmission unit 645 to the time division multiplexer 603.
Sent to The packet separated by the separation unit 644 is distributed by the distribution unit 643 according to the destination, and the terminal I / F unit 661
Through 668 to the destination terminal device.

As described above, a LAN in which each time-division multiplexing device is connected on a ring via an optical fiber is mainly used as a backbone of a large-scale office. On the other hand, a high-speed LAN using a switching device has been widely used in recent years, and an example thereof will be described. FIG. 7 is a diagram showing a configuration of a LAN using a switching device.
717, 723-727, 732-737, 741-7
46 is a terminal device, 751 to 754 are exchange switch units, 7
61-768, 771-778, 781-788, 79
1 to 798 are terminal I / F units. A terminal I / F unit for converting a signal from the exchange switch unit into an optical signal;
It comprises an optical receiver for converting an optical signal from an optical fiber transmission line into an electric signal. The switching devices are connected by optical fiber transmission lines shown by solid lines, and backup optical fibers shown by dotted lines are connected as necessary to take measures against failure.

Referring to FIG. 7, the flow of signals between the switching devices will be described. Each terminal device and the switching device have a communication speed of 1, for example.
It has a 55 Mbps optical interface. The optical packet signal from the terminal device 711 is converted into an electric signal by the terminal I / F section 761, and the destination address is detected by the exchange switch section. When the destination is in the same switching device, the packet signal is sent to the destination terminal I / F unit, converted into an optical signal, and transmitted to the destination terminal device. On the other hand, when it is addressed to another switching device, the terminal I / F connected to the adjacent switching device 702
The packet signal is sent to the unit 768, converted into an optical signal, and transmitted to the adjacent switching device 702. The packet signal input to the terminal I / F unit 772 of the switching device 702 is converted into an electric signal, and the destination address is detected by the switching switch unit 741. If the destination is in the same switching device, the packet signal is sent to the destination optical transmitting / receiving unit. The light is converted into a light transmission signal and transmitted to the destination terminal device. On the other hand, when it is addressed to another switching device, the terminal I / F unit 77 connected to the adjacent switching device 703
The packet signal is transmitted to the switching device 703 and converted to an optical signal and transmitted to the adjacent switching device 703. Similarly, communication is performed by arbitrarily switching the switching switch in each switching device according to the destination of the packet.

When the optical fiber between the switching device 702 and the switching device 703 is broken, the optical fiber between the switching device 702 and the switching device 704 provided for backup is set to be used. Communication is resumed. As described above, a high-speed LAN in which switching devices are connected via an optical fiber has become widespread as a backbone of a large-scale office.

[0009]

Considering the cost of the time-division multiplexing apparatus as shown in FIG. 6, the most expensive parts are the optical transmitting units 635 and 645 and the optical receiving units 636 and 6.
46. Since this part has a high transmission speed of 622 Mbps and uses optical parts such as a laser diode and a photodiode, the part cost is higher than other parts operated at a low speed by an electric signal. The place where such expensive equipment is used is a place where there are several hundred meters to several tens of kilometers between time-division multiplexing devices,
Because there was no other way but to use such a high-speed optical signal,
High costs were also accepted.

[0010] However, when the transmission distance is used in a narrow range such as several meters to several hundreds of meters, transmission by such a high-speed optical signal is not acceptable in terms of cost. In other words, when a large number of users use a narrow area within several hundred meters, the conventional time-division multiplexing apparatus has a problem that the cost is too high. Also,
In the above-mentioned ring type network, there is a problem that the entire network is stopped due to the disconnection of the optical fiber. Measures were taken, such as backing up and restoring.

However, the cost required for the duplication not only significantly increases the hardware cost, but also
Network management software was also complicated, and there were problems that took time to develop.

In addition, when the number of users is increased and a time division multiplexing device is added, there is a problem in that it takes time and labor to change the laying of the optical fiber and the cost for adding the device increases.

On the other hand, in a network using the switching device as shown in FIG. 7, the transmission speed of the optical transceiver is 155 Mbps.
If the transmission distance is within about 2 km, L
Since an inexpensive optical component such as an ED can be used, a network can be provided relatively inexpensively regardless of the distance.

However, in a network using switching devices, both the transmission speed of the terminal device and the transmission speed between the switching devices are 155 Mbps. Therefore, when a signal is transmitted from a large number of users between the switching devices, the packet is transmitted. Has been discarded or transmission delay has increased, resulting in deterioration of transmission quality.

To prevent this, there is a method of configuring a network as shown in FIG. In FIG. 8, 801 to 80
4 is a terminal interface with a transmission speed of 155 Mbps and 6
An exchange device having a 22 Mbps backbone interface, 851 to 854, an exchange switch unit, 861
868 and 871 to 878 are terminal I / F units with a transmission speed of 155 Mbps, and 881 to 884 are transmission speeds of 622 Mbps
s is the backbone I / F section. 805 is the transmission speed 6
A backbone switching device of 22 Mbps, 855 is a switching unit, and 885 to 888 are transmission speeds of 622 Mbps.
ps backbone I / F. Terminals 811-814, 821-823, 83 between switching devices and switching devices
The optical fibers 2 to 834 and 841 to 814 are connected.

By connecting the switching devices 801 to 804 with the backbone switching device 805 in this way, the transmission capacity between the switching devices 801 to 804 becomes 622 Mbps, so that the transmission quality can be prevented from deteriorating. .

However, such a configuration requires a high-speed backbone switching device and an optical interface with a transmission speed of 622 Mbps like a time-division transmission device. When used by users, there was a problem that the cost was too high.

In order to prevent a network failure due to disconnection of an optical fiber between the switching devices, at least two switching devices are connected to each other as shown in FIGS. The operation to switch to the other route is performed when one of the locations is disconnected.

Such a countermeasure for the failure hardly increases the hardware cost, but complicates the routing software, increases the development period as in the case of the time division multiplexing apparatus, and eventually increases the cost. Was.

In addition, when an additional switching device is added, it takes time and effort to change the connection relationship between the switching devices, and there is a problem that the additional cost is increased.

[0021]

A communication device according to the present invention comprises at least a plurality of communication circuit boards having terminal interfaces and a motherboard, and the motherboard is provided with a plurality of ring-type devices via a plurality of electric or mechanical elements. A plurality of wirings for extracting signals from the plurality of ring-shaped wirings to the plurality of communication circuit boards, and a plurality of ring-shaped wirings formed from the plurality of communication circuit boards. A plurality of wirings for inserting signals into the wirings are provided.

Here, the plurality of electric elements or mechanical elements are switch elements that are turned on / off by a control signal.

When the communication circuit board is mounted, the electric element or the mechanical element is turned off, and when the communication circuit board is removed, the electric element or the mechanical element is turned on.

Further, the electric element includes an element having a function of connecting the input packet signal to the plurality of ring-shaped wirings or the communication circuit board, and an element having a function of connecting the plurality of ring-shaped wirings. It may be configured by an element having a function of selecting and outputting a packet signal and a packet signal from the communication circuit board.

When a plurality of communication devices of the present invention are used, two transmission boards for connecting the plurality of communication devices are mounted, and the electric element or the mechanical element corresponding to one of the transmission boards is turned off. State, the electrical element or the mechanical element corresponding to the other transmission board is turned on and operated, and when a failure is detected on one of the transmission boards, the electrical element or the mechanical element corresponding to the one transmission board is turned on. And turning off the electric element or the mechanical element corresponding to the other transmission board and transmitting the fault detection information, and when detecting the fault detection information, similarly, the electric element or the machine corresponding to the one transmission board. By turning on the element and turning off the electric element or mechanical element corresponding to the other transmission board and restarting the operation, the optical fiber It is the operation that corresponds to the disconnection of the bus.

Also, two transmission boards for connecting a plurality of communication devices are mounted, and the electric element corresponding to one transmission board is connected to the one transmission board so that an input packet signal is connected to the one transmission board. A packet signal from one transmission board is set to connect to the plurality of ring-shaped wirings, and the electric element corresponding to the other transmission board is configured such that an input packet signal is configured to the plurality of ring-types. And operate so that a packet signal from the transmission board is not selected, and when a failure is detected on one of the transmission boards, the electric element corresponding to one of the transmission boards is transmitted to an input packet signal. Are connected to the plurality of ring-shaped wirings, set so as not to select a packet signal from one transmission board, and set the other transmission board. The input element is connected to the other transmission board, and the packet signal from the other transmission board is connected to the plurality of ring-shaped wirings. Sending the fault detection information, if the fault detection information is detected, similarly, the electrical element corresponding to one of the transmission boards, so that an input packet signal is connected to the plurality of ring-shaped wiring, The packet signal from the one transmission board is set so as not to be selected, and the electric element corresponding to the other transmission board is connected to the other transmission board so that the input packet signal is connected to the other transmission board. The packet signal may be connected to the plurality of ring-shaped wirings to resume operation.

The above problem is solved by configuring the housing as described above.

[0028]

(Embodiment 1) FIG. 1 is a view showing a first embodiment of the present invention. In FIG. 1, 100 is a communication device, 101 is a motherboard, 102 to 105 are exchange units, 111 to 118 are terminals, 121 and 122 are exchange switch units, 131 to 138 are terminal I / F units, and 141 to 1.
44 is a switch unit. The replacement unit 104,
The internal configuration of 105 is the same as 102 and 103.

The communication apparatus 100 is a rack-type apparatus having a plurality of slots, and can be operated according to the number of users by inserting and removing the exchange units 102 to 105. That is, in the figure, four replacement units are mounted, and 16
Although the user is shown to use this communication device, it is also possible to mount only the exchange unit 103 and operate with only four users, for example.

The motherboard 101 includes switches 141 to 1
This is a board on which four ring transmission paths A to D are formed via 44, and is fixed to the communication device 100. The switches 141 to 144 are electrical or mechanical switches, and are replaced by the exchange units 102 to 1 by an external control signal.
It is controlled so that it is turned off when it is connected to the motherboard 101 and turned on when it is not connected. When the exchange unit is connected and the switch is in the off state, the exchange switch unit 121 in the exchange unit,
A part 122 forms a part of the ring transmission line of A to D. The exchange switch sections 121 and 122 are 8-input and 8-output 8-port switches. Four ports are connected to respective ring transmission lines on the motherboard, and the other four ports are terminal I / F sections 131 to 134 and 135 to 138. It is connected to the. The exchange capacity of the exchange switch may be appropriately selected according to the speed of the terminal I / F.
In the case of bps, a switch of 10 Mbps × 8 is used.
In the case of 5 Mbps, a switch having an exchange capacity of 155 Mbps × 8 may be used. Terminal I / F units 131 to 13
Reference numeral 8 denotes a device for transmitting / receiving a signal to / from the terminals 111 to 118 via an optical fiber, and a transceiver including an electro-optical converter and an encoder is used. Also, signals can be transmitted and received via a twisted pair cable, in which case a transceiver with an electrical interface is used. In addition, when using an optical fiber, transmission over several kilometers is possible, and when using a twisted pair cable, 1 kilometer can be used.
Transmission of about 00 meters is possible.

Next, the signal flow will be described. now,
If the exchange units 102 and 103 are the motherboard 101
And 104 and 105 are not connected,
An example of communication from the terminal 115 to the terminal 111 will be described. Transmission speed 155Mbps output from terminal 115
Is input to the terminal I / F unit 135 of the switching unit 103 through the optical fiber transmission line. The terminal I / F unit 135 converts the optical signal into an electric signal and outputs the electric signal to the input terminal D5 of the exchange switch unit 122. The exchange switch unit is a packet switch such as an ATM switch, for example, performs packet buffering and address detection at an input unit, adjusts a packet signal from another input terminal and timing, and outputs the result to a target output terminal. In this switch unit, output terminals Q1 to Q4 are connected to ring transmission lines A to D on the motherboard, and output terminals Q5 to Q8 are connected to terminal I / F units 135 to 13.
8, when the destination of the packet is a terminal connected to another switching unit, the packet may be output to any of the output terminals Q1 to Q4. I do. Although the output packet is input to the switching unit 104 and the switch 143, the switching units 104 and 105 are not connected to the motherboard 101 and the switches 143 and 144 are in the ON state, so that the packets pass through the A transmission paths of the switches 143 and 144. To the exchange unit 102 and the switch 141. Here, the exchange unit 102 is connected to the motherboard 101 and the switch 141 is off, so that the packet is input only to the input terminal D1 of the exchange switch unit 121. The exchange switch unit 121 performs packet buffering and address detection, adjusts a packet signal from another input terminal and timing, and outputs the result to a target output terminal Q5. The output packet is converted into an optical signal by the terminal I / F section 131 and sent to the terminal 111 through the optical fiber transmission line. Communication is performed in this manner.

In this situation, if the number of terminals connected to the network increases, the replacement unit
Communication can be performed simply by adding the information 04 and 105 as appropriate.
When the switching units 104 and 105 are added, the input / output terminals of the switching unit are connected to the ring transmission lines A to D on the motherboard 101, and the switches 143 and 144 are turned off. 103
Are output from the switching units 104 and 105
It is sent to the exchange unit 102 through the above exchange switch.

Thus, the number of users can be easily expanded simply by connecting the exchange unit to the motherboard. Further, even if the switching units are expanded, the transmission speed operates at 155 Mbps in any part, and a communication capacity of 155 Mbps × 4 = 622 Mbps is secured between the switching units.

When the exchange unit has failed, the failed exchange unit sends a control signal to the switch unit to turn on the switch unit and set the output terminal of the exchange switch unit to a high impedance state. Packets can be prevented from passing through the unit. In this way, it is possible to easily take measures against a failure.

In this embodiment, the number of exchange boards and the number of terminal I / Fs are described as 4 and 4 for the sake of simplicity. However, in practice, the number of exchange boards is 8 and the number of terminal I / Fs is 1.
The number can be set to 6 or more, and the communication device of the present invention can cover 8 × 16 = 128 or more users.

(Embodiment 2) FIG. 2 is a view showing a second embodiment of the present invention. In FIG. 2, reference numeral 202 denotes a communication device;
Is a motherboard, 202, 204, 206, and 208 are separation units, 203, 205, 207, and 209 are insertion units, and the other parts are the same as those in the first embodiment. Separation unit 202,
Reference numerals 204, 206, and 208 detect the destination address of the input packet. If the destination is addressed to the switching unit connected to the demultiplexing unit, the packet is output to the switching unit. Otherwise, the packet is output to the transmission lines A to D. Things. Alternatively, when the exchange unit is connected to the motherboard without detecting the destination address, all the input packets are output to the exchange unit side, and when the exchange unit is not connected, all the packets are transmitted to the transmission paths A to D. May be output.
Insertion units 203, 205, 207, and 209 are transmission lines A to D
This is to insert the packet from the exchange unit into the gap of the packet flow from. When the exchange unit is connected to the motherboard, all packets from the exchange unit may be output to the transmission lines A to D.

Next, the signal flow will be described. As in the first embodiment, an example will be described in which, when the exchange units 102 and 103 are connected to the motherboard 101 and the exchange units 104 and 105 are not connected, the terminal 115 communicates with the terminal 111. Transmission speed 155 output from terminal 115
The Mbps packet signal is input to the terminal I / F unit 135 of the switching unit 103 through the optical fiber transmission line. The terminal I / F unit 135 converts the optical signal into an electric signal and outputs the electric signal to the input terminal D5 of the exchange switch unit 122. Since the destination of the packet is a terminal connected to another switching unit, the switching unit 122 outputs the packet to Q1 with less traffic here. The output packet is inserted into the insertion unit 205
Is inserted into the gap of the packet flow sent from the separation unit 204.

The packet stream from the demultiplexing unit 204 has a transmission speed at least higher than the signal speed from the exchange switch 122. If the packet stream has a free space, it is inserted into that portion. Buffered until there is. The packet inserted into the packet stream by the insertion unit 205 is input to the separation unit 206. Since the destination of the packet is a terminal connected to another switching unit, the separating unit 206 outputs the packet to the transmission path A, and inputs the packet to the inserting unit 207. The insertion unit 207 similarly outputs the packet to the transmission line A, and thereafter, similarly, the separation unit 208 and the insertion unit 2
09 and input to the separation unit 202. Since the destination of the packet is destined for the terminal connected to the switching unit 102, the separating unit 202 outputs the packet to the switching unit 102 side,
The packet is input to the input terminal D1 of the exchange switch 121. The exchange switch unit 121 performs packet buffering and address detection, adjusts a packet signal from another input terminal and timing, and outputs the result to a target output terminal Q5. The output packet is converted into an optical signal by the terminal I / F section 131 and sent to the terminal 111 through the optical fiber transmission line. Communication is performed in this manner.

In this situation, if the number of terminals connected to the network increases, the exchange unit 1
Communication can be performed simply by adding the information 04 and 105 as appropriate.
In the transmission between the separation unit and the insertion unit to which the switching unit is connected, a packet not addressed to the switching unit may pass through the transmission paths A to D or may pass through the switching switch unit of the switching unit. .

Also, even if the replacement unit fails,
Since the failure does not spread to other parts, it is possible to easily take measures against the failure.

(Embodiment 3) FIG. 3 is a view showing a third embodiment of the present invention. The communication device 300 of the present embodiment is the
Exchange unit 105 used in the communication device 100 of FIG.
Is changed to an optical unit 301, 302 is an optical transmitting unit, and 303 is an optical receiving unit. FIG. 4 is a diagram in which the communication devices of FIG. 3 are connected by optical fibers, where 401 to 403 are the communication devices of FIG. 3, and arrows are multi-core optical fibers.

The optical unit 301 is a unit for extracting signals on the transmission paths A to D on the motherboard to the outside of the communication device as optical signals.
Is converted from an electric signal to an optical signal and transmitted to the optical fiber transmission line, and the optical receiving unit 303 converts the optical signal from the optical fiber transmission line into an electric signal and connects to the transmission lines A to D. Reference numerals 302 and 303 each include an optical interconnection module or the like in which optical elements are arranged in parallel, and a multi-core fiber such as a ribbon fiber can be suitably used for the optical fiber transmission line. However, the signal may be accommodated in one optical fiber by using any multiplexing means such as time division multiplexing or wavelength multiplexing, or the multiplexed signal may be transmitted using a coaxial cable or wireless means.

This embodiment shows an expansion method in the case where the number of users increases and the number of terminal I / Fs becomes short in one communication device. As shown in FIG. This is achieved by connecting with optical fibers. In FIG. 4, the optical transmission unit 30 of the communication device 401
1 is connected to the optical receiver 302 of the communication device 402, the optical transmitter 302 of the communication device 402 is connected to the optical receiver 303 of the communication device 403, and the optical transmitter 3 of the communication device 403
03 is connected to the optical receiving unit 301 of the communication device 401, so that the communication devices 401 to 403 are connected by a ring type optical fiber.

As described in the first embodiment, the optical unit 30
1 is mounted, the switch 144 is turned off, so that the output signal from the optical receiver 303 is
The data is input to the optical transmission unit 301 via 2 to 104, and transmitted to another communication device through an optical fiber. Since signals are similarly transmitted in each communication device, all the switching units are connected in a ring type, and communication is performed between terminals connected to the ring transmission line.

Although the problem of disconnection of the optical fiber occurs in the structure of FIG. 4 as in the conventional example, the problem is solved by the structure of FIG. FIG. 5 is a diagram showing a network configuration. In the communication devices 501 to 503, two optical units 301 for a working system and a standby system are mounted, and each communication device is connected by two optical fibers. It has a double ring configuration. Here, it is assumed that when communication is being performed via the optical unit at the right end of each communication device, a disconnection has occurred at the position indicated by the cross mark. The optical receiving unit of the communication device 503 detects the interruption of the optical input, turns on the switch unit 144, and turns off the switch unit 143. Then, the signal is transmitted to the network via the standby optical unit. Here, a signal including fault information is inserted into a part of the signal, and the signal is received by the standby optical unit of the communication device 501. The standby optical unit turns on the switch unit 144 and turns off the switch unit 143, and further transmits a signal including fault information from the optical transmission unit to the communication device 502. In the communication device 502, similarly to the communication device 501, the ring is reconstructed by switching to the standby system, and the operation is resumed. In this way, a countermeasure against a failure is taken.

In this embodiment, an example in which an optical unit is mounted on the communication apparatus of the first embodiment has been described. However, even if an optical unit is mounted on the communication apparatus of the second embodiment, operation is similarly performed by a plurality of communication apparatuses. It is needless to say that it is easy to imagine that a failure countermeasure can be taken with the dual configuration.

[0047]

As described above, in the communication apparatus of the present invention, the number of high-speed signal optical transmission units is reduced, so that the cost of the apparatus can be reduced.

Although the present communication device has a ring topology, the number of parts to be considered for disconnection of the wiring is smaller than that of the conventional example, so that it is not necessary to take measures such as complete duplexing and the like. It is now possible to reduce the hardware cost for countermeasures and easily implement network management software.

Further, when the number of users is increased to add an apparatus, basically, it is only necessary to add an exchange unit, and there is no need to change the installation of the optical fiber and the like, and there is an advantage that the addition cost is almost negligible. is there.

Further, even if the number of users is further increased and a plurality of communication devices are used, only the optical transmission unit needs to be duplicated, and the system can be switched more easily than in the conventional example.

Further, since the switching units are connected at a speed several times as high as the terminal speed even when the extension unit is added, there is an effect that the transmission lines are not crowded and the characteristics such as transmission delay do not deteriorate.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating main components of a communication device according to a first embodiment.

FIG. 2 is a diagram illustrating main components of a communication device according to a second embodiment.

FIG. 3 is a diagram illustrating main components of a communication device according to a third embodiment;

FIG. 4 is a diagram illustrating a network configuration according to a third embodiment;

FIG. 5 is a diagram illustrating a failure countermeasure method according to a third embodiment;

FIG. 6 is a diagram showing a network configuration using a conventional time-division multiplexing apparatus.

FIG. 7 is a diagram showing a network configuration using a conventional switching device.

FIG. 8 is a diagram showing another network configuration using a conventional switching device.

[Explanation of symbols]

100, 200, 300, 401-403, 501-5
03 Communication device 101, 201 Motherboard 102-105 Exchange unit

Claims (6)

[Claims] 1. A communication system comprising at least a plurality of communication circuit boards having a terminal interface and a motherboard, wherein the motherboard includes a plurality of ring-shaped wirings via a plurality of electric elements or mechanical elements, and the plurality of rings. A plurality of wirings for extracting signals from the plurality of communication circuit boards to the plurality of communication circuit boards; and a plurality of wirings for inserting signals from the plurality of communication circuit boards to the plurality of ring-shaped wirings. A communication device comprising wiring. 2. The method according to claim 1, wherein the plurality of electric elements or mechanical elements are:
The communication device according to claim 1, wherein the communication device is a switch element that is turned on / off by a control signal. 3. The electric element or the mechanical element is turned off when the communication circuit board is mounted, and the electric element or the mechanical element is turned on when the communication circuit board is removed. The communication device according to claim 2, wherein 4. Two transmission boards for connecting a plurality of communication devices are mounted, said electric element or mechanical element corresponding to one transmission board is turned off, and said electric board corresponding to the other transmission board is turned off. Operate the element or the mechanical element in the ON state, and when a failure is detected in one transmission board, turn on the electric element or the mechanical element corresponding to one transmission board, and the electric element or the corresponding to the other transmission board. When the mechanical element is turned off and fault detection information is sent out, when the fault detection information is detected, the electric element or the mechanical element corresponding to one transmission board is similarly turned on and the other transmission board is 3. The communication device according to claim 2, wherein the operation is restarted by turning off the electric element or the mechanical element. 5. The electric element, comprising: an element having a function of connecting an input packet signal to the plurality of ring-shaped wirings or the communication circuit board; and an element having a function of connecting the plurality of ring-shaped wirings. 2. The communication apparatus according to claim 1, comprising an element having a function of selecting and outputting a packet signal and a packet signal from the communication circuit board. 6. A transmission board for connecting between a plurality of communication devices is mounted, and the electric element corresponding to one of the transmission boards is connected to an input packet signal of the one transmission board. A packet signal from one transmission board is set to connect to the plurality of ring-shaped wirings, and the electric element corresponding to the other transmission board is configured such that an input packet signal is configured to the plurality of ring-types. And operate so that a packet signal from the transmission board is not selected, and when a failure is detected on one of the transmission boards, the electric element corresponding to one of the transmission boards is transmitted to an input packet signal. Are connected to the plurality of ring-shaped wiring, set so as not to select a packet signal from the one transmission board,
The electric element corresponding to the other transmission board is configured such that an input packet signal is connected to the other transmission board, and a packet signal from the other transmission board is connected to the plurality of ring-shaped wirings. When the failure detection information is detected, similarly, when the failure detection information is detected, the electric element corresponding to one of the transmission boards is connected to the plurality of ring-shaped wirings in which an input packet signal is formed. So that the packet signal from the one transmission board is set not to be selected, and the electric element corresponding to the other transmission board is connected to the other transmission board so that the input packet signal is connected to the other transmission board. 6. A packet signal from a board is connected to said plurality of ring-shaped wirings to resume operation.
The communication device as described.