JPH06315041A - Network repeating installation - Google Patents

Abstract

PURPOSE:To prevent data in the middle of transmission held in the inside of a repeating installation mutually connecting plural networks from being dissipated at the time of power interruption in the network repeating installation. CONSTITUTION:In the inside of a repeating installation 43, an uninterruptible power supply system interface part 18 and a telegraphic message table 19 for transmission are provided, and in a routing table 12, a state column is provided. At the time of power interruption of a commercial power source, the installation 43 receives the supply of power by using an uninterruptible power supply system 20, sends a previous stop notise to the other installation during the power supply and sends data held in a transmission/reception buffer 17 to a required route. The other installation receiving the previous stop notice registers it on the state column inside the routing table 12 and afterwards, the transmission of data is controlled without selecting the route through the installation being in power interruption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network relay device, and more particularly, to a network relay device suitable for connecting networks in a network system configured by connecting a plurality of networks. .

[0002]

2. Description of the Related Art As a conventional technique related to a network system configured by connecting a plurality of networks, for example, a network system called Ethernet is known.

In this prior art, a plurality of networks called Ethernet segments are connected to each other via a network relay device to form a network system, and workstations accommodated in each network,
A device such as a computer or a terminal device (hereinafter, these are referred to as workstations as a representative) transmits data between other workstations via the network accommodating its own workstation and the network relay device. Transmission is performed.

According to this conventional technique, when data is transmitted through a plurality of network relay devices, the data from the workstation, which is the source of the data, is transferred to the network containing the device and another network. To a network relay device connected to the network relay device, and then the network relay device transmits data to another network relay device or a network relay device connected to the network containing the receiving workstation. That is.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
A workstation accommodated in a network has a plurality of network relay devices, for example, relay device A,
When sending data to a workstation accommodated in another network via B, C and D, first,
Data is transmitted from the transmitting workstation to the relay device A connected to its own network. When this transmission ends normally, the transmission-side workstation ends transmission normally, the data to be transmitted passes to the relay device A, and the subsequent processing is left to this relay device A.

Next, communication is performed between the relay device A and another relay device B, and when the communication is normally completed, the relay device A is normally completed in transmission, and the data to be transmitted is transferred to the relay device B. After that, the data is passed to the relay devices C and D,
Eventually, the data will be sent to the receiving workstation.

According to the above-mentioned conventional technique, for example, when data is normally transmitted from the relay device B to the relay device C and then the data is transmitted from the relay device C to the relay device D during the data transmission. However, when the power of the relay device C is cut off, the data in the middle of the relay stored in the relay device C disappears, and the data cannot be reproduced.

That is, when such a power failure occurs, the transmitting workstation, the relay device A, and the relay device B have not normally retransmitted the data because the data transmission has been completed normally. Further, since the receiving workstation does not know that the data is being sent, it does not issue a resend request. Therefore, the data sent by the sending workstation to the receiving workstation is
It has been lost by the relay device C.

In order to prevent the loss of data due to a power failure of the relay device as described above, there is a method of connecting an uninterruptible power supply device to each relay device and supplying power from the uninterruptible power supply device when a power failure occurs. With this, it is possible to transmit the data held by the relay device to the next relay device. However, with this method, if the power failure lasts for a long time, the power supply from the uninterruptible power supply will eventually stop, and in that case, as in the case described above, the data inside the power failure relay device will disappear. This will cause the problem of doing.

An object of the present invention is to solve the above-mentioned problems of the prior art and to prevent the data in the middle of the relay held by the relay device from being erased when a power failure occurs. To provide a device.

[0011]

According to the present invention, the object is to provide an uninterruptible power supply in a relay device, an interface section with the uninterruptible power supply, and a route in a routing table used for route selection. And a part for recording the state of the, and when a power failure occurs, while the relay device is being supplied with power from the uninterruptible power supply, other relay devices, networks, and workstations are notified of the stoppage. It is achieved by transmitting all the data to be transmitted which is held internally.

[0012]

When the power failure occurs, the relay device receives the power failure occurrence signal from the uninterruptible power supply device and transmits the stop advance notice message to other relay devices, networks, and workstations connected to the relay device itself. The other relay device receiving this changes the state of the corresponding route in the routing table to the power failure state. As a result, the other relay device thereafter performs communication using another normal path.

This prevents the data from being sent to the relay device in which the power failure has occurred. On the other hand, the relay device in which a power failure has occurred transmits all the data in the middle of relaying inside while the power is being supplied from the uninterruptible power supply device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a network relay device according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a network system to which the present invention is applied, and FIG. 3 is an example of a routing table provided in each relay device. It is a figure explaining. In FIG. 1 and FIG. 2, 11 is a control unit, 12 is a routing table, 13 is a power supply, 14 is a timer, 15 is a transmission / reception unit, 16 is an external network connection port, 17 is a transmission / reception buffer, and 18 is an uninterruptible power supply interface ( UP
S I / F) section, 19 is a transmission message table, 20 to 2
2 is an uninterruptible power supply (UPS), 43 to 47 are relay devices AE, 51 and 52 are workstations (WS), X
1 to X7 are Ethernet segments. One embodiment of the present invention applies the present invention to an Ethernet system. First, a configuration example of a network system to which the present invention is applied will be described with reference to FIG.

The network system shown in FIG. 2 is configured by connecting a plurality of Ethernet segments X1 to X7 to a plurality of relay devices A43 to E47, and connecting these relay devices to each other. The workstation 51 is connected to the Ethernet segment X1,
An uninterruptible power supply 21 is connected to the workstation 51 in order to prevent files from being destroyed at the time of power failure.

In the example shown in FIG. 2, the uninterruptible power supply device is connected only to the relay device C45 for simplification of the drawing, but in the present invention, the uninterruptible power supply device is connected to all the relay devices. To be done.

The workstation 51 is capable of communicating with other workstations in the Ethernet segment X1 and is also connected to other Ethernet segments via the relay device A43 connected to the Ethernet segment X1. Can communicate. For example, the workstation 51 is different from the workstation 52 connected to the Ethernet segment X5 in the relay device A43, the relay device B44, the relay device C45, the relay device D46, and the Ethernet segment X.
Communication can be carried out via

By the way, as shown in FIG. 2, when the relay devices are connected in a loop, the communication route between the workstations 51 and 52 is the relay device A43 and the relay device E47 in addition to the above routes. There is also a route via the relay device D46 and the Ethernet segment X5.

Known methods for determining the route are static routing in which the route is determined in advance and dynamic routing in which the route information is exchanged between the relay devices and the optimum route is automatically selected. The optimum route here is, for example, a route that minimizes the communication delay time, a route that minimizes the number of transiting devices, or the like. Shall be selected.

The route information is registered in the routing table provided in each relay device, and in dynamic routing, the contents of this table are updated to the latest information at regular time intervals. As will be described later, in this table, the IP network address of the Ethernet segment, the distance between the relay devices from the relay device to the connected relay device of the corresponding Ethernet segment, and the relay that transmits the next data when the corresponding route is taken. Device name, port name to which the cable to the relay device is connected, and
The state of the route is written. When there are two or more routes such as the route from the Ethernet segment X1 to the Ethernet segment X5 described above, all the information is written in the above table.

Now, the relay devices A43, B44, C45,
The distances of the relay lines that connect D46 and E47 to each other are l, m, n, p, and q, respectively, and the distance between the two relay devices from the relay device A43 to the relay device D46 is (l + m + n) <(p + q) In the case of sending data from the workstation 51 to the workstation 52, the relay device A43 connected to the Ethernet segment X1 is the route (l + m + n) as the shortest route to the Ethernet segment X5. Is selected and the data is sent to the relay device B44. Then, this data reaches the Ethernet segment X5 via the relay device B44, the relay device C45, and the relay device D46, and is sent to the workstation 52.

By the way, for some reason, the relay device C
When the relay device 45 is stopped, the route information is exchanged between the relay devices at regular time intervals. Therefore, after a while after the relay device C45 is stopped, the relay device A43 routes the route from the routing table to the relay device C45. To delete. In this case, the relay device A43 serves as a route from the workstation 51 to the Ethernet segment X5 for transmitting data to the workstation 52 (p.
+ Q) is selected, and the data is sent from the relay device A43 to the relay device E47. Then, this data reaches the Ethernet segment X5 via the relay device E47 and the relay device D46 and is sent to the workstation 52.

The operation of the embodiment of the present invention described above is the same as that of the prior art. Next, the configuration of the relay device according to the embodiment of the present invention and the operation peculiar to the present invention will be described with reference to FIG. ~ It demonstrates with reference to FIG.

A relay device according to an embodiment of the present invention is shown in FIG.
As an example of the relay device A43, a control unit 11 that controls the entire device, a routing table 12 that is used to dynamically determine a route, a power supply 13,
The timer 14, the transmission / reception unit 15, the external network connection port 16, the transmission / reception buffer 17, the uninterruptible power supply interface unit 18, and the transmission message table 19 are configured, and further, the uninterruptible power supply 20 is connected. .

A relay device according to an embodiment of the present invention is
The difference from the device according to the prior art is that the uninterruptible power supply 2
An uninterruptible power supply interface section 18 for exchanging interface signals with 0, a transmission message table 19 for holding messages for notifying other relay devices, workstations, and networks of the state of the relay device itself, and further, The point is that a status column indicating the status of the route is added to the routing table 12.

FIG. 3 shows an example of the specific contents of the routing table provided in each of the relay devices A43 to E47 when the network system is configured as shown in FIG.

In this table, the IP network address of the Ethernet segment, the inter-relay device distance from the own relay device to the connected relay device of the Ethernet segment, and the relay device which transmits the next data when the corresponding route is taken. The name, the port name to which the cable to the relay device is connected, and the state of the route are written. Then, the state of the route is provided by the present invention, and when the entire network system is normal, all "○" are described, and one of the relay devices included in the route indicates "stop relay device". If a "previous notice" is reported,
“X” is described.

In the illustrated example, the port name is specifically shown only for the table of the relay device A43 specifically shown in FIG. 1, and the relay device C45 indicates the relay device stop notice as the route state. Is issued.

As already described, the operation of dynamic routing, which is the original function of the relay device, is the same as the conventional one, so the operation when a power failure occurs will now be described.

When the commercial power supply that supplies power to the repeater A43 loses power, the uninterruptible power supply 20
When this is detected and a "power failure" signal is sent to the relay device as an interface signal, the power of a battery or the like provided inside is converted into AC100V and the relay device A43.
Give to. The uninterruptible power supply interface unit 18 in the relay device A43 receives this signal and notifies the control unit 11 of the occurrence of the power failure.

The control unit 11 that has been aware of the occurrence of the power failure extracts the telegram of "relay device stop notice" from the transmission telegram table 19 and notifies the other relay devices connected to the self relay device and the self relay device. Send the message to a workstation connected through the Ethernet segment.
These destinations are all the relay devices currently in operation registered in the routing table 12 and all the workstations connected to the segment accommodated by the own device.

Now, in the network system having the configuration shown in FIG. 2, it is assumed that a power failure has occurred in the relay device C45. In this case, the relay device C45 knows from the routing table that the relay devices connected to its own relay device are the relay device B44 and the relay device D46, and sends a "relay device stop notice" message to these relay devices. After that, all the data in the middle of the relay in the transmission / reception data buffer 17 are transmitted to the corresponding relay device and the workstation connected to the own relay device via the Ethernet segment.

On the other hand, the relay device that has received the “relay device stop notice” has the status column of the routing table 12 inside each relay device, which is “◯”, which means a normal state,
Change the status column in the section related to the relay device that sent the "relay device stop notice" to "x", which means the stop notice state. In other words, the relay device B44 changes all the status columns of the items whose relay device column is C45 in the internal routing table to "x".

Further, the relay device B44 needs to inform the relay devices other than the relay device C45 which has transmitted the "relay device stop notice" that the communication in the direction of the relay device C45 cannot be performed. Therefore, in the relay device B44, the IP of the item in which the relay device column of the routing table 21 in the relay device B44 is “C” and the status column is “x”.
Along with the network address, the fact that communication in the direction of relay device C45 cannot be transmitted is transmitted to relay device A43. In this example, Ethernet segments X1, X4, X5, X
IP network address x1, x for 6, X7
4, x5, x6, x7 will be transmitted.

The relay device A43 receives from the relay device B44 that the communication to the above-mentioned IP network address cannot be performed, and the relay device column of the routing table in its own device is "B" and the IP network address column is received. "X" in the status column of the item that is the IP network address
Change to. Further, in the relay device A43, the relay device column of the routing table is “B” and the status column is “x”.
The IP network address of the item marked with is transmitted to the relay device E47. In this example, the IP network addresses x4, x5, x6, x7 will be transmitted.

The relay device E47 is the relay device A43.
When the status column of the item in which the relay device column of the routing table in the own device is “A” and the IP network address column is the received IP network address is received from Change to "X". Further, the relay device E47 transmits the IP network address of the item in which the relay device column of the routing table is "A" and the status column is "x" to the relay device D46. In this example, the IP network addresses x4, x5, x6 will be transmitted.

Further, the relay device D46 is the relay device E47.
When the status column of the item in which the relay device column of the routing table in the own device is “E” and the IP network address column is the received IP network address is Change to "X". Further, the relay device D46 transmits to the relay device C46 the IP network address of the item in which the relay device column of the routing table is "E" and the status column is "x". In this example, the IP network address x4 will be transmitted.

Relay device C that issued the "relay device stop notice"
45 is a status column of an item in which the relay device of the routing table is “D” and the IP network address column is the received IP network address x4 when receiving from the relay device D46 that communication to the IP network address is impossible. However, since there is no item satisfying such a condition, no processing is performed. Therefore, the series of processing ends here.

By the way, as described above, the "relay device stop notice" from the relay device C45 which has lost power is also sent to the relay device D46. Therefore, according to one embodiment of the present invention, the relay device D → E → A → B →
Data is also transmitted via C, which also updates the status column of the routing table in each relay device.

As described above, when the relay device C45 has a power failure, the routing table in each relay device is as shown in FIG.
Updated as shown in. Then, after this, each relay device transmits data using only the route whose status column in the routing table is “◯”. This prevents new data from being sent to the relay device that is in power failure, which is the relay device C45 in this example.

The relay device C45 sends out all the data held in the internal transmission / reception buffer 17, and when it finishes, the control unit 11 causes the uninterruptible power supply interface 1 to operate.
A stop signal is output to the uninterruptible power supply 22 via 8. As a result, the uninterruptible power supply 22 stops supplying power,
Therefore, the relay device C45 also stops.

In this way, according to the embodiment of the present invention, by providing the uninterruptible power supply interface 18 with the stop signal, it is possible to prevent unnecessary power supply after the processing of the relay device C45 is completed.

When the relay device C45 is stopped, the other relay devices, due to the dynamic routing function, perform the route related to the relay device C45 from the routing table in its own device, in this example, by the dynamic routing function, as in the prior art. The route whose column is "x" will be deleted.

On the other hand, the commercial power supply recovers power while the relay device C45, which is supplied with power from the uninterruptible power supply during a power outage, is transmitting the data held in the internal transmission / reception buffer. Can be considered. In this case, the relay device C45 transmits a "relay device power recovery report" to the relay devices B44 and D46.

Each relay device thereafter executes the same process as the process performed in the above-mentioned "relay device stop notice" process as a process of changing the status column to "○". As a result, the contents of the routing table in each relay device
It indicates that the entire network system is normal.

In the above-described one embodiment of the present invention, it is explained that the network system has a configuration as shown in FIG. 2 by Ethernet and a power failure occurs in the relay device C45. The present invention can be applied to a network system having any configuration as long as they are connected to each other by a relay device, and also when a relay device other than the relay device C45 has a power failure, the same as above. Can work.

[0048]

As described above, according to the present invention, even if a power failure occurs in a network relay device connecting a plurality of networks, the data held in the relay device is lost. It can be sent to another relay device without causing it.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a network system to which the present invention is applied.

FIG. 3 is a diagram illustrating an example of a routing table provided in each relay device.

[Explanation of symbols]

11 control unit 12 routing table 13 power supply 14 timer 15 transmission / reception unit 16 external network connection port 17 transmission / reception buffer 18 uninterruptible power supply interface (UPS I /
F) section 19 Transmission message table 20-22 Uninterruptible power supply (UPS) 43-47 Repeaters AE 51, 52 Workstation (WS) X1-X7 Ethernet segment

Claims (4)

[Claims] 1. A network relay device for controlling a relay of data by connecting a plurality of networks to each other, and an interface part for transmitting and receiving a signal to and from an uninterruptible power supply device, and a state of a data transmission route from the device itself. And a table for indicating the state of the own device to a device accommodated in a network connected to the own relay device and a table indicating the other A network relay device for reporting a power failure notice to a device and a device accommodated in a network connected to the device. 2. When a power failure occurs, while power is being supplied from the uninterruptible power supply, another relay device adjacent to the relay device or a device accommodated in the network connected to the self device is provided with 2. The network relay device according to claim 1, wherein the data in the middle of relay held in the device is transmitted. 3. When power is restored during transmission of data during the relay, a power recovery report is sent to another adjacent relay device and a device accommodated in a network connected to the own device. The network relay device according to claim 2. 4. The other adjacent relay device, when receiving the power failure notice, changes the state of the table, and thereafter stops the transmission of data to the relay device. 2. The network relay device according to 2 or 3.