JPH11275132A - Information mediation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information mediation device capable of surely mediating the transmission of information transmitted over plural networks with an independently determined address system, including the case that an abnormal state occurs in a repeater. SOLUTION: This device is provided with a correspondence table storage part 1-1 for recording the correspondence table of the address of the communication terminal 27 of a reception destination and the address of a next stage repeater 3, a transmission control means 1-2 for referring to the correspondence table and performing transmission to the next stage repeater 3, and an address rewrite means 1-3 for rewriting the address of the correspondence table to the address of a second next stage repeater 4 in the case that an abnormal state occurs in the next stage repeater 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information mediating device for mediating the transmission of information transmitted over a plurality of networks whose address systems are independently defined.

[0002]

2. Description of the Related Art Conventionally, a communication terminal to which an address is assigned is connected, and a relay device (router) for relaying information transmission is provided on a route to the communication terminal. 2. Description of the Related Art There is known an information intermediary device (gateway) that is connected to a plurality of predetermined networks and mediates transmission of information transmitted across the plurality of networks.

FIG. 2 is a diagram showing a conventional information mediating device and two networks through which information transmission is mediated by the information mediating device. First network 2 shown in FIG.
The second and second networks 23 are networks in which address systems are defined independently of each other. The protocols of the first and second networks 22 and 23 are TCP / IP (Transmission Co.).
ntrol Protocol / Internet P
protocol is used. A communication terminal 27 to which an IP address based on TCP / IP is assigned is connected to the first network 22. Further, the first network 22 is provided with repeaters 24 and 25 for relaying information transmission in the middle of the route to the communication terminal 27. In these repeaters 24 and 25, the communication terminal 2
The number of routes (hop number) to the communication terminal 27 is set based on the IP address of No. 7, and information on the number of routes (hereinafter referred to as route information) is also transmitted. On the other hand, a communication terminal 28 to which an IP address based on TCP / IP is attached is connected to the second network 23, and a relay device 26 for relaying information transmission is provided on a route to the communication terminal 28. Is provided. Also in the repeater 26, the communication terminal 28 is set based on the IP address of the communication terminal 28 in the same manner as the relays 24 and 25 described above.
Is set, and the route information is also transmitted. Although the first and second networks 22 and 23 are provided with a large number of communication terminals and repeaters, here, the communication terminals 27 and 28 and the repeaters 24, 25 and 26 are provided.
Is exemplarily shown.

A first network 22 and a second network 23 have these first and second networks 22,
23, an information mediating device 21 that mediates the transmission of information transmitted across. This information mediation device 21
Is provided with a routing table for storing the route information from the repeaters 24, 25, 26. The information intermediary device 21 is a RIP (Routing Information).
The routing information from the repeaters 24, 25, and 26 is stored in a routing table by using a routing control information protocol such as a communication protocol. In general, the first
Since the number of communication terminals connected to the second networks 22 and 23 increases and decreases, the repeaters 24, 25 and 2
The route information from 6 also changes. Therefore, the information intermediary device 2
In the first method, so-called dynamic routing is generally performed in which the routing table is rewritten by storing the routing information from the repeaters 24, 25, and 26 in the routing table at predetermined time intervals.

The signal converter 29 is connected to the first network 2
2 and the information mediating device 21, the repeaters 24, 25,
Conversion to the signal format of the communication terminal 27, and the signal format of the second network 23 to the information mediating device 21, the repeater 2
6, for conversion with the signal format of the signal terminal 28. Here, when transmitting information from the communication terminal 28 connected to the second network 23 to the communication terminal 27 connected to the first network 22, the routing table of the information mediating device 21 is referred to, , 25, a repeater (for example, the repeater 24) having the path information indicated by the smaller number of paths out of the number of paths indicated by the path information is selected. → Repeater 24 → Communication terminal 27
Information is transmitted through the route.

[0006]

Here, for example, in the first network 22, the first network 2
In some cases, information is transmitted from the communication terminal (not shown) connected to the communication terminal 2 to the communication terminal 27. As described above, since the first and second networks 22 and 23 are networks in which address systems are determined independently of each other, network addresses may be duplicated. Further, in the information mediating device 21, when the dynamic routing is performed, the number of routes indicated by the route information of the repeater 26 provided in the second network 23 is larger than the number of relays provided in the first network 22. In some cases, the number is smaller than the number of paths indicated by the path information of the devices 24 and 25. Then, the network address of the second network 23 is the same as the address of the first network 22, and the number of routes of the repeater 26 is smaller than the number of routes of the repeaters 24 and 25. There is a problem that information is transmitted to the 23 side. Further, when both communication terminals 27 and 28 have the same IP address, a problem that information is transmitted to communication terminal 28 occurs.

On the other hand, if so-called static routing in which the routing table is fixed in advance is adopted,
Since the routing table is not rewritten, if an abnormality occurs in any of the repeaters provided in the first and second networks 22 and 23, the transmission of information is relayed by another route other than the repeater. The problem arises that you cannot do that.

The present invention has been made in view of the above circumstances, and ensures transmission of information transmitted over a plurality of networks whose address systems are independently determined, even when an error occurs in a repeater. It is an object of the present invention to provide an information mediating device that can mediate.

[0009]

According to the present invention, there is provided an information intermediary device which is connected to a communication terminal to which an address is assigned and relays the transmission of information along a route to the connected communication terminal. An information intermediary device that is connected to a plurality of networks each having an address system defined independently of each other and that mediates the transmission of information transmitted between the plurality of networks, provided with: ) A correspondence table storage unit that records a correspondence table between the address of the communication terminal of the reception destination and the address of the next-stage repeater, which is the next relay destination as viewed from the information intermediary device, of the information transmitted to the address. 2) With reference to the correspondence table, transmission control means for transmitting the received information to the next-stage repeater corresponding to the information. (3) An abnormality occurs in the next-stage repeater recorded in the correspondence table. Case, the address of the next-stage repeater in the correspondence table, characterized by comprising an address rewriting means for rewriting the second next stage repeater address in place of the next-stage repeater.

[0010] The information mediating apparatus of the present invention refers to a correspondence table between the address of the communication terminal of the receiving destination and the address of the next-stage repeater, and transfers the received information to the next-stage repeater corresponding to the information. As in the case of conventional static routing, network addresses of multiple networks whose address systems are defined independently of each other are duplicated, or communication terminals in each of the multiple networks are transmitted. Even if the address is duplicated, it is not possible to send the received information to a network different from the receiving network or to a communication terminal different from the receiving communication terminal Therefore, it is necessary to ensure the transmission of information transmitted across multiple networks whose address systems are defined independently of each other. It can be mediated.

Further, when an abnormality occurs in the next-stage repeater,
Since the address rewriting means rewrites the address of the next-stage repeater in the correspondence table with the address of the second next-stage repeater, the received information is transmitted to the communication terminal of the reception destination by the second next-stage repeater. Sent. Therefore, even when an abnormality occurs in the next-stage repeater, the received information can be transmitted to the communication terminal of the reception destination, and the reliability of the transmission of the information is increased.

Here, when the second next-stage repeater has an abnormality in the next-stage repeater whose address is recorded in the correspondence table before the address rewriting means rewrites the correspondence table, It is effective that the repeater is prepared in advance so as to play the role of the next-stage repeater.
If such a repeater is prepared in advance as the second next-stage repeater, if an abnormality occurs in the next-stage repeater before the correspondence table is rewritten by the address rewriting means, it is replaced by the repeater. The nature is further enhanced.

[0013]

Embodiments of the present invention will be described below. FIG. 1 shows an information mediating device according to an embodiment of the present invention, and information transmission is mediated by the information mediating device.
FIG. 3 is a diagram showing two networks. Note that the same components as those shown in FIG.
Duplicate description is omitted.

In the first network 22 and the second network 23, the information mediating device 1 and information prepared in advance to take the role of the information mediating device 1 when an abnormality occurs in the information mediating device 1. The mediation device 2 is connected. Further, the first network 22 includes a next-stage repeater 3 as a next relay destination viewed from the information relay device 1 and a role of the next-stage repeater 3 when an abnormality occurs in the next-stage repeater 3. Is connected to a second next-stage repeater 4 prepared in advance to carry out the following.

The information mediating device 1 has a correspondence table storage unit 1-1.
, Transmission control means 1-2, and address rewriting means 1-3. The correspondence table storage unit 1-1 stores the address of the communication terminal 27 of the reception destination, the address of the next-stage relay device 3 as the next relay destination as viewed from the information intermediary device 1 of the information transmitted to the address, and Is recorded.

The transmission control means 1-2 has a correspondence table storage section 1-
1 and transmits the received information to the next-stage repeater 3 corresponding to the information. The address rewriting means 1-3 is provided with a predetermined program. When an abnormality occurs in the next-stage repeater 3 indicated by the address recorded in the correspondence table, the program is started, and the program is started by the program. The address of the next-stage repeater 3 in the correspondence table is
The address is rewritten to the address of the second next-stage repeater 4 replacing the next-stage repeater 3. The second next-stage repeater 4 is switched in place of the next-stage repeater 3 when an abnormality occurs in the next-stage repeater 3 before the correspondence table is rewritten by the address rewriting means 1-3.

Here, in order for the information mediating device 1 to transmit information from the communication terminal 28 connected to the second network 23 to the communication terminal 27 connected to the first network 22, the information mediating device 1 Correspondence table storage unit 1-1 provided
Is referred to. Since the correspondence table records the correspondence between the address of the communication terminal 27 of the communication destination and the address of the next-stage repeater 3, the information mediating apparatus 1 communicates with the communication terminal 28 connected to the second network 23. And transmits the information received via the repeater 26 to the next-stage repeater 3 corresponding to the information. As described above, the information intermediation device 1 of the present embodiment refers to the correspondence table between the address of the communication terminal 27 of the receiving destination and the address of the next-stage relay device 3 and transmits the received information to the next-stage relay device 3. The first and the first, whose address systems are determined independently of each other,
This is the case where the network addresses of the second networks 22 and 23 are duplicated, or the addresses of the communication terminal and the communication terminal (not shown) in the first and second networks 22 and 23 are duplicated. Also transmits the received information to the second network 2
3 or the communication terminal 27 other than the communication terminal 27 and having a duplicate address with the communication terminal 27.
It is possible to reliably mediate the transmission of the information transmitted between the nodes 23.

If an abnormality occurs in the next-stage repeater 3,
The switching to the second next-stage repeater 4 prepared in advance is performed (this switching will be described later). Further, a predetermined program provided in the address rewriting means 1-3 is activated, and this program causes the next-stage repeater 3 in the correspondence table to execute.
Is rewritten to the address of the second next-stage repeater 4. Therefore, even if an abnormality occurs in the next-stage repeater 3, the received information can be transmitted to the communication terminal 27 of the receiving destination by the second next-stage repeater 4, and the transmission of the information is mediated. In doing so, the reliability increases.

Next, a description will be given of abnormality detection for detecting whether or not an abnormality has occurred in the next-stage repeater 3, the information mediating device 1, and the like. Here, healthy detection using a tool called ping is performed in order to detect an abnormality in the next-stage repeater 3, the information relay device 1, and the like. Note that the information mediating device 1 and the information mediating device 2 are simply referred to as a master system and a slave system. The abnormality detection of the next-stage repeater 3, the main system, and the like by the healthy confirmation is performed as follows.

(1) The slave sends a ping echo request packet to the master, the next-stage repeater 3, and the repeater 26 at one-minute intervals (five times at one-second intervals). The main system, the next-stage repeater 3, and the repeater 26 return a ping echo reply (response) packet if normal. (2) The main system also transmits a ping echo request packet to the next-stage repeater 3 and the repeater 26 at one-minute intervals (five times at one-second intervals). Next-stage repeater 3 and repeater 26
Returns a ping echo reply (response) packet if normal.

(3) The master notifies the ping result to the slave using the inter-system communication path A. (The slave determines that the master is normal if at least one echo reply (response) packet is returned.) Is considered). (4) The slave determines the ping results of the next-stage repeater 3, the repeater 26, and the master based on Tables 1 and 2 described later, and when the switching target abnormal state continues for three minutes, The following processing is performed. If the state changes during the abnormal state monitoring for 3 minutes, the abnormal state monitoring is started again for 3 minutes from that point (the monitoring timer is reset).

1) When the main system is abnormal The sub system sends a "main system shutdown request" message to the inter-system communication path A. The slave switches to the new master after waiting (waiting) for one minute. 2) When the next-stage repeater 3 is abnormal A request for changing the correspondence table is made to the main system using the Ethernet (remote shell: rsh) on the first network 22 side, and the next-stage repeater 3 is switched to the second To the next-stage repeater 4. Further, a request for changing the correspondence table is made to the slave system.

3) When the repeater 26 is abnormal When the repeater 26 on the second network 23 side becomes abnormal, an error message is displayed on the console (the correspondence table is not rewritten). Next, switching determination based on the ping result will be described. The switching determination based on the ping result is performed as follows.

Table 1 is an abnormal point determination table based on the ping results.

[0025]

[Table 1]

Table 1 shows the first and second networks 22,
23 are provided correspondingly. P shown in Table 1
An abnormal point is determined for each of the first and second networks 22 and 23 from the ing result. Here, Table 1
Will be described as a table corresponding to the first network 22, but the same applies to the second network 23.
The ping result (1) shown in Table 1 indicates the ping result from the next-stage repeater 3 to the main system, and the ping result (2)
Indicates the ping result from the next-stage repeater 3 to the slave system, and the ping result (3) indicates the ping from the master system to the slave system.
The results are shown. The router and LAN shown in Table 1 represent the next-stage repeater 3 and the first network 22. Further, in Table 1, a mark “〇” indicates a normal state, a mark “X” indicates an abnormal state, and? The mark means a state in which the result in the master system could not be confirmed in the slave system (such as an inter-system communication path error). The figures in parentheses are estimates.

According to Table 1, the first and second networks 2
2 and 23 are determined, and based on the combination of the determined abnormal points, switching from the master system to the slave system and the next stage repeater 3 The switching to the second-stage repeater 4 is determined. Table 2 is a switching determination table for determining switching from the master system to the slave system and switching from the next-stage repeater 3 to the second next-stage repeater 4.

[0028]

[Table 2]

The crosses shown in Table 2 indicate that switching is not required.
The mark means switching from the next-stage repeater 3 to the second next-stage repeater 4, and the symbol 〇 means switching from the master to the slave (the slave becomes the new master). Further, the mark ◎ indicates switching from the master system to the slave system and from the next-stage repeater 3 to the second next-stage repeater 4.
Means both switches to As described above, in the present embodiment, the information intermediary device 1 and the information intermediary device 2 and the next-stage repeater 3 and the second next-stage repeater 4 are each configured in a so-called duplex configuration. , When an abnormality occurs in the next-stage repeater 3, the information relay device 2, the second next-stage repeater 4
, High reliability is obtained.

[0030]

As described above, according to the present invention,
It is possible to reliably mediate the transmission of information transmitted across a plurality of networks whose address systems are determined independently of each other, even when an error occurs in the repeater.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an information mediating device according to an embodiment of the present invention and two networks through which information transmission is mediated by the information mediating device.

FIG. 2 is a diagram showing a conventional information mediation device and two networks through which information transmission is mediated by the information mediation device.

[Explanation of symbols]

 1, 2 Information Intermediation Device 1-1 Correspondence Table Storage Unit 1-2 Transmission Control Means 1-3 Address Rewriting Means 3 Next Stage Repeater 4 Second Next Stage Repeater 22 First Network 23 Second Network 26 Relay Device 27,28 communication terminal 29 signal converter

Claims (2)

[Claims] An address system is defined independently of each other, wherein a communication terminal to which an address is assigned is connected, and a relay device for relaying information transmission is provided on a route to the connected communication terminal. An information intermediation device that is connected to a plurality of networks and mediates transmission of information transmitted across the plurality of networks, comprising: an address of a communication terminal of a reception destination; and information transmitted to the address. A correspondence table storage unit that records a correspondence table with the address of the next-stage repeater that is the next relay destination as viewed from the information mediating device; and, by referring to the correspondence table, stores the received information in the next Transmission control means for transmitting to the next-stage repeater; and when an abnormality occurs in the next-stage repeater recorded in the correspondence table, the address of the next-stage repeater in the correspondence table is replaced with the next-stage repeater. The second alternative to vessels An information mediating device comprising: an address rewriting means for rewriting to an address of a next-stage repeater. 2. The second next-stage repeater, when an error occurs in the next-stage repeater whose address is recorded in the correspondence table before the correspondence table is rewritten by the address rewriting means, 2. The information relay device according to claim 1, wherein the relay device is a relay device prepared in advance so as to play the role of a next-stage relay device.