JPH0575618A - Network system - Google Patents

Abstract

PURPOSE:To select a management equipment quickly able to provide a shortest route for data communication among management equipments even when a termination equipment side not store routing information. CONSTITUTION:Each packet subjected to multiple address communication from each management equipment is respectively given to a management address extract section 26 via a reception section 22 and a packet processing section 24 of a terminator. The management address extract section 26 extracts an address of each management equipment from each packet and stores it to a 1st management address storage section 27. In the case of sending a packet, the packet processing section 24 selects any of addresses in the 1st management address storage section 27 and sends a packet via a transmission section 29 to make a relay request to a management equipment of the selected address. The management equipment receives the packet and transfers the packet to a destination for the purpose of relay.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system for communicating data, and more particularly to determining a communication route in the network system.

[0002]

2. Description of the Related Art A network system of this type has a logical configuration as shown in FIG. 5, for example. In the figure,
The terminal devices E11 and E12 are connected to the network A,
Each terminal device E21, E22 is connected to the network B,
A terminating device E31 is connected to the network C. Further, the management device R11 is connected to the network A and the network B, and connects these networks with the shortest route. Further, the management device R12 is connected to the network A and the network C and connects these networks with each other by the shortest route.

Here, when data is to be communicated from the terminating device E11 to the terminating device E21, for example, the terminating device E11 is used.
Requests the relay to the management device R11 that connects the networks A and B by the shortest route, and transmits the data to the terminal device E21 through the management device R11.

In order to communicate data by the shortest route in this way, the terminating device stores each shortest route from the network to which the device is connected to each other network, and the other terminating device of the destination is stored. The shortest route is appropriately selected according to the above, and the relay of the data is requested to the management device that provides the selected shortest route. The shortest route between the networks is obtained on the management device side, and is broadcast from the management device to each terminating device as routing information. Further, since the logical configuration of the network system is not permanent and changes from time to time, the routing information is updated one by one and broadcasted periodically. Therefore, each terminating device receives the routing information at regular intervals and stores and manages the latest routing information.

However, when the scale of the network system is expanded or complicated, the information amount of the routing information becomes very large. Therefore, a storage area for storing the routing information is secured in the terminal device. Will be difficult to do.

Therefore, a routing information management processing system has been proposed in which a required route is extracted from the routing information sent from the management device by a terminating device, and only the extracted route is stored and managed (Japanese Patent Laid-Open No. HEI 2). -143
746).

However, here, if an accurate route is not stored, the terminating device waits for the periodical reception of the routing information, so that there is a drawback that it takes time until the data is transmitted.

[0008]

As described above, in the conventional network system, when the scale of the network system is expanded or complicated, the amount of routing information becomes very large. There is a problem in that it is difficult for the terminal device to secure a storage area for storing the. Further, Japanese Laid-Open Patent Publication No. 2-143746 discloses a technique in which only a necessary route extracted from routing information is stored on the terminating device side. However, if an accurate route is not stored here, the terminating device is not stored. Has a drawback that it takes a long time to transmit data because it waits for periodic reception of routing information.

Therefore, the present invention provides a network system capable of promptly selecting a management device that can provide the shortest route of data communication from each management device without storing routing information on the terminating device side. The purpose is to provide.

[0010]

According to the present invention, the management device is provided with a judging means and a notifying means, respectively, and when the data sent from the terminating device is relayed by the management device, The determination means determines whether or not there is another management device that can provide another route shorter than the data relay route, and if it is determined that there is another corresponding management device, the notification means Is configured to notify the terminal device of the address of the other management device. on the other hand,
The terminating device has an extracting means, a first storing means, and a second storing means.
Storage means and requesting means, and when the respective broadcast communication data sent from the respective management devices are received, the extracting means uses the broadcast communication data to determine the address of each sender. That is, the addresses of the respective management devices are extracted, these addresses are stored in the first storage means, and the addresses notified by the notification means are stored in the second storage means. When sending the data, the requesting means selects one of the addresses stored in the first storage means and the second storage means, and outputs the data to the management device having the selected address. I try to request data relay.

[0011]

According to the present invention, the addresses of the respective management devices are stored in the first storage means and the second storage means of the terminal device, and the requesting means is the first storage means and the second storage means. Any one of the addresses in the storage means is selected, and the management device having the selected address is requested to relay the data. Therefore, the terminating device only stores and manages the address of each management device, and the storage area for this purpose is obviously smaller than the area for storing the routing information. Further, since the relay of data is requested to the management device having the address selected from the addresses, it does not take time to transmit the data.

[0012]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows a management device to which an embodiment of the network system according to the present invention is applied, and FIG. 2 shows a terminating device to which an embodiment of the network system according to the present invention is applied. There is. The management device of this embodiment is applied to each of the management devices R11 and R12 in the network system shown in FIG. 5, and the termination device of this embodiment is the termination device E11 in the network system shown in FIG. , E12, E21, E22, E31
It can be applied to any of.

In the management apparatus shown in FIG. 1, the relay unit 1
Reference numeral 1 is connected to each of the networks 12 and 13, and is for transmitting / receiving packets to / from these networks.

Routing information is stored in the routing table 14, and this routing information is the shortest route for relay provided by the management device.
That is, the route between the networks 12 and 13 and the shortest route for relay provided by another management device are shown.

The control unit 15 is for controlling the management device, and includes a shortest route determination unit 16 and a route notification unit 17.

Note that the logical configuration of the network system shown in FIG. 5 changes from time to time, and therefore the respective shortest routes that can be provided by each management device also change, so that the logical configuration of the network system changes each time. , The respective routing information indicating the respective shortest routes is transmitted and received between the management devices, and the routing information in the routing table of each management device is updated accordingly.

Next, in the terminating device shown in FIG. 2, the reception address storage unit 21 stores the address indicating the terminating device and the address indicating the broadcast communication.

The receiving unit 22 is connected to the network 23 and is for taking in packets on the network 23. When receiving the packet, the receiving unit 22 compares the destination address included in the packet with each address in the received address storage unit 21. Here, if the destination address included in the packet matches any one of the addresses in the reception address storage unit 1, the packet is addressed to the terminating device, and the reception unit 22 sends the packet to the packet processing unit. Give to 24. In addition, the destination address included in the packet is the reception address storage unit 21.
If it does not match any of the addresses in the packet, the packet is not addressed to the terminating device, and the receiving unit 22 discards the packet.

The packet processing unit 24 is for processing a given packet. For a packet including an address indicating the terminating device as a destination address, it is first determined whether or not the packet includes routing information. If the routing information is not included, appropriate processing is performed on the packet, and if the routing information is included, the packet is given to the address determination unit 25. Also, for a packet that includes an address indicating broadcast communication as a destination address, it is first determined whether the packet includes routing information. If the packet does not include routing information, an appropriate packet is selected for the packet. When the routing information is included in the processing, the packet is given to the management address extracting unit 26.

When the management address extraction unit 26 receives a packet including an address indicating broadcast communication as a destination address and also includes routing information from the packet processing unit 24, the address of the transmission source included in this packet, that is, the management device. Is stored in the first management address storage unit 27.

When the packet processing unit 24 receives a packet including the address indicating the terminating device as the destination address and the routing information, the address determination unit 25 receives the address of the management device that provides the route indicated by the routing information. And stores the address of this management device in the second management address storage unit 28.

The transmitting unit 29 receives a packet to be transmitted from the packet processing unit 24 and sends this packet to the network 23.

In the terminating device having such a structure, if the terminating device is, for example, the terminating device E11 shown in FIG. 5, a packet containing routing information is periodically sent from each management device R11, R12 to the network A. Each time it is sent out, the processing of the flowchart shown in FIG. 3 is performed. It should be noted that this periodically transmitted packet is broadcast to all of the terminating devices connected to the network A, and includes an address indicating the broadcast communication as a destination address. Hereinafter, it is referred to as a broadcast packet.

First, if a broadcast packet is sent from the management device R11 to the network A, the receiver 22 in the terminating device E11 takes in the broadcast packet from the network A (step 10).
1) It is determined whether the destination address included in this broadcast packet matches any one of the addresses in the reception address storage unit 21 (step 10).
2). Here, since the address indicating the broadcast communication is included in the broadcast packet as the destination address, it is determined that they match (step 102, YES), and this broadcast packet is given to the packet processing unit 24. If the destination address included in the packet does not match any of the addresses in the reception address storage unit 21 (step 102, NO), the packet is discarded (step 103) and the processing ends. Become.

Upon receiving the broadcast packet, the packet processing unit 24 confirms that the broadcast communication address is included (step 104, YES) and also confirms that the routing information is included (step 105, YES), and thereafter, the broadcast packet is given to the management address extraction unit 26. If the broadcast address is not included (step 104, NO),
If the routing information is not included (step 10)
5, NO), other processing is performed on this packet (step 106).

When the management address extraction unit 26 receives the broadcast packet, the management address extraction unit 26 extracts the address of the management device R11 included in this packet as the source address (step 107), and uses this address as the first management address storage unit 27. (Step 108).

The same process is performed when a broadcast packet is sent from the management device R12 to the network A, whereby the address of the management device R12 is stored in the first management address storage unit 27.

When the broadcast packet from the management device is thus received, the routing information included in this packet is not stored at all, and only the address of the management device included in this packet is stored in the first management address storage unit 27. I try to remember.

In this way, the management device indicated by the address stored in the first management address storage unit 27 relays the packet from the termination device E11 connected to the network A to the termination device connected to another network. It is possible. That is, here, the management devices capable of relaying packets from the terminating device E11 to the terminating device connected to another network are the management devices R11 and R12, and the addresses of these management devices R11 and R12 are the first. Will be stored in the management address storage unit 27.

Note that the logical configuration of the network system shown in FIG. 5 changes at any time, so that packets from the terminating device E11 connected to the network A to the terminating device connected to another network are relayed. Since the management device that can be used is also changed, the address is deleted from the first management address storage unit 27 after a certain period of the broadcast packet transmission cycle has elapsed from the time when the address was stored in the first management address storage unit 27. To do it. As a result, the first management address storage unit 27 does not store the address of the management device that cannot relay the packet due to the change in the logical configuration of the network system, and manages the packet relay. Only the device address will be stored.

Next, in a state where the addresses of the management devices R11 and R12 are stored in the first management address storage unit 27, the terminating device E11 connected to the network A is used.
A processing procedure for transmitting a packet from a packet to a terminating device connected to another network will be described with reference to the flowchart shown in FIG. The destination terminating device is the terminating device E21 connected to the network B.

First, when a request for transmitting a packet addressed to another terminating device E21 is issued (step 201), the packet processing unit 24 in the terminating device E11 determines that the address of the management device that provides the shortest route to the terminating device E21 of the destination is determined. It is determined whether or not it is already stored in the second management address storage unit 28 (step 202). Here, since the address of the management device that provides the shortest route to the destination terminating device E21 is not stored in the second management address storage unit 28 (step 202, NO), the packet processing unit 24 uses the first One of the addresses of the management devices R11 and R12 in the management address storage unit 27 is read (step 203).

Here, it is assumed that the read address is the address of the management device R12 and the address of the management device R12 that cannot provide the shortest route from the terminal device E11 to the destination terminal device E21. ..

When the packet processing unit 24 reads the address of the management device R12, it includes the address of this management device R12,
Further, a packet addressed to the terminating device E21 in the network B is formed, and this packet is sent to the network A via the transmitter 29 (step 204).

In the management device R12, the relay unit 11 fetches the packet, and the relay unit 11 determines whether or not the packet includes an address indicating the management device. Here, if this address is included, this packet has been requested to be relayed to the management device, and therefore is passed from the relay unit 11 to the control unit 15 (step 30).
1, YES). If this address is not included, this packet has not been requested to be relayed to the management device (step 301, NO), and is not processed at all.

Upon receiving the packet from the relay unit 11, the control unit 15 extracts the destination data indicating the terminating device E21 in the network B from the packet, and obtains the route to this destination based on the routing information in the routing table 14. (Step 302). Here, the route from the management device to the terminating device E21 in the network B is that the packet is once delivered to another management device R11 and the packet is sent from the other management device R11 to the network B. Will be required.

Next, the shortest route determination unit 16 is activated,
The shortest route determination unit 16 determines whether or not the route obtained in step 302 is the shortest route (step 303). That is, the source data and the destination data are extracted from the packet, and the shortest route from the source network A indicated by the source data to the destination network B indicated by the destination data is determined based on the routing information in the routing table 14. Asked,
It is determined whether or not this shortest route matches the route obtained in step 302. Here, the shortest route is the route from the network A to the network B via the other management device R11, and the route obtained in step 302 once passes the packet to the other management device R11, and then the packet is passed to another management device R11. Since the route is sent from the management device R11 to the network B, that is, the route from the network A to the network B via the management device R12 and another management device R11, the shortest route is the route obtained in step 302. Is determined not to match (NO in step 303). In this case, the route notification unit 17 is activated.

The route notification unit 17 forms the routing information indicating the shortest route from the network A to the network B via the other management device R11, and also includes the source address included in the packet from the terminating device E11.
That is, the address of the terminating device E11 is extracted, a packet including the address of the terminating device E11 as a destination address and routing information is formed, and the packet is transmitted to the network A (step 304).

After this, the control unit 15 causes the step 302 to proceed.
In order to relay the packet from the terminating device E11 through the route obtained in step 1, this packet is sent from the relay unit 11 to the network A and transferred to another management device R11. Upon receiving the packet, the other management device R11 sends the packet to the network B. The destination terminating device E21 confirms that the address of the terminating device is included as the destination address, and fetches this packet.

When it is determined in step 303 that the shortest route matches the route obtained in step 302, the process jumps to step 304 and ends.

On the other hand, the reception unit 22 in the transmission source terminating device E11 takes in the packet from the management device R12, and the destination address included in this packet, that is, the address of the terminating device is the address of each address in the reception address storage unit 21. After confirming that the packet matches any one of them, the packet is given to the packet processing unit 24.

Since the packet processing unit 24 includes the address indicating the terminating device as the destination address and the routing information, the packet processing unit 24 gives this packet to the address determination unit 25. When the address determination unit 25 receives the packet, it determines the address of the management device R11 based on the routing information included in this packet, that is, the routing information indicating the shortest route from the network A to the network B via another management device R11. Then, the address of the management device R11 is stored in the second management address storage unit 28 as the one that provides the shortest route (step 205).

The management device R12 requested to relay in this way
Although it cannot provide the shortest route, it relays the packet from the terminating device E11 by a route that it can provide and notifies the terminating device E11 of the routing information indicating the shortest route. Also, the terminating device E11
Calculates the address of the management device R11 that can provide the shortest route based on the routing information, and stores the address of the management device R11 in the second management address storage unit 28.

Further, when the packet addressed to the terminating device E21 is transmitted again, the processing from the step 201 is performed again, but in the step 202, the management device that provides the shortest route to the destination terminating device E21. Since it is determined that the address of the management device R11 is already stored in the second management address storage unit 28 as the address of the above, step 203 is omitted, and instead step 2
06 will be performed. In step 206, the packet processing unit 24 determines that the second management address storage unit 2
8 to read the address of the management device R11, and form a packet including the address of the management device R11 and addressed to the terminating device E21 in the network B. Then, this packet is sent to the network A via the transmitting unit 29 (step 204). This packet is relayed by the management device R11, transmitted to the network B, and captured by the terminating device E21.

Since the logical configuration of the network system changes from time to time, the management device R11 may no longer provide the shortest route. In such a case, the management device R11 notifies the terminating device E11 of the routing information providing the shortest route (steps 303 and 304). In response to this, the address in the second management address storage unit 28 is addressed. Should be updated (step 205). In this way, the addresses of the respective management devices capable of relaying the packet are stored in the first and second management address storage units 27 and 28, and when transmitting the packet, one of the addresses of the respective management devices is stored. Is selected and a relay is requested to the management device having the selected address. That is, when transmitting a packet, the packet is immediately transmitted to a management device that can perform relaying, instead of waiting for regular reception of a broadcast packet. Further, instead of the routing information, the address of each management device capable of relaying the packet is stored, so that the storage area for this can be small.

[0047]

As described above, according to the present invention, the address of each management device is stored, and when sending data to the network, one of these addresses is selected and selected. Since the management device having the different address is immediately requested to relay the data, it does not take time to transmit the data. Also, there is no need to store routing information, only the address of each management device is stored instead.
The storage area can be small.

[Brief description of drawings]

FIG. 1 is a block diagram showing a management device to which an embodiment of a network system according to the present invention is applied.

FIG. 2 is a block diagram showing a terminal device to which an embodiment of the network system according to the present invention is applied.

3 is a flowchart showing a broadcast packet reception process performed by the terminating device shown in FIG.

FIG. 4 is a flowchart showing a packet relay process performed by the management device shown in FIG. 1 and the terminating device shown in FIG.

FIG. 5 is a diagram exemplifying a logical configuration of a network system.

[Explanation of symbols]

11 ... Relay unit, 12, 13 ... Network, 14 ... Routing table, 15 ... Control unit, 16 ... Shortest route determination unit, 17 ... Route notification unit, 21 ... Received address storage unit, 22 ... Receiving unit, 23 ... Network, 24 ... Packet processing unit, 25 ... Address determination unit, 26 ... Management address extraction unit, 27 ... First management address storage unit, 28 ... Second
Management address storage unit, 29 ... Transmission unit.

Claims (1)

[Claims] 1. A plurality of terminating devices connected to a network and data transmitted and received between the respective terminating devices are relayed, and broadcast communication data in which a destination is a broadcast and a transmission source is its own address is provided. In a network system including a plurality of management devices for transmitting to a network, the management device, when relaying data transmitted from the terminating device, can provide another route shorter than the route of this relay. Determination means for determining whether or not there is a management device, and notifying means for notifying the termination device of the address of this other management device when it is determined by the determination means that there is another corresponding management device The terminating device receives each broadcast data sent from each of the management devices, and is included in each of the broadcast data. Extracting means for extracting the address of each management device, first storing means for storing the address of each management device extracted by the extracting means, and second storage means for storing the address notified by the notifying means. Storage means and when sending data to the network, one of the addresses stored in the first storage means and the second storage means is selected and the selected address is stored. A network system comprising: a requesting unit that requests the management device to relay the data.