JPH0575623A - Network system - Google Patents

Abstract

PURPOSE:To select a management equipment quickly able to provide a shortest route even when a termination equipment side does not store routing information. CONSTITUTION:A multiple address communication packet sent from each management equipment is given to a management address extract section 6 via a termination equipment reception section 2 and a packet processing section 4. The management address extract section 6 extracts an address of each management equipment from each packet and stores it to a management address storage section 8. When a packet is sent from a termination equipment, the packet processing section 4 obtains each address in the management address storage section via a route request section 9 and outputs a request in routing information to the management equipment via a transmission section 10. When routing information is sent from each management equipment to the termination equipment in response thereto, a route selection section 5 obtains the shortest route to the destination based thereon. The packet processing section 4 requests the relay of the packet to the management equipment providing a shortest route.

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. 4, 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]

In the present invention, the terminating device is provided with an extracting means, a storing means, a requesting means and a selecting means, and the extracting means is sent from each management device. When receiving the broadcast communication data of, the addresses of the respective senders, that is, the addresses of the management devices are respectively extracted from the broadcast communication data, and the addresses of the management devices are stored in the storage means. When sending the data to the network, the requesting means requests routing information to each management device based on the address of each management device in the storage means, and the selecting means selects each management device by the requesting means. Requesting relay of the data from each of the management devices based on the respective routing information from each of the management devices obtained as a result of the request for It is to select a physical device.

[0011]

According to the present invention, the address of each management device extracted by the extraction device is stored in the storage device, and when the data is transmitted to the network, the request device causes each management device having each address to be transmitted. The routing information is requested to the management device, and the selection unit selects the management device to which the data relay is requested, based on the routing information from each management device obtained as a result of the request. 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 terminating device requests the routing information from each management device, it is possible to quickly obtain each routing information from each management device, so that it does not take time to transmit the data. Complete.

[0012]

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

FIG. 1 is a block diagram showing a terminating device to which an embodiment of a network system according to the present invention is applied. The terminating equipment of this embodiment is the terminating equipment E11, E12, E in the network system shown in FIG.
It is applicable to any of 21, E22 and E31.

In FIG. 1, the reception address storage unit 1 stores an address indicating the terminating device and an address indicating broadcast communication.

The receiver 2 is connected to the network 3 and is for taking in packets on the network 3. When the receiving unit 2 fetches the packet, the receiving address storage unit 1 determines the destination address included in the packet.
Match each address in. 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 therefore the reception unit 2 sends the packet to the packet processing unit. Give to 4. If the destination address included in the packet does not match any of the addresses in the reception address storage unit 1, this packet is not addressed to the terminating device, and the reception unit 2 discards the packet.

The packet processing unit 4 is for processing a given packet. For a packet including an address indicating the terminating device as a destination address, first, whether the packet includes routing information or not. If the packet does not include routing information, the packet is subjected to appropriate processing, and if the packet does include routing information, the packet is given to the route selection unit 5. 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. If the packet includes routing information, the packet is given to the management address extracting unit 6.

When the route selecting unit 5 receives a packet including the address indicating the terminating device as the destination address and the routing information from the packet processing unit 4, it selects one route from the routing information and provides this route. The address of the management device to be operated, that is, the address indicating the transmission source included in the packet is stored in the route storage unit 7, and this address is returned to the packet processing unit 4.

When the management address extraction unit 6 receives from the packet processing unit 4 a packet including an address indicating broadcast communication as a destination address and routing information, the source address included in this packet, that is, the management device. Is extracted and the address of this management device is stored in the management address storage unit 8.

The route request unit 9 is instructed by the packet processing unit 4 to search the address of the management device, and in response to this, searches the address in the management address storage unit 8 and returns this address to the packet processing unit 4.

The transmitter 10 receives a packet to be transmitted from the packet processor 4 and sends this packet to the network 3.

In the terminating device having such a structure, if the terminating device is, for example, the terminating device E11 shown in FIG. 4, a packet containing routing information is periodically sent from each management device R11, R12 to the network A. The processing of the flowchart shown in FIG. 2 is carried out each time it is sent out. 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 receiving unit 2 in the terminating device E11 takes in the broadcast packet from the network A (step 10).
1) It is determined whether or not the destination address included in this broadcast packet matches any one of the addresses in the reception address storage unit 1 (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 device 4. If the destination address included in the packet does not match any of the addresses in the reception address storage unit 1 (step 102, NO), the packet is discarded (step 103) and the processing ends. Become.

Upon receiving the broadcast packet, the packet processing unit 4 confirms that the broadcast communication address is included (step 104, YES) and also confirms that the routing information is included (step 1).
05, YES), and thereafter, the broadcast packet is given to the management address extracting unit 6. If the broadcast communication address is not included (step 104, NO) or the routing information is not included (step 105, N).
O), other processing is performed on this packet (step 106).

When the management address extraction unit 6 receives the broadcast packet, the management address extraction unit 6 extracts the address of the management device R11 included in the packet as the source address (step 107) and stores this address in the management address storage unit 8. (Step 108).

When the broadcast packet is sent from the management device R12 to the network A, the same process is carried out, and the address of the management device R12 is stored in the management address storage section 8.

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 management address storage unit 8. I have to.

Thus, the management device indicated by the address stored in the management address storage unit 8 can relay the packet from the terminal device E11 connected to the network A to the terminal device connected to another network. Is. That is, here, the management devices capable of relaying packets from the termination device E11 to the termination device connected to another network are the management devices R11 and R12, and the addresses of these management devices R11 and R12 are the management addresses. It will be stored in the storage unit 8.

The logical configuration of the network system shown in FIG. 4 changes from time to time, and therefore the packet from the terminating device E11 connected to the network A to the terminating device connected to another network is relayed. Since the management device that can be used also changes, the address is erased from the management address storage unit 8 when a certain period, which is the broadcast packet transmission cycle, has elapsed from the time when the address was stored in the management address storage unit 8. As a result, the management address storage unit 8 does not store the address of the management apparatus that cannot relay the packet due to the change in the logical configuration of the network system, and the address of the management apparatus that can relay the packet. Only will be remembered.

Next, in a state where the addresses of the management devices R11 and R12 are stored in the management address storage unit 8,
A processing procedure for transmitting a packet from the terminating device E11 connected to the network A 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 the packet processing unit 4 in the terminating device E11 makes a request to send a packet addressed to another terminating device E21 (step 201), the address of the management device providing 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 route storage unit 7 (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 route storage unit 7 (step 202, NO), the packet processing unit 4 issues a route search request for the address. Instruct part 9 In response to this, the route request unit 9 causes each management device R to
The addresses 11 and R12 are read from the management address storage unit 8 and these addresses are returned to the packet processing unit 4 (step 203).

The packet processing unit 4 includes management devices R11 and R12.
A packet including the address of 1 and requesting routing information is formed, and this packet is sent to the network A via the transmission unit 10 (step 204).

When the management devices R11 and R12 receive the packet sent from the terminating device E11 to the network A (step 301, YES), it is confirmed that the address of each management device is included in the packet as the destination address. Check. Then, in order to respond to the request for the routing information by this packet, the source address included in the packet, that is, the address of the terminal device E11 is extracted, and the address of this terminal device E11 is included as the destination address,
A packet including the routing information is formed, and this packet is sent to the network A (step 30).
2). From each management device R11, R12 to the network A
Although each packet transmitted to the router includes routing information, it does not include an address indicating broadcast communication, and thus is not a broadcast packet.

The receiving unit 2 in the terminating device E11 sequentially takes in the respective packets from the respective managing devices R11 and R12, and the destination addresses included in these packets, that is, the addresses of the terminating devices are stored in the receiving address storage unit 1. After confirming that they match any of the addresses, these packets are sequentially given to the packet processing unit 4. Since the packet processing unit 4 includes an address indicating the termination device as a destination address and also includes routing information, the packet processing unit 4 includes these packets in the route selection unit 5
Give to. The route selection unit 5 obtains the shortest route to the network B to which the destination terminating device E21 is connected based on the routing information included in each packet, and determines the source address from the packet including the routing information indicating this shortest route. Extract. Here, the destination terminating device E
Since the management device that can provide the shortest route to the network B to which 21 is connected is the management device R11, the packet including the routing information indicating the shortest route is the packet from the management device R11. The included source address is the address of the management device R11.
The route selection unit 5 stores the address of the management device R11 in the route storage unit 7 as the address of the management device that provides the shortest route to the destination terminating device E21 (step 2).
05), this address is returned to the packet processing unit 4.

Upon receiving the address of the management device R11, the packet processing unit 4 includes the address of the management device R11.
In addition, 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 10 (step 206).

Since this packet contains the address of the management device R11, it is received by the management device R11. Management device R
11 sends the packet to network B by the shortest route (step 303). The terminating device E21 confirms that the address of the terminating device is included as the destination address, and takes in this packet.

When the packet addressed to the terminating device E21 is to be retransmitted, the processing from step 201 is repeated, but in step 202 the management device that provides the shortest route to the terminating device E21 of the destination. Since it is determined that the address of the management device R11 is already stored in the route storage unit 7 as the address of the
3 to 205 are omitted, and step 207 is performed instead. In step 207, the packet processing unit 4 reads the address of the management device R11 from the route storage unit 7, and forms 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 transmission unit 10 (step 206).

In this case, since the logical configuration of the network system changes from time to time, the management device R11 may not provide the shortest route. In such a case, the management device R11 notifies the terminating device E11 to that effect, and in response to this, the address of the management device R11 in the route storage unit 7 may be erased.

The addresses of the respective management devices capable of relaying packets are stored in the management address storage unit 8 in this way, and when transmitting a packet, routing information is stored based on the addresses of the respective management devices. The management device is requested, the shortest route is obtained from the routing information obtained thereby, and the management device that can provide this shortest route is requested to relay. That is,
When a packet is transmitted, the routing information is immediately acquired by a request to the management device rather than waiting for the periodic reception of a broadcast packet, so that the packet can be transmitted promptly. 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.

[0039]

As described above, according to the present invention, the address of each management device is stored, and when sending data to the network, routing information is sent to each management device having these addresses. Request, and based on each routing information from each management device obtained as a result of this request, to select the management device to request data relay, it is not necessary to store the routing information, Instead, only the address of each management device is stored, so the storage area can be small. Further, the respective routing information from each management device can be promptly obtained, so that the waiting time before transmitting the data does not become long.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a broadcast packet reception process performed by the terminating device shown in FIG.

FIG. 3 is a flowchart showing packet relay processing performed by the terminating device and the management device shown in FIG.

FIG. 4 is a diagram exemplifying a logical configuration of a network system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Received address storage part, 2 ... Reception part, 3 ... Network, 4 ... Packet processing part, 5 ... Route selection part, 6 ... Management address extraction part, 7 ... Route storage part, 8 ... Management address storage part, 9 ... Route request unit, 10 ... 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 terminating device receives respective broadcast communication data transmitted from each of the management devices, and outputs the broadcast communication data to the broadcast communication data. Extraction means for extracting the address of each management device included therein, storage means for storing the address of each management device, and when sending data to the network, Requesting means for requesting routing information to each management device based on the address; Based on the respective routing information from the respective management device obtained as a result of seeking a network system including a selection means for selecting a management device for requesting to relay the data from one of the respective management device.