JPH02143759A - Routing information update processing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] This invention relates to a routing information update processing method in a network system.

Aimed at reducing broadcast communication about routing information.

In a network system comprising a route management device that broadcasts and holds routing information, and a node that takes in and holds the broadcasted routing information and communicates based on the same, a request for updating the routing information is provided. The node is provided with an update request unit for issuing an update request, and the route management device and the node update the routing information held by each in response to the issue of the update request from the update request unit.

[Industrial application field]

The present invention relates to a routing information update processing method.

formula.

More specifically, the present invention relates to a routing information update processing method in a network system.

In a network system, when communicating between nodes, messages are transmitted based on routing information. This routing information is held at each node.

[Conventional technology]

To communicate between each node that makes up the network,
It is necessary to know whether the destination node is connected to the network and whether it is in a state where it can receive data. Additionally, if the source node is not connected to the network, it is necessary to request connection.

Therefore, such information (hereinafter referred to as connection information) is combined into a single piece of information (hereinafter referred to as routing information) that indicates the logical configuration of the network at that time, and furthermore, this information is sequentially updated to the latest configuration. It is necessary to update as shown.

For this purpose, there is a device (hereinafter referred to as
A route management device) is provided. The route management device creates routing information based on connection information sent from each node making up the network, and broadcasts this to each node at regular intervals.

Each node takes in the broadcast data (routing information) according to the processing flow shown in FIG.

■ Obtain packets on the transmission path.

■ Perform CRC (cyclic redundancy) on the acquired information axis.
dancycheck) Sequentially sends the data to the arithmetic circuit and performs an error check.

■ If there is an error, perform error processing.

■ Check whether the information has been broadcast.

■ If the packet is not broadcast, extract the address information from the packet and compare it with the own address.

■ If the two are not the same, the transmission is not to your own station, so
Do not retrieve data.

■ If it has been broadcast, and if the two are the same, processing is performed according to the protocol and the data is acquired. That is, if the data is broadcast, the data is considered as routing information.

Nodes that obtain routing information in this way store it in their routing tables.

When it becomes necessary to send a message, the sender node determines the connection status and whether or not the message can be sent from its own routing table, and performs the sending process. Therefore, the routing information held at each node is , must always be up-to-date.

[Problem to be solved by the invention]

According to the prior art described above, in order to keep the routing information up-to-date, it is essential that the route management device broadcast the routing information to each node at regular intervals.

As a result, communication for maintaining the network increases, instead of the message communication between nodes that is originally desired.
There was a problem that network usage efficiency decreased. This is because the speed of network data transfer (communication) is constant.

This is because as the number of nodes connected to the network increases, the amount of routing information also increases, which increases communication time.

Furthermore, since the time for broadcasting is determined in advance, broadcasting is performed even though there is no change in the routing information, resulting in a problem of unnecessary communication.

The problems described above become more prominent as the network system becomes larger, or in other words, as the network system becomes more complex.

An object of the present invention is to provide a routing information update processing method that reduces broadcast communication regarding routing information.

[Means to solve the problem]

FIG. 1 is a diagram illustrating the principle of the present invention and shows a network system according to the present invention.

In FIG. 1, 1 is a route management device, 11 is a routing table, 2 is a transmission path, and 3 is a node.

31 is an update request section.

The route management device 1 broadcasts routing information to each node 3 (No to Nh) configuring the network, and holds the routing information in its own routing table 11. For this purpose, the route management device 1 creates (configures) routing information based on the connection information sent from each node N0 to N.

Update and manage network configuration and changes.

The routing table 11 is provided in the memory of the route management device 1 and the nodes 3 (N, to Ni), and stores routing information about the nodes N to N constituting the network system.

Node 3, that is, nodes N0 to N, has 9 other nodes N0
to N, when communicating.

Communication is performed based on the routing information held in its own routing table 11.

The update request unit 31 is provided in each of the nodes N, to N, and has learned that a state (update cause) has occurred in which routing information should be updated for either the node 3 to which it belongs or another node 3. At the same time, a request to update the routing information is issued.

This update request is notified to the route management device 1 or to the route management device 1 and all other nodes 3.

[Effect]

FIG. 2 is an explanatory diagram of the operation of the present invention, showing a processing flow for updating routing information. FIG. 3 is a diagram showing the state of this end-to-end communication.

Among the nodes N0 to Nh, the nodes and route management device 1 currently connected to the network are:

It holds routing information in its own routing table 11. The route management device 1 does not broadcast routing information at regular time intervals.

(2) A situation occurs in which routing information should be updated in one of the nodes 3 composing the network. The main cause of the update is the connection or disconnection between the node 3 and the network.

(2) For example, the update request unit 31 of node N, upon learning of the occurrence of the above state, issues an update request. If the above-mentioned state occurs at node N, the update requesting unit 31 can naturally know this because it has occurred at node N to which it belongs. Further, if the above-mentioned state occurs in a node other than node N, the update requesting unit 31 can know this when node N3 fails to communicate with the node. Therefore, one issued update request is information indicating what state has occurred in which node.

That is, it includes information instructing how to update the routing information.

(2) The update request unit 31 of the node N notifies the route management device 1 of an update request by single cast communication (dotted line (i) in FIG. 3(A)).

The route management device 1 that receives this updates the routing information in its own routing table 11 based on the update request.

(2) Since the route management device 1 has updated the routing information, it broadcasts the updated routing information to each node N (dotted line (ii) in FIG. 3(A)).

■ Each node N0 to N, including node N3.

When routing information is broadcast, it is taken in and the routing information held in its own routing table 11 is updated.

■ On the other hand, in the case (dotted line (i) in FIG. 3(B)) where the update request unit 31 of node N wants to notify the route management device 1 and all other nodes 3 of the update request by broadcast communication. The route management device 1 that received this
and node 3, respectively.

The routing information held in its own routing table 11 is updated.

As described above, it is possible to eliminate periodic broadcasting of routing information and to perform updating only when necessary. Due to this.

It is possible to reduce the proportion of communication regarding routing information to the total communication and improve network usage efficiency.

〔Example〕

FIG. 4 is a block diagram of an embodiment, showing a composite network.

Nodes N0 to Nb, nodes N and Nl, node N,
and N l 6 + and nodes N + t and Nlt are
Each connected by transmission line 2, forming a ring (or loop)
The first part of the mold is the second part of the ring (or loop) part.
Network, bus-type third network.

and a bus-type fourth network. Each network is connected to each other via the route management device 1 to form a composite network.

The route management device 1 consists of a router or a gateway. Therefore, the route management device 1 uses at least TCP/I
This is an interconnection device that connects a plurality of networks using the P protocol, and includes at least a protocol conversion function (transmission rate, packet size conversion) and a routing function.

The route management device 1 includes a routing table 11,
Broadcasts routing information to a predetermined (white side: to which it is connected) network. for example,
The route management device R0 is the first one on the eye side. The routing information about the second network is transferred to the first network. Broadcast to the second network. By incorporating this as one node, the route management devices R1 and R2 have routing information of the second network to which they are not connected. By doing this appropriately, each route management device R0 to R2 always has the latest routing information for all nodes 3 and all route management devices xt in its routing table 11. Due to this.

It enables communication between nodes 3 of different networks.

Routing information in complex networks.

In addition to being connection information, it is also information for determining one communication path (route). That is, the node 3 first determines the network to which the destination node 3 is connected based on the destination node address, and then determines which route management device 1 should relay the data to in order to transmit data to that network. from the routing information. The source node 3 then transmits a message to the route management device l. The route management device 1 that has received the message searches for the destination node 3 or other route management device 1 from its own routing table 11 and transmits the message to these nodes. For example, node N
, to node N1□.

Communication is performed along the route N,→R0→R2→Nlz.

Therefore, the routing information includes necessary information about all nodes 3 and all route management devices 1. For this reason, as the network becomes more complex, the total number of nodes 3 and route management devices 1 increases to hundreds to thousands, and the time required to communicate routing information increases. Also, conversely, by limiting the communication time of routing information.

The total number of nodes 3 and route management devices l may be limited. The present invention solves these problems and facilitates network integration.

Next, processing for updating routing information will be explained for each major update cause.

(1) When connecting node 3 FIG. 5 shows the processing flow for updating routing information when connecting node 3 to a dual network.

FIG. 6 shows the state of communication at this time.

(2) For example, node N is connected to the network by turning on its power.

(2) The update request unit 31 of node N issues a request to update routing information. Then, the dotted line (
i) to the route management device 1, or to the route management device 1 as shown in FIG.
) to the route management device 1 and all other nodes 3 as indicated by the dotted line (i).

Notify update requests. Which notification is to be made can be determined in advance.

Note that at this point, node N does not have routing information, but the communication for the notification.

Since this is a broadcast communication that is a communication to the route management device 1 or a transmission to all connected nodes, it can be carried out without any problem.

(2) Upon receiving the update request, the route management device 1 performs connection confirmation communication for the node 3 in order to confirm the current (that is, the latest) connection status of the node 3 in the white network.

(2) Nodes 3 (including node N) connected to the network that have received the connection confirmation communication notify the route management device 1 that they are connected (connection information).

(2) The route management device 1 configures (creates) routing information based on the connection information sent from each node 3. That is, the routing information is updated to the latest information.

Therefore, the routing information is updated using the issuance of the latest request as a trigger.

■ The route management device 1 sends the updated routing information to all nodes 3 (including node N) of the white network.
(The dotted line in Figure 3 (A)
ii)). This broadcast is performed once regardless of what kind of notification was given in process (2).

■ All nodes 3 (including node N) connected to the network take in the broadcasted routing information and update their routing information accordingly.

According to the above process, using the issuance of an update request as a trigger,
A node that issued an update request earlier but was not accepted correctly due to a failure on transmission path 2,
Correct and up-to-date routing information can be obtained even for nodes that go down before issuing an update request.

On the other hand, if the update request is broadcast in process (2) and the route management device 1 and node 3 individually update the routing information (if there are no processes (2) and (2)), the routing information will be updated based on the update request. Note that in this case, since the node N3 does not have any routing information as it is, after the process ①, the route management device 1
request to send routing information. Upon receiving this, the route management device 1 transmits the request to the node N that made the transmission request.
, (dotted line (ii) in FIG. 6).

(2) When node 3 is disconnected FIG. 7 shows the processing flow for updating routing information when node 3 is disconnected from the network.

(2) For example, assume that node N is disconnected from the network due to its power being cut off or the like.

Prior to disconnection, the update request unit 31 of node N issues a request to update routing information. And Figure 3 (
Notify the update request to the route management device 1 as shown in dotted line (i) in A), or to the route management device 1 and all other nodes 3 as shown in dotted line (i) in FIG. 3(B). do.

After this node N, its T! , due to disconnection of the source, etc.

You are disconnected from the network.

(2) Upon receiving the update request, the route management device W1 performs connection confirmation communication for the node 3 in order to confirm the current (ie, latest) connection status of the node 3 in the white network.

Node 3 connected to the network that received the connection confirmation communication
notifies the route management device 1 that it is being connected (connection information).

(2) The route management device 1 configures (creates) routing information based on the connection information sent from each node 3. That is, the routing information is updated to the latest information.

(2) The route management device 1 broadcasts the updated routing information to all nodes 3 of the white network (dotted line (ii) in FIG. 3(A)).

All nodes 3 connected to the network take in the broadcasted routing information.

This updates the routing information.

Note that even if the update request is broadcast in process (2) and the route management device l and node 3 individually update the routing information (at least when there is no process (2)), node N3 is disconnected, so the sixth Processing as shown in the figure is not necessary.

(3) When Communication Fails (Part 1) FIG. 8 shows a processing flow for updating routing information when communication with another node fails (when a collision error occurs). FIG. 9 shows the state of communication at this time.

■ In normal message communication between nodes 3, as shown in FIG. 9, node 2, for example, node N, sends a message to node N6. This is done by sending a response to node N (dotted line (ii) in FIG. 9). That is, if there is this response, it means that the 8th communication was successful.

However, if node N goes down without making an update request, for example, the routing information is not updated and node N is supposed to be normally connected to the network. Therefore.

Node N, communicates with node N.

The response cannot be obtained (dotted line (iii) in FIG. 9).

That is, one communication fails.

(2) The update request unit 31 of the node N, which has learned of the failure in communication with the node N, issues a request to update the routing information. Then, for the route management device 1 as shown by the dotted line (i) in FIG. 3(A), or for the route management device 1 and all other nodes 3 as shown by the dotted line (i) in FIG. 3(CB). ,
Notify update requests.

Thereafter, processes ① to ② are performed in the same way as processes ② to ② in FIG. 5 described above.

In this way, when the destination node 3 is down and there is no response, the source node 3 can detect an abnormality in the destination node 3 by timeout of the response time. This enables rapid network reconstruction (routing information update).

(4) When communication fails (Part 2) Even though node N6 is normally connected to the network, node N cannot receive a response due to, for example, node N failing to obtain a message. (dotted line (ij) in Figure 9).

In this case, the update request unit 31 of node N issues an update request as shown in process (2) in FIG. 8, and as a result of the series of processes shown in FIG. Put it away.

Therefore, in order to prevent this, one of the primary processes is performed.

(a) In FIG. 8 (■), when the update request unit 31 of the node N broadcasts an update request to the route management device 1 and all other nodes 3, the node N6 can also know this. There, node N learns that there is an erroneous update request for itself.

causes the update request unit 31 to broadcast a correct update request or cancellation of the previous update request to the route management device 1 and all other nodes 3.

(b) As a result of process (2) in FIG. Reflect it in the figure processing ■. If updating the routing information is not necessary as a result, step 5 of FIG. 8 is omitted.

(1) As a result of process (2) in FIG. 8, node N can learn that its own routing information is incorrect. Therefore, the node N6 causes its update request unit 31 to notify the correct update request to the route management device 1, or to the route management device 1 and all other nodes 3. Due to this.

A series of processes shown in FIG. 5 are performed.

In addition, in the above, the first network (the same applies to the 32nd network), which is a ring type (or loop type), was explained, but in the fourth (and second) network, which is a bus type, The same thing is possible.

That is, the notification of the update request in the process (2) in FIG. 5, the process (2) in FIG. 7, and the process (2) in FIG. 8 is sent from one node 3 (for example, N1. For route management device 1 (R2) (dotted line (i)) or for route management device 1 and other nodes 3 (dotted line (ii))
It will be done.

In addition, the discovery of the collision error that is the cause of the update (processing ■ in Figure 8) is performed at node N as shown in Figure 10 (B).
This is known by the fact that no response (dotted line (ii)) is obtained from node N12 to the message sent from node N13 to another node 3 (for example, N18) (dotted line (I)).

In addition, if the node Nlff that issued the update request needs to separately perform processing to obtain routing information (as shown in FIG. 6), as shown in FIG. 1 to request routing information (dotted line (i)).

The route management device 1 that receives this transmits the routing information to the node N13 (dotted line (ii)).

Broadcasting of the routing information from the route management device 1 in the process (1) in FIG. 5, the process (2) in FIG. 7, and the process (2) in FIG. 8 is performed as shown in FIG. 1O (D).

〔Effect of the invention〕

As explained above, according to one aspect of the present invention, in the routing information update processing in a network system, by updating the routing information only when necessary, it is possible to eliminate the periodic broadcasting of the routing information. This makes it possible to reduce the proportion of communication regarding routing information (communication for maintaining the network) in the total communication, improve network usage efficiency, and reduce the number of nodes and route management devices that can be connected to the network. The number can be increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of the present invention. FIG. 2 is an explanatory diagram of the operation of the present invention. FIG. 3 is a diagram showing the state of communication. FIG. 4 is a configuration diagram of an embodiment. FIG. 5 is an update processing flow and FIG. 6 is a diagram showing the state of communication. FIGS. 7 and 8 are update processing flows. FIGS. 9 and 10 are diagrams showing the state of communication. FIG. 11 is an explanatory diagram of the prior art. 3 is a route management device, 11 is a routing table or transmission path, 3 is a node, and 31 is an update request unit. Patent applicant PFU Co., Ltd. Patent attorney Hiroshi Mori 1) (and 2 others) An explanatory diagram of the operation of the present invention A diagram illustrating the status of communication Figure 3: JR processing flow diagram Route management device update processing flow Figure 3 7 Figure 1 Figure 1 ■ Node (N3) Update processing flow 8 Figures (A) (B) Diagrams showing the state of communication Figure 10 (G7) (C) (D) Diagrams showing the state of communication Figure 10 ('>/12)

Claims (1)

[Scope of Claims] A route management device (1) that broadcasts and holds routing information, and a node (3) that takes in and holds the broadcasted routing information and communicates based on it. In the network system, an update request unit (31) for issuing an update request for the routing information is provided in the node (3), and the update request unit (31) issues an update request for the routing information.
31) A routing information update processing method characterized in that the route management device (1) and the node (3) update the routing information held by each in response to the issuance of the update request from the router.