JPH11234337A - Message relay system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively transfer a message from a substituting route even to an unfixed network without exchanging the message beforehand between nodes. SOLUTION: The respective nodes N2-N5 obtain via node information for indicating at least one of the nodes through which the message is already passed from the received message. Then, while limiting the transfer of the message to the node indicated by the via node information, the message is transferred in a transmission destination direction. At the time, in the case that message transfer in the transmission destination direction can not be suitably performed by a network fault or the like, the message is transferred in the transmission origin direction of the message.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a message relay system, a message relay method, a node device, and an information recording medium, and more particularly, to a technique for relaying a message by an alternative route as required when a plurality of message routes exist.

[0002]

2. Description of the Related Art Conventionally, in a message relay system in which a message is relayed at a plurality of nodes and links on a network (in this specification, these are simply referred to as "nodes" or "node devices"), a node failure occurs. Therefore, when the message transfer to the next node fails in each node, the message transfer is restarted after recovery from the failure, or the message is discarded or saved and the process ends with an error.

Therefore, according to the conventional technique, even when a plurality of message transfer paths exist from a message transmission source to a transmission destination, if a failure occurs in a certain link, the message transmitted from the transmission source is not transmitted. The link is discarded or saved, and the message relay ends in error. For this reason, there is a problem that the message is not successfully transferred to the destination even though the alternative route, that is, the detour route via the link exists separately.

[0004] In this regard, the detour route search system disclosed in Japanese Patent Application Laid-Open No. Hei 7-264184 discloses a technique for searching for a detour route for a fault location when a node or link in the network has a fault. According to this technique, a node that detects a failure such as a link sends a recovery message to surrounding nodes. Then, when the message reaches the node at the other end of the failure section, this node transfers the message to the node from which the recovery message was originally issued. In this way, the detour path to the fault location is detected by exchanging the recovery message.

[0005]

However, this technique has a problem in that useless data flows on a network because a transfer path is previously secured by exchanging restoration messages.

[0006] The above-mentioned technique may be effective for a fixed network having a plurality of routes.
In a non-fixed network such as the Internet, it is difficult to secure a transfer path in advance, and it is not desirable to apply the above-described conventional technology as it is to a non-fixed network such as the Internet.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to exchange a message effectively on an unfixed network without exchanging messages in advance between nodes. Message relay system, message relay method,
A node device and an information recording medium thereof are provided.

[0008]

According to a first aspect of the present invention, a plurality of nodes connected on a network include message source information, message destination information, and message content information. Receive the message,
The message is transferred to at least one of one or more other nodes existing in the direction of the destination of the message indicated by the message destination information, and the message content information included in the message is transferred to the message indicated by the message source information. A message relay system for transmitting from a transmission source to a message transmission destination indicated in the message transmission destination information, wherein each node obtains transit node information indicating at least one of nodes through which a received message has already passed. Information acquisition means, while restricting transfer of a received message to a node represented by the transit node information acquired by the transit node information acquisition means, in a direction of a message destination indicated in the message destination information; Messages received by any of the existing nodes Message forwarding means for sending, and, in a predetermined case, message backward sending means for forwarding the received message to a node existing in the direction of the source of the message indicated by the message source information included in the received message, Including.

[0009] In a second aspect based on the first aspect, each node further includes transit node information writing means for including information representing the own node in a message received as at least part of the transit node information, The information acquiring means is for reading, from the received message, the transit node information included in the message by the transit node information writing means of another node.

[0010] In a third aspect based on the second aspect, the transit node information included in the message is configured as list information representing at least a part of nodes that have already passed through the message, and the transit node information is written. The means adds information representing the own node to the via node information included in the received message.

In a fourth aspect based on any one of the first to third aspects, the message at least indicates whether or not an alternative route is connected to each of at least some nodes through which the message has passed. Each node further includes alternative route information, and when there are a plurality of nodes existing in the direction of the message destination indicated in the message destination information included in the received message, the own node is connected to the alternative route. The own node alternative route information adding means for adding information to the effect that the message is present to the alternative route information included in the message, wherein the message retransmission means includes a message indicated in the message source information based on the alternative route information. Among the nodes in the direction of the source of the message, it has been determined that the alternative route was not connected to the node through which the message has already passed. When the one that limits to forward the received message already nodes via.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the invention, in the predetermined case, the message forwarder cannot suitably forward the received message to any of the nodes. It is something that is.

According to a sixth aspect of the present invention, a plurality of nodes connected on a network receive a message including message source information, message destination information, and message content information, and receive a message indicated by the message destination information. Forwards to at least one of one or more other nodes existing in the direction of the destination, and indicates message content information included in the message from the message source indicated by the message source information to the message destination information. A message relay method for transmitting to a message transmission destination, wherein the received message is obtained in the via node information obtaining step of obtaining via node information representing at least one of the nodes that have already passed, and To the node represented by the transit node information Message forwarding step of forwarding a received message to any node existing in the direction of the message destination indicated in the message destination information while restricting the transfer of the received message, Each node performs a message retransmission step of transferring the received message to a node existing in the direction of the message transmission source indicated by the message transmission source information included in the message.

According to a seventh aspect of the present invention, there is provided a transit node information acquiring means for acquiring transit node information representing at least one of the node devices to which a received message has already passed, and the transit node acquired by the transit node information acquiring means. Message forwarding means for forwarding the received message to any node existing in the direction of the destination of the message indicated by the message destination information while restricting the transfer of the received message to the node represented by the information,
In a predetermined case, the message transmission means includes a message reverse transmission means for transferring the received message to a node device existing in the direction of the transmission source of the message indicated by the message transmission source information included in the received message.

In an eighth aspect, a plurality of node devices connected on a network receive a message including message source information, message destination information, and message content information, and are indicated by the message destination information. Transferring the message content information included in the message to at least one of one or more other node devices existing in the direction of the message transmission destination from the message transmission source indicated by the message transmission source information to the message transmission destination information An information recording medium storing a program for causing a computer to operate as a node device used in a message relay system for transmitting a message to a message destination indicated in (1), wherein the received message represents at least one of the node devices that has already passed. Get node information via node information Step and the transfer of the received message to the node represented by the transit node information acquired in the transit node information acquisition step, while restricting the transfer of the received message to the destination of the message indicated by the message destination information. A message forwarding step of transferring the received message to any of the nodes; and, in a predetermined case, the received message to a node device existing in the direction of the source of the message indicated by the message source information included in the received message. And a program for causing a computer to execute a message reverse transfer step of transferring the message.

[0016]

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

FIG. 1 is a diagram showing an overall configuration of a network to which a message relay system according to each embodiment described below is applied. As shown in FIG. 1, the network 10 includes nodes N1 to N6.
Here, the node N1 is connected to the node N2, and the nodes N3 and N4 are connected to the node N2. On the other hand, while the node N6 is connected to the node N5,
The nodes N3 and N4 are connected. That is, in the network 10, there are two shortest message transfer paths between the node N2 and the node N5, one via the node N3 and one via the node N4.

In the following, a description will be given of the relaying of a message in the network 10 shown in FIG. 1 in which the transmission source is the node N1 and the transmission destination is the node N6.

Embodiment 1 FIG. 2 is a diagram schematically illustrating a configuration of a message transmitted through the network 10 in the message relay system according to the first embodiment. As shown in the figure, the message includes a destination address 12 as message destination information, a source address 14 as message source information, and a message body 16 as message content information. ing. Here, the address of the node N6 is recorded in the destination address 12, and the node N6 is recorded in the source address 14.
It is assumed that address 1 is recorded.

FIG. 3 is a diagram showing a configuration of a node device used as nodes N2 to N5 of the network 10 in the message relay system according to the first embodiment. As shown in FIG. 1, the node device includes a transit node information acquisition unit 18, a message forwarding unit 20,
It is configured to include a message reverse transmission unit 22 and a connection node storage unit 24.

Here, the connection node storage unit 24 stores a table indicating to which of the other node devices connected to the node device the message should be transmitted to a certain destination. Is stored, and if an address is given as a search key, the address of the node device connected in the direction of the address is obtained. For example, in the connection node storage unit 24 in the node N2 in FIG. 1, if the addresses of the nodes N5 and N6 are given as search keys, the addresses of the nodes N3 and N4 can be obtained.

The transit node information acquiring unit 18 is means for acquiring transit node information indicating at least one of the nodes to which the received message has already passed. The transit node information acquiring unit 18 may acquire information on a node through which a message has already passed, based on information included in a received message, as in a message relay system according to each embodiment described later, for example. Alternatively, when establishing a call between nodes, the above-mentioned transit node information may be obtained separately from transmission and reception of a message.

When a message is received from another node device, the message forwarding unit 20 uses the destination address 12 included in the message as a search key and sends it from the connected node storage unit 24 to the destination direction (hereinafter, “transmission destination”). The address of the node device connected to the direction is acquired, and the message is transferred to any of the addresses. At this time, the message forwarding unit 20 restricts transfer of a message to the node device represented by the transit node information acquired by the transit node acquisition unit.

The message sending section 22 is connected from the connection node storage section 24 in the direction of the source address 14 (hereinafter referred to as “source direction”) using the source address 14 included in the received message as a search key. The address of the node device is acquired, and the message is transferred to any of the addresses. This message reverse transmission unit 22
Is performed when the received message has not been transferred normally due to a network failure or the like, despite the fact that the received message has been transferred to the node device existing in the destination direction by the message forwarding unit 20. The message transfer by the sending unit 20 may be performed when the message transfer cannot be performed suitably, such as when the message cannot be transferred at the expected transfer speed.

FIG. 4 is a flowchart for explaining the operation of the node device having the above configuration. As shown in the figure, when a message is received from another node device (S101), the node device acquires the transit node information by the transit node information acquisition unit 18 as described above (S10).
2). Next, the message forwarding unit 20 searches the connected node storage unit 24 for a node device to be transferred next using the destination address 12 included in the received message in S101 as a search key (S103). Then, when a node device to be transferred next is found, it is determined whether or not the node device is the same as the node device specified by the transit node information acquired in S102 (S104). Returning to S103, another node device is searched again. On the other hand, if it is determined that the node devices are not the same in S104, the received message is transferred to the node device searched in S103. Then, when the transfer is successful (S105), the processing in the node device ends. On the other hand, if the message transfer fails in S105, the process returns to S103 again to search for another node device.

In this way, the processing of S103 to S105 is repeated, and if the message transfer has failed for all of the other node devices connected in the direction of the destination, or if the same as the node device that has already passed, the next message is sent back. The source address 1 included in the received message by the unit 22
Then, a node device to be transferred next is searched from the connected node storage unit 24 using 4 as a search key (S106). That is,
Here, a node device for transferring the received message toward the transmission source is searched. Then, the message reversing unit 22 sends S1 to the node device searched in S106.
In step S107, the transfer of the message received in step S01 is attempted. If the transfer is successful (S107), the processing in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S108), and the processing in the node device ends.

According to the message relay system described above, for example, when a network failure occurs between the nodes N3 and N5 in the network 10 shown in FIG. 1, the message is transmitted from the node N1 and transferred to the node N3. The received message is transmitted from the node N3 to the node N5.
It is determined that transfer in the destination direction toward is impossible (S103 to S105), and transfer in the source direction is performed toward the node N2 (S106, S107). next,
In the node N2, if information indicating that the message has already passed through the node N3 has been acquired as the transit node information (S102), the message forwarding unit 20 restricts the transfer of the message to the node N3, and It forwards the received message to another node in the direction, node N4.

As described above, according to the message relay system, although a certain node device has forwarded a received message to a node device existing in the direction of the transmission destination, the transfer cannot be suitably performed. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

Embodiment 2 Next, a message relay system according to Embodiment 2 of the present invention will be described.

FIG. 5 is a diagram schematically showing a configuration of a message transmitted through the network 10 shown in FIG. 1 in the message relay system according to the second embodiment. As shown in the figure, this message further includes the previous node address 26 as compared with the case of the message relay system according to the first embodiment. The previous node address 26 records the address of the node device immediately before the message has passed.
It is used as the transit node information in 2 to N5.

FIG. 6 is a diagram showing a configuration of a node device used as nodes N2 to N5 in the message relay system according to the second embodiment of the present invention. As shown in the figure, this node device further includes a transit node information writing unit 28 in addition to the configuration of the node device according to the first embodiment. The transit node information writing unit 28 overwrites and records the address of the node device (own node) over the previous node address 26 included in the received message, and updates it. As a result, the node device that has received this message next can acquire the transit node information by referring to the previous node address 26 included therein. That is, in the node device shown in FIG. 6, the previous node address 26 included in the received
The transit node information acquisition unit 18a can refer to the previous node address 26 and know the node device through which the received message has passed just before.

The message forwarder 20, connection node storage 24, and message reverser 22 are the same as the corresponding components of the node device included in the message relay system according to the first embodiment. Here, the same reference numerals are given and the description is omitted.

FIG. 7 is a flowchart illustrating the operation of the node device according to the second embodiment. 1 includes the same processing steps as those of the flow chart of FIG. 1 already described, and thus those processing steps are denoted by the same reference numerals as those of the flow chart of FIG. 1, and the description here is simple. Stop at

As shown in the figure, in this node device,
If a message is received from another node device (S10
1) The transit node information acquisition unit 18a acquires transit node information by reading the previous node address 26 included therein (S201). Next, the transit node information writing unit 28 rewrites the previous node address 26 included in the received message to the address of the own node (S2).
02).

Thereafter, the message forwarder 20 proceeds to S101.
In step S103, a search is made for a node device to be transferred next from the connected node storage unit 24 using the destination address 12 included in the received message as a search key (S103), and a transfer process is performed for a node device existing in the destination direction (S105). ).
At this time, even if the node device exists in the destination direction,
If it exists at the previous node address 26 acquired in S201, the message is not transferred (S20).
3).

In this way, the processing of S103, S203, and S105 is repeated, and if the message transfer fails for all the other node devices connected in the direction of the destination, or if it is the same as the node device that passed immediately before, Next, the message reversing unit 22 searches the connected node storage unit 24 for a node device to be transferred next using the source address 14 included in the received message as a search key (S1).
06). Then, the message retransmission unit 22 attempts to transfer the message received in S101 to the node device searched in S106, and if the transfer is successful (S10
7), the process in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S108), and the processing in the node device ends.

According to the message relay system described above, for example, when a network failure occurs between the node N3 and the node N5 in the network 10 shown in FIG. 1, the message is transmitted from the node N3 to the node N2. Node N, the node N
In step 2, since it is possible to know that the node that has passed immediately before is the node N3, message transfer in the direction of the transmission destination to the node N3 is restricted (FIG. 7, S203). Then, the message forwarding unit 20 can surely transfer the message to the node N4 that also exists in the destination direction.

As described above, according to the message relay system, despite the fact that a certain node device has forwarded a received message to a node device existing in the direction of the transmission destination, it was not possible to suitably perform the forwarding. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

Further, according to the message relay system according to the second embodiment, since the information of the node which has already passed is included in the message, each node can easily obtain the passing node information regarding the received message. it can.

Embodiment 3 Next, a message relay system according to the third embodiment will be described.

FIG. 8 is a diagram schematically showing a configuration of a message transmitted on the network 10 shown in FIG. 1 in the message relay system according to the third embodiment. As shown in the drawing, this message includes a transit node address list 3 instead of the previous node address 26 as compared with the case of the message relay system according to the second embodiment.
0 is included. This via node address list 3
0 records not only the address of the node device immediately before the message has passed but also a list of addresses of the node devices through which the message has passed. The transit node address list 30 is used as transit node information in the nodes N2 to N5, similarly to the previous node address 26 described above.

The node devices used as nodes N2 to N5 in the message relay system according to the third embodiment have substantially the same configuration as the node devices used in the message relay system according to the second embodiment. And not shown here. Specifically, in the node device according to the present embodiment, the transit node information acquiring unit 18a reads the transit node address list 30 instead of the previous node address 26 from the received message, and the message Message transfer is restricted to the node devices existing in the direction having an address described in the via node address list 30. The transit node information writing unit 28 additionally writes the address of the own node to the transit node address list 30 of the received message. The transit node address list 30 included in the message may be configured as either fixed length data or variable length data.
Further, the number of addresses that can be included therein may be limited within a certain number.

FIG. 9 is a flowchart for explaining the operation of the node device according to the third embodiment. Since the flow chart shown in the figure includes the same processing steps as the flow chart of FIG. 2 already shown, those processing steps are denoted by the same reference numerals as those in the flow chart of FIG. 2, and the description here is simple. Stop at

As shown in the figure, in this node device,
If a message is received from another node device (S10
1) The transit node information acquisition unit 18a acquires transit node information by reading the transit node address list 30 included therein (S301). Next, the transit node information writing unit 28 additionally writes the address of the own node to the transit node address list 30 included in the received message (S302).

Thereafter, the message forwarder 20 proceeds to S101.
In step S103, a search is made for a node device to be transferred next from the connected node storage unit 24 using the destination address 12 included in the received message as a search key (S103), and a transfer process is performed for a node device existing in the destination direction (S105). ).
At this time, even if the node device exists in the destination direction,
It is the via node address list 3 acquired in S201
If it exists at any of the addresses included in 0, no message is transferred to that address (S30).
3).

In this way, the processing of S103, S303, and S105 is repeated, and the message transfer fails for all the other node devices connected in the direction of the destination, or if it is the same as any of the node devices that have passed previously. For example, the message reversing unit 22 searches the connected node storage unit 24 for a node device to be transferred next using the source address 14 included in the received message as a search key (S106). Then, the message back-sending unit 22 determines in S1
Attempt to transfer the message received in S101 to the node device searched in 06, and if the transfer is successful (S107), the processing in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S10).
8), the processing in the node device ends.

According to the message relay system described above, despite the fact that a certain node device has forwarded a received message to a node device existing in the direction of the transmission destination, it has not been possible to suitably perform the transfer. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

According to the message relay system described above, for example, in the network 10 shown in FIG. 1, a network failure occurs between the node N3 and the node N5, and the network failure occurs between the node N4 and the node N5. When a network failure occurs, the node N3
It is possible to prevent the message from being transferred back and forth between the node N4 and the node N4.

That is, according to the message relay system of the second embodiment, for example, a message is transferred from node N3 toward the transmission source due to a network failure between node N3 and node N5, and is temporarily transferred to node N2.
Returns the message to node N
4 is transferred. Thereafter, due to a network failure between the node N4 and the node N5, the node N4 changes to the node N2.
, The message may be transferred from the node N2 to the node N3 again even though a network failure still occurs between the node N3 and the node N5. This is because in the node N2, the transit node information acquisition unit 18a acquires only the address of the node N4, which is the immediately preceding node, and this limits the message transfer to the node N4, but the message transfer to the node N3. Is not limited.

In this regard, according to the message relay system according to the third embodiment, the message to be transferred includes the via-node address list 30, and the addresses of a plurality of nodes that have passed so far are recorded. Therefore, the node N2 can know that the message has already passed through not only the node N4 but also the node N3. Even in the case described above, the node N2 restricts the message transfer to the node N3. Can be.

As described above, according to the message relay system of the third embodiment, each node can use the transit node address list 30 included in the message to obtain a plurality of addresses of the nodes to which the message has already passed. So that when forwarding messages to the destination,
It is possible to further effectively limit the transfer to a node on a route that has already been determined to be unable to transfer a message properly due to a network failure or the like.

Embodiment 4 FIG. Next, a message relay system according to the fourth embodiment will be described.

FIG. 10 is a diagram schematically showing a configuration of a message transmitted on the network 10 shown in FIG. 1 in the message relay system according to the fourth embodiment. As shown in the figure, this message includes an alternative route flag in the transit node address list 30a as compared with the case of the message relay system according to the third embodiment. Specifically, in this message:
An alternative route flag is recorded in association with each node included in the transit node address list 30a. This alternative route flag indicates whether an alternative route has been connected to the correspondingly recorded node. In the present embodiment, the transit node address list 30a included in the message also functions as the alternative route information. I do.

FIG. 11 is a diagram showing a configuration of a node device used as nodes N2 to N5 in the message relay system according to the fourth embodiment. As shown in the figure, this node device further includes a local node alternative route information adding unit 32 in addition to the configuration of the node device according to the second and third embodiments. The own node alternative route information adding unit 32 is a unit that sets an alternative route flag for the own node in association with the address of the own node additionally written in the received message by the transit node information writing unit 28. Specifically, the own node alternative route information adding unit 32 uses the destination address 12 included in the received message as a search key and
Is set, and if a plurality of node devices are connected in the message transmission direction, an alternative route flag relating to the own node is set to “1”, and if a plurality of nodes are not connected, it is set to “0”. Set to

If the message forwarding unit 22a fails to transfer the message in the direction of the destination by the message forwarding unit 20, the source address included in the message is stored in the connection node as a search key. The unit 24 is searched again, and the message is transferred to the node device in the direction of the transmission source obtained thereby. At this time, based on the transit node address list 30a (including the alternative route flag) included in the received message, the node devices to which the alternative route is connected among the node devices existing in the source direction that have already passed are included. Check if there is. Then, if it is determined that the node device to which the alternative route is connected is not among those that have already passed, the transfer of the message to the node device is restricted.

The message forwarding unit 20, connection node storage unit 24, transit node information acquisition unit 18a, and transit node information writing unit 28 correspond to the node devices included in the message relay system according to the third embodiment. Since the configuration is the same as that described above, the same reference numerals are given here and the description is omitted.

FIG. 12 is a flowchart illustrating the operation of the node device according to the fourth embodiment. 9 includes the same processing steps as those in the flow chart of FIG. 9 already described, and therefore those processing steps are denoted by the same reference numerals as those in the flow chart of FIG. Stop at

As shown in the figure, in this node device,
If a message is received from another node device (S10
1) The transit node information acquisition unit 18a acquires transit node information by reading the transit node address list 30a included therein (S401). Next, the transit node information writing unit 28 additionally writes the address of the own node in the transit node address list 30a included in the received message, and the own node alternative information adding unit writes the transit node address list 30a included in the received message.
The alternative route flag relating to the own node is set in a as described above (S402).

Thereafter, the message forwarder 20 proceeds to S10
1 is the destination address 12 included in the received message
Is used as a search key, a node device to be transferred next is searched from the connected node storage unit 24 (S103), and a transfer process is performed on the node device existing in the transmission destination direction (S10).
5). At this time, even if the node device exists in the transmission destination direction, if it exists at any of the addresses included in the transit node address list 30a acquired in S201, the message transfer is performed there. No (S
403).

In this way, the processing of S103, S403, and S105 is repeated, and the message transfer fails for all the other node devices connected in the direction of the destination, or if it is the same as any of the node devices that have passed before. Then, the message reversing unit 22a reads the transit node address list 30a included in the received message to obtain the alternative route information, and determines whether or not an alternative route is connected to a node device existing in the source direction. A determination is made (S404). Then, if it is determined that there is a node to which the alternative route is connected, the transit node address list 3
From 0a, a node device in the source direction to be transferred next is searched (S405). Thereafter, the message is transferred to the node device obtained in S405, and if the message is successful (S406), the processing in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S10).
8), the processing in the node device ends. Also, S4
In the case where the message retransmission unit 22a determines that the node to which the alternative route is connected does not exist in the source direction in 04, similarly, predetermined error processing such as discarding or storing the message is performed (S108). The processing in the node device ends.

According to the message relay system described above, although a certain node device has transferred a received message to a node device existing in the direction of the transmission destination, the transfer cannot be suitably performed. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

According to the message relay system described above, for example, in the network 10 shown in FIG. 1, a network failure occurs between the node N3 and the node N5, and the network failure occurs between the node N4 and the node N5. When a network failure occurs, the message is sent from node N1 → node N2 → node N3 → node N2 →
If the transmission is performed in the order of the node N4 and the node N2, the message transfer from the node N2 to the node N1 can be restricted. That is, since no alternative route is connected to the node N1, the message is transmitted from the node N2 to the node N1.
1 is useless, but according to the message relay system according to the present embodiment, the message to be transmitted also includes the alternative route flag, so that the transfer of such a message to a useless source direction is restricted. can do.

The message relay system according to each of the above embodiments can be variously modified.

For example, the previous node address 26 and the via node address lists 30, 30a included in the message
Does not need to represent the address of each node in the network 10, and may be any information as long as each node can specify the node connected thereto.

In each of the above-described embodiments, the message is discarded or saved as an error process (FIG. 4, S108, etc.). The message may be stored in another node device or the like via the network 10.

In the fourth embodiment, the alternative route information includes the alternative route flag. However, the number of the alternative routes connected to each node and the addresses of the node devices connected to the alternative route are included. The message relay system can be suitably implemented in any case as long as at least information on whether or not the alternative route is connected to the passed node device is included. Each time a message is transferred to an alternative route, the alternative route information included in the message may be updated in any of the node devices.

Further, in the message relay system according to each of the fourth embodiments, it is determined whether or not any of the node devices that perform the message relay process has an alternate route connected in the direction of the transmission source. If there is no node device to which the alternative route is connected, the error processing is performed. However, a node device may be connected to the transmission source in addition to the node device that has already passed. For this reason, in such a case, the message transfer to another node device may be performed while restricting the transfer of the message to the node device that has already passed.

[0068]

According to the present invention described above, when each node forwards a message in the direction of the destination, the forwarding to the node represented by the transit node information is restricted, so that the message is transmitted in the direction of the destination. Even connected nodes can restrict message transfer to nodes that have already passed. As a result, the message can be traced back to the node leading to the alternative route.

Further, according to the present invention, the message is forwarded to the source in a predetermined case. For example, when the message cannot be suitably forwarded to the destination, the message itself is transferred. It is possible to trace back to the node that leads to the alternative route and search for the alternative route. As a result, it is possible to eliminate the need for exchanging messages in advance between nodes, and to effectively transfer messages from an alternative route to a non-fixed network.

Further, according to the present invention, each node includes the information indicating its own node in the message as the transit node information and transfers it to another node, so that the other node can easily receive the information. You can know the transit node information about the message.

Further, according to the present invention, the transit node information is configured as list information representing at least a part of the nodes to which the message has already passed, so that the message is transmitted using the transit node information. By restricting the forwarding of the message to the destination, the message can be more reliably traced back to the node that leads to the alternative route. Further, even when a plurality of nodes cannot appropriately transfer a message in the direction of a transmission destination, it is possible to prevent a message from being transferred back and forth unnecessarily.

Further, according to the present invention, when the message includes the alternative route information and the message is forwarded in each node toward the transmission source, it is determined based on the information that there is no node to which the alternative route is connected. In this case, message transfer to those nodes is restricted. For this reason, if the message is transferred to a node that cannot be transferred by the alternative route, it is possible to limit the unnecessary retracement of the message.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating an example of a network to which a message transfer system according to each embodiment of the present invention is applied.

FIG. 2 is a diagram schematically showing a configuration of a message used in the message transfer system according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a node device used in the message transfer system according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of a node device used in the message transfer system according to the first embodiment of the present invention.

FIG. 5 is a diagram schematically showing a configuration of a message used in a message transfer system according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a node device used in a message transfer system according to a second embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of a node device used in the message transfer system according to the second embodiment of the present invention.

FIG. 8 is a diagram schematically illustrating a configuration of a message used in a message transfer system according to a third embodiment of the present invention.

FIG. 9 is a flowchart illustrating an operation of a node device used in the message transfer system according to the third embodiment of the present invention.

FIG. 10 is a diagram schematically showing a configuration of a message used in a message transfer system according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a configuration of a node device used in a message transfer system according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart illustrating an operation of a node device used in the message transfer system according to the fourth embodiment of the present invention.

[Explanation of symbols]

N1 to N6 nodes, 10 networks, 12 destination addresses, 14 source addresses, 16 message bodies, 18 and 18a via node information acquisition units, 20 message forward transmission units, 22, 22a message reverse transmission units, 2
4 connection node storage unit, 26 own node address, 28
Transit node information writing unit, 30, 30a Transit node address list, 32 own node alternative route information adding unit.

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[Procedure amendment]

[Submission date] April 28, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Message relay system

[Claims]

Wherein said predetermined case, a message switching system according to claim 1, wherein the message sequence sent means is If you can not suitably transfer of messages received for any node .

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates also relates to a message relay cis <br/> Te arm, in particular, to a technology for relaying messages through an alternate path if necessary when message path there are multiple.

[0002]

2. Description of the Related Art Conventionally, in a message relay system in which a message is relayed at a plurality of nodes and links on a network (in this specification, these are simply referred to as "nodes" or "node devices"), a node failure occurs. Therefore, when the message transfer to the next node fails in each node, the message transfer is restarted after recovery from the failure, or the message is discarded or saved and the process ends with an error.

Therefore, according to the conventional technique, even when a plurality of message transfer paths exist from a message transmission source to a transmission destination, if a failure occurs in a certain link, the message transmitted from the transmission source is not transmitted. The link is discarded or saved, and the message relay ends in error. For this reason, there is a problem that the message is not successfully transferred to the destination even though the alternative route, that is, the detour route via the link exists separately.

[0004] In this regard, the detour route search system disclosed in Japanese Patent Application Laid-Open No. Hei 7-264184 discloses a technique for searching for a detour route for a fault location when a node or link in the network has a fault. According to this technique, a node that detects a failure such as a link sends a recovery message to surrounding nodes. Then, when the message reaches the node at the other end of the failure section, this node transfers the message to the node from which the recovery message was originally issued. In this way, the detour path to the fault location is detected by exchanging the recovery message.

[0005]

However, this technique has a problem in that useless data flows on a network because a transfer path is previously secured by exchanging restoration messages.

[0006] The above-mentioned technique may be effective for a fixed network having a plurality of routes.
In a non-fixed network such as the Internet, it is difficult to secure a transfer path in advance, and it is not desirable to apply the above-described conventional technology as it is to a non-fixed network such as the Internet.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to exchange a message effectively on an unfixed network without exchanging messages in advance between nodes. and to provide a message relay system that can be transferred from.

[0008]

According to a first aspect of the present invention, a plurality of nodes connected on a network include message source information, message destination information, and message content information. Receive the message,
The message is transferred to at least one of one or more other nodes existing in the direction of the destination of the message indicated by the message destination information, and the message content information included in the message is transferred to the message indicated by the message source information. A message relay system for transmitting from a transmission source to a message transmission destination indicated in the message transmission destination information, wherein each node obtains transit node information indicating at least one of nodes through which a received message has already passed. Information acquisition means, while restricting transfer of a received message to a node represented by the transit node information acquired by the transit node information acquisition means, in a direction of a message destination indicated in the message destination information; Messages received by any of the existing nodes And message order feeding means for feeding, for a given, a node that exists in the direction of the source of the message in the message transmission source information included in the received message, and message backhaul means for transferring messages received, the Wherein said message comprises:
Alternative route to each of at least some of the nodes via
Route information indicating at least whether or not is connected
And each node includes in the received message
The message indicated in the message destination information
If there are multiple nodes existing in the previous direction,
In the message, information that an alternative route is connected
Own node alternative route information to be added to the alternative route information contained in
Information adding means, wherein the message back-sending means comprises:
Based on the alternative route information,
The node in the direction of the source of the indicated message.
In other words, an alternative route is provided for the node that the message has already passed
If it is determined that the
Restrict forwarding of messages to nodes that have already passed
Things.

[0009] In a second aspect based on the first aspect , the predetermined case is a case where the message forwarding means cannot suitably transfer the received message to any of the nodes.

[0010]

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

FIG. 1 is a diagram showing an overall configuration of a message relay system according to an embodiment of the present invention and a network to which a basic system as a premise thereof is applied. As shown in FIG. 1, the network 10 includes nodes N1 to N1.
N6 is included, where the node N1 is connected to the node N2, and the nodes N3 and N4 are connected. On the other hand, the node N5
6 are connected, and the nodes N3 and N4 are connected. That is, in the network 10, there are two shortest message transfer paths between the node N2 and the node N5, one via the node N3 and one via the node N4.

In the following, a description will be given of a relay of a message in which the transmission source is the node N1 and the transmission destination is the node N6 in the network 10 shown in FIG.

Basic Configuration FIG. 2 shows the message relay system according to the basic configuration 1 in the network 10
FIG. 2 is a diagram schematically showing a configuration of a message for transmitting.
As shown in the figure, the message includes a destination address 12 as message destination information, a source address 14 as message source information, and a message body 16 as message content information. ing. Here, the address of the node N6 is recorded in the transmission destination address 12, and the node N1 is recorded in the transmission source address 14.
Is recorded.

FIG. 3 is a diagram showing a configuration of a node device used as the nodes N2 to N5 of the network 10 in the message relay system according to the first basic configuration . As shown in FIG. 1, the node device includes a transit node information acquisition unit 18, a message forward unit 20, a message reverse unit 22, and a connection node storage unit 24.

Here, the connection node storage unit 24 stores a table indicating to which of the other node devices connected to the node device the message should be transmitted to a certain destination. Is stored, and if an address is given as a search key, the address of the node device connected in the direction of the address is obtained. For example, in the connection node storage unit 24 in the node N2 in FIG. 1, if the addresses of the nodes N5 and N6 are given as search keys, the addresses of the nodes N3 and N4 can be obtained.

The transit node information acquiring unit 18 is means for acquiring transit node information indicating at least one of the nodes to which the received message has already passed. The transit node information acquiring unit 18, for example, as in the message relay system according to an embodiment of implementation you later, acquires information about the node to which the message has traversed already on the basis of the information contained in the received message Or
In addition, when establishing a call between nodes, the above-mentioned transit node information may be obtained separately from transmission and reception of a message.

When a message is received from another node device, the message forwarding unit 20 uses the destination address 12 included in the message as a search key and searches the connected node storage unit 24 for the direction of the destination address 12 (hereinafter, referred to as the destination address) . The address of the node device connected to the “destination direction” is acquired, and the message is transferred to any of the addresses. At this time, the message forwarder 20
Restricts transfer of a message to a node device represented by the transit node information acquired by the transit node information acquisition unit.

The message sending section 22 is connected from the connection node storage section 24 in the direction of the source address 14 (hereinafter referred to as "source direction") using the source address 14 included in the received message as a search key. The address of the node device is acquired, and the message is transferred to any of the addresses. This message reverse transmission unit 22
Is performed when the received message has not been transferred normally due to a network failure or the like, despite the fact that the received message has been transferred to the node device existing in the destination direction by the message forwarding unit 20. The message transfer by the sending unit 20 may be performed when the message transfer cannot be performed suitably, such as when the message cannot be transferred at the expected transfer speed.

FIG. 4 is a flowchart illustrating the operation of the node device having the above configuration. As shown in the figure, when a message is received from another node device (S101), the node device acquires the transit node information by the transit node information acquisition unit 18 as described above (S10).
2). Next, the message forwarding unit 20 searches the connected node storage unit 24 for a node device to be transferred next using the destination address 12 included in the received message in S101 as a search key (S103). Then, when a node device to be transferred next is found, it is determined whether or not the node device is the same as the node device specified by the transit node information acquired in S102 (S104). Returning to S103, another node device is searched again. On the other hand, if it is determined that the node devices are not the same in S104, the received message is transferred to the node device searched in S103. Then, when the transfer is successful (S105), the processing in the node device ends. On the other hand, if the message transfer fails in S105, the process returns to S103 again to search for another node device.

In this way, the processing of S103 to S105 is repeated, and if the message transfer has failed for all the other node devices connected in the direction of the destination or is the same as the node device that has already passed, the next message is sent back. The source address 1 included in the received message by the unit 22
Then, a node device to be transferred next is searched from the connected node storage unit 24 using 4 as a search key (S106). That is,
Here, a node device for transferring the received message toward the transmission source is searched. Then, the message reversing unit 22 sends S1 to the node device searched in S106.
In step S107, the transfer of the message received in step S01 is attempted. If the transfer is successful (S107), the processing in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S108), and the processing in the node device ends.

According to the message relay system described above, for example, when a network failure occurs between the nodes N3 and N5 in the network 10 shown in FIG. 1, the message is transmitted from the node N1 and transferred to the node N3. The message sent from the node N3 to the node N5
It is determined that transfer in the destination direction toward is impossible (S103 to S105), and transfer in the source direction is performed toward the node N2 (S106, S107). next,
In the node N2, if information indicating that the message has already passed through the node N3 has been acquired as the transit node information (S102), the message forwarding unit 20 restricts the transfer of the message to the node N3, and It forwards the received message to another node in the direction, node N4.

Thus, according to the message relay system, although a certain node device has forwarded a received message to a node device existing in the direction of the transmission destination, the forwarding cannot be suitably performed. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

Basic configuration 2. Next, a message relay system according to the basic configuration 2 will be described.

FIG. 5 is a diagram schematically showing a configuration of a message transmitted through the network 10 shown in FIG. 1 in the message relay system according to the basic configuration 2. As shown in the figure, this message further includes the previous node address 26 as compared with the case of the message relay system according to the basic configuration 1 described above. The previous node address 26 is used to record the address of the node device immediately before the message has passed.
5 is used as transit node information.

FIG. 6 is a diagram showing a configuration of a node device used as nodes N2 to N5 in the message relay system according to the basic configuration 2. As shown in the drawing, this node device further includes a transit node information writing unit 28 in addition to the configuration of the node device according to the basic configuration 1. The transit node information writing unit 28 overwrites and records the address of the node device (own node) over the previous node address 26 included in the received message, and updates it. As a result, the node device that has received this message next can acquire the transit node information by referring to the previous node address 26 included therein. That is, in the node device shown in FIG. 6, the previous node address 26 included in the received message is input to the transit node information acquisition unit 18a, and the transit node information acquisition unit 18a transmits the previous node address. 26, it is possible to know the node device through which the received message has passed immediately before.

The message forwarder 20, connection node storage 24, and message reverser 22 are based on
Since the configuration is the same as the corresponding configuration of the node device included in the message relay system according to Configuration 1, the same reference numeral is given here and the description is omitted.

FIG. 7 is a flowchart for explaining the operation of the node device according to the basic configuration 2. 4 includes the same processing steps as those in the flow chart of FIG. 4 already described, and thus those processing steps are denoted by the same reference numerals as those in the flow chart of FIG. 4 , and the description here will be simplified. Stop at

As shown in the figure, in this node device,
If a message is received from another node device (S10
1) The transit node information acquisition unit 18a acquires transit node information by reading the previous node address 26 included therein (S201). Next, the transit node information writing unit 28 rewrites the previous node address 26 included in the received message to the address of the own node (S2).
02).

Thereafter, the message forwarder 20 proceeds to S101.
In step S103, a search is made for a node device to be transferred next from the connected node storage unit 24 using the destination address 12 included in the received message as a search key (S103), and a transfer process is performed for a node device existing in the destination direction (S105). ).
At this time, even if the node device exists in the destination direction,
If it exists at the previous node address 26 acquired in S201, the message is not transferred (S20).
3).

In this way, the processing of S103, S203, and S105 is repeated, and if the message transfer fails for all the other node devices connected in the direction of the transmission destination, or if it is the same as the node device that passed immediately before, Next, the message reversing unit 22 searches the connected node storage unit 24 for a node device to be transferred next using the source address 14 included in the received message as a search key (S1).
06). Then, the message retransmission unit 22 attempts to transfer the message received in S101 to the node device searched in S106, and if the transfer is successful (S10
7), the process in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S108), and the processing in the node device ends.

According to the message relay system described above, for example, when a network failure occurs between the node N3 and the node N5 in the network 10 shown in FIG. 1, a message is transmitted from the node N3 to the node N2. Node N, the node N
In step 2, since it is possible to know that the node that has passed immediately before is the node N3, message transfer in the direction of the transmission destination to the node N3 is restricted (FIG. 7, S203). Then, the message forwarding unit 20 can surely transfer the message to the node N4 that also exists in the destination direction.

As described above, according to the message relay system, although a certain node device has transferred a received message to a node device existing in the direction of the transmission destination, the transfer cannot be suitably performed. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

Further, according to the message relay system of the basic configuration 2, since information on the nodes that have already passed is included in the message, each node can easily obtain the passing node information on the received message.

Basic configuration 3. Next, a message relay system according to the third basic configuration will be described.

FIG. 8 is a diagram schematically showing a configuration of a message transmitted through the network 10 shown in FIG. 1 in the message relay system according to the third basic configuration . As shown in the figure, this message includes a transit node address list 30 instead of the previous node address 26 as compared with the message relay system according to the basic configuration 2 described above. This transit node address list 30 is
In addition to the address of the node device immediately before the message has passed, a list of addresses of the node devices through which the message has passed is recorded. The transit node address list 30 is used as transit node information in the nodes N2 to N5, similarly to the previous node address 26 described above.

The node devices used as the nodes N2 to N5 in the message relay system according to the basic configuration 3 have substantially the same configuration as the node devices used in the message relay system according to the basic configuration 2. It is not shown. Specifically, in the node device according to the basic configuration , the transit node information acquisition unit 1
8a reads the transit node address list 30 from the received message instead of the previous node address 26, and the message forwarder 20 has an address described in the transit node address list 30 among the node devices existing in the destination direction. Restrict message transfer to things. The transit node information writing unit 28 additionally writes the address of the own node to the transit node address list 30 of the received message. The transit node address list 30 included in the message may be configured as either fixed-length data or variable-length data.
The number of addresses that can be included therein may be limited within a certain number.

FIG. 9 is a flowchart illustrating the operation of the node device according to the third basic configuration . 7 includes the same processing steps as those of the flow chart of FIG. 7 already described, and thus those processing steps are denoted by the same reference numerals as those of the flow chart of FIG. 7 , and the description here is simple. Stop at

As shown in the figure, in this node device,
If a message is received from another node device (S10
1) The transit node information acquisition unit 18a acquires transit node information by reading the transit node address list 30 included therein (S301). Next, the transit node information writing unit 28 additionally writes the address of the own node to the transit node address list 30 included in the received message (S302).

Thereafter, the message forwarder 20 proceeds to S101.
In step S103, a search is made for a node device to be transferred next from the connected node storage unit 24 using the destination address 12 included in the received message as a search key (S103), and a transfer process is performed for a node device existing in the destination direction (S105). ).
At this time, even if the node device exists in the destination direction,
It is the via node address list 3 acquired in S301
If it exists at any of the addresses included in 0, no message is transferred to that address (S30).
3).

In this way, the processing of S103, S303, and S105 is repeated, and the message transfer fails for all the other node devices connected in the direction of the destination, or if it is the same as any of the node devices that have passed previously. For example, the message reversing unit 22 searches the connected node storage unit 24 for a node device to be transferred next using the source address 14 included in the received message as a search key (S106). Then, the message back-sending unit 22 determines in S1
Attempt to transfer the message received in S101 to the node device searched in 06, and if the transfer is successful (S107), the processing in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S10).
8), the processing in the node device ends.

According to the message relay system described above, despite the fact that a certain node device has forwarded a received message to a node device existing in the direction of the transmission destination, it has not been possible to suitably perform the transfer. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

According to the message relay system described above, for example, in the network 10 shown in FIG. 1, a network failure occurs between the node N3 and the node N5, and a network failure occurs between the node N4 and the node N5. When a network failure occurs, the node N3
It is possible to prevent the message from being transferred back and forth between the node N4 and the node N4.

That is, according to the message relay system according to the basic configuration 2, for example, a message is transferred from the node N3 toward the transmission source due to a network failure between the node N3 and the node N5, and the message is temporarily transmitted to the node N2. If it returns, then the message is node N4
Is forwarded to Thereafter, if a message returns from the node N4 to the node N2 again due to a network failure between the node N4 and the node N5, even though a network failure still occurs between the node N3 and the node N5, the message is returned again. The message may be transferred from the node N2 to the node N3. This is because, in the node N2, the transit node information acquisition unit 18a acquires only the address of the node N4, which is the immediately preceding node, and this limits the message transfer to the node N4.
This is because message transfer to the node N3 is not restricted.

In this regard, according to the message relay system according to the basic configuration 3, the message to be transferred includes the via-node address list 30, and the addresses of a plurality of nodes that have been passed up to that point are recorded. The node N2 can recognize that not only the node N4 but also the node N3 has already passed the message, and even in the case described above, the node N2 can limit the message transfer to the node N3. .

As described above, according to the message relay system according to the basic configuration 3, each node can use the transit node address list 30 included in the message to obtain a plurality of addresses of the nodes to which the message has already passed. In the message transfer in the direction of the transmission destination, it is possible to further effectively limit the transfer to a node on a route that has already been determined to be unable to perform the message transfer properly due to a network failure or the like.

Embodiment of the present invention. Next, a description will be given message relay system according to the shape condition of the present invention.

[0047] Figure 10 is a diagram schematically showing the structure of a message carrying the network 10 shown in FIG. 1 in a message switching system according to the shape condition of the present embodiment. As shown in the figure, this message includes the basic configuration 3 described above.
The alternative route flag is included in the transit node address list 30a as compared with the case of the message relay system according to (1). Specifically, in this message, an alternative route flag is recorded in association with each node included in the transit node address list 30a. This alternative route flag indicates whether an alternative route has been connected to the correspondingly recorded node. In the present embodiment, the transit node address list 30a included in the message also functions as the alternative route information. I do.

[0048] Figure 11 is a diagram showing the configuration of a node device used as a node N2~N5 In message switching system according to the shape condition of the present embodiment. As shown in the figure, this node device has the same configuration as that of the node devices according to the basic configurations 2 and 3 described above, and also has
2 are also included. The own node alternative route information adding unit 32 is a unit that sets an alternative route flag for the own node in association with the address of the own node additionally written in the received message by the transit node information writing unit 28. Specifically, the own node alternative route information adding unit 32 searches the connection node storage unit 24 using the transmission destination address 12 included in the received message as a search key, and a plurality of node devices are connected in the message transmission direction. If so, the alternative route flag for the own node is set to “1”, and if a plurality of nodes are not connected, it is set to “0”.

When the message forwarding unit 20 cannot transfer the message in the direction of the transmission destination by the message forwarding unit 20 properly, the message sending unit 22a stores the connection source address included in the message as a search key and stores the connection node. The unit 24 is searched again, and the message is transferred to the node device in the direction of the transmission source obtained thereby. At this time, based on the transit node address list 30a (including the alternative route flag) included in the received message, the node devices to which the alternative route is connected among the node devices existing in the source direction that have already passed are included. Check if there is. Then, if it is determined that the node device to which the alternative route is connected is not among those that have already passed, the transfer of the message to the node device is restricted.

The message forwarding unit 20, connection node storage unit 24, transit node information acquisition unit 18a, and transit node information writing unit 28 correspond to the node devices included in the message relay system according to the basic configuration 3. Since the configuration is the same, the same reference numerals are given here and the description is omitted.

[0051] Figure 12 is a flow diagram illustrating the operation of the node device according to the shape condition of the embodiment. 9 includes the same processing steps as those in the flow chart of FIG. 9 already described, and therefore those processing steps are denoted by the same reference numerals as those in the flow chart of FIG. Stop at

As shown in the figure, in this node device,
If a message is received from another node device (S10
1) The transit node information acquisition unit 18a acquires transit node information by reading the transit node address list 30a included therein (S401). Next, the transit node information writing unit 28 additionally writes the address of the own node in the transit node address list 30a included in the received message, and the own node alternative information adding unit 32 writes the transit node address list 30a included in the received message. Then, an alternative route flag for the own node is set as described above (S402).

Thereafter, the message forwarder 20 proceeds to S10
1 is the destination address 12 included in the received message
Is used as a search key, a node device to be transferred next is searched from the connected node storage unit 24 (S103), and a transfer process is performed on the node device existing in the transmission destination direction (S10).
5). In this case, even the node device present in the destination direction, it is as long as it exists in one of the addresses contained in the route node address list 30a acquired in S 401, the transfer of messages there Not performed (S
403).

In this way, the processing of S103, S403, and S105 is repeated, and the message transfer fails for all of the other node devices connected in the direction of the destination, or if it is the same as any of the node devices that have passed before. Then, the message reversing unit 22a reads the transit node address list 30a included in the received message to obtain the alternative route information, and determines whether or not an alternative route is connected to a node device existing in the source direction. A determination is made (S404). Then, if it is determined that there is a node to which the alternative route is connected, the transit node address list 3
From 0a, a node device in the source direction to be transferred next is searched (S405). Thereafter, the message is transferred to the node device obtained in S405, and if the message is successful (S406), the processing in the node device ends. On the other hand, if the transfer of the message fails, predetermined error processing such as discarding or saving the message is performed (S10).
8), the processing in the node device ends. Also, S4
In the case where the message retransmission unit 22a determines that the node to which the alternative route is connected does not exist in the source direction in 04, similarly, predetermined error processing such as discarding or storing the message is performed (S108). The processing in the node device ends.

According to the message relay system described above, although a certain node device has transferred a received message to a node device existing in the direction of a transmission destination, the transfer cannot be suitably performed. In some cases, the message can be transferred in the direction of the transmission source and transferred by an alternative route.

According to the message relay system described above, for example, in the network 10 shown in FIG. 1, a network failure occurs between the node N3 and the node N5, and the network failure occurs between the node N4 and the node N5. When a network failure occurs, the message is sent from node N1 → node N2 → node N3 → node N2 →
If the transmission is performed in the order of the node N4 and the node N2, the message transfer from the node N2 to the node N1 can be restricted. That is, since no alternative route is connected to the node N1, the message is transmitted from the node N2 to the node N1.
1 is useless, but according to the message relay system according to the present embodiment, the message to be transmitted also includes the alternative route flag, so that the transfer of such a message to a useless source direction is restricted. can do.

[0057] Incidentally, the above texture message relay system can be variously modified.

For example, the previous node address 26 and the via node address lists 30, 30a included in the message
Does not need to represent the address of each node in the network 10, and may be any information as long as each node can specify the node connected thereto.

[0059] Also, in the above you facilities has had to perform the discard or save the message as an error process (such as FIG. 4, S108), storage of such messages the node that performs an error process It is not necessary to perform the operation on the device, and the message may be stored in another node device or the like via the network 10.

[0060] Further, Oite the form status of the above embodiment but alternative route information has been configured to include an alternative path flag, the number and the alternate path connected to each node, the node device leading to the alternate route It may be configured to include each address, etc.
In any case, the message relay system can be suitably implemented as long as at least information on whether or not the alternative route is connected to the passed node device is included. Each time a message is transferred to an alternative route, the alternative route information included in the message may be updated in any of the node devices.

[0061] In the message switching system according to the shape condition of the above you facilities, the node device performs relay processing of the message, it determines whether there is a node device alternative route has been connected to the source direction If there is no node device to which the alternative route is connected, the error processing is performed. However, in the transmission source direction, a node device may be connected in addition to the node device that has already passed. For this reason,
In such a case, the message transfer to another node device may be performed while restricting the message transfer to the node device that has already passed.

[0062]

According to the present invention described above, when each node forwards a message in the direction of the destination, the forwarding to the node represented by the transit node information is restricted, so that the message is transmitted in the direction of the destination. Even connected nodes can restrict message transfer to nodes that have already passed. As a result, the message can be traced back to the node leading to the alternative route.

Further, according to the present invention, the message is forwarded to the source in a predetermined case. For example, when the message cannot be suitably forwarded to the destination, the message itself is transmitted. It is possible to trace back to the node that leads to the alternative route and search for the alternative route. As a result, it is possible to eliminate the need for exchanging messages in advance between nodes, and to effectively transfer messages from an alternative route to a non-fixed network.

Further, according to the present invention, when the message includes the alternative route information and each node forwards the message toward the transmission source, it is determined based on the information that there is no node to which the alternative route is connected. In this case, message transfer to those nodes is restricted. For this reason, if the message is transferred to a node that cannot be transferred by the alternative route, it is possible to limit the unnecessary retracement of the message.

[Brief description of the drawings]

1 is an overall configuration diagram showing an example of a network message relayed <br/> system is applied according to the implementation of the embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating a configuration of a message used in a message relay system according to a basic configuration 1 of the present invention.

FIG. 3 is a diagram illustrating a configuration of a node device used in a message relay system according to a basic configuration 1 of the present invention.

FIG. 4 is a flowchart illustrating an operation of a node device used in the message relay system according to the basic configuration 1 of the present invention.

FIG. 5 is a diagram schematically illustrating a configuration of a message used in a message relay system according to a basic configuration 2 of the present invention.

FIG. 6 is a diagram showing a configuration of a node device used in a message relay system according to a basic configuration 2 of the present invention.

FIG. 7 is a flowchart illustrating an operation of the node device used in the message relay system according to the basic configuration 2 of the present invention.

FIG. 8 is a diagram schematically illustrating a configuration of a message used in a message relay system according to a third basic configuration of the present invention.

FIG. 9 is a flowchart illustrating an operation of the node device used in the message relay system according to the basic configuration 3 of the present invention.

10 is a diagram schematically showing the structure of a message used in the message relay <br/> system according to the shape condition of the present invention.

11 is a diagram showing the configuration of a node apparatus used in the message relay <br/> system according to the shape condition of the present invention.

12 is a flowchart describing the operation of the node device used in the message relay <br/> system according to the shape condition of the present invention.

[Description of Signs] N1 to N6 nodes, 10 networks, 12 destination addresses, 14 source addresses, 16 message bodies, node information acquisition sections via 18, 18a, 20 message sequential transmission sections, 22, 22a message reverse transmission sections, 2
4 connection node storage unit, previous node address, 28
Transit node information writing unit, 30, 30a Transit node address list, 32 own node alternative route information adding unit.

Claims (8)

[Claims] A plurality of nodes connected on a network receive a message including message source information, message destination information, and message content information, and determine a destination of a message indicated by the message destination information. Forwards to at least one of the one or more other nodes existing in the direction, and transfers the message content information included in the message from the message source indicated by the message source information to the message indicated by the message destination information A message relay system for transmitting to a destination of the received message, wherein each of the nodes includes: via-node information acquiring means for acquiring via-node information representing at least one of nodes through which a received message has already passed; To the node represented by the transit node information obtained by Message forwarding means for forwarding a received message to any of the nodes existing in the direction of the message destination indicated by the message destination information while restricting the transfer of the received message to the destination. Message forwarding means for forwarding a received message to a node existing in the direction of the message source indicated in the message source information included in the received message. 2. Each of the nodes further includes transit node information writing means for including information representing the own node in a message received as at least a part of transit node information, wherein the transit node information acquisition means includes The message relay system according to claim 1, wherein the transit node information included in the message by the transit node information writing unit is read from the received message. 3. The transit node information included in the message is configured as list information representing at least a part of nodes that the message has already passed, and the transit node information writing unit includes the transit node information writing unit. 3. The message relay system according to claim 2, wherein information indicating the own node is added to the transit node information. 4. The message further includes alternative route information indicating at least whether or not an alternative route is connected to each of at least some nodes through which the message has passed, and each node includes in the received message If there are a plurality of nodes existing in the direction of the message destination indicated in the message destination information to be transmitted, information indicating that an alternative route is connected to the own node is added to the alternative route information included in the message The apparatus further includes a self-node alternative route information adding unit, wherein the message back-sending unit is configured to execute, based on the alternative route information, a message which has already passed through the nodes in the direction of the message source indicated by the message source information. If it is determined that an alternative route has not been connected to the Claim, characterized in that to limit the transfer to de 1
3. The message relay system according to any one of 3. 5. The method according to claim 1, wherein the predetermined case is a case where the message forwarding unit cannot suitably forward the received message to any node. The message relay system as described. 6. A plurality of nodes connected on a network receive a message including message source information, message destination information, and message content information, and determine a destination of a message indicated by the message destination information. Forwards to at least one of the one or more other nodes existing in the direction, and transfers the message content information included in the message from the source of the message indicated by the message source information to the message indicated by the message destination information. A message relay method for transmitting to a transmission destination, wherein the received message obtains via node information indicating at least one of nodes that have already passed, and Received for the node represented by the via node information Message forwarding step of forwarding a received message to any of the nodes existing in the direction of the message destination indicated by the message destination information while restricting the forwarding of the message, A message retransmission step of transferring a received message to a node existing in the direction of the message transmission source indicated by the included message transmission source information. 7. A transit node information acquiring unit for acquiring transit node information representing at least one of the node devices through which a received message has passed, and the message is represented by the transit node information acquired by the transit node information acquisition unit. Message forwarding means for forwarding a received message to any of the nodes present in the direction of the message destination indicated in the message destination information while restricting the transfer of the received message to a given node; A node device comprising: a message sending unit that transfers a received message to a node device existing in the direction of the message source indicated by the message source information included in the received message. 8. A plurality of node devices connected on a network receive a message including message source information, message destination information, and message content information,
The message is transferred to at least one of one or more other node devices existing in the direction of the destination of the message indicated by the message destination information, and the message content information included in the message is indicated by the message source information. An information recording medium storing a program for operating a computer as a node device used in a message relay system for transmitting a message from a transmission source to a message transmission destination indicated in the message transmission destination information, wherein the node on which the received message has already passed is stored. Via node information acquiring step of acquiring via node information representing at least one of the devices, and while limiting transfer of a received message to a node represented by the via node information acquired in the via node information acquiring step, The message destination Forwarding a received message to any node existing in the direction of the destination of the message indicated by the message, and, in a predetermined case, transmitting the message indicated by the message source information included in the received message An information recording medium storing a program for causing a computer to execute a message reverse transmission step of transferring a received message to a node device existing in an original direction.