JP2003234747A - Duplex ring network system and ring selecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch a ring for transmission or reception at high speed for the purpose of avoiding the fault of a transmission line or the like in a plurality of nodes comprising a duplex ring network. <P>SOLUTION: In a plurality of nodes 2-1 to 2-n, a health check packet recorded with a remaining time is periodically transmitted to both rings and repeated along with the rings after subtracting the remaining time of a health check packet arriving from the other node. In the process discarding the health check packet arriving from the present node, on the other hand, the arrival/non-arrival of the health check packet from the other node is monitored for each transmission source node and when the packets arrive from both rings, the ring with the arriving health check packet having a longer remaining time is selected as a receiving ring. When the packet arrives from only one ring, the relevant one ring is selected as the receiving ring. Thus, the relationship of the receiving ring to the transmission source node is found and held to be updated and according to these held contents, data packets are transmitted and received. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. The present invention relates to a ring selection method in which a plurality of nodes detect a failure such as a transmission path and switch a ring for transmission or reception in order to avoid the failure.

[0002]

2. Description of the Related Art Conventionally, for example, a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions has been known. Kaihei 8-181710
The one disclosed in Japanese Laid-Open Patent Publication (ring type ATM network system) is known. The outline will be described below with reference to FIGS. 34 and 35. Note that FIG. 34 is a configuration example of a conventional dual ring network system. FIG. 35 shows
It is a block diagram which shows the internal structure of the conventional node shown in FIG.

In FIG. 34, the dual ring network system includes a dual ring 153 composed of a primary ring 151 and a secondary ring 152 having opposite directions, and the dual ring 153 as a transmission medium or line. Are connected to a plurality of nodes 154-1 to 154-n. In this conventional dual ring network system, data packets are transmitted and received between arbitrary nodes via the primary ring 151 or the secondary ring 152.

As shown in FIG. 35, the node 200 includes a ring interface section (ring I / F section) 201, 20.
2, a switch unit 203, and a data packet processing unit 204. The ring I / F units 201 and 202 terminate the ring lines (the primary ring 151 and the secondary ring 152) connected to the ring ports 205 and 206. The data packet processing unit 204 processes the data packet passed from the switch unit 203, and also processes the data packet passed to the switch unit 203.

The switch unit 203 refers to the destination node ID described in the data packet, and the following (1) to
Packet exchange is performed as in (3). (1) Ring I /
When the data packet arriving from the F units 201 and 202 is addressed to its own node, it is passed to the data packet processing unit 204.
(2) When a data packet arriving from one of the ring I / F units 201 and 202 is addressed to another node, it is passed to the other of the ring I / F units 201 and 202. That is, relay it.
(3) The data packet arriving from the data packet processing unit 204 is passed to the ring I / F units 201 and 202 and sent to the dual ring 153.

[0006] Conventionally, each node has a database in which the node connection order on the ring and the position of its own node are described. Then, based on the database, each node preliminarily constructs, for each combination of nodes, a transmission ring selection table in which a ring with a small number of transit nodes (hereinafter, referred to as “hop number”) is described.

Next, the operation will be described. When both rings are normal, each source node sends a data packet to one ring based on the transmission ring selection table. Then, the node that has detected the failure of the transmission path or the adjacent node notifies the network management packet to all the other nodes. Each transmission source node that has received this network management packet rewrites the transmission ring selection table so as to avoid a failure, and based on this, sends the data packet to one ring.

[0008]

However, the conventional ring selection method in the dual ring network system has the following problems (1) to (3), so that it is difficult to increase the speed by hardware processing. .

(1) Since it is necessary to preset in each node a database in which the node connection order on the ring and the position of the own node are set in advance, each time the node is relocated, added or deleted, etc. You have to manually update the database.

(2) When selecting and transmitting a ring with a small number of hops, each node needs to previously generate a transmission ring selection table in which a ring with a small number of hops is described for each combination of nodes. Therefore, updating the transmission ring selection table is complicated when the nodes are relocated, added or deleted.

(3) Each node recognizing a failure of the transmission line or the node due to the arrival of the network management packet needs to refer to the above-mentioned database, extract the affected path, and reflect it in the ring selection table. Processing is complicated.

As described above, in the conventional ring selection method, updating of the database and the transmission ring selection table is complicated, and the software processing is appropriate, so that it is difficult to speed up by the hardware processing.

The present invention has been made in view of the above,
An object of the present invention is to obtain a dual ring network system and a ring selection method which are provided with a mechanism for rapidly switching the ring that each node transmits or receives when a failure occurs in a transmission line or the like.

[0014]

In order to achieve the above object, a dual ring network system according to the present invention is a transmission medium comprising a dual ring of a primary ring and a secondary ring having opposite directions. Alternatively, in a double ring network system in which a plurality of nodes are connected via a line, the plurality of nodes periodically transmits a health check packet indicating the remaining time to both rings, and a health check originating from another node arrives. While subtracting the remaining time of the packet and relaying along the ring, the health check packet transmitting / receiving means for discarding the health check packet originating from the own node, and the process of transmitting / receiving the health check packet, for each source node The arrival / non-arrival of health check packets originating from other nodes is monitored, and when they arrive from both rings, When the health check packet with a longer lifetime arrives, the ring is selected as the receiving ring for the data packet originating from the other node, and if it arrives from only one ring, that one ring receives the data packet originating from the other node. By choosing as a ring,
Receiving ring selecting means for determining the relationship of the receiving ring with respect to the source node and holding it updatable, transmitting data packets to both rings, relaying data packets addressed to other nodes along the rings, and arriving at its own node Data packet transmitting / receiving means for receiving or discarding the addressed data packet based on the contents held in the receiving ring selecting means.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet indicating the remaining time to both rings,
The arrived health check packet originating from another node is relayed along the ring after subtracting the remaining time, while the health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the receiving ring selection means monitors the arrival / non-arrival of the health check packet originating from another node for each source node, and when it arrives from both rings, it remains. The ring in which the health check packet with a longer time arrives is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring is the receiving ring for the data packet originating from the other node. By selecting as, the relationship of the receiving ring with respect to the source node is obtained and held so that it can be updated. In this state, the data packet transmitting / receiving means transmits the data packet to both rings, and the arriving data packet addressed to another node is relayed along the ring, while the arriving data packet addressed to the own node is transmitted to the receiving ring selecting means. It is received or abandoned based on the content held in.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmits a health check packet to both rings, relays the arrived health check packet from another node along the ring, and receives the arrived health check packet from its own node. In the process of transmitting / receiving the health check packet with the discarding health check packet transmitting / receiving means, arrival / non-arrival of the health check packet originating from another node is monitored for each source node, and when the health check packet arrives from both rings, The ring in which the check packet arrived first received the data packet originating from the other node. When it is selected as a ring and arrives from only one ring, the one ring is selected as a receiving ring of the data packet originating from the other node, and the relationship of the receiving ring with respect to the transmission source node is obtained and held as updatable. Receiving ring selecting means for transmitting data packets to both rings and relaying the arriving data packet addressed to another node along the ring, while arriving the data packet addressed to its own node based on the content held by the receiving ring selecting means. And a data packet transmitting / receiving unit for receiving or discarding.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the receiving ring selecting means,
The arrival / non-arrival of health check packets originating from other nodes is monitored for each source node, and when they arrive from both rings,
The ring in which the health check packet arrives first is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring is selected as the receiving ring for the data packet originating from the other node. By doing so, the relationship of the receiving ring with respect to the transmission source node is obtained and held so that it can be updated. In this state,
The data packet transmitting / receiving means transmits the data packet to both rings, and the arriving data packet addressed to another node is relayed along the ring, while the arriving data packet addressed to the own node is stored in the receiving ring selection means. It is received or discarded based on the above.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line consisting of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmit a health check packet indicating the remaining time to both rings, subtract the remaining time of the arrived health check packet from another node, and relay the health check packet along the ring. On the other hand, the arrival / non-arrival of the health check packet is monitored for each source node in the process of transmitting / receiving the health check packet with the health check packet transmitting / receiving means for discarding the health check packet originating from the own node. If the outgoing health check packet arrives from both rings,
The ring where the health check packet with less remaining time arrives for each sending node is selected as the sending ring of the data packet whose other node is the destination node, and when it arrives from only one ring, the other ring is selected. If it is selected as the transmission ring common to all destination nodes and if it does not arrive from both rings, both rings are selected as the transmission ring common to all destination nodes, and the relationship of the transmission ring to the destination node can be obtained and updated. A transmission ring selecting means to hold and a data packet are transmitted to both rings based on the contents held by the transmission ring selecting means, and a arriving data packet addressed to another node is relayed along the ring, while a arriving data packet addressed to its own node. And a data packet transmitting / receiving unit for receiving the packet.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet indicating the remaining time to both rings,
The arrived health check packet originating from another node is relayed along the ring after subtracting the remaining time, while the health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the table generation means monitors the arrival / non-arrival of the health check packet for each source node, and when the health check packet originating from the own node arrives from both rings. Selects a ring on which a health check packet with a shorter remaining time arrives for each transmission node as the transmission ring whose other node is the destination node, and when it arrives from only one ring, the one ring is If another node selects the transmission ring as the destination node and does not arrive from both rings, select both rings as the transmission ring common to all destination nodes, and the relationship of the transmission ring to the destination node is obtained and updated. Retained as possible. In this state, the data packet transmitting / receiving means
The data packet is transmitted to both rings based on the content held by the transmission ring selection means, and the arrived data packet addressed to another node is relayed along the ring, while the arrived data packet addressed to its own node is received.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmits a health check packet to both rings, relays the arrived health check packet from another node along the ring, and receives the arrived health check packet from its own node. The arrival / non-arrival of the health check packet is monitored for each source node in the process of transmitting and receiving the health check packet to be discarded and the health check packet.
When the health check packet originated from the own node arrives from both rings, the ring where the health check packet arrives later for each transmitting node is selected as the transmitting ring of the data packet whose destination node is the other node, and only one ring is selected. If it arrives from, select the one ring as a transmission ring common to all destination nodes, and if it does not arrive from both rings, by selecting both rings as a transmission ring common to all destination nodes, A transmission ring selection unit that obtains the relationship of the transmission ring with respect to the destination node and holds it so that it can be updated, and a data packet is transmitted to both rings based on the contents held by the transmission ring selection unit. Data packet transmission / reception that receives data packets addressed to its own node while relaying Characterized by comprising a means.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the transmission ring selection means
The arrival / non-arrival of the health check packet is monitored for each source node. If it is selected as a transmission ring for data packets addressed to another node and arrives from only one ring, that one ring is selected as a transmission ring common to all destination nodes. By selecting the ring as the transmission ring common to all destination nodes, the relationship of the transmission ring to the destination node is determined and maintained updatable. In this state, the data packet transmitting / receiving means transmits the data packet to both rings based on the content held by the transmission ring selecting means, and the arriving data packet addressed to the other node is relayed along the ring, while the arriving self packet arrives. The data packet addressed to the node is received.

In the dual ring network system according to the next invention, in the above invention, the data packet transmitting / receiving means arrives from both rings and a number adding means for adding a serial number to a data packet to be transmitted to both rings. When the data packet originates from the same node and has the same number and is a data packet addressed to its own node, it is provided with a selective receiving means for receiving only the data packet arriving from one ring.

According to this invention, in the above invention,
In the data packet transmitting / receiving means, the serial number is added to the data packets to be transmitted to both rings by the number adding means. Then, in the selective receiving means, the data packets arriving from both rings originate from the same node and have the same number,
When it is the data packet addressed to the own node, only the data packet arriving from one ring is received.

In the dual ring network system according to the next invention, in the above invention, the arrival status of the health check packet is monitored for each source node in the process of transmitting and receiving the health check packet, When there is a change in the arrival status, a reception prohibition period setting means for setting a data packet reception prohibition period for a certain period, and an operation that the data packet transmission / reception means operate to receive from both rings within the data packet reception prohibition period. The data packet addressed to the node is provided with a discarding means for discarding.

According to this invention, in the above invention,
In the process of transmitting and receiving the health check packet, the reception prohibition period setting means monitors the arrival status of the health check packet for each source node, and when the arrival status of the health check packet changes, data for a certain period A packet reception prohibited period is set. Then, in the operation process of the data packet transmitting / receiving means, the discarding means discards the data packet addressed to the own node which has arrived from both rings within the data packet reception prohibited period.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring selection method in the dual ring network system described above, the plurality of nodes periodically transmit a health check packet indicating the remaining time to both rings, and the remaining time of the health check packet originating from another node arrives. While sending and receiving along with the ring, the health check packet transmission / reception process of discarding the health check packet originating from its own node and the process of transmitting / receiving the health check packet. The arrival / non-arrival of check packets is monitored, and if they arrive from both rings, The ring on which the health check packet with more remaining time arrives is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring receives the data packet originating from the other node. By selecting the ring, the receiving ring selection step of obtaining the relationship of the receiving ring with respect to the source node and holding it updatable, and transmitting the data packet to both rings, and relaying the arriving data packet addressed to another node along the ring On the other hand, the data packet transmission / reception step of receiving or discarding the arrived data packet addressed to the own node based on the content held in the reception ring selection step is included.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet indicating the remaining time is periodically transmitted to both rings,
The arrived health check packet originating from another node is relayed along the ring after subtracting the remaining time, while the health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, arrival / non-arrival of the health check packet originating from another node is monitored for each source node in the receiving ring selection step, and when the packet arrives from both rings, it remains. The ring in which the health check packet with a longer time arrives is selected as the receiving ring of the data packet originating from the other node, and when it arrives from only one ring, the one ring is the receiving ring of the data packet originating from the other node. By selecting as, the relationship of the receiving ring with respect to the source node is obtained and held so that it can be updated. In this state, in the data packet transmission / reception step, the data packet is transmitted to both rings, and the arrived data packet addressed to the other node is relayed along the ring, while the arrived data packet addressed to the own node is transmitted to the reception ring selection table. It is received or discarded based on the setting.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. A method of selecting a ring in a dual ring network system, wherein the plurality of nodes periodically transmits a health check packet to both rings, and relays a health check packet originating from another node along the ring. On the other hand, in the health check packet transmitting / receiving step of discarding the health check packet originating from the own node and in the process of transmitting / receiving the health check packet, arrival / non-arrival of the health check packet originating from another node is monitored for each source node. , If it arrives from both rings, the health check packet arrives first. The selected ring is selected as the receiving ring for the data packet originating from the other node, and when the ring arrives from only one ring, the source node is selected by selecting the one ring as the receiving ring for the data packet originating from the other node. Receiving ring selection step of obtaining the relationship of the receiving ring with respect to and holding it in an updatable manner, transmitting the data packet to both rings, relaying the arriving data packet addressed to another node along the ring, and arriving the own node addressed data packet And a data packet transmitting / receiving step of receiving or discarding the packet based on the contents held in the receiving ring selecting step.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of receiving and selecting such a health check packet, in the receiving ring selection step,
The arrival / non-arrival of health check packets originating from other nodes is monitored for each source node, and when they arrive from both rings,
The ring in which the health check packet arrives first is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring is selected as the receiving ring for the data packet originating from the other node. By doing so, the relationship of the receiving ring with respect to the transmission source node is obtained and held so that it can be updated. In this state,
In the data packet transmitting / receiving step, the data packet is transmitted to both rings, and the arrived data packet addressed to the other node is relayed along the ring, while the arrived data packet addressed to the own node is based on the setting of the reception ring selection table. It is received or discarded.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a primary ring and a secondary ring having opposite directions. A method of selecting a ring in a dual ring network system according to claim 1, wherein the plurality of nodes periodically send a health check packet indicating the remaining time to both rings, and the ring of the health check packet originating from another node arrives. The health check packet transmission / reception process of discarding the health check packet originating from its own node while relaying along the health check packet and the process of transmitting / receiving the health check packet.
When non-arrival is monitored and the health check packet originating from the own node arrives from both rings, the ring where the health check packet with a shorter remaining time arrives for each sending node is transferred to the data packet whose other node is the destination node. If it is selected as the transmission ring and arrives from only one ring, it is selected as the common transmission ring for all destination nodes, and if it does not arrive from both rings, both rings are designated as the destination nodes. By selecting as a common transmission ring, the transmission ring selection step of obtaining the relationship of the transmission ring with respect to the destination node and holding it updatable,
A data packet transmission / reception step of transmitting a data packet to both rings based on the contents held in the transmission ring selection step and relaying it along the ring of the data packet addressed to another node while receiving the data packet addressed to its own node It is characterized by including and.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet indicating the remaining time is periodically transmitted to both rings,
The arrived health check packet originated from another node is relayed along the ring, while the arrived health check packet originated from the own node is discarded. When such a health check packet is transmitted and received, the arrival / non-arrival of the health check packet is monitored for each source node in the transmission ring selection step, and the health check packet originating from the own node arrives from both rings. , The ring on which the health check packet with less remaining time arrives for each sending node is selected as the sending ring for the data packet destined for the other node destined for the own node. If the ring is selected as the common transmission ring for all destination nodes and if it does not arrive from both rings, both rings are selected as the common transmission ring for all destination nodes so that the relationship of the transmission ring to the destination node is the transmission ring. It is set in the selection table. In this state, in the data packet transmission / reception step, the data packet is transmitted to both rings based on the contents held in the transmission ring selection step, and the arrived data packet addressed to another node is relayed along the ring and arrived. The data packet addressed to the own node is received.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. A method of selecting a ring in a dual ring network system, wherein the plurality of nodes periodically transmits a health check packet to both rings, and relays a arrived health check packet originating from another node along the ring. On the other hand, in the health check packet transmitting / receiving step of discarding the health check packet originating from the own node and in the process of transmitting / receiving the health check packet, arrival / non-arrival of the health check packet is monitored for each source node, If the outgoing health check packet arrives from both rings, For each packet, the ring where the health check packet arrives later is selected as the transmission ring of the data packet whose other node is the destination node, and if it arrives from only one ring, that one ring is common to all the destination nodes. If the health check packets originating from the local node do not arrive from both rings, select both rings as common transmission rings to all destination nodes, and obtain the relationship between the transmission rings for the destination nodes and update. A transmission ring selection step that holds the data packet as possible, and a data packet is transmitted to both rings based on the content held in the transmission ring selection step and relayed along the ring of the data packet addressed to another node that has arrived And a data packet transmitting / receiving step of receiving the addressed data packet.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, in the transmission ring selection step,
The arrival / non-arrival of the health check packet is monitored for each source node. If it is selected as a transmission ring for data packets addressed to another node and arrives from only one ring, that one ring is selected as a transmission ring common to all destination nodes. By selecting the ring as the transmission ring common to all destination nodes, the relationship of the transmission ring to the destination node is determined and maintained updatable. In this state, in the data packet transmission / reception step, the data packet is transmitted to both rings based on the contents held in the transmission ring selection step, and the arrived data packet addressed to another node is relayed along the ring and arrived. The data packet addressed to the own node is received.

In the ring selection method in the dual ring network system according to the next invention, in the above invention, the data packet transmitting / receiving step includes a number adding step of adding a serial number to data packets to be transmitted to both rings, and When the data packet arriving from the ring is the data packet originating from the same node and having the same number and addressed to the own node, a selective receiving step of receiving only the data packet arriving from one ring is included. .

According to this invention, in the above invention,
In the data packet transmission / reception process, a serial number is added to the data packets to be transmitted to both rings in the number addition process. Then, in the selective reception step, the data packets arriving from both rings originate from the same node and have the same number,
When it is the data packet addressed to the own node, only the data packet arriving from one ring is received.

In the ring selection method in the dual ring network system according to the next invention, in the above invention, the arrival status of the health check packet is monitored for each source node in the process of transmitting and receiving the health check packet, When there is a change in the arrival status of the health check packet, in the reception prohibited period setting step of setting a data packet reception prohibited period for a certain period and in the data packet transmission / reception step, the data arrives from both rings within the data packet reception prohibited period. The data packet addressed to its own node is characterized by including a discarding step of discarding.

According to this invention, in the above invention,
In the process of transmitting / receiving the health check packet, the arrival status of the health check packet is monitored for each source node in the reception prohibition period setting step, and when the arrival status of the health check packet changes, data for a certain period A packet reception prohibited period is set. Then, in the operation process of the data packet transmission / reception process, in the discarding process, the data packet addressed to the own node which has arrived from both rings within the data packet reception prohibited period is discarded.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmits a health check packet to both rings, relays the arrived health check packet from another node along the ring, and receives the arrived health check packet from its own node. In the process of transmitting / receiving the health check packet to / from the discarding health check packet transmitting / receiving means, arrival / non-arrival of the health check packet originating from the own node is monitored for each source node, and if arrival from both rings, transmission is performed. Bit at the specified bit position of the destination node identifier of the unicast data packet Select the ring defined by the logical value as the transmission ring, select one ring as the transmission ring if it arrives from only one ring, or both rings if it does not arrive from both rings. And a unicast data packet transmitted to the ring based on the selection result, the unicast data packet arriving at another node is relayed along the ring, and the unicast data packet arriving at the own node is transmitted. And a data packet transmitting / receiving means for receiving and processing the cast data packet.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the transmission ring selection means
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the unicast data packet to be transmitted is selected as the transmission ring and arrives from only one ring. If so, one of the rings is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, the data packet transmitting / receiving means transmits the unicast data packet to the ring based on the selection result. Then, the arrived unicast data packet addressed to another node is relayed along the ring. Also,
The unicast data packet addressed to its own node is received and processed.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmits a health check packet to both rings, relays the arrived health check packet from another node along the ring, and receives the arrived health check packet from its own node. In the process of transmitting / receiving the health check packet to / from the discarding health check packet transmitting / receiving means, arrival / non-arrival of the health check packet originating from the own node is monitored for each source node, and if arrival from both rings, transmission is performed. To identify a group of multiple destination nodes for a multicast data packet Select the ring defined in accordance with the logical values of bits of a predetermined bit position of the node group identifier as the transmission ring, when arriving from only one ring, select the one of the ring as the transmission ring,
When not arriving from both rings, transmission ring selection means for selecting both rings as transmission rings, and transmitting the multicast data packet to the ring based on the selection result, and arriving the multicast data packet originating from another node along the ring. And a data packet transmitting / receiving unit that performs a reception process and discards the arrived multicast data packet originating from the own node.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the transmission ring selection means
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node group identifier that identifies the group of the plurality of destination nodes of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, the data packet transmitting / receiving means transmits the multicast data packet to the ring based on the selection result. Then, the arrived multi-node originated multicast data packet is relayed along the ring and received. In addition, the arrived multicast data packet originating from the own node is discarded.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmits a health check packet to both rings, relays the arrived health check packet from another node along the ring, and receives the arrived health check packet from its own node. The arrival / non-arrival of the health check packet is monitored for each source node in the process of sending and receiving the health check packet with the discarding health check packet transmitting / receiving means.
When the health check packet originated from the own node arrives from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted is selected as the transmission ring, and If it arrives from only one ring, it selects one of the rings as the transmission ring, and if it does not arrive from both rings, it selects both rings as the transmission ring and the transmission ring selection means and the transmission from the accommodating terminal. The received unicast data packet is transmitted to the ring based on the selection result, the unicast data packet arriving from another node is relayed along the ring, and the unicast is sent to the terminal accommodated by the own node. Unicast data originating from the local node that arrived after relaying the data packet to the corresponding terminal Characterized in that a data packet transmission and reception means for disposing of packets.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the transmission ring selection means
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. When arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted is selected as the transmission ring and arrives from only one ring. If so, one of the rings is selected as the transmitting ring, and if no ring arrives from both rings, both rings are selected as the transmitting rings. As a result, the data packet transmitting / receiving means transmits the unicast data packet sent from the accommodated terminal to the ring based on the selection result. Then, the unicast data packet arriving from another node is relayed along the ring, and when the unicast data packet is addressed to the terminal accommodated by the own node, the unicast data packet is relayed to the accommodated terminal. Further, the unicast data packet originating from the own node that has arrived is discarded.

A dual ring network system according to the next invention is a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the ring network system, the plurality of nodes periodically transmits a health check packet to both rings, relays the arrived health check packet from another node along the ring, and receives the arrived health check packet from its own node. The arrival / non-arrival of the health check packet is monitored for each source node in the process of transmitting and receiving the health check packet transmitting / receiving means to be discarded
When the health check packet originating from the own node arrives from both rings, it is determined according to the logical value of the bit at the predetermined bit position of the destination terminal group identifier that identifies the group of multiple destination terminals of the multicast data packet to be transmitted. Select a ring as the transmit ring, select one ring as the transmit ring if it arrives from only one ring, or select both rings as the transmit ring if it does not arrive from both rings The selecting means and the multicast data packet sent from the accommodating terminal are transmitted to the ring based on the selection result, and the arrived multicast data packet originating from another node is relayed along the ring and addressed to the terminal accommodated by the own node. If the multicast data packet is Relaying the end, characterized in that the self-node onset multicast data packets arriving with a data packet transmission and reception means for disposal.

According to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the transmission ring selection means
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. When arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal group identifier that identifies the group of the plurality of destination terminals of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, the data packet transmitting / receiving means transmits the multicast data packet transmitted from the terminal to be accommodated to the ring based on the selection result. Then, the arrived multicast data packet originating from another node is relayed along the ring, and when it is addressed to the terminal accommodated by the own node, the multicast data packet is relayed to the accommodated terminal. In addition, the arrived multicast data packet originating from the own node is discarded.

In the dual ring network system according to the next invention, in the above invention, the transmission ring selection means has a part or all of the identifier when a health check packet originated from its own node arrives from both rings. On the other hand, it is characterized in that a means for carrying out a predetermined calculation to obtain a random bit value is provided, and a ring defined according to the bit value is selected as a transmission ring.

According to this invention, in the above invention,
In the transmission ring selection means, when the health check packet originated from the own node arrives from both rings, a random calculation is performed on a part or all of the identifier to obtain a random bit value, and the bit value is The ring determined accordingly is selected as the transmission ring.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. A method of selecting a ring in a dual ring network system, wherein the plurality of nodes periodically transmits a health check packet to both rings, and relays a health check packet originating from another node along the ring. On the other hand, in the health check packet transmitting / receiving step of discarding the health check packet originating from the own node and the process of transmitting / receiving the health check packet, arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. , Unicast data packet to be sent when arriving from both rings Select a ring defined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the destination ring as the transmission ring, and when arriving from only one ring, select the one ring as the transmission ring, If it does not arrive from both rings, the transmission ring selection step of selecting both rings as transmission rings, and the unicast data packet is transmitted to the ring based on the selection result, and the arrived unicast data packet addressed to another node is ringed. And a data packet transmitting / receiving step of receiving and processing the unicast data packet addressed to the own node which is relayed along the line.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, in the transmission ring selection step,
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the unicast data packet to be transmitted is selected as the transmission ring and arrives from only one ring. If so, one of the rings is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, in the data packet transmitting / receiving step, the unicast data packet is transmitted to the ring based on the selection result. Then, the arrived unicast data packet addressed to another node is relayed along the ring. Also,
The unicast data packet addressed to its own node is received and processed.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the dual ring network system described above, the plurality of nodes periodically transmits health check packets to both rings and relays the health check packets originating from other nodes along the rings while arriving at its own node. During the health check packet transmission / reception process of discarding the originating health check packet and the process of transmitting / receiving the health check packet, arrival / non-arrival of the own node originating health check packet is monitored for each source node and arrives from both rings. If you send multiple multicast data packets to multiple destination The ring determined according to the logical value of the bit at the predetermined bit position of the destination node group identifier that identifies the group is selected as the transmission ring, and if only one ring arrives, the one ring is transmitted. , And if it does not arrive from both rings, the transmission ring selection step of selecting both rings as transmission rings, and the multicast data packet that has arrived by transmitting the multicast data packet to the ring based on the selection result and has arrived And a data packet transmitting / receiving step of performing a reception process and discarding the arrived multicast data packet originated from its own node.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, in the transmission ring selection step,
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node group identifier that identifies the group of the plurality of destination nodes of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, in the data packet transmitting / receiving step, the multicast data packet is transmitted to the ring based on the selection result. Then, the arrived multi-node originated multicast data packet is relayed along the ring and received. In addition, the arrived multicast data packet originating from the own node is discarded.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the dual ring network system described above, the plurality of nodes periodically transmits a health check packet to both rings and relays a health check packet originating from another node along the ring while arriving at its own node. In the process of transmitting / receiving the health check packet for discarding the source health check packet and in the process of transmitting / receiving the health check packet, arrival / non-arrival of the health check packet is monitored for each source node and If it arrives from the ring, it will send the unicast data The ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal identifier of the packet is selected as the transmission ring, and if the ring arrives from only one ring, the one ring is selected as the transmission ring. ,
If it does not arrive from both rings, the transmission ring selection step of selecting both rings as the transmission ring, and the unicast data packet sent from the accommodating terminal is transmitted to the ring based on the selection result and arrived. It relays the unicast data packet originating from the node along the ring, and when it is addressed to the terminal accommodated by its own node, relays the unicast data packet to the accommodating terminal and discards the unicast data packet originating from the own node. And a data packet transmitting / receiving step for processing.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, in the transmission ring selection step,
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. When arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted is selected as the transmission ring and arrives from only one ring. If so, one of the rings is selected as the transmitting ring, and if no ring arrives from both rings, both rings are selected as the transmitting rings. As a result, in the data packet transmitting / receiving step, the unicast data packet transmitted from the accommodating terminal is transmitted to the ring based on the selection result. Then, the unicast data packet arriving from another node is relayed along the ring, and when the unicast data packet is addressed to the terminal accommodated by the own node, the unicast data packet is relayed to the accommodated terminal. Further, the unicast data packet originating from the own node that has arrived is discarded.

In the ring selection method in the dual ring network system according to the next invention, a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. In the dual ring network system described above, the plurality of nodes periodically transmits health check packets to both rings and relays the health check packets originating from other nodes along the rings while arriving at its own node. In the process of transmitting / receiving the health check packet for discarding the source health check packet and in the process of transmitting / receiving the health check packet, arrival / non-arrival of the health check packet is monitored for each source node and Multicast data to send when arriving from the ring A ring selected according to the logical value of the bit at the predetermined bit position of the destination terminal group identifier that identifies a group of a plurality of destination terminals of a packet is selected as the transmission ring, and if it arrives from only one ring, If one ring is selected as the transmission ring and it does not arrive from both rings, the transmission ring selection step of selecting both rings as the transmission ring and the multicast data packet sent from the accommodating terminal as the selection result. Based on this, the multicast data packet originating from another node is relayed along the ring, and when it is addressed to the terminal accommodated by the own node, the multicast data packet is relayed to the accommodated terminal and the arrived own node Data packet transmission / reception that discards outgoing multicast data packets Characterized in that it comprises a step.

According to the present invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, in the transmission ring selection step,
Arrival / non-arrival of the health check packet originating from the own node is monitored for each source node. When arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal group identifier that identifies the group of the plurality of destination terminals of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, in the data packet transmission / reception step, the multicast data packet transmitted from the accommodating terminal is transmitted to the ring based on the selection result. Then, the arrived multicast data packet originating from another node is relayed along the ring, and when it is addressed to the terminal accommodated by the own node, the multicast data packet is relayed to the accommodated terminal. In addition, the arrived multicast data packet originating from the own node is discarded.

In the ring selection method in the dual ring network system according to the next invention, in the above invention, in the transmission ring selection step, when the health check packet originated from the own node arrives from both rings,
The method is characterized by including a step of performing a predetermined calculation on a part or all of the identifier to obtain a random bit value, and selecting a ring determined according to the bit value as a transmission ring.

According to this invention, in the above invention,
In the transmission ring selection step, when the health check packet originating from the own node arrives from both rings, a random bit value is obtained by performing a predetermined calculation on a part or all of the identifier, and the bit value is set to the bit value. The ring determined accordingly is selected as the transmission ring.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a dual ring network system and a ring selection method according to the present invention will be described in detail below with reference to the accompanying drawings.

Embodiment 1. 1 is a block diagram showing the overall configuration of a dual ring network system according to a first embodiment of the present invention. In FIG. 1, the dual ring network system includes a dual ring 1 including a primary ring 11 and a secondary ring 12 having opposite directions.
The dual ring 1 is composed of a plurality of nodes 2-1 to 2-n which are connected to each other by using the transmission medium or the line. In the first embodiment, in this dual ring network system, the primary ring 11 or 2 is connected between arbitrary nodes.
Data packets and health check packets are transmitted and received through the next ring 12.

FIG. 2 shows an example of the internal structure of each node shown in FIG. As shown in FIG. 2, the node 20 includes ring interface units (ring I / F units) 21 and 22, a switch unit 23, a data packet processing unit 24, and a health check packet processing unit 25. Ring I / F part 2
1, 22 terminate the ring lines (primary ring 11 and secondary ring 12) connected to the ring ports 26, 27. The data packet processing unit 24 processes the data packet passed from the switch unit 23, and also the switch unit 23.
Process data packets to be passed to.

The health check packet processing unit 25 processes the health check packet passed from the switch unit 23, and also processes the health check packet passed to the switch unit 23. The health check packet is a packet for notifying other nodes of the health of the own node. Details of the processing will be described later.

The switch unit 23 refers to the packet type and the destination node ID described in the packet (data packet and health check packet), and the following (1) to (1) to
Packet exchange is performed as in (3). (1) Ring I /
When the packet arriving from the F units 21 and 22 is a health check packet or a data packet addressed to the own node, the data packet is passed to the data packet processing unit 24, and the health check packet is passed to the health check packet processing unit 25. (2) When the packet arriving from one of the ring I / F units 21 and 22 is a data packet addressed to another node, it is passed to the other of the ring I / F units 21 and 22. That is, relay it. (3) Ring I / O the data packet arriving from the data packet processing unit 24 and the health check packet arriving from the health check packet processing unit 25.
It is passed to the F sections 21 and 22 and sent to the double ring 1.

FIG. 3 shows an example of the structure of packets (data packet and health check packet). In FIG.
The packets (data packet and health check packet) adopted in the first embodiment are packet type 31 and T.
TL (Time To Live) 32, destination node ID 33, source node ID 34, check code 35, and packet data 36
It consists of and.

The packet type 31 is an identifier for identifying a data packet and a health check packet.
The TTL 32 is a packet remaining time for removing from the ring a packet that has no receiver because of the departure of the destination node or the like and that circulates infinitely. The source node fills in the initial value. A value equal to or larger than the number of nodes on the ring is used as the initial value. The relay node is TTL
Subtract one value. When a packet with TTL = 0 arrives at any node, the packet is discarded.

The destination node ID 33 is an identifier of the destination node. The destination node ID 33 is not used in the case of a health check packet. The transmission source node ID 34 is an identifier of the transmission source node. Check code 3
Reference numeral 5 is a code for checking the validity of each area of the packet at the relay node or the destination node. The packet data 36 is the body of the packet.

FIG. 4 shows an example of the structure of the receiving ring selection table. The receiving ring selection table adopted in the first embodiment describes the receiving ring 42 selected to receive the data packet for each source node ID 41. However, the contents differ for each node. It should be noted that this receiving ring selection table does not mean a table managed by software, but a transmission source node ID 41.
The receiving ring 42 selected for each is constituted by, for example, a group of flip-flops.

Next, the operation of each node will be described with reference to FIGS. Note that FIG. 5 is a flowchart illustrating the operation of generating the reception ring selection table based on the transmission / reception of the health check packet. FIG. 6 is a flow chart for explaining the data packet transmission / reception operation. FIG. 7 is a diagram for explaining the ring selection operation due to the occurrence of a failure. FIG. 8 is a diagram for explaining the contents of the reception ring selection table that is updated during the ring selection operation due to the occurrence of a failure.

First, the operation of generating the reception ring selection table will be described. In FIG. 5A, each node is a TTL.
The health check packet in which the value of 32 is entered is transmitted to both rings at a constant cycle (step ST1). Figure 5
In (2), each node refers to the source node ID 34 of the health check packet arriving from each ring (step ST2), and determines whether or not the arriving health check packet is the health check packet originating from the own node. Yes (step ST3). If the result of determination in step ST3 is that the health check packet originated from the own node (step ST3: Yes), discard processing is performed (step ST4). If the result of determination in step ST3 is a health check packet originating from another node (step ST3: No), the health check packet processing unit 25.
, The value of TTL32 is decremented by 1 and relayed along the ring (step ST5).

In FIG. 5 (3), each node monitors arrival / non-arrival of a health check packet originating from another node during a certain period in each relay node in the process of relaying (step ST6). As shown in the following (1) to (3), the presence / absence of a fault on the route is determined, and the contents of the reception ring selection table are generated or updated.

(1) When health check packets originating from other nodes arrive from both rings during a fixed period, both routes from the other node to the own node are judged to be normal. In this case, the reception ring selection table is set so that the ring on which the health check packet with the larger TTL value arrives becomes the reception ring of the data packet whose other node is the transmission source node (step ST
7). As a result, the data packet can be received from the ring having a small number of hops.

(2) When a health check packet originating from another node arrives from only one ring during a certain period, only the path from which the health check packet arrives out of both routes from the other node to the own node. It is judged to be normal. In this case, the reception ring selection table is set so that the ring on which the health check packet arrives is the reception ring of the data packet whose other node is the transmission source node (step ST8). As a result, when a failure occurs, the data packet can be received from the updated normal ring.

(3) If the health check packets originating from other nodes do not arrive from both rings during a certain period,
Both routes from the other node to the own node are determined to be abnormal. In this case, since it is impossible to receive the data packet whose other node is the transmission source node, the contents of the reception ring selection table are not updated (step ST
9).

Next, the data packet transmission / reception operation will be described. In FIG. 6 (1), each node transmits a data packet to both rings (step ST11). In FIG. 6 (2), each node refers to the destination node ID of the data packet arriving from each ring (step S
(T12), it is determined whether the packet is a data packet addressed to another node (step ST13). If the result of determination in step ST13 is a data packet addressed to another node (step ST13: Yes), the TTL value is decremented by 1 and relayed along the ring (step ST14).

On the other hand, if the result of determination in step ST13 is a data packet addressed to the own node (step ST1
3: No), referring to the source node ID of the data packet (step ST15), it is determined whether or not the ring that received the data packet matches the ring held in the reception ring selection table (step ST16). . If the result of determination in step ST16 is that they match (step ST16: Yes), the data packet is taken into the data packet processing unit 24 and reception processing is performed (step ST17). On the other hand, if the result of determination in step ST16 is that they do not match (step ST16: No), the data packet is discarded (step ST18).

Next, the ring selection operation due to the occurrence of a failure will be described. In FIG. 7, a dual ring network system in which five nodes 51 to 55 are connected via a dual ring 1 is shown. Here, while the node 53 is transmitting a data packet to the node 51 in the state before the disconnection shown in (a), the secondary ring 12 between the node 52 and the node 53 is disconnected as shown in (b). The ring selection operation in the case will be described. 8 shows the transition state of the reception ring selection table of the node 51, the transmission source node I
In the column of D41, # 1 is the I assigned to the node 51.
D and # 2 are IDs given to the node 52, # 3 are IDs given to the node 53, # 4 is ID given to the node 54, and # 5 is ID given to the node 55.

Before the disconnection (FIG. 7A), the health check packets from the nodes 52 to 55 arrive at the node 51 from both rings. Therefore, the reception ring selection table of the node 51 is shown in FIG. 8A. Is generated. Figure 8 (a)
Then, in the column of the receiving ring 42, the receiving ring for the node 51 (source node ID # 1) is not set, but the node 52 (source node ID # 2) and the node 53 (source node ID # 3) The receiving ring for
It is set as the secondary ring 12. Node 54 (source node ID # 4) and node 55 (source node ID #
The receiving ring for 5) is set as the primary ring 11.

At the time of transmitting / receiving a data packet, the node 5
Based on this receiving ring selection table, 1 takes in the data packet addressed to node 51 originating from secondary ring 12 and addressed to node 51, and discards the data packet originating from node 53 arriving from primary ring 11. The transmission / reception of the health check packet at a constant cycle is performed in parallel with the transmission / reception of the data packet.

Next, as shown in FIG. 7B, the node 52
When the secondary ring 12 between the node 53 and the node 53 is disconnected, health check packets from the node 52 arrive at the node 51 from both rings, but health check packets from the nodes 53 to 55 arrive from only the primary ring 11. To do. As a result, the reception ring selection table of the node 51 is shown in FIG.
As shown in (b), the node 53 (source node ID #
The receiving ring for 3) is updated to the primary ring 11. As for the nodes 52 (source node ID # 2), 54 (source node ID # 4), 55 (source node ID # 5), the result is the same as before the disconnection.

Therefore, when transmitting / receiving the data packet, the node 51 receives the node 53 from the primary ring 11 based on the updated receiving ring selection table.
A data packet addressed to the source node 51 will be captured. Since the secondary ring 12 is broken, the data packet originating from the node 53 does not arrive from the secondary ring 12.

As described above, according to the first embodiment, each node autonomously generates the reception ring selection table, promptly detects a change in the node configuration and the occurrence of a failure, and the reception ring selection table is autonomously detected. Can be reflected in a positive way. Therefore, it is not necessary to previously set a database in which each node stores the node connection order on the ring and the position of the own node in association with each other, which facilitates management.

Further, since each node autonomously generates or updates the reception ring selection table so that it can be received from a ring having a small number of hops, that is, a delay time is small for each combination of nodes, network performance can be facilitated. Can be improved.

Further, as can be understood from the above description, the ring selection process due to the occurrence of a fault is simple, and the hardware process is not suitable for the software process, and the hardware process is suitable, so that the speed of the ring selection can be easily realized. .

Embodiment 2. FIG. 9 is a flow chart for explaining a receiving ring selection table generating operation executed in the dual ring network system according to the second embodiment of the present invention. In the second embodiment, in the dual ring network system shown in FIG. 1, the health check packet remaining time (T
A method of generating a receiving ring selection table without using TL) is shown. The internal configuration of each node, the packet configuration, and transmission / reception are the same as in the first embodiment.
Here, a method of generating the receiving ring selection table according to the second embodiment will be described.

In FIG. 9, the same reference numerals are given to the processing procedures which are the same as or equivalent to the processing procedures shown in FIG. In FIG. 9 (1), each node transmits a health check packet to both rings at regular intervals (step ST21). In FIG. 9 (2), each node refers to the source node ID 34 of the health check packet arriving from each ring (step ST2), and when the arriving health check packet is the health check packet originating from the own node, (Step ST3: Yes),
A disposal process is performed (step ST4). If the packet is a health check packet originating from another node (step ST
3: No), unlike the first embodiment, the relay is performed along the ring as it is (step ST22).

In FIG. 9C, each node monitors arrival / non-arrival of the health check packet originating from another node during a certain period for each source node and for each ring (step S
T6) As shown in the following (1) to (3), the presence or absence of a fault on the route is determined, and the contents of the receiving ring selection table are generated or updated.

(1) When health check packets originating from other nodes arrive from both rings during a certain period, both routes from the other node to the own node are judged to be normal. In this case, unlike the first embodiment, the reception ring selection table is set such that the ring in which the health check packet arrives first is the reception ring of the data packet whose other node is the transmission source node ( Step ST23). As a result, a ring having a short transmission path distance or a ring having a wide band is selected as a data packet receiving ring. That is, since one ring where the health check packet arrives first has a shorter total transmission path distance than the other ring that arrives later, it can be said that one ring has a short delay time. Further, if the transmission band between the nodes is different for each section, the delay time between the two rings is different. Therefore, it may be said that one ring in which the health check packet arrives first has a short delay time.

(2) When a health check packet originating from another node arrives from only one ring during a certain period, only the path from which the health check packet arrives out of both routes from the other node to the own node. It is judged to be normal. In this case, as in the first embodiment, the reception ring selection table is set so that the ring on which the health check packet arrives is the reception ring of the data packet whose other node is the transmission source node (step S).
T8).

(3) If the health check packets originating from other nodes do not arrive from both rings during a certain period,
Both routes from the other node to the own node are determined to be abnormal. In this case, as in the first embodiment, since the data packet whose other node is the transmission source node cannot be received, the contents of the reception ring selection table are not updated (step ST9).

Therefore, according to the second embodiment, the same effect as that of the first embodiment can be obtained. In addition, the reception ring selection table is generated or updated so as to receive from the ring with a small delay time in consideration of not only the number of hops but also the distance and band of the transmission path, so that the network performance is further improved. be able to.

Embodiment 3. FIG. 10 is a diagram showing a configuration example of a transmission ring selection table adopted in the dual ring network system according to the third embodiment of the present invention.
In the third embodiment, in the dual ring network system shown in FIG. 1, ring selection at the time of failure or the like is performed by using a transmission ring selection table instead of the reception ring selection table shown in the first and second embodiments. A configuration example for performing the above is shown. The internal configuration of the node is the same as in FIG. 2, and the packet configuration is the same as in FIG. Here, the description will focus on the part related to the third embodiment.

As shown in FIG. 10, the transmission ring selection table adopted in the third embodiment describes the transmission ring 62 for transmitting the data packet for each destination node ID 61. The contents differ for each node. Note that this transmission ring selection table does not mean a table managed by software, but is composed of, for example, a group of flip-flops that holds the transmission ring 62 selected for each destination node ID 61.

Next, the operation of each node will be described with reference to FIGS. 11. FIG. 11 is a flowchart for explaining the operation of generating the transmission ring selection table based on the transmission / reception of the health check packet. FIG. 12 is a flowchart for explaining the data packet transmission / reception operation. FIG. 13 is a diagram for explaining the ring selection operation due to the occurrence of a failure. FIG. 14 is a diagram for explaining the contents of the transmission ring selection table that is updated during the ring selection operation due to the occurrence of a failure.

First, the operation of generating the transmission ring selection table will be described. In FIG. 11, the same reference numerals are given to the processing procedures that are the same as or equivalent to the processing procedures shown in FIG. Here, the description will focus on the part related to the third embodiment.

In FIG. 11A, each node has a TT
The health check packet in which the value of L32 is entered is transmitted to both rings at a constant cycle (step ST1). Figure 1
In 1 (2), each node refers to the source node ID 34 of the health check packet arriving from each ring (step ST2), and determines whether the arriving health check packet is the health check packet originating from the own node. A judgment is made (step ST3). If the result of determination in step ST3 is that the health check packet originated from the own node (step ST3: Yes), discard processing is performed (step ST4). If the result of determination in step ST3 is a health check packet originating from another node (step ST3: No), the health check packet processing unit 2
5, the value of TTL32 is decremented by 1 and relayed along the ring (step ST5).

In FIG. 11 (3), each node refers to the transmission source ID in the process of relaying, thereby arriving / sending the health check packet originating from the self node during a fixed period for each transmission source node and for each ring. Monitor non-arrival (step S
T6) As shown in the following (1) to (3), the presence or absence of a fault on the route is determined, and the contents of the transmission ring selection table are generated or updated.

(1) When health check packets originated from both nodes arrive from both rings during a fixed period, both rings are judged to be normal. In this case, TTL
The transmission ring selection table is set so that the ring on which the health check packet originating from another node having a smaller value arrives is set as the transmission ring of the data packet whose other node is the destination node (step ST31). The smaller TTL value of the arrived health check packet originating from another node means that the number of hops to the other node is smaller if traced backward from the own node. Therefore, the data packet can be transmitted from the ring having a small number of hops to the other node. Also, since the source node transmits only to one ring of the dual ring 1,
The transmission band on the rings can be used more effectively than when transmitting on both rings.

(2) When the health check packet originated from the own node arrives from only one ring during a certain period, only one ring is judged to be normal. In this case, the transmission ring selection table is set so that the ring on which the health check packet arrives is set as the transmission ring of the data packet, common to all the destination nodes (step S).
T32).

(3) When the health check packets originating from the own node do not arrive from both rings within a certain period,
Both rings are judged to be abnormal. In this case, the transmission ring selection table is set so that both rings are transmission rings for data packets, common to all destination nodes (step ST33).

Next, the data packet transmission / reception operation will be described. In FIG. 12 (1), each node transmits a data packet to the ring based on the transmission ring selection table (step ST41). The ring here is one ring. In FIG. 12 (2), in each node, since the data packet arrives from both rings, the destination node I of the data packet arriving from each ring
D33 is referred to (step ST42), and it is determined whether or not the packet is a data packet addressed to another node (step ST4).
3). If the result of determination in step ST43 is a data packet addressed to another node (step ST43: Ye
s), the TTL value is decremented by 1 and relayed along the ring (step ST44). On the other hand, if the result of determination in step ST43 is that the data packet is addressed to its own node (step ST43: No), it is taken into the data packet processing unit 24 and subjected to reception processing (step ST45).

As described above, since the data packet arrives from only one ring at the destination node, that is, the data packets do not arrive overlappingly from both rings, the discarding process (step ST18) shown in FIG. 6 does not occur. . That is, the transmission band on the ring can be effectively used.

Next, the ring selection operation due to the occurrence of a failure will be described. In FIG. 13, a dual ring network system in which five nodes 71 to 75 are connected via a dual ring 1 is shown. Here, while the node 73 is transmitting the data packet to the node 71 in the state before the disconnection shown in (a), the secondary ring 12 between the node 72 and the node 73 is disconnected as shown in (b). In this case, the ring selection operation when the primary ring 11 is disconnected in addition to the secondary ring 12 between the node 72 and the node 73 as shown in (c) will be described. 14 shows the transition state of the transmission ring selection table of the node 73. In the column of the destination node ID 61, # 1 is the ID given to the node 71, # 2 is the ID given to the node 72, #
3 is the ID given to the node 73, # 4 is the ID given to the node 74, and # 5 is the ID given to the node 75.

Before the disconnection (FIG. 13A), the health check packets from the nodes 71 to 75 arrive at the node 73 from both rings. In the node 73, each TTL value is compared for each transmission source node, and the transmission ring selection table of the node 73 is generated as shown in FIG. Figure 1
4 (a), in the column of the transmission ring 62, the node 7
The transmission ring for node 3 (destination node ID # 3) is not set, but the transmission rings for node 71 (destination node ID # 1) and node 72 (destination node ID # 2) are set as secondary ring 12. There is. Node 74 (destination node ID # 4) and node 75 (destination node ID #)
The transmission ring for 5) is set as the primary ring 11.

During the transmission / reception of data packets, the node 7
3 based on this transmission ring selection table, node 7
The data packet addressed to the 3-source node 71 is transmitted to the secondary ring 12. The node 71 takes in the data packet originating from the node 73, which arrives from the secondary ring 12. The transmission / reception of the health check packet at a constant cycle is performed in parallel with the transmission / reception of the data packet.

Next, as shown in FIG. 13B, when the secondary ring 12 between the node 72 and the node 73 is disconnected, the health check packet originated from the own node arrives at the node 73 only from the primary ring 11. . As a result, the transmission ring selection table of the node 73 has the node 71 (destination node ID # 1) and the node 72 as shown in FIG.
The transmission ring for (destination node ID # 2) is updated to the primary ring 11. Node 74 (destination node ID #
4) and 75 (destination node ID # 5) are the same as before the disconnection.

Therefore, the node 73 transmits the data packet addressed to the node 73 and the node 71 to the primary ring 11 based on the updated transmission ring selection table. The node 71 will take in the data packet from the node 73 arriving from the primary ring 11.

Further, as shown in FIG. 13C, when the primary ring 11 between the node 72 and the node 73 is broken and both rings are broken, the node 73 receives a health check packet from its own node. Not arriving from both rings.
As a result, the transmission ring selection table of the node 73 is, as shown in FIG.
# 1), node 72 (destination node ID # 2), node 7
4 (destination node ID # 4), node 75 (destination node I
The transmission rings for D # 5) are each the primary ring 1
Updated to primary & secondary ring 12.

The node 73 transmits the data packet addressed to the node 73 and the node 71 to both the rings based on the transmission ring selection table updated so that the both rings are the transmission rings. The node 71 takes in the data packet originating from the node 73, which arrives from the primary ring 11. The data packet originating from the node 73 does not arrive at the node 71 because the secondary ring 12 is disconnected.

Therefore, according to the third embodiment, the same effect as that of the first embodiment can be obtained. In addition, the transmission ring selection table is generated or updated so that the destination node can select and transmit a ring with a small number of hops for each combination of nodes, so that the transmission band on the ring can be used efficiently and The performance of can be further improved.

Fourth Embodiment FIG. 15 is a flow chart for explaining a transmission ring selection table generating operation executed in the dual ring network system according to the fourth embodiment of the present invention. The fourth embodiment shows a method for generating the transmission ring selection table without using the remaining time (TTL) of the health check packet described in the third embodiment in the dual ring network system shown in FIG. ing. That is, the fourth embodiment
Corresponds to the second embodiment. The internal configuration of each node, the configuration of packets, and transmission / reception are the same as in the third embodiment. Here, a method of generating the transmission ring selection table according to the fourth embodiment will be described.

In FIG. 15, the same or equivalent processing procedures as those shown in FIGS. 9 and 11 are designated by the same reference numerals. In FIG. 15 (1), each node transmits a health check packet to both rings at regular intervals (step ST21). In FIG. 15B, each node refers to the source node ID 34 of the health check packet arrived from each ring (step S
T2), it is determined whether or not the arrived health check packet is a health check packet originating from the own node (step ST3). If the result of determination in step ST3 is that the health check packet originated from the own node (step ST3: Yes), discard processing is performed (step ST).
4). If the result of determination in step ST3 is a health check packet originating from another node (step ST3
3: No), the health check packet originating from the other node is relayed as it is along the ring (step ST22).

In FIG. 15 (3), each node monitors arrival / non-arrival of the health check packet originated from its own node during a certain period for each source node and for each ring in the process of relaying (step ST6). As shown in the following (1) to (3), the presence / absence of a fault on the route is determined, and the contents of the transmission ring selection table are generated or updated.

(1) When the health check packets originated from both nodes arrive from both rings during a fixed period, both rings are judged to be normal. In this case, unlike the third embodiment, the transmission ring selection table is set such that the ring on which the health check packet arrives later is set as the transmission ring of the data packet whose other node is the destination node (step ST51). ). As a result, the data packet can be transmitted from the ring having a short delay time to the other node. Further, as in the third embodiment, the transmission source node transmits only to one ring of the dual ring 1, so that the transmission band on the ring can be used more effectively than when transmitting to both rings. become.

(2) When the health check packet originated from the own node arrives from only one ring during a certain period, only one ring is judged to be normal. In this case, as in the third embodiment, common to all destination nodes,
The transmission ring selection table is set so that the ring on which the health check packet arrives is the transmission ring of the data packet (step ST32).

(3) If the health check packet originated from both nodes does not arrive from both rings within a certain period,
Both rings are judged to be abnormal. In this case, similarly to the third embodiment, the transmission ring selection table is set so that both rings are transmission rings for data packets, common to all destination nodes (step ST33).

Therefore, according to the fourth embodiment, the same effect as that of the third embodiment can be obtained. In addition, the transmission ring selection table is generated or updated so as to transmit to a ring with a short delay time in consideration of not only the number of hops but also the distance and bandwidth of the transmission path, so that the transmission bandwidth on the ring is further improved. It can be used efficiently and the performance of the network can be further improved.

Embodiment 5. FIG. 16 is a diagram showing a configuration example of a data packet and a health check packet adopted in the dual ring network system according to the fifth embodiment of the present invention. In the fifth embodiment, a method of transmitting / receiving a data packet different from that described in the third embodiment or the fourth embodiment is shown. Others are the same as those in the third or fourth embodiment. Here, the description will focus on the part related to the fifth embodiment.

The packet adopted in the fifth embodiment is shown in FIG.
As shown in FIG. 6, a sequence number 81 is added to the packet structure shown in FIG. The sequence number 81 is a serial number sequentially assigned to the data packet for each source node. This sequence number 81
Is not used in the case of a health check packet.

Next, referring to the flowchart shown in FIG. 17, the data packet transmitting / receiving operation according to the fifth embodiment will be described. In FIG. 17 (1), each node transmits the data packet added with the sequence number 81 to the ring based on the transmission ring selection table (step ST61). In FIG. 17 (2), each node is
The destination node ID of the data packet arriving from each ring is referred to (step ST62), and it is determined whether the data packet is a data packet addressed to another node (step ST6).
3). If the result of determination in step ST63 is a data packet addressed to another node (step ST63: Yes
s), the TTL value is decremented by 1 and relayed along the ring (step ST64).

On the other hand, if the result of determination in step ST63 is that the data packet is addressed to its own node (step ST6
3: No), referring to the sequence number (step ST6)
5) It is determined whether or not the sequence number is larger than the sequence number of the same-node-originated data packet fetched immediately before (step ST66). If the result of determination in step ST66 is that the sequence number is larger than the sequence number of the same-node-originated data packet fetched immediately before (step ST66: Yes), there is a high possibility that it is the next data packet. The data is taken into the processing unit 24 and is received (step S
T67). On the other hand, as a result of the determination in step ST66, if the sequence number is equal to or smaller than the sequence number of the data packet from the same node fetched immediately before (step ST66: No), the duplicate arrival occurred in the transient state at the time of ring switching. Since there is a high possibility, it is discarded (step ST68).

Therefore, according to the fifth embodiment, the same effects as those of the third and fourth embodiments can be obtained.
In addition, since the data packet has the sequence number, the following excellent effects can be obtained. That is, the same data packet may arrive from both rings to the destination node in a duplicated manner until the change in the failure state of the network is reflected in the transmission ring selection table of each node.

Even in this case, according to the fifth embodiment, since the destination node can receive only one data packet by referring to the sequence number as described above, the reliability of the network is further improved. Can be made.

Although the fifth embodiment has been described with reference to the application example to the third or fourth embodiment, it can be similarly applied to the first or second embodiment, and the same. The effect of is obtained.

Sixth Embodiment FIG. 18 is a flow chart for explaining a data packet transmitting / receiving operation carried out in the dual ring network system according to the sixth embodiment of the present invention. In the sixth embodiment, a method of transmitting / receiving a data packet different from the method described in the third embodiment or the fourth embodiment is shown. Others are the same as those in the third or fourth embodiment. Here, the description will focus on the part relating to the sixth embodiment.

In FIG. 18A, each node has a TT
A health check packet in which L is entered or TTL is not entered is transmitted to both rings at a constant cycle (step ST71). In FIG. 18 (2), each node monitors the arrival status of a health check packet originating from another node during a certain period for each source node and for each ring by referring to the source ID (step ST72). It is determined whether or not the arrival situation has changed (step ST73).
If the result of determination in step ST73 is that there is no change (step ST73: No), the monitoring process is ended, but if there is change (step ST73: Yes).
s), recognizing that the fault condition on the route has changed, a data packet reception prohibited period of a fixed period is provided (step ST7).
After 4), the monitoring process ends.

Here, the fixed period in the data packet reception prohibition period set in step ST74 is the time from the occurrence of the change in the failure state to the distribution of the health check packet from each node to each node, and It is about 1 to 2 times. The above process is executed in the process of generating or updating the transmission ring selection table described above. After that, transmission / reception of the data packet is performed as follows.

In FIG. 18 (3), each node transmits the data packet to the ring based on the transmission ring selection table (step ST75). In FIG. 18 (4), each node refers to the destination node ID of the data packet arriving from each ring (step ST7).
6) It is determined whether the packet is a data packet addressed to another node (step ST77). If the result of determination in step ST77 is a data packet addressed to another node (step ST77: Yes), one is subtracted from the TTL value and relayed along the ring (step ST78).

On the other hand, if the result of determination in step ST77 is that the data packet is addressed to its own node (step ST7
7: No), first, it is determined whether or not the data packet reception prohibited period has been set (step ST79). If the result of determination in step ST79 is that the data packet reception prohibited period is not set (step ST79: No), reception processing is performed according to the procedure described above (step ST82).
When the data packet reception prohibited period is set (step ST79: Yes), it is then determined whether or not the current period is within the data packet reception prohibited period (step ST80).

If the result of determination in step ST80 is within the data packet reception prohibited period (step ST8).
0: Yes), the data packet addressed to the node that has arrived is discarded (step ST81). On the other hand, if the result of determination in step ST80 is outside the data packet reception prohibited period (step ST80: No), the arrived data packet addressed to its own node is fetched into the data packet processing unit 24 and reception processing is performed (step ST82).

Therefore, according to the sixth embodiment, the same effects as those of the third and fourth embodiments can be obtained.
In addition, since the change in the network failure state is actively monitored and the data packet reception prohibited period is set, the following excellent effects can be obtained. That is, the same data packet may arrive from both rings to the destination node in a duplicated manner until the change in the failure state of the network is reflected in the transmission ring selection table of each node.

Even in this case, according to the sixth embodiment, the data packet addressed to the own node from both destination nodes is forcibly discarded because it is within the data packet reception prohibited period as described above. As a result, it is possible to expect retransmission by the communication protocol of the upper layer,
The reliability of the network can be further improved.

In the sixth embodiment, an example of application to the third or fourth embodiment has been described, but the same can be applied to the first or second embodiment, and the same. The effect of is obtained. In addition, Embodiments 1 to 6
In the above, the data packet has a format in which the remaining time is added, but it goes without saying that the same can be applied to a data packet in which the remaining time is not added.

Seventh Embodiment 19 to 22 are diagrams for explaining a transmission / reception operation of a unicast data packet implemented in the dual ring network system according to the seventh embodiment of the present invention. It should be noted that FIG. 19 is a flowchart for explaining the transmission ring selection operation of the unicast data packet. FIG. 20 is a flow chart for explaining the receiving operation of the unicast data packet. Figure 21
FIG. 6 is a diagram for explaining a ring selection operation due to a failure occurrence. FIG. 22 is a diagram for explaining the relationship between the destination node ID and the transmission ring in the ring selection operation in FIG.

In the seventh embodiment, in the dual ring network system having the same configuration as shown in FIG.
A method is shown in which each node having the same configuration as shown in FIG. 2 selects a transmission ring of a unicast data packet, that is, a data packet in which the destination node is one node, based on the identifier of the destination node. The configurations of the unicast data packet and the health check packet are the same as those shown in FIG.

The operation related to the health check packet of each node is the same as that of each embodiment described above. Here, the operation related to the unicast data packet of each node will be described. First, with reference to FIG. 19, a unicast data packet transmission ring selection operation will be described. The processing procedure shown in FIG. 19 (steps ST90 to S90)
T93) corresponds to FIG. 5 (1) (2) or FIG. 9 (1) (2).
It is performed after the processing procedure described in 1. is performed.

In FIG. 19, each node monitors the arrival / non-arrival of a health check packet originating from itself during a fixed period for each source node and for each ring (step ST9).
0), as in the following (1) to (3), the presence / absence of a fault on the route is determined, and the transmission ring of the unicast data packet is selected.

(1) When the health check packets originated from both nodes arrive from both rings within a certain period, both rings are judged to be normal. In this case, each node refers to the destination node ID 33 of the unicast data packet to be transmitted, and, for example, the destination node ID 3
When the least significant bit of 3 is "0", the primary ring is selected, when it is "1", the secondary ring is selected, and the unicast data packet is transmitted to the corresponding ring (step ST91). . As a result, unicast data packets will be distributed on both rings depending on the destination node. It is needless to say that the bit position in the destination node ID 33 that is referred to in order to select the transmission ring does not have to be the least significant bit, and the bit at any position may be set as the reference bit.

(2) When the health check packet originating from the own node arrives from only one ring during a fixed period, only one ring is judged to be normal. In this case, each node selects the one ring determined to be normal and transmits the unicast data packet, regardless of the destination node ID 33 of the unicast data packet to be transmitted (step ST92).

(3) If the health check packet originated from both nodes does not arrive from both rings within a certain period,
Both rings are judged to be abnormal. In this case, each node selects both rings and transmits the unicast data packet regardless of the destination node ID 33 of the unicast data packet to be transmitted (step ST93).

Next, the operation of receiving a unicast data packet will be described with reference to FIG. In FIG. 20, each node refers to the destination node ID 33 of the unicast data packet arriving from each ring (step ST9).
5) It is determined whether the packet is a unicast data packet addressed to another node (step ST96). Step ST9
If the result of the determination in 6 is a unicast data packet addressed to another node (step ST96: Yes), the TTL value is decremented by 1 and relayed along the ring (step ST9).
7). On the other hand, if the result of determination in step ST96 is a unicast data packet addressed to the own node (step ST96
96: No), the receiving process of the unicast data packet is performed (step ST98).

Next, with reference to FIGS. 21 and 22, the transmission / reception operation described above will be specifically described in association with the occurrence of a ring failure. In FIG. 21, a dual ring network system in which five nodes 83 to 87 are connected via a dual ring 1 is shown. Here, as shown in (a), the state before disconnection, the state in which the secondary ring 12 between the nodes 84 and 85 is disconnected as shown in (b), and the node 84 and the node as shown in (c). In each of the states where the primary ring 11 between 85 is broken, the node 8
The transmitting / receiving operation when the node 5 transmits the unicast data packet to the node 83 and the node 83 receives the unicast data packet will be described.

As described above, in the seventh embodiment,
As a transmission ring selection rule, for example, the logical value of the least significant bit of the destination node ID 33 has meaning, and each node is determined according to the logical value of the least significant bit when both rings are healthy. I am trying to select a ring. In FIG. 22, a specific example of the transmission ring selection rule when the node 85 transmits to another node is shown.

As shown in FIG. 22, the ID of each node (destination node ID) is represented by a binary number having a digit number (3 digits in FIG. 22) capable of expressing all the nodes. That is, the ID of the node 83 is “001”. Since the least significant bit is "1", the node 85 selects the secondary ring as the transmission ring to the node 83. I at node 84
D is “010”. Since its least significant bit is "0", node 85 selects the primary ring as the transmit ring to node 84. The ID of the node 85 is “0
11 ”. The ID of the node 86 is“ 100 ”. Since the least significant bit is“ 0 ”, the node 85 is
Selects the primary ring as the transmit ring to node 86. The ID of the node 87 is “101”. Since its least significant bit is "1", node 85 will select the secondary ring as the transmit ring to node 87.

Now, in FIG. 21, before disconnection (see FIG.
In (a)), the health check packet originating from the node 85 arrives at the node 85 from both rings. In this case, the node 85 selects the transmission ring as shown in FIG. 22 according to the logical value of the least significant bit of the destination node ID 33 of the unicast data packet originating from the node 85. Here, since the packet is transmitted to the node 83, the node 85 transmits the unicast data packet addressed to the node 85 and sent to the node 83 to the unicast data packet 2.
Send to next ring 12. Node 83 is secondary ring 1
The reception processing of the unicast data packet originating from node 85 and arriving from node 2 from node 2 is performed.

Next, as shown in FIG. 21B, when the secondary ring 12 between the node 84 and the node 85 is disconnected, the health check packet originating from the node 85 is sent from the primary ring 11 only to the node 85. arrive. In this case,
The node 85 uses the primary ring 11 as a transmission ring regardless of the destination node ID 33 of the unicast data packet.
Select. That is, the node 85 transmits the unicast data packet addressed to the node 85 and the node 83 to the primary ring 11
Send to. The node 83 will receive the unicast data packet originating from the node 85 destined for itself, which has arrived from the primary ring 11.

Next, as shown in FIG. 21C, in a state where both the rings are broken, in which the primary ring 11 between the node 84 and the node 85 is broken, the health check packet from the node 85 is sent to the node 85. Not arriving from both rings. In this case, the node 85 selects both the primary ring 11 and the secondary ring 12 as the transmission ring regardless of the destination node ID 33 of the unicast data packet. That is, the node 85 transmits the unicast data packet addressed to the node 85 and the node 83 to both the primary ring 11 and the secondary ring 12. The unicast data packet addressed to the node 85 and destined for the node 83 does not arrive at the node 83 from the secondary ring 12 due to the disconnection, and arrives only from the primary ring 11. Therefore, the node 83
Is the node 85 addressed to the own node that has arrived from the primary ring 11.
Processing for receiving the outgoing unicast data packet will be performed.

As described above, according to the seventh embodiment, each node transmits a health check packet to promptly detect a change in the node configuration or the occurrence of a failure, and uses it as a transmission ring for a unicast data packet. A reachable ring can be quickly selected for each node. Therefore, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, which facilitates device management.

When both rings are normal, unicast data packets are distributed to both rings according to the destination node, so that the transmission band on the rings can be used efficiently and the network The performance can be easily improved.

Further, as can be understood from the above description, the ring selection process due to the occurrence of a failure is simple, the hardware process is not suitable for the software process, and the hardware process is suitable, so that the speed of the ring selection can be easily realized. .

Eighth Embodiment 23 to 25 are diagrams for explaining the transmission / reception operation of a multicast data packet implemented in the dual ring network system according to the eighth embodiment of the present invention. Note that FIG. 23 is a diagram showing a configuration example of the multicast data packet and the health check packet. FIG. 24 is a flowchart illustrating a transmission ring selection operation of a multicast data packet. FIG. 25 is a flowchart illustrating the operation of receiving a multicast data packet.

In the eighth embodiment, in the dual ring network system having the same configuration as shown in FIG.
A method is shown in which each node having the same configuration as shown in FIG. 2 selects a transmission ring of a multicast data packet, that is, a data packet in which the destination node is a plurality of nodes, based on an identifier for identifying a group of a plurality of destination nodes. Has been done.

The multicast data packet used in the eighth embodiment is, for example, as shown in FIG.
In the configuration shown in, a multicast connection ID 92 is provided instead of the destination node ID 33.
The other configurations are the same as those shown in FIG.

The multicast connection ID 92 is
It is an identifier for identifying a group of a plurality of destination nodes. Since the health check packet does not use this multicast connection ID 92, it has substantially the same configuration as that shown in FIG.

The operation related to the health check packet of each node is the same as that of each embodiment described above. Here, the operation related to the multicast data packet of each node will be described. First, referring to FIG.
The transmission ring selection operation of the multicast data packet will be described. The processing procedure shown in FIG. 24 (step ST10
0 to ST103) are shown in FIG. 5 (1) (2) or FIG.
(1) Performed after the processing procedure described in (2) is performed.

In FIG. 24, each node monitors the arrival / non-arrival of a health check packet originating from its own node during a fixed period for each source node and for each ring (step ST1
00), the presence / absence of a fault on the route is determined as in the following (1) to (3), and the transmission ring of the multicast data packet is selected.

(1) When health check packets originated from both nodes arrive from both rings during a certain period, both rings are judged to be normal. In this case, each node refers to the multicast connection ID 92 of the multicast data packet to be transmitted, selects the primary ring when the least significant bit of the multicast connection ID 92 is "0", and selects "1", for example. In this case, the secondary ring is selected and the multicast data packet is transmitted to the corresponding ring (step ST101).
As a result, the multicast data packet will be distributed to both rings depending on the destination node. It is needless to say that the bit position in the multicast connection ID referred to for selecting the transmission ring does not have to be the least significant bit, and the bit at any position may be set as the reference bit.

(2) When the health check packet originated from the own node arrives from only one ring during a fixed period, only one ring is judged to be normal. In this case, each node selects one of the rings determined to be normal and transmits the multicast data packet regardless of the multicast connection ID 92 of the multicast data packet to be transmitted (step ST10).
2).

(3) If the health check packets originating from the own node do not arrive from both rings within a certain period,
Both rings are judged to be abnormal. In this case, each node selects both rings and transmits the multicast data packet regardless of the multicast connection ID 92 of the multicast data packet to be transmitted (step ST103).

Next, the operation of receiving a multicast data packet will be described with reference to FIG. Note that, in FIG. 25, steps 105 to ST107 and ST111 are processing procedures in the switch unit 23. Step 108-S
T111 is a processing procedure in the data packet processing unit 24.

In FIG. 25, the switch unit 2 of each node
3 refers to the source node ID 34 of the multicast data packet arriving from each ring (step ST1
05), it is determined whether the packet is a multicast data packet originating from another node (step ST106). If the result of determination in step ST106 is that the multicast data packet originated from another node (step ST106: Ye
s), TTL value is decremented by 1, relayed along the ring, and taken in (step ST107). On the other hand, if the result of determination in step ST106 is that the multicast data packet originated from the own node (step ST106: N
o), the multicast data packet is discarded (step ST111).

Also, the data packet processing unit 2 of each node
4 refers to the multicast connection ID 92 of the multicast data packet fetched by the switch unit 23 (step ST108), and determines whether or not its own node is included in the group of destination nodes (step ST1).
09). If the result of determination in step ST109 is that the own node is included in the group of destination nodes (step ST109
109: Yes), the receiving process of the multicast data packet is performed (step ST110), and when it is not included (step ST109: No), the discard process of the multicast data packet is performed (step STST).
111).

As described above, according to the eighth embodiment, each node transmits a health check packet to quickly detect a change in the node configuration or the occurrence of a failure, and as a transmission ring of a multicast data packet, the destination node Each reachable ring can be quickly selected. Therefore, similarly to the seventh embodiment, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy.

When both rings are normal, the multicast data packet is distributed to both rings according to the destination node, so that the transmission band on the rings can be used efficiently as in the seventh embodiment. It is possible to improve the performance of the network easily.

Further, as can be understood from the above description, the ring selection process due to the occurrence of a failure is simple, and the hardware process is not suitable for the software process, and the hardware process is suitable, so that the speed of the ring selection can be easily realized. .

Ninth Embodiment 26 is a block diagram showing the configuration of a dual ring network system according to a ninth embodiment of the present invention. In FIG. 26, the dual ring network system includes a dual ring 1 including a primary ring 11 and a secondary ring 12 having opposite directions,
It is composed of a plurality of nodes 94-1 to 94-n which are connected to each other by using the dual ring 1 as a transmission medium or line.
Each node accommodates a plurality of terminals. That is, a plurality of terminals 95 are accommodated in the node 94-1. A plurality of terminals 96 are accommodated in the node 94-2. A plurality of terminals 97 are accommodated in the node 94-3. Node 9
A plurality of terminals 98 are accommodated in 4-4. Node 94
A plurality of terminals 99 are accommodated in -n.

FIG. 27 is a block diagram showing an example of the internal structure of the node shown in FIG. As shown in FIG. 27, the node 100 includes a ring interface unit (ring I / F).
Section) 101, 102, ring switch section 103, health check packet processing section 104, branch line switch section 105
And branch line interface section (branch line I / F section) 106-1 to
106-m.

The ring I / F units 101 and 102 terminate the ring lines (the primary ring 11 and the secondary ring 12) connected to the ring ports 107 and 108. Also, branch line I
/ F sections 106-1 to 106-m are branch line ports 109-
The terminal lines connected to 1 to 109-m are terminated.

The health check packet processing unit 104
The health check packet passed from the ring switch unit 103 is processed, and the health check packet passed to the ring switch unit 103 is processed. As described above, the health check packet is a packet for notifying other nodes of the soundness of the own node.

The ring switch section 103 uses the ring I / F section 10 on the basis of various information written at the beginning of the packet.
1, 102, the branch line switch unit 105, and the health check packet processing unit 104 exchange packets to be transferred.

The branch line switch unit 105 transfers between a plurality of branch line I / F units 106-1 to 106-m and the ring switch unit 103 based on a destination terminal ID described later at the beginning of the packet. Switch packets.

With such a configuration, each node exchanges a unicast data packet, which is a data packet, between a branch port that accommodates a terminal and a ring port that accommodates a ring line. Further, when transmitting / receiving a unicast data packet between the terminals, an operation of relaying the unicast data packet is performed between the nodes accommodating the terminals using the primary ring or the secondary ring.

FIG. 28 is a diagram showing a configuration example of a unicast data packet and a health check packet adopted in the ninth embodiment. As shown in FIG. 28, the unicast data packet adopted in the ninth embodiment has a destination terminal ID 110 instead of the destination node ID 33 in the configuration shown in FIG. Others are the same as the configuration shown in FIG. The destination terminal ID 110 is an identifier of the terminal connected to the destination node. Since this destination terminal ID 110 is not used in the health check packet, the health check packet has the same configuration as that shown in FIG.

The operation related to the health check packet of each node is the same as that of each embodiment described above. Here, the operation related to the unicast data packet of each node will be described with reference to FIGS. 29 and 30.
Note that FIG. 29 is a flowchart for explaining the transmission ring selection operation of the unicast data packet. Figure 30
6 is a flowchart illustrating a receiving operation of a unicast data packet.

First, with reference to FIG. 29, a transmission ring selecting operation of a unicast data packet will be described. FIG. 29
Processing procedure shown in (steps ST115 to ST118)
Is performed after the processing procedure described with reference to FIGS. 5 (1) and (2) or FIGS. 9 (1) and 9 (2).

In FIG. 29, each node monitors the arrival / non-arrival of a health check packet originating from itself during a fixed period for each source node and for each ring (step ST1).
15) As in the following (1) to (3), the presence / absence of a fault on the route is determined, and the transmission ring of the unicast data packet is selected.

(1) When the health check packets originated from both nodes arrive from both rings during a fixed period, both rings are judged to be normal. In this case, each node refers to the destination terminal ID 110 of the unicast data packet transmitted by switching from the branch port to the ring port. For example, when the least significant bit of the destination terminal ID 110 is "0", The primary ring is selected, and when it is "1", the secondary ring is selected and the unicast data packet is transmitted to the corresponding ring (step ST11).
6). As a result, unicast data packets will be distributed on both rings depending on the destination terminal. In addition,
Destination terminal ID 11 referred to for selecting the transmission ring
It goes without saying that the bit position at 0 does not have to be the least significant bit, and the bit at any position may be defined as the reference bit.

(2) When the health check packet originated from the own node arrives from only one ring during a certain period, only one ring is judged to be normal. In this case, each node selects one of the rings determined to be normal and transmits the unicast data packet, regardless of the destination terminal ID 110 of the unicast data packet to be transmitted by switching from the branch port to the ring port. Yes (step ST117).

(3) If the health check packet originated from both nodes does not arrive from both rings within a certain period,
Both rings are judged to be abnormal. In this case, each node has a destination terminal ID 110 of the unicast data packet to be transmitted by switching from the branch port to the ring port.
Irrespective of the above, both rings are selected and a unicast data packet is transmitted (step ST118).

Next, the operation of receiving a unicast data packet will be described with reference to FIG. Note that, in FIG. 30, steps 120 to ST122 and ST126 are processing procedures in the ring switch unit 103. Step 12
3 to ST126 are processing procedures in the branch line switch unit 105.

In FIG. 30, the ring switch section 103 of each node refers to the source node ID 34 of the unicast data packet arriving from each ring (step ST120), and determines whether the packet is a unicast data packet originating from another node. Is determined (step ST121). If the result of determination in step ST121 is a unicast data packet originating from another node (step ST121: Yes
s), the TTL value is decremented by 1, relayed along the ring, and taken in (step ST122). On the other hand, if the result of determination in step ST121 is a unicast data packet originating from the own node (step ST121: N
o), the unicast data packet is discarded (step ST126).

The branch line switch section 105 of each node
Refers to the destination terminal ID 110 of the unicast data packet captured by the ring switch unit 103 (step ST123), and determines whether or not it is addressed to the terminal accommodated by the own node (step ST124). Step ST1
As a result of the determination in step 24, if it is addressed to the terminal accommodated by the own node (step ST124: Yes), the unicast data packet is exchanged for the corresponding branch line port (step ST125) and not addressed to the terminal accommodated by the own node. In this case (step ST124: No), the unicast data packet is discarded (step ST12).
6).

As described above, according to the ninth embodiment, each node quickly detects a change in the node configuration or the occurrence of a failure by transmitting a health check packet, and uses it as a destination ring as a unicast data packet transmission ring. A reachable ring can be promptly selected for each terminal, that is, for each destination node. Therefore, similarly to the seventh and eighth embodiments, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node.
Device management becomes easy.

Further, each node accommodates a plurality of terminals,
Since the exchange is performed based on the destination terminal ID 110 of the unicast data packet, a larger-scale and flexible network can be constructed.

Further, as can be understood from the above description, the ring selection process due to the occurrence of a failure is simple, and the hardware process is not suitable for the software process, and the hardware process is suitable. Therefore, the speed of the ring selection can be easily realized. .

Tenth Embodiment 31 and 32 are flow charts for explaining the transmission / reception operation of the multicast data packet executed in the dual ring network system according to the tenth embodiment of the present invention. Note that FIG.
FIG. 1 is a flowchart illustrating a transmission ring selection operation of a multicast data packet. FIG. 32 is a flowchart illustrating the operation of receiving a multicast data packet.

In the tenth embodiment, in the dual ring network system having the same structure as shown in FIG. 26, each node having the same structure as shown in FIG.
There is shown a method of selecting the transmission ring of the multicast data packet data having the configuration shown in (1) on the basis of an identifier for identifying a group of a plurality of destination terminals.

That is, the multicast connection ID 9 in the multicast data packet shown in FIG.
2 is used as an identifier for identifying a group of a plurality of destination terminals in the tenth embodiment.

The operation related to the health check packet of each node is the same as that of each embodiment described above. Here, the operation related to the multicast data packet of each node will be described. First, referring to FIG. 31,
The transmission ring selection operation of the multicast data packet will be described. The processing procedure shown in FIG. 31 (step ST12
8 to ST131) are shown in FIG. 5 (1) (2) or FIG.
(1) Performed after the processing procedure described in (2) is performed.

In FIG. 31, each node monitors the arrival / non-arrival of a health check packet originating from its own node during a fixed period for each source node and for each ring (step ST1).
28), as in the following (1) to (3), the presence / absence of a fault on the route is determined, and the transmission ring of the multicast data packet is selected.

(1) When health check packets originated from both nodes arrive from both rings during a certain period, both rings are judged to be normal. In this case, each node refers to the multicast connection ID 92 of the multicast data packet transmitted by switching from the branch port to the ring port, and, for example, if the least significant bit of the multicast connection ID 92 is "0", it is set to 1 The next ring is selected, and if it is "1", the secondary ring is selected and the multicast data packet is transmitted to the corresponding ring (step ST129). As a result, the multicast data packet will be distributed to both rings depending on the destination terminal. It should be noted that the multicast connection ID 9 that is referred to in order to select the transmission ring
It is needless to say that the bit position in 2 does not have to be the least significant bit, and the bit at any position may be defined as the reference bit.

(2) When the health check packet originated from the own node arrives from only one ring during a certain period, only one ring is judged to be normal. In this case, each node selects one of the rings determined to be normal and transmits the multicast data packet, regardless of the multicast connection ID 92 of the multicast data packet transmitted by switching from the branch port to the ring port ( Step ST130).

(3) When the health check packet originated from the own node does not arrive from both rings within a certain period,
Both rings are judged to be abnormal. In this case, each node selects both rings and transmits the multicast data packet, regardless of the multicast connection ID 92 of the multicast data packet transmitted by switching from the branch port to the ring port (step ST1).
31).

Next, the operation of receiving a unicast data packet will be described with reference to FIG. Note that in FIG. 32, steps 133 to ST135 and ST139 are processing procedures in the ring switch unit 103. Step 13
6 to ST139 are processing procedures in the branch line switch unit 105.

In FIG. 32, the ring switch unit 103 of each node refers to the transmission source node ID 34 of the multicast data packet arriving from each ring (step ST133) and determines whether or not the multicast data packet originated from another node. Yes (step ST134).
If the result of determination in step ST134 is a multicast data packet originating from another node (step ST134:
Yes), the TTL value is decremented by 1, relayed along the ring, and fetched (step ST135). On the other hand, if the result of determination in step ST134 is that the multicast data packet originated from the own node (step ST13
4: No), discard processing of the multicast data packet is performed (step ST139).

The branch line switch unit 105 of each node
Is the multicast connection ID 9 of the multicast data packet captured by the ring switch unit 103.
2 (step ST136), it is determined whether or not the terminal accommodated by the own node is included in the group of destination terminals (step ST137). As a result of the determination in step ST137, when the terminal accommodated by the own node is included in the group of destination terminals (step ST137: Yes), the multicast data packet is exchanged for the corresponding branch line port (step ST138), and the own node When the terminal to be accommodated is not included in the group of destination terminals (step ST137: No), the multicast data packet is discarded (step ST139).

As described above, according to the tenth embodiment, each node quickly transmits a health check packet to detect a change in the node configuration or the occurrence of a failure, and as a transmission ring of the multicast data packet, the destination terminal Each reachable ring can be quickly selected. Therefore, similarly to the seventh to ninth embodiments, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy.

If both rings are normal, the multicast data packet is distributed to both rings according to the destination terminal, that is, the destination node.
Similarly, the transmission band on the ring can be used efficiently, and the performance of the network can be easily improved.

Further, since each node accommodates a plurality of terminals and exchanges based on the destination terminal ID of the multicast data packet, a larger-scale and flexible network can be constructed as in the ninth embodiment. .

In addition, as can be understood from the above description, the ring selection process due to the occurrence of a failure is simple, the hardware process is not suitable for the software process, and the hardware process is suitable, so that the speed of the ring selection can be easily realized. it can.

Eleventh Embodiment FIG. 33 is a flow chart for explaining a data packet transmission ring selecting operation carried out in the dual ring network system according to the eleventh embodiment of the present invention. In this eleventh embodiment,
A modified example of the method of selecting the transmission ring using the identifiers described in the seventh to tenth embodiments is shown.

That is, in FIG. 33, each node is
The arrival of health check packets originating from the own node from both rings is monitored during a fixed period (step ST14).
0). When the health check packet originating from the own node arrives from both rings, it is determined that both rings are normal. Then, a predetermined calculation such as odd parity is performed on part or all of the identifiers of the data packets to be transmitted,
A random 1-bit value that is uniquely determined is obtained (step ST141). Next, the logical value of the 1-bit value is judged (step ST142), and if 1-bit value = "0" (step ST142: Yes), for example, 1
The next ring is selected and transmitted (step ST143), while if the 1-bit value is not "0" (step ST1)
42: No), the secondary ring is selected and transmitted (step ST144).

Therefore, according to the eleventh embodiment, when both rings are normal, the probability of evenly distributing the data packets to both rings can be further improved, so that the transmission band on the rings can be made more efficient. Can be used to improve network performance.

[0202]

As described above, according to the present invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet indicating the remaining time to both rings and arrives. The node-originated health check packet is relayed along the ring after subtracting the remaining time, while the arrived node-originated health check packet is discarded. In the process of transmitting and receiving such a health check packet, the receiving ring selection means monitors the arrival / non-arrival of the health check packet originating from another node for each source node, and when it arrives from both rings, it remains. The ring in which the health check packet with a longer time arrives is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring is the receiving ring for the data packet originating from the other node. By selecting as, the relationship of the receiving ring with respect to the source node is obtained and held so that it can be updated. In this state, the data packet transmitting / receiving means transmits the data packet to both rings, and the arriving data packet addressed to another node is relayed along the ring, while the arriving data packet addressed to the own node is transmitted to the receiving ring selecting means. It is received or abandoned based on the content held in. In this way, each node autonomously generates the relationship of the receiving ring with respect to the source node and holds it so that it can be updated. Therefore, a change in the node configuration or the occurrence of a failure is promptly detected and held. The content can be reflected autonomously. Therefore, it is not necessary to preset the node connection order for each node, and the management becomes easy.
In addition, each node autonomously generates or updates the relationship of the receiving ring with respect to the source node so that it can receive from a ring with a large number of hops for each combination of nodes, that is, with a short delay time, which facilitates network performance. Can be improved. Further, since the ring selection process due to the occurrence of a failure is simple as described above, and the hardware process is not suitable for the software process and the hardware process is suitable, the speed of the ring selection can be easily realized.

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the receiving ring selection means monitors the arrival / non-arrival of the health check packet originating from another node for each source node, and when they arrive from both rings, the health check packet is sent. The ring in which the check packet arrives first is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring is selected as the receiving ring for the data packet originating from the other node. As a result, the relationship of the receiving ring with respect to the transmission source node is obtained, and the relationship is held so that it can be updated. In this state, the data packet transmitting / receiving means transmits the data packet to both rings, and the arriving data packet addressed to the other node is relayed along the ring, while the arriving data packet addressed to the own node is transmitted to the receiving ring selecting means. It is received or abandoned based on the content held in. In this way, when obtaining the relationship between the source node and the receiving ring, if the health check packets originating from other nodes arrive from both rings, the ring that arrives first is selected as the receiving ring, so only the number of hops is required. Instead, it is possible to generate or update the relationship of the receiving ring with respect to the source node so as to receive from the ring with the shortest delay time in consideration of the distance and band of the transmission path, which can further improve the network performance. .

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet indicating the remaining time to both rings, and the arrived health check packet originating from another node remains. While the time is subtracted and the packet is relayed along the ring, the arrived health check packet originating from its own node is discarded. In the process of transmitting and receiving such a health check packet, the table generation means monitors the arrival / non-arrival of the health check packet for each source node, and when the health check packet originating from the own node arrives from both rings. Selects a ring on which a health check packet with a shorter remaining time arrives for each transmission node as the transmission ring whose other node is the destination node, and when it arrives from only one ring, the one ring is If another node selects the transmission ring as the destination node and does not arrive from both rings, select both rings as the transmission ring common to all destination nodes, and the relationship of the transmission ring to the destination node is obtained and updated. Retained as possible. In this state, the data packet transmitting / receiving means transmits the data packet to both rings based on the content held by the transmission ring selecting means, and the arriving data packet addressed to the other node is relayed along the ring, while the arriving self packet arrives. The data packet addressed to the node is received. In this way, the relationship of the transmission ring with respect to the destination node is generated or updated so that the transmission source node can select and transmit a ring with a small number of hops for each combination of nodes.
As a result, when both rings are available, it is possible to select one ring with a smaller number of hops and transmit it, so that the transmission band on the rings can be used efficiently and the network performance is further improved. Can be made.

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting / receiving such a health check packet, the transmission ring selection means arrives / receives the health check packet for each source node.
If the arrival of the health check packet from the local node arrives from both rings, the ring where the health check packet arrives later for each sending node is selected as the sending ring of the data packet originating from the local node and addressed to the other node. ,
When arriving from only one ring, select the one ring as a transmission ring common to all destination nodes,
If the rings do not arrive from both rings, both rings are selected as common transmission rings for all the destination nodes, so that the relationship of the transmission rings with respect to the destination nodes is obtained and maintained so that they can be updated. In this state, the data packet transmitting / receiving means transmits the data packet to both rings based on the content held by the transmission ring selecting means, and the arriving data packet addressed to the other node is relayed along the ring, while the arriving self packet arrives. The data packet addressed to the node is received. In this way, when obtaining the relationship of the transmission ring to the destination node, if the health check packets originating from other nodes arrive from both rings, the ring that arrives later is selected as the transmission ring, so not only the number of hops, Considering the distance and bandwidth of the transmission path, the relationship of the transmission ring to the destination node can be created or updated so as to transmit to the ring with a short delay time, and the transmission bandwidth on the ring can be used more efficiently. Therefore, the network performance can be further improved.

According to the next invention, in the above invention, in the data packet transmitting / receiving means, the number adding means adds a serial number to the data packets to be transmitted to both rings. When the data packets arriving from both rings originate from the same node and have the same number and are data packets addressed to the own node, only the data packets arriving from one ring are received by the selective receiving means.
Thus, since the data packets are equipped with serial numbers,
Even if the same data packet arrives from both rings to the destination node redundantly until the change in the network failure status is reflected in the content of the relationship of the transmission ring to the destination node in each node By referring to the serial number, the node can receive only one data packet. Therefore, the reliability of the network can be further improved.

According to the next invention, in the above invention, in the process of transmitting / receiving the health check packet, the reception prohibition period setting means monitors the arrival status of the health check packet for each source node, When there is a change in the arrival status of check packets, a data packet reception prohibited period of a certain period is set. Then, in the operation process of the data packet transmitting / receiving means, the discarding means discards the data packet addressed to the own node which has arrived from both rings within the data packet reception prohibited period. In this way, the changes in the network failure status are actively monitored, and the data packet reception prohibited period is set. Even if the same data packet arrives from both rings to the destination node in duplicate until it is reflected on the destination node, the data packet addressed to its own node that arrives from both sides will be received at the destination node within the data packet reception prohibition period. It is forcibly discarded as it exists. As a result, since it is possible to expect retransmission by the communication protocol of the upper layer, it is possible to further improve the reliability of the network.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet indicating the remaining time is periodically transmitted to both rings, and the arrived health check packet originating from another node remains. While the time is subtracted and the packet is relayed along the ring, the arrived health check packet originating from its own node is discarded. In the process of transmitting and receiving such a health check packet, arrival / non-arrival of the health check packet originating from another node is monitored for each source node in the receiving ring selection step, and when the packet arrives from both rings, it remains. The ring in which the health check packet with more time arrives is selected as the receiving ring of the data packet originating from the other node,
When arriving from only one ring, the one ring is selected as the receiving ring of the data packet originating from the other node, and the relationship of the receiving ring with respect to the source node is obtained and held so that it can be updated. In this state, in the data packet transmission / reception step, the data packet is transmitted to both rings, and the arrived data packet addressed to the other node is relayed along the ring, while the arrived data packet addressed to the own node is transmitted to the reception ring selection table. It is received or discarded based on the setting. In this way, each node autonomously generates the relationship of the receiving ring with respect to the source node and holds it so that it can be updated, so that a change in the node configuration or the occurrence of a failure can be promptly detected,
It can be reflected autonomously in the retained content. Therefore, it is not necessary to preset the node connection order for each node, and the management becomes easy. In addition, each node autonomously generates or updates the relationship of the receiving ring with respect to the source node so that it can receive from a ring with a large number of hops for each combination of nodes, that is, with a short delay time, which facilitates network performance. Can be improved. Further, since the ring selection process due to the occurrence of a failure is simple as described above, and the hardware process is not suitable for the software process and the hardware process is suitable, the speed of the ring selection can be easily realized.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting / receiving such a health check packet, arrival / non-arrival of the health check packet originating from another node is monitored for each source node in the receiving ring selection step, and when the packet arrives from both rings, the health check packet is received. The ring in which the check packet arrives first is selected as the receiving ring for the data packet originating from the other node, and when it arrives from only one ring, the one ring is selected as the receiving ring for the data packet originating from the other node. As a result, the relationship of the receiving ring with respect to the transmission source node is obtained, and the relationship is held so that it can be updated. In this state, in the data packet transmitting / receiving step, the data packet is transmitted to both rings, and the arriving data packet addressed to the other node is relayed along the ring, while the arriving data packet addressed to the own node is transmitted to the reception ring selection table. It is received or discarded based on the setting. In this way, when obtaining the relationship between the source node and the receiving ring, if the health check packets originating from other nodes arrive from both rings, the ring that arrives first is selected as the receiving ring, so only the number of hops is required. Instead, it is possible to generate or update the relationship of the receiving ring with respect to the source node so as to receive from the ring with the shortest delay time in consideration of the distance and band of the transmission path, which can further improve the network performance. .

According to the next invention, in each node, in the health check packet transmission / reception process, the health check packet indicating the remaining time is periodically transmitted to both rings, and the arrived health check packet originating from another node is ringed. The health check packet arriving from its own node is discarded while being relayed along. When such a health check packet is transmitted and received, the arrival / non-arrival of the health check packet is monitored for each source node in the transmission ring selection step, and the health check packet originating from the own node arrives from both rings. , The ring on which the health check packet with less remaining time arrives for each sending node is selected as the sending ring for the data packet destined for the other node destined for the own node. If the ring is selected as the common transmission ring for all destination nodes and if it does not arrive from both rings, both rings are selected as the common transmission ring for all destination nodes so that the relationship of the transmission ring to the destination node is the transmission ring. It is set in the selection table. In this state, in the data packet transmission / reception step, the data packet is transmitted to both rings based on the contents held in the transmission ring selection step, and the arrived data packet addressed to another node is relayed along the ring and arrived. The data packet addressed to the own node is received. In this way, the relationship of the transmission ring with respect to the destination node is generated or updated so that the transmission source node can select and transmit a ring with a small number of hops for each combination of nodes. As a result, when both rings are available, it is possible to select one ring with a smaller number of hops and transmit it, so that the transmission band on the rings can be used efficiently and the network performance is further improved. Can be made.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, in the transmission ring selection step, the arrival / non-arrival of the health check packet for each source node is performed.
If the arrival of the health check packet from the local node arrives from both rings, the ring where the health check packet arrives later for each sending node is selected as the sending ring of the data packet originating from the local node and addressed to the other node. ,
When arriving from only one ring, select the one ring as a transmission ring common to all destination nodes,
If the rings do not arrive from both rings, both rings are selected as common transmission rings for all the destination nodes, so that the relationship of the transmission rings with respect to the destination nodes is obtained and maintained so that they can be updated. In this state, in the data packet transmission / reception step, the data packet is transmitted to both rings based on the contents held in the transmission ring selection step, and the arrived data packet addressed to another node is relayed along the ring and arrived. The data packet addressed to the own node is received. In this way, when obtaining the relationship of the transmission ring to the destination node, if the health check packets originating from other nodes arrive from both rings, the ring that arrives later is selected as the transmission ring, so not only the number of hops, Considering the distance and bandwidth of the transmission path, the relationship of the transmission ring to the destination node can be created or updated so as to transmit to the ring with a short delay time, and the transmission bandwidth on the ring can be used more efficiently. Therefore, the network performance can be further improved.

According to the next invention, in the above invention, in the data packet transmitting / receiving step, the serial number is added to the data packet to be transmitted to both rings in the number adding step. Then, in the selective reception step, when the data packets arriving from both rings originate from the same node and have the same number and are data packets addressed to the own node, only the data packets arriving from one ring are received.
Thus, since the data packets are equipped with serial numbers,
Until the change in the network failure status is reflected in the content of the relationship between the source node and the receiving ring and the relationship between the destination node and the transmitting ring in each node, the same data packet is duplicated from both rings to the destination node. Even when the data arrives as a result, the destination node can receive only one data packet by referring to the serial number. Therefore, the reliability of the network can be further improved.

According to the next invention, in the above invention, in the process of transmitting / receiving the health check packet, the arrival status of the health check packet is monitored for each source node in the reception prohibited period setting step, When there is a change in the arrival status of check packets, a data packet reception prohibited period of a certain period is set. Then, in the data packet transmitting / receiving step, in the discarding step,
The data packet addressed to the own node which has arrived from both rings within the data packet reception prohibition period is discarded. In this way, the changes in the network failure status are actively monitored, and the data packet reception prohibited period is set. Therefore, changes in the network failure status can be determined by the relationship between the receiving ring with respect to the source node and the destination at each node. Even if the same data packet arrives from both rings to the destination node in duplicate until it is reflected in the content held in the relationship of the transmission ring to the node, the destination node will receive the data packet addressed to both nodes at the destination node. However, it is forcibly discarded because it is within the data packet reception prohibited period. As a result, since it is possible to expect retransmission by the communication protocol of the upper layer, it is possible to further improve the reliability of the network.

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting / receiving such a health check packet, arrival / non-arrival of the health check packet originated from the own node is monitored by the transmission ring selection means for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the unicast data packet to be transmitted is selected as the transmission ring and arrives from only one ring. If so, one of the rings is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, the data packet transmitting / receiving means transmits the unicast data packet to the ring based on the selection result. Then, the arrived unicast data packet addressed to another node is relayed along the ring. In addition, the unicast data packet addressed to the own node is received and processed. In this way, each node quickly transmits a health check packet to detect changes in the node configuration and the occurrence of failures, and promptly selects a reachable ring for each destination node as the unicast data packet transmission ring. Since it is possible to do so, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy. Also, when both rings are normal, unicast data packets are distributed to both rings according to the destination node, so that the transmission band on the rings can be used efficiently and network performance is facilitated. Can be improved.

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting / receiving such a health check packet, arrival / non-arrival of the health check packet originated from the own node is monitored by the transmission ring selection means for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node group identifier that identifies the group of the plurality of destination nodes of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, the data packet transmitting / receiving means transmits the multicast data packet to the ring based on the selection result. Then, the arrived multi-node originated multicast data packet is relayed along the ring and received. In addition, the arrived multicast data packet originating from the own node is discarded. In this way, each node transmits a health check packet to promptly detect a change in the node configuration or the occurrence of a failure, and promptly selects a reachable ring for each destination node as the transmission ring of the multicast data packet. Therefore, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy. Further, when both rings are normal, the multicast data packet is distributed to both rings according to the destination node, so that the transmission band on the rings can be efficiently used as in the case of the seventh embodiment. It is possible to improve the performance of the network easily.

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting / receiving such a health check packet, arrival / non-arrival of the health check packet originated from the own node is monitored by the transmission ring selection means for each source node. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted is selected as the transmission ring,
If the ring arrives from only one ring, the one ring is selected as a transmission ring, and if the ring does not arrive from both rings, both rings are selected as a transmission ring. As a result, the data packet transmitting / receiving means transmits the unicast data packet sent from the accommodated terminal to the ring based on the selection result. Then, the unicast data packet arriving from another node is relayed along the ring, and when the unicast data packet is addressed to the terminal accommodated by the own node, the unicast data packet is relayed to the accommodated terminal. Further, the unicast data packet originating from the own node that has arrived is discarded. In this way, each node transmits a health check packet to quickly detect a change in the node configuration or the occurrence of a failure, and as a transmission ring for a unicast data packet, a ring reachable for each destination terminal, that is, for each destination node. Since it is possible to quickly select, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, which facilitates device management.
Moreover, since each node accommodates a plurality of terminals and exchanges based on the destination terminal identifier of the unicast data packet, a larger-scale and flexible network can be constructed.

According to the next invention, in each node, the health check packet transmitting / receiving means periodically transmits the health check packet to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting / receiving such a health check packet, arrival / non-arrival of the health check packet originated from the own node is monitored by the transmission ring selection means for each source node. When arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal group identifier that identifies the group of the plurality of destination terminals of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, the data packet transmitting / receiving means transmits the multicast data packet transmitted from the terminal to be accommodated to the ring based on the selection result. And
The arrived multicast data packet originating from another node is relayed along the ring, and when it is addressed to the terminal accommodated by the own node, the multicast data packet is relayed to the accommodated terminal. In addition, the arrived multicast data packet originating from the own node is discarded. In this way, each node transmits a health check packet to quickly detect a change or failure in the node configuration, and promptly selects a reachable ring for each destination terminal as a multicast data packet transmission ring. Therefore, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy. Also, when both rings are normal, multicast data packets are distributed to both rings according to the destination terminal, that is, the destination node, so that the transmission band on the rings can be used efficiently and the network performance is improved. Can be easily improved.

According to the next invention, in the above invention, in the transmission ring selection means, when the health check packet originating from the own node arrives from both rings, a predetermined calculation is performed for a part or all of the identifier. A random bit value is obtained by performing the operation, and a ring determined according to the bit value is selected as a transmission ring. Therefore, when both rings are normal, the probability of evenly distributing the data packets to both rings can be further improved, so that the transmission band on the rings can be used more efficiently and the network performance can be improved. It can be easily improved.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the arrival / non-arrival of the health check packet originating from the own node is monitored for each source node in the transmission ring selection step. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the unicast data packet to be transmitted is selected as the transmission ring and arrives from only one ring. If so, one of the rings is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, in the data packet transmitting / receiving step, the unicast data packet is transmitted to the ring based on the selection result. Then, the arrived unicast data packet addressed to another node is relayed along the ring. In addition, the unicast data packet addressed to the own node is received and processed. In this way, each node quickly transmits a health check packet to detect changes in the node configuration and the occurrence of failures, and promptly selects a reachable ring for each destination node as the unicast data packet transmission ring. Since it is possible to do so, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy. Also, when both rings are normal, unicast data packets are distributed to both rings according to the destination node, so that the transmission band on the rings can be used efficiently and network performance is facilitated. Can be improved.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the arrival / non-arrival of the health check packet originating from the own node is monitored for each source node in the transmission ring selection step. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination node group identifier that identifies the group of the plurality of destination nodes of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, in the data packet transmitting / receiving step, the multicast data packet is transmitted to the ring based on the selection result. Then, the arrived multi-node originated multicast data packet is relayed along the ring and received. In addition, the arrived multicast data packet originating from the own node is discarded. In this way, each node transmits a health check packet to promptly detect a change in the node configuration or the occurrence of a failure, and promptly selects a reachable ring for each destination node as the transmission ring of the multicast data packet. Therefore, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy. Further, when both rings are normal, the multicast data packet is distributed to both rings according to the destination node, so that the transmission band on the rings can be efficiently used as in the case of the seventh embodiment. It is possible to improve the performance of the network easily.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the arrival / non-arrival of the health check packet originating from the own node is monitored for each source node in the transmission ring selection step. Then, when arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted is selected as the transmission ring,
If the ring arrives from only one ring, the one ring is selected as a transmission ring, and if the ring does not arrive from both rings, both rings are selected as a transmission ring. As a result, in the data packet transmitting / receiving step, the unicast data packet transmitted from the accommodating terminal is transmitted to the ring based on the selection result. Then, the unicast data packet arriving from another node is relayed along the ring, and when the unicast data packet is addressed to the terminal accommodated by the own node, the unicast data packet is relayed to the accommodated terminal. Further, the unicast data packet originating from the own node that has arrived is discarded. In this way, each node transmits a health check packet to quickly detect a change in the node configuration or the occurrence of a failure, and as a transmission ring for a unicast data packet, a ring reachable for each destination terminal, that is, for each destination node. Since it is possible to quickly select, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, which facilitates device management.
Moreover, since each node accommodates a plurality of terminals and exchanges based on the destination terminal identifier of the unicast data packet, a larger-scale and flexible network can be constructed.

According to the next invention, in each node, in the health check packet transmitting / receiving step, the health check packet is periodically transmitted to both rings, and the arrived health check packet originating from another node is relayed along the ring. On the other hand, the arrived health check packet originating from the own node is discarded. In the process of transmitting and receiving such a health check packet, the arrival / non-arrival of the health check packet originating from the own node is monitored for each source node in the transmission ring selection step. When arriving from both rings, the ring determined according to the logical value of the bit at the predetermined bit position of the destination terminal group identifier that identifies the group of the plurality of destination terminals of the multicast data packet to be transmitted is the transmission ring. If one ring is selected and arrives from only one ring, the one ring is selected as a transmission ring, and if no ring arrives from both rings, both rings are selected as transmission rings. As a result, in the data packet transmission / reception step, the multicast data packet transmitted from the accommodating terminal is transmitted to the ring based on the selection result. And
The arrived multicast data packet originating from another node is relayed along the ring, and when it is addressed to the terminal accommodated by the own node, the multicast data packet is relayed to the accommodated terminal. In addition, the arrived multicast data packet originating from the own node is discarded. In this way, each node transmits a health check packet to quickly detect a change or failure in the node configuration, and promptly selects a reachable ring for each destination terminal as a multicast data packet transmission ring. Therefore, it is not necessary to previously set a database in which the node connection order on the ring and the position of the own node are set in each node, and the device management becomes easy. Also, when both rings are normal, the multicast data packets are distributed to both rings according to the destination terminal, that is, the destination node, so that the transmission band on the rings can be used efficiently and the network performance is improved. Can be easily improved.

According to the next invention, in the above invention, in the transmission ring selection step, when the health check packet originated from the own node arrives from both rings, a predetermined calculation is performed for a part or all of the identifier. A random bit value is obtained by performing the operation, and a ring determined according to the bit value is selected as a transmission ring. Therefore, when both rings are normal, the probability of evenly distributing the data packets to both rings can be further improved, so that the transmission band on the rings can be used more efficiently and the network performance can be improved. It can be easily improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a dual ring network system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration example of a node shown in FIG.

FIG. 3 is a diagram showing a configuration example of a data packet and a health check packet adopted in the first embodiment.

FIG. 4 is a diagram showing a configuration example of a receiving ring selection table adopted in the first embodiment.

FIG. 5 is a flowchart illustrating a receiving ring selection table generation operation based on transmission / reception of a health check packet according to the first embodiment.

FIG. 6 is a flowchart illustrating a data packet transmission / reception operation according to the first embodiment.

FIG. 7 is a diagram illustrating a ring selection operation due to a failure occurrence according to the first embodiment.

FIG. 8 is a diagram for explaining the contents of a reception ring selection table that is updated during a ring selection operation due to the occurrence of a failure according to the first embodiment.

FIG. 9 is a flowchart illustrating a receiving ring selection table generating operation performed in the dual ring network system according to the second embodiment of the present invention.

FIG. 10 is a diagram showing a configuration example of a transmission ring selection table adopted in the dual ring network system according to the third embodiment of the present invention.

FIG. 11 is a flowchart illustrating an operation of generating a transmission ring selection table based on transmission / reception of health check packets according to the third embodiment.

FIG. 12 is a flowchart illustrating a data packet transmission / reception operation according to the third embodiment.

FIG. 13 is a diagram illustrating a ring selection operation due to the occurrence of a failure according to the third embodiment.

FIG. 14 is a diagram illustrating the contents of a transmission ring selection table that is updated at the time of ring selection operation due to the occurrence of a failure according to the third embodiment.

FIG. 15 is a flowchart illustrating a transmission ring selection table generating operation performed in the dual ring network system according to the fourth embodiment of the present invention.

FIG. 16 is a diagram showing a configuration example of a data packet and a health check packet adopted in the dual ring network system according to the fifth embodiment of the present invention.

FIG. 17 is a flowchart illustrating a data packet transmission / reception operation according to the fifth embodiment.

FIG. 18 is a flowchart illustrating a data packet transmission / reception operation performed in the dual ring network system according to the sixth embodiment of the present invention.

FIG. 19 is a flowchart illustrating a transmission ring selection operation of a unicast data packet, which is performed in the dual ring network system according to the seventh embodiment of the present invention.

FIG. 20 is a flowchart illustrating a unicast data packet receiving operation performed in the dual ring network system according to the seventh embodiment of the present invention.

FIG. 21 is a diagram illustrating a ring selection operation due to a failure occurrence according to the seventh embodiment.

22 is a diagram illustrating a relationship between a destination node ID and a transmission ring in the ring selection operation in FIG.

FIG. 23 is a diagram showing a configuration example of a multicast data packet and a health check packet adopted in the dual ring network system according to the eighth embodiment of the present invention.

FIG. 24 is a flowchart illustrating a transmission ring selection operation of a multicast data packet, which is carried out in the dual ring network system according to the eighth embodiment of the present invention.

FIG. 25 is a flowchart illustrating a multicast data packet receiving operation performed in the dual ring network system according to the eighth embodiment of the present invention.

FIG. 26 is a block diagram showing a configuration of a dual ring network system which is Embodiment 9 of the present invention.

FIG. 27 is a block diagram showing an example of the internal configuration of the node shown in FIG. 26.

FIG. 28 is a diagram showing a configuration example of a unicast data packet and a health check packet adopted in the ninth embodiment.

FIG. 29 is a flowchart illustrating a unicast data packet transmission ring selection operation carried out in the dual ring network system according to the ninth embodiment of the present invention.

FIG. 30 is a flowchart illustrating a unicast data packet receiving operation performed in the dual ring network system according to the ninth embodiment of the present invention.

[Fig. 31] Fig. 31 is a flowchart illustrating a transmission ring selection operation of a multicast data packet, which is performed in the dual ring network system according to the tenth embodiment of the present invention.

[Fig. 32] Fig. 32 is a flowchart illustrating a reception operation of a multicast data packet implemented in the dual ring network system according to the tenth embodiment of the present invention.

[Fig. 33] Fig. 33 is a flowchart for explaining a transmission ring selection operation of a data packet, which is performed in the dual ring network system according to the eleventh embodiment of the present invention.

FIG. 34 is a diagram showing a configuration example of a conventional dual ring network system.

FIG. 35 is a block diagram showing an internal configuration of the conventional node shown in FIG. 34.

[Explanation of symbols]

1 double ring, 2-1 to 2-n, 20, 51 to 55,
71-75, 83-87, 94-1-94-n, 100
Node, 11 primary ring, 12 secondary ring, 2
1, 22, 101, 102 ring interface unit (ring I / F unit), 23 switch unit, 24 data packet processing unit, 25, 104 health check packet processing unit, 26, 27, 107, 108 ring port, 95 to 99 Multiple terminals, 103 ring switch section, 105 branch line switch section, 106-1 to 106-m
Branch line interface section (branch line I / F section), 109-1
~ 109-m Branch line port, 33 Destination node ID, 9
2 Multicast connection ID, 110 Destination terminal ID.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasutaka Negumi             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Toshihiro Shika             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F term (reference) 5K031 AA07 AA09 AA10 CB09 CB12                       DA12 EA04

Claims (22)

[Claims] 1. A dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions, wherein the plurality of nodes are , A health check packet with remaining time is periodically sent to both rings, and the remaining time of the health check packet from another node that arrives is subtracted and relayed along the ring, while the health check packet from its own node arrives. In the process of transmitting and receiving the health check packet with the health check packet transmitting and receiving means for discarding, the arrival / non-arrival of the health check packet originating from another node is monitored for each source node, and when arrival from both rings, Receive the data packet originating from the other node on the ring where the health check packet with more remaining time arrives When it is selected as a ring and arrives from only one ring, the one ring is selected as the receiving ring of the data packet originating from the other node, and the relationship of the receiving ring with respect to the transmission source node is obtained and held as updatable. Receiving ring selecting means for transmitting data packets to both rings, relaying the arriving data packet addressed to another node along the ring, and arriving the own node data packet based on the contents held by the receiving ring selecting means. A dual ring network system comprising: a data packet transmitting / receiving means for receiving or discarding. 2. A dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions, wherein the plurality of nodes are , Periodically send health check packets to both rings,
A health check packet transmission / reception means for discarding a health check packet originating from its own node while relaying a health check packet originating from another node along the ring, and for each source node in the process of transmitting / receiving the health check packet. The arrival / non-arrival of the health check packet originated from another node is monitored in the above. When the health check packet arrives from both rings, the ring in which the health check packet arrives first is selected as the receiving ring of the data packet originated from the other node, and one of the rings is received. When arriving from only a ring, by selecting one of the rings as a receiving ring of the data packet originating from the other node, a receiving ring selecting unit that obtains the relationship of the receiving ring with respect to the source node and holds it updatable, Data addressed to another node that arrived by sending data packets to both rings And a data packet transmitting / receiving means for relaying the packet along the ring and receiving or discarding the arriving data packet addressed to the own node based on the content held in the receiving ring selecting means. system. 3. A dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions, wherein the plurality of nodes are , A health check packet with remaining time is periodically sent to both rings, and the remaining time of the health check packet from another node that arrives is subtracted and relayed along the ring, while the health check packet from its own node arrives. In the process of transmitting and receiving the health check packet with the health check packet transmitting and receiving means, the arrival / non-arrival of the health check packet is monitored for each source node, and the health check packet originating from the own node arrives from both rings. In this case, the health check packet with less remaining time arrives for each sending node. Ring is selected as the transmission ring of the data packet in which the other node is the destination node, and when it arrives from only one ring, that one ring is selected as the transmission ring common to all the destination nodes, and both rings are selected. If they do not arrive, both rings are selected as common transmission rings to all destination nodes, and the transmission ring selection means for determining the relationship of the transmission rings with respect to the destination nodes and holding it updatable, and selecting the data packet as the transmission ring. Data packet transmitting / receiving means for transmitting to both rings based on the content held by the means, relaying the arrived data packet addressed to another node along the ring, and receiving the arrived data packet addressed to its own node. And dual ring network system. 4. A dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions, wherein the plurality of nodes are , Periodically send health check packets to both rings,
A health check packet transmission / reception means for discarding a health check packet originating from its own node while relaying a health check packet originating from another node along the ring, and for each source node in the process of transmitting / receiving the health check packet. The arrival / non-arrival of the health check packet is monitored at each node, and when the health check packet originating from the own node arrives from both rings, the other node is the destination node of the ring after which the health check packet arrives for each transmitting node. Select it as the transmission ring for data packets,
When arriving from only one ring, select the one ring as a transmission ring common to all destination nodes,
If the packets do not arrive from both rings, both rings are selected as a common transmission ring to all destination nodes to obtain the relationship between the transmission rings with respect to the destination nodes, and the transmission ring selecting means for holding the data packet in an updatable manner is used. Data packet transmission / reception means for transmitting to both rings based on the content held by the transmission ring selection means, relaying the arrived data packet addressed to another node along the ring, and receiving the arrived data packet addressed to its own node. A dual ring network system characterized in that 5. The data packet transmission / reception means, the number addition means for adding a serial number to the data packets transmitted to both rings, and the data packets arriving from both rings originate from the same node and have the same number. 5. The dual ring network according to any one of claims 1 to 4, further comprising: selective receiving means for receiving only a data packet arriving from one of the rings when the data packet is a destination data packet. system. 6. In the process of transmitting and receiving the health check packet, the arrival status of the health check packet is monitored for each source node, and when the arrival status of the health check packet changes, data packet reception is prohibited for a certain period. A reception prohibition period setting means for setting a period; and a discarding means for discarding a data packet addressed to its own node that has arrived from both rings within the data packet reception prohibition period in the operation process of the data packet transmission / reception means. The dual ring network system according to any one of claims 1 to 4, characterized in that: 7. A ring selection method in a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. , The plurality of nodes periodically transmits a health check packet indicating the remaining time to both rings, subtracts the remaining time of the arrived health check packet from another node, and relays along the ring while arriving. The health check packet transmitting / receiving step of discarding the health check packet originating from the local node and the arrival / non-arrival of the health check packet originating from another node are monitored for each source node in the process of transmitting / receiving the health check packet. If it arrives from, the ring where the health check packet with more remaining time arrived arrives When a ring arrives from only one ring, the one ring is selected as the receiving ring of the data packet originating from the other node, and the relation of the receiving ring to the source node is selected. And a process for selecting a receiving ring for holding the data so that it can be updated, and transmitting a data packet to both rings and relaying the data packet addressed to another node along the ring, while selecting the data packet addressed to the own node for the reception ring. A method of selecting a ring in a dual ring network system, comprising: a data packet transmitting / receiving step of receiving or discarding based on contents held in the step. 8. A ring selection method in a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. , The plurality of nodes side periodically transmits a health check packet to both rings,
A health check packet transmission / reception process of discarding the health check packet originating from the own node while relaying the health check packet originating from another node along the ring, and a process of transmitting / receiving the health check packet to each source node The arrival / non-arrival of the health check packet originated from another node is monitored in the above. When the health check packet arrives from both rings, the ring in which the health check packet arrives first is selected as the receiving ring of the data packet originated from the other node, and one of the rings is received. When arriving from only the ring, by selecting the one ring as the receiving ring of the data packet originating from the other node, the receiving ring selecting step of obtaining the relationship of the receiving ring with respect to the source node and holding it updatable, Data addressed to another node that arrived by sending data packets to both rings And a packet transmitting / receiving step of relaying the packet along the ring and receiving or discarding the arrived data packet addressed to the own node based on the contents held in the receiving ring selection step. Ring selection method in the system. 9. A ring selection method in a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of a primary ring and a secondary ring having opposite directions. , The plurality of nodes periodically transmits a health check packet indicating the remaining time to both rings, subtracts the remaining time of the arrived health check packet from another node, and relays along the ring while arriving. The health check packet transmitting / receiving step of discarding the health check packet originated from the self node and the arrival / non-arrival of the health check packet for each source node in the process of transmitting / receiving the health check packet If packets arrive from both rings, the health check with the shorter remaining time for each sending node. The ring in which the check packet arrives is selected as the transmission ring of the data packet whose other node is the destination node, and when it arrives from only one ring, the one ring is selected as the transmission ring common to all the destination nodes. , If not arriving from both rings, select both rings as a common transmission ring to all destination nodes to determine the relationship of the transmission rings with respect to the destination nodes, and to retain the updateable transmission ring. A data packet transmitting / receiving step of transmitting to both rings based on the contents held in the transmission ring selection step, relaying the arrived data packet addressed to another node along the ring, and receiving the arrived data packet addressed to its own node; A method for selecting a ring in a dual ring network system, comprising: 10. A primary ring and a secondary ring having opposite directions.
A ring selection method in a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, wherein the plurality of nodes periodically send a health check packet to both rings. To send
A health check packet transmission / reception process of discarding the health check packet originating from the own node while relaying the health check packet originating from another node along the ring, and a process of transmitting / receiving the health check packet to each source node The arrival / non-arrival of the health check packet is monitored at each node, and when the health check packet originating from the own node arrives from both rings, the other node is the destination node of the ring after which the health check packet arrives for each transmitting node. Select it as the transmission ring for data packets,
When arriving from only one ring, select the one ring as a transmission ring common to all destination nodes,
If it does not arrive from both rings, both rings are selected as common transmission rings for all destination nodes, and the transmission ring selection step of obtaining the relationship of the transmission rings with respect to the destination nodes and holding it updatable; A data packet transmission / reception step of transmitting to both rings based on the content held in the transmission ring selection step, relaying the arrived data packet addressed to another node along the ring, and receiving the arrived data packet addressed to the own node. A method for selecting a ring in a dual ring network system characterized by the above. 11. The data packet transmitting / receiving step comprises a step of adding a serial number to data packets to be transmitted to both rings, and the data packets arriving from both rings originate from the same node and have the same number. The dual ring network system according to any one of claims 7 to 10, further comprising: a selective receiving step of receiving only a data packet arriving from one of the rings when the data packet is a destination data packet. Ring selection method in. 12. In the process of transmitting and receiving the health check packet, the arrival status of the health check packet is monitored for each source node, and when the arrival status of the health check packet changes, the data packet reception is prohibited for a certain period. A reception prohibition period setting step of setting a period; and a discarding step of discarding the data packet addressed to the own node that has arrived from both rings within the data packet reception prohibition period in the data packet transmission / reception step. A ring selection method in a dual ring network system according to any one of claims 7 to 10. 13. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of nodes periodically transmits a health check packet to both rings,
A health check packet transmission / reception means for discarding a health check packet originating from its own node while relaying a health check packet originating from another node along the ring, and for each source node in the process of transmitting / receiving the health check packet. The arrival / non-arrival of the health check packet originating from the self node is monitored, and when it arrives from both rings, it is determined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the unicast data packet to be transmitted. Select a ring as the transmit ring, select one ring as the transmit ring if it arrives from only one ring, or select both rings as the transmit ring if it does not arrive from both rings Selecting means and a unicast data packet for linking based on the selection result. Data packet transmitting / receiving means for transmitting the received unicast data packet to another node, relaying the unicast data packet to the other node along the ring, and receiving the unicast data packet to the own node. Ring network system. 14. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of nodes periodically transmits a health check packet to both rings,
A health check packet transmission / reception means for discarding a health check packet originating from its own node while relaying a health check packet originating from another node along the ring, and for each source node in the process of transmitting / receiving the health check packet. The arrival / non-arrival of the health check packet originated from its own node is monitored, and when it arrives from both rings, the bit at the predetermined bit position of the destination node group identifier that identifies the group of multiple destination nodes of the multicast data packet to be transmitted. The ring defined by the logical value of is selected as the transmission ring, and if one of the rings arrives, one of the rings is selected as the transmission ring. Transmission ring selection means for selecting a ring as the transmission ring, Data that transmits a last data packet to the ring based on the selection result, relays the arrived multicast data packet originating from another node along the ring, performs reception processing, and discards the arrived multicast data packet originating from the own node. A dual ring network system comprising: a packet transmitting / receiving means. 15. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of nodes periodically transmits a health check packet to both rings,
A health check packet transmission / reception means for discarding a health check packet originating from its own node while relaying a health check packet originating from another node along the ring, and for each source node in the process of transmitting / receiving the health check packet. The arrival / non-arrival of the health check packet is monitored at each node, and when the health check packet originated from the own node arrives from both rings, it depends on the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted. If the ring specified by the above is selected as the transmission ring, and only one ring arrives, the one ring is selected as the transmission ring, and if both rings do not arrive, both rings are the transmission rings. The transmission ring selection means to be selected and the user sent from the accommodating terminal. The cast data packet is transmitted to the ring based on the selection result, the unicast data packet arriving from another node is relayed along the ring, and the unicast data packet is sent to the terminal accommodated by the own node. A dual ring network system comprising: a data packet transmitting / receiving unit that relays to the accommodation terminal and discards the unicast data packet originating from the own node. 16. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of nodes periodically transmits a health check packet to both rings,
A health check packet transmission / reception means for discarding a health check packet originating from its own node while relaying a health check packet originating from another node along the ring, and for each source node in the process of transmitting / receiving the health check packet. The arrival / non-arrival of the health check packet is monitored at the destination node, and when the health check packet originated from the own node arrives from both rings, a predetermined destination terminal group identifier that identifies a group of multiple destination terminals of the multicast data packet to be transmitted is specified. When the ring determined according to the logical value of the bit at the bit position is selected as the transmission ring, and only one ring arrives, the one ring is selected as the transmission ring and does not arrive from both rings. Chooses both rings as the transmit ring The selecting means and the multicast data packet sent from the accommodated terminal are transmitted to the ring based on the selection result, the arrived multicast data packet from another node is relayed along the ring, and addressed to the terminal accommodated by the own node. And a data packet transmitting / receiving unit for relaying the multicast data packet to the accommodation terminal and discarding the arrived multicast data packet originating from its own node. 17. The transmission ring selecting means obtains a random bit value by performing a predetermined calculation on a part or all of the identifier when a health check packet originating from the own node arrives from both rings. The dual ring network system according to any one of claims 13 to 16, further comprising: means for selecting a ring determined according to a bit value thereof as a transmission ring. 18. A primary ring and a secondary ring having opposite directions.
A ring selection method in a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, wherein the plurality of nodes periodically send a health check packet to both rings. To send
A health check packet transmission / reception process of discarding the health check packet originating from the own node while relaying the health check packet originating from another node along the ring, and a process of transmitting / receiving the health check packet to each source node The arrival / non-arrival of the health check packet originating from the self node is monitored, and when it arrives from both rings, it is determined according to the logical value of the bit at the predetermined bit position of the destination node identifier of the unicast data packet to be transmitted. Select a ring as the transmit ring, select one ring as the transmit ring if it arrives from only one ring, or select both rings as the transmit ring if it does not arrive from both rings A selection step, and a unicast data packet is linked based on the selection result. And a data packet transmitting / receiving step of relaying a unicast data packet addressed to another node that has arrived and relayed along a ring, and receiving processing of the unicast data packet addressed to the own node. Ring selection method in network system. 19. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of node sides periodically transmit a health check packet to both rings,
A health check packet transmission / reception process of discarding the health check packet originating from the own node while relaying the health check packet originating from another node along the ring, and a process of transmitting / receiving the health check packet to each source node The arrival / non-arrival of the health check packet originated from its own node is monitored, and when it arrives from both rings, the bit at the predetermined bit position of the destination node group identifier that identifies the group of multiple destination nodes of the multicast data packet to be transmitted. The ring defined by the logical value of is selected as the transmission ring, and if one of the rings arrives, one of the rings is selected as the transmission ring. A transmission ring selection process for selecting a ring as a transmission ring, Data that transmits a last data packet to the ring based on the selection result, relays the arrived multicast data packet from another node along the ring, performs reception processing, and discards the arrived multicast data packet from the own node. A ring selecting method in a dual ring network system, comprising: a packet transmitting / receiving step. 20. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of node sides periodically transmit a health check packet to both rings,
A health check packet transmission / reception process of discarding the health check packet originating from the own node while relaying the health check packet originating from another node along the ring, and a process of transmitting / receiving the health check packet to each source node The arrival / non-arrival of the health check packet is monitored at each node, and when the health check packet originated from the own node arrives from both rings, it depends on the logical value of the bit at the predetermined bit position of the destination terminal identifier of the unicast data packet to be transmitted. If the ring specified by the above is selected as the transmission ring, and only one ring arrives, the one ring is selected as the transmission ring, and if both rings do not arrive, both rings are the transmission rings. The transmission ring selection process to be selected and the user sent from the accommodating terminal. The cast data packet is transmitted to the ring based on the selection result, the unicast data packet arriving from another node is relayed along the ring, and the unicast data packet is sent to the terminal accommodated by the own node. A ring selection method in a dual ring network system, comprising: a data packet transmission / reception step of discarding a unicast data packet originating from its own node that is relayed to an accommodation terminal. 21. A primary ring and a secondary ring having opposite directions.
In a dual ring network system in which a plurality of nodes are connected via a transmission medium or line composed of a dual ring of the next ring, the plurality of node sides periodically transmit a health check packet to both rings,
A health check packet transmission / reception process of discarding the health check packet originating from the own node while relaying the health check packet originating from another node along the ring, and a process of transmitting / receiving the health check packet to each source node The arrival / non-arrival of the health check packet is monitored at the destination node, and when the health check packet originated from the own node arrives from both rings, a predetermined destination terminal group identifier that identifies a group of multiple destination terminals of the multicast data packet to be transmitted is specified. When the ring determined according to the logical value of the bit at the bit position is selected as the transmission ring, and only one ring arrives, the one ring is selected as the transmission ring and does not arrive from both rings. Chooses both rings as the transmit ring Selection step, transmitting multicast data packets sent from the accommodating terminal to the ring based on the selection result, relaying arrived multicast data packets originating from other nodes along the ring, and addressed to the terminal accommodating by the own node And a data packet transmitting / receiving step of relaying the multicast data packet to the accommodating terminal and discarding the arrived multicast data packet originating from its own node, the method for selecting a ring in a dual ring network system. . 22. In the transmission ring selection step, when a health check packet originated from the own node arrives from both rings, a predetermined calculation is performed on a part or all of the identifier to obtain a random bit value. A ring selecting method in a dual ring network system according to any one of claims 18 to 21, further comprising: selecting a ring defined according to its bit value as a transmission ring.