WO2010095268A1 - Ring network control method, master node, slave node, and ring network - Google Patents

Ring network control method, master node, slave node, and ring network Download PDF

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Publication number
WO2010095268A1
WO2010095268A1 PCT/JP2009/053214 JP2009053214W WO2010095268A1 WO 2010095268 A1 WO2010095268 A1 WO 2010095268A1 JP 2009053214 W JP2009053214 W JP 2009053214W WO 2010095268 A1 WO2010095268 A1 WO 2010095268A1
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node
port
control frame
blocked
master node
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PCT/JP2009/053214
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French (fr)
Japanese (ja)
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美里 亀井
和海 小口
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三菱電機株式会社
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Priority to PCT/JP2009/053214 priority Critical patent/WO2010095268A1/en
Publication of WO2010095268A1 publication Critical patent/WO2010095268A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/42—Loop networks
    • H04L12/437—Ring fault isolation or reconfiguration

Definitions

  • the present invention relates to a control method in a ring network.
  • ring networks that achieve high reliability by providing communication path redundancy in the network configuration have been widely used.
  • broadcast frames continue to flow when a loop occurs, so normally a single port on the ring network is blocked to prevent the occurrence of a loop.
  • a method has been proposed in which when a failure occurs on the ring network, the failure is automatically detected and the communication path is switched without causing a loop.
  • STP Sesing Tree Protocol
  • BPDU Binary Protocol Data Unit
  • Patent Document 1 a control frame with a device identification string is bidirectionally transmitted / received between the devices constituting the ring, the failure detection and the occurrence location are specified, and the device that blocks the port when the failure is detected A technique for avoiding a loop by releasing the blockade after waiting for the blockage release command is disclosed.
  • one port of the master node on the ring network is normally closed to avoid the occurrence of a loop.
  • the node that detected the failure closes the link or the node-side port that detected the failure, and sends a control frame that notifies the release of the block to the master node.
  • the master node can switch to the normal communication path by releasing the blocked port. Even when a failure is recovered, it is possible to switch the communication path by avoiding the occurrence of a loop by closing the port of the master node and then releasing the blocked port at the time of failure.
  • Patent Document 2 when a loop has occurred, since the port transition of the address learning entry in the address learning table frequently occurs, the bridge device detects the loop by monitoring the occurrence frequency for each port, A technique for recovering from a loop state by closing a port that has detected a loop is disclosed.
  • the above-described conventional technique has a problem that when a blocked port is erroneously released due to a malfunction of the device, a state (loop) in which there is no blocked port on the ring network occurs.
  • a state (loop) in which there is no blocked port on the ring network occurs.
  • an erroneous setting that sets a plurality of blocked ports on the ring network occurs, there is a problem that the communication path is divided and normal communication cannot be maintained.
  • the present invention has been made in view of the above, and an object of the present invention is to obtain a ring network control method capable of detecting and recovering from an abnormality in a blocked port setting.
  • the present invention is configured so that a plurality of nodes having two or more ports for performing communication are connected in a ring shape, and at least one node is connected to a network state.
  • a ring network control method in a ring network in which a master node to be monitored and a slave node in accordance with an instruction from the master node are used, wherein the master node has a control frame having a block number field indicating the block port number.
  • the control frame transmission step for transmitting to the adjacent slave node, and when the slave node that received the control frame has a blocked port, rewrite the field of the number of blocked locations of the control frame, and then rewrite the control frame
  • Control frame transfer step for transferring to a node other than the source node
  • the master node checks the field of the number of blocked points in the received control frame and detects whether the blocked port setting is normal or abnormal
  • the ring network control method according to the present invention has an effect that it is possible to detect and restore an abnormality in the blocked port setting.
  • FIG. 1 is a diagram illustrating a configuration example of a ring network.
  • FIG. 2 is a diagram illustrating a ring network in which two ports are blocked.
  • FIG. 3 is a diagram illustrating a configuration example of a block number monitoring control frame.
  • FIG. 4 is a flowchart showing the block port confirmation process.
  • FIG. 5 is a diagram illustrating the transition of each field of the block number monitoring control frame.
  • FIG. 6 is a diagram illustrating the transition of each field of the block number monitoring control frame.
  • FIG. 7 is a diagram illustrating a ring network in which a loop has occurred.
  • FIG. 8 is a diagram showing the transition of each field of the block number monitoring control frame.
  • FIG. 9 is a diagram illustrating a ring network in which two ports are blocked.
  • FIG. 10 is a diagram illustrating the transition of each field of the block number monitoring control frame.
  • FIG. 11 is a diagram illustrating a recovery process after abnormality detection.
  • FIG. 12 is a diagram illustrating a ring network in which a link break has occurred.
  • FIG. 13 is a diagram illustrating the flow of the blockage number monitoring control frame.
  • FIG. 14 is a diagram illustrating transition of each field of the block number monitoring control frame.
  • FIG. 15 is a diagram illustrating a ring network that blocks a plurality of ports.
  • FIG. 16 is a diagram illustrating the transition of each field of the block number monitoring control frame.
  • FIG. 17 is a diagram illustrating a configuration example of a block number monitoring control frame.
  • FIG. 18 is a diagram illustrating a state in which the master node has failed.
  • FIG. 19 is a diagram showing transmission / reception of a control frame between the master node and the spare master node.
  • FIG. 20 is a diagram illustrating a state in
  • FIG. 1 is a diagram illustrating a configuration example of a ring network.
  • the ring network includes a master node 11, slave nodes 21 to 25, and links 41 to 46. Each node has two ports for the ring network, which are represented by ports 31 to 3C, respectively.
  • the master node 11 is a node that monitors the state of the ring network.
  • the slave nodes 21 to 25 are nodes that follow the instruction of the master node 11.
  • Ports 31 to 3C are interfaces for inputting / outputting data to / from adjacent nodes.
  • the links 41 to 46 are transmission lines that constitute a ring.
  • the master node and the slave node are arranged at the illustrated positions, but any node on the ring network may be the master node, and any node may be the slave node.
  • one port of the master node 11 is blocked (port 31 or port 3C, for example, port 31 is a blocked port), and a user frame is blocked to avoid a loop state.
  • the slave node that detects the failure closes the port, and the master node 11 releases the port 31 from being blocked.
  • the master node 11 again closes one port (port 31), and the slave node that has blocked the port releases the port blocking.
  • a loop may occur when the master node 11 releases the block of the port 31 while the port of another slave node to be blocked is not blocked due to a device (node) failure or the like.
  • the port is blocked at a plurality of locations because the master node 11 blocks the port 31 while the slave node that should release the block does not release the port when the failure is recovered.
  • the master node 11 confirms that the blocked port in the ring network has been canceled by mistake (blocked port erroneous release) and that multiple blocked ports have been set (blocked port error).
  • a monitoring control frame (blocking location number monitoring control frame) having a field indicating the number of blocking locations (blocking location number field) is transmitted from the ports 31 and 3C on both sides to block on the ring network. Monitor the number of locations.
  • Ethernet In Ethernet (registered trademark), in order to send and receive the block location monitoring control frame, a control VLAN (Virtual Local Area Network) that makes one round of the ring from the master node 11 is set, and the block location monitoring control frame is set. May use a VSM (Vendor Specific Message) frame, which is a type of Ethernet (registered trademark) OAM (Operations, Administration, Maintenance) frame.
  • VSM Vehicle Specific Message
  • FIG. 2 is a diagram illustrating a state in which two ports at both ends of the link are blocked in the ring network.
  • the master node 11 In the ring network, it is possible for the master node 11 to secure a normal communication path (link 42 ⁇ link 41 ⁇ link 46 ⁇ link 45 ⁇ link 44) by releasing the blocking of the port 31.
  • the state in FIG. 2 is not an abnormality in the number of blocked locations (incorrect setting of a blocked port, erroneous release of a blocked port). In such a case, since the number of blocked locations is not set to “2”, a field (set flag field) for distinguishing the state of FIG. 2 from erroneous setting of the blocked ports is provided in the blocked location number monitoring control frame.
  • FIG. 3 is a diagram illustrating a configuration example of a block number monitoring control frame.
  • the block number monitoring control frame is a control frame having a destination address, a transmission source address, a block number field, and a set flag field.
  • the transmission source address is the address of the master node 11.
  • the port 31 is transmitted in the clockwise direction (the direction of the link 41) and the port 3C is transmitted in the counterclockwise direction (the direction of the link 46).
  • the block number monitoring control frame is transmitted to only one of them. Even in this case, an abnormality in the blocked port setting can be detected by making one round of the ring network. However, in consideration of the case where a one-way communication failure occurs, it is desirable to transmit in both directions.
  • the master node 11 and the slave nodes 21 to 25 define a field indicating that the received frame is a blocked part number monitoring control frame in the frame so that the received frame is recognized as a blocked part number monitoring control frame. Also good.
  • FIG. 4 is a flowchart showing the block port confirmation process in the slave node.
  • the slave node 25 When the slave node 25 receives the block number monitoring control frame (step S1), it confirms whether or not the reception port (port 3B) constituting the ring is blocked (step S2). When the reception port is blocked (step S2: Yes), the set flag field of the block number monitoring control frame is confirmed (step S3). When the set flag field is “0” (step S3: Yes), 1 is added to the value of the blockage number field (+1) (step S4), and the set flag field is set to “0” (step S5). When the reception port is not blocked (step S2: No) and when the set flag field is not “0” (step S3: No), the set flag field is set to “0” (step S5).
  • the slave node 25 checks whether or not the transmission port (port 3A) constituting the ring is blocked (step S6).
  • the transmission port is blocked (step S6: Yes)
  • 1 is added to the value of the block number field (+1) (step S7)
  • the set flag field is set to “1” (step S8).
  • the slave node 25 transmits a block location monitoring control frame in which the values of the block location number field and the set flag field are rewritten to the adjacent slave node 24 (step S9).
  • the slave node 25 transmits a block number monitoring control frame to the adjacent slave node 24 (step S9).
  • the slave node 24 that has received the block number monitoring control frame performs the processing of steps S1 to S9 and relays the block number monitoring control frame. In this case, the slave node 24 transfers to the adjacent slave node 23. Similarly, transfer of the blockage number monitoring control frame transmitted from the port 31 to the slave node 21 by the master node 11 is repeated between the slave nodes.
  • the master node 11 receives the block number monitoring control frame and confirms the block number field of the block number monitoring control frame.
  • the number of blocked locations field is “2 or more”
  • the master node 11 detects an abnormality in the blocked port setting as an erroneous setting of the blocked port.
  • the block location number field is “0” and the transmission source address is the address of the own device (master node 11)
  • a block port setting error is detected as an erroneous release of the block port.
  • the master node 11 discards the block number monitoring control frame after confirming the block number field.
  • FIG. 5 shows the transition of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11.
  • FIG. 5 is a diagram showing the transition of each field of the block number monitoring control frame in each node.
  • This is a diagram showing the transition of the block number field and the set flag field when the block number monitoring control frame passes through each node.
  • the master node 11 recognizes that the blocked port setting is normal because the number of blocked locations field is “1” when returning around the ring network. Actually, only the port 31 of the master node 11 is blocked, and a normal communication path can be secured in the entire ring network.
  • FIG. 6 shows the transition of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11 in the ring network of FIG.
  • FIG. 6 is a diagram illustrating the transition of each field of the block number monitoring control frame in each node.
  • the port 36 and the port 35 are blocked, but the blocked port of the port 35 is not counted by using the set flag field (step S3: No process in the flowchart of FIG. 4). Therefore, the master node 11 recognizes that the blocked port setting is normal because the number of blocked locations field is “1” when returning around the ring network.
  • the number of blocked ports is two, but the number of blocked ports is one, and a normal communication path can be secured in the entire ring network.
  • FIG. 8 shows transitions of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11.
  • FIG. 7 is a diagram illustrating a ring network in which a loop has occurred.
  • FIG. 8 is a diagram showing transition of each field of the blockage number monitoring control frame in each node.
  • the master node 11 is able to detect erroneous release of the blocked port because the number of blocked locations field is “0” when returning around the ring network. Actually, a loop occurs and a broadcast frame continues to flow and normal communication cannot be performed.
  • FIG. 10 shows the transition of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11 in the ring network of FIG.
  • FIG. 9 is a diagram illustrating a ring network in which two ports are blocked.
  • FIG. 10 is a diagram showing transition of each field of the blockage number monitoring control frame in each node.
  • the master node 11 is able to detect erroneous release of the blocked port because the number of blocked locations field is “2” when returning around the ring network.
  • the route is divided due to blockage at a plurality of locations, and a route between nodes that cannot communicate user data is generated.
  • FIG. 11 is a diagram illustrating a recovery process after abnormality detection.
  • the master node 11 blocks one port (for example, the port 31) of the master node.
  • the master node 11 transmits a blocking release instruction control frame for instructing the release of the blocking port to the slave nodes 21 and 25. Since it is confirmed that the block number monitoring control frame has made one round of the ring network, transmission in one direction may be performed, but transmission in both directions is desirable.
  • the slave nodes 21 and 25 When the slave nodes 21 and 25 receive the blocking release instruction control frame, the slave nodes 21 and 25 transfer the blocking release instruction control frame to the nodes (slave nodes 22 and 24) adjacent to the direction opposite to the direction in which the slave release instruction control frame is received, and the ports blocked by the own device. If there is, release the block. In FIG. 11, the slave node 25 releases the blocking of the port 3A.
  • the slave nodes 22 and 24 that have received the block release instruction control frame receive the above 3.
  • the same process is performed. In FIG. 11, in this process, the slave node 22 releases the block of the port 34. Thereafter, each slave node that has received the block release instruction control frame receives the above 3. By repeating this process, the blockage release instruction control frame goes around the ring network and returns to the master node 11. The master node 11 discards the received block release instruction control frame.
  • the slave nodes 21 to 25 are not blocked. In the ring network, only the master node 11 blocks one port (port 31).
  • the slave node 11 can detect an abnormality in the blocked port setting using the block number monitoring control frame, and can recover the abnormality detected using the block release instruction control frame. did. As a result, a communication failure can be quickly recovered and a normal communication path can be secured, so that the reliability of the ring network can be improved.
  • Embodiment 2 the communication path is secured even in one direction, and the master node 11 detects an abnormality in the blocked port setting when the transmitted block number monitoring control frame returns around the link network. it can. However, if the block location monitoring control frame does not return, the master node 11 can detect that there is some failure on the ring network, but cannot detect an abnormal block port setting.
  • a method for detecting an abnormality in the blocked port setting even when a failure has occurred on the ring network will be described.
  • FIG. 12 is a diagram showing a ring network in which a link break has occurred in the link 43.
  • the master node 11 can detect a failure such as a link disconnection by not returning the transmitted blockage number monitoring control frame.
  • the slave nodes 22 and 23 connected to the link 43 can detect that a failure has occurred in the link 43.
  • the slave nodes 22 and 23 that have detected the failure block the ports (ports 35 and 36) that have suffered the failure.
  • the slave nodes 22 and 23 that have detected the failure transmit the block number monitoring control frame with the block number field set to “1” from the normal port (ports 34 and 37).
  • the transmission source address of the block number monitoring control frame is the address of the own node (slave node 22 or 23).
  • the master node 11 When the master node 11 receives the block number monitoring control frame, if the transmission source address is not its own node (master node 11) and the block number field is “2 or more”, the blocked port setting error Can be detected. The received block number monitoring control frame is discarded as in the first embodiment.
  • FIG. 13 is a diagram showing the flow of the blockage number monitoring control frame. The correspondence of the above processing ((1) to (4)) in each node is shown.
  • FIG. 14 shows the transition of the block number field and the set flag field of the block number monitoring control frame transmitted in the clockwise direction by the slave node 23 detecting the failure in the ring network of FIG.
  • FIG. 14 is a diagram illustrating the transition of each field of the block number monitoring control frame in each node. In this case, the master node 11 recognizes that the blocked port setting is normal because the blocked location number field is “1”.
  • FIG. 15 is a diagram illustrating a state where a plurality of ports are blocked in the ring network.
  • FIG. 16 is a diagram showing transition of each field of the blockage number monitoring control frame in each node.
  • the master node 11 can detect an abnormality in the blocked port setting (incorrect setting of the blocked port) because the number of blocked locations field is “2”.
  • the nodes on both sides (for example, the slave nodes 22 and 23 in FIG. It is desirable to periodically transmit the blockage number monitoring control frame.
  • the master node 11 has not received the block location monitoring control frame transmitted by its own node (master node 11), or has received a block location monitoring control frame whose source address is not its own node (master node 11). Thus, it is possible to detect that there is some failure on the ring network.
  • FIG. 17 is a diagram illustrating a configuration example of a block number monitoring control frame. A field that is blocked due to a failure has been added. The slave node that has detected the failure sets “1” to “blocking” due to the occurrence of the failure at the time of transmission, and the slave node that relays does not change the value.
  • the master node 11 sees the blockage due to failure occurrence and the blockage location number field in the received blockage number monitoring control frame received, the blockage due to failure occurrence is “1”, and the blockage location number field is “2 or more. ", It is possible to detect an abnormality in the blocked port setting during the occurrence of a failure.
  • the master node 11 that has detected an abnormality in the blocked port setting during the occurrence of a failure does not detect a failure in its own node but blocks the port (for example, the port 31 is blocked). If so, the port 31 is unblocked).
  • the master node 11 transmits the blocking release instruction control frame in both directions of the slave node 21 (clockwise) and the slave node 25 (counterclockwise).
  • the slave nodes 21 and 25 When the slave nodes 21 and 25 receive the block release instruction control frame, the slave nodes 21 and 25 transfer the block to the node adjacent to the direction opposite to the received direction, and release the block if there is a port blocked by the own device.
  • the nodes on both sides (for example, slave nodes 22 and 23) that detected the failure do not release the block of the ports (ports 35 and 36) that detected the failure, but discard the block release instruction control frame.
  • the master node does not need to be specified as one on the ring network, and a sub-master node that performs the same processing as the master node may be set.
  • all nodes can perform the same process as the master node, and all nodes can detect a blocked port setting error.
  • Embodiment 3 In the first and second embodiments, only one master node is set on the ring network, the master node is not broken, and it is possible to detect transmission / reception of control frames and abnormalities in blocked port settings. It is a premise. However, when only one master node is set on the ring network, if the master node fails and the links on both sides of the master node are disconnected and communication is not possible, an abnormality in the blocked port setting on the ring network cannot be detected. . In this embodiment, a case where a spare master node is set will be described.
  • FIG. 18 is a diagram showing a state in which the master node 11 has failed in the ring network. In such a case, the links on both sides of the master node 11 are disconnected, making communication impossible, and it is impossible to detect an abnormality in the blocked port setting on the ring network.
  • At least one of the slave nodes is set as a spare master node (slave node 23 as an example), and the block number monitoring control frame It is possible to detect errors in transmission and blocked port settings.
  • a spare master node for example, control frames are periodically transmitted and received between the spare master node (slave node 23) and the master node 11.
  • the spare master node (slave node 23) monitors the normality of the master node 11 by a method such as assuming that the master node 11 has failed when the control frame from the master node 11 does not reach.
  • FIG. 19 is a diagram illustrating transmission and reception of control frames between the master node 11 and a spare master node (slave node 23).
  • FIG. 20 is a diagram illustrating a state in which a spare master node (slave node 23) is operating as a master node. Only when the master node 11 is out of order, the spare master node (slave node 23) is the master node and performs the processing described in the first and second embodiments.
  • the Ethernet may use a CC (Continuity Check) function that is a function of the Ethernet (registered trademark) OAM.
  • any node may transmit the blocked point number monitoring control frame. For example, when a plurality of spare master notes are set, all the spare master nodes are transmitted. Even when operating as a master node, each node can detect an abnormality by checking whether there is an abnormality in the blocked port setting if the transmission source address is the address of its own device. However, it is necessary to recover from a blocked port setting abnormality, and in the second embodiment, only one node on the ring network needs to terminate the control frame as a master node and block at the time of recovery. Therefore, when multiple spare master nodes are set, priorities are assigned to the spare master nodes, and a master node with a lower priority is assigned to the master node only when all other master nodes with higher priorities have failed. Works.
  • the present embodiment it is possible to detect a blocked port setting error and recover the detected error even when the master node fails. As a result, a communication failure can be quickly recovered and a normal communication path can be secured, so that the reliability of the ring network can be improved.
  • the ring network control method according to the present invention is useful for a ring network that achieves high reliability, and is particularly suitable as a ring network that enables detection and recovery of an abnormality in a blocked port setting.

Abstract

Provided is a ring network control method which includes: a control frame transmission step in which a master node transmits a control frame; a control frame transfer step in which a slave node rewrites a closed portion quantity field of the control frame if any closed port exists and then transfers the control frame; a detection step in which the master node checks the closed portion quality field if the control frame is returned to the master node so as to detect whether the closed port setting is normal; a port close step in which the master node closes at least one port if a failure of the closed port setting is detected and the master node has not closed the port; a close release transmission step in which the master node transmits the close release control frame; and a close release transfer step in which the slave node release a closed port if any in the slave node and transfers the close release control frame.

Description

リングネットワーク制御方法、マスタノード、スレーブノードおよびリングネットワークRing network control method, master node, slave node, and ring network
　本発明は、リングネットワークにおける制御方法に関する。 The present invention relates to a control method in a ring network.
　従来、ネットワーク構成に通信路の冗長性を持たせて高信頼化を実現するリングネットワークが広く採用されている。リングネットワークでは、ループが発生するとブロードキャストフレームが流れ続けるため、通常時はリングネットワーク上の単一のポートを閉塞してループの発生を防ぐ。また、リングネットワーク上で障害が発生した際、障害を自動的に検出し、ループを発生させることなく通信経路を切り替える手法が提案されている。 Conventionally, ring networks that achieve high reliability by providing communication path redundancy in the network configuration have been widely used. In a ring network, broadcast frames continue to flow when a loop occurs, so normally a single port on the ring network is blocked to prevent the occurrence of a loop. Also, a method has been proposed in which when a failure occurs on the ring network, the failure is automatically detected and the communication path is switched without causing a loop.
　非特許文献１に記載のＳＴＰ（Spanning　Tree　Protocol）では、ＢＰＤＵ（Bridge　Protocol　Data　Unit）の制御フレームを用いてリングネットワークの状態を監視し、ループ状態を防ぐとともに、ＢＰＤＵが一定時間届かなかった場合に障害の発生を検出する。ＳＴＰでは、障害箇所でループが解除されるとして障害箇所のポートを閉塞せずに通常時の閉塞ポートを解除するため、実際には障害が発生していないにも関わらず通常時の閉塞ポートを解除することでループが発生する場合があった。そこで、特許文献１において、リングを構成する各装置間で装置識別列を付与した制御フレームを双方向に送受信し、障害の検知と発生箇所を特定するとともに、障害検出時にポートを閉塞した装置からの閉塞解除命令を待って閉塞解除を行うことでループを回避する技術が開示されている。 In STP (Spanning Tree Protocol) described in Non-Patent Document 1, the status of the ring network is monitored using a BPDU (Bridge Protocol Data Unit) control frame to prevent a loop condition and the BPDU does not arrive for a certain period of time. The occurrence of a failure is detected. In STP, since the loop is released at the fault location, the normal block port is released without blocking the fault port. Therefore, the normal block port is not used even though no fault has actually occurred. There was a case where a loop occurred by releasing. Therefore, in Patent Document 1, a control frame with a device identification string is bidirectionally transmitted / received between the devices constituting the ring, the failure detection and the occurrence location are specified, and the device that blocks the port when the failure is detected A technique for avoiding a loop by releasing the blockade after waiting for the blockage release command is disclosed.
　非特許文献２では、通常時はリングネットワーク上のマスタノードの片方のポートを閉塞し、ループの発生を回避している。障害発生時、障害を検出したノードが、障害を検出したリンクまたはノード側のポートを閉塞し、閉塞解除を通知する制御フレームをマスタノードへ送信する。マスタノードが閉塞ポートを解除することで、正常な通信路への切り替えが可能である。障害復旧時も、マスタノードのポートを閉塞してから、障害時の閉塞ポートを解除することで、ループの発生を回避した通信路の切り替えが可能である。 In Non-Patent Document 2, one port of the master node on the ring network is normally closed to avoid the occurrence of a loop. When a failure occurs, the node that detected the failure closes the link or the node-side port that detected the failure, and sends a control frame that notifies the release of the block to the master node. The master node can switch to the normal communication path by releasing the blocked port. Even when a failure is recovered, it is possible to switch the communication path by avoiding the occurrence of a loop by closing the port of the master node and then releasing the blocked port at the time of failure.
　また、特許文献２において、ループが発生している場合、アドレス学習テーブルにおけるアドレス学習エントリのポート遷移が多発するため、ブリッジ装置が、発生頻度をポート毎に監視することでループの検出を行い、ループを検出したポートを閉塞することでループ状態から復旧する技術が開示されている。 Further, in Patent Document 2, when a loop has occurred, since the port transition of the address learning entry in the address learning table frequently occurs, the bridge device detects the loop by monitoring the occurrence frequency for each port, A technique for recovering from a loop state by closing a port that has detected a loop is disclosed.
特開２００７－０１９６９８号公報JP 2007-019698 A 特開２００５－０３３３６０号公報JP 2005-033360 A
　しかしながら、上記従来の技術では、装置の誤動作などにより閉塞ポートが誤解除されてしまった場合には、リングネットワーク上に閉塞ポートが１つもない状態（ループ）が発生する、という問題があった。また、閉塞ポートをリングネットワーク上に複数箇所設定してしまう誤設定が発生した場合には、通信経路が分断されて正常な通信が保てない、という問題があった。 However, the above-described conventional technique has a problem that when a blocked port is erroneously released due to a malfunction of the device, a state (loop) in which there is no blocked port on the ring network occurs. In addition, when an erroneous setting that sets a plurality of blocked ports on the ring network occurs, there is a problem that the communication path is divided and normal communication cannot be maintained.
　本発明は、上記に鑑みてなされたものであって、閉塞ポート設定の異常を検出し、復旧することが可能なリングネットワーク制御方法を得ることを目的とする。 The present invention has been made in view of the above, and an object of the present invention is to obtain a ring network control method capable of detecting and recovering from an abnormality in a blocked port setting.
　上述した課題を解決し、目的を達成するために、本発明は、通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおけるリングネットワーク制御方法であって、前記マスタノードが、閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを、隣接するスレーブノードに送信する制御フレーム送信ステップと、制御フレームを受信したスレーブノードが、閉塞ポートがある場合に当該制御フレームの閉塞箇所数のフィールドを書き換え、その後、書き換え後の制御フレームを、送信元ノード以外のノードに転送する制御フレーム転送ステップと、制御フレームがリングネットワークを一周して前記マスタノードに戻ってきた場合、当該マスタノードが、受信した制御フレームの閉塞箇所数のフィールドを確認し、閉塞ポート設定の正常または異常を検出する検出ステップと、閉塞ポート設定の異常が検出された場合に、前記マスタノードが、自装置のポートを閉塞していないときは少なくとも１つのポートを閉塞するポート閉塞ステップと、前記マスタノードが、スレーブノードに向けて、閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを送信する閉塞解除送信ステップと、閉塞解除制御フレームを受信したスレーブノードが、自装置に閉塞ポートがある場合にそのポートの閉塞を解除し、また、当該閉塞解除制御フレームを、送信元ノード以外のノードに転送する閉塞解除転送ステップと、を含むことを特徴とする。 In order to solve the above-described problems and achieve the object, the present invention is configured so that a plurality of nodes having two or more ports for performing communication are connected in a ring shape, and at least one node is connected to a network state. A ring network control method in a ring network in which a master node to be monitored and a slave node in accordance with an instruction from the master node are used, wherein the master node has a control frame having a block number field indicating the block port number. The control frame transmission step for transmitting to the adjacent slave node, and when the slave node that received the control frame has a blocked port, rewrite the field of the number of blocked locations of the control frame, and then rewrite the control frame, Control frame transfer step for transferring to a node other than the source node When the control frame goes around the ring network and returns to the master node, the master node checks the field of the number of blocked points in the received control frame and detects whether the blocked port setting is normal or abnormal A block blocking step of blocking at least one port when the master node does not block a port of its own device when an abnormality of the blocked port setting is detected, and the master node is a slave node If the slave node that received the block release control frame sends a block release control frame for instructing to release the block of the blocked port, and the slave node that received the block release control frame has a blocked port, Releases the blocking, and forwards the blocking release control frame to a node other than the transmission source node. And unblocking transfer step, characterized in that it comprises a.
　本発明にかかるリングネットワーク制御方法は、閉塞ポート設定の異常を検出し復旧することができる、という効果を奏する。 The ring network control method according to the present invention has an effect that it is possible to detect and restore an abnormality in the blocked port setting.
図１は、リングネットワークの構成例を示す図である。FIG. 1 is a diagram illustrating a configuration example of a ring network. 図２は、２つのポートを閉塞したリングネットワークを示す図である。FIG. 2 is a diagram illustrating a ring network in which two ports are blocked. 図３は、閉塞箇所数監視制御フレームの構成例を示す図である。FIG. 3 is a diagram illustrating a configuration example of a block number monitoring control frame. 図４は、閉塞ポートの確認処理を示すフローチャートである。FIG. 4 is a flowchart showing the block port confirmation process. 図５は、閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。FIG. 5 is a diagram illustrating the transition of each field of the block number monitoring control frame. 図６は、閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。FIG. 6 is a diagram illustrating the transition of each field of the block number monitoring control frame. 図７は、ループが発生しているリングネットワークを示す図である。FIG. 7 is a diagram illustrating a ring network in which a loop has occurred. 図８は、閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。FIG. 8 is a diagram showing the transition of each field of the block number monitoring control frame. 図９は、２つのポートを閉塞したリングネットワークを示す図である。FIG. 9 is a diagram illustrating a ring network in which two ports are blocked. 図１０は、閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。FIG. 10 is a diagram illustrating the transition of each field of the block number monitoring control frame. 図１１は、異常検出後の復旧処理を示す図である。FIG. 11 is a diagram illustrating a recovery process after abnormality detection. 図１２は、リンク断が発生しているリングネットワークを示す図である。FIG. 12 is a diagram illustrating a ring network in which a link break has occurred. 図１３は、閉塞箇所数監視制御フレームの流れを示す図である。FIG. 13 is a diagram illustrating the flow of the blockage number monitoring control frame. 図１４は、閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。FIG. 14 is a diagram illustrating transition of each field of the block number monitoring control frame. 図１５は、複数のポートを閉塞しているリングネットワークを示す図である。FIG. 15 is a diagram illustrating a ring network that blocks a plurality of ports. 図１６は、閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。FIG. 16 is a diagram illustrating the transition of each field of the block number monitoring control frame. 図１７は、閉塞箇所数監視制御フレームの構成例を示す図である。FIG. 17 is a diagram illustrating a configuration example of a block number monitoring control frame. 図１８は、マスタノードが故障した状態を示す図である。FIG. 18 is a diagram illustrating a state in which the master node has failed. 図１９は、マスタノードと予備のマスタノード間での制御フレームの送受を示す図である。FIG. 19 is a diagram showing transmission / reception of a control frame between the master node and the spare master node. 図２０は、予備のマスタノードがマスタノードとして動作している状態を示す図である。FIG. 20 is a diagram illustrating a state in which a spare master node is operating as a master node.
符号の説明Explanation of symbols
　１１　マスタノード
　２１，２２，２３，２４，２５　スレーブノード
　３１，３２，３３，３４，３５，３６，３７，３８，３９，３Ａ，３Ｂ，３Ｃ　ポート
　４１，４２，４３，４４，４５，４６　リンク 11 Master node 21, 22, 23, 24, 25 Slave node 31, 32, 33, 34, 35, 36, 37, 38, 39, 3A, 3B, 3C Port 41, 42, 43, 44, 45, 46 Link
　以下に、本発明にかかるリングネットワーク制御方法の実施の形態を図面に基づいて詳細に説明する。なお、この実施の形態によりこの発明が限定されるものではない。 Hereinafter, an embodiment of a ring network control method according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.
実施の形態１．
　図１は、リングネットワークの構成例を示す図である。リングネットワークは、マスタノード１１と、スレーブノード２１～２５と、リンク４１～４６と、から構成される。各ノードはリングネットワーク用のポートを２つ備えており、それぞれポート３１～３Ｃで表す。マスタノード１１は、リングネットワークの状態を監視するノードである。スレーブノード２１～２５は、マスタノード１１の指示に従うノードである。ポート３１～３Ｃは、隣接ノードとデータの入出力を行うインタフェースである。リンク４１～４６は、リングを構成する伝送路である。なお、図１では、マスタノードとスレーブノードを図示した位置に配置しているが、リングネットワーク上のどのノードをマスタノードとしても良く、どのノードをスレーブノードとしても良い。 Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a ring network. The ring network includes a master node 11, slave nodes 21 to 25, and links 41 to 46. Each node has two ports for the ring network, which are represented by ports 31 to 3C, respectively. The master node 11 is a node that monitors the state of the ring network. The slave nodes 21 to 25 are nodes that follow the instruction of the master node 11. Ports 31 to 3C are interfaces for inputting / outputting data to / from adjacent nodes. The links 41 to 46 are transmission lines that constitute a ring. In FIG. 1, the master node and the slave node are arranged at the illustrated positions, but any node on the ring network may be the master node, and any node may be the slave node.
　リングネットワークでは、通常時、マスタノード１１の片方のポートを閉塞し（ポート３１またはポート３Ｃ、一例としてポート３１を閉塞ポートとする）、ユーザフレームをブロックすることでループ状態を回避している。障害が発生した場合、障害を検出したスレーブノードがポートを閉塞し、マスタノード１１がポート３１の閉塞を解除する。障害が回復した場合、マスタノード１１が再度片方のポート（ポート３１）を閉塞し、ポートを閉塞していたスレーブノードがポートの閉塞を解除する。 In a ring network, normally, one port of the master node 11 is blocked (port 31 or port 3C, for example, port 31 is a blocked port), and a user frame is blocked to avoid a loop state. When a failure occurs, the slave node that detects the failure closes the port, and the master node 11 releases the port 31 from being blocked. When the failure is recovered, the master node 11 again closes one port (port 31), and the slave node that has blocked the port releases the port blocking.
　しかし、装置（ノード）の故障等により、閉塞されるべき他のスレーブノードのポートが閉塞されないまま、マスタノード１１がポート３１の閉塞を解除してしまうことで、ループが発生する場合がある。また、障害回復時等に閉塞を解除すべきスレーブノードがポートを閉塞解除しないまま、マスタノード１１がポート３１を閉塞してしまうことで、ポートが複数箇所で閉塞されてしまう場合がある。 However, a loop may occur when the master node 11 releases the block of the port 31 while the port of another slave node to be blocked is not blocked due to a device (node) failure or the like. In addition, there is a case where the port is blocked at a plurality of locations because the master node 11 blocks the port 31 while the slave node that should release the block does not release the port when the failure is recovered.
　本実施の形態では、マスタノード１１は、リングネットワーク内の閉塞ポートが誤って解除されていること（閉塞ポートの誤解除）、および、閉塞ポートが複数箇所設定されていること（閉塞ポートの誤設定）を検出するため、両側のポート３１，３Ｃから、閉塞箇所数を示すフィールド（閉塞箇所数フィールド）を持った監視制御フレーム（閉塞箇所数監視制御フレーム）を送信してリングネットワーク上の閉塞箇所の数を監視する。早期に閉塞ポート設定の異常を検出するためには、閉塞箇所数監視制御フレームを周期的に送信することが望ましい。 In the present embodiment, the master node 11 confirms that the blocked port in the ring network has been canceled by mistake (blocked port erroneous release) and that multiple blocked ports have been set (blocked port error). In order to detect (setting), a monitoring control frame (blocking location number monitoring control frame) having a field indicating the number of blocking locations (blocking location number field) is transmitted from the ports 31 and 3C on both sides to block on the ring network. Monitor the number of locations. In order to detect an abnormality in the blocked port setting at an early stage, it is desirable to periodically transmit the block number monitoring control frame.
　なお、イーサネット（登録商標）においては、閉塞箇所数監視制御フレームを送受信するため、マスタノード１１からリングを１周する制御ＶＬＡＮ（Virtual　Local　Area　Network）を設定しておき、閉塞箇所数監視制御フレームはイーサネット（登録商標）ＯＡＭ（Operations，Administration，Maintenance）フレームの一種別であるＶＳＭ（Vendor　Specific　Message）フレームを用いても良い。 In Ethernet (registered trademark), in order to send and receive the block location monitoring control frame, a control VLAN (Virtual Local Area Network) that makes one round of the ring from the master node 11 is set, and the block location monitoring control frame is set. May use a VSM (Vendor Specific Message) frame, which is a type of Ethernet (registered trademark) OAM (Operations, Administration, Maintenance) frame.
　ここで、図２のように、何らかの理由により（例えば、リンク４３を片方向のリンク断のために使用不可とする場合）リンク４３の両端のポート３５，３６を閉塞した場合を考える。図２は、リングネットワークにおいてリンクの両端の２つのポートを閉塞している状態を示す図である。リングネットワークでは、マスタノード１１がポート３１の閉塞を解除することで、正常な通信路（リンク４２→リンク４１→リンク４６→リンク４５→リンク４４）を確保することが可能である。図２の状態は、閉塞箇所数の異常（閉塞ポートの誤設定、閉塞ポートの誤解除）ではない。このような場合に閉塞箇所数を「２」としないため、閉塞箇所数監視制御フレームに、図２の状態を閉塞ポートの誤設定と区別するためのフィールド（セットフラグフィールド）を設ける。 Here, as shown in FIG. 2, consider a case where the ports 35 and 36 at both ends of the link 43 are blocked for some reason (for example, when the link 43 is disabled due to a one-way link break). FIG. 2 is a diagram illustrating a state in which two ports at both ends of the link are blocked in the ring network. In the ring network, it is possible for the master node 11 to secure a normal communication path (link 42 → link 41 → link 46 → link 45 → link 44) by releasing the blocking of the port 31. The state in FIG. 2 is not an abnormality in the number of blocked locations (incorrect setting of a blocked port, erroneous release of a blocked port). In such a case, since the number of blocked locations is not set to “2”, a field (set flag field) for distinguishing the state of FIG. 2 from erroneous setting of the blocked ports is provided in the blocked location number monitoring control frame.
　つづいて、リングネットワークにおいて、閉塞ポート設定の異常を検出する動作について説明する。 Next, the operation for detecting an abnormality in the blocked port setting in the ring network will be described.
　（１）まず、マスタノード１１が、閉塞箇所数フィールドとセットフラグフィールドを「０」にセットした閉塞箇所数監視制御フレームを、ポート３１，３Ｃからリンク４１，４６に向けて送信する。図３は、閉塞箇所数監視制御フレームの構成例を示す図である。閉塞箇所数監視制御フレームは、宛先アドレス、送信元アドレス、閉塞箇所数フィールド、セットフラグフィールド、を持つ制御フレームである。例えば、送信元アドレスは、マスタノード１１のアドレスとなる。ここでは、ポート３１から時計周り（リンク４１の方向）と、ポート３Ｃから反時計周り（リンク４６の方向）の双方向に送信するが、閉塞箇所数監視制御フレームはどちらか一方のみに送信する場合でも、リングネットワークを１周すれば閉塞ポート設定の異常を検出できる。ただし、片方向の通信障害が発生している場合を考慮し、双方向に送信することが望ましい。 (1) First, the master node 11 transmits a block location monitoring control frame in which the block location number field and the set flag field are set to “0” from the ports 31 and 3C to the links 41 and 46. FIG. 3 is a diagram illustrating a configuration example of a block number monitoring control frame. The block number monitoring control frame is a control frame having a destination address, a transmission source address, a block number field, and a set flag field. For example, the transmission source address is the address of the master node 11. Here, the port 31 is transmitted in the clockwise direction (the direction of the link 41) and the port 3C is transmitted in the counterclockwise direction (the direction of the link 46). However, the block number monitoring control frame is transmitted to only one of them. Even in this case, an abnormality in the blocked port setting can be detected by making one round of the ring network. However, in consideration of the case where a one-way communication failure occurs, it is desirable to transmit in both directions.
　なお、マスタノード１１やスレーブノード２１～２５において、受信したフレームが閉塞箇所数監視制御フレームであると認識するように、フレーム内に閉塞箇所数監視制御フレームであることを示すフィールドを定義しても良い。 The master node 11 and the slave nodes 21 to 25 define a field indicating that the received frame is a blocked part number monitoring control frame in the frame so that the received frame is recognized as a blocked part number monitoring control frame. Also good.
　（２）つぎに、閉塞箇所数監視制御フレームを受信したスレーブノードの動作について説明する。図４は、スレーブノードにおける閉塞ポートの確認処理を示すフローチャートである。一例として、スレーブノード２５について説明する。スレーブノード２５は、閉塞箇所数監視制御フレームを受信すると（ステップＳ１）、リングを構成している受信ポート（ポート３Ｂ）が閉塞しているかどうかを確認する（ステップＳ２）。受信ポートが閉塞している場合（ステップＳ２：Ｙｅｓ）、閉塞箇所数監視制御フレームのセットフラグフィールドを確認する（ステップＳ３）。セットフラグフィールドが「０」の場合（ステップＳ３：Ｙｅｓ）、閉塞箇所数フィールドの値に１を加算（＋１）して（ステップＳ４）、セットフラグフィールドを「０」にする（ステップＳ５)。受信ポートが閉塞していない場合（ステップＳ２：Ｎｏ）、およびセットフラグフィールドが「０」でない場合（ステップＳ３：Ｎｏ）、セットフラグフィールドを「０」にする（ステップＳ５)。 (2) Next, the operation of the slave node that has received the block number monitoring control frame will be described. FIG. 4 is a flowchart showing the block port confirmation process in the slave node. As an example, the slave node 25 will be described. When the slave node 25 receives the block number monitoring control frame (step S1), it confirms whether or not the reception port (port 3B) constituting the ring is blocked (step S2). When the reception port is blocked (step S2: Yes), the set flag field of the block number monitoring control frame is confirmed (step S3). When the set flag field is “0” (step S3: Yes), 1 is added to the value of the blockage number field (+1) (step S4), and the set flag field is set to “0” (step S5). When the reception port is not blocked (step S2: No) and when the set flag field is not “0” (step S3: No), the set flag field is set to “0” (step S5).
　つぎに、スレーブノード２５は、リングを構成している送信ポート（ポート３Ａ）が閉塞しているかどうかを確認する（ステップＳ６）。送信ポートが閉塞している場合（ステップＳ６：Ｙｅｓ）、閉塞箇所数フィールドの値に１を加算（＋１）して（ステップＳ７）、セットフラグフィールドを「１」にする（ステップＳ８）。その後、スレーブノード２５は、閉塞箇所数フィールドおよびセットフラグフィールドの値を書き換えた閉塞箇所数監視制御フレームを、隣接するスレーブノード２４へ送信する（ステップＳ９）。送信ポートが閉塞していない場合（ステップＳ６：Ｎｏ）、スレーブノード２５は、閉塞箇所数監視制御フレームを、隣接するスレーブノード２４へ送信する（ステップＳ９）。 Next, the slave node 25 checks whether or not the transmission port (port 3A) constituting the ring is blocked (step S6). When the transmission port is blocked (step S6: Yes), 1 is added to the value of the block number field (+1) (step S7), and the set flag field is set to “1” (step S8). Thereafter, the slave node 25 transmits a block location monitoring control frame in which the values of the block location number field and the set flag field are rewritten to the adjacent slave node 24 (step S9). When the transmission port is not blocked (step S6: No), the slave node 25 transmits a block number monitoring control frame to the adjacent slave node 24 (step S9).
　閉塞箇所数監視制御フレームを受信したスレーブノード２４は、上記ステップＳ１～Ｓ９までの処理を行い、閉塞箇所数監視制御フレームを中継していく。この場合、スレーブノード２４は、隣接するスレーブノード２３へ転送する。なお、マスタノード１１がポート３１からスレーブノード２１へ向けて送信した閉塞箇所数監視制御フレームについても、同様に、スレーブノード間で転送が繰り返される。 The slave node 24 that has received the block number monitoring control frame performs the processing of steps S1 to S9 and relays the block number monitoring control frame. In this case, the slave node 24 transfers to the adjacent slave node 23. Similarly, transfer of the blockage number monitoring control frame transmitted from the port 31 to the slave node 21 by the master node 11 is repeated between the slave nodes.
　（３）閉塞箇所数監視制御フレームがリングを１周すると、マスタノード１１が閉塞箇所数監視制御フレームを受信し、閉塞箇所数監視制御フレームの閉塞箇所数フィールドを確認する。閉塞箇所数フィールドが「２以上」の場合、マスタノード１１は、閉塞ポートの誤設定として、閉塞ポート設定の異常を検出する。また、閉塞箇所数フィールドが「０」、かつ、送信元アドレスが自装置（マスタノード１１）のアドレスの場合、閉塞ポートの誤解除として、閉塞ポート設定の異常（ループ）を検出する。マスタノード１１は、閉塞箇所数フィールドを確認後、閉塞箇所数監視制御フレームを廃棄する。 (3) When the block number monitoring control frame makes one round of the ring, the master node 11 receives the block number monitoring control frame and confirms the block number field of the block number monitoring control frame. When the number of blocked locations field is “2 or more”, the master node 11 detects an abnormality in the blocked port setting as an erroneous setting of the blocked port. Further, when the block location number field is “0” and the transmission source address is the address of the own device (master node 11), a block port setting error (loop) is detected as an erroneous release of the block port. The master node 11 discards the block number monitoring control frame after confirming the block number field.
　ここで、正常なポート設定の場合に上記処理（（１）～（３））を適用した具体例について説明する。図１のリングネットワークにおいて、マスタノード１１から反時計周り方向に閉塞箇所数監視制御フレームを送受信したときの閉塞箇所数フィールドおよびセットフラグフィールドの遷移を図５に示す。図５は、各ノードにおける閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。閉塞箇所数監視制御フレームが各ノードを通過したときの、閉塞箇所数フィールドおよびセットフラグフィールドの遷移を表したものである。この場合、マスタノード１１は、リングネットワークを１周して戻ってきたときの閉塞箇所数フィールドが「１」であるため、閉塞ポート設定が正常であると認識する。実際、マスタノード１１のポート３１のみが閉塞されており、リングネットワーク全体で正常な通信路が確保できている。 Here, a specific example in which the above processing ((1) to (3)) is applied in the case of normal port setting will be described. In the ring network of FIG. 1, FIG. 5 shows the transition of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11. FIG. 5 is a diagram showing the transition of each field of the block number monitoring control frame in each node. This is a diagram showing the transition of the block number field and the set flag field when the block number monitoring control frame passes through each node. In this case, the master node 11 recognizes that the blocked port setting is normal because the number of blocked locations field is “1” when returning around the ring network. Actually, only the port 31 of the master node 11 is blocked, and a normal communication path can be secured in the entire ring network.
　また、図２のリングネットワークにおいて、マスタノード１１から反時計周り方向に閉塞箇所数監視制御フレームを送受信したときの閉塞箇所数フィールドおよびセットフラグフィールドの遷移を図６に示す。図６は、各ノードにおける閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。この場合、ポート３６とポート３５が閉塞されているが、セットフラグフィールドを使用することで、ポート３５の閉塞ポートはカウントしない（図４のフローチャートにおけるステップＳ３：Ｎｏの処理）。よって、マスタノード１１は、リングネットワークを１周して戻ってきたときの閉塞箇所数フィールドが「１」であるため、閉塞ポート設定が正常であると認識する。実際、閉塞ポート数は２つだが、閉塞箇所としては１箇所であり、リングネットワーク全体で正常な通信路が確保できている。 FIG. 6 shows the transition of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11 in the ring network of FIG. FIG. 6 is a diagram illustrating the transition of each field of the block number monitoring control frame in each node. In this case, the port 36 and the port 35 are blocked, but the blocked port of the port 35 is not counted by using the set flag field (step S3: No process in the flowchart of FIG. 4). Therefore, the master node 11 recognizes that the blocked port setting is normal because the number of blocked locations field is “1” when returning around the ring network. Actually, the number of blocked ports is two, but the number of blocked ports is one, and a normal communication path can be secured in the entire ring network.
　つぎに、異常なポート設定の場合に上記処理（（１）～（３））を適用した具体例について説明する。図７のリングネットワークにおいて、マスタノード１１から反時計周り方向に閉塞箇所数監視制御フレームを送受信したときの閉塞箇所数フィールドおよびセットフラグフィールドの遷移を図８に示す。図７は、ループが発生しているリングネットワークを示す図である。また、図８は、各ノードにおける閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。この場合、マスタノード１１は、リングネットワークを１周して戻ってきたときの閉塞箇所数フィールドが「０」であるため、閉塞ポートの誤解除を検出できる。実際、ループが発生し、ブロードキャストフレームが流れ続けて正常な通信ができていない状態である。 Next, a specific example in which the above processing ((1) to (3)) is applied to an abnormal port setting will be described. In the ring network of FIG. 7, FIG. 8 shows transitions of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11. FIG. 7 is a diagram illustrating a ring network in which a loop has occurred. FIG. 8 is a diagram showing transition of each field of the blockage number monitoring control frame in each node. In this case, the master node 11 is able to detect erroneous release of the blocked port because the number of blocked locations field is “0” when returning around the ring network. Actually, a loop occurs and a broadcast frame continues to flow and normal communication cannot be performed.
　また、図９のリングネットワークにおいて、マスタノード１１から反時計周り方向に閉塞箇所数監視制御フレームを送受信していったときの閉塞箇所数フィールドおよびセットフラグフィールドの遷移を図１０に示す。図９は、２つのポートが閉塞しされているリングネットワークを示す図である。また、図１０は、各ノードにおける閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。この場合、マスタノード１１は、リングネットワークを１周して戻ってきたときの閉塞箇所数フィールドが「２」であるため、閉塞ポートの誤解除を検出できる。実際、複数箇所閉塞により経路が分断され、ユーザデータの通信ができないノード間の経路が発生している状態である。 FIG. 10 shows the transition of the block number field and the set flag field when the block number monitoring control frame is transmitted and received counterclockwise from the master node 11 in the ring network of FIG. FIG. 9 is a diagram illustrating a ring network in which two ports are blocked. FIG. 10 is a diagram showing transition of each field of the blockage number monitoring control frame in each node. In this case, the master node 11 is able to detect erroneous release of the blocked port because the number of blocked locations field is “2” when returning around the ring network. Actually, the route is divided due to blockage at a plurality of locations, and a route between nodes that cannot communicate user data is generated.
　つづいて、閉塞ポート設定の異常を検出した場合に、復旧する方法について説明する。閉塞ポート設定の異常を検出した場合、マスタノード１１は、リングネットワークを１周した閉塞箇所数監視制御フレームを受信していることから、リングネットワーク上で双方向のリンク断やノード障害等の障害が発生していないと判断する。そこで、マスタノード１１は以下の処理（１～４）を行う。この場合、閉塞ポートの誤設定、閉塞ポートの誤解除のどちらでも同様の方法で復旧可能である。一例として、図９におけるポート設定の異常からの復旧について説明する。図１１は、異常検出後の復旧処理を示す図である。 Next, how to recover when an abnormality in the blocked port setting is detected will be described. When an abnormality in the blocked port setting is detected, the master node 11 has received a block number monitoring control frame that goes around the ring network. Is determined not to occur. Therefore, the master node 11 performs the following processing (1 to 4). In this case, both the erroneous setting of the blocked port and the erroneous release of the blocked port can be recovered by the same method. As an example, the recovery from the port setting abnormality in FIG. 9 will be described. FIG. 11 is a diagram illustrating a recovery process after abnormality detection.
　１．マスタノード１１は、ポート３１とポート３Ｃの両方とも閉塞していない場合、マスタノードの片方のポート（例えばポート３１）を閉塞する。 1. When both the port 31 and the port 3C are not blocked, the master node 11 blocks one port (for example, the port 31) of the master node.
　２．つぎに、マスタノード１１は、スレーブノード２１，２５に向けて、閉塞ポートの解除を指示するための閉塞解除指示制御フレームを送信する。閉塞箇所数監視制御フレームがリングネットワークを１周したことを確認しているため片方向の送信でも良いが、双方向に送信することが望ましい。 2. Next, the master node 11 transmits a blocking release instruction control frame for instructing the release of the blocking port to the slave nodes 21 and 25. Since it is confirmed that the block number monitoring control frame has made one round of the ring network, transmission in one direction may be performed, but transmission in both directions is desirable.
　３．スレーブノード２１，２５は、閉塞解除指示制御フレームを受信すると、閉塞解除指示制御フレームを受信した方向と逆隣のノード（スレーブノード２２，２４）に転送するとともに、自装置で閉塞しているポートがある場合は閉塞解除する。図１１において、スレーブノード２５は、ポート３Ａの閉塞を解除する。 3. When the slave nodes 21 and 25 receive the blocking release instruction control frame, the slave nodes 21 and 25 transfer the blocking release instruction control frame to the nodes (slave nodes 22 and 24) adjacent to the direction opposite to the direction in which the slave release instruction control frame is received, and the ports blocked by the own device. If there is, release the block. In FIG. 11, the slave node 25 releases the blocking of the port 3A.
　４．閉塞解除指示制御フレームを受信したスレーブノード２２，２４は、上記３．の処理を同様に行う。図１１において、この過程で、スレーブノード２２がポート３４の閉塞を解除する。以降、閉塞解除指示制御フレームを受信した各スレーブノードが上記３．の処理を繰り返し行うことで、閉塞解除指示制御フレームは、リングネットワークを１周し、マスタノード１１に戻る。マスタノード１１は、受信した閉塞解除指示制御フレームを廃棄する。 4. The slave nodes 22 and 24 that have received the block release instruction control frame receive the above 3. The same process is performed. In FIG. 11, in this process, the slave node 22 releases the block of the port 34. Thereafter, each slave node that has received the block release instruction control frame receives the above 3. By repeating this process, the blockage release instruction control frame goes around the ring network and returns to the master node 11. The master node 11 discards the received block release instruction control frame.
　閉塞解除指示制御フレームが１周することで、スレーブノード２１～２５は、ポートを閉塞していない状態となる。また、リングネットワークでは、マスタノード１１のみが１つのポート（ポート３１）を閉塞することとなる。 When the block release instruction control frame makes one round, the slave nodes 21 to 25 are not blocked. In the ring network, only the master node 11 blocks one port (port 31).
　以上説明したように、本実施の形態では、スレーブノード１１が、閉塞箇所数監視制御フレームを用いて閉塞ポート設定の異常を検出し、閉塞解除指示制御フレームを用いて検出した異常を復旧できることとした。これにより、通信障害を迅速に復旧し正常な通信路を確保できるため、リングネットワークの信頼性の向上が可能となる。 As described above, in the present embodiment, the slave node 11 can detect an abnormality in the blocked port setting using the block number monitoring control frame, and can recover the abnormality detected using the block release instruction control frame. did. As a result, a communication failure can be quickly recovered and a normal communication path can be secured, so that the reliability of the ring network can be improved.
実施の形態２．
　実施の形態１では、片方向でも通信路が確保されており、マスタノード１１は、送信した閉塞箇所数監視制御フレームがリンクネットワークを１周して戻ってきた場合に閉塞ポート設定の異常を検出できる。しかし、閉塞箇所数監視制御フレームが戻ってこない場合、マスタノード１１は、リングネットワーク上に何らかの障害があることは検出できるが、閉塞ポート設定の異常を検出できない。本実施の形態では、リングネットワーク上に障害が発生している場合でも、閉塞ポート設定の異常が検出できる方法について説明する。 Embodiment 2. FIG.
In the first embodiment, the communication path is secured even in one direction, and the master node 11 detects an abnormality in the blocked port setting when the transmitted block number monitoring control frame returns around the link network. it can. However, if the block location monitoring control frame does not return, the master node 11 can detect that there is some failure on the ring network, but cannot detect an abnormal block port setting. In the present embodiment, a method for detecting an abnormality in the blocked port setting even when a failure has occurred on the ring network will be described.
　（１）図１２は、リンク４３でリンク断が発生しているリングネットワークを示す図である。マスタノード１１は、送信した閉塞箇所数監視制御フレームが戻ってこないことで、リンク断等の障害を検出できる。この場合、リンク４３と接続するスレーブノード２２，２３では、リンク４３で障害が発生したことを検出できる。障害を検出したスレーブノード２２，２３は、障害を受けている方のポート（ポート３５，３６）を閉塞する。 (1) FIG. 12 is a diagram showing a ring network in which a link break has occurred in the link 43. The master node 11 can detect a failure such as a link disconnection by not returning the transmitted blockage number monitoring control frame. In this case, the slave nodes 22 and 23 connected to the link 43 can detect that a failure has occurred in the link 43. The slave nodes 22 and 23 that have detected the failure block the ports (ports 35 and 36) that have suffered the failure.
　（２）障害を検出したスレーブノード２２，２３は、正常である方のポート（ポート３４，３７）から閉塞箇所数フィールドを「１」として閉塞箇所数監視制御フレームを送信する。このとき、閉塞箇所数監視制御フレームの送信元アドレスは自ノード（スレーブノード２２または２３）のアドレスとなる。 (2) The slave nodes 22 and 23 that have detected the failure transmit the block number monitoring control frame with the block number field set to “1” from the normal port (ports 34 and 37). At this time, the transmission source address of the block number monitoring control frame is the address of the own node (slave node 22 or 23).
　（３）閉塞箇所数監視制御フレームを受信した他のスレーブノード２１，２４，２５は、図４のフローチャートと同様の処理を実行し、閉塞箇所数監視制御フレームの閉塞箇所数フィールドおよびセットフラグフィールドを書き換えて、閉塞箇所数監視制御フレームを、受信した方向と逆隣のノードに転送する。 (3) The other slave nodes 21, 24, 25 that have received the block number monitoring control frame execute the same processing as in the flowchart of FIG. 4, and the block number field and set flag field of the block number monitoring control frame Is rewritten, and the blockage number monitoring control frame is transferred to the node opposite to the received direction.
　（４）マスタノード１１は、閉塞箇所数監視制御フレームを受信すると、送信元アドレスが自ノード（マスタノード１１）ではなく、閉塞箇所数フィールドが「２以上」の場合に、閉塞ポート設定の異常を検出できる。なお、受信した閉塞箇所数監視制御フレームは、実施の形態１と同様に廃棄する。 (4) When the master node 11 receives the block number monitoring control frame, if the transmission source address is not its own node (master node 11) and the block number field is “2 or more”, the blocked port setting error Can be detected. The received block number monitoring control frame is discarded as in the first embodiment.
　図１３は、閉塞箇所数監視制御フレームの流れを示す図である。各ノードにおける上記処理（（１）～（４））の対応を示すものである。また、図１２のリングネットワークにおいて、障害を検出したスレーブノード２３が時計周り方向に送信した閉塞箇所数監視制御フレームの閉塞箇所数フィールドおよびセットフラグフィールドの遷移を図１４に示す。図１４は、各ノードにおける閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。この場合、マスタノード１１は、閉塞箇所数フィールドが「１」であるため、閉塞ポート設定が正常であると認識する。 FIG. 13 is a diagram showing the flow of the blockage number monitoring control frame. The correspondence of the above processing ((1) to (4)) in each node is shown. Also, FIG. 14 shows the transition of the block number field and the set flag field of the block number monitoring control frame transmitted in the clockwise direction by the slave node 23 detecting the failure in the ring network of FIG. FIG. 14 is a diagram illustrating the transition of each field of the block number monitoring control frame in each node. In this case, the master node 11 recognizes that the blocked port setting is normal because the blocked location number field is “1”.
　つぎに、図１５のリングネットワークにおいて、障害を検出したスレーブノード２３が時計周り方向に送信した閉塞箇所数監視制御フレームの閉塞箇所数フィールドおよびセットフラグフィールドの遷移を図１６に示す。図１５は、リングネットワークで複数のポートを閉塞している状態を示す図である。また、図１６は、各ノードにおける閉塞箇所数監視制御フレームの各フィールドの遷移を示す図である。この場合、マスタノード１１は、閉塞箇所数フィールドが「２」であるため、閉塞ポート設定の異常（閉塞ポートの誤設定）を検出できる。 Next, in the ring network of FIG. 15, the transition of the block number field and the set flag field in the block number monitoring control frame transmitted in the clockwise direction by the slave node 23 detecting the failure is shown in FIG. FIG. 15 is a diagram illustrating a state where a plurality of ports are blocked in the ring network. FIG. 16 is a diagram showing transition of each field of the blockage number monitoring control frame in each node. In this case, the master node 11 can detect an abnormality in the blocked port setting (incorrect setting of the blocked port) because the number of blocked locations field is “2”.
　このような場合においても、閉塞ポート設定の異常を早期に検出するため、障害を検出した両側のノード（例えば、図１２の場合のスレーブノード２２，２３）が、障害が継続している間、周期的に閉塞箇所数監視制御フレームを送信することが望ましい。 Even in such a case, in order to detect an abnormality in the blocked port setting at an early stage, the nodes on both sides (for example, the slave nodes 22 and 23 in FIG. It is desirable to periodically transmit the blockage number monitoring control frame.
　マスタノード１１は、自ノード（マスタノード１１）が送信した閉塞箇所数監視制御フレームが戻ってこないこと、または、送信元アドレスが自ノード（マスタノード１１）でない閉塞箇所数監視制御フレームを受信したことで、リングネットワーク上に何らかの障害があることを検出することは可能である。 The master node 11 has not received the block location monitoring control frame transmitted by its own node (master node 11), or has received a block location monitoring control frame whose source address is not its own node (master node 11). Thus, it is possible to detect that there is some failure on the ring network.
　ここで、障害発生時の閉塞ポート設定の異常であることを明確にし、障害が発生していない場合の閉塞ポート設定の異常と区別するため、閉塞箇所数監視制御フレームに、障害発生の理由によって閉塞中であることを示すフィールド（障害発生による閉塞中）を追加する方法がある。図１７は、閉塞箇所数監視制御フレームの構成例を示す図である。障害発生による閉塞中のフィールドが追加されている。障害を検出したスレーブノードは、送信時に障害発生による閉塞中を「１」にセットし、中継するスレーブノードでは値を変更しない。 Here, in order to clarify that it is an abnormality of the blocked port setting at the time of failure occurrence and to distinguish it from an abnormality of the blocked port setting when no failure has occurred, in the block number monitoring control frame, depending on the reason for the failure occurrence There is a method of adding a field (blocking due to the occurrence of a failure) indicating that it is blocked. FIG. 17 is a diagram illustrating a configuration example of a block number monitoring control frame. A field that is blocked due to a failure has been added. The slave node that has detected the failure sets “1” to “blocking” due to the occurrence of the failure at the time of transmission, and the slave node that relays does not change the value.
　これにより、マスタノード１１は、受信した閉塞箇所数監視制御フレームの障害発生による閉塞中および閉塞箇所数フィールドを見て、障害発生による閉塞中が「１」、かつ閉塞箇所数フィールドが「２以上」のとき、障害発生中の閉塞ポート設定の異常を検出することができる。 As a result, the master node 11 sees the blockage due to failure occurrence and the blockage location number field in the received blockage number monitoring control frame received, the blockage due to failure occurrence is “1”, and the blockage location number field is “2 or more. ", It is possible to detect an abnormality in the blocked port setting during the occurrence of a failure.
　つづいて、障害発生中の閉塞ポート設定の異常を検出した場合に、復旧する方法について説明する。 Next, we will explain how to recover when an error is detected in the blocked port setting during the failure.
　１．まず、障害発生中の閉塞ポート設定の異常を検出したマスタノード１１は、自ノードで障害を検出していないがポートを閉塞している場合、ポートの閉塞を解除する（例えばポート３１が閉塞していた場合、ポート３１の閉塞を解除する）。 1. First, the master node 11 that has detected an abnormality in the blocked port setting during the occurrence of a failure does not detect a failure in its own node but blocks the port (for example, the port 31 is blocked). If so, the port 31 is unblocked).
　２．つぎに、マスタノード１１は、閉塞解除指示制御フレームをスレーブノード２１の方向（時計周り）およびスレーブノード２５の方向（反時計周り）の双方向に送信する。 2. Next, the master node 11 transmits the blocking release instruction control frame in both directions of the slave node 21 (clockwise) and the slave node 25 (counterclockwise).
　３．スレーブノード２１，２５は、閉塞解除指示制御フレームを受信すると、受信した方向と逆隣のノードに転送するとともに、自装置で閉塞しているポートがある場合は閉塞解除する。 3. When the slave nodes 21 and 25 receive the block release instruction control frame, the slave nodes 21 and 25 transfer the block to the node adjacent to the direction opposite to the received direction, and release the block if there is a port blocked by the own device.
　４．障害を検出した両側のノード（例えばスレーブノード２２，２３）では、障害を検出したポート（ポート３５，３６）の閉塞を解除せず、閉塞解除指示制御フレームを廃棄する。 4. The nodes on both sides (for example, slave nodes 22 and 23) that detected the failure do not release the block of the ports (ports 35 and 36) that detected the failure, but discard the block release instruction control frame.
　閉塞解除指示制御フレームが障害を検出したノード（スレーブノード２２，２３）まで届くことで、リングネットワークでは、障害を検出したノード（スレーブノード２２，２３）のポート（ポート３５，３６）だけが閉塞することとなる。 When the blocking release instruction control frame reaches the node (slave nodes 22 and 23) where the failure is detected, only the ports (ports 35 and 36) of the node (slave nodes 22 and 23) where the failure is detected are blocked in the ring network. Will be.
　以上説明したように、本実施の形態では、リンク断やノード障害等の障害発生時においても閉塞ポート設定の異常を検出し、検出した異常を復旧できることとした。これにより、通信障害を迅速に復旧し正常な通信路を確保できるため、リングネットワークの信頼性の向上が可能となる。 As described above, in this embodiment, it is possible to detect an abnormality in the blocked port setting even when a failure such as a link break or a node failure occurs, and to recover the detected abnormality. As a result, a communication failure can be quickly recovered and a normal communication path can be secured, so that the reliability of the ring network can be improved.
　なお、マスタノードはリングネットワーク上の１つに特定する必要はなく、マスタノードと同様な処理を行うサブマスタノードを設定しても良い。または、全てのノードがマスタノードと同様な処理を行い、全てのノードで閉塞ポート設定異常を検出することも可能である。 Note that the master node does not need to be specified as one on the ring network, and a sub-master node that performs the same processing as the master node may be set. Alternatively, all nodes can perform the same process as the master node, and all nodes can detect a blocked port setting error.
実施の形態３．
　実施の形態１および２では、リングネットワーク上においてマスタノードを１つだけ設定しており、マスタノードが故障しておらず、制御フレームの送受信と閉塞ポート設定の異常の検出が可能であることが前提である。しかし、マスタノードをリングネットワーク上に１つしか設定していない場合、マスタノードの故障時、マスタノードの両側のリンクが切れて通信不可になると、リングネットワーク上の閉塞ポート設定の異常を検出できない。本実施の形態では、予備のマスタノードを設定する場合について説明する。 Embodiment 3 FIG.
In the first and second embodiments, only one master node is set on the ring network, the master node is not broken, and it is possible to detect transmission / reception of control frames and abnormalities in blocked port settings. It is a premise. However, when only one master node is set on the ring network, if the master node fails and the links on both sides of the master node are disconnected and communication is not possible, an abnormality in the blocked port setting on the ring network cannot be detected. . In this embodiment, a case where a spare master node is set will be described.
　図１８は、リングネットワークでマスタノード１１が故障した状態を示す図である。このような場合、マスタノード１１の両側のリンクが切れてしまい通信不可になり、リングネットワーク上の閉塞ポート設定の異常を検出できない。 FIG. 18 is a diagram showing a state in which the master node 11 has failed in the ring network. In such a case, the links on both sides of the master node 11 are disconnected, making communication impossible, and it is impossible to detect an abnormality in the blocked port setting on the ring network.
　本実施の形態では、マスタノード１１が故障した場合に備えて、スレーブノードのうちの少なくとも１つを予備のマスタノード（一例としてスレーブノード２３とする）として設定し、閉塞箇所数監視制御フレームの送信、および閉塞ポート設定の異常の検出が可能とする。予備のマスタノードを設定した場合、例えば予備のマスタノード（スレーブノード２３）とマスタノード１１の間で制御フレームを周期的に送受する。予備のマスタノード（スレーブノード２３）は、マスタノード１１からの制御フレームが到達しなくなった場合にマスタノード１１が故障していると見なすなどの方法により、マスタノード１１の正常性を監視する。 In this embodiment, in preparation for the case where the master node 11 fails, at least one of the slave nodes is set as a spare master node (slave node 23 as an example), and the block number monitoring control frame It is possible to detect errors in transmission and blocked port settings. When a spare master node is set, for example, control frames are periodically transmitted and received between the spare master node (slave node 23) and the master node 11. The spare master node (slave node 23) monitors the normality of the master node 11 by a method such as assuming that the master node 11 has failed when the control frame from the master node 11 does not reach.
　図１９は、マスタノード１１と予備のマスタノード（スレーブノード２３）間での制御フレームの送受信を示す図である。また、図２０は、予備のマスタノード（スレーブノード２３）がマスタノードとして動作している状態を示す図である。マスタノード１１が故障している場合に限り、予備のマスタノード（スレーブノード２３）がマスタノードとして、実施の形態１および２で説明した処理を行う。マスタノード１１が故障していないかどうかを確認する方法としては、イーサネット（登録商標）では、イーサネット（登録商標）ＯＡＭの機能であるＣＣ（Continuity　Check）機能を用いても良い。 FIG. 19 is a diagram illustrating transmission and reception of control frames between the master node 11 and a spare master node (slave node 23). FIG. 20 is a diagram illustrating a state in which a spare master node (slave node 23) is operating as a master node. Only when the master node 11 is out of order, the spare master node (slave node 23) is the master node and performs the processing described in the first and second embodiments. As a method for confirming whether or not the master node 11 has failed, the Ethernet (registered trademark) may use a CC (Continuity Check) function that is a function of the Ethernet (registered trademark) OAM.
　実施の形態１において、閉塞ポート設定の異常の検出までは、閉塞箇所数監視制御フレームを送信するのはどのノードからでも良く、例えば予備のマスタノートを複数設定した場合、予備のマスタノードが全てマスタノードとして動作しても、各ノードは、送信元アドレスが自装置のアドレスであれば閉塞ポート設定の異常の有無を確認することで異常を検出できる。しかし、閉塞ポート設定の異常からの復旧、また、実施の形態２では、リングネットワーク上の１つのノードのみが、マスタノードとして制御フレームを終端し復旧時に閉塞する処理が必要である。そのため、予備のマスタノードを複数設定した場合、予備のマスタノードに優先順位をつけ、優先度の低いマスタノードは、他の優先度の高いマスタノードが全て故障している場合に限り、マスタノードして動作する。 In the first embodiment, until the detection of the abnormality of the blocked port setting, any node may transmit the blocked point number monitoring control frame. For example, when a plurality of spare master notes are set, all the spare master nodes are transmitted. Even when operating as a master node, each node can detect an abnormality by checking whether there is an abnormality in the blocked port setting if the transmission source address is the address of its own device. However, it is necessary to recover from a blocked port setting abnormality, and in the second embodiment, only one node on the ring network needs to terminate the control frame as a master node and block at the time of recovery. Therefore, when multiple spare master nodes are set, priorities are assigned to the spare master nodes, and a master node with a lower priority is assigned to the master node only when all other master nodes with higher priorities have failed. Works.
　以上説明したように、本実施の形態では、マスタノード故障時にも、閉塞ポートの設定異常を検出し、検出した異常を復旧できることとした。これにより、通信障害を迅速に復旧し正常な通信路を確保できるため、リングネットワークの信頼性の向上が可能となる。 As described above, according to the present embodiment, it is possible to detect a blocked port setting error and recover the detected error even when the master node fails. As a result, a communication failure can be quickly recovered and a normal communication path can be secured, so that the reliability of the ring network can be improved.
　以上のように、本発明にかかるリングネットワーク制御方法は、高信頼化を実現するリングネットワークに有用であり、特に、閉塞ポート設定の異常検出と復旧を可能とするリングネットワークとして適している。 As described above, the ring network control method according to the present invention is useful for a ring network that achieves high reliability, and is particularly suitable as a ring network that enables detection and recovery of an abnormality in a blocked port setting.

Claims (15)

  1. 　通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおけるリングネットワーク制御方法であって、
    　前記マスタノードが、閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを、隣接するスレーブノードに送信する制御フレーム送信ステップと、
    　制御フレームを受信したスレーブノードが、閉塞ポートがある場合に当該制御フレームの閉塞箇所数のフィールドを書き換え、その後、書き換え後の制御フレームを、送信元ノード以外のノードに転送する制御フレーム転送ステップと、
    　制御フレームがリングネットワークを一周して前記マスタノードに戻ってきた場合、当該マスタノードが、受信した制御フレームの閉塞箇所数のフィールドを確認し、閉塞ポート設定の正常または異常を検出する検出ステップと、
    　閉塞ポート設定の異常が検出された場合に、前記マスタノードが、自装置のポートを閉塞していないときは少なくとも１つのポートを閉塞するポート閉塞ステップと、
    　前記マスタノードが、スレーブノードに向けて、閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを送信する閉塞解除送信ステップと、
    　閉塞解除制御フレームを受信したスレーブノードが、自装置に閉塞ポートがある場合にそのポートの閉塞を解除し、また、当該閉塞解除制御フレームを、送信元ノード以外のノードに転送する閉塞解除転送ステップと、
    　を含むことを特徴とするリングネットワーク制御方法。     A plurality of nodes having two or more ports for performing communication are connected in a ring shape, at least one node is a master node that monitors the state of the network, and the other nodes are slave nodes that follow instructions of the master node A ring network control method in a ring network,
    A control frame transmission step in which the master node transmits a control frame having a field of the number of blocked locations indicating the number of blocked ports to an adjacent slave node;
    A control frame transfer step in which the slave node that has received the control frame rewrites the field of the number of blocked points in the control frame when there is a blocked port, and then transfers the rewritten control frame to a node other than the transmission source node; ,
    When the control frame goes around the ring network and returns to the master node, the master node confirms the field of the number of blocked locations in the received control frame and detects whether the blocked port setting is normal or abnormal. ,
    A port blocking step of blocking at least one port when the master node does not block a port of its own device when an abnormality of the blocked port setting is detected;
    The master node sends a blocking release control frame for instructing the slave node to release the blocking of the blocking port; and
    Block release transfer step in which the slave node that has received the block release control frame releases the block of the port when there is a block port in its own device, and forwards the block release control frame to a node other than the transmission source node When,
    A ring network control method comprising:
  2. 　通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおけるリングネットワーク制御方法であって、
    　隣接するノードまたは伝送路において障害を検出したスレーブノードが、障害が発生しているノードまたは伝送路に接続されたポートを閉塞し、閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを、閉塞ポート以外のポートに接続されたノードに送信する制御フレーム送信ステップと、
    　制御フレームを受信したスレーブノードが、閉塞ポートがある場合に当該制御フレームの閉塞箇所数のフィールドを書き換え、その後、書き換え後の制御フレームを、送信元ノード以外のノードに転送する制御フレーム転送ステップと、
    　制御フレームを受信したマスタノードが、当該制御フレームの閉塞箇所数のフィールドを確認し、閉塞ポート設定の正常または異常を検出する検出ステップと、
    　閉塞ポート設定の異常が検出された場合に、前記マスタノードが、自装置のポートを閉塞していないときは少なくとも１つのポートを閉塞するポート閉塞ステップと、
    　前記マスタノードが、スレーブノードに向けて、閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを送信する閉塞解除送信ステップと、
    　閉塞解除制御フレームを受信した障害を検出していないスレーブノードが、自装置に閉塞ポートがある場合にそのポートの閉塞を解除し、また、当該閉塞解除制御フレームを、送信元ノード以外のノードに転送する閉塞解除転送ステップと、
    　閉塞解除制御フレームを受信した障害を検出しているスレーブノードが、障害による閉塞ポート以外に自装置に閉塞ポートがある場合にそのポートの閉塞を解除し、また、当該閉塞解除制御フレームを廃棄する閉塞解除廃棄ステップと、
    　を含むことを特徴とするリングネットワーク制御方法。     A plurality of nodes having two or more ports for performing communication are connected in a ring shape, at least one node is a master node that monitors the state of the network, and the other nodes are slave nodes that follow instructions of the master node A ring network control method in a ring network,
    A slave node that has detected a failure in an adjacent node or transmission path blocks a port connected to the node or transmission path in which the failure has occurred, and a control frame having a field of the number of blocked locations indicating the number of blocked ports, A control frame transmission step for transmitting to a node connected to a port other than the blocked port;
    A control frame transfer step in which the slave node that has received the control frame rewrites the field of the number of blocked points in the control frame when there is a blocked port, and then transfers the rewritten control frame to a node other than the transmission source node; ,
    A detection step in which the master node that has received the control frame confirms the field of the number of blocked locations in the control frame and detects whether the blocked port setting is normal or abnormal;
    A port blocking step of blocking at least one port when the master node does not block a port of its own device when an abnormality of the blocked port setting is detected;
    The master node sends a blocking release control frame for instructing the slave node to release the blocking of the blocking port; and
    If a slave node that has received a block release control frame and has not detected a failure has a blocked port on its own device, the slave node releases the block, and sends the block release control frame to a node other than the source node. A deblocking transfer step to transfer, and
    When a slave node that has detected a failure that has received a block release control frame has a blocked port on its own device other than the blocked port due to the failure, the slave node releases the block and discards the block release control frame. An occlusion release disposal step;
    A ring network control method comprising:
  3. 　前記リングネットワークでは、少なくとも１つのスレーブノードを予備のマスタノードとして設定し、マスタノードが故障した場合に、予備のマスタノードがマスタノードの処理を行うことを特徴とする請求項１または２に記載のリングネットワーク制御方法。 3. The ring network according to claim 1, wherein at least one slave node is set as a spare master node in the ring network, and when the master node fails, the spare master node performs processing of the master node. Ring network control method.
  4. 　通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおける前記マスタノードであって、
    　閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを、隣接するスレーブノードに送信する制御フレーム送信手段と、
    　前記制御フレームがリングネットワークを一周して戻ってきた場合に、受信した制御フレームの閉塞箇所数のフィールドを確認し、閉塞ポート設定の正常または異常を検出する検出手段と、
    　を備えることを特徴とするマスタノード。     A plurality of nodes having two or more ports for performing communication are connected in a ring shape, at least one node is a master node that monitors the state of the network, and the other nodes are slave nodes that follow instructions of the master node The master node in the ring network,
    Control frame transmission means for transmitting a control frame having a field of the number of blocked locations indicating the number of blocked ports to an adjacent slave node;
    When the control frame returns around the ring network, a detection unit that checks the field of the number of blocked locations in the received control frame and detects normality or abnormality of the blocked port setting;
    A master node comprising:
  5. 　さらに、
    　閉塞ポート設定の異常が検出され、かつ自装置のポートを閉塞していない場合に、少なくとも１つのポートを閉塞するポート閉塞手段と、
    　前記ポート閉塞手段により少なくとも１つのポートを閉塞後、スレーブノードに向けて、閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを送信する閉塞解除送信手段と、
    　を備えることを特徴とする請求項４に記載のマスタノード。     further,
    Port blocking means for blocking at least one port when an abnormality of the blocked port setting is detected and the port of the own device is not blocked;
    After closing at least one port by the port blocking means, the blocking release transmitting means for sending a blocking release control frame for instructing the blocking node to release the blocking,
    The master node according to claim 4, comprising:
  6. 　通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおける前記マスタノードであって、
    　閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを受信した場合に、当該制御フレームの閉塞箇所数のフィールドを確認し、閉塞ポート設定の正常または異常を検出する検出手段、
    　を備えることを特徴とするマスタノード。     A plurality of nodes having two or more ports for performing communication are connected in a ring shape, at least one node is a master node that monitors the state of the network, and the other nodes are slave nodes that follow instructions of the master node The master node in the ring network,
    A detection unit that, when receiving a control frame having a block number field indicating the number of blocked ports, checks the block number field of the control frame and detects whether the blocked port setting is normal or abnormal;
    A master node comprising:
  7. 　さらに、
    　閉塞ポート設定の異常が検出され、かつ自装置のポートを閉塞していない場合に、少なくとも１つのポートを閉塞するポート閉塞手段と、
    　前記ポート閉塞手段により少なくとも１つのポートを閉塞後、スレーブノードに向けて、閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを送信する閉塞解除送信手段と、
    　を備えることを特徴とする請求項６に記載のマスタノード。     further,
    Port blocking means for blocking at least one port when an abnormality of the blocked port setting is detected and the port of the own device is not blocked;
    After closing at least one port by the port blocking means, the blocking release transmitting means for sending a blocking release control frame for instructing the blocking node to release the blocking,
    The master node according to claim 6, comprising:
  8. 　通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおける前記スレーブノードであって、
    　閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを受信し、かつ閉塞ポートがある場合に、当該制御フレームの閉塞箇所数のフィールドを書き換え、その後、書き換え後の制御フレームを送信元ノード以外のノードに転送する制御フレーム転送手段、
    　を備えることを特徴とするスレーブノード。     A plurality of nodes having two or more ports for performing communication are connected in a ring shape, at least one node is a master node that monitors the state of the network, and the other nodes are slave nodes that follow instructions of the master node The slave node in the ring network,
    When a control frame having the blockage number field indicating the blockage port number is received and there is a blockage port, the blockage number field of the control frame is rewritten, and then the rewritten control frame is other than the source node. Control frame transfer means for transferring to a node of
    A slave node comprising:
  9. 　さらに、
    　閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを受信し、かつ自装置に閉塞ポートがある場合に、そのポートの閉塞を解除し、また、当該閉塞解除制御フレームを送信元ノード以外のノードに転送する閉塞解除転送手段、
    　を備えることを特徴とする請求項８に記載のスレーブノード。     further,
    When a blocking release control frame for instructing to release blocking of a blocked port is received and there is a blocked port in the local device, the blocking of that port is released, and the blocking release control frame is sent to other than the source node Block release transfer means to transfer to the node,
    The slave node according to claim 8, comprising:
  10. 　通信を行うための２つ以上のポートを備えた複数のノードがリング状に接続され、少なくとも１つのノードをネットワークの状態を監視するマスタノードとし、他のノードをマスタノードの指示に従うスレーブノードとするリングネットワークにおける前記スレーブノードであって、
    　隣接するノードまたは伝送路において障害を検出した場合に、障害が発生しているノードまたは伝送路に接続されたポートを閉塞し、閉塞ポート数を表す閉塞箇所数のフィールドを持つ制御フレームを、閉塞ポート以外のポートに接続されたノードに送信する制御フレーム送信手段と、
    　他のノードから制御フレームを受信し、かつ閉塞ポートがある場合に、当該制御フレームの閉塞箇所数のフィールドを書き換え、その後、書き換え後の制御フレームを送信元ノード以外のノードに転送する制御フレーム転送手段と、
    　を備えることを特徴とするスレーブノード。     A plurality of nodes having two or more ports for performing communication are connected in a ring shape, at least one node is a master node that monitors the state of the network, and the other nodes are slave nodes that follow instructions of the master node The slave node in the ring network,
    When a fault is detected in an adjacent node or transmission path, the node connected to the faulty node or transmission path is blocked, and a control frame with a block number field indicating the number of blocked ports is blocked. Control frame transmission means for transmitting to a node connected to a port other than the port;
    When a control frame is received from another node and there is a blocked port, the field for the number of blocked locations in the control frame is rewritten, and then the rewritten control frame is transferred to a node other than the source node Means,
    A slave node comprising:
  11. 　さらに、
    　障害を検出していないときに閉塞ポートの閉塞解除を指示するための閉塞解除制御フレームを受信し、かつ自装置に閉塞ポートがある場合に、そのポートの閉塞を解除し、また、当該閉塞解除制御フレームを送信元ノード以外のノードに転送する閉塞解除転送手段と、
    　障害を検出しているときに前記閉塞解除制御フレームを受信し、かつ障害による閉塞ポート以外に自装置に閉塞ポートがある場合に、そのポートの閉塞を解除し、また、当該閉塞解除制御フレームを廃棄する閉塞解除廃棄手段と、
    　を備えることを特徴とする請求項１０に記載のスレーブノード。     further,
    If a blockage release control frame for instructing blockage release of a blocked port is received when no failure is detected, and there is a blocked port in the local device, the port is released and the blockage is released. Block release transfer means for transferring the control frame to a node other than the transmission source node;
    When a failure is detected, the block release control frame is received, and when there is a blocked port in the own device other than the blocked port due to the failure, the block of the port is released, and the block release control frame is A blocking release discarding means for discarding;
    The slave node according to claim 10, comprising:
  12. 　予備のマスタノードとして設定された状態でマスタノードが故障した場合には、マスタノードの処理を行うことを特徴とする請求項８～１１のいずれか１つに記載のスレーブノード。 The slave node according to any one of claims 8 to 11, wherein when the master node fails while being set as a spare master node, processing of the master node is performed.
  13. 　請求項５に記載のマスタノードと、
    　請求項９に記載の複数のスレーブノードと、
    　を備えることを特徴とするリングネットワーク。     A master node according to claim 5;
    A plurality of slave nodes according to claim 9;
    A ring network comprising:
  14. 　請求項７に記載のマスタノードと、
    　請求項１１に記載の複数のスレーブノードと、
    　を備えることを特徴とするリングネットワーク。     A master node according to claim 7;
    A plurality of slave nodes according to claim 11;
    A ring network comprising:
  15. 　少なくとも１つのスレーブノードを予備のマスタノードとして設定し、マスタノードが故障した場合に、予備のマスタノードがマスタノードの処理を行うことを特徴とする請求項１３または１４に記載のリングネットワーク。 15. The ring network according to claim 13 or 14, wherein at least one slave node is set as a spare master node, and when the master node fails, the spare master node performs processing of the master node.
PCT/JP2009/053214 2009-02-23 2009-02-23 Ring network control method, master node, slave node, and ring network WO2010095268A1 (en)

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