WO2006027824A1

WO2006027824A1 - Communication network system and trouble detecting apparatus

Info

Publication number: WO2006027824A1
Application number: PCT/JP2004/012948
Authority: WO
Inventors: Makoto Isoda; Hironori Terauchi; Tetsuya Yokotani
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2004-09-06
Filing date: 2004-09-06
Publication date: 2006-03-16

Abstract

A communication network system capable of quickly detecting any trouble that occurs in a Layer 2 network having a ring-shaped network topology. In a communication network system of an open ring shape, virtual LANs (1-3,11-13) connecting a master node (20A) and slave nodes (30A-30C) are established in two different communication path directions along the ring for each set of the master node (20A) and a respective one of the slave nodes (30A-30C), and the ports at the link ends of the master node (20A) and slave node (30C) are blocked. The master node (20A) and slave nodes (30A-30C) each have two communication ports for transmitting and receiving information via adjacent links and a trouble detection part for detecting any communication troubles, and causes one of the communication ports that is different from the other one receiving a communication trouble to transmit/forward communication trouble information.

Description

Specification

Communication network system and failure detection apparatus

Technical field

The present invention relates to a communication network system and a failure detection apparatus that detect and avoid failures in a communication network.

Background art

In recent years, with the progress of communication technology, it has become possible to send and receive information between a plurality of communication networks. For example, in order to cope with a link failure or a layer 2 switch failure in a layer 2 network, the layer 2 switch is connected in a ring type or mesh type for redundancy. Then, by using STP (Spanning Tree Protocol), a logical tree (spanning tree) is constructed so that a communication loop does not occur in the path connecting multiple links, and layer 2 on the communication network is formed. MAC (Media used for communication between switches, etc.)

(Access Control) Frames can be protected from infinite patrol (no rape).

[0003] In a communication network with multiple Layer 2 switches connected to a higher level network and lower level networks, when a failure occurs in a Layer 2 switch, BPDU (Bridge Protocol Data Unit) is performed according to STP between the Layer 2 switches. ), A new communication path that circumvents (avoids) the failure is set, and the scanning tree is reconfigured (for example, Non-Patent Document 1).

[0004] In addition, the network transfer system described in Patent Document 1 connects a plurality of nodes that communicate with each other through a plurality of virtual networks without a path forming a loop, and a plurality of nodes are connected via a virtual network. Node is forwarding packets. In the network forwarding system, a broadcast packet for diagnosis is sent to one node active VLAN. A failure between L2 switches is detected by the failure to receive a broadcast packet for diagnosis at another node, and the working VLAN is switched.

[0005] Non-Patent Document 1: Rich Seifert, “Extensive Explanation of LAN Switching”, Nikkei Business Publications, Inc. August 6, 2001 P. 192-211 Patent Document 1: Japanese Patent Laid-Open No. 2003-158539

Disclosure of the invention

Problems to be solved by the invention

However, the detouring of the layer 2 switch failure by STP described in Non-Patent Document 1 has a problem that it takes a long time for the reconfiguration process of the spanning tree to converge.

. In addition, STP is assumed to operate quasi-statically in the network, and the reconfiguration process of the spanning tree is not performed frequently. For this reason, there is a problem that the reconfiguration process of the spanning tree does not converge when the link of the lower layer is unstable and frequently disconnected, or when the logical / physical network topology is frequently changed. It was. In addition, if the communication quality of the lower layer is unstable and the communication quality deteriorates frequently, it is not recognized as a failure, so STP cannot be applied to setting a detour route based on the communication quality. There was a problem.

[0007] In addition, the network transfer system described in Patent Document 1 has a problem in that failure detection cannot be performed in detail for each set of a master node and a slave node.

[0008] The present invention has been made in view of the above, and in a layer 2 network having a ring network topology, failure detection, failure notification to the layer 2 switch, and failure bypass path setting can be performed at high speed. The purpose is to obtain a communication network system and failure detection device that can be used.

Means for solving the problem

[0009] In order to solve the above-described problems and achieve the object, the present invention includes a master node connected to an upper network and a slave node connected to a lower network as layer 2 switches connected in a ring shape, A virtual LAN connecting the master node and the slave node is set in two different communication path directions along the ring for every combination of the slave nodes with respect to the master node, and the master node or An open-ring communication network system in which a set of ports at a link end in the ring of the slave node is blocked, wherein the master node and the slave node are configured to transmit information between adjacent links adjacent to their own nodes. Two communication ports for sending and receiving and receiving via the communication port Detection of communication failure based on information A failure detection unit configured to transmit communication failure information related to the communication failure to a communication port different from the communication port that received the information when the communication failure is detected when the communication failure is detected. And when the communication port receives the communication failure information from another node, the communication port is configured to transfer the communication failure information to a communication port different from the communication port that has received the communication failure information. .

[0010] According to the communication network system according to the present invention, the occurrence of a failure is monitored by transmitting and receiving communication failure information between all nodes in the ring, so that a communication failure can be detected for each node. It becomes possible.

The invention's effect

[0011] According to the communication network system that is effective in the present invention, it becomes possible to detect a communication failure for every node in the ring, and since the communication failure information is transferred between the nodes, all the nodes can be quickly operated. It is possible to detect a failure between nodes.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration of a network system according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a VLAN configuration of the network system according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a master node according to the first embodiment.

FIG. 4 is a block diagram showing a configuration of a slave node according to the first embodiment.

[FIG. 5] FIG. 5 is a flowchart showing the procedure for transmitting and receiving information in the network system (

1).

[Fig. 6] Fig. 6 is a flowchart showing the procedure for sending and receiving information in the network system (

2).

FIG. 7 is a diagram showing a structure of a MAC frame.

[FIG. 8] FIG. 8 is a diagram showing a configuration of a MAC frame to which one VLAN tag is assigned.

FIG. 9 is a diagram showing a configuration of a MAC frame to which two VLAN tags are assigned.

FIG. 10 is a flowchart showing a failure detection procedure according to the first embodiment.

FIG. 11 is a diagram showing a configuration of a network system having a plurality of master nodes. is there.

FIG. 12 is a diagram showing a VLAN configuration of a network system having a plurality of master nodes.

FIG. 13 is a flowchart showing a failure detection procedure according to the second embodiment.

FIG. 14 is a flowchart showing a failure detection procedure according to the third embodiment.

FIG. 15 is a block diagram showing a configuration of a master node according to the fourth embodiment.

FIG. 16 is a flowchart (1) showing a failure detection procedure according to the fourth embodiment.

FIG. 17 is a flowchart (2) showing a procedure of fault detection according to the fourth embodiment.

FIG. 18 is a diagram showing a configuration of topology information set in the master node.

FIG. 19 is a flowchart showing a procedure for switching VLANs after failure detection according to the fifth embodiment.

FIG. 20 is a diagram showing a configuration of VLAN table information set in the master node.

FIG. 21 is a diagram (1) showing a configuration of VLAN table information set in the slave node.

FIG. 22 is a diagram (2) showing a configuration of VLAN table information set in the slave node.

FIG. 23 is a diagram (3) showing a configuration of VLAN table information set in the slave node.

FIG. 24 is a diagram showing a configuration of topology information whose settings have been changed to a master node.

FIG. 25 is a diagram (1) showing a configuration of VLAN table information whose setting has been changed to a slave node.

FIG. 26 is a diagram (2) showing a configuration of VLAN table information whose setting is changed to a slave node.

[FIG. 27] FIG. 27 shows the configuration of VLAN table information whose settings have been changed to slave nodes. It is figure (3).

FIG. 28 is a diagram showing a configuration of VLAN table information whose setting has been changed to a master node.

FIG. 29 is a diagram showing a configuration of the network system shown in FIG. 2 after VLAN switching.

FIG. 30 is a flowchart showing a procedure for switching VLANs after failure detection according to the sixth embodiment.

FIG. 31 is a flowchart showing a procedure for switching VLANs after failure detection according to the seventh embodiment.

FIG. 32 is a flowchart showing a procedure for switching VLANs after failure detection according to the eighth embodiment.

FIG. 33 is a flowchart showing a procedure for switching VLANs after failure detection according to the ninth embodiment.

FIG. 34 is a diagram showing a configuration of the network system shown in FIG. 12 after VLAN switching.

FIG. 35 is a flowchart showing a VLAN switching procedure after failure detection according to the tenth embodiment. Explanation of symbols

1−3, 11 1 13, 51, 61, 62, 75 Virtual LAN

20A, 20B master node

21 Forward port

22 Reverse port

23 Switch part

24 Tag processing section

25 VLAN processing section

26 Memory

27 Lower network communication section

27 Upper network communication section 28 Connection judgment part

29 Control unit

30A—30C slave node

32 Lower network communication section

55 Blocked link

80—82 MAC frames

85A, 85X, 86A—86C, 86X—86Z VLAN table information

87A, 87X topology information

90 ring network

201A, 201B Host network

301A— 301C Subnetwork

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] Hereinafter, embodiments of a communication network system and a failure detection apparatus 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.

[0015] Embodiment 1.

FIG. 1 is a diagram showing a configuration of a network system according to Embodiment 1 of the present invention. The network system includes a ring network 90 and a plurality of communication networks connected to the ring network 90. The ring network 90 includes a master node 20A and slave nodes 30A-30C. The master node 20A and slave nodes 30A-30C are layer 2 switches.

Master node 20A and slave nodes 30A-30C relay information in the network system. The master node 20A and the slave nodes 30A-30C determine the packet transmission destination based on the data link layer (second layer) data of the OSl (Open System Interconnection) reference model, and transfer the packet.

[0017] As a data link layer protocol, Ethernet (registered trademark) or other MAC (Media

Access Control) is used. Then, the node in the network system determines the data transmission destination based on the MAC address! In the ring network 90, the master node 20A and the slave nodes 30A-30C are connected in a ring shape. Slave node 30A is connected to master node 20A and slave node 30B, and slave node 30C is connected to master node 20A and slave node 30B.

[0019] In order to put the ring network 90 in which the plurality of nodes are connected in a ring shape into an open loop, the ports at both ends of one link are logically blocked. Here, the ports at both ends of the link connecting the master node 20A and the slave node 30C (the slave node 30C side port in the master node 20A and the master node 20A side port in the slave node 30C) are logically blocked. This shows a case where the master node 20A and the slave node 30C are connected by the blocked link 55. That is, the master node 20A and the slave node 30C are nodes at both ends of the blocked link 55 (hereinafter referred to as ring end nodes). The ports at both ends of the blocked link 55 may be physically disconnected.

[0020] Master node 20A is connected to upper network 201A. Slave node 30A is connected to lower network 301A, slave node 30B is connected to lower network 301B, and slave node 30C is connected to lower network 301C.

In the network system, the ring network 90 relays communication between the upper network 201A and the lower networks 301A-301C. Also, the occurrence of a fault in the network system is detected by transmitting and receiving information between the master node 2 OA and slave nodes 30A-30C.

Master node 20A and slave node 30A—30C consist of multiple VLANs (Virtual

Connected by Local Area Network. Between master node 20A and slave node 30A, VLAN1, which is a counterclockwise communication path (hereinafter referred to as a forward path) as viewed from master node 20A on ring network 90, and a clockwise communication path VLAN 11 is set as a pair of VLANs (hereinafter referred to as reverse path).

[0023] Further, between the master node 20A and the slave node 30B, VLAN2 that is a forward path and VLAN12 that is a reverse path are set as a pair of VLANs. In addition, between the master node 20A and the slave node 30C, VLAN3, which is a forward route, and a reverse route are used. VLAN 13 is set as a set of VLANs.

In the first embodiment, in the communication between master node 20A and slave node 30A, one of VLAN 1 and VLAN 11 set between master node 20A and slave node 30A is used as the working VLAN. Use as A VLAN that is different from the working VLAN is used as needed. For example, VLAN 1 is the working VLAN and VLAN 11 is the backup VLAN. As with VLAN1 and VLAN11, one of VLAN2 and VLAN12, VLAN3 and VLAN13 is the working VLAN, and the other is the backup VLAN. For the master node 20A and slave nodes 30A-3C, a working VLAN and a spare VLAN are set in advance.

Next, the configuration of the master node 20A and slave nodes 30A-30C will be described.

Note that the slave nodes 30A-30C have the same configuration, and therefore, description will be given here taking the slave node 30A as an example.

FIG. 3 is a block diagram showing a configuration of the master node according to the first embodiment. Master node 20A has forward port 21, reverse port 22, switch unit 23, tag processing unit (change instruction unit) 24, VLAN processing unit 25, upper network communication unit 27, connection determination unit (failure detection unit). 28 and control unit 29.

The forward-side port 21 is a port for transmitting / receiving information to / from the slave nodes 30A-30C by the VLAN1-3 connected to the forward side in the network system. The reverse side port 22 is a port for transmitting / receiving information to / from the slave nodes 30A-30C by the VLA N 11-13 connected to the reverse side in the network system.

[0028] The VLAN processing unit 25 sets a port for each node, a VLAN corresponding to the port, and the like, and determines a VLAN to be used in the network system based on the set information.

Based on the instruction information from the VLAN processing unit 25, the switch unit 23 switches the ports (forward direction port 21 and reverse direction port 22) that perform communication. When the switch unit 23 communicates with the slave nodes 30A-30C, the switch unit 23 switches between the forward port 21 and the reverse port 22 for each slave node 30A-30C.

[0030] The Tag processing unit 24 uses a MAC frame when communicating between nodes in the network system. Add (add) or delete the VLAN tag described below to the group. The upper network communication unit 27 communicates with the upper network 201A.

[0031] The connection determination unit 28 determines whether or not a link lower layer disconnection state (link disconnection) has occurred in the network system. The connection determination unit 28 creates predetermined information for detecting a failure with respect to adjacent nodes in the ring network 90 and transmits / receives them to / from the forward direction port 21 and the backward direction port 22. For example, when it becomes impossible to receive information (such as a lower layer monitoring frame described later) from the connected slave node, the connection determining unit 28 determines that a failure has occurred (link disconnection).

The control unit 29 controls the forward port 21, the reverse port 22, the switch unit 23, the tag processing unit 24, the VLAN processing unit 25, the upper network communication unit 27, and the connection determination unit 28.

FIG. 4 is a block diagram showing a configuration of the slave node according to the first embodiment. The slave node 30A includes a forward port 21, a reverse port 22, a switch unit 23, a tag processing unit 24, a VLAN processing unit 25, a connection determination unit 28, a lower network communication unit 32, and a control unit 29.

[0034] Lower network communication unit 32 communicates with lower network 301A. The VLAN processing unit 25 of the slave node 30A sets a port included in the slave node 30A, a VLAN (VLAN table 86A described later) corresponding to the port, and the like, and uses it in the network system based on the set information. Determine the VLAN.

Next, the operation procedure of the network system will be described. Since slave node 3 OA-30C performs the same operation, a case where slave node 30A transmits and receives information will be described as an example here.

FIG. 5 and FIG. 6 are flowcharts showing a procedure for transmitting and receiving information in the network system. Predetermined settings are made in advance in the nodes in the network system. That is, a node type (master node or slave node) is set for each node. In the first embodiment, one master node 20A and three slave nodes 30A-30C are set for the nodes in the network system!

[0037] Each node is set with the state (blockage, release of blockage) of the port included in each node. Each node also has a failure detection method (link failure detection, VLAN failure detection, Detection error) is set. In the first embodiment, it is set to detect a failure by detecting a broken link.

[0038] The master node 20A in the network system communicates with the slave nodes 30A to 30C based on a preset port state or the like. Each node in the ring network 90 (master node 20A, slave node 30A-30C) communicates with, for example, the current VLAN1-3, and notifies the occurrence of a failure using the spare VLAN 11-13 when a failure occurs. To do.

[0039] The lower network communication unit 32 of the slave node 30A receives the MAC frame 80 from the lower network 301A (step S100). Here, the MAC frame 80 will be described.

FIG. 7 is a diagram showing the structure of the MAC frame. MAC frame 80 is the destination MAC address, source MAC address, Length / Type information, Data FCS (Frame

Check Sequence). The destination MAC address indicates the address of the node that is the transmission destination of the MAC frame 80. The source MAC address indicates the address of its own node that is the source of the MAC frame 80. The LengthZType information indicates the MAC frame 80 packet length and the upper protocol identification field. FCS indicates information for data error detection.

[0041] In the ring network 90, communication is performed using a VLAN tag. That is, when the master node 20A and the slave nodes 30A-30C in the ring network 90 receive the MAC frame 80 from the upper network 201A and the lower networks 301A-301C, a VLAN tag is assigned to this MAC frame. The MAC frame 80 with the VLAN tag added was transferred within the ring network 90, and was assigned when the MAC frame 80 was transmitted outside the ring network 90 (upper network 201A, lower network 301A 301C). Delete VLAN-Tag.

[0042] For example, when the lower network communication unit 32 of the slave node 30A receives the MAC frame 80 from the lower network 301A, the Tag processing unit 24 adds the VID (Virtual

VLAN tag 70 is added as information indicating (LAN Identification) and MAC frame 81 (Step SI 10).

FIG. 8 is a diagram showing a configuration of a MAC frame to which one VLAN tag is assigned. The MAC frame 81 is configured by adding a VLAN tag 70, which is information about VLAN, to the MAC frame 80. The VLAN-Tag 70 here includes “Priority” for priority control of communication and “VID” for identifying VLAN. The VLAN set as the working VLAN is identified by the VID of MAC frame 81.

[0044] The LengthZType information of the MAC frame 81 includes LengthZType information indicating that a VLAN tag is attached to this frame! /! The MAC frame 81 to which the VLAN—Tag 70 is assigned is transmitted from the forward port 21 of the slave node 30A to the master node 20A (step S120).

[0045] When the forward port 21 of the master node 20A receives the MAC frame 81 from the slave node 30A, the tag processing unit 24 of the master node 20A generates a MAC frame 80 in which the VLAN—Tag 70 is deleted from the MAC frame 81. (Step S130). The MAC frame 80 generated by the tag processing unit 24 is transmitted from the upper network communication unit 27 to the upper network 201A (step S140).

[0046] When the upper network communication unit 27 of the master node 20A receives the MAC frame 80 from the upper network 201A, the Tag processing unit 24 of the master node 20A generates a MAC frame 81 from the MAC frame 80 (steps S200 and S210). ).

[0047] A MAC frame 80 transmitted to the slave node 30A via VLAN1 is given a VID including information on the working VLA N1. The MAC frame 81 generated by the tag processing unit 24 is transmitted from the forward port 21 to each slave node 30A via VLAN1-3 (step S220). When slave port 30A—forward port 21 of 30C receives MAC frame 81 from master node 2 OA, each tag processing unit 2 4 of slave node 30A—30C deletes the VLAN of MAC frame 81—MAC frame 80 from which MAC tag 80 is deleted. (Step S230). The MAC frame 80 generated by the tag processing unit 24 is transmitted from the lower network communication unit 27 of the slave node 30A to the lower network 301A (step S240).

[0048] Also, whether the lower network communication unit 32 of the slave node 30A is the lower network 301A. When receiving MAC frame 81 with one VLAN — Tag 71 attached, the tag processing unit 24 of the slave node 30A uses the MAC frame 81 as information indicating the VID of the working VLAN 1.

VLAN—Creates MAC frame 82 with Tag 72 attached.

FIG. 9 is a diagram showing a configuration of a MAC frame to which two VLAN tags are assigned. MA

The C frame 82 is configured by adding a VLAN tag 72 to a MAC frame 81 to which one VLAN tag 71 is attached.

[0050] Attached to MAC frame 81 !, if VLAN-Tag is VLAN-Tag71,

The MAC frame 82 contains the original V as the VLAN tag attached to the MAC frame 81.

LAN—Tag 71 is assigned. And the original VLAN—Tag 71 has the original “Priority” and “

VID "is included.

[0051] The VLAN tag 72 attached by the tag processing unit 24 includes "Priority" and "VID". The Length / Type information of the MAC frame 82 shows Length / Type information indicating that a VLAN tag is attached to this frame! The MAC frame 82 to which the VLAN tag 72 is added is transmitted from the forward port 21 of the slave node 30A to the master node 20A via VLA N1.

Thereafter, the same processing as when master node 20A receives MAC frame 81 from slave node 30A is performed. That is, when the forward port 21 of the master node 20A receives the MAC frame 82 from the slave node 30A, the Tag processing unit 24 of the master node 20A generates a MAC frame 81 in which the VLAN tag 72 is deleted from the MAC frame 82. The MAC frame 81 generated by the tag processing unit 24 is transmitted from the upper network communication unit 27 to the upper network 201A.

[0053] When the upper network communication unit 27 of the master node 20A receives the MAC frame 81 from the upper network 201A, the Tag processing unit 24 of the master node 20A generates a MAC frame 82 from the MAC frame 81.

[0054] A MAC frame 80 transmitted to the slave node 30A via VLAN1 is given a VID including information on the working VLA N1. The MAC frame 82 generated by the Tag processing unit 24 is transmitted from the forward port 21 to the slave node 30A via VLAN1. Slave node 30A forward port 21 receives MAC frame 82 from master node 20A. Then, each tag processing unit 24 of the slave node 30A generates a MAC frame 81 from which the VLAN tag 72 of the MAC frame 82 is deleted. The MAC frame 81 generated by the tag processing unit 24 is transmitted from the lower network communication unit 32 of the slave node 30A to the lower network 301A.

Next, a procedure for detecting a failure in the ring network 90 will be described. The master node 20A in the network system detects a fault in the network system based on a preset fault detection method. In addition, since the Tagawa page of failure detection between the nodes is performed by the same Tagawa page, here, the failure detection between the slave node 30A and the slave node 30B will be described as an example.

FIG. 10 is a flowchart showing a failure detection procedure according to the first embodiment. In order to detect (monitor) the occurrence of a fault in the ring network 90, a lower layer monitoring frame for monitoring a lower layer between nodes (master node 20A, slave node 30A-30C) in the ring network 90 is provided. Send and receive. In the first embodiment, the slave node 30A periodically transmits and receives lower layer monitoring frames to and from the master node 20A and slave node 30B adjacent to the slave node 30A, and the slave node 30C is a slave adjacent to the slave node 30C. The node 30B periodically transmits and receives lower layer monitoring frames (step S300).

For example, when a lower layer link disconnection (failure) occurs between the slave node 30A and the slave node 30B, reception of the lower layer monitoring frame between the slave node 30A and the slave node 30B is interrupted (step S305).

[0058] The slave node 30A cannot receive the lower layer monitoring frame transmitted from the slave node 30B. Therefore, the slave node 30A is linked via the port on the VLAN 11 side (reverse port 22) on the slave node 30B side. Is detected to be in a disconnected state (link disconnected) (occurrence of failure) (step S310). Here, the connection determination unit 28 determines whether or not the link is broken. That is, the connection determination unit 28 of the slave node 30A determines that the link is broken (proximity link disconnection) when the lower layer monitoring frame from the slave node 30B cannot be received by the reverse direction side port 22.

[0059] Further, the slave node 30B transmits the lower layer monitoring frame transmitted from the slave node 30A. Since the frame cannot be received, it is detected that the link is broken via the VLAN 2 side port (forward side port 21) which is the slave node 30A side port (step S315). That is, when the connection determination unit 28 of the slave node 30B cannot receive the lower layer monitoring frame from the slave node 30A by the forward port 21, it determines that the adjacent link is disconnected.

[0060] When the connection determination unit 28 of the slave node 30A determines that the proximity link is broken, the switch unit 23 is switched based on the instruction information from the VLAN processing unit 25, and the port that detected the failure (reverse) A MAC frame (hereinafter referred to as link disconnection notification) indicating a close link disconnection is transmitted from the VLAN1 side port (forward port 21), which is the opposite port to the direction side port 22) (step). S320).

[0061] When the connection determination unit 28 of the slave node 30B determines that the proximity link is broken, the switch unit 23 is switched based on the instruction information from the VLAN processing unit 25, and a failure occurs. A link disconnection notification indicating a close link disconnection is transmitted from the port on the VLAN 12 side (reverse port 22) that is the opposite port to the port that detected the port (forward port 21) (step S330). .

[0062] In the ring network 90, the slave node and the master node other than the ring end node that has received the link disconnection notification transmit the link disconnection notification from the port opposite to the port that has received the link disconnection notification. In other words, the slave node or master node that has received the link disconnection notification from the forward port 21 transmits the link disconnection notification from the reverse port 22. On the other hand, the slave node or master node that has received the link disconnection notification from the reverse port 22 transmits the link disconnection notification from the forward port 21. In the ring network 90, the slave node and the master node, which are ring end nodes that have received the link disconnection notification, terminate the link disconnection notification, and therefore do not transfer the link disconnection notification.

Here, the slave node 30C receives the link disconnection notification from the slave node 30B through the VLAN3 side port (j injection direction side port 21). When the connection determination unit 28 of the slave node 30C receives the link disconnection notification, it determines (detects) that the link different from the node connected to its own node is the link disconnection (remote link disconnection) (step). S340). Since the slave node 30C here is a ring-end node, the link failure notification from the slave node 30B is sent. Terminate and do not send link disconnection notification to VLAN13.

[0064] Further, the master node 20A receives the link disconnection notification from the slave node 30A via the VLAN1 side port (forward direction side port 21). When receiving the link disconnection notification, the connection determination unit 28 of the master node 20A determines that the remote link is disconnected (step S350). Since the master node 20A is a ring end node, the link disconnection notification from the slave node 30A is terminated and the link disconnection notification is not transmitted to the VLAN 11.

[0065] In the first embodiment, the power described in the case where the master node in the ring network 90 is one of the master nodes 20A may be configured such that the ring network 90 includes a plurality of master nodes. Yo ...

FIG. 11 is a diagram showing a configuration of a network system having a plurality of master nodes, and FIG. 12 is a diagram showing a VLAN configuration of a network system having a plurality of master nodes. Among the components shown in FIGS. 11 and 12, the components that achieve the same functions as those of the network system and VLAN shown in FIGS. 1 and 2 are given the same numbers, and redundant description is omitted.

[0067] The ring network 90 of the network system here includes the master nodes 20A and 20B and the slave nodes 30A and 30B. The master node 20B has the same function as the master node 20A.

Master nodes 20A and 20B and slave nodes 30A and 30B are connected in a ring shape. Slave node 30A is connected to master node 20A and slave node 30B, and master node 2OB is connected to master node 20A and slave node 30B.

[0069] Here, in order to make the ring network 90 an open loop, the ports on both ends of the link connecting the master node 20A and the master node 20B (the master node 20B side port in the master node 20A, the master node 20A in the master node 20B) The side port) is logically blocked (master node 20A and master node 20B are connected by blocked link 55). That is, it becomes the ring end node of the master node 20A and the master node 20B force blocking link 55.

The master node 20A is connected to the upper network 201A, and the master node 20B is connected to the upper network 201B. Between master node 20A and slave node 30A Is configured with VLAN1, which is a forward path when viewed from the master node 20A on the network system. In addition, VLAN2 which is a forward path is set between the master node 20A and the slave node 30B!

[0071] Between the master node 20B and the slave node 30A, a VLAN 61 is set which is a reverse path (counterclockwise) in view of the master node 20B force on the network system. Further, a VLAN 62 which is a reverse path is set between the master node 20B and the slave node 30B.

[0072] Between the master node 20A and the master node 20B, a VLAN 51 that is a forward path and a VLAN 75 that is a reverse path as set by the master node 20A on the network system are set as a pair of VLANs. . VLANs 51 and 75 between the master node 20A and the master node 20B are VLANs (management VLANs) used for managing communication in the network system.

[0073] Even in a network system having a plurality of master nodes, failure detection is performed by a procedure similar to the procedure shown in the flowchart of FIG. That is, for example, when a failure occurs between the slave node 30A and the slave node 30B, the slave node 30A cannot receive the lower layer monitoring frame to which the slave node 30B force is transmitted, so the slave node 30B is a port on the slave node 30B side. Detects that the link is broken through the VLAN 61 port.

[0074] In addition, the slave node 30B cannot receive the lower layer monitoring frame transmitted by the slave node 30A. Therefore, the link must be disconnected via the port of VLAN 2 that is the port on the slave node 30A side. Is detected.

[0075] When the connection determination unit 28 of the slave node 30A determines that the proximity link is disconnected, the slave node 30A disconnects the proximity link from the port on the VLAN 1 side that is the port opposite to the port where the failure is detected. A link disconnection notification indicating that there is a message is transmitted.

[0076] When the connection determination unit 28 of the slave node 30B determines that the adjacent link is disconnected, the slave node 30B disconnects the adjacent link from the port on the VLAN 62 side that is the opposite port to the port where the failure is detected. A link disconnection notification indicating that is is transmitted.

[0077] The master node 20B is a slave node by a port on the VLAN3 side (port 21 on the jet direction side). Receive a 30B link break notification. When the connection determination unit 28 of the master node 20B receives the link disconnection notification, it determines that the remote link is disconnected. Since the master node 20B here is a ring end node, the link disconnection notification from the slave node 30B is terminated and the link disconnection notification is not sent to the VLAN 75 !.

In addition, the master node 20A receives the link disconnection notification from the slave node 30A via the VLAN 1 side port (forward direction side port 21). The connection determination unit 28 of the master node 20A determines that the remote link is disconnected when the link disconnection notification is received. Since the master node 20A is a ring end node, the link disconnection notification from the slave node 30A is terminated and the link disconnection notification is not transmitted to the VLAN 61 !.

[0079] In the first embodiment, one or four force ring networks 90 described in the case where the ring network 90 force is configured by two or three slave nodes and one or two master nodes are used. It may consist of more than two slave nodes and more than two master nodes.

In the first embodiment, the master node 20A transmits / receives information to / from the upper network 201A, and the slave nodes 30A-30C transmit / receive information to / from the lower networks 301A-301C. Master node 20A The slave nodes 30A-30C may be capable of transmitting / receiving information to / from the upper network 201 and the lower networks 301A-301C. That is, both the master node 20A and the slave nodes 30A-30C include the upper network communication unit 27 and the lower network communication unit 32, and either the upper network communication unit 27 or the lower network communication unit 32 as necessary. It may be a configuration that selects whether to use.

As described above, according to the first embodiment, since the occurrence of a failure is monitored by periodically transmitting and receiving lower layer monitoring frames between all the nodes in the ring network 90, the lower layer link It is possible to detect the close link of layer 2 due to the disconnection for each node. In addition, the node in the ring network 90 that has detected the proximity link disconnection transmits a link disconnection notification from the port opposite to the port that has detected the proximity link, and the node that has received the link disconnection notification transmits the ring disconnection notification. Since the ring break notification is forwarded to a node different from the transmitting node, all nodes in the ring network 90 can quickly detect a failure between the nodes. It becomes ability.

[0082] Embodiment 2.

A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the transmission quality of the lower layer at each port of the node in the ring network 90 is periodically monitored, and link breakage is detected based on the transmission quality of data received from the port.

A failure detection procedure according to the second embodiment will be described. It should be noted that the failure detection procedure between the nodes is performed in the same manner, and here, the failure detection between the slave node 30A and the slave node 30B will be described as an example.

FIG. 13 is a flowchart showing a failure detection procedure according to the second embodiment. The connection judgment unit 28 periodically monitors the lower layer transmission quality at each port of the nodes in the ring network 90 (master node 20A, slave nodes 30A-30C) (step S400).

[0085] For example, when the transmission quality between the slave node 30A and the slave node 30B falls below a predetermined threshold (decrease in transmission quality), the connection determination unit 28 of the slave node 30A is based on data reception by the port on the VLAN 11 side. Layer 2 link disconnection (proximity link disconnection) is detected (steps S405 and S410). The close link disconnection here includes the case where the quality of the lower layer link is unstable and the quality deteriorates to such an extent that the link will not be disconnected (decrease in transmission quality).

[0086] When the transmission quality between the slave node 30A and the slave node 30B falls below a predetermined threshold, the connection determination unit 28 of the slave node 30B is based on data reception by the port on the VLAN2 side! /, Layer 2 neighboring link disconnection is detected (step S415).

[0087] Hereinafter, similarly to the link disconnection notification in the first embodiment, the node in the ring network 90 is notified of link disconnection due to quality deterioration (hereinafter referred to as quality deterioration notification). In other words, the slave node 30A transmits a quality degradation notification from the port on the VLAN 1 side (forward port 21) that is the opposite port to the port (reverse port 22) that detected the link break (step S420).

) o

[0088] In addition, the slave node 30B sends a quality degradation notification from the port on the VLAN 12 side (reverse port 22) that is the opposite port to the port (forward port 21) that detected the link break. (Step S430)

[0089] The slave node 30C receives the quality degradation notification of the slave node 30B through the VLAN3 side port (j jet direction side port 21), and the connection determination unit 28 of the slave node 30C determines that the remote link is disconnected. (Step S440).

[0090] Further, the master node 20A receives the quality degradation notification from the slave node 30A through the port on the VLAN 1 side (forward direction port 21), and the connection determination unit 28 of the master node 20A indicates that the remote link is disconnected. Judgment is made (step S450).

[0091] Since master node 20A and slave node 30C are ring-end nodes, slave node 3

Terminate the quality degradation notification from the OA and do not send the link disconnection notification to VLAN13 and VLAN11.

[0092] In the second embodiment, the force described for the case where the master node in the ring network 90 is one of the master nodes 20A is also illustrated in the case where the ring network 90 is configured by a plurality of master nodes. Since the failure detection is performed by the same procedure as shown in the flowchart of FIG.

As described above, according to the second embodiment, since the occurrence of a failure is monitored by periodically monitoring the transmission quality of the lower layer in each node in the ring network 90, the link of the lower layer is Even if the quality deteriorates to such an extent that it is unstable and does not cause a link break, it is possible to detect a layer 2 close link break. In addition, the node in the ring network 90 that detected the close link disconnection transmits a quality deterioration notification from the port on the opposite side to the port that detected the close link, and the node that received the quality deterioration notification transmits the quality deterioration notification. Since the quality deterioration notification is transferred to a node different from the above node, all the nodes in the ring network 90 can quickly detect the deterioration of the transmission quality between the nodes.

[0094] Embodiment 3.

A third embodiment of the present invention will be described with reference to FIG. 2, FIG. 12, and FIG. In this third embodiment, a fault is detected by monitoring VLANs between all VLA N termination points of the master node 20A and slave nodes 30A-30C. In other words, in this third embodiment, the VLAN is monitored by the blocked port in addition to the port that is not blocked. A failure detection procedure according to Embodiment 3 will be described. The failure detection procedure between each node is performed in the same way when a failure occurs between any of the nodes, so here we explain the case where a failure occurs between slave node 30A and slave node 30B as an example. To do.

FIG. 14 is a flowchart showing a failure detection procedure according to the third embodiment. The VLANs of the master node 20A and slave nodes 30A—30C (all working VLANs and all spare VLANs) shown in Figure 2 are regularly monitored between the end points. Here, a request to monitor a VLAN between VLAN termination points of the ring network 90 (VLAN monitoring request (MAC frame)) and response information (MAC frame) to the VLAN monitoring request (hereinafter referred to as VLAN response information). ) Is periodically sent and received (step S500).

Specifically, VLAN monitoring requests and VLAN response information are transmitted / received between the master node 20A and the slave node 30A through VLANs 1 and 11. In addition, between the master node 20A and the slave node 30B, VLAN monitoring requests and VLAN response information are transmitted and received by VLANs 2 and 12. Further, between the master node 20A and the slave node 30C, VLAN monitoring requests and VLAN response information are transmitted and received by VLANs 3 and 13.

For example, when a failure occurs between slave node 30A and slave node 30B, reception of VLAN monitoring requests and VLAN response information in VLANs 2, 3, and 11 is interrupted (step S505).

[0099] Master node 20A cannot receive VLAN monitoring requests or VLAN response information on VLANs 2 and 3 on the forward path, and therefore receives data from the ports on VLANs 2 and 3 (forward port 2 1). VLAN failure is detected by disruption of The VLAN failure here is a failure in the communication path of the VLAN set in the ring network 90, and if the link is broken, quality degradation or the like is included.

[0100] Master node 20A cannot receive VLAN monitoring requests or VL AN response information on VLAN 11 in the reverse path, so VLAN failure occurs due to data reception interruption at the VLAN 11 side port (reverse side port 22). Is detected (step S510). Here, the connection determination unit 28 of the master node 20A determines whether or not there is a VLAN failure. That is, the connection determination unit 28 of the master node 20A receives the VL from the slave nodes 30B and 30C. If the AN monitoring request and VLAN response information cannot be received on VLANs 2 and 3, it is determined that the VLAN is faulty if the VLAN monitoring request and VLAN response information from slave node 30A cannot be received on VLAN 11.

[0101] In addition, since the slave node 30A cannot receive VLAN monitoring requests or VLAN response information in VLAN11 on the reverse path, VLAN failure occurs due to data reception interruption on the VLAN11 side port (reverse side port 22). Is detected (step S515). Here, the connection determination unit 28 of the slave node 30A determines whether or not there is a VLAN failure. That is, the connection determination unit 28 of the slave node 30A determines that a VLAN failure has occurred when the VLAN 11 cannot receive the VLAN monitoring request or the VLAN response information from the slave node 30C.

[0102] In addition, the slave node 30B cannot receive the VLAN monitoring request or the VLAN response information on the VLAN 2 on the forward path, so the data reception by the port on the VLAN 2 side (forward side port 21) is interrupted. To detect a VLAN failure (step S520). In the slave node 30B, the connection determination unit 28 determines whether there is a VLAN failure. In other words, the connection determination unit 28 of the slave node 30B determines that a VLAN failure has occurred when the VLAN monitoring request or VLAN response information from the master node 20A cannot be received by VLAN2.

[0103] In addition, since the slave node 30C cannot receive the VLAN monitoring request or the VLAN response information on the VLAN 3 in the forward path, the data reception by the VLAN 3 side port (forward side port 21) is interrupted. To detect a VLAN failure (step S525). In the slave node 30C, the connection determination unit 28 determines whether or not it is a VLAN failure. That is, the connection determination unit 28 of the slave node 30C determines that a VLAN failure has occurred when the VLAN monitoring request or VLAN response information from the master node 20A cannot be received by VLAN3.

[0104] Note that the third embodiment is a case where the ring network 90 is configured by a plurality of master nodes as described in the case where the master node in the ring network 90 is one of the master nodes 20A. However, failure detection is performed by the same procedure as shown in the flowchart of FIG. That is, the master node 20A and the master node 20B Fault detection is performed by sending and receiving VLAN monitoring requests and VLAN response information between the end points of the management VLAN and backup VLAN between the host nodes. Specifically, the VLAN monitoring request and the VLAN response information are transmitted / received between the master node 20A and the slave nodes 30A and 30B through VLAN1 and 61. In addition, the VLAN monitoring request and the VLAN response information are transmitted / received between the master node 20B, the slave node, and the slave nodes 30A and 30B through VLANs 2 and 62. Further, the VLAN monitoring request and the VLAN response information are transmitted / received between the master node 20A and the master node 20B by the VLANs 51 and 71.

Thus, according to the third embodiment, VLAN monitoring requests and VLAN response information are periodically transmitted and received between the termination points of the VLAN between the master node 20A and the slave nodes 30A-30C. Since the occurrence of a failure is monitored, it is possible to monitor the failure between each VLAN of the combination of the master node and the slave node. In addition, since each node in the ring network 90 detects a VLAN failure, all the nodes in the ring network 90 can quickly detect the occurrence of a failure between the nodes without notifying the occurrence of the failure between the nodes. It becomes possible.

[0106] Embodiment 4.

A fourth embodiment of the present invention will be described with reference to FIG. 2, FIG. 12, FIG. 15 to FIG. In the fourth embodiment, the master node 20A transmits a ring monitoring request for detecting a failure to the ring end node and receives VLAN response information from the ring end node. The master node 20A detects the occurrence of a failure based on the identification information of the ring end node that transmits the VLAN response information.

FIG. 15 is a block diagram showing the configuration of the master node according to the fourth embodiment. Of the components shown in FIG. 15, the same function as the master node according to the first embodiment shown in FIG. 3 is achieved. The same number is attached | subjected about the component to perform, and the overlapping description is abbreviate | omitted.

The master node 20A includes a storage unit 26 in addition to a forward port 21, a reverse port 22, a switch unit 23, a tag processing unit 24, an upper network communication unit 27, a connection determination unit 28, and a control unit 29. I have.

[0109] The storage unit 26 stores the VID related to the VLAN added to the response information from the ring end node. The connection determination unit 28 is based on the VLAN-related VID stored in the storage unit 26. It is determined whether or not a failure has occurred between nodes. Based on the topology information 87A, the connection determination unit 28 determines whether or not a failure has occurred between the shifted nodes.

Next, the failure detection procedure according to Embodiment 4 will be described. Note that the failure detection procedure between each node is performed in the same way when a failure occurs between any of the nodes, so here we explain the case where a failure occurs between slave node 30A and slave node 30B as an example. To do.

FIG. 16 and FIG. 17 are flowcharts showing the procedure of fault detection according to the fourth embodiment.

In the storage unit 26 of the master node 20A, topology information 87A is stored in advance as information on the topology in the network system.

FIG. 18 is a diagram showing a configuration of topology information set in the master node. Topology Information 87A consists of port P1 (forward port 21) on the forward path side of master node 20A and slave node 30A-30C in ring network 90, port P2 on the reverse side (reverse port 22). ) Also provides information regarding the state of blockage. Here, port P1 of the master node 20A is released from blocking, and port P2 is blocked. In addition, the ports PI and P2 of the slave nodes 30A and 30B are shown to be blocked. In addition, it indicates that port P1 of slave node 30C has been unblocked and port P2 is blocked!

[0113] VLAN monitoring is periodically performed between the master node 20A and the ring end node shown in FIG. Here, the ring monitoring request (MAC frame) and the ring response information (MAC frame) are periodically transmitted and received on the forward path and the reverse path between the master node 20A and the slave node 30C.

Specifically, ring monitoring request and ring response information are transmitted and received on the forward path between master node 20A and slave node 30C. In addition, a ring monitoring request and ring response information are transmitted and received on the reverse path between the master node 20A and the slave node 3OC. Here, first, a ring monitoring request is transmitted to the slave node 30C through the master node 20A force forward path and reverse path (step S600).

[0115] When the slave node other than the ring end node receives the ring monitoring request or response information, the ring monitoring request or response information is transferred from the port opposite to the received port. Example For example, when a slave node other than the ring end node receives a ring monitoring request from the forward port 21, the ring monitoring request is transmitted (transferred) from the reverse port 22 as a port opposite to the forward port 21.

[0116] For example, when the master node 20A transmits a ring monitoring request from the forward path to the slave node 30C, the slave nodes 30A and 30B are not ring-end nodes, so the ring monitoring requests from the master node 20A are forwarded. Transfer to slave node 30C on the direction path side (step S610).

[0117] When the tag processing unit 24 of the slave node 30C that is the ring end node receives the ring monitoring request from the forward path (VLAN3 side) (step S620), the VLAN on the forward path side that has received the ring monitoring request Create ring response information with VID related to VLAN3 added to the ring monitoring request.

[0118] The ring response information created by the tag processing unit 24 of the slave node 30C is transmitted to the master node 20A from which the ring monitoring request has been transmitted (step S630). For example, when the master node 20A receives a ring monitoring request from the forward path to the slave node 30C, the slave node 30C also transmits ring response information to the master node 20A in the forward path force. Since the slave nodes 30A and 30B are not ring ends, the ring response information of the slave node 30C is transferred to the master node 20A.

The master node 20A stores the VID related to VLA N3 attached to the ring response information from the slave node 30C in the storage unit 26 (step S640). In this state, for example, when a failure occurs between the slave node 30A and the slave node 30B, the slave node 3OA and the slave node 30B become ring end nodes (step S700). A ring monitoring request is transmitted from the master node 20A along the forward path (step S710).

[0120] When the tag processing unit 24 of the slave node 30A, which is the ring end node, also receives the ring monitoring request (forward direction path side (VLAN1 side) force) (step S720), the forward path that has received the ring monitoring request. The ring response information is created by adding the VID related to VLAN 1 set in the side VLAN to the ring monitoring request.

[0121] The ring response information created by the tag processing unit 24 of the slave node 30C is transmitted to the forward path (VLAN1) from which the ring monitoring request has been transmitted (step S730). The master node 20A stores the VID related to VLANl attached to the ring response information from the slave node 30C in the storage unit 26 (step S740).

[0122] The connection determination unit 28 of the master node 20A determines whether or not a failure has occurred between the nodes based on the VID stored in the storage unit 26. The master node 20A before the failure occurs between the slave node 30A and the slave node 30B receives the VID related to VLAN3 and stores it in the storage unit 26 as well. On the other hand, the master node 20A after the failure between the slave node 30A and the slave node 30B receives the VID related to VLAN1 from the slave node 30A and stores it in the storage unit 26. Therefore, the connection determination unit 28 of the master node 20A determines that the ring end node has been changed because the VID of the response information for the ring monitoring request stored in the storage unit 26 has changed. In other words, the connection determination unit 28 determines that the ring end node has been changed due to the occurrence of a failure between the nodes (step S750). In addition, the connection determination unit 28 specifies whether a failure has occurred between the V and misaligned nodes based on the topology information 87A stored in the storage unit 26.

[0123] Master node 20A has slave node 30A and slave node 30B based on the fact that VID related to VLAN1 is added to the VLAN response information for the ring monitoring request transmitted on the forward path (VLAN1) and topology information 87A. Detects that a failure occurred during

[0124] The fourth embodiment is a case where the ring network 90 is configured by a plurality of master nodes as described in the case where the master node in the ring network 90 is one of the master nodes 20A. May be. In this case, set one of the multiple master nodes to operate as a master node and the other master nodes to operate as slave nodes. The VID related to the management VLAN is added to the ring monitoring request and ring response information between the master nodes and transmitted.

As described above, according to the fourth embodiment, the occurrence of a failure between nodes is monitored by transmitting and receiving the ring monitoring request and response information only between the master node 20A and the ring end node. As a result, the master node 20A can quickly detect a failure between nodes.

[0126] Embodiment 5. A fifth embodiment of the present invention will be described with reference to FIGS. In the fifth embodiment, after the master node 20A and slave nodes 30A-30C detect the occurrence of a failure by receiving the link disconnection notification and the quality degradation notification, each node switches the VLAN setting. In the fifth embodiment, the VLAN processing unit 25 changes the VLAN setting or the like based on the determination result of the failure occurrence capability determined by the connection determination unit 28. Instruction information is sent to the switch unit 23 so that communication is performed using the VLAN determined by the VLAN processing unit 25 of each node.

A procedure for switching VLANs after failure detection according to the fifth embodiment will be described. Here, an example will be described in which the VLAN setting is changed after a failure is detected between slave node 30A and slave node 30B in the network system shown in FIG.

FIG. 19 is a flowchart showing a procedure for switching VLANs after failure detection according to the fifth embodiment. In the fifth embodiment, the VLAN table 85A indicating the VLAN for each of the slave nodes 30A-30C in advance to the master node 20A and the use (setting) state (active or spare power) of this VLAN, etc. Is set in advance.

[0129] In addition, VLAN tables 86A to 86C are set in the slave nodes 30A to 30C. The VLAN tables 86A to 86C indicate the VLANs for the ports of the slave nodes 30A to 30C, the use state of the VLANs, the state related to blockage of the ports, and the like.

[0130] Also, in the master node 20A and slave nodes 30A-30C, the type of switching method (distributed switching, centralized switching) when switching VLANs is set in advance. In the fifth embodiment, distributed switching in which each node switches the VLAN setting is set in advance.

FIG. 20 is a diagram showing a configuration of VLAN table information set in the master node. The VLAN table information 85A includes information related to the slave nodes 30A-30C. Each slave node 30A-30C has port P1 and port P2. Here, the port P1 indicates the forward port 21 and the port P2 indicates the reverse port 22. That is, the port P1 is set to be connected to the master node 20A by the forward path, and the port P2 is set to be connected to the master node 20A by the reverse path.

[0132] In addition, the ports Pl and P2 of each slave node 30A-30C have VLAN1-3, 11-13 set in the ring network 90 and information on whether this VLAN is active or spare. Information is associated. Here, VLAN table information 85A is shown when VLAN1-3 is set as the working VLAN and VLAN11-13 is set as the backup VLAN in the network system. In the network system, the ports at both ends of the link between the master node 20A and the slave node 30C are blocked and set to open loop.

FIG. 21 to FIG. 23 are diagrams showing the configuration of the VLAN table information set in the slave node. As shown in FIG. 21, the VLAN table information 86A set in the slave node 30A includes information related to the port Pl and the port P2. Here, port P1 indicates that it is associated with the working VLAN 1, and port P2 indicates that it is associated with the spare VLAN 11. In addition, the port Pl associated with VLAN1 and the port P2 associated with VLAN11 are blocked, indicating that they are in a blocked release state.

As shown in FIG. 22, the VLAN table information 86B set in the slave node 30B includes information regarding the port Pl and the port P2. The port P1 here indicates that it is associated with the working VLAN 2, and the port P2 indicates that it is associated with the spare VLAN 12. Also, indicate that port Pl associated with VLAN2 and port P2 associated with VLAN12 are blocked, indicating that they are in a blocked release state! /

[0135] As shown in FIG. 23, the VLAN table information 86C set in the slave node 30C includes information on the port Pl and the port P2. Here, port P1 indicates that it is associated with the working VLAN 3, and port P2 indicates that it is associated with the spare VLAN 13. In addition, it indicates that the port P1 associated with VLAN 3 is in an unblocked state where the port P1 is not blocked, and indicates that the port P2 associated with VLAN 13 is blocked.

For example, as described in the first embodiment and the second embodiment, the master node 20A force VLA N1, 2, 3 forward side port 21 receives the link disconnection notification and the quality degradation notification and connects. The judgment unit 28 detects the occurrence of a failure (step S800). Based on the topology information 87A and the like, the connection determination unit 28 of the master node 20A identifies whether a failure has occurred between the misaligned nodes.

[0137] Here, the slave node 30A that is the transmission source of the link disconnection notification and the master node 20A As a result, it is specified that the port between the slave node 30B on the forward side is blocked (step S810). That is, the connection determination unit 28 of the master node 20A determines that a failure has occurred between the slave node 30A and the slave node 30B. Thereby, the connection determination unit 28 of the master node 20A determines to release the blocking of the blocking link 55 between the master node 20A and the slave node 30C. The VLAN processing unit 25 changes (updates) the previously set topology information 87A to new topology information 87X (step S820).

FIG. 24 is a diagram showing a configuration of topology information whose settings have been changed to the master node. As shown in FIG. 18, in the topology information 87X, the closed state is changed from the topology information 87A. In the master node 20A, the blocking state of the port P2, which is the reverse side port 22, has been changed from blocking to releasing blocking in order to release the blocking of the link with the slave node 30C. In the slave node 30C, the closed state of the port P2, which is the reverse-side port 22, is changed from blocked to unblocked in order to release the closed link with the master node 20A.

[0139] Further, since it is determined by the connection determination unit 28 that a disconnection has occurred between the slave node 30A and the slave node 30B, the slave node 30A is connected to the slave node 30B. The blocking state of port P2, which is the reverse side port 22, has been changed from blocking to blocking. In the slave node 30B, the blocked state of the port P1, which is the forward-side port 21 connected to the slave node 30A, is changed from blocked release to blocked.

[0140] The VLAN processing unit 25 of the master node 20A identifies the faulted VLAN based on the changed topology information 87X and the VLAN table information 85A that is preset in the VLAN processing unit 25! (Step S830). Here, since a failure has occurred between slave node 30A and slave node 30B, and VLAN2 and VLAN3 are working VLANs, it is determined that the failed working VLANs are VLAN2 and VLAN3.

[0141] When the VLAN processing unit 25 of the master node 20A receives the link disconnection notification of the close link disconnection via the port P1 from the VLAN 1 (the connection determination unit 28 detects a failure), the VLAN processing unit 25 performs a VLAN switching process (step S840). Here, VLAN2 is the working VLAN, and the adjacent link or remote link is disconnected by the ports P2 and 3 on the opposite side VLANs 12 and 13 on the opposite side of VLAN2 and 3. Since the link disconnection notification is not received, VLAN processing unit 25 switches the settings of VLAN 2 and 3 to the reserved VLAN. That is, the VLAN processing unit 25 of the master node 20A switches the VLAN settings so that VLANs 2 and 3 are reserved VLANs and VLANs 12 and 13 are active VLANs. Also, release the blocking status of port P2 of master node 20A.

[0142] The VLAN processing unit 25 of the master node 20A changes the VLAN table information 85A according to the VLAN switching processing for each slave node, and sets new VLAN table information 85X.

[0143] The VLAN processing unit 25 of the slave node 30A performs VLAN switching processing according to the VLAN that has received the link disconnection notification of the proximity link disconnection (step S850). Here, since VLAN 11 is a spare VLAN, the VLAN processing unit 25 of the slave node 30A does not perform the VLAN switching process and closes the blocked state of the port P2.

[0144] The VLAN processing unit 25 of the slave node 30A changes the VLAN table information 86A according to the VLAN switching processing or the port blocking state change, and sets new VLAN table information 86X.

[0145] When the VLAN processing unit 25 of the slave node 30B receives the link disconnection notification indicating the close link disconnection via the port P1 from the VLAN 2, it performs the VLAN switching process (step S860). In this example, VLAN 2 is the working VLAN, and the VLAN P 25 has not set the VLAN 2 because the port P2 on the opposite side of the VLAN 2 has not received a link disconnection notification indicating a close link disconnection or remote link disconnection. Switch to spare VLAN. That is, the VLAN processing unit 25 of the slave node 30B switches the VLAN setting so that VLAN 2 is a spare VLAN and VLAN 12 is a working VLAN. Also, block port P1 of slave node 30B.

[0146] The VLAN processing unit 25 of the slave node 30B changes the VLAN table information 86B according to the VLAN switching processing or the change of the port blocking state, and sets new VLAN table information 86Y.

[0147] When the VLAN processing unit 25 of the slave node 30C receives a link disconnection notification indicating that the remote link is disconnected from the port P1, the VLAN processing unit 25 performs a VLAN switching process (step S870). Here, VLAN 3 is the working VLAN, and the backup VLAN 13 side opposite VLAN 3 side. Since the link disconnection notification indicating the proximity link disconnection or the remote link disconnection is not received by the port P2, the VLAN processing unit 25 switches the VLAN3 setting to the spare VLAN. That is, the VLAN processing unit 25 of the slave node 30C switches the VLAN setting so that VLAN 3 is a spare VLAN and VLAN 13 is a working VLAN. Also, release the blocking status of port P2 of slave node 30C.

[0148] The VLAN processing unit 25 of the slave node 30C changes the VLAN table information 86C and sets new VLAN table information 86Z according to the VLAN switching processing or the change of the port blocking state.

FIG. 25 to FIG. 27 are diagrams showing the configuration of VLAN table information whose settings have been changed to slave nodes. As shown in Figure 25, because the VLAN table information 86X whose settings have been changed on the slave node 30A has failed between the slave nodes 30A and 30B, the port P2 of VLAN 11 in the VLAN table information 86X The occlusion state has been changed from occlusion release to occlusion.

The VLAN table information shown in FIG. 26 is the VLAN table information 86Y whose setting has been changed in the slave node 30B. Since a failure has occurred between slave node 30A and slave node 30B, VLAN processing unit 25 of slave node 30B uses VLAN 2 on forward side port 21 (port P1) connected to slave node 30A as a spare VLAN. Change to. The VLAN processing unit 25 of the slave node 30B is connected to the slave node 30A! At the same time, change VLAN 12 on the reverse port 22 (port P2) side to the working VLAN! /. Since a failure has occurred between slave node 30A and slave node 30B, VLAN processing unit 25 of slave node 30B changes the blocking state of port P1 of VLAN 2 connected to slave node 30A to blocking release force blocking. ing.

[0151] The VLAN table information shown in FIG. 27 is the VLAN table information 86Z whose setting has been changed in the slave node 30B. Since a failure has occurred between slave node 30A and slave node 30B, VLAN processing unit 25 of slave node 30C uses VLAN 3 on forward side port 21 (port P1) connected to slave node 30A as a spare VLAN. Change to. Also, the VLAN processing unit 25 of the slave node 30C is connected to the slave node 30A! Change VLAN 13 on the reverse side port 22 (port P2) side to the working VLAN! / . In order to connect the master node 20A and the slave node 30C, the VLAN processing unit 25 of the slave node 30C changes the blocking state of the port P2 of the VLAN 13 connected to the master node 20A to blocking force blocking release.

FIG. 28 is a diagram showing a configuration of VLAN table information whose setting has been changed to the master node. The VLAN table information 85X after the setting change shows the state where the VLAN has been changed in the same manner as each slave node 30A-30C.

That is, since a failure has occurred between slave node 30A and slave node 30B, VLAN 2 on forward side port 21 (port P1) connected to slave node 30A is set as a spare VLAN in slave node 30B. Has been changed. In addition, VLAN 12 on the reverse side port 22 (port P2) side connected to slave node 30A is changed to the working VLAN.

[0154] Further, because a failure has occurred between slave node 30A and slave node 30B, VLAN 3 on the forward port 21 (port P1) side connected to slave node 30A is set as a spare VLAN in slave node 30C. Has been changed. Also, VLAN 13 on the reverse side port 22 (port P2) side connected to slave node 30A is changed to the working VLAN.

FIG. 29 is a diagram showing a configuration after VLAN switching of the network system shown in FIG. Even after the VLAN is changed by each node in the ring network 90, the information is transmitted by the same procedure as the transmission / reception of information in the network system according to the first embodiment shown in FIGS. 51 and 5-2. Send and receive. That is, the lower network communication unit 32 of the slave nodes 30B and 30C receives the MAC frame 80 from the lower networks 301B and 301C.

The tag processing unit 24 of the slave nodes 30B and 30C creates a MAC frame 81 by adding a VLAN-Tag 70 as information indicating the working VLANs 12 and 13 to the MAC frame 80. The MAC frame 81 is transmitted from the reverse side port 22 of the slave node 30A to the master node 20A.

[0157] When the reverse port 22 of the master node 20A receives the MAC frame 81 from the slave nodes 30B and 30C, the tag processing unit 24 of the master node 20A receives the VL from the MAC frame 81. AN — Generates MAC frame 80 with Tag 70 removed. The MAC frame 80 is transmitted from the upper network communication unit 27 to the upper network 201A.

[0158] When the upper network communication unit 27 of the master node 20A receives the MAC frame 80 from the upper network 201A, the Tag processing unit 24 of the master node 20A generates a MAC frame 81 from the MAC frame 80.

[0159] A MAC frame 81 transmitted to the slave nodes 30B and 30C via the VLANs 12 and 13 is assigned a VID including information on the working VLANs 12 and 13. The MAC frame 81 is transmitted from the reverse port 22 to the slave nodes 30B and 30C via the VLANs 12 and 13. When the reverse side port 22 of the slave nodes 30B and 30C receives the MAC frame 81 from the master node 20A, each tag processing unit 24 of the slave nodes 30B and 30C receives the MAC frame 80 from which the VLAN — Tag 70 of the MAC frame 81 has been deleted. Is generated. The MAC frame 80 generated by the tag processing unit 24 is transmitted from the lower network communication unit 27 of the slave nodes 30B and 30C to the lower networks 301B and 30C.

[0160] Further, since master node 20A and slave node 30A transmit and receive information by the same procedure as the transmission and reception of information in the network system according to Embodiment 1, the description thereof is omitted.

As described above, according to the fifth embodiment, each node detects a failure and performs a VLAN switching process. Therefore, when the VLAN in the ring network 90 is switched, the master node 20A becomes the slave node 30A-30C. There is no need to control VLAN switching. Therefore, it is possible to quickly perform the VLAN switching process in the ring network 90, and it is possible to quickly set an alternative route when a failure occurs.

[0162] Embodiment 6.

A sixth embodiment of the present invention will be described with reference to FIGS. In this Embodiment 6, each node switches the VLAN settings after monitoring the VLAN between all the VLAN termination points of the master node 20A and slave nodes 30A-30C and detecting a failure.

A procedure for switching VLANs after failure detection according to the sixth embodiment will be described. Here, the slave nodes 30A and 30B of the network system shown in FIG. An example will be described in which the VLAN setting is changed after a failure is detected.

FIG. 30 is a flowchart showing a procedure for switching VLANs after failure detection according to the sixth embodiment. For example, as described in the third embodiment, VLAN failures in VLANs 2, 3, and 11 are detected by monitoring the master node 20A VLAN (step S900).

[0165] The VLAN processing unit 25 of the master node 20A generates a VLAN failure based on the preset VLAN table information 85A and whether or not response information is transmitted from each node in the ring network 90. The working VLAN is identified (step S910). Here, it is specified that a VLAN failure has occurred in the working VLANs 2 and 3.

[0166] Since the spare VLANs corresponding to the working VLANs 2 and 3 (on the opposite path) are VLANs 12 and 13 and no failure has occurred in VLANs 12 and 13, the VLAN processing unit 25 of the master node 20A is Then, the working VLANs 2 and 3 are set as spare VLANs, and the spare VLANs 12 and 13 are switched to the working VLAN (step S920). The determination of VLAN switching processing by the VLAN processing unit 25 here does not require a port blocking state or topology information.

[0167] The VLAN processing unit 25 of the slave node 30A performs a VLAN switching process according to the VLAN of the port that has received the VLAN failure (step S930). Here, since VLAN 11 is a spare VLAN, VLAN processing unit 25 does not perform VLAN switching processing! /.

[0168] When the VLAN processing unit 25 of the slave node 30B detects a VLAN failure with the working VLAN 2, it will detect the VLAN failure with the protection VLAN 12, so the working VLAN 2 is set as the protection VLAN and the protection VLAN 12 is switched to the working VLAN. (Step S940).

[0169] When the VLAN processing unit 25 of the slave node 30C detects a VLAN failure by the working VLAN 3, it detects that the spare VLAN 13 has failed, so it switches the working VLAN 3 to the working VLAN as the working VLAN 3. (Step S950).

[0170] The VLAN processing unit 25 of the slave nodes 30A-30C changes the VLAN table information 86A-86C according to the VLAN switching process, and sets new VLAN table information 86X-86Z. The VLAN table information 86X-86Z here does not require the port blocking status. When VLAN switching is performed in the network system, the network system is changed to the configuration shown in FIG.

[0171] Thus, according to Embodiment 6, each node detects a failure and performs VLAN switching processing. Therefore, when switching the VLAN in the ring network 90, the master node 20A does not need to control the VLAN switching to the slave nodes 30A-30C. Therefore, it is possible to quickly perform the VLAN switching process in the ring network 90, and it is possible to quickly set an alternative route when a failure occurs.

[0172] In addition, since the occurrence of a failure is monitored 1 between the end points of the VLAN between the master node 20A and the slave nodes 30A-30C, detouring is performed without controlling the port blocking status or topology information. The route can be set quickly.

[0173] Embodiment 7.

A seventh embodiment of the present invention will be described with reference to FIGS. In the present embodiment 7, after the master node 20A detects a close link disconnection, a remote link disconnection, a ring failure, etc., the master node 20A switches the VLAN settings to the slave nodes 30A-30C.

A procedure for switching VLANs after failure detection according to the seventh embodiment will be described. Here, an example will be described in which the VLAN setting is changed after a failure is detected between slave node 30A and slave node 30B in the network system shown in FIG.

FIG. 31 is a flowchart showing a procedure for switching VLANs after failure detection according to the seventh embodiment. The master node 20A is set to centralized switching in which the master node 20A switches the VLAN settings to the slave nodes 30A-30C. For example, as described in the first, second, and fourth embodiments, the master node 20A force VLAN1 forward port 21 and reverse port 22 receive link disconnection notification, quality degradation notification, and ring failure notification. Then, the connection determination unit 28 detects the occurrence of a failure (step S1000).

[0176] The connection determination unit 28 of the master node 20A blocks the port between the slave node 30A that is the transmission source for the link disconnection notification and the like and the slave node 30B that is one forward side as viewed from the master node 20A. (Step S1010). The VLAN processing unit 25 of the master node 20A changes the previously set topology information 87A to new topology information 87X (step S1020).

[0177] The VLAN processing unit 25 of the master node 20A has a failure based on the topology information 87X after the change and the VLAN table information 85A preset in the VLAN processing unit 25! The identified VLAN (VLAN2, 3) is identified (step S1030).

[0178] The VLAN processing unit 25 of the master node 20A indicates that the VLAN 2 is the working VLAN, and the standby VLAN 12 or the link loss notification of the remote link disconnection or the like by the port P2 on the side opposite to the VLANs 2 and 3 VLAN processing unit 25 switches the settings of VLANs 2 and 3 to the spare VLAN. Further, the VLAN processing unit 25 of the master node 20A releases the blocking state of the port P2 that has received the remote link disconnection notification (step S1040).

[0179] The VLAN processing unit 25 of the master node 20A makes a VLAN switch request (switch request request) so that the slave node 30A arranged (connected) next to the master node 20A in the ring network 90 performs the VLAN switch processing. Instruction information (MAC frame)) is transmitted. This VLAN switching request includes instruction information for switching VLAN 1 to the working VLAN and instruction information for blocking port P2 of VLAN 11. VLAN switch requests and VLAN switch responses described later can be sent and received even on blocked ports.

[0180] Slave node 30A receives the VLAN switching request. The slave node 30A performs VLAN switching processing based on the VLAN switching request from the master node 20A (step S1050). Here, the VLAN processing unit 25 of the slave node 30A does not perform the VLAN switching process because VLAN1 is the working VLAN. In addition, the VLAN processing unit 25 of the slave node 30A blocks the port P2 because the port P2 of the VLAN 11 is in the unlocked state. Thereafter, the VLAN processing unit 25 of the slave node 30A transmits a VLAN switching response (MAC frame) indicating that the VLAN switching processing is completed to the master node 20A. Slave node 30A is a ring end node and does not forward the received VLAN switch request.

[0181] The VLAN processing unit 25 of the master node 20A transmits a VLAN switching request to the slave node 30C arranged next to the master node 20A in the ring network 90 through a reverse path. This VLAN switching request includes instruction information for switching VLAN 13 to the working VLAN, and instruction information for releasing port P2 of VLAN 13 from blocking.

[0182] The slave node 30C receives the VLAN switching request. The VLAN processing unit 25 of the slave node 30C performs VLAN switching processing based on the VLAN switching request from the master node 20A (step S1060). Here, VLAN 13 is a spare VLAN Because the neighboring link disconnection or remote link disconnection is not received at port P2 of VLAN13, VLA N13 is switched to the working VLAN. Further, the VLAN processing unit 25 of the slave node 30C releases the blocking of the port P2 because the port P2 of the VLAN 13 is in the blocking state. Thereafter, the VLAN processing unit 25 of the slave node 30C transmits a VLAN switching response indicating that the VLAN switching processing is completed to the master node 20A.

[0183] The VLAN processing unit 25 of the master node 20A transmits a VLAN switching request to the slave node 30B via the slave node 30C and the slave node 30A. In this case, if a link disconnection or the like occurs, a VLAN switching request is transmitted from VLAN 2 to slave node 30B via slave node 30C. This VLAN switching request includes instruction information for switching VLAN 12 to the working VLAN and instruction information for blocking port PI of slave node 30B of VLAN2.

[0184] The slave node 30C receives the VLAN switching request transmitted from the master node 20A to the slave node 30B (step S1070). Here, since it is not a VLAN switching request to its own node, the VLAN switching request is transferred from the port P1 on the opposite side of the port P2 that received this VLAN switching request.

[0185] The slave node 30B receives the VLAN switching request via the slave node 30C. The VLAN processing unit 25 of the slave node 30B switches the VLAN 12 to the working VLAN because the VLAN 12 is a backup VLAN and no close link or remote link disconnection is received at the port P2 of the VLAN 12. In addition, the VLAN processing unit 25 of the slave node 30B blocks the port P1 because the port P1 of the VLAN2 is in the release state. Thereafter, the VLAN processing unit 25 of the slave node 30B transmits a VLAN switching response indicating that the VLAN switching processing is completed to the master node 20A through the reverse path.

[0186] Master node 20A repeats transmission of a VLAN switching request to each slave node 30A-30C for a predetermined time or a predetermined number of times until a VLAN switching response is transmitted from each slave node 30A-30C. .

[0187] The VLAN processing unit 25 of the master node 20A changes the VLAN table information 85A and the topology information 87A according to the VLAN switching processing and the change of the port blocking status, and creates new VLAN table information 85X and topology information 87X. Set. [0188] VLAN processing unit 25 of slave node 30A—30C changes VLAN table information 86A—86C and sets new VLAN table information 86X—86Z according to VLAN switching processing and port blocking status change To do.

As described above, according to the seventh embodiment, the master node 20A can transmit a VLAN switching request to each of the slave nodes 30A-30C. Since each node performs VLAN switching processing based on the VLAN switching request from the master node 20A, it becomes possible to control VLAN switching for each VLAN of the combination of the master node and the slave node. . Therefore, it is possible to quickly set a detour route when a failure occurs between the VLANs of the combination of the master node and the slave node.

[0190] Embodiment 8.

An eighth embodiment of the present invention will be described with reference to FIGS. In this Embodiment 8, after monitoring the VLAN between all the VLAN termination points of the master node 20A and the slave nodes 30A-30C and detecting a failure, the master node 20A becomes a VLAN in the slave nodes 30A-30C. Change the setting.

A procedure for switching VLANs after failure detection according to Embodiment 8 will be described. Here, an example will be described in which the VLAN setting is changed after a failure is detected between slave node 30A and slave node 30B in the network system shown in FIG.

FIG. 32 is a flowchart showing the procedure for switching VLANs after failure detection according to the eighth embodiment. In the eighth embodiment, since a VLAN failure is detected by the same procedure as in the third and sixth embodiments, the description thereof is omitted. Steps S1100 and S1110 here correspond to steps S900 and S910 of the sixth embodiment shown in FIG.

[0193] In the VLAN processing unit 25 of the master node 20A, VLANs 2 and 3 are working VLANs, and adjacent link disconnection or remote link disconnection is caused by port P2 on the backup VLANs 12 and 13 on the opposite side of VLANs 2 and 3. Since the notification is not received, the VLAN processing unit 25 switches the settings of VLAN 2 and 3 to the spare VLAN. In addition, the VLAN processing unit 25 of the master node 20A releases the blocking state of the port P2 that has received the remote link disconnection notification (step S1120).

[0194] The VLAN processing unit 25 of the master node 20A transmits a VLAN switching request to the slave node 30B through the reverse path. For this VLAN switch request, VLAN 12 is changed to the working VLAN. Instruction information for switching is included.

[0195] The slave node 30B receives the VLAN switching request. The slave node 30B performs VLAN switching processing based on the VLAN switching request from the master node 20A (step S 1130).

[0196] Here, since VLAN 12 is a spare VLAN and a close link is not received at port P2 of VLAN 12, a remote link disconnection is not received, so VLAN 12 is switched to the working VLAN. The VLAN processing unit 25 of the slave node 30B transmits a VLAN switching response indicating that the VLAN switching processing has been completed to the master node 20A.

[0197] The VLAN processing unit 25 of the master node 20A performs VLA to the slave node 30C through the reverse path.

Send N switching request. This VLAN switching request includes instruction information for switching VLAN 13 to the working VLAN.

[0198] The slave node 30C receives the VLAN switching request. The slave node 30C performs VLAN switching processing based on the VLAN switching request from the master node 20A (step S 1140).

[0199] Here, since VLAN 13 is a spare VLAN and a close link is not received at port P2 of VLAN 13, a remote link disconnection is not received, so VLAN 13 is switched to the working VLAN. The VLAN processing unit 25 of the slave node 30C transmits a VLAN switching response indicating that the VLAN switching processing has been completed to the master node 20A.

[0200] The VLAN processing unit 25 of the master node 20A does not transmit a VLAN switching request to the slave node 30A because VLAN 11 is a spare VLAN. When VLAN switching is performed in the network system, the network system is changed to the configuration shown in FIG.

[0201] The master node 20A repeats transmission of a VLAN switching request to the slave nodes 30A-30C for a predetermined time or a predetermined number of times until a VLAN switching response is transmitted from the slave nodes 30A-30C.

[0202] The VLAN processing unit 25 of the slave nodes 30A-30C changes the VLAN table information 86A-86C according to the VLAN switching process and sets new VLAN table information 86X-86Z. Here, the VLAN table information 86X-86Z requires the port blocking status. I don't need it.

As described above, according to the eighth embodiment, the master node 20A can transmit a VLAN switching request to each of the slave nodes 30A-30C. Since each node performs VLAN switching processing based on the VLAN switching request from the master node 20A, it becomes possible to control VLAN switching for each VLAN of the combination of the master node and the slave node. . Therefore, it is possible to quickly set a detour route when a failure occurs between the VLANs of the combination of the master node and the slave node.

[0204] In addition, since the occurrence of a failure is monitored between the end points of the VLAN between the master node 20A and the slave nodes 30A-30C, it is bypassed without controlling the port blocking status or topology information. The route can be set quickly.

[0205] Embodiment 9.

A ninth embodiment of the present invention will be described with reference to FIG. 12, FIG. 33 and FIG. In the ninth embodiment, the master nodes 20A and 20B and the slave nodes 30A and 30B detect the occurrence of a failure by receiving the link disconnection notification and the quality degradation notification, and then a plurality of master nodes are connected to one or more slaves. Have the node switch the VLAN settings.

A VLAN switching procedure after failure detection according to the ninth embodiment will be described. Here, an example will be described in which the VLAN setting is changed after a failure is detected between slave node 30A and slave node 30B of the network system shown in FIG.

FIG. 33 is a flowchart showing a procedure for switching VLANs after failure detection according to the ninth embodiment. For example, as described in the first embodiment and the second embodiment, the master node 2 OA receives the link disconnection notification and the quality degradation notification at the forward ports 21 of VLAN1, 2, 51 and receives the connection determination unit 28. Detects a failure. In addition, the master node 20B receives a link disconnection notification or a quality degradation notification at the reverse port 22 of the VLANs 61 and 62, and the connection determination unit 28 detects the occurrence of a failure (step S1200). The connection determination unit 28 of the master nodes 20A and 20B specifies the port between the slave node 30A and the slave node 30B that are blocked (step S1210).

[0208] The VLAN processing unit 25 of the master nodes 20A and 20B changes the previously set topology information 87A to new topology information 87X (step S1220). Master node 20A, The VLAN processing unit 25 of 20B specifies that the faulty working VLANs are VLAN 61 and VLAN 62 (step S 1230).

[0209] The VLAN processing unit 25 of the master nodes 20A and 20B notifies the link disconnection of the proximity link disconnection or the remote link disconnection by the port P2 of the management spare VLAN 75 corresponding to the management working VLAN 51 (on the opposite side). Since the active VLAN 51 is switched to the protection VLAN, the protection VLAN 75 is switched to the active VLAN 75 (step S1240).

[0210] The VLAN processing unit 25 of the master node 20A releases the blocking state of the port P2 of the master node 20A. Further, the VLAN processing unit 25 of the master node 20B releases the blocking state of the port P2 of the master node 20B.

[0211] The VLAN processing unit 25 of the master nodes 20A and 20B is a VLAN used by each slave node so that the communication traffic volume for each link in the ring network 90 is equalized (the total communication traffic is averaged). Determine the master node that sends topology information 87X, port blocking status, switch request to each slave node, etc. to the slave node (hereinafter referred to as notification source master node). The master nodes 20A and 20B cooperate with each other through the management VLAN 75 to determine a notification source master node (step S 1250).

[0212] For example, the master node 20A is a notification source master node that transmits a switching request to the slave node 30A, and the master node 20B is a notification source master node that transmits a switching request to the slave node 30B.

[0213] The VLAN processing unit 25 of the master node 20A transmits a VLAN switching request to the slave node 30A. This VLAN switching request includes instruction information for switching VLAN 1 to the working VLAN, and instruction information for blocking port P2 of slave node 30A of VLAN 61.

[0214] The slave node 30A receives the VLAN switching request. The slave node 30A performs VLAN switching processing based on the VLAN switching request from the master node 20A (step S1260). Here, the VLAN processing unit 25 of the slave node 30A does not perform the VLAN switching process because VLAN1 is the working VLAN. Further, the VLAN processing unit 25 of the slave node 30A closes the port P2 because the port P2 of the slave node 30A of the VLAN 61 is in the release state. After this, VLAN processing of slave node 30A The unit 25 transmits a VLAN switching response indicating that the VLAN switching processing is completed to the master node 20A.

[0215] The VLAN processing unit 25 of the master node 20B transmits a VLAN switching request to the slave node 30B. This VLAN switching request includes instruction information for switching VLAN 62 to the working VLAN and instruction information for blocking port P1 of slave node 30B of VLAN2.

[0216] The slave node 30B receives the VLAN switching request. The slave node 30B performs the VLAN switching process based on the VLAN switching request from the master node 20B (step S1270). Here, the VLAN processing unit 25 of the slave node 30B switches the VLAN 62, which is a backup VLAN, to the working VLAN. Further, the VLAN processing unit 25 of the slave node 30B closes the port P1 of the slave node 30B of VLAN2. Thereafter, the VLAN processing unit 25 of the slave node 30B transmits a VLAN switching response indicating that the VLAN switching processing is completed to the master node 20A.

[0217] The master nodes 20A and 20B repeat the transmission of the VLAN switching request to the slave nodes 30A and 30B for a predetermined time or a predetermined number of times until the VLAN switching response is transmitted from the slave nodes 30A and 30B. .

FIG. 34 is a diagram showing a configuration after VLAN switching of the network system shown in FIG. The link between master node 20A and master node 20B is released from blocking, and the link between slave node 30A and slave node 30B is blocked link 56. Even after the VLAN is changed by each node in the ring network 90, information is transmitted and received in the same procedure as the information transmission and reception in the network system according to the first embodiment.

[0219] Thus, according to the ninth embodiment, VLAN switching processing is performed by a plurality of master nodes to a plurality of slave nodes so that the communication traffic amount for each link in the ring network 90 is equalized. Therefore, it is possible to set a detour route by effectively using resources in the ring network 90.

[0220] Embodiment 10.

A tenth embodiment of the present invention will be described with reference to FIGS. This implementation In Form 10, after monitoring the VLAN between all the VL AN termination points of master nodes 20A, 20B and slave nodes 30A, 30B and detecting a failure, multiple master nodes become VL to multiple slave nodes. Change the AN setting.

A procedure for switching VLANs after failure detection according to the tenth embodiment will be described. Here, an example is described in which the VLAN setting is changed after a failure is detected between slave node 30A and slave node 30B in the network system shown in FIG.

FIG. 35 is a flowchart showing a procedure for switching VLANs after failure detection according to the tenth embodiment. In the tenth embodiment, a VLAN failure is detected by the same procedure as in the third, sixth, and eighth embodiments, and the description thereof is omitted. Steps S1300 and S1310 in this case correspond to steps S1100 and S1110 of the eighth embodiment shown in FIG.

[0223] The VLAN processing unit 25 of the master nodes 20A and 20B detects a VLAN failure in the management spare VLAN 75 corresponding to the management working VLAN 51 (on the opposite side). In addition to switching to the spare VLAN, the spare VLAN 75 is switched to the working VLAN 75 (step S 1320).

[0224] The VLAN processing unit 25 of the master nodes 20A and 20B includes the VLAN used by each slave node, topology information 87X, port blocking state, so that the communication traffic volume for each link in the ring network 90 is equalized. Determine the notification master node for each slave node. The master nodes 20A and 20B cooperate with each other through the management VLAN 75 to determine a notification source master node (step S 1330).

[0225] For example, the master node 20A is a notification source master node that transmits a switching request to the slave node 30A, and the master node 20B is a notification source master node that transmits a switching request to the slave node 30B.

[0226] Since VLAN 1 is the working VLAN, master node 20A does not send a VLAN switch request to any slave node. The VLAN processing unit 25 of the master node 20B transmits a VLAN switching request to the slave node 30B. This VLAN switching request includes instruction information for switching the VLAN 62 to the working VLAN.

[0227] The slave node 30B receives the VLAN switching request. Slave node 30B Based on the VLAN switching request from the node 20B, the VLAN switching processing is performed (step S 1340).

That is, the VLAN processing unit 25 of the slave node 30B switches the VLAN 62, which is a backup VLAN, to the working VLAN, and switches the VLAN 2, which is the working VLAN, to the protection VLAN. Thereafter, the VLAN processing unit 25 of the slave node 30B transmits a VLAN switching response indicating that the VLAN switching processing is completed to the master node 20A.

[0229] Master node 20B repeats the transmission of a VLAN switching request to slave node 30B for a predetermined time or a predetermined number of times until a VLAN switching response is transmitted from slave node 30B.

[0230] Thus, according to the tenth embodiment, the VLA N switching process is performed by a plurality of master nodes to a plurality of slave nodes so that the communication traffic volume for each link in the ring network 90 is equalized. Therefore, it is possible to set a detour route by effectively using resources in the ring network 90.

[0231] In addition, since the occurrence of a failure is monitored between the end points of the VLAN between the master nodes 20A and 20B and the slave nodes 30A and 30B, it is possible to control the port blocking state and topology information. It is possible to quickly set a detour route.

Industrial applicability

[0232] As described above, the communication network system and the failure detection apparatus according to the present invention are suitable for detecting network failures and avoiding network failures.

Claims

The scope of the claims

[1] A master node connected to an upper network as a layer 2 switch connected in a ring shape and a slave node connected to a lower network, and a virtual LAN connecting the master node and the slave node is connected to the master node Set in two different communication path directions along the ring for every combination of the slave nodes and open one port at the link end in the ring of the master node or the slave node. A ring-shaped communication network system,

The master node and the slave node are

Two communication ports that transmit and receive information between adjacent links adjacent to its own node, and a failure detection unit that detects a communication failure based on information received via the communication port,

When detecting a communication failure, the failure detection unit transmits communication failure information related to the communication failure to a communication port different from the communication port that received the information when the communication failure was detected. When the communication failure information is received from another node, the communication failure information is transferred to a communication port different from the communication port that has received the communication failure information.

[2] The communication port transmits and receives information for monitoring a lower layer between the link adjacent to the own node,

2. The failure detection unit detects a link break of a lower layer between the adjacent links as a communication failure when reception of information for monitoring the lower layer is interrupted by the communication port. The communication network system described in 1.

3. The failure detection unit according to claim 1, wherein when the transmission quality of information received by the communication port deteriorates, the failure detection unit detects a deterioration in transmission quality between the adjacent links as a communication failure. Communication network system.

[4] The master node and the slave node are:

A first virtual LAN setting unit that changes the setting of the virtual LAN so as to avoid transmission / reception of information between links in which the communication failure has occurred when the failure detection unit of the device itself detects a communication failure; A first port changing unit that changes blocking or non-blocking of the communication port when the failure detecting unit of itself detects a communication failure;

The communication network system according to claim 1, further comprising:

[5] The master node is

A second virtual LAN setting unit that changes the setting of the virtual LAN so as to avoid transmission / reception of information between links in which the communication failure has occurred when the failure detection unit of the device itself detects a communication failure;

A second port changing unit that changes blocking or non-blocking of the communication port when the failure detecting unit of itself detects a communication failure;

When its own fault detection unit detects a communication fault, the VLAN change information for instructing the virtual LAN setting change so as to avoid the transmission / reception of information between the links where the communication fault has occurred and the communication port is blocked or A change instructing unit that transmits port change information for instructing non-blocking setting change to the slave node, and

The slave node is configured to change the virtual LAN setting based on the VLAN instruction information from the change instruction unit, and based on the port change information of the change instruction unit power. The communication network system according to claim 1, further comprising a third port changing unit that changes the setting of blocking or non-blocking of the communication port.

[6] When the master node and the slave node have multiple forces,

The master node is

A fourth virtual LAN setting unit that changes the setting of the virtual LAN so as to avoid transmission / reception of information between links in which the communication failure has occurred when the failure detection unit of the device itself detects a communication failure;

A fourth port changing unit that changes blocking or non-blocking of the communication port when the failure detecting unit of itself detects a communication failure;

When the failure detection unit of the master node detects a communication failure,

Based on information transmitted and received between the plurality of master nodes,

Configure the virtual LAN to avoid sending and receiving information between links where communication failure has occurred. A transmission destination determination unit that determines, for each master node, a slave node that is a transmission destination of the VLAN change information for instructing a fixed change and the port change information for instructing a change in the setting of blocking or non-blocking of the communication port; ,

A third change instructing unit that transmits the VLAN change information and the port change information to the communication port to the slave node based on a result determined by the transmission destination determining unit;

The slave node is configured to change a setting of the virtual LAN based on VLAN instruction information from the change instruction unit, and based on the port change information of the change instruction unit power. The communication network system according to claim 1, further comprising a fifth port changing unit that changes the setting of blocking or non-blocking of the communication port.

[7] A master node connected to an upper network as a layer 2 switch connected in a ring shape and a slave node connected to a lower network, and a virtual LAN connecting the master node and the slave node is connected to the master node For each combination of the slave nodes, setting is made in two different communication path directions along the ring, and the link end port of one set of links by the connection between the master node and the slave node is blocked. An open ring communication network system,

The master node and the slave node are

Two communication ports that transmit and receive information between adjacent links adjacent to its own node, and a failure detection unit that detects a communication failure based on information received at the termination point of the virtual LAN via the communication port; With

When detecting a communication failure, the failure detection unit transmits communication failure information related to the communication failure to the communication ports in the two different communication path directions for each virtual LAN set between the master node and the slave node. A communication network system characterized by having

[8] The master node and the slave node are:

When the failure detection unit of itself detects a communication failure, a first virtual LAN setting that changes the setting of the virtual LAN so as to avoid transmission / reception of information between the links in which the communication failure has occurred. The communication network system according to claim 7, further comprising a fixing unit.

[9] The master node is

When its own fault detection unit detects a communication fault, it sends to the slave node VLAN change information for instructing the virtual LAN setting change so as to avoid transmission / reception of information between the links where the communication fault has occurred. A change instruction unit,

8. The request according to claim 7, wherein the slave node further includes a third virtual LAN setting unit that changes the setting of the virtual LAN based on VLAN instruction information from the change instruction unit. Communication network system.

[10] When the master node and slave node have multiple forces,

The master node is

A transmission destination determination unit that determines, for each master node, a slave node that is a transmission destination of VLAN change information for instructing a change in the setting of the virtual LAN so as to avoid transmission and reception of information between links in which a communication failure has occurred. When,

A second change instructing unit that transmits the VLAN change information to the slave port based on a result determined by the transmission destination determining unit;

8. The request according to claim 7, wherein the slave node further includes a fifth virtual LAN setting unit that changes the setting of the virtual LAN based on VLAN instruction information from the change instruction unit. Communication network system.

[11] As a layer 2 switch connected in a ring shape, a master node connected to the upper network and a slave node connected to the lower network are provided, and the master node and the slave are connected. The virtual LAN connecting the slave node is set in two different communication path directions along the ring for every combination of the slave nodes with respect to the master node, and within the ring of the master node or the slave node. An open ring communication network system in which a pair of ports at the link end of

The master node and the slave node are

In addition to having two communication ports for sending and receiving information between adjacent links adjacent to its own node,

The master node includes a failure detection unit that detects a communication failure based on information transmitted from the blocked ring-end node via the communication port;

The failure detection unit transmits failure detection information for detecting a communication failure to the blocked ring end slave node, and includes the information for identifying the blocked ring end node. A communication network system for detecting a communication failure based on response information transmitted from a node at a ring end.

The master node is

A first virtual LAN setting unit that changes the setting of the virtual LAN so as to avoid transmission / reception of information between links in which the communication failure has occurred when the failure detection unit of the device itself detects a communication failure;

A first port changing unit that changes blocking or non-blocking of the communication port when the failure detecting unit of itself detects a communication failure;

When the communication port receives the VLAN change information and the port change information, the failure detection unit of the slave node assigns the VLAN to a communication port different from the communication port that has received the VLAN change information and the port change information. Transfer the change information and the port change information.

The slave node is based on the VLAN instruction information from the change instruction unit. A second virtual LAN setting unit for changing the setting of the virtual LAN, and a second port changing unit for changing the setting of blocking or non-blocking of the communication port based on the port change information of the change instruction unit. The communication network system according to claim 11, further comprising:

The slave is connected in a ring shape together with the slave node of the layer 2 switch connected to the lower network on the communication network, and the slaves in two communication path directions differing along the ring for every combination with respect to the slave node. In a fault detection device for a layer 2 switch in which a virtual LAN connected to a node is set and a pair of ports at the link end in the ring is placed in a blocked ring network and connected to an upper network,

Two communication ports that send and receive information between adjacent links,

A failure detection unit that detects a communication failure based on information received via the communication port;

When the slave node detects a communication failure, the slave node transmits communication failure information related to the communication failure to a communication port that is different from the communication port that received the information when the communication failure is detected. When the communication failure information is received from the communication port, the communication failure information is transferred to a communication port different from the communication port that has received the communication failure information.

The failure detection device, wherein the failure detection unit detects a communication failure based on the communication failure information transferred from the slave node.