JP2009010459A - Transmission path system, ring map generation method, and node - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To collect information on nodes efficiently in a transmission path system where a plurality of nodes are connected in a ring. <P>SOLUTION: Respective nodes 1-6 are dynamically determined to be one of A terminal station that blocks the transmission of a frame around A system and enables the transmission of a frame around B system, B terminal station that enables the transmission of a frame around the A system and terminates the transmission path of a frame around the B system, and an intermediate station enabling the transmission of frames around the A, B systems. The A terminal station generates a frame and adds information on its own node for transmitting around the B system. The intermediate station adds information on its own node for transmitting around the B system when the frame is received. The B terminal station adds information on its own node to a ring map described in the received frame for completing the ring map when the frame is received. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for generating a ring map that is information of each node in a transmission line system in which a plurality of nodes are connected in a ring shape via a transmission line.

  There are various types of networks formed by connecting a plurality of nodes. Among these network shapes, there is a ring network formed by connecting a plurality of nodes in a ring shape.

  Further, it is necessary to collect information on a plurality of nodes constituting the network and output the collected information to a display device of a terminal connected to the node. Thereby, the network administrator can grasp the configuration of the network by referring to the node information output to the display device.

In the ring network described above, as a technique for collecting information on a plurality of nodes constituting the network, for example, a packet is transmitted to the next node starting from a node to which a centralized monitoring device is connected, and the packet is received by a receiving node. A ring network technique for checking the connection order of nodes by adding its own node address to the centralized monitoring device is disclosed (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-262073

  However, in the technique described in Patent Document 1 described above, for example, when a failure occurs in a transmission line such as a line or a node connecting nodes, a packet is not transmitted beyond the point where the failure occurs. Another problem is that node information cannot be collected without packets reaching the centralized monitoring apparatus.

  In addition, a packet is transmitted from two nodes adjacent to the point where the failure occurs so that they are opposite to each other, and the receiving node adds its own node address to the packet and circulates to the centralized monitoring device. When receiving packets from both sides, information in the two received packets can be integrated to collect node information. However, since it is necessary to perform processing for integrating information in two packets, there is a problem in that node information cannot be collected efficiently.

  Accordingly, an object of the present invention is to efficiently collect node information in a transmission line system in which a plurality of nodes are connected in a ring shape.

  In order to solve the above-mentioned problem, in the transmission line system of the present invention, a plurality of nodes are connected in a ring shape via transmission lines around the A system and the B system, and each of the plurality of nodes is connected around the A system. A master node capable of blocking frame transmission and transmitting a frame around system B; and a terminal station node capable of transmitting a frame around system A and terminating a transmission path of a frame around system B; The intermediate station node capable of transmitting frames around the A system and the B system is dynamically determined to be one of them.

  The master node generates a ring map generation frame for generating a ring map that is information relating to a plurality of nodes, adds the information of the own node to the generated ring map generation frame, and transmits the frame around the B system.

  When the intermediate station node receives the ring map generation frame from the adjacent node, it adds the information of its own node to the received ring map generation frame and transmits it around the B system.

  When the terminal station node receives the ring map generation frame from the adjacent node, the terminal station node completes the ring map by adding the information of the own node to the ring map described in the received ring map generation frame.

  According to the present invention, it is possible to efficiently collect node information in a transmission line system in which a plurality of nodes are connected in a ring shape.

FIG. 1 is a diagram showing a logical basic concept of a transmission line system according to an embodiment of the present invention, here, a bidirectional double ring transmission line system.
In FIG. 1, reference numerals 1 to 6 are nodes as frame transmission apparatuses, and each is assigned a unique node number and a node state. These are assigned around the A system (clockwise), B A network is constructed by appropriately connecting through two transmission lines 9 and 10 around the system (counterclockwise).
In FIG. 1, reference numeral 1 denotes one terminal state (master node) (hereinafter referred to as A terminal station), which blocks transmission on the second port (port B) side (indicated by a thumbprint in the figure). It is a node. For this reason, in the A terminal station 1, the first port (port A) side is called the inside of the network, and the port B side is called the outside of the network. In the A terminal station 1, frame transmission is performed only on the port A side. Reference numeral 2 denotes the other terminal state (terminal station node) (hereinafter referred to as B terminal station), which is a node that terminates the transmission line 10 around the B system (counterclockwise). In the B terminal station 2, the port B side is called the inside of the network, and the port A side is called the outside of the network. In the B terminal station 2, the frame is transmitted only on the port B side.

Reference numerals 3 to 6 are intermediate stations, and frames can be transmitted to both the transmission path 9 around system A (clockwise) and the transmission path 10 around system B (counterclockwise). It is a node. The intermediate stations 3 to 6 are both connected to the network in the ports A and B, and frame transmission is performed bidirectionally on both the port A side and the port B side.
Reference numerals 7 and 8 denote terminals (PC: personal computer) (computers) connected to the nodes assigned as the A terminal station 1, the B terminal station 2, and the intermediate stations 3 to 6, respectively. The terminals 7 and 8 generate user frames and exchange data using the transmission path 9 around the A system (clockwise) or the transmission path 10 around the B system (counterclockwise). Note that the thick arrows in FIG. 1 schematically show data exchange.

FIG. 2 is a diagram showing the types of frames transmitted and received in the transmission line system according to the present embodiment. In the figure, a broken line indicates a ring image of the ring type transmission line.
Here, in addition to the user frame c transmitted between the A terminal station and the B terminal station, the inter-adjacent frame a as a first control frame used between adjacent nodes, and the A terminal station are generated. A network control frame b is prepared as a second control frame for network control, which is multicast transmitted in the network and finally returned (received) to the A terminal station.

  Note that the user frame c includes a TCP (Transmission Control Protocol) and a UDP (User Datagram Protocol) frame transmitted and received by the own node as well as a frame flowing from a branch area LAN (Local Area Network) (not shown).

The inter-adjacent frame a is used as a frame for confirming the soundness (disconnection, connection) of the transmission path between adjacent nodes. Specifically, each of the nodes 1 to 6 in FIG. 1 communicates with each other by exchanging an inter-adjacent frame with each other's adjacent nodes to perform handshake. Here, the state in which the logical handshake with the adjacent node is completed is defined as link up. With this inter-adjacent frame, transmission path fault monitoring and transmission quality degradation are monitored.
The ring map generation frame d is used as a ring map generation frame for generating a ring map that is information regarding a plurality of nodes.
The network control frame b includes a contention start trigger frame, a failure adjacent A declaration frame, a failure adjacent A transition frame, and a failure adjacent A transition response frame.

The contention start trigger frame is used to arbitrate one or more A terminal stations existing in the network to one node. Specifically, a plurality of A terminal stations compete with each other at the time of failure recovery, and have a priority. Based on the arbitration based on this, it becomes an opportunity to arbitrate one or more A terminal stations to one node.
The failure adjacent A declaration frame is used to declare that the own station is the failure adjacent A terminal station. Specifically, since the own station has the highest priority as the A terminal station, the contention start trigger The contention is canceled in response to the contention request by the frame, and the other node requests to transit to the intermediate station.
The failure adjacent A transition frame is used to declare that the own station has transitioned to the failure adjacent A terminal station. Specifically, since the own station has the highest priority as the A terminal station, the contention start trigger frame is used. The contention request is canceled and the other node requests to transit to the intermediate station.
The failure adjacent A transition response frame is used as a response frame for the node that has transmitted the failure adjacent A transition frame. Specifically, the failure adjacent A transition response frame is a failure adjacent A transition frame transmitted by the failure adjacent A terminal station. Is transmitted to the B terminal station, and thereby, a transmission path between the A terminal station and the B terminal station can be secured.
The ring map transfer frame e is used to transfer the completed ring map to another station.

  FIG. 3 is a diagram showing a data format of a frame used in the transmission line system according to the present embodiment. (A) Frame between adjacent frames, ring map generation frame, (b) Network control frame, ring map transfer Each of the frame and (c) user frame is shown.

As shown in FIG. 3A, the inter-adjacent frame includes fields of a destination address, a transmission source address, a tag, a frame length / type, a data area, and a CRC (Cyclic Redundancy Check). As shown in FIG. 3B, the network control frame is composed of fields of a destination address, a transmission source address, a tag, a frame length / type, a data area, and a CRC.
The frame identification number assigned to the data area is used to identify the contention start trigger frame, the failure adjacent A declaration frame, the failure adjacent A transition frame, and the failure adjacent A transition response frame. This information is used to validate any one frame according to the priority assigned as control information when the frames compete. The tag is used for identification for assigning an arbitrary port to a plurality of VLANs (Virtual LANs). Further, the above-described inter-adjacent frame, network control frame, and ring map transfer frame are identified by a unique destination address value. Furthermore, the ring map generation frame is identified by the value of the frame identification number.

Also, as shown in FIG. 3C, the user frame is composed of fields of destination address, transmission source address, frame length / type, data area, and CRC.
Note that the inter-adjacent frame and the network control frame are transmitted using multicast. Therefore, as each of the nodes 1 to 6 in FIG. 1, a node having a VLAN function for virtually dividing a multicast domain into a plurality is used.

FIG. 4 is a block diagram showing the internal configuration of the data transmission apparatus according to this embodiment, and specifically shows the internal configuration of each of the nodes 1 to 6 shown in FIG.
The data transmission apparatus according to this embodiment includes a port A (11), a port B (12), a port state control unit 13, a reception buffer 14, a reception frame control unit 15, a transmission buffer 16, and a transmission frame. It comprises a control unit 17, a network control unit 18, a ring map control unit 19, and a ring map holding unit 20. The port state control unit 13, the reception frame control unit 15, the transmission frame control unit 17, the network control unit 18, the ring map control unit 19, and the ring map holding unit 20 function as a processing unit.

The port state control unit 13 exchanges adjacent frames between adjacent nodes 1 to 6 to perform a handshake periodically, and troubles the transmission paths 9 and 10 (FIG. 1) around the A system and the B system. Monitor.
The port state control unit 13 determines the destination address of the inter-adjacent frame or the network control frame received via the port A (11) and the port B (12), and determines the port B (12) and the port A. Whether to forward or block the transmission of the inter-adjacent frame or network control frame for (11) is determined and stored in the reception buffer 14 via the reception frame control unit 15.

Further, the port state control unit 13 outputs the ring map generation frame received via the port B (12) to the ring map control unit 19, and the ring map to which the information of the own node is added from the ring map control unit 19 When the generation frame is returned, the returned ring map generation frame is transmitted via the port A (11).
Further, the port state control unit 13 outputs the ring map described in the ring map transfer frame received via the port A (11) to the ring map holding unit 20, and also receives the received ring map transfer frame. Transmit via port B (12).
Further, when the ring map transfer frame is input from the ring map control unit 19, the port state control unit 13 transmits the input ring map transfer frame via the port B (12).

  The network control unit 18 receives a network control frame transmitted by multicast using the transmission path 9 around the A system from the node that transitions to the faulty adjacent A terminal station when the failure of the transmission path 9 (10) is detected. A single A terminal station determined by arbitrating one or more A terminal stations that block transmission of user frames using the port B (12), and adjacent to the only A terminal station, Transmission is performed by port B, and a transmission path is reestablished between the node that transitions to the faulty adjacent B terminal station that terminates the transmission path 10 around the B system.

  Further, the network control unit 18 uses the frame identification number included in the network control frame stored in the reception buffer 14 so that the network control frame is transmitted around the transmission line 9 (10) around the A system or the B system where the failure has occurred. When recovery is detected, one of a conflict start trigger frame, a failure adjacent A declaration frame, a failure adjacent A transition frame, or a failure adjacent A transition response frame is determined, and the state transition of each node is controlled according to the determination result To do.

  Further, when transmitting the inter-adjacent frame and the network control frame based on the state of each node, the network control unit 18 reads the corresponding frame from the transmission buffer 16 via the transmission frame control unit 17 and transmits it to the port state control unit 13. At this time, the port state control unit 13 determines the tag included in the received corresponding frame, determines whether to transmit to the port A (11) or the port B (12), and transmits.

That is, the port state control unit 13 and the network control unit 18 described above function as means (1) to (4) listed below by cooperating with the port state control unit and the network control unit in other nodes. . With these functions, when a failure in the transmission line 10 is detected, the network is reconstructed as appropriate, and the state of each node is dynamically determined.
(1) Regarding the state of its own node, the transmission of the frame using the port B (12) is blocked, and the transmission of the A terminal station and the transmission path 10 around the B system using the port A (11) for the transmission of the frame is performed. Terminate and transmit the frame to the terminal station and transmission path that transmit the frame using port B (12), and transmit the frame bidirectionally using both port A (11) and port B (12) (2) A frame between adjacent nodes is exchanged with an adjacent node, a transmission path 9 around the A system, and a transmission path around the B system. (3) The node that has detected the failure as a result of monitoring transmits a network control frame by multicast using the transmission path 10 around the B system, and the node A The transition to the terminal As a result, means for transitioning the adjacent node around the B system to the terminal station and the other node to the intermediate station (4) As a result of monitoring, the A terminal station that has detected the recovery of the fault is the transmission line around the A system. 9 is used to transmit a network control frame by multicast, and arbitration is performed by one or more A terminal stations that have received this network control frame, and a transition is made to an intermediate station as a result of the arbitration. Means for Reconstructing Network with Node Transitioning to Terminal Station via Other Nodes Details of any of the above means will be described later.

  The ring map control unit 19 performs processing based on the state of the own node. That is, when the state of the own node is the intermediate station node, when the ring map generation frame is input from the port state control unit 13, the ring map control unit 19 adds the ring map generation frame to the input ring map generation frame. The node information is added and output to the port state control unit 13.

  When the state of the own node is the terminal station node, the ring map control unit 19 is described in the input ring map generation frame when the ring map generation frame is input from the port state control unit 13. The node information is added to the ring map to complete the ring map, and the completed ring map is output to the ring map holding unit 20.

  Further, the ring map control unit 19 may further generate a ring map transfer frame in which the completed ring map is described and output it to the port state control unit 13. As a result, the ring map transfer frame can be transmitted to other nodes, and some or all of the nodes that have received the ring map transfer frame internally retain the ring map described in the ring map transfer frame. It becomes possible to do. If a ring map is held inside the node, the terminal 7 (8) (see FIG. 1) connected to the node can display the ring map on a display device (not shown). Thus, the administrator can grasp configuration information indicating what kind of node the network is configured by referring to a ring map displayed on a display device (not shown).

  When the state of the own node is the master node, the ring map control unit 19 generates a ring map generation frame, for example, every predetermined time (for example, every 3 seconds), and generates the generated ring map. The node information is added to the generation frame and output to the port state control unit 13.

  Here, when the state of the own node is the intermediate station node, the terminal station node, and the master node, the information of the own node added to the ring map generation frame is not particularly limited. For example, the MAC address ( It may be the address of its own node such as a Media Access Control address) or an IP address (Internet Protocol address), or may indicate the status of its own node such as a master node, an intermediate station node, or a terminal station node. . Further, it may be information (for example, a MAC address or an IP address) of the terminal 7 (8) (see FIG. 1) connected to the own node. The area to which the information of the own node is added may be anywhere in the ring map generation frame, but may be a data area (see FIG. 3A), for example. In each node, it is preferable to add the information of the own node to the ring map generation frame after the information of other nodes. As a result, the administrator can grasp the connection order of the nodes together with the configuration information described above.

  When a ring map is input from the port state control unit 13, the ring map holding unit 20 stores the input ring map inside (for example, a storage unit (not shown) in the own node).

6 to 13 are diagrams showing network construction operations in the transmission line system according to the present embodiment. Both are shown based on the physical configuration of the transmission line system of the present invention shown in FIG. The state of each node is dynamically determined by the network construction operation shown in FIGS.
6 and 7 show network control procedures when a failure occurs, FIGS. 8 and 9 show network control procedures when a failure is recovered, and FIGS. 10 and 11 show network control procedures when a plurality of loops are integrated. FIG. 12 and FIG. 13 show the network control procedure when the power is turned on. 6 to 13, a circle indicates a port allocated as a relay port, a circle indicates a port allocated as a logical switching port, and ‖ indicates a blocking (logical disconnection) state. Also, in the figure, the numbers # 1 to # 6 assigned to the nodes correspond to the numbers 1 to 6 of the ports shown in FIG.

  Hereinafter, a network construction operation in the transmission line system according to the present embodiment will be described in detail with reference to FIGS.

  First, network control when a failure occurs will be described with reference to FIGS. Here, node # 1 is assigned to the A terminal station, port B is blocked, node # 2 is assigned to the B terminal station, port A is blocked, and each of nodes # 3 to # 6 is networked as an intermediate station. Will be described as being constructed.

Each node # 1 to # 6 confirms the soundness of the transmission line 9 (10) by periodically executing inter-adjacent frame communication (FIG. 6A). It is assumed that a failure has occurred due to n consecutive failures of the inter-adjacent frame. Here, it is assumed that a failure due to disconnection has occurred between nodes # 4 to # 5 by detecting the failure of 3 consecutive times. (FIG. 6B).
As a result, the node # 4 that detected the failure makes a transition to the failure adjacent A terminal station mode, and multicasts a frame (failure adjacent A transition frame) that declares that it has changed to the failure adjacent A terminal station around the B system. To do. In response, node # 5 transitions to the faulty adjacent B terminal mode (FIG. 6C).

On the other hand, the node # 1 receives the failed adjacent A transition frame, recognizes that there is another A terminal station, transitions to the intermediate station, and cancels blocking. Further, the node # 2 recognizes that the node # 1 is not the B terminal station when the node # 1 becomes the intermediate station, and transitions to the intermediate station to release the blocking (FIG. 7D).
Subsequently, since the node # 5 has transitioned to the failure adjacent B terminal mode, when receiving the failure adjacent A transition frame, the node # 5 multicasts a response frame (failure adjacent A transition response frame) around the A system (FIG. 7E). ).
The node # 4 recognizes that there is a response from the terminal B by receiving the faulty adjacent A transition response frame, and stops transmitting the faulty adjacent A transition frame. Each of the nodes # 1 to # 6 continues to check the soundness of the transmission path by periodically communicating the adjacent frames (FIG. 7 (f)).

Next, network control at the time of failure recovery will be described with reference to FIGS. Here, a failure such as disconnection occurs between the nodes # 4 to # 5, the node # 4 becomes the faulty adjacent A terminal station, the port B is blocked, and the node # 5 becomes the faulty adjacent B terminal station. A is blocked, and the network is constructed with the nodes # 1 to # 3 and # 6 as intermediate stations.
Each node # 1 to # 6 confirms the soundness of the transmission line 9 (10) by periodically executing inter-adjacent frame communication (FIG. 8A).

Next, it is assumed that the failure has been recovered by connecting the disconnection that occurs between the nodes # 4 to # 5. Here, it is detected that the inter-adjacent frame communication has succeeded three times in succession, and the failure recovery between the nodes # 4 to # 5 is recognized (FIG. 8B).
When the port B is linked up, the node # 4 transitions from the faulty adjacent A terminal station mode to the logical disconnection A terminal station contention mode, and multicasts a contention start trigger frame around the A system. As a result, the node # 5 makes a transition from the failure adjacent B terminal station mode to the logically disconnected B terminal station mode when the port A is linked up (FIG. 8C).

The intermediate station and the B terminal station ignore the contention start trigger frame transmitted from the node # 4. For this reason, the node # 4 recognizes that only the node A exists in the network by receiving the contention start trigger frame transmitted by the node # 4. As a result, the node # 4 transitions from the logical disconnection A terminal station contention mode to the logical disconnection A terminal station mode (FIG. 9D).
The nodes # 1 to # 6 continue to check the soundness of the transmission line 9 (10) by periodically exchanging frames between adjacent nodes thereafter (FIG. 9 (e)).

  Next, network control at the time of integrating a plurality of loops will be described with reference to FIGS. Here, it is assumed that a failure has occurred between the nodes # 1 and # 2, and between the nodes # 4 and # 5, and the node # 1 and the node # 4 are the failure adjacent A terminal stations, blocking the port B, and the node # 2 and node # 5 become the faulty adjacent B terminal station port, block port A, and the network is constructed with node # 3 and node # 6 as intermediate stations.

Each node # 1 to # 6 confirms the soundness of the transmission line 9 (10) by periodically performing inter-adjacent frame communication (FIG. 10A).
Here, it is assumed that the failure between the nodes # 1 and # 2 has been recovered. That is, when the inter-adjacent frame is succeeded three times in succession, the node # 1 serving as the faulty adjacent A terminal station detects the fault recovery between the nodes # 1 and # 2 (FIG. 10B).
Subsequently, the node # 1 transitions from the failure adjacent A terminal mode to the logical disconnection A terminal contention mode when the port B is linked up, and multicasts a contention start trigger frame around the A system. Further, the node # 2 transitions from the failure adjacent B terminal station mode to the logically disconnected B terminal station mode when the port A is linked up (FIG. 10 (c)).

Nodes # 3 and # 6 as intermediate stations and nodes # 2 and # 5 as B terminal stations ignore the contention start trigger frame transmitted from node # 1. The node # 4 receives the contention start trigger frame. At this time, the node # 4 is in the faulty adjacent A terminal mode and has the highest priority. Therefore, the failure adjacent A declaration frame is transmitted to the node # 1, which is the transmission source of the contention start trigger frame, to notify that the own node has high priority (FIG. 11 (d)).
Node # 1 receives the faulty adjacent A declaration frame and recognizes that there is an A terminal with high priority in the network. For this reason, a transition is made from the logical disconnection A terminal station contention mode to the intermediate station to release the blocking. Also, node # 2 recognizes that its own node is not a B terminal because node # 1 becomes an intermediate station, and transitions to the intermediate station to release blocking. Each node continues to check the soundness of the transmission path by periodically exchanging frames between adjacent nodes (FIG. 11 (e)).

Finally, a network control procedure at power-on will be described with reference to FIGS. Here, it is assumed that the node # 1 and the node # 2 are started up among the three nodes, and the node # 3 is still powered off (FIG. 12A).
First, the nodes # 1 and # 2 that are powered on transition from the power-off state to the isolated mode. Subsequently, when the inter-adjacent frame succeeds three times in succession and the nodes # 1 and # 2 link up, the node # 1 changes from the isolated mode to the faulty adjacent B terminal, and the node # 2 A transition is made to the faulty adjacent A terminal mode (FIG. 12B).

Next, assume that node # 3 is started up. As a result, the node # 3 transitions from the power-off state to the isolated mode (FIG. 12C).
Subsequently, the node # 3 transitions from the isolated mode to the faulty adjacent B terminal mode when the inter-adjacent frames succeed three times in succession. Also, node # 1 transitions from the failure adjacent B terminal station mode to the intermediate station when port A is linked up, and releases blocking (FIG. 13 (d)).

Subsequently, when the inter-adjacent frame between the node # 2 and the node # 3 succeeds three times in succession, the node # 3 transitions from the faulty adjacent B terminal mode to the logically disconnected B terminal mode. Node # 2 transitions from the faulty adjacent A terminal mode to the logical disconnection A terminal contention mode when port B is linked up, and multicasts a contention start trigger frame around the A system (FIG. 13). (E)).
At this time, the node # 1 that is the intermediate station and the node # 3 that is the B terminal station ignore the contention start trigger frame transmitted from the node # 2. Also, since the contention start trigger frame transmitted by the node # 2 is returned, the node # 2 recognizes that the A terminal station exists only in the network. Node # 2 then transitions from the logical disconnection A terminal station competition mode to the logical disconnection A terminal station mode.
The nodes # 1 and # 3 continue to check the soundness of the transmission path by periodically exchanging frames between adjacent nodes thereafter (FIG. 13 (f)).

  FIG. 14 is a diagram illustrating state transition between modes of the transmission line system according to the present embodiment. The operation | movement demonstrated using FIGS. 6-13 is typically shown. In the figure, “up” indicates a state in which the adjacent station is logically connected, and “down” indicates a state in which it is logically disconnected.

As described above, in the present embodiment, a plurality of nodes # 1 to # 6 transmit frames using the transmission path 9 around the A system and the transmission path 10 around the B system. Block the transmission of the control frame using port B, terminate the A terminal station using port A for the transmission of the frame, terminate the transmission path around the B system, and terminate the frame transmission using port B A transmission path system is constructed by allocating to a station node and (3) an intermediate node that transmits and receives frames to and from both transmission paths and performs bidirectional transmission of frames using both port A and port B. .
At this time, each of the nodes # 1 to # 6 (frame transmission apparatus) exchanges a first control frame with an adjacent node to monitor a transmission path failure. Then, the node that has detected the failure transmits the second control frame by multicast using the transmission path 10 around the B system, notifies other nodes that it has transitioned to the A terminal station, The node to be transferred is changed to the terminal station node, and the other node is changed to the intermediate station node. On the other hand, the A terminal station that has detected the recovery of the failure multicasts the second control frame using the transmission path 9 around the A system, and arbitrates by one or more A terminal stations that have received the second control frame. The network between the only A terminal station that is determined and determined and the node that transitions to the terminal station node via the other node that transitions to the intermediate station node as a result of arbitration is reconstructed.

As a result, in the bi-directional double ring transmission line system, detection of occurrence and recovery of a transmission line failure can be realized by a handshake in which the first control frame is exchanged between adjacent nodes. The node that detects the failure transitions to the A terminal station, performs arbitration by multicasting the second control frame, and reconstructs the network, thereby reducing the time required for logical topology construction.
The second control frame also has a meaning as a trigger for exchanging topology information. Since the second control frame is notified to each node all at once by multicast, the processing for topology construction and topology restoration is accelerated. can do.

  In addition, according to the above-described embodiment of the present invention, only the disconnection of the transmission line is illustrated and described as the failure. However, for the node failure and the like as well, the adjacent failure detection node operates as the A terminal station. There are similar effects.

  FIGS. 15 to 16 are diagrams showing operations for generating and transferring a ring map in a transmission line system (see FIGS. 6 to 13) in which the state of each node is dynamically determined. FIG. 15 shows a procedure of ring map generation and ring map transfer before the occurrence of a failure, and FIG. 16 shows a procedure of ring map generation and ring map transfer after the occurrence of a failure.

  Hereinafter, the operations of ring map generation and ring map transfer in the transmission line system according to the present embodiment will be described in detail with reference to FIGS.

  As shown in FIG. 15A, the node # 1, which is the A terminal, for example, generates a ring map generation frame every predetermined time, and adds the information of the own node to the generated ring map generation frame. Then, it transmits in one direction (around B system). When nodes # 6, # 5, # 4, and # 3, which are intermediate stations, receive the ring map generation frame, they add their own node information to the received ring map generation frame and perform one-way (around the B system). Transmit to. When the node # 2, which is the B terminal, receives the ring map generation frame, the node # 2 completes the ring map by adding its own node information to the ring map described in the received ring map generation frame.

  As shown in FIG. 15B, the node # 2, which is the B terminal, further transmits a ring map transfer frame in which the completed ring map is described in the other direction (around the A system), A ring map may be held in some or all of the nodes. For example, when all other nodes hold the ring map, the node # 2, which is the B terminal station, transmits the ring map transfer frame in the other direction (around the A system) by multicast. When the intermediate stations (nodes # 3 to # 6) receive the ring map transfer frame, the intermediate stations store the ring map described in the received ring map transfer frame (for example, a storage unit (not shown) in the own node). The received ring map transfer frame is transferred in the other direction (around the A system). When the A terminal station (node # 1) receives the ring map transfer frame, the A terminal station (node # 1) stores the ring map described in the received ring map transfer frame inside (for example, a storage unit (not shown) in its own node).

  As shown in FIG. 15C, it is assumed that a failure has occurred between the node # 4 and the node # 5.

  As shown in FIG. 16D, the node # 4 transitions to the A terminal station, the nodes # 1 to # 3 and # 6 transition to the intermediate station, and the node # 5 transitions to the B terminal station. The state transition operation of each node is as described above with reference to FIGS. When the state of each node changes, node # 4, which is the A terminal station, generates, for example, a ring map generation frame every predetermined time, and adds the information of the own node to the generated ring map generation frame. Transmit in one direction (around system B). When nodes # 3, # 2, # 1, and # 6, which are intermediate stations, receive the ring map generation frame, they add their own node information to the received ring map generation frame and perform one-way (around B system) Transmit to. When node # 5, which is the B terminal, receives the ring map generation frame, it adds its own node information to the received ring map generation frame, and transmits the completed ring map to the inside of its node (for example, its own node). In a storage unit (not shown).

  As shown in FIG. 16 (e), the node # 5 which is the B terminal station further transmits another ring map transfer frame in which the completed ring map is described in the other direction (around the A system). A ring map may be held in some or all of the nodes. For example, when all other nodes hold the ring map, the node # 5, which is the B terminal station, transmits the ring map transfer frame in the other direction (around the A system) by multicast. When the intermediate stations (nodes # 1 to # 3 and # 6) receive the ring map transfer frame, the intermediate station internally stores the ring map described in the received ring map transfer frame (for example, not shown in the own node). The ring map transfer frame stored in the storage unit) is transferred in the other direction (around the A system). When the A terminal station (node # 4) receives the ring map transfer frame, the A terminal station (node # 4) stores the ring map described in the received ring map transfer frame inside (for example, a storage unit (not shown) in its own node).

  As in the example described above, the state of each node changes due to the occurrence of a failure, and the state of each node is dynamically determined. In this embodiment, in such a situation, the master node (A terminal station) generates a ring map generation frame, adds its own node information to the generated ring map generation frame, and transmits it around the B system. When the intermediate station node (intermediate station) receives the ring map generation frame from the adjacent node, it adds the information of the own node to the received ring map generation frame and transmits it around the B system. When the (end station) receives the ring map generation frame from the adjacent node, the ring map is completed by adding the information of the own node to the ring map described in the received ring map generation frame. This makes it possible to efficiently collect information on each node.

  Also, the functions of each of the port state control unit 13, the reception frame control unit 15, the transmission frame control unit 17, the network control unit 18, the ring map control unit 19 and the ring map holding unit 20 shown in FIG. The bidirectional double ring transmission line is also stored by storing this program in a computer-readable recording medium, and a CPU (Central Processing Unit) serving as a control center of each node sequentially reading and executing the program. A system and a frame transmission apparatus can be constructed.

It is a figure which shows the logical basic concept of the transmission-line system concerning embodiment of this invention. It is a figure which shows the kind of flame | frame transmitted / received in the transmission line system concerning this embodiment. It is a figure which shows the data format of the frame used with the transmission line system concerning this embodiment, (a) Inter-adjacent frame, (b) Network control frame, (c) User frame, each data format is shown. It is a block diagram which shows the internal structure of the data transmission apparatus concerning this embodiment. It is a figure which shows the physical fundamental structure of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of the failure generation of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of the failure generation of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of the failure recovery of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of the failure recovery of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of multiple loop integration of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of multiple loop integration of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of power activation of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the network control at the time of power activation of the transmission line system concerning this embodiment. It is a figure which shows the state transition between the modes of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the ring map production | generation and ring map transfer before the failure generation of the transmission line system concerning this embodiment. It is a figure which shows the procedure of the ring map production | generation and ring map transfer after the failure generation of the transmission line system concerning this embodiment.

Explanation of symbols

1-6 nodes (frame transmission equipment)
7, 8 Terminal 9, 10 Transmission path (A system, B system)
11 Port A (first port)
12 Port B (second port)
13 Port State Control Unit 14 Reception Buffer 15 Reception Frame Control Unit 16 Transmission Buffer 17 Transmission Frame Control Unit 18 Network Control Unit 19 Ring Map Control Unit 20 Ring Map Holding Unit

Claims (8)

A plurality of nodes are connected in a ring shape through transmission lines around the A system and the B system, and each of the plurality of nodes is
A master node capable of blocking transmission of frames around the A system and transmitting frames around the B system;
A terminal station node capable of transmitting a frame around the A system and terminating a transmission path of the frame around the B system;
Among the intermediate station nodes capable of transmitting frames around the A system and the B system,
A transmission line system dynamically determined by any one of the following:
The master node generates a ring map generation frame for generating a ring map, which is information relating to the plurality of nodes, and adds information on the own node to the generated ring map generation frame to Transmit to
When the intermediate station node receives a ring map generation frame from an adjacent node, it adds its own node information to the received ring map generation frame and transmits it around the B system.
When the terminal station node receives a ring map generation frame from an adjacent node, the terminal node node completes the ring map by adding information of the own node to the ring map described in the received ring map generation frame. A transmission line system. The terminal station node is
The transmission path system according to claim 1, wherein the ring map is transferred to another node by transmitting the completed ring map around the A system. The master node is
The ring map generation frame is generated at predetermined time intervals, and the node information is added to the generated ring map generation frame and transmitted around the B system. Item 3. The transmission line system according to Item 2. The plurality of nodes are:
The transmission path system according to any one of claims 1 to 3, wherein an address of the own node is used as the information of the own node. Some or all of the plurality of nodes are
The transmission path system according to any one of claims 1 to 4, wherein information of a computer connected to the own node is further added to the ring map generation frame. A plurality of nodes are connected in a ring shape through transmission lines around the A system and the B system, and each of the plurality of nodes is
A master node capable of blocking transmission of frames around the A system and transmitting frames around the B system;
A terminal station node capable of transmitting a frame around the A system and terminating a transmission path of the frame around the B system;
Among the intermediate station nodes capable of transmitting frames around the A system and the B system,
A ring map generation method in a transmission line system dynamically determined as any one of the following:
The master node generates a ring map generation frame for generating a ring map, which is information relating to the plurality of nodes, and adds information on the own node to the generated ring map generation frame to Transmit to
When the intermediate station node receives a ring map generation frame from an adjacent node, it adds its own node information to the received ring map generation frame and transmits it around the B system.
When the terminal station node receives a ring map generation frame from an adjacent node, the terminal node node completes the ring map by adding information of the own node to the ring map described in the received ring map generation frame. Ring map generation method. Multiple nodes are connected in a ring through transmission lines around A system and B system,
A master node capable of blocking transmission of frames around the A system and transmitting frames around the B system;
A terminal station node capable of transmitting a frame around the A system and terminating a transmission path of the frame around the B system;
Among the intermediate station nodes capable of transmitting frames around the A system and the B system,
A node that is dynamically determined to be one of them,
A first port and a second port for inputting and outputting information; a processing unit for processing information; and a storage unit for storing information;
The processor is
If the master node is determined, a ring map generation frame for generating a ring map that is information on a plurality of nodes is generated, and the information of the own node is added to the generated ring map generation frame And transmitted around the B system via the first port,
If it is determined to be the intermediate station node, when a ring map generation frame is received from an adjacent node via the second port, information of the own node is added to the received ring map generation frame. , Transmitted around the B system via the first port,
When it is determined as the terminal station node, when a ring map generation frame is received from an adjacent node via the second port, the local node is included in the ring map described in the received ring map generation frame. A node that completes a ring map by adding the information of and stores the completed ring map in the storage unit. The processor is
If it is determined as the terminal station node,
The node according to claim 7, wherein the ring map is transferred to another node by transmitting the completed ring map around the system A via the second port.

Images