JP6949255B2 - Control nodes, control methods, and control programs - Google Patents

Description

The present invention relates to control nodes, control methods, and control programs.

A spanning tree protocol may be used in a communication system constituting a plurality of nodes (see Non-Patent Document 1).

IEEE802.1D, [online], Internet <URL: https: // www. IEEE. org />

In a communication system in which the Spanning Tree Protocol is used, route selection is performed. In route selection, the route with the smallest total path cost is selected.
By the way, each of the plurality of nodes constituting the communication system may be connected by an optical fiber. Each of the plurality of nodes has a function of being able to continue optical communication even if a power failure occurs. This function is also called optical bypass.

When a power failure occurs in a node, the path cost related to the node is not included in the total value of the path costs used in the determination of route selection. Therefore, the total path cost of the route including the node may be the smallest value. Therefore, even if a power failure occurs in the node, the node performs optical bypass, so that optical communication is performed on the route including the node. Further, when the node performs optical bypass, the optical communication distance becomes long. When the optical communication distance becomes long, the optical signal deteriorates. Therefore, performing optical communication on a route including a node in which a power failure has occurred cannot realize highly reliable optical communication.

An object of the present invention is to realize highly reliable optical communication.

A control node according to one aspect of the present invention is provided. The optical communication system includes a control node and a plurality of nodes. In the optical communication system, optical communication is continued via one or more of the plurality of nodes in which the power supply is cut off. The control node is physically connected to the first node of the plurality of nodes by an optical fiber with a first port, and the second node of the plurality of nodes by an optical fiber. The power supply is cut off based on the second port connected to, the transmission / reception unit that receives an optical signal through at least one of the ports, and the optical signal received through the first port. Is generated, the path cost corresponding to the first port is calculated based on the path cost information which is the information used when calculating the path cost, and the path cost corresponding to the first port is calculated. It has a control unit that calculates a first pass cost by weighting with a weight, and calculates a second pass cost that is a pass cost corresponding to the second port based on the pass cost information. The transmission / reception unit transmits a configuration change notification from the plurality of nodes to one or more nodes receiving power supply obtained by excluding the one or more nodes in which the power is cut off, and receives the configuration change notification. From the one or more powered nodes, the path cost corresponding to each port of the one or more powered nodes is received. The control unit has the first pass cost among the first pass cost, the second pass cost, and the path cost corresponding to each port of the one or more nodes receiving power supply. When is the largest value, optical communication via the first port is restricted.

According to the present invention, highly reliable optical communication can be realized.

It is a figure which shows the optical communication system of Embodiment 1. It is a figure which shows the hardware structure which the node of Embodiment 1 has. It is a functional block diagram which shows the structure of the node of Embodiment 1. FIG. It is a figure which shows the example of the path cost table of Embodiment 1. FIG. It is a figure which shows the specific example when the power-off occurs in the node of Embodiment 1. FIG. It is a figure (the 1) which shows the example of the sequence of the setting process of the non-designated port of Embodiment 1. FIG. It is a figure (the 2) which shows the example of the sequence of the setting process of the non-designated port of Embodiment 1. FIG. It is a figure which shows the optical communication system of Embodiment 2. It is a functional block diagram which shows the structure of the node of Embodiment 2. FIG.

Hereinafter, embodiments will be described with reference to the drawings. The following embodiments are merely examples, and various modifications can be made within the scope of the present invention.

Embodiment 1.
FIG. 1 is a diagram showing an optical communication system according to the first embodiment. The optical communication system includes nodes 101 to 107 and a root node 200. Further, the optical communication system may include the server group 300.

The optical communication system may be expressed as follows. The optical communication system includes a control node and a plurality of nodes. The control node is one of the nodes 101 to 107. For example, node 104 is a control node. When the node 104 is a control node, the plurality of nodes are nodes 101-103, 105-107 and root node 200. Here, the control node executes the control method.

The optical communication system constructs a ring network starting from the root node 200. The spanning tree protocol is used in the optical communication system. The Spanning Tree Protocol is standardized in IEEE802.1D.
The nodes 101 to 107 are connected by an optical fiber. For example, the node 101 and the node 102 are connected by an optical fiber. Further, the node 101 and the root node 200 are connected by an optical fiber. Further, the node 107 and the root node 200 are connected by an optical fiber. The link speed between the nodes is assumed to be 1 Gbps.
For example, the root node 200 and the server group 300 are connected by a LAN (Local Area Network) cable.

The nodes 101 to 107 and the root node 200 transmit and receive BPDU (Bridge Protocol Data Unit) frames. The BPDU frame contains information managed by each node.
Nodes 101 to 107 calculate a virtual distance from the root node 200 to its own node. The virtual distance is also called the path cost. The nodes 101 to 107 and the server group 300 communicate with each other on the route having the smallest total path cost.

It is assumed that a non-designated port is set for the port 10 of the node 104. In the optical communication system, the loop of the multicast frame or the broadcast frame is prevented by setting the non-designated port.

In the optical communication system, optical communication is continued via one or more nodes in which the power supply is cut off among the plurality of nodes. For example, when the node 104 is a control node, in the optical communication system, optical communication is continued via one or more of the nodes 101-103, 105-107 and the root node 200 in which the power supply is cut off.

Next, the hardware included in the node 104 will be described.
FIG. 2 is a diagram showing a hardware configuration of the node of the first embodiment. Node 104 includes a processor 11, a volatile storage device 12, and a non-volatile storage device 13.

The processor 11 controls the entire node 104. For example, the processor 11 is a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), or the like. The processor 11 may be a multiprocessor. The node 104 may be realized by a processing circuit, or may be realized by software, firmware, or a combination thereof. The processing circuit may be a single circuit or a composite circuit.

The volatile storage device 12 is the main storage device of the node 104. For example, the volatile storage device 12 is a RAM (Random Access Memory). The non-volatile storage device 13 is an auxiliary storage device of the node 104. For example, the non-volatile storage device 13 is an SSD (Solid State Drive).
Further, the volatile storage device 12 or the non-volatile storage device 13 is also referred to as a storage unit.
Nodes 101-103, 105-107 and root node 200, like node 104, have a processor, a volatile storage device, and a non-volatile storage device.

Next, the functional blocks of the nodes will be described. The functional block included in the node 104 and the functional block included in the nodes 101-103 and 105-107 are the same. Therefore, in FIG. 3, the functional block included in the node 104 will be described. The description of the functional blocks included in the nodes 101 to 103 and 105 to 107 will be omitted.

FIG. 3 is a functional block diagram showing the configuration of the node of the first embodiment. The node 104 has ports 104a and 104b, intensity measuring units 104c and 104d, an optical bypass unit 104e, a transmission / reception unit 104f, and a control unit 104g.
The port 104a is physically connected to the node 103 by an optical fiber. Here, for example, port 104a is also referred to as a first port. Further, for example, the node 103 is also referred to as a first node.

The port 104b is physically connected to the node 105 by an optical fiber. Here, for example, the port 104b is also referred to as a second port. Further, for example, the node 105 is also referred to as a second node.
When port 104b is a non-designated port, communication between node 104 and node 105 is restricted. The transmission / reception unit 104f may receive a BPDU frame from the node 105 via the port 104b. Further, the port 10 in FIG. 1 is the port 104b.

The strength measuring unit 104c and the strength measuring unit 104d may be considered as DDM (Digital Diagnostic Monitoring).
The transmission / reception unit 104f and the control unit 104g may be included in one housing.
A part or all of the transmission / reception unit 104f and the control unit 104g may be realized by the processor 11. Further, a part or all of the transmission / reception unit 104f and the control unit 104g may be realized as a module of a program executed by the processor 11. For example, the program executed by the processor 11 is also called a control program. For example, the control program is stored in a recording medium such as the volatile storage device 12 and the non-volatile storage device 13.

The intensity measuring unit 104c measures the intensity of the optical signal received via the port 104a. The intensity measuring unit 104d measures the intensity of the optical signal received via the port 104b. Here, the intensity of the optical signal may be expressed as the power of the optical signal.
The optical bypass unit 104e switches to the bypass mode when a power failure occurs in the node 104. The bypass mode is a mode in which an optical signal is reflected and transferred to another port. In this way, in the optical communication system, optical communication can be continued even if a power failure occurs in the node.

The transmission / reception unit 104f receives an optical signal via at least one or more of the ports 104a and 104b.
The transmission / reception unit 104f receives the optical signal input to the node 104. For example, the transmission / reception unit 104f receives the optical signal via the optical bypass unit 104e. Further, for example, the transmission / reception unit 104f receives the optical signal without going through the optical bypass unit 104e. When the optical bypass unit 104e is in the bypass mode, the transmission / reception unit 104f cannot receive the optical signal input to the node 104.

The transmission / reception unit 104f has an O (Optical) / E (Electrical) conversion function. In addition, the transmission / reception unit 104f periodically transmits / receives BPDU frames. The BPDU frame includes the path cost.
The path cost is calculated by the control unit 104g. The control unit 104g uses a path cost table when calculating the path cost. That is, the path cost table is information used when calculating the path cost. A specific example of the path cost table is shown.

FIG. 4 is a diagram showing an example of the path cost table of the first embodiment. For example, the path cost table 400 is stored in the volatile storage device 12 or the non-volatile storage device 13. The path cost table 400 is also referred to as path cost information.
The path cost table 400 has items for link speed and cost. The link speed may be expressed as a band. The cost items in the path cost table 400 include multiple costs, each with a different value.

The control unit 104g can calculate the path cost corresponding to the port 104a based on the path cost table 400. Further, the control unit 104g can calculate the path cost corresponding to the port 104b based on the path cost table 400.
Further, the control unit 104g weights the path cost with a weight. For example, the control unit 104g adds a weight to the path cost. The weight is calculated based on the equation (1).

Weight = N x M x degree of disability ... (1)

N is the number of nodes existing between the port and the root node 200. For example, the Message Age included in the BPDU frame is used to count the number of nodes. In the Message Age, the value is added by 1 each time the BPDU frame passes through the node.
M is the maximum value among the plurality of costs registered in the path cost table 400. For example, M is 100.

The degree of failure is the degree of failure in optical communication caused by a power failure. For example, the degree of failure is determined based on the intensity of the optical signal measured by the intensity measuring unit 104c or the intensity measuring unit 104d. When the intensity of the optical signal is equal to or higher than the first threshold value, the control unit 104g sets the degree of failure to 0. In addition, when the degree of failure is 0, it means that no failure has occurred. If the degree of failure is 0, the weight will be 0. When the weight is 0, it can be said that the path cost is not weighted.

Further, the control unit 104g sets the degree of failure to 1 when the intensity of the optical signal is less than the first threshold value and equal to or higher than the second threshold value. For example, the control unit 104g sets the degree of failure to 1 when the intensity of the optical signal received via the port 104a is less than the first threshold value and equal to or higher than the second threshold value. The second threshold value is smaller than the first threshold value. A failure degree of 1 means that the Warning threshold is exceeded. The value "1" set for the degree of disability is also referred to as the first value.

Further, the control unit 104g sets the degree of failure to 2 when the intensity of the optical signal is less than the second threshold value. For example, the control unit 104g sets the degree of failure to 2 when the intensity of the optical signal received via the port 104a is less than the second threshold value. A failure degree of 2 means that the Allarm is exceeded. The value "2" set for the degree of disability is also referred to as a second value. The control unit 104g can reflect the serious degree in the path cost by reflecting the value according to the degree of failure in the weight.

In this way, the control unit 104g calculates the weight based on the equation (1). Then, the control unit 104g weights the path cost with a weight. The weighting of the path cost is intended to increase the path cost. Therefore, the control unit 104g may multiply the path cost by the weight.

Next, the processing of the node 104 when a power failure occurs in the adjacent node will be described. For example, the adjacent node is node 103.
The control unit 104g detects that a power failure has occurred based on an optical signal received via the port 104a. The detection method will be described in detail later. The control unit 104g calculates the path cost corresponding to the port 104a based on the path cost table 400. The control unit 104g calculates a new path cost by weighting the path cost corresponding to the port 104a with a weight. For example, the new pass cost is also referred to as the first pass cost. The control unit 104g calculates the second path cost, which is the path cost corresponding to the port 104b, based on the path cost table 400.

The transmission / reception unit 104f transmits a configuration change notification to one or more nodes receiving power supply obtained by excluding the node in which the power is cut off from the plurality of nodes. The transmission / reception unit 104f receives the path cost corresponding to each port of the one or more power-supplied nodes from the one or more power-supplied nodes that have received the configuration change notification.

The control unit 104g has the highest value among the first pass cost, the second pass cost, and the path cost corresponding to each port of one or more nodes receiving power supply. If, the optical communication via the port 104a is restricted. Moreover, this sentence may be expressed as follows. The control unit 104g has the highest value among the first pass cost, the second pass cost, and the path cost corresponding to each port of one or more nodes receiving power supply. If, the port 104a is set as a non-designated port.

FIG. 5 is a diagram showing a specific example when a power failure occurs in the node of the first embodiment. FIG. 5 shows that a power failure has occurred at the node 102 and the node 103. Node 102 and node 103 are in bypass mode. Therefore, the node 101 and the node 104 are in a state where the optical fiber is directly connected.

Next, the setting process of the non-designated port will be described using a sequence.
FIG. 6 is a diagram (No. 1) showing an example of a sequence of setting processing of the non-designated port of the first embodiment.
(Step S101) A power failure occurs at the node 102 and the node 103.

(Step S102) Node 105 transmits an optical signal including a BPDU frame.
(Step S103) Node 101 transmits an optical signal including a BPDU frame.
(Step S104) The control unit 104g of the node 104 detects that a power failure has occurred based on the optical signal received via the port 104a.

For example, the control unit 104g of the node 104 detects that a power failure has occurred based on the BPDU frame included in the optical signal. This will be described in detail. First, the BPDU frame contains a MAC (Media Access Control) address. Before the power failure occurs, the transmission / reception unit 104f of the node 104 receives the BPDU frame including the MAC address of the node 103. After the power failure occurs, the transmission / reception unit 104f of the node 104 receives the BPDU frame including the MAC address of the node 101. As a result, the control unit 104g of the node 104 detects that the power failure has occurred at the nodes 102 and 103 due to the change of the MAC address of the transmission source.

Further, for example, the control unit 104g of the node 104 detects that the power supply is cut off at the nodes 102 and 103 when the intensity of the optical signal measured by the intensity measuring unit 104c is equal to or less than a preset threshold value.

Further, for example, the control unit 104g of the node 104 detects that a power failure has occurred based on the Message Age of the BPDU frame. This will be described in detail. The control unit 104g of the node 104 detects that the power failure has occurred in the nodes 102 and 103 by comparing the Message Age before the power failure occurs with the Message Age after the power failure occurs.

(Step S105) The control unit 104g of the node 104 calculates the path cost corresponding to the port 104a based on the path cost table 400. For example, the link speed between the node 101 and the root node 200 is 1 Gbps. The link speed between node 101 and node 104 is 1 Gbps. Therefore, the control unit 104g of the node 104 calculates 8 (= 4 + 4), which is the path cost corresponding to the port 104a.

The control unit 104g of the node 104 calculates the weight. For example, the control unit 104g of the node 104 acquires the number of nodes existing between the port 104a and the root node 200 from the Message Age of the BPDU frame. The number of nodes is 1. Here, it is assumed that the intensity of the optical signal measured by the intensity measuring unit 104c of the node 104 is less than the first threshold value and equal to or more than the second threshold value. The control unit 104g of the node 104 sets the degree of failure to 1. The control unit 104g of the node 104 calculates the weight based on the equation (1). The weight is 400 (= 1 × 100 × 1).

The control unit 104g of the node 104 adds a weight to the path cost. The pass cost is 408 (= 8 + 400). The pass cost is the first pass cost. Hereinafter, the first path cost will be described as the path cost corresponding to the port 104a.

Here, the maximum value of the path cost is used for calculating the weight. The reason for using the maximum path cost will be explained. For example, assume that the link speed of a part of the route from the node 105 to the root node 200 is 10 Mbps. In this case, the total value of the path costs in the routes of the nodes 101 to 104 may be smaller than the total value of the path costs in the routes of the nodes 105 to 107. The optical communication system wants to increase the total value of the path costs in the routes of the nodes 101 to 104 in order to suppress the communication of the route including the node in which the power supply is cut off. Therefore, the maximum value of the path cost is used to calculate the weight.

The control unit 104g of the node 104 calculates the path cost corresponding to the port 104b based on the path cost table 400. For example, the link speed between node 104 and node 105 is 1 Gbps. The link speed between node 105 and node 106 is 1 Gbps. The link speed between node 106 and node 107 is 1 Gbps. The link speed between node 107 and root node 200 is 1 Gbps. Therefore, the control unit 104g of the node 104 calculates 16 (= 4 × 4), which is the path cost corresponding to the port 104b.

Since the power supply is not cut off at the node 105, the intensity of the optical signal measured by the intensity measuring unit 104d of the node 104 is equal to or higher than the first threshold value. Therefore, the control unit 104g of the node 104 sets the degree of failure to 0. As a result, the weight becomes 0. Therefore, the path cost corresponding to port 104b is not weighted. The intensity measuring unit 104d of the node 104 can measure the intensity of the optical signal based on the optical signal including the BPDU frame transmitted by the node 105 in step S102.

(Step S106) The transmission / reception unit 104f of the node 104 transmits a BPDU frame including the path cost corresponding to the port 104a and the path cost corresponding to the port 104b to the node 101. The BPDU frame is also referred to as a configuration change notification. Further, the BPDU frame is transmitted as an optical signal.

(Step S107) The control unit of the node 101 detects that a power failure has occurred in the node 102 and the node 103. The detection method is as described above.
(Step S108) The control unit of the node 101 calculates the path cost corresponding to the two ports of the node 101. The control unit of the node 101 adds a weight to the path cost corresponding to the port connected to the node 104 among the two ports. The weight is calculated by the control unit of the node 101 using the equation (1).
Here, the processing after step S108 may be considered to be executed based on the spanning tree protocol.

FIG. 7 is a diagram (No. 2) showing an example of a sequence of setting processing of the non-designated port of the first embodiment.
(Step S111) The transmission / reception unit 104f of the node 104 transmits a BPDU frame including the path cost corresponding to the port 104a and the path cost corresponding to the port 104b to the node 105. The BPDU frame is also referred to as a configuration change notification. Further, the BPDU frame is transmitted as an optical signal.

(Step S112) The transmission / reception unit 104f of the node 104 transmits a BPDU frame including the path cost corresponding to the port 104a and the path cost corresponding to the port 104b to the node 106. The BPDU frame is also referred to as a configuration change notification. Further, the BPDU frame is transmitted as an optical signal.

(Step S113) The transmission / reception unit 104f of the node 104 transmits a BPDU frame including the path cost corresponding to the port 104a and the path cost corresponding to the port 104b to the node 107. The BPDU frame is also referred to as a configuration change notification. Further, the BPDU frame is transmitted as an optical signal.

(Step S114) The transmission / reception unit 104f of the node 104 transmits a BPDU frame including the path cost corresponding to the port 104a and the path cost corresponding to the port 104b to the root node 200. The BPDU frame is also referred to as a configuration change notification. Further, the BPDU frame is transmitted as an optical signal.

In this way, the transmission / reception unit 104f of the node 104 transmits the BPDU frame to the nodes 101, 105-107 and the root node 200 that are receiving power supply. However, the transmission / reception unit 104f of the node 104 does not transmit the BPDU frame to the nodes 102 and 103.

The transmission / reception unit 104f of the node 104 transmits a BPDU frame including a path cost corresponding to the port 104a and a path cost corresponding to the port 104b. However, the transmission / reception unit 104f of the node 104 may transmit two BPDU frames, a BPDU frame including a path cost corresponding to the port 104a and a BPDU frame including a path cost corresponding to the port 104b.

(Step S115) The transmission / reception unit of the node 101 transmits a BPDU frame including the path cost corresponding to the two ports of the node 101 to the node 104. Further, the BPDU frame is transmitted as an optical signal.
(Step S116) The transmission / reception unit of the node 105 transmits a BPDU frame including the path cost corresponding to the two ports of the node 105 to the node 104. Further, the BPDU frame is transmitted as an optical signal.

(Step S117) The transmission / reception unit of the node 106 transmits a BPDU frame including the path cost corresponding to the two ports of the node 106 to the node 104. Further, the BPDU frame is transmitted as an optical signal.
(Step S118) The transmission / reception unit of the node 107 transmits a BPDU frame including the path cost corresponding to the two ports of the node 107 to the node 104. Further, the BPDU frame is transmitted as an optical signal.

(Step S119) The root node 200 transmits a BPDU frame including the path cost corresponding to the two ports of the root node 200 to the node 104. Further, the BPDU frame is transmitted as an optical signal.
As a result, the transmission / reception unit 104f of the node 104 acquires the path cost corresponding to the port from the nodes 101, 105 to 107 that received the BPDU frame and the root node 200.

Further, like the node 104, the node 101 transmits a BPDU frame including a path cost corresponding to the two ports of the node 101 to all the nodes included in the network. However, the node 101 does not transmit the BPDU frame to the nodes 102 and 103. The transmission process of the node 101 is not shown. The BPDU frame transmitted by the node 101 is also referred to as a configuration change notification.

The node 101, like the node 104, acquires the path cost corresponding to the ports of all the nodes included in the network. The acquisition is omitted from the illustration. However, the transmission / reception unit of the node 101 does not receive the path cost corresponding to the ports of the nodes 102 and 103.

Further, the nodes 105, 106, 107 and the root node 200 transmit the BPDU frame including the path cost corresponding to the two ports of the own node to all the nodes included in the network, similarly to the node 104. However, the BPDU frame is not transmitted to the nodes 102 and 103. The transmission processing of the nodes 105, 106, 107 and the root node 200 is not shown.

The nodes 105, 106, 107 and the root node 200, like the node 104, acquire the path costs corresponding to the ports of all the nodes included in the network. The acquisition is omitted from the illustration. Nodes 105, 106, 107 and root node 200 do not receive the path cost corresponding to the ports of nodes 102, 103.

(Step S120) The control unit 104g of the node 104 among the path cost corresponding to the port 104a, the path cost corresponding to the port 104b, and the path cost acquired from the nodes 101, 105, 106, 107 and the root node 200, is the port. If the path cost corresponding to 104a is the largest value, port 104a is set as a non-designated port.

In the examples of FIGS. 6 and 7, among the path cost corresponding to the port 104a, the path cost corresponding to the port 104b, and the path cost acquired from the nodes 101, 105, 106, 107 and the root node 200, the port 104a is supported. The value to be passed is the largest. The control unit 104g of the node 104 sets the port 104a as a non-designated port.

Further, the nodes 101, 105, 106, 107 and the root node 200 determine whether or not to set the port of the own device as the non-designated port, similarly to the node 104. In the examples of FIGS. 6 and 7, the path cost corresponding to the port 104a is the largest value. Therefore, no non-designated port is set for the ports of the nodes 101, 105, 106, 107 and the root node 200.

Performing the setting process of the non-designated port in the nodes 101, 104 to 107 and the root node 200 means setting the non-designated port again because the power supply is cut off in the nodes 102 and 103.

FIG. 5 shows that port 20 of node 104 is set as a non-designated port. Further, the port 20 is the port 104a. As a result, communication between node 101 and node 104 is restricted. Then, the node 104 communicates with the server group 300 via the nodes 105, 106, 107 and the root node 200.

According to the first embodiment, the node 104 cancels the optical communication by the route including the nodes 102 and 103 by setting the port 104a as a non-designated port. When the power supply is cut off at the nodes 102 and 103, the intensity of the optical signal received from the node 105 is higher than the intensity of the optical signal received from the node 101. Therefore, the node 104 can realize highly reliable optical communication by performing optical communication on the path via the node 105.

In the above, the case where the port 104a is set as the non-designated port when the power supply is cut off at the nodes 102 and 103 has been described. Further, if the method of the first embodiment is used, the following can occur. For example, when the power of the node 102 is cut off, the port connected to the node 101 out of the two ports of the node 103 is set as the non-designated port. In this case, the node 103 may be considered as a control node. Then, the plurality of nodes may be considered as nodes 101, 102, 104 to 107 and the root node 200.

The number of ports possessed by each node included in the optical communication system of the first embodiment may be three or more. For example, node 104 further has a plurality of ports. The plurality of ports are physically connected to the first plurality of nodes obtained by removing the node 103 and the node 105 from the nodes 101 to 103, 105 to 107 and the root node 200 by a plurality of optical fibers.

When the node 104 has a plurality of ports, the node 104 executes the following control. The transmission / reception unit 104f receives information based on an optical signal via the port 104a, the port 104b, and at least one or more of the plurality of ports. The control unit 104g further calculates a plurality of path costs corresponding to the plurality of ports based on the path cost table 400. The control unit 104g corresponds to the path cost corresponding to the port 104a (that is, the first path cost), the path cost corresponding to the port 104b, the plurality of path costs, and each port of one or more nodes having power supply. When the path cost corresponding to the port 104a (that is, the first path cost) is the largest value among the path costs to be performed, the optical communication via the port 104a is restricted.

Embodiment 2.
Next, the second embodiment will be described. In the second embodiment, the matters different from the first embodiment will be mainly described, and the description of the matters common to the first embodiment will be omitted. The second embodiment refers to FIGS. 1 to 7.
In the first embodiment, the case where the optical communication system constructs a ring network has been described. In the second embodiment, a case where the optical communication system constructs a network other than the ring network will be described.

FIG. 8 is a diagram showing the optical communication system of the second embodiment. The optical communication system includes nodes 101a, 102a, 103-105, 106a, 107a, 108, 109 and a root node 200.

First, the functional blocks included in the nodes 101a, 102a, 106a, 107a, 108, 109 will be described. The functional block included in the node 102a and the functional block included in the nodes 101a, 106a, 107a, 108, 109 are the same. Therefore, in FIG. 9, the functional block included in the node 102a will be described. The description of the functional blocks included in the nodes 101a, 106a, 107a, 108, 109 will be omitted.

FIG. 9 is a functional block diagram showing the configuration of the node of the second embodiment. The node 102a has ports 102aa, 102ab, 102ah, intensity measuring units 102ac, 102ad, optical bypass unit 102ae, transmission / reception unit 102af, control unit 102ag, and SFP (Small Form-factory Pluggable) 102ai.
The port 102aa is physically connected to the node 101 by an optical fiber. Here, for example, the port 102aa is also referred to as a second port. Further, for example, the node 101 is also referred to as a second node.

The port 102ab is physically connected to the node 103 by an optical fiber. Here, for example, the port 102ab is also referred to as a first port. Further, for example, the node 103 is also referred to as a first node.
The port 102ah is physically connected to the node 108 by an optical fiber. Here, for example, the port 102ah is also referred to as a third port. Further, for example, the node 108 is also referred to as a third node.

The transmission / reception unit 102af and the control unit 102ag may be included in one housing.
The SFP102ai has a strength measuring unit 102ai1. The strength measuring unit 102ai1 may be considered as a DDM.

A part or all of the transmission / reception unit 102af and the control unit 102ag may be realized by the processor included in the node 102a. Further, a part or all of the transmission / reception unit 102af and the control unit 102ag may be realized as a module of a program executed by the processor included in the node 102a. For example, the program executed by the processor is also called a control program.

The strength measuring units 102ac and 102ad have the same functions as the strength measuring units 104c and 104d. Therefore, the description of the strength measuring units 102ac and 102ad will be omitted.
The optical bypass unit 102ae has the same function as the optical bypass unit 104e. Therefore, the description of the optical bypass unit 102ae will be omitted.

The transmission / reception unit 102af has the same function as the transmission / reception unit 104f. Therefore, the description of the same function will be omitted. Further, the transmission / reception unit 102af receives information based on an optical signal via at least one or more of the ports 102aa, 102ab, and 102ah.
The control unit 102ag has the same function as the control unit 104g. Therefore, the description of the same function will be omitted.

The intensity measuring unit 102ai1 measures the intensity of the optical signal received via the port 102ah. Here, the control unit 102ag can acquire the intensity of the optical signal measured by the intensity measuring units 102ac, 102ad, 102ai1. In FIG. 9, the connecting line between the control unit 102ag and the strength measuring unit 102ac, 102ad, 102ai1 is omitted.

FIG. 8 shows a case where the power supply is cut off at the nodes 102a and 103. As described in the first embodiment, after the power failure occurs at the nodes 102a and 103, the path cost is calculated at all the nodes except the nodes 102a and 103. Then, a non-designated port is set for the port having the highest path cost. FIG. 8 shows that the non-designated port is set to port 20 of node 104. The port 20 is the port 104a.

According to the second embodiment, the node 104 cancels the optical communication by the route including the nodes 102a and 103 by setting the port 104a as a non-designated port. When the power supply is cut off at the nodes 102a and 103, the intensity of the optical signal received from the node 105 is higher than the intensity of the optical signal received from the node 101. Therefore, the node 104 can realize highly reliable optical communication by performing optical communication on the path via the node 105.

Further, if the method of the second embodiment is used, the following can occur. For example, when a power failure occurs in the node 103, the port 102ab is set as a non-designated port. In this case, the node 102a may be considered as a control node. The case where the port 102ab included in the node 102a is set as the non-designated port will be described. The control unit 102ag detects that a power failure has occurred based on an optical signal received via the port 102ab. The control unit 102ag calculates the path cost corresponding to the port 102ab based on the path cost table 400. The control unit 102ag calculates a new path cost by weighting the path cost corresponding to the port 102ab with a weight. For example, the new pass cost is also referred to as the first pass cost. The control unit 102ag calculates the path cost corresponding to the port 102aa based on the path cost table 400. For example, the pass cost is also referred to as a second pass cost. The control unit 102ag calculates the path cost corresponding to the port 102ah based on the path cost table 400. For example, the pass cost is also referred to as a third pass cost. The transmission / reception unit 102af transmits a configuration change notification to one or more nodes having power supply. The transmitter / receiver 102af receives the path cost corresponding to each port of one or more powered nodes. The control unit 102ag has a first pass cost among the first pass cost, the second pass cost, the third pass cost, and the path cost corresponding to each port of one or more nodes having power supply. When is the largest value, the optical communication via the port 102ab is restricted. That is, the control unit 102ag is the first of the first pass cost, the second pass cost, the third pass cost, and the pass cost corresponding to each port of one or more nodes having power supply. If the path cost is the highest value, port 102ab is set as a non-designated port.

As described above, the optical communication system of the second embodiment can realize highly reliable optical communication even when a network other than the ring network is constructed.

The spanning tree protocol is used in the optical communication systems of the first and second embodiments. However, in the optical communication systems of the first and second embodiments, the rapid spanning tree protocol or the multiple spanning tree protocol may be used.

The features of each of the embodiments described above can be combined with each other as appropriate.

10, 20 ports, 11 processors, 12 volatile storage devices, 13 non-volatile storage devices, 101-109 nodes, 101a, 102a, 106a, 107a nodes, 102aa, 102ab, 102ah ports, 102ac, 102ad, 102ai1 strength measuring unit, 102ae optical bypass unit, 102af transmission / reception unit, 102ag control unit, 102ai SFP, 104a, 104b port, 104c, 104d intensity measurement unit, 104e optical bypass unit, 104f transmission / reception unit, 104g control unit, 200 route node, 300 server group, 400 Path cost table.

Claims (7)

A control node in an optical communication system that includes a control node and a plurality of nodes, and in which optical communication is continued via one or more nodes in which a power failure occurs among the plurality of nodes.
The first port physically connected to the first node of the plurality of nodes by an optical fiber and the second node of the plurality of nodes are physically connected by an optical fiber. A second port, a transmitter / receiver that receives an optical signal through at least one of the ports, and a transmitter / receiver.
The first port is based on path cost information, which is information used when detecting that a power failure has occurred based on an optical signal received via the first port and calculating a path cost. The first path cost is calculated by calculating the path cost corresponding to the first port and weighting the path cost corresponding to the first port with a weight, and corresponding to the second port based on the path cost information. A control unit that calculates the second pass cost, which is the pass cost,
Have,
The transmission / reception unit transmits a configuration change notification from the plurality of nodes to one or more nodes receiving power supply obtained by excluding the one or more nodes in which the power is cut off, and receives the configuration change notification. Receive the path cost corresponding to each port of the powered one or more nodes from the powered one or more nodes.
The control unit has the first pass cost among the first pass cost, the second pass cost, and the path cost corresponding to each port of the one or more nodes receiving power supply. When is the largest value, the optical communication via the first port is restricted.
Control node. The transmission / reception unit is at least one of the first port, the second port, and a third port physically connected to the third node of the plurality of nodes by an optical fiber. Receives information based on optical signals through the port of
The control unit calculates a third pass cost, which is a pass cost corresponding to the third port, based on the path cost information, and the first pass cost, the second pass cost, and the third pass cost. When the first path cost is the largest value among the path cost of the above and the path cost corresponding to each port of one or more nodes having the power supply, optical communication via the first port is performed. To limit
The control node according to claim 1. The transmission / reception unit is a first plurality of nodes and a plurality of optical fibers obtained by excluding the first node and the second node from the first port, the second port, and the plurality of nodes. Receives information based on optical signals through at least one or more of the multiple ports physically connected in
The control unit calculates a plurality of path costs corresponding to the plurality of ports based on the path cost information, and the first path cost, the second path cost, the plurality of path costs, and the power supply. When the first path cost is the largest value among the path costs corresponding to each port of one or more supplied nodes, the optical communication through the first port is restricted.
The control node according to claim 1. The plurality of nodes include a root node.
The path cost information includes a plurality of costs having different values.
The control unit determines the number of nodes existing between the first port and the root node, the maximum value among the plurality of costs, and the degree of failure, which is the degree of failure in optical communication caused by the power failure. Based on, the weight is calculated,
The control node according to any one of claims 1 to 3. When the intensity of the optical signal received through the first port is less than the first threshold value and is equal to or higher than the second threshold value, which is a value smaller than the first threshold value, the control unit has a second threshold value. A value of 1 is set for the degree of failure, and when the intensity is less than the second threshold value, a second value, which is a value larger than the first value, is set for the degree of failure.
The control node according to claim 4. The control node in an optical communication system including a control node and a plurality of nodes, and among the plurality of nodes, in which optical communication is continued via one or more nodes in which a power failure has occurred, is the control node.
The first port physically connected to the first node of the plurality of nodes by an optical fiber and the second node of the plurality of nodes are physically connected by an optical fiber. Receives an optical signal through a second port and at least one of the ports,
It is detected that the power failure has occurred based on the optical signal received through the first port, and the power is cut off.
The path cost corresponding to the first port is calculated based on the path cost information which is the information used when calculating the path cost, and the path cost corresponding to the first port is weighted by a weight. The path cost of 1 is calculated, and the second pass cost, which is the path cost corresponding to the second port, is calculated based on the path cost information.
A configuration change notification is transmitted from the plurality of nodes to one or more nodes receiving power supply obtained by excluding the one or more nodes in which the power is cut off.
The path cost corresponding to each port of the one or more power-supplied nodes is received from the one or more power-supplied nodes that have received the configuration change notification.
Among the first pass cost, the second pass cost, and the pass cost corresponding to each port of the one or more nodes receiving power supply, the first pass cost is the highest value. If there is, the optical communication via the first port is restricted.
Control method. The control node in the optical communication system including a control node and a plurality of nodes, and of which the optical communication is continued via one or more nodes in which the power supply is cut off, among the plurality of nodes.
The first port physically connected to the first node of the plurality of nodes by an optical fiber and the second node of the plurality of nodes are physically connected by an optical fiber. Receives an optical signal through a second port and at least one of the ports,
It is detected that the power failure has occurred based on the optical signal received through the first port, and the power is cut off.
The path cost corresponding to the first port is calculated based on the path cost information which is the information used when calculating the path cost, and the path cost corresponding to the first port is weighted by a weight. The path cost of 1 is calculated, and the second pass cost, which is the path cost corresponding to the second port, is calculated based on the path cost information.
A configuration change notification is transmitted from the plurality of nodes to one or more nodes receiving power supply obtained by excluding the one or more nodes in which the power is cut off.
The path cost corresponding to each port of the one or more power-supplied nodes is received from the one or more power-supplied nodes that have received the configuration change notification.
Among the first pass cost, the second pass cost, and the pass cost corresponding to each port of the one or more nodes receiving power supply, the first pass cost is the highest value. If there is, the optical communication via the first port is restricted.
A control program that executes processing.

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