JPH1174920A - Connection switching method, device therefor and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable fast connection switching even when a multiple failure occurs and also to easily grasp the flow of switching control by storing connection destination information that shows the connection state of a switch that corresponds to the kind of a failure and changing connection states of the switch based on read connection destination information. SOLUTION: This device stores connection destination information that shows the connection state of a switch that corresponds to the kind of a failure and changes the connection state of a switch based on read connection destination information. That is, connection destination information of each failure is defined in each image number, a connection destination table 107a and a normal connection destination table 107b are preliminarily produced by aggregating connection destination information of each failure, and the information is stored in a connection information table 107. Then, a processor 106 can specify the table 107a only by deciding the kind of a failure, specify an output point that corresponds to an input point in which the failure occurs from the table 107b and specify the input point of a switching destination from that.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to connection switching in nodes constituting a network, and more particularly to a connection switching method and apparatus when a failure occurs, and a storage medium.

[0002]

2. Description of the Related Art Generally, in a ring network in which a plurality of nodes are connected in a loop, a signal identical to a normal transmission signal is transmitted in the same direction as a spare signal.
When a failure occurs in a normal line between certain nodes, the connection is switched to a protection line in those nodes to avoid signal interruption. Such connection switching
This is performed by a switch provided in the node, for example, a cross-connect device.

[0003]

However, the conventional cross-connect switching control is described by a program on firmware. Whenever a failure occurs and the connection needs to be switched, the program is started. It was necessary to calculate the connection switching destination. In particular, when a plurality of faults occur multiple times, the program is executed for each fault, so it takes time to complete the connection, and the connection cannot be switched at high speed. In addition, there was a case where a transient connection exists.

Further, in addition to the need for a number of programs corresponding to the type of fault, if a fault occurs multiple times, the program repeats branching and recursion, making it extremely difficult to grasp the control flow on a desk. For this reason, there is also a problem that the possibility that the program on the firmware contains a bug increases.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a connection switching method and apparatus which can complete connection switching at high speed, and a storage medium. It is another object of the present invention to provide a connection switching method and apparatus and a storage medium that can achieve high-speed connection switching even when multiple failures occur. Another object of the present invention is to provide a connection switching method and apparatus and a storage medium that can easily grasp the flow of switching control even when multiple failures occur.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, a connection switching method, apparatus and storage medium according to the present invention define the type of a fault that occurs in an input line and respond to the type of a fault. Stores connection destination information indicating the connection status of the switch, and if a failure occurs in the input line,
Identify the type of failure based on the type of failure defined, read connection destination information corresponding to the identified type of failure,
The connection state of the switch is switched based on the read connection destination information.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram schematically illustrating a ring network according to an embodiment of the present invention. For the sake of simplicity, a ring network in which five nodes N1 to N5 having the same configuration are connected in a loop is assumed.
These nodes N1 to N5 are connected by a clockwise line W1 and a spare line S1, and a counterclockwise line W2 and a spare line S2.

As will be described later, each of the nodes N1 to N5 is provided with a cross-connect device for executing signal switching such as change of connection to a spare line when a failure occurs. Now, nodes N2 and N3 of the counterclockwise line W2
If a failure P1 occurs between the nodes, the node N3 switches the input point from L1 to L2 and receives a signal from the backup line S2 at the same time as the detection of the failure.

Since the same signal as that of the normal line W2 is transmitted to the backup line S2, the disconnection of the signal can be avoided by such connection switching. By storing such connection switching in the memory as connection information in advance, high-speed switching can be performed when a failure occurs. Less than,
Each node N1 to N1 of the ring network to which the present invention is applied
N5 will be described in detail.

FIG. 2 is a block diagram of nodes N1 to N5 shown in FIG. In FIG. 2, a switch 101 is a cross-connect device that can arbitrarily cross-connect a plurality of input points and a plurality of output points. Here, N input points R _W11 -R _W1N corresponding to the clockwise line W1, N input points R _S11 -R _S1N which are the spare lines, and M input points corresponding to the counterclockwise line W2. R _W21 -R _W2M , M which is the spare line
The book input points R _S21 -R _S2M are respectively set.

Output points T _W11 -T _W1N , T _S11 -T _S1N , T _W21 -T _W2M , and T _S21 -T _S2M corresponding to these input points are also set. Although not shown, other input points and output points are also set, and any point between these input and output can be connected. The clockwise and counterclockwise lines W1, S1, W2, and S2 respectively correspond to the fault detector 1
02 to 105 are connected to the switch 101.

Each of the fault detection units 102 to 105
1, S1, W2, and S2 are monitored for failure occurrence, and failure detection information is sent to the CPU (Central Proc.) When a failure occurs.
essingUnit) 106 is notified. For example, the fault detector 102 monitors each subline, that is, the signal input point R _W11 -R _W1N of the N clockwise line W1,
For example signal the failure of the input point R _W11 and R _W 12 is notified to the CPU106 be generated. The same applies to the other failure detection units 103 to 105.

The CPU 106 includes failure detection units 102 to 10
The type of the failure is determined in accordance with the failure detection information output from the connection information 5, and the connection switching of the switch 101 is determined by referring to the connection information stored in the connection information table 107. As will be described later in detail, the connection information table 107 stores normal connection information of the switch 101 and connection information at the time of occurrence of any failure in a table format. That is, the connection information table 107 schematically includes the connection destination table 107a and the normal connection destination table 10.
7b.

The CPU 106 has a ROM (Read Only Memory)
ry) 108 executes a program stored in advance to execute transmission control and switching control of the node. Needless to say, the CPU 106 controls the switch 101, the failure detection units 102 to 105,
Connection information table 107, ROM 108, and RAM
(Not shown) and the like.

[0015] The program stored in the ROM includes a fault specifying program for specifying the type of fault from the predefined types of faults occurring on the input line when a fault occurs on the input line; A search processing program for searching the connection information table 107 that stores connection destination information indicating the connection status of the switch 101 corresponding to the specified failure type, according to the searched connection destination information. And a switching control processing program for switching the connection state of the switch 101.

FIG. 3 shows the connection information table 107 shown in FIG.
Destination table 107a that classifies the contents of failures by the type of failure
FIG. 10 is a schematic diagram of a normal connection destination table 107b showing a correspondence relationship between input and output points in a normal state. 3, setting information such as input points that can be connected and connection types is stored in advance in the connection destination table 107a corresponding to each output point of the switch 101.

It is also allowed that one input point corresponds to (is connected to) a plurality of output points. The connection type is a parameter for classifying a connection method for realizing a complicated signal path on a network by combining a plurality of input points and output points, and is set for each output point.

In FIG. 3, the normal connection destination table 107b stores in advance information indicating a connection relationship between each input point and an output point in a normal state.
By referring to the normal connection destination table 107b, an output point corresponding to the input point in which a failure has occurred can be obtained. The fault # is a type of fault such as a single fault or multiple faults, and is defined in advance in particular according to the degree of the multiple faults. By setting one connection destination table for one failure type, the CPU 106 can determine the switching destination point from the failure type (failure #) and the failure occurrence point.

FIG. 4 shows the connection destination table 107a shown in FIG.
FIG. 9 is a schematic diagram of a table that stores information on which the normal connection destination table 107b is created upon creation. Stores connection destination information corresponding to the type of failure for each connection type. In this table, for convenience, the values are classified by numerical values called surface numbers #.

Here, the normal connection information of each connection type is plane number # 0, the connection destination information of failure # 1 of each connection type is plane number # 1, and the failure number # 2 of each connection type.
The connection destination information of each fault is defined as a plane number # 2, and similarly, the connection destination information of each fault is defined for each plane number. By collecting the connection destination information for each failure # (surface number #) in FIG. 4, the connection destination table 107 a and the normal connection destination table 107 b in FIG. 3 are created in advance and stored in the connection information table 107.

Therefore, the processor 106 can specify the connection destination table 107a only by determining the type of failure (that is, failure #),
07b, the output point corresponding to the failed input point can be specified, and the specified connection destination table 107 can be specified.
The input point of the switching destination can be determined from a and the output point.

FIG. 5 is a flowchart for explaining the operation of this embodiment. When a fault interrupt is generated from at least one of the fault detection units 102 to 105, the processor 106 calls a fault routine and determines the type of fault that has occurred (for example, the fault that occurred is the first fault or another fault already exists). Whether there are multiple failures,
A combination of multiplexed faults) is specified (step S201).

Subsequently, a fault # is specified from the type of the fault, and the connection destination table 107a is further specified from the fault # (step S202). Then, an output point corresponding to the failure occurrence input point is acquired with reference to the normal connection destination table 107b (step S203), and a spare input point R _Sj corresponding to this output point is determined by the connection destination specified by the failure #. It is read from the table 107a (step S204).

Next, the CPU 106 determines whether or not the connection destination point R _Sj is normal according to the information from the failure detection units 102 to 105 corresponding to the read connection destination point R _Sj (step S205). ). If the determination result is normal, the CPU 106 switches the switch 101 to connect the spare connection destination point R _Sj to the output point (step S206).

As described above, the CPU 106 can execute switching from the failed input point to the spare connection destination point R _Sj only by referring to the connection information table 107. Next, the CPU 106 determines whether or not the input point where the failure has occurred, for example, the input point R _Wi has been recovered (Step 207).

If the result of the determination indicates that the condition has been recovered,
The CPU 106 connects the failed input point R _Wi to the output point T _Wi and returns the switch 101 to a normal connection (step S208). On the other hand, step S
If it is determined in 205 that the connection point R _Sj is not normal, the CPU 106 compares the failure level between the input point R _Wi in which the failure has occurred and the connection point R _Sj, and determines which point to switch to. A determination is made (step S209).

Next, the connection switching operation of the switch 101 will be described with reference to FIG. Here, in order to simplify the description, a case where a single failure (referred to as failure # 1) occurs at an input point _RW11 of a clockwise line W1 in the ring network of FIG.

The connection information table 107 includes a connection information table at the time of occurrence of a failure in addition to the connection information table at the time of normality as described above. Now, as shown in FIG. 3, the output point T _W11 is connected to the input point R during normal connection.
_W11 is connected (connection L1), and when failure # 1 occurs, R
_S11 is set to be connected (connection L2).

When detecting the occurrence of the failure # 1 at the input point R _W11 , the CPU 106 specifies the output point T _W11 corresponding to the input point R _W11 from the normal connection destination table. Next, the connection destination table 107a of the plane number corresponding to the failure # 1 is determined, and a spare connection destination point R _S11 is determined with reference to the connection destination table 107a. Then, after confirming that the spare connection destination point R _S11 is normal, as shown in FIG. 6, the CPU 106 switches the switch 101 from the normal connection L1 to the spare connection L2 when a failure occurs.

Similarly, when multiple failures occur, failure #
The connection destination point can be uniquely determined with reference to the connection information table 107 in accordance with the following. Therefore,
The CPU 106 can perform connection switching simply by checking the presence or absence of multiple failures and referring to the connection information table. Even when multiple failures occur, the time required to complete connection switching is extremely short.

[0031]

As described above, according to the present invention, the connection destination information corresponding to the type of the fault is stored in the memory in advance, so that when the actual fault occurs, the switch can be referred to simply by referring to the memory. Can be uniquely determined. Thus, high-speed switching can be realized without having to calculate by a firmware program as in the related art. In particular, if connection destination information is defined in advance and stored in a memory according to the degree of multiplexing of multiple faults, high-speed switching can be achieved even when multiple faults occur.

Further, since the connection destination information corresponding to the type of the fault is stored in the memory and read only in response to the actual fault, the program does not branch as in the related art. For this reason, the flow of the switching process at the time of occurrence of a failure can be easily grasped, which is extremely effective in terms of maintenance.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a ring network according to an embodiment of the present invention.

FIG. 2 is a block diagram of a node shown in FIG. 1;

FIG. 3 is a schematic diagram of a connection destination table in which contents of the connection information table shown in FIG. 2 are classified according to types of failures.

FIG. 4 is a schematic diagram of a table storing information used as a basis for creating the connection destination table shown in FIG. 3;

FIG. 5 is a flowchart illustrating a connection switching operation of the node illustrated in FIG. 2;

FIG. 6 is a diagram illustrating a specific operation of the switch shown in FIG. 2;

[Explanation of symbols]

101: switch, 102 to 105: failure detection unit, 10
6. Processor, 107 Connection information table, 107a
... Connection destination table, 107b ... Normal connection destination table, N
1 to N5: nodes, L1: normal connection, L2: standby connection,
W1: clockwise line, W2: counterclockwise line, S1
... A spare line of W1 and a spare line of S2.

Claims (12)

[Claims] 1. A connection switching method of a switch for selectively setting a connection path between a plurality of input lines and a plurality of output lines, wherein a type of a fault occurring in the input line is defined, and The connection destination information indicating the connection state of the corresponding switch is stored, and when a failure occurs in the input line, the failure type is specified based on the defined failure type, and the failure type is identified. A connection switching method comprising: reading connection destination information to be connected; and switching the connection state of the switch based on the read connection destination information. 2. The connection switching method according to claim 1, wherein the connection destination information indicates a connection destination input line of an output line to which the failure input line is normally connected. 3. The connection switching method according to claim 1, wherein the step of defining the type of the failure includes defining the type of the failure in advance according to the multiplicity of a single failure and multiple failures. Method. 4. A connection switching method for a switch, which is provided at a node of a ring network and selectively sets connection paths between a plurality of input lines and its spare lines and a plurality of output lines and its spare lines. Defines the type of fault that occurs on the input line, stores connection destination information indicating the backup line connection of the switch according to the type of fault, and stores the type of fault defined when a fault occurs on the input line. Each step of identifying a type of a failure based on the information, reading connection destination information corresponding to the identified failure type, and switching the switch to a corresponding spare line connection based on the read connection destination information. A connection switching method characterized by the above-mentioned. 5. The connection switching method according to claim 4, wherein the connection destination information indicates a connection destination spare input line of an output line to which the failure input line is normally connected. 6. The connection switching method according to claim 4, wherein the step of defining the type of the failure includes defining the type of the failure in advance according to the multiplicity of a single failure and multiple failures. Method. 7. A connection switching device provided in each of a plurality of nodes constituting a network, wherein the node is a connection path between a plurality of input lines and a plurality of output lines interconnected in the network. A switch for selectively setting the connection line, a storage unit for storing connection destination information indicating a connection state of the switch according to a type of a failure occurring in the input line defined in advance, and a failure occurrence in the input line. A plurality of monitoring means for individually monitoring, and specifying the type of the fault detected by the monitoring means based on the defined fault type, and connecting destination information corresponding to the specified fault type from the storage means. Control means for reading and switching the connection state of the switch. 8. The connection switching device according to claim 7, wherein the connection destination information indicates a connection destination input line of an output line to which the fault occurrence input line is normally connected. 9. The connection switching device according to claim 7, wherein the storage unit stores connection destination information that specifies at least one of the input lines corresponding to each of the output lines for each type of fault. A connection switching device comprising a connection destination table. 10. The connection switching device according to claim 7, wherein the type of the failure is defined in advance according to the multiplicity of a single failure and multiple failures. 11. A storage medium storing a program for causing a processor to execute control of a switch for selectively setting a connection path between a plurality of input lines and a plurality of output lines, wherein the program includes: When a failure occurs in the input line, a failure identification processing program that identifies the type of failure from among predefined failure types that occur in the input line; and a connection state of the switch according to the failure type. A search processing program for searching connection destination information corresponding to a specified type of failure from a memory storing connection destination information indicating a connection failure, and a switching control processing program for switching a connection state of the switch according to the searched connection destination information And a storage medium storing the following. 12. The storage medium according to claim 11, wherein the type of the fault is defined in advance according to the multiplicity of a single fault and multiple faults.