JP2822936B2 - Path detour system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a path detour system, and more particularly to a path detour system for setting a path by bypassing a failure point when a failure occurs on a network.

[0002]

2. Description of the Related Art Conventionally, a network system is composed of a plurality of nodes and a line connecting the nodes, and communication between nodes is performed by setting a path on the line. .

When a fault occurs in a line in the above network system, a node connected to the line searches for a detour path other than the line in path units, and is connected using the searched detour path before the fault occurs. Communication with the failed node has been restored.

[0004]

In the above-described conventional path detour system, when a failure occurs in a line of the network system, the detour path is searched for in units of paths, so that a large number of exchanges of search control commands occur. Along with
It takes time to search for a detour route.

Therefore, an object of the present invention is to solve the above-mentioned problems, to reduce the exchange of commands when searching for a detour path, and to provide a path detour system capable of shortening the detour path search time. To provide.

[0006]

SUMMARY OF THE INVENTION A path bypass system according to the present invention is a network path bypass system comprising a plurality of nodes and a line connecting the nodes, wherein a communication of a path set to the line is performed. Storage means for storing the capacity, priority information of the path, and connection information of the path; and a setting for the line based on the communication capacity of the path stored in the storage means when a failure occurs in the line. Calculating means for calculating a total communication capacity of a plurality of paths; detour searching means for performing a detour search processing using the total communication capacity calculated by the calculating means as a required band value; and searching by the detour searching means Selecting means for selecting a detour path according to the priority information of the path stored in the storage means when the total communication capacity of the detour is smaller than the required bandwidth value; Means for switching all paths to the detour when the total communication capacity secures the required bandwidth value, and switching the detour path to the detour when the total communication capacity of the detour is less than the required bandwidth value and,
The detour search for any one of the plurality of nodes;
When a detour search command is input from the search means,
To determine whether the required bandwidth value can be secured on the line with
Determining means, and the required band value can be secured by the determining means.
If it is determined that the node is not
Add the route information indicating that the route has been passed to the next adjacent node
Means for transmitting the required band value to the
When it is determined that the detour search is impossible,
Rewrite the required bandwidth value to the maximum bandwidth value that can be secured and
Means for adding reason information and sending the information to the next adjacent node is provided for each of the plurality of nodes.

[0007]

Another path detour system according to the present invention, in addition to the above-mentioned configuration, further comprises a judging means for judging whether or not the other end of the line in which the fault has occurred, and one of the plurality of nodes. Determining means for determining whether or not the required band value can be secured on a line with the node when a detour search command is input from the detour searching means, and the other end of the line on which the failure has occurred in the determining means Means for sending a response command to the bypass search command to one end of the line in which the failure has occurred based on the route information when it is determined that the required bandwidth value can be secured by the determination means; and Means for determining a response command to the detour search command when it is determined that the other end of the line in which the failure has occurred is determined by the means, and when the determination means determines that the required bandwidth value cannot be secured. And means for sending to one end of the line where the fault has occurred based on the way information is rewritten to the maximum bandwidth value that can ensure the main band value is provided to said plurality of nodes each.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the operation of the present invention will be described below.

[0010] The search for a detour by the node that has detected the failure is performed not in units of paths but in units of the total communication capacity of the paths set in the line in which the failure is detected. by this,
The exchange of commands when searching for a detour route is reduced, and the search time for a detour route can be shortened.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. In FIG. 1, a node 1 includes a CPU (Central Processing Unit) 11, a switch 12, a line failure detection unit 13, and a memory 14, and the switch 1
2, a plurality of lines 21 to 2n are connected. Here, paths 111,..., 12
1,..., 1n1, 1n2 are set.

The CPU 11 controls the switch 12 to connect the paths 111,..., 121,. The line failure detection unit 13 performs a failure detection process for each of the lines 21 to 2n, and notifies the CPU 11 when a failure is detected.

.., 12 are stored in the memory 14.
Each communication capacity, each priority, and each connection information are stored in advance. CP
When U11 is notified of the failure detection from the line failure detection unit 13, U11 executes a detour search process based on the contents of the memory 14,
If the total communication capacity (required bandwidth value) of the plurality of paths set in the failed line in the searched detour is secured, all of the plurality of paths set in the failed line are set as the detour. Switch.

If the CPU 11 does not secure the total communication capacity of the plurality of paths set in the line in which the fault has occurred in the searched detour, the CPU 11 switches the path having the higher priority based on the contents of the memory 14 to the detour path. And only the detour path is switched to the detour.

FIG. 2 is a diagram showing a system configuration according to one embodiment of the present invention. In the figure, a network system according to an embodiment of the present invention includes a plurality of nodes 1a to 1f and lines AB, BC, BD, and B connecting the nodes 1a to 1f.
E, CE, and EF.

Lines AB, BC, BD, BE, CE, EF
Pass 101-106 connecting remote locations via lines
Is set. Each of the nodes 1a to 1f has the same configuration as the configuration of the node 1 shown in FIG.

Now, assuming that a fault has occurred in the line BE,
The CPU 11 of the node 1b which is one end of the line BE issues a detour search command Q1 to the adjacent nodes 1a, 1c and 1d based on the contents of the memory 14, respectively.

Since the nodes 1a and 1d have no adjacent node other than the node 1b, the detour search command Q1 is discarded. However, since the node 1c has an adjacent node 1e other than the node 1b, it has passed through its own node. Is issued to the node 1e. The detour search command Q2 is added to the detour search command Q1.

In this case, if the communication capacity that can be secured on the line BC between the node 1c and the node 1b is smaller than the total communication capacity of the paths 102, 103, and 105 set on the line BE, the detour search command Q1 The detour search command Q2 in which the required bandwidth value is rewritten with the communication capacity that can be secured in the line BC and the route information is added is transmitted to the node 1e.
Issue to

Since the node 1e is the other end of the line BE in which the fault has occurred, the node 1c sends a detour search command Q2
Is received, a response command R is sent to the node 1b in accordance with the route information of the bypass search command Q2.

The nodes 1b are connected to the paths 102, 103, and 10 set on the line BE in which a fault has occurred in the searched detour.
If the total communication capacity of 5 is secured, the paths 102, 10
Switch all 3,105 to the detour.

If the total communication capacity of the paths 102, 103, and 105 is not ensured in the searched detour, the node 1b selects a path of the communication capacity secured based on the contents of the memory 14 with a higher priority. The detour paths are sequentially selected, and only the detour path is switched to the detour path.

FIG. 3 is a flowchart showing the processing of the failure detecting node according to one embodiment of the present invention, and FIG. 4 is a flowchart showing the processing of the detour search command input node according to one embodiment of the present invention.

Referring to FIGS. 1 to 4, the processing at the node where the failure is detected and the processing at the node to which the detour search command is input according to the embodiment of the present invention will be described. Hereinafter, description will be made on the assumption that a failure has occurred in the line BE as shown in FIG.

A fault occurs in the line BE, and this
When the line failure detection unit 13b detects the failure, the line failure detection unit 13 notifies the CPU 11 of the occurrence of the failure in the line BE. The CPU 11 of the node 1b detects the location of the failure based on the failure notification from the line failure detector 13 (step S1 in FIG. 3).

The CPU 11 of the node 1b sends a signal from the memory 14 based on the detected information to the
Then, the communication capacity of each of the paths 102, 103, and 105 set is read, and the total communication capacity of the paths 102, 103, and 105 is calculated (step S2 in FIG. 3).

The CPU 11 of the node 1b generates a detour search command Q1 using the total communication capacity as a required bandwidth parameter (step S3 in FIG. 3), and sends the detour search command Q1 to the adjacent nodes 1a, 1c, 1d. Transmit (step S4 in FIG. 3).

Upon receiving the detour search command Q1 from the node 1b, the nodes 1a and 1d adjacent to the node 1b determine whether there is a further adjacent node (step S11 in FIG. 4). Since the nodes 1a and 1d determine that there is no adjacent node, the detour search command Q1 from the node 1b is discarded (step S12 in FIG. 4).

On the other hand, since the node 1c determines that there is an adjacent node, it determines whether or not it is the other end of the line BE in which the failure has occurred (step S13 in FIG. 4). In this case, the node 1c determines that it is not the other end of the line BE in which the failure has occurred.
It is determined whether a bandwidth equal to or greater than the required bandwidth value, which is a parameter of the detour search command Q1, can be secured (step S14 in FIG. 4).

If the node 1c determines that a band equal to or greater than the required band value can be secured, the node 1c adds the route information indicating that the node 1c has been passed to the bypass route search command Q1 to generate a bypass route search command Q2. Road search command Q
2 to the next adjacent node 1e (step S1 in FIG. 4).
5).

On the other hand, if the node 1c determines that a band exceeding the required band value cannot be secured, the detour search command Q1
Is rewritten to the maximum bandwidth value that can secure the required bandwidth value, and further, the route information indicating that the route has passed through the node 1c is added to generate the bypass route search command Q2. The message is transmitted to the node 1e (step S16 in FIG. 4).

Upon receiving the detour search command Q2 from the node 1c, the node 1e determines whether or not there is a further adjacent node (step S11 in FIG. 4). Node 1
In e, since it is determined that there is an adjacent node, it is determined whether or not it is the other end of the line BE in which a failure has occurred (step S13 in FIG. 4).

In this case, since the node 1e determines that it is the other end of the line BE in which the failure has occurred, it checks the band that can be secured with the node 1c, and checks the required band value which is a parameter of the detour search command Q2. It is determined whether or not the bandwidth can be secured (step S17 in FIG. 4).

When the node 1e determines that a bandwidth equal to or greater than the required bandwidth value can be secured, the search response command R uses the required bandwidth value of the detour search command Q2 as a secured bandwidth value parameter.
Is generated, and the search response command R is returned to the node 1b that has started the search by following the route information of the detour search command Q2 (step S18 in FIG. 4).

If the node 1e determines that a bandwidth equal to or greater than the required bandwidth value cannot be secured, the node 1e generates a search response command R using the maximum bandwidth value that can be secured as a secured bandwidth value parameter. Q2
(Step S19 in FIG. 4).

When the node 1b receives the search response command R from the node 1e, which is the other end of the line BE in which the fault has occurred (step S5 in FIG. 3), the node 1b checks the reserved band value parameter of the search response command R to determine the required band value. (Path 102,
It is determined whether or not the total communication capacity (103, 105) is secured (step S6 in FIG. 3).

If the required bandwidth value is secured, the node 1b performs path switching processing for all of the paths 102, 103, and 105 (step S8 in FIG. 3). The path switching process of the path is performed from the node 1b to the nodes 1c and 1e.
Path ID assigned to each of 02, 103 and 105
This is performed by instructing path connection switching using (identification information) as a key.

On the other hand, if the required bandwidth value is not secured, the node 1b selects a detour path for the secured bandwidth based on the priority of each of the paths 102, 103 and 105 stored in the memory 14. (Step S7 in FIG. 3), pass 1
A path switching process is performed on the detour path selected from 02, 103, and 105 (step S8 in FIG. 3). The path switching process of the path is performed from the node 1b to the nodes 1c and 1e.
Then, by using the path ID (identification information) assigned to each of the detour paths selected among the paths 102, 103, and 105 as a key, the connection of the paths is instructed to be switched.

In the nodes 1b, 1c, and 1e, the CPU 1
1, the path connection is changed in the switch 12 based on the path connection switching instruction, and the path detour processing is completed.

FIG. 5 is a diagram showing the system configuration of the network after the completion of the path detour processing according to one embodiment of the present invention. FIG. 5 shows a state in which only the paths 102 and 105 among the paths 102, 103 and 105 set in the line BE in which a failure has occurred are bypassed.

In this case, the path 102 goes from node 1a → line AB → node 1b → line BC → node 1c → line CE →
The route becomes node 1e → line EF → node 1f,
Path 105 is node 1d → line BD → node 1b → line BC → node 1c → line CE → node 1e → line EF →
The route is a node 1f.

FIG. 6 is a diagram showing a system configuration in a case where there are a plurality of detour paths in the path detour processing according to one embodiment of the present invention. FIG. 7 is a diagram showing a path detour processing using a plurality of detour paths of FIG. It is a figure showing the system configuration of the network after completion.

When a failure occurs in the line BE in the network configuration shown in FIG. 6, the search for the detour by the node 1b is performed in the same manner as the above-described detour search processing. In this case, the detour search command Q Is transmitted from the node 1b to the node 1c through the line BC,
It is also transmitted directly to the node 1e via the line BE1. Therefore, the node 1b detects the route of the line BE1 → node 1e in addition to the route of the line BC → node 1c → line CE → node 1e.

When a plurality of detours are detected at the node 1b, the number of hops of the detour, the band of the detour, the path 101,
It is determined which path is to be assigned to which detour in consideration of the required bandwidth of 102 and the priority of the path.

In FIG. 7, of the paths 101 and 102 set in the line BE in which the fault has occurred, the node 101 is assigned to the path 101.
c, that is, a route of node 1a → line AB → node 1b → line BC → node 1c → line CE → node 1e, and a line BE1 → node 1 is assigned to the path 102.
The route e is assigned.

As described above, the search for the detour by the node 1b that has detected the failure is not performed on a path-by-path basis, but on the paths 102, 103, and 10 that are set on the line BE where the failure is detected.
By performing the operation in units of the total communication capacity of 5, it is possible to reduce the number of commands exchanged when searching for a bypass route, and to reduce the search time for the bypass route.

[0047]

As described above, according to the present invention, the search for a detour by a node that has detected a fault is performed not in units of paths but in units of the total communication capacity of the paths set in the line where the fault is detected. By doing so, it is possible to reduce the number of exchanges of commands when searching for a detour route, and it is possible to reduce the time required for searching for a detour route.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a system configuration according to an embodiment of the present invention.

FIG. 3 is a flowchart showing processing of a failure detection node according to one embodiment of the present invention.

FIG. 4 is a flowchart illustrating a process of a detour search command input node according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a system configuration of a network after a path detour process is completed according to an embodiment of the present invention.

FIG. 6 is a diagram showing a system configuration in a case where there are a plurality of detour paths in a path detour processing according to an embodiment of the present invention.

FIG. 7 is a diagram illustrating a system configuration of a network after a path detour process using a plurality of detour paths in FIG. 6 is completed.

[Explanation of symbols]

1, 1a to 1f Node 11 CPU 12 Switch 13 Line fault detection unit 14 Memory 21 to 2n, AB, BC, BE, BE1, CE, EF
Line 101-106, 111, 121, 1n1, 1n2 path

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04L 29/14 H04L 12/24

Claims (2)

(57) [Claims] 1. A path bypass system for a network comprising a plurality of nodes and a line connecting the nodes, wherein the communication capacity of a path set to the line, priority information of the path, and connection of the path Storage means for storing information; and calculating means for calculating a total communication capacity of a plurality of paths set for the line based on a communication capacity of the path stored in the storage means when a failure occurs in the line. A detour search means for performing a detour search process using the total communication capacity calculated by the calculation means as a required band value; and a total communication capacity of the detour searched by the detour search means being equal to the required bandwidth. Selecting means for selecting a detour path according to the priority information of the path stored in the storage means when the value is less than the value, and when the total communication capacity of the detour secures the required bandwidth value Means for switching all paths to the detour and switching the detour path to the detour when the total communication capacity of the detour is less than the required bandwidth value ;
The detour search for any one of the plurality of nodes;
When a detour search command is input from the search means,
To determine whether the required bandwidth value can be secured on the line with
Determining means, and the required band value can be secured by the determining means.
If it is determined that the node is not
Add the route information indicating that the route has been passed to the next adjacent node
Means for transmitting the required band value to the
When it is determined that the detour search is impossible,
Rewrite the required bandwidth value to the maximum bandwidth value that can be secured and
Means for adding the reason information and sending the information to the next adjacent node in each of the plurality of nodes. And determining whether the other end of the line in which the failure has occurred.
Determining means for determining, and any one of the plurality of nodes
The detour search command is input from one of the detour search means.
The required bandwidth value is confirmed on the line to the node when
Determining means for determining whether the data can be maintained;
The other end of the line in which the fault has occurred
When it is determined that the required band value can be secured by the
Response command to the search command
Means for sending the signal to one end of the line in which the failure has occurred based on
The other end of the line in which the fault has occurred
And the required bandwidth cannot be secured by the determination means.
Response to the bypass search command
Rewrite the required bandwidth value of the command to the maximum bandwidth value that can be secured
The time when the failure occurred based on the route information
2. The path detour system according to claim 1, further comprising means for transmitting a signal to one end of a line, said means being provided at each of said plurality of nodes.