JPH1013533A - Method and device for managing bypass route of communication network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manage the assignment of a backup line totally without being limited in an existing network by allowing a server to grasp a current state of a route, updating a routing table for each node and storing the result so as to inform the information to each node. SOLUTION: A server 06 grasps a current state of routes totally and updates and stores a routing table for each of nodes 01, 02 and informs the information to each of the nodes 01, 02. That is, the server 06 selects a backup route optimum to the node 01 based on the routing table when an instruction of the backup route is requested from, e.g. the node 01. The node 01 tries the connection to the instructed route and when successful, it is informed to the server 06. When successful, the server 06 updates the routing table to instruct the updated result to the nodes 01, 02. The nodes 01, 02 receiving the update instruction update its own routing table according to the instruction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for managing a detour route of a communication network, and more particularly to a method and an apparatus for managing a detour route of a communication network which collectively manage media and topology of a backup line.

[0002]

2. Description of the Related Art Conventionally, this type of bypass route management method for a communication network secures a bypass route in the same medium by acquiring route information by each node and changing a routing table for each node. Was. An example of a conventional detour route management method is described in Japanese Patent Application Laid-Open No. 2-1154. The detour route selection processing method described in this publication is a system that notifies network management center of network failure information and provides route information to each node based on the notification.

An existing network is used for a route for notifying fault information to a network management center, and a detour route also uses an existing network.

[0004]

According to the above-described conventional detour route management method for a communication network, when a node in which communication has failed selects a backup line, the media of the backup line and the destination are set to the existing network. Within. Therefore, the selection of the backup line is limited to the existing network, and there is a drawback that a network topology using another medium cannot be added.

[0005] The route list table of the network management center is a table prepared in advance, and it is difficult to add a backup route during operation. However, there is a disadvantage that it is difficult to enlarge the image.

An object of the present invention is to provide a method and apparatus for managing a bypass route of a communication network that can comprehensively manage the assignment of a backup line so as not to be limited to an existing network.

[0007]

A detour route management method for a communication network according to the present invention is a detour route management method for a communication network having a backup line. The switching center and a connection number of a node to be routed from the designated route are collectively and instructed by a general control center which performs network management of all networks.

[0008] Further, the designation of the switching destination route includes selection in consideration of predetermined conditions including a communication type and a charge. Based on the designation of the switching destination route, the connection is executed even if the node side executes a connection operation. If it is not possible, a request for designation of another medium is requested, and the central control center designates another connectable route and a connection number of a transit node again in response to the request, and the switching destination route for each node Is specified based on the routing table edited for each node stored in the central control center, and when the route switching is executed, the change of the routing table for each node is comprehensively processed by the central control center. The change result is notified to the relevant node, and the notified node receives the routing table of its own node, In addition, the integration center restores and updates the routing table by a circuit failure restoration notification, notifies the relevant node of the update result, and the node that has received the notification receives the routing table of its own node. Is also included in the communication network detour route management method of the present invention.

A detour route management device for a communication network having a backup line for each node according to the present invention provides a switchable route in response to a request from a node to specify a switching destination route due to a line failure, and a switchable route and a designated route. The central control center has means for comprehensively controlling and instructing the connection number of the node to be passed.

[0010] Further, there is provided means for selecting the designation of the switching destination route in consideration of predetermined conditions including a communication type and a charge, and based on the designation of the switching destination route,
If the node performs the connection operation but the connection is not possible, a means for requesting designation of another medium, the control center responds to the request, and specifies another connectable route and the connection number of the transit node. Have the means to specify again,
The supervising center includes means for specifying a switching destination route for the node based on the routing table edited for each node stored in the supervising center, and a routing table of the node when the route switching specified by the node is successful. Means for changing and updating the content of
Means for notifying the relevant node of the change result, each node having, upon receiving the change notification, means for updating the routing table of its own node according to the received contents, and It is also included in the detour route management device of the communication network of the present invention that has means for restoring and updating the routing table in response to a line failure restoration notification from the node.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a relevant portion of a network in which a communication network detour route management method of the present invention is adopted.

The network 01 is a specific network constituted by a dedicated line, and includes a node 01 and a node 02.
Is one of the nodes constituting the specific network. The networks 11 and 12 are networks that are assigned in advance as backup networks for the line 20. Net 15
Is a network to which each node is connected to the server 06 which manages the route in an integrated manner. The media 22, the media 21, and the media 23 represent the types of each network. The server 06 is a route management server having information such as a network topology and a line capacity in the network, and managing a routing table of each node.

A detour route management method for a communication network according to the present invention will be described with reference to the flowcharts shown in FIGS. Now, when the node 01 detects a line failure of the line 20 shown in FIG. 1 (step 61), communication with the network 10 becomes impossible, and the node 01
3 and notifies the server 06 via the network 15 that the line 20 is in failure and the media of the available backup line (step 62), and inquires about the optimum route (step 63). The server 06 receives this inquiry (step 81). From the available media of the node 01, the media 21 suitable for the backup line and the via connection destination node 02 in consideration of the communication conditions such as the network topology, the charge, and the communication type. And notifies the node 01 of the connection number (step 82). In this case, it is assumed that a detour route is assigned. If there is no detour route, it is checked whether or not there is a detour candidate at certain intervals until a new detour route is set (step 66).

The node 01 tries to connect to the network 10 according to the information in step 82 (step 64). When securing of the backup route via the selected medium 21 is completed, the node 01 notifies the server 06 of the completion (step 65). Upon receiving the notification, the server 01 changes and updates the routing table of the required node in the network 01, and notifies the relevant nodes of the change (step 84). The node that has received the change update notification (step 71) updates its own routing table (step 72). Next, the server 01 communicates with the node 01 using the network 01 and confirms that a backup line has been secured.

If the connection of the backup line specified by the server 01 fails, step 64), the node 01
Asks the server about the media of the other backup line and the connection number of the destination node as much as possible, and tries to connect sequentially (steps 62 to 64, 82, 83).

To perform the above method, each node:
When a failure is detected, the server 06 is called to notify the failure and the assigned backup route, a failure detection notification unit 1, its own routing table 2, and a routing table based on the server's instruction. And a route switching operation unit 4 for notifying the server of success if the connection operation of the backup route instructed by the server is executed and success if the operation is unsuccessful.

The server 06 changes the routing table shown in FIG. 6, receives a failure notification from all nodes, a routing table storage unit 25 storing routing tables of all nodes, and changes the routing table. A routing table updating unit 26, a route selecting unit 27 for selecting an appropriate route from the backup routes notified by the node, a route instructing unit 28 for instructing the node on the selected backup route,
It has a routing table update instructing unit 29 for notifying the related node of the updated routing table.

[0018]

The present invention will be described in detail with reference to a second embodiment. FIG. 4 shows that a specific network in which five nodes are connected by a dedicated line includes a node 31 and a node 3.
This is an example in which an ISDN network 52 and a frame relay network (hereinafter abbreviated as FR network) 51 are prepared for backup between the two. The telephone network 53 is used for communication between each node and the server 36.

When a failure occurs in the line 42, the node 31
Is connected to the server 36 through the telephone network 53, and the link 4
2 is in a failure state and that the ISDN network and the FR network are assigned to be used as backup lines. The server 31 selects the connection to the node 32 via the ISDN network 52 for the backup line from the network topology information and the information of the link 42 set in advance, and notifies the node 31 of the destination connection number corresponding to the node 32. . Based on this information, node 31
Using the SDN network 52, a connection signal is transmitted to the node 32 to attempt connection to the node 32. Node 31 is node 32
If the connection to is successful, the server 36 is notified of the success. The server 36 updates the routing table for the managed node 31 as shown in Table 1 and the routing table for the node 32 as shown in Table 2, and notifies the nodes 31 and 32 respectively. The nodes 31 and 32 update their own routing tables based on this notification.

[0020]

[Table 1]

[0021]

[Table 2] If the node 31 fails to connect the backup line to the ISDN network, it notifies the server 36 via the telephone network 53.
Notify. The server 36 determines whether connection by the FR network 51 is possible as a second backup line candidate,
This is notified to the node 31. If the connection by the FR network 51 is possible, the node 31 is notified. If connection by the FR network is possible, the node 31 tries to secure a backup line again using the FR network 51.

After switching to the backup line, the link 42
Is recovered, the node 31 reports to the recovery server 36. The server 36 updates the routing tables of the nodes 31 and 32 in the server 36 and notifies the respective servers. The servers 31 and 32 recover and update the respective routing tables based on the notification, and switch the ISDN.
It waits for the end of the call currently using the network 52 or the line of the frame relay network 51 and disconnects it.

[0023]

As described above, according to the present invention, the server which comprehensively manages various media and networks grasps the current state of the route, updates and holds the routing table for each node, and stores it in each node. Since this information is notified to each node, when there is a plurality of connectable media in each node, there is an effect that the bypass route can be used as a backup route using all the connectable media.
This has the effect of reducing the load on the routing table update and restoration update at each node.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main part of a first embodiment of a detour route management method for a communication network according to the present invention.

FIG. 2 is a flowchart of a detour route inquiry operation at the time of a line failure of a node 01 according to the first embodiment shown in FIG.

FIG. 3 is a flowchart of an operation of the server 06 of the first embodiment shown in FIG. 1 for inquiring about a detour route at the time of a line failure in a node 1;

FIG. 4 is an explanatory diagram of a main part of a second embodiment of the detour route management method for a communication network according to the present invention.

FIG. 5 is a block diagram of an embodiment of a node side device of the detour route management device of the communication network according to the present invention.

FIG. 6 is a block diagram of an embodiment of a server-side device corresponding to the node-side device shown in FIG.

[Explanation of symbols]

 1 failure detection notification unit 2 routing table 3 routing table update unit 4 route switching operation unit 01 node 02 node 06 server 10 network 11 network 12 network 15 network 20 line 21 media 22 media 23 media 24 failure notification receiving unit 25 routing table storage unit 26 routing table update unit 27 route selection unit 28 route instruction unit 29 routing table update instruction unit 31 node 32 node 33 node 34 node 35 node 36 server 42 link 43 link 44 link 45 link 46 link 47 link 51 frame relay network 52 ISDN network 53 telephone network

Claims (10)

[Claims] 1. A method for managing a detour route of a communication network having a backup line, comprising: in response to a request from each node to specify a switch destination route due to a line failure, a switchable route and a node to be routed from the specified route. A detour route management method for a communication network, wherein an instruction of a connection number is comprehensively and instructed by a general control center that performs network management of all networks. 2. The method according to claim 2, wherein the designation of the switching destination route is a communication type,
Claim 1 based on a selection considering predetermined conditions including a fee.
The detour route management method of the communication network described in the above. 3. When the node side executes a connection operation but connection is not possible based on the designation of the switching destination route, the node requests a designation of another medium, and the central control center responds to the request and performs another connection. 2. The method according to claim 1, wherein a possible backup route and a connection number to a transit node are specified again. 4. The node-specific routing table is designated based on a routing table edited for each node stored in the central control center, and when the route is switched, the node-specific routing table is specified. 2. The communication network according to claim 1, wherein the change is comprehensively processed by the central control center, the change result is notified to an associated node, and the notified node updates its own routing table based on the received notification. Detour route management method. 5. The integration center recovers and updates the routing table by a circuit failure recovery notification, notifies the relevant node of the update result, and the node that has received the notification updates its own node's routing table based on the reception result. The method according to claim 4, wherein the route is updated. 6. A backup line is provided for each node,
In the detour route management device of the communication network provided correspondingly to each node and the general center that manages all the networks, it is possible to switch in response to a request from each node to specify a switching destination route due to a line failure. A detour route management device for a communication network, characterized in that the decentralization center comprehensively designates a route and a connection number of a node to be routed from the designated route. 7. The communication destination is designated by a communication type,
7. The detour route management device for a communication network according to claim 6, further comprising means for selecting based on a predetermined condition including a fee. 8. When the node performs a connection operation but connection is not possible based on the designation of the switching destination route from the central control center, the node side requests means for specifying another route, and 7. The detour route management device for a communication network according to claim 6, further comprising: means for re-designating another connectable route and a connection number of the transit node in response to the request. 9. A control center for specifying a switch destination route for a node based on a routing table edited for each node stored in the control center, wherein when the route specified by the node is successfully switched, Means for changing and updating the corresponding contents of the routing table of the node, and means for notifying the relevant node of the change result. Each node, upon receiving the change notification, stores the routing table of its own node. 7. The detour route management device for a communication network according to claim 6, further comprising: means for updating the communication route. 10. The detour route management device for a communication network according to claim 9, wherein the supervisory center has means for restoring and updating the routing table in response to a line failure restoration notification from an arbitrary node.