JPH0828714B2 - Network switching method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication network system, and more particularly to backup technology in the event of a failure.

[0002]

2. Description of the Related Art Conventionally, when switching access to a host computer to a backup port, Japanese Patent Laid-Open No.
As described in Japanese Patent No. 261756, a method has been adopted in which the destination address for accessing the host computer is changed on the terminal side or an expensive line switching device is installed outside.

[0003]

Among the conventional methods, in the method of changing the access address to the backup host on the terminal side, it is necessary to switch the system of the host computer in all terminals that access the host computer. There is a drawback in that the time and effort required for the switching are wide, and it takes time for all terminals to access the backup system host.

Further, the method of arranging the line switching device outside has a drawback in that the cost is heavy.

The object of the present invention is to provide a service to a backup port when the host computer fails, the terminal device does not have any involvement in the address of the backup host computer, and there is no need to separately prepare a line switching device. An object of the present invention is to provide a network switching method capable of switching the network.

[0006]

SUMMARY OF THE INVENTION A network switching system according to the present invention provides a data communication network containing a host computer having ports for normal operation and backup, and a terminal device receiving service from those host computers. In the data exchange system to be configured, a network state management table for managing whether the operating state of the host computer is the operating state by the normal port or the operating state by the backup port due to the occurrence of a failure, and the normal port use Normal route definition table used to determine the call setup / data relay route by referring to the destination number during operation, and used to determine the call setup / data relay route by referring to the destination number when using the backup port Backed up Definition table, a normal subscriber management table that determines the subscriber accommodation port in the local system from the destination number during normal port operation, and a backup subscriber management that determines the subscriber accommodation port in the local system when using the backup port Table, means for rewriting the operating status of the network status management table to normal or backup according to an instruction from an external network management device or the host computer itself, route determination and joining in the normal status depending on the status of the network status management table The normal route definition table and the normal subscriber management table when deciding the subscriber port, and the route decision when the backup state is set, and the backup route definition table and the backup subscriber management when the subscriber port is decided. Te And has a means for referencing a network, and when a failure occurs in the host computer, it is possible to connect to the backup host computer by the function of the network side without changing the calling address from the terminal side. And

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a data exchange system 1 according to the present invention.
1 shows an overall configuration of 1. The system has a network state management table 12, a normal route definition table 13, a backup route definition table 14, a normal subscriber management table 15, and a backup subscriber management table 16 as management data. Further, as software processing, under the OS 110, basic exchange processing 19, network state management processing 17, route / subscriber port determination processing 1
8 works.

The network state management table 12 has two states, that is, the operating state of the host computer,
It represents either the operating state by the normal port or the operating state by the backup port due to the occurrence of a failure or the like, and these states are in accordance with the manual command input from the network management device 111. It is rewritten by the network state management processing 17. Further, this instruction may be issued from the host computer itself.

Normally, the network status management table 12
The content of indicates that the host computer is operating in the normal port. When the host computer enters the backup state, it is rewritten to display the backup port operating state by the above control.

As shown in FIG. 2A, the normal route definition table 13 and the backup route definition table 14 transmit data to the data transmission destination station and the destination station in the normal state and the backup state, respectively. The trunk line route to be used when doing so is defined.

In the normal subscriber management table 15 and the backup subscriber management table 16, as shown in FIG. 2B, the accommodating station of the subscriber and the accommodating port in the station in the normal and backup cases, respectively. Indicates the position.

The basic exchange processing 19 in the system calls the route / subscriber port determination processing 18 when determining the trunk line transmission route of the data packet and the transmission port in the own station. The route / subscriber port determination processing 18 refers to the network state management table 12 and checks whether the network state is an operating state using a normal port or an operating state using a backup port.

If the operating state is due to the use of the normal port, the normal subscriber table 15 is referred to find the accommodation station of the destination subscriber, that is, the destination station. Next, the normal route definition table 13 is referred to, and the relay port for transmitting the data to the previously obtained destination station is selected. When the destination subscriber is his / her own station, the normal subscriber management table 1 is used to determine to which port in the own station the data should be sent without selecting the trunk line route.
Calculate using 5. In this way, the basic exchange processing 19
Determines a data transmission destination relay route or a data transmission destination local station port in a situation where the host computer normally uses the port for the service, and transmits the data to that.

On the other hand, the network status management table 12
As a result of the reference, when the host computer is operating using the backup port, the normal subscriber management table 1
5 and the normal route definition table 13 are referred to, the backup subscriber management table 16 and the backup route definition table 14 are referred to, the same processing is performed, and the host computer performs the service at the backup port. Data relay destination,
Alternatively, the destination own station port is determined and the data is sent to that port.

Next, the entire network in the present invention will be described with reference to FIGS. 3 and 4. In the figure, 21 to 26 are data exchange systems, 27 is a host computer (normal system), 28 is a host computer (backup system),
Reference numeral 29 is a network management device, and 210 to 213 are terminal devices.

A request for rewriting the network status management table is input from the network management device 29 by a command of the network operator as shown in FIG. 3, and the information is known by a known technique for all data exchange systems 21 to 26 constituting the network. Will be notified. This instruction can also be issued from the host computer itself. The data exchange systems 21 to 26 rewrite the contents of the network state management table by the above-mentioned software processing according to the rewriting request. For example, it is assumed that a rewrite request to the backup port use state is made while the host computer is using the normal port to perform the service. In that case, as shown in FIG. 4, the conventional terminal 210 accessing the host computer 27 which normally performs the service has a table to refer to when determining the relay route and the subscriber port as described above. The terminal 210 to 213 calls the backup computer 28 accommodated in the backup port even if the terminals 210 to 213 call the host computer with the same address because the backup port is used.

[0018]

As described above, according to the network switching system of the present invention, when the host computer has a failure, the terminal device does not have any relation to the address of the backup host computer, and the line switching device is specially prepared separately. It is possible to complete the switching of the service to the backup port without needing to do so.

[Brief description of drawings]

FIG. 1 is a diagram showing a data exchange system in the present invention.

FIG. 2 is a diagram showing a route definition table and a subscriber management table.

FIG. 3 is a diagram for explaining a backup switching request.

FIG. 4 is a diagram for explaining communication with a backup port.

[Explanation of symbols]

 11 Data Exchange System in the Present Invention 12 Network State Management Table 13 Normal Route Definition Table 14 Backup Route Definition Table 15 Normal Subscriber Management Table 16 Backup Subscriber Management Table 17 Network State Management Process 18 Route / Subscriber Port Determination Process 19 Basic Exchange Processing 110 OS 111 Network management device 21-26 Data exchange system 27 Host computer (normal system) 28 Host computer (backup system) 29 Network management device 210-213 Terminal device

Claims (2)

[Claims] 1. A data exchange system comprising a data communication network containing a host computer having ports for normal operation and backup and terminal devices receiving services from these host computers. A network status management table that manages whether the status is the operation status by the normal port or the operation status by the backup port due to the occurrence of a failure, and the call setting / data by referring to the destination number when the normal port is used. Normal route definition table used to determine the relay route, backup route definition table used to determine the call setup / data relay route by referring to the destination number when using the backup port, and normal port operation Sometimes the destination number Ordinary subscriber management table that determines the subscriber accommodation port in the local system, a backup subscriber management table that determines the subscriber accommodation port in the local system when using the backup port, and an external network management device or the host computer itself Means for rewriting the operating state of the network state management table to normal or backup according to an instruction from the above, and when determining the route in the normal state according to the state of the network state management table, and when determining the subscriber port, the normal route definition table And a means for referencing the backup route definition table and the backup subscriber management table when deciding a route in the case of a backup state and deciding a subscriber port in the case of a backup state, and a host computer. When a failure occurs, making it possible to connect to the backup host computer at the network side of the functions without changing the call address from the terminal side, the network switching method. 2. The normal route definition table and the backup route definition table include a data transmission destination station and a trunk line route used when data is transmitted to the destination station in each of the normal time and the backup time. It is defined that the accommodation station of the subscriber and the accommodation port position in the station are defined in the normal subscriber management table and the backup subscriber management table in the normal and backup cases, respectively. Claim 1
Network switching method described.