JPH06332810A - Communication method for network system provided with duplex system equipment - Google Patents

Abstract

PURPOSE:To perform data communication to a main system side equipment inside duplex system equipments from the other equipment without recognizing which equipments constituting the duplex system equipments is a main system by not only determining port numbers for the respective equipments beforehand but also determining representative port numbers for the duplex system equipments themselves. CONSTITUTION:The duplex system equipments 302 and 303 are provided with the equipments 307 and 308 and the equipments 309 and 310 respectively capable of optionally switching the main system and a subordinate system. Loops 304 and 305 which are respective networks are connected through a connector 306 such as a router or the like. Then, for communication addresses, the port numbers allocated to the respective equipments 307-310 beforehand are used and in the duplex system equipments 302 and 303, further logical representative port numbers are allocated beforehand and used as the communication addresses. Thus, since a transmitter confirms a state to the duplex system equipments by itself and then performs transmission, the transmission can be performed to the target main system equipment without the transmitter for relay.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication technique for transmitting data in a network system including a dual system device.

[0002]

2. Description of the Related Art In recent years, technology for decentralizing computer systems has been developed due to higher performance and lower cost of information processing systems such as computers and further development of network technology.

As an example of a conventional data communication method in a network, for example, a communication method using a communication frame called "MAC frame", which is defined by IEEE802.3, is well known.

The "MAC frame" comprises a head port number part composed of a source port number, a broadcast address at the time of broadcast transmission, and a destination port address at the time of point-to-point communication, and a data part. is doing.

In such a communication method, the communication frame configured as described above is used as a communication protocol for transmission.

Now, as a method of transmitting data to the main system side of a multiplex system device (which is usually constituted by including a main system device and a slave system device), for example, as shown in FIG.
A transmission control device 405 is provided between the duplex system device 402 and the network 408, and the transmission control device is
There is a method of determining which device in the dual system device is the main system and performing a relay process for transmitting data.

Further, in a network device having a structure in which a transmission side device which is a data transmission side and a multiplexing system device which is a data reception side are connected via a common bus line, they are connected to the bus line in advance. In the shared memory provided, information about which of the multiplex system devices is the master side is stored in the shared memory, and the transmitting side device refers to the master-slave information in the shared memory during data transmission. Then, a method of performing communication is known.

Further, a method is known in which, when a switching of operating systems occurs in the multiplex system device, the communication partner device is notified of the information indicating that the system switching has occurred.

[0009]

According to the conventional communication method, in the network configuration as shown in FIG. 3, the main system side of the dual system device 302 including the device 301 to the device 307 and the device 308. Consider transmitting various types of data to the device.

In this case, data will be transmitted by the following procedure.

First, the device 301 asks the device 307 and the device 308 which compose the duplex system device 302 which one is the main system device, which is information such as "transmission request". To send.

The device 30 which has received the "transmission request"
7 or the device 308 transmits information to the device 301 that the device itself is the main device.

As a result, the device 301 recognizes the main system device and transmits data to the main system device. Therefore, in the data transmission between the device 301 and the main system device that constitutes the dual system device, it is necessary to perform communication processing at least three times (data transmission to the main system will be performed at the third time). there were.

If such an exchange is carried out every time data is transmitted, problems such as an increase in network load and an increase in processing time for data transmission occur.

In order to solve such problems, the following means have been proposed.

First of all, between the device 403 and the device 404 constituting the dual system device as shown in FIG.
5 is a means for deciding the master-slave information in the duplex system device by adopting a configuration in which a transmission control device is provided.

However, in such a configuration, a transmission control device must be provided in response to an increase in the number of multiplex system devices, resulting in an increase in cost. Further, when the communication function of the transmission control device is stopped due to a failure or the like, there is a problem that data transmission cannot be performed even if the multiplex system device is operating.

Secondly, a transmitting side device for transmitting data,
If a dual system device is connected through a common transmission line and a shared memory is further provided and the mutual data transmission is managed based on the information stored in the shared memory, It is necessary to manage all of them, and for example, there is a problem that a problem such as a long transmission line occurs and construction of a wide area system having a plurality of networks becomes unrealistic.

Thirdly, in the method of notifying a communication partner of a state change (such as switching between the master system and the slave system) from the multiplex system device, all the communication partners are known in advance. However, there is a problem in that when a system as a communication partner is out of order and a notification leak occurs, a device that has failed the notification cannot perform data transmission to the main system side.

Therefore, in the present invention, in view of the above problems, even if it is not recognized which of the devices constituting the dual system device is the main system, the dual system device can be operated by other devices. It is an object of the present invention to provide a communication method capable of performing data communication with a main system side device therein.

[0021]

[Means for Solving the Problems] In order to solve the above problems, the following means can be considered.

A data transmission method between devices in a network system in which a plurality of devices, at least one of which is a dual system device, are connected via a communication means, wherein a port number is predetermined for the device. Further, when the device is a dual system device, in addition to predefining port numbers for the two devices that compose the device, a representative port number is also predetermined for the dual system device itself. Aside,
Each of the above-mentioned devices stores status information indicating whether each of the two devices constituting each dual-system device connected to the network system is a master system or a slave system. When the port number is used as a data communication address, the representative port number is converted into the port number of the main system device based on the status information, and the data is transmitted. Is.

Further, in this case, the above-mentioned status information is queried by each of the above-mentioned devices at the time of system start-up to the two devices constituting each dual-system device connected to the network system. It is preferable to check and remember.

It is preferable to update the status information at a predetermined time (for example, periodically, at the time of failure, etc.).

[0025]

According to the communication method of the present invention, a device forming a multiplex system can be handled as a single virtual device without considering whether it is a master system or a slave system.

That is, the actual data transmission is performed after confirming the port number of the device of the data transmission destination, that is, after obtaining the port number of the corresponding device in the duplex device which is the communication destination. , It is not necessary to recognize the configuration of each device in the multiplex system device.

Of course, by using the port number given to each of the plurality of devices as the communication address of the device corresponding to each, it is possible to directly transmit the data to each device.

Further, according to the processing in the device on the data transmission side according to the present invention, the main system side in the multiplex system device is referred to by referring to the stored contents in which the state of the communication partner is stored in advance. Transmit data to the device.

Therefore, the processing for recognizing the state of each device forming the multiplex system device each time data is transmitted is unnecessary.

In addition, if a process of confirming the state of the multiplex system device from the transmitting device is performed once when the state of the multiplex system device which is the communication destination changes and the data communication is abnormal, thereafter, the multiplex system There is no need to perform a process of checking the state of each device constituting the device each time data is transmitted.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a network configuration example for explaining an embodiment of the present invention.

Reference numerals 302 and 303 denote devices 307, respectively.
And a dual system device including the device 308, the device 309, and the device 310.

The device 307 and the device 308, or the device 309 and the device 310 are assumed to be capable of arbitrarily switching the main system and the sub system, and the device 301 is
It has a function of transmitting data to each duplex system.

Of course, the device 301 may be one of the dual system devices.

Loops 304 and 3 for each network
05 is connected via a coupling device 306 such as a router, and data transmission is reliably performed.

As the communication address, a port number pre-assigned to each device is used, and in the dual system device, a logical representative port number is pre-assigned and used as a communication address. That is, in the dual system device, the port number is assigned to the dual system device itself in addition to the respective devices that are the primary system and the secondary system.
FIG. 1 shows a functional block diagram of the transmission device.

In FIG. 1, computers are connected via a network. As the network, for example, a LAN (local area network) using an optical fiber as a communication means can be realized.

The computer comprises a communication control unit, a state management table, and a user program.
These are realized by, for example, a main storage unit in a computer and a program stored therein.

The user program is, for example, various application programs, and has a function of requesting the communication control unit for data transmission processing.

When the communication partner is a duplex system device, the communication controller determines whether each device constituting the duplex system device is a master system or a slave system, and the communication partner state management. Function, data transmission processing function of transmitting data to the corresponding device, and status information of the corresponding communication partner in which a failure occurs when a communication failure occurs (information such as master system or slave system) It has a fault detection function that erases. Although not shown, data transmission is performed according to a predetermined communication protocol.

The status management table stores the status (information such as master system or slave system) of each device constituting the duplex system device when the communication partner device is the duplex system device. The contents thereof are referred to when the communication partner state management function is activated, and are updated when the failure detection function is activated.

Similarly, FIG. 2 shows a receiver (duplex system).
The functional block diagram of is shown.

FIG. 2 shows a computer A via a network.
1, A2 are connected. As the network, for example, a LAN (local area network) using an optical fiber as a communication means can be realized.

The computer A1 comprises a communication control unit, a state management table, and a user program. These are realized by, for example, a main storage unit in a computer and a program stored therein. Calculator A2
Is realized by a configuration similar to that of the computer A1.

The user program is, for example, various application programs, and has a function of receiving the data sent from the transmission source.

Although not shown, the communication control unit determines a data reception processing function for receiving data and whether the own device is a master system or a slave system according to a predetermined communication protocol. It has a self-device status acquisition function, a status notification function of transmitting data with the status of the self device to a communication partner (data transmission source), and a failure detection function of detecting a failure during communication.

The status management table is means for storing the status of whether the self apparatus is the master system or the slave system, and the contents thereof are updated and referred to by the activation of the self apparatus status acquisition function. Further, FIG. 11 illustrates how information is transferred between the transmitting and receiving devices in the first embodiment of the present invention.

First, consider the case where data is transmitted from the device 301 to the duplex device 303.

With reference to FIG. 6, a processing procedure by the transmitting side device up to data transmission will be described.

First, in step 601, the device type of the communication partner is identified based on the communication address of the designated device. If the communication destination address is not the representative address of the duplex system device, do not change the specified address,
Go to step 608.

Next, in step 602, when the communication destination address is a representative of the duplex system device (3 as the communication destination)
(When 03 is specified), the contents of the status management table, which is stored in advance in the own device and manages the information of the master / slave status of the communication partner, is referred to.

It is confirmed whether or not the information regarding the corresponding device is held in the state management table, and if the information is held, the process proceeds to step 607.

In step 603, a "POINT TO POINT line" (a line constituted by so-called point-to-point links is referred to as below) is opened for inquiry to both systems. In this embodiment,
As a protocol (communication protocol) when using the "POINT TO POINT line", TCP / IP (Tra
nsmission Control Protocol
1 / Internet Protocol).

This protocol is a transmission control protocol that provides high reliability and one-to-one communication. It may be configured to have a transmission error check function, an error resend function, and the like.

In "TCP / IP", it is necessary to establish a virtual communication path (connection) between the transmitting and receiving devices before data communication.

Both systems (301-309 and 301-
Opening a "POINTTO POINT line" for 310) means establishing a connection between the devices 301 and 309 and the devices 301 and 310.

In step 604, an information frame for inquiring the device status (status indicating whether the system is the master system or the slave system) is transmitted to both systems using the line opened in step 603. To do. This corresponds to 1101 in FIG.

In step 605, the response information in which the status of each device is given is received from both systems. However, since the life or death status (whether or not it is broken) of the communication partner is unknown,
Since it is not possible to grasp the timing at which the response information is sent, in this step, a process in which the response information may be sent at any time, for example, until the response information of the device is received,
Processing such as weighting is included. This corresponds to 1102 in FIG. In step 606, based on the response information obtained in step 605, the information is stored in the state management table of the master / slave state of the communication partner existing in the own device.

In step 607, the content of the master / slave status management table is referred to and the representative communication address is converted into the communication address of the corresponding master device.

In step 608, the "POINT TOPOINT line" is opened based on the communication address, and the data transmission process is performed. This corresponds to 1103 in FIG.

In FIG. 5A, "POINT TO P
An image diagram of data transmission using the "OINT line" is shown.

Now, referring to FIG. 7, the device (3
09, 310, etc.) in the receiving device. In step 701, “POINT TO
Open the "POINT line" and request to establish a connection. This corresponds to 1101 in FIG.

Next, in step 702, inquiry information from the transmitter is received. Next, in step 703, the state management table in the own device is referenced to perform the process of acquiring the state of the own device (whether it is the master system or the slave system). At this time, the sender device has specified
It is also possible to perform processing such as checking with the status of the duplex system (main system or slave system).

At step 704, the process of transmitting the response data to the transmission inquiry destination is performed. This is
1 corresponds to 1102.

After transmitting such data, a process of continuing the wait until the connection is released or the actual data information is received is performed.

As described above, thereafter, data transmission to the main system side of the dual system device can be efficiently performed by one transmission unless an abnormality such as system switching occurs in the dual system device. .

The processing when a communication abnormality occurs will be described below.

FIG. 8 shows the processing procedure.

First, in step 801, a process for detecting the occurrence of an abnormal transmission of the user's data information frame is performed. This step includes a process corresponding to a state change of the device that can be detected in advance, such as advance notification by the monitoring function of the system such as stopping of the communication partner device.

Next, in step 802, processing for identifying the device in which the communication abnormality has occurred is performed. At this time, it is determined whether or not the device in which the communication error has occurred is the dual device.

At step 803, the corresponding state management table of the duplex system device in which the communication abnormality has occurred is erased and returned to the initial state.

At step 804, notification processing such as alarm output is performed according to the content of the abnormality.

After that, the data transmission to the corresponding duplex system device can be performed again by the same procedure as the procedure from step 601 described above.

Next, as a second embodiment according to the present invention, a process for transmitting data from the device 301 to the duplex system device 302 belonging to the same network will be described as an example.

Although the data can be transmitted by the means described in the first embodiment, in this embodiment, the data can be transmitted without the transmitting device knowing the partner device in advance. I will describe.

FIG. 12 illustrates how information is transferred between the transmitting and receiving devices in the second embodiment of the present invention.

FIG. 9 shows the processing procedure of the transmitting apparatus.

First, in step 901, the multicast line is opened.

In this embodiment, "UDP / IP" (Use) is used as a protocol when using a multicast line.
r Datagram Protocol / Inter
Net Protocol).

This protocol is generally unreliable because there are unprepared procedures in the transmission control (for example, there is no transmission error check function, no retransmission function at the time of error, etc.).

However, since the connection is not established between the transmitting and receiving devices, the information frame can be transmitted to a plurality of devices by one transmission. On the other hand, “TCP / IP” requires multiple transmissions.

Next, in step 902, the line opened in step 901 is used to transmit the inquiry information to a plurality of devices by multicast.

Here, FIG. 5B shows an image diagram of multicast transmission.

The information frame transmitted from the device 301 is simultaneously transmitted to the devices 307 and 308 as well as other devices belonging to the same network. This corresponds to 1201 in FIG.

Next, in step 903, the receiving device which has received the data in step 902 makes a request for establishing a connection that the data has been received,
In addition to notifying the transmitting device, the state of the device itself is acquired and the transmitting device is notified of the state. Generally, the side that makes a connection establishment request is called a “client”, and the side that accepts a connection connection request is called a “server”.

That is, the receiving side becomes the client and opens the "POINT TO POINT line".

As a result, unlike the first embodiment, the transmitting device can know the states of a plurality of duplex system devices at a time, and it is not necessary to know the state of the partner device in advance before transmission. , System scalability is improved.

In the processing here, the transmitting device can acquire a specific address of the communication destination, and thereafter, the processing can be performed based on the address. In FIG.
This is a process corresponding to step 605, and corresponds to the response of the data indicated by 1202 in FIG.

Next, in step 904, the obtained information is stored in the state management table based on the response information. That is, the process corresponding to step 606 shown in FIG. 6 is performed. Next, in step 905, the same processing as steps 607 to 608 in FIG. 6 is performed. That is,
Send data to the corresponding device. In FIG. 12, 1
Corresponding to 203.

After that, the data transmission to the main system device of the dual system device can be performed only once unless the system is switched in the dual system device and the state is changed.

Next, FIG. 10 shows a processing flow on the receiving side.

First, in step 1001, step 9
The multicast line is opened corresponding to the processing of 01.

Next, in step 1002, the multicast data (inquiry information) sent by the processing of step 902 is received. This corresponds to 1201 in FIG.

Next, in step 1003, based on the inquiry information data received by the processing of step 1002, the state of the own device is referred to the state management table, and a connection establishment request is issued to the transmitting device. do. This corresponds to 1202 in FIG.

Next, at step 1004, the same processing as the processing at step 704 is performed. This is shown in FIG.
Corresponds to 1203.

At the time of abnormality, the above steps 801 to 8 are executed.
This can be dealt with by performing the same processing as 04.

As described above, thereafter, for data transmission to the main system side of the dual system device, by referring to the state management table, unless the communication error occurs, the corresponding device is sent to the "POI".
This can be done using the "NTTO POINT line".

However, in the second embodiment, since the inquiry to both systems is made by the multicast line, the target range is limited to the same network, and the reliability is the first.
Inferior to the example of.

Further, in each of the embodiments, the case where the device 306 is configured by a router or the like and it is not necessary to be aware that the network connection device exists as a relay device has been described. If it is necessary to be aware that it is configured as a gateway and exists as a relay device, the transmission device 301 stores the presence of 306 as a relay device in the state management table, and the device 306 The same processing as that performed at the time of data transmission from the transmission device to the heavy system device may be performed. Here, the operation according to the present embodiment described above and the operation according to the conventional technique described above will be compared.

As described in the prior art, when a transmission control device or the like is provided between the duplex system on the receiving side and the network, the transmission control device has to perform relay processing once. Therefore, if the transmission control device is stopped, data cannot be transmitted.

Further, periodically to the transmission control device,
It is necessary to notify the device status information (information as to whether it is the master system or the slave system) from the duplex system device.

Furthermore, in the method in which the multiplex system device itself notifies the status of its own device, it is unavoidable that information is transmitted to the wrong device when a situation in which status notification cannot be performed occurs.

On the other hand, according to the present embodiment, since the transmitting device automatically confirms the status with the duplex system device before transmitting,
It is possible to perform transmission to a target main system device without using a transmission device for relay. In addition, it is not necessary to periodically notify the status from the dual system device, and the communication load can be reduced. Of course, in normal communication, data can be transmitted to the target main system device in one communication, and the load on the network can be reduced.

Lastly, although the present embodiment has been described by taking the dual system device as an example, a multiple system device such as a triple system device which constitutes a multiple system by one main system device and a plurality of standby system devices. It goes without saying that the same can be applied to the above.

[0106]

As described above, according to the present invention, it is possible to communicate from another device to the main system device of the multiplex system device without recognizing the multiplexing configuration of the multiplex system device. A communication method can be provided.

[Brief description of drawings]

FIG. 1 is an example of functional blocks in a transmission device when the present invention is implemented.

FIG. 2 is an example of functional blocks in a transmission device when the present invention is implemented.

FIG. 3 is a configuration of an entire system for explaining an embodiment of the present invention.

FIG. 4 is a configuration diagram for explaining an example of a conventional technique.

FIG. 5: Multicast, POINT TO POIN
It is explanatory drawing of T transmission.

FIG. 6 is a flowchart showing a processing procedure on the transmitting side in an embodiment (first embodiment) of the present invention.

FIG. 7 is a flowchart showing a processing procedure on the receiving side in one embodiment (first embodiment) of the present invention.

FIG. 8 is a flowchart showing a processing procedure when a communication abnormality occurs in the embodiment of the present invention.

FIG. 9 is a flowchart showing a processing procedure on the transmission side in an embodiment (second embodiment) of the present invention.

FIG. 10 is a flowchart showing a processing procedure on the receiving side in one embodiment (second embodiment) of the present invention.

FIG. 11 is an explanatory diagram of information frame exchange between the transmission / reception devices in the embodiment (first embodiment) of the present invention.

FIG. 12 is an explanatory diagram of information frame exchange between the transmission / reception devices in one embodiment (second embodiment) of the present invention.

[Explanation of symbols]

301 ... Device, 302 ... Duplication device, 303 ... Duplication device, 304 ... Loop, 305 ... Loop, 306 ... Router, etc.

Claims (7)

[Claims] 1. A data transmission method between devices in a network system in which a plurality of devices, at least one of which is a dual system device, are connected via a communication means, wherein a port number is predetermined for the device. Further, when the device is a dual device, the port numbers are set in advance for the two devices forming the device, and the representative port number is also set for the dual device itself. In advance, each device stores state information indicating whether each of the two devices constituting each duplex device connected to the network system is a master system or a slave system. In the data transmission, when the representative port number is used as the data communication address, the representative port number is converted into the port number of the main system device based on the status information, and the data is transmitted. , Double Communication method for a network system including the apparatus. 2. The status information according to claim 1, wherein each of the devices inquires of two devices constituting each duplex device connected to the network system when the network system is started up. A method for communicating with a network system, including a dual system device, characterized in that whether or not the main system is checked and stored. 3. The communication method for a network system including a dual system device according to claim 2, wherein the status information is updated at a predetermined time. 4. The method according to claim 1, 2 or 3,
A communication method, wherein the state information is managed by a data transmission source. 5. The method according to claim 3, wherein the predetermined time is when a data transmission abnormality occurs. 6. The change of status information indicating whether the system is a master system or a slave system, which should be stored, corresponding to the master-slave status of the two devices constituting the dual system device according to claim 3. A communication method for a network system including a dual system device, which is characterized in that the status information is updated when the conditions match. 7. A method of data transmission between devices in a network system, wherein at least one of which is a dual device is connected via a communication means, wherein a port number is predetermined for the device. Further, when the device is a dual device, the port numbers are set in advance for the two devices forming the device, and the representative port number is also set for the dual device itself. When data is transmitted from one device to another device in advance, at least one of the port number and the representative port number is used as the data communication address, and the data is transmitted with the data communication address as the transmission destination. A communication method for a network system including a dual device.