JPH07114410B2 - Storage and switching network control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control system for a storage switching network.

[Prior Art] For example, when a data transmission network is prepared by using a line network such as a public telephone line network, a center having a function larger than that of a data terminal device rather than operating each data terminal device independently. By installing a station device (for example, a storage exchange device) and using the function of this center station device for each data terminal device, it is possible to use a smaller function as each data terminal device. Overall, it is economically advantageous.

Furthermore, such a center station device is provided in each remote place, and each center station device performs the service of the area in the remote place, and these center station devices are connected by a network such as a digital high-speed line network. Interconnection allows large-scale networks to be efficiently constructed.

Now, for example, in the case of performing broadcast transmission for transmitting the same message (data) to a plurality of destinations using such a network, a center station device (hereinafter referred to as a transmission side device) to which a data terminal device on the transmission side is connected. The transmission data is transmitted from the center station device) to the center station device (hereinafter, referred to as the reception side center station device) to which the respective destinations are connected, and is temporarily stored in the reception side center station device.

Then, the accumulated transmission data is transmitted from the receiving side center station device to each destination data terminal device.

By the way, the receiving side center station device conventionally holds the data received from the transmitting side center station device to some extent for a long period of time so that the destination data terminal device can cope with the need to receive the received data again. Was doing.

However, in such a conventional method, since the same telegram (transmission data) is held in a plurality of receiving side center station devices for a long time, resources (memory capacity in this case) in the entire network are not effectively used. That caused the inconvenience.

[Purpose] The present invention has been made in order to solve the disadvantages of the prior art, and an object of the present invention is to provide a control system of a storage switching network that can effectively use network resources.

[Structure] In order to achieve this object, the present invention holds transmission data from a transmitting terminal device for a predetermined transmitting side holding period in a transmitting side storage exchange device to which a transmitting terminal device is connected, and connects to a receiving terminal device. The receiving-side storage / exchange device holds the transmission data for a predetermined receiving-side holding period, and the receiving-side storage / exchange device
When the receiving terminal device requests the retransmission of the transmission data, when the requested transmission data is not held, the corresponding transmission side storage / exchange device is requested to retransmit the transmission data.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a facsimile transmission network according to an embodiment of the present invention.

In the figure, this facsimile transmission network includes two sub-networks SNaTa and SNTb and these sub-networks S.
It consists of a communication line LN that interconnects NTa and SNTb. The communication line LN is composed of, for example, a high-speed digital line network or a dedicated line.

Subnetwork SNTa includes a public switched telephone network PSTNa, this a public switched telephone network PSTNa connected to k-number of the facsimile apparatus FXa ₁ ~FXa _k, store and connected by a plurality of lines to the public telephone network PSTNa It consists of the device SAFa.

The sub-network SNTb is a public telephone line network PSTNb, m facsimile machines FXb _{1 to} FXb _{m connected} to the public telephone line network PSTNb, and storage exchanges connected to the public telephone line network PSTNb by a plurality of lines. It consists of the device SAFb.

The storage / switching devices SAFa, SAFb forming these sub-networks SNTa, SNTb are interconnected by a communication line LN, and these storage / switching devices SAFa, SAFb are connected.
Data transmission between each other is realized via this communication line LN.

Here, the sub-networks SNTa and SNTb are configured in mutually distant locations within the same country, or are configured in different countries. In the former case, the public telephone line networks PSTNa and PSTNb are configured by, for example, closing one public telephone line network in the same country.

An example of the storage exchange device SAFa is shown in FIG. Note that the other storage and switching device SAFb has a similar configuration.

In the figure, the system control unit 1 is the storage exchange device.
Through the communication control unit CCU that controls the entire SAFa and also controls the data transmission to and from the storage and switching device SAFb that is executed via the communication line LN, and the i lines that connect to the public telephone line network PSTNa. Facsimile communication control unit for exchanging data with the facsimile devices FXa _{1 to} FXa _k
The FCU1 to FCUi are controlled appropriately.

The magnetic storage device 2 is for storing various information such as transmission information and transmission condition information received from the facsimile devices FXa _{1 to} FXa _k and the storage exchange device SAFb, and is for recording / reproducing data on / from a magnetic disk. Magnetic disk unit 2a
And a magnetic disk controller 2b for controlling data input / output of the magnetic disk device 2a. The operation display unit 3 is composed of an input device such as a keyboard and a display device such as a screen display device necessary for operating the storage exchange device SAFa.

This storage exchange device SAFa can realize various functions such as re-transmission, re-reception, confirmation of contents, change of destination, and cancellation of image information stored in the magnetic storage device 2.
It also has a function of appropriately editing image information. The operation display unit 3 is used during this image editing.

Further, the storage and exchange device SAFa holds the data received from the other storage and exchange device SAFb in the magnetic storage device 2 for a predetermined receiving side holding period, and also transmits the data transmitted to the storage and exchange device SAFb in a predetermined transmission. It is held in the magnetic storage device 2 only for the side holding period. In this case, the receiving side holding period is set to be shorter than the transmitting side holding period.

An example of the facsimile machine FXa ₁ is shown in FIG. Note that the other facsimile machines FXa _{2 to} FXa _k and FXb _{1 to} FXb _m are also configured in the same manner.

Facsimile device FXa ₁ is a well-known facsimile terminal device FX that transmits and receives image information via the public telephone line network PSTNa.
And an operation terminal device DS for transmitting and receiving data requesting various services to the storage exchange device SAFa.

Therefore, the operator operates the operation terminal device DS to re-send, re-receive image information to the storage exchange device SAFa,
It is possible to request confirmation of contents, change of destination, cancellation, and the like.

With the above configuration, the storage and exchange devices SAFa and SAFb provide the storage and exchange service to the facsimile devices constituting the sub-networks SNTa and SNTb, respectively.

Further, when there is a data transmission request to a facsimile device belonging to a different sub-network, the transmission data is transmitted to the target facsimile device via the communication line LN to the storage / exchange device of the sub-network to which the destination facsimile device belongs. Ask for relay. Also, a large number of destinations can be designated for the same subnetwork.

That is, for example, when the fax machine FXa ₁ of the sub-network SNTa broadcasts to all other fax machines FX _{2 to} FX _k of the same sub-network SNTa, the fax machine FX ₁ broadcasts to the storage exchange SAFa. Is transmitted and the image information is transmitted to the storage and switching device SAFa in a state where the destination at that time is specified. However, in this case, when the destination is specified, for example, if specific destination information representing "all other facsimile devices in the same subnetwork" is set in advance, the destination information is stored in the storage switching device SAFa.
All you have to do is notify. Also, these destination information can be input from the operation terminal device DS.

As a result, the storage / exchange device SAFa temporarily stores the designated destination and image information in the magnetic storage device 2, transmits the image information to the destination when a call is made to one destination, and the information is transmitted to all the destinations. Repeated broadcast transmission is performed for the specified destination. Furthermore, it is also possible to specify the time when the storage and switching device SAFa starts the broadcast transmission. Then, the image information transmitted in this way is held in the magnetic storage device 2 only for the transmission side holding period.

Also, for example, a facsimile machine of the sub-network SNTa
FXa ₁ is a fax machine FXb _{1 of} subnetwork SNTb
When transmitting the image information to the facsimile machine FXa ₁ , the facsimile device FXa ₁ uses the data representing the subnetwork SNTb as the destination information and the public telephone network PSTN in the subnetwork SNTb.
The image information is transmitted to the storage / exchange device SAFa in a state where the data representing the telephone number of the facsimile device FXb _{1 in} b is continuously specified.

As a result, the storage exchange device SAFa temporarily stores the destination information and the image information in the magnetic storage device 3, and first calls the storage exchange device SAFb of the sub-network SNTb by the communication line LN.
The storage / exchange device SAFb is requested to perform relay transmission with the telephone number of the facsimile device FXb ₁ in the public telephone line network PSTNb designated as relay destination information, and the accumulated image information is transmitted.

As a result, the storage / exchange device SAFb temporarily stores the specified destination and image information in the magnetic storage device 3, and the facsimile device
Calls FXb ₁ and transmits the image information stored at that time.

In this way, data transmission between different sub-networks is performed. In addition, in this case, the storage exchange device SAFa
Holds transmission data for the holding period of the transmitting side, and the storage and switching device SAFb holds transmission data for the holding period of the receiving side.

When image information is transmitted between different sub-networks in this way, the received image information includes the file number in the storage exchange device of the sub-network to which the receiving-side facsimile device belongs and the transmitting-side facsimile device. Two types of file numbers, that is, file numbers in the storage / exchange apparatus of the subnetwork to which the transmission-side facsimile apparatus belongs, and identification information of the storage / exchange apparatus to which the transmitting-side facsimile apparatus belongs are added.

In addition, at the time of one broadcast transmission, for example, "subnetwork
SNTa facsimile machine FXa ₁ , FXa ₂ , sub-network S
It is also possible to specify multiple destinations across different sub-networks, such as NTb fax machine FXb _(m-1) , FXb _m ". At that time, subnetwork SNTa, SNTb
In the storage switching devices SAFa and SAFb, the destination information relating to the sub-network SNTa and SNTb and the image information to be transmitted are stored, and the sub-network SNTa and SNTb are stored.
The image information is broadcast-transmitted to the destination designated by.

Here, if the facsimile device that transmitted the data belongs to the sub-network SNTa, the storage exchange device SNTa
Holds the transmission data for the sending side holding period, and the storage and switching device SNTb holds the transmission data for the receiving side holding period. If the facsimile device that sent the data belongs to the sub-network SNTb, the storage exchange device
The SNTa holds the transmission data for the receiving side holding period, and the storage and switching device SNTb holds the transmission data for the sending side holding period.

In this way, the subnetwork via the communication line LN
Data transmission is performed between SNTa and SNTb, and they act as one network as a whole.

Now, from the fax machine FXa ₁ to the fax machine FXb ₁
Suppose that the image information is transmitted to the facsimile apparatus FXb ₁ and requests the storage / exchange apparatus SAFb to re-receive the image information. At the time of this re-reception request, the image information to be re-received is specified by the two file numbers attached to the received image information, and the identification information of the storage exchange device to which the transmitting-side facsimile device belongs is added. It is a store-side switching device on the sending side. Also, set the file number of the storage exchange device in the subnetwork to which you belong to 1
Second, set the file number of the storage exchange device in the sub-network to which the sending facsimile machine belongs to 2
The second file number is stored in the storage exchange device SA.
Fb can be distinguished.

As a result, as shown in FIG. 4, the storage / exchange device SAFb first sends the message (image information) requested to be re-received based on the file number added by itself among the file numbers notified at the time of requesting re-reception. ) Is held (decision 401).

At this time, if the receiving side holding period has not passed since the message for which re-reception was requested and the message is held (the result of judgment 401 is YES), the facsimile device FXb ₁ of the re-requesting request source The electronic message is transmitted to (step 402). In addition, before retransmitting the message, the facsimile device is notified that the message can be retransmitted.
Notify FXb ₁ . As a result, immediately before the message is re-received, the fact that the message can be re-received is displayed on the operation terminal device DS of the facsimile apparatus FXb ₁ .

In addition, when the receiving side holding period has passed and the message for which re-reception is requested is not held (result of judgment 401 is NO),
The storage exchange apparatus SAFb inquires of the transmission side storage exchange apparatus SAFa whether the message can be re-received by designating the file number of the storage exchange apparatus SAFa (process 403).

As a result, from the storage exchange apparatus SAFa, the identification information indicating whether or not the designated electronic message is held is notified, and when the electronic message is held, the electronic message is retransmitted (to be described later). ).

Therefore, it is determined whether the message can be re-received based on the result of the inquiry (decision 404), and the result of the determination 404 is NO.
When it becomes, the fact that the electronic message cannot be retransmitted is notified to the facsimile apparatus FXb ₁ (process 405). This allows
The fact that the message cannot be received again is displayed on the operation terminal device DS of the facsimile device FXb ₁ .

Further, when the result of the determination 404 is YES, the electronic message transmitted from the storage exchange device SAFa after that is transmitted to the facsimile device.
It is transmitted to FXb ₁ (process 406). Also in process 406, similar to process 402, the facsimile device FXb ₁ is notified that the message can be retransmitted before the message is retransmitted.

Storage and switching device on the receiving side (in this case, storage and switching device SAF
When an inquiry is made by the process 408 executed by b), the storage-and-exchange device on the transmitting side (in this case, the storage-and-exchange device SAFa) executes the process of FIG.

That is, first, based on the file number notified from the receiving side storage / exchange device, it is checked whether or not the electronic message (image information) requested to be re-received is held (decision 501).

At that time, if the sending side holding period has not passed since the message for which re-reception was requested, and the message is held (the result of judgment 501 is YES), it is stored on the receiving side that the message can be retransmitted. After notifying the exchange device (process 502), the electronic message is transmitted to the storage exchange device (process 503).

Further, when the transmission-side holding period has passed and the message requested to be retransmitted is not retained (the result of determination 501 is NO), the storage-exchange device on the reception side is notified that the message cannot be retransmitted (process 542). ).

In this way, when the receiving facsimile machine requests to re-receive the electronic message (image information), if the receiving-side storage / exchange device holds the electronic message, the electronic message is immediately retransmitted.

Further, when the storage / exchange apparatus on the receiving side does not hold the storage / exchange apparatus on the receiving side, it is inquired of the storage / exchange apparatus on the transmitting side whether or not the designated message can be retransmitted.

When the storage-side switching device on the transmitting side can retransmit,
The specified electronic message is retransmitted from the storage-side switching apparatus on the sending side to the storage-and-switching apparatus on the receiving side, and is further transmitted to the facsimile apparatus that has requested the re-reception.

When the re-reception of the electronic message cannot be realized, the operator of the facsimile device on the receiving side may request the operator of the facsimile device on the transmitting side to retransmit the electronic message.

By the way, a receiving side holding period is set as a period during which the receiving side storage / exchange device holds image information (telegram; transmission data), and a period during which the transmitting side storage / exchange device holds image information. The transmission side holding period is set to a period in which the number of electronic messages in the entire network is reduced and the serviceability of the network to the data terminal device (facsimile device) is not deteriorated. At this time,
While actually operating the network, it is possible to find the most suitable period by appropriately changing the retention period.

Although the facsimile device is used as the terminal device in the above-described embodiments, the present invention can be applied to the case of using a terminal device other than this.

Further, in the above-mentioned embodiment, one network is formed by two sub-networks, but the number of the sub-networks is not limited to that. If the storage-side switching device on the receiving side can specify the file number added by the storage-side switching device on the transmitting side from the file number added by itself, the file number specified at the time of re-receiving can be set to one. it can.

Furthermore, the structure of the storage exchange device is not limited to the above-mentioned one.

[Effect] As described above, according to the present invention, transmission data from the transmission terminal device is held in the transmission side storage exchange device to which the transmission terminal device is connected for a predetermined transmission side holding period, and the reception terminal device is connected. The receiving-side storage / exchange device holds the transmission data for a predetermined receiving-side holding period, and the receiving-side storage / exchange device
When the receiving terminal device requests retransmission of the transmission data, and when the requested transmission data is not held, the corresponding transmitting side storage switching device is requested to retransmit the transmission data, so the network resources are validated. Get the advantage of being available.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a facsimile transmission network according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of a storage exchange device, FIG. 3 is a block diagram showing an example of a facsimile device, and FIG. Is a flowchart showing a processing example of the receiving side storage / exchange apparatus, and FIG. 5 is a flowchart showing a processing example of the transmitting side storage / exchange apparatus. LN ... communication line, SNTa, SNTb ... subnetwork, SAF
a, SAFb ... Store and exchange device, PSNa, PSTNb ... Public telephone network, FXa _{1 to} FXa _k , FXb _{1 to} FXb _m ...... Facsimile device,
1 ... System control unit, 2 ... Magnetic storage device, 3 ... Operation display unit, CCU ... Communication control unit, FCU1 to FCUi ... Facsimile communication control unit, FX ... Facsimile terminal device, DS ...
... Operating terminal device.

Claims (2)

[Claims] 1. A storage and switching network comprising a plurality of storage and switching devices for providing a storage and switching service to a plurality of terminal devices scattered in a predetermined area, the storage and switching devices being interconnected by a line network. In the method, the transmitting-side storage / exchange device connected to the transmitting-side terminal device holds the transmission data from the transmitting-side terminal device for a predetermined transmission-side holding period, and the receiving-side storage / exchange device to which the receiving-side terminal device connects. The device holds the transmission data for a predetermined receiving side holding period, and when the receiving side storage switching device requests transmission data retransmission from the receiving side terminal device, when it does not hold the requested transmission data. , A storage / switching network control method characterized by requesting a corresponding storage / switching device on the transmitting side to retransmit the transmission data. 2. The storage / switching network control system according to claim 1, wherein the receiving side holding period is set shorter than the transmitting side holding period.