JP2750923B2 - Network connection failure avoidance method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure avoidance method suitable for a network connection failure in a data terminal device connected to a packet switching network.

[Conventional technology]

In the conventional device, even if the called data terminal device is in a failure or busy state, a call is made only to the called data terminal device address. It is possible.

It should be noted that the private branch exchange in the general exchange telephone network has a function of calling another telephone when the other telephone is busy as a function of the exchange.

[Problems to be solved by the invention]

The above-mentioned prior art does not take into consideration the case where the partner data terminal apparatus is disconnected or the busy state continues, and if these states continue, transmission data cannot be transmitted during that time.

An object of the present invention is to enable data transmission by connecting to a communicable data terminal device while avoiding a partner data terminal device incapable of communication.

[Means for solving the problem]

The present invention is a network connection failure avoidance method including a packet switching network and a data terminal device connected to the packet switching network, wherein the data terminal device has a packet connection control procedure for connecting to the packet switching network, A registering means for registering a plurality of destination data terminal addresses when a call is made; and, when communication with the destination data terminal fails, a network connection is established and another destination data terminal is automatically connected to. And a procedure for calling again.

[Action]

By making it possible to register a plurality of addresses of the called data terminal device in the calling data terminal device, it is possible to arbitrarily register a partner DTE to be connected instead of the case where connection becomes impossible.

In addition, automatic recalling means sequentially uses the registered data terminal device addresses for recalling, so that no manual operation is required until the connection is established.

Furthermore, by using the calling data terminal device address in the incoming call packet, a call can be made to a data terminal device in which no failure has occurred, so that the connection can be reliably established.

〔Example〕

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

 FIG. 1 is a diagram showing the overall configuration of the present system.

In FIG. 1, reference numerals 1 and 2 denote G3 facsimile, and image information of a document input from this is stored via a telephone network in the case of 1, directly in the facsimile terminal control device in the case of 2, and from 4 to 5 And stored in the storage and exchange control device 6 via the packet network of. Further, it is output to the G4 facsimile 7 designated at the time of transmission from 6 to 1 or 2. The present invention is a procedure for avoiding a network connection failure when transmitting image information of a document from 4 to 6.

FIG. 4 shows a configuration diagram for registering an incoming data terminal (hereinafter referred to as DTE) address used for automatic re-calling at the time of a network connection failure. The data input unit 8 is composed of a command key, a data key, and a display unit.
The address is input, and the main control unit 9 registers in the DTE address registration area 10.

2 and 3 show a procedure for avoiding a failure in the event of a network failure.

FIG. 2 shows that when the facsimile terminal control device of 4 transmits the image information 12 from the G3 facsimile of 1 or 2 to the storage and switching control device of 6, when the DTE address of the called party has a failure, there is no failure. This is a procedure for automatically re-calling using the DTE address registered in the registration area 10 up to the DTE address. First, the facsimile terminal control device 4 that has received the image information 12 issues a call request 13 from the main control unit 9 to the network control unit 11, and thereby issues a call request (CR) packet 14 to the packet network 5. I do. The incoming DTE address at that time is “DTE1” registered in the DTe address registration area.
Use 16. The packet network 5 issues an incoming call (CN) packet 15 to “DTE1” of the storage and switching control device 6, but rejects it with a recovery request (CQ) packet 20 because of a failure. When the facsimile terminal controller 4 receives the disconnection instruction (CI) 21 from the packet network 5, it transmits a recovery confirmation (CF) packet 22 and the connection is abnormally disconnected. Then the network control unit 11
Is the next “DTE” registered in the DTE address registration area 10.
Automatically re-call the CR packet 23 using 2 "17. Similarly, if there is a failure and the call is disconnected, the re-call will be made again using" DTE3 "18 and a CR packet 24 will be issued.
If there is no failure in "DTE3", the connection completion (CC) packet 25 is received from the packet network 5, and communication is normally performed thereafter. When the communication ends, the end 26 is reported to the main control unit 9,
The next image information 27 is transmitted, and the CR packet 28 at that time is transmitted.
The “DTE3” 18 is used as the DTE address to be added to “.

As described above, when the called DTE address cannot be connected due to a busy state or a failure, the automatic re-calling can be performed within the registered DTE address range, and the communication can be completed with the communicable DTE address.

FIG. 3 is a diagram showing an outgoing call of the CN packet 29 when there is an incoming call from the store-and-forward controller 6 during the automatic recall in FIG.
This is a procedure for calling again using the DTE address.

As shown in FIG. 2, after the second CR packet 23 is issued, and after disconnection due to a failure, the CN packet 29 from the storage and exchange control device 6 is received, the added calling DTE address becomes the DTE address. Checks if it is registered in registration area 10, and if it is registered, the next DTE to recall
Since the address "DTE4" does not have a failure, it ends normally,
The end 26 is reported to the main control unit. Thereafter, communication is possible until “DTE4” becomes faulty or busy.

FIG. 5 shows the sequence when a failure occurs in a higher order procedure, while FIG. 2 and FIG. 3 show the sequence at the time of a failure at the network level.

When the activation by the call request 13 causes a CR packet 23 to cause a DTE address with no network failure and a higher-level procedure error 33 after connection, the network is normally disconnected and an end 26 is reported to the main controller 9. After that, a CR packet 24 is issued using “DTE3” 18 upon activation by a call request 31 as a retry,
If the processing ends normally, the end is reported to the main control unit 32, and the communication is completed.

〔The invention's effect〕

According to the present invention, even if the destination DTE is in a failure or busy state, if the DTE is registered in advance in the device, a communicable DTE can be detected and communication can be performed. Is shortened. Also, the occupancy of the source terminal is reduced.

[Brief description of the drawings]

FIG. 1 is an overall system configuration diagram of the present invention, FIG. 2 is a sequence diagram for explaining an operation for automatically updating a calling data terminal device address sequentially and re-calling, and FIG. 3 is added to an incoming call packet. Sequence diagram illustrating the operation when automatically re-calling using the calling data terminal device address,
FIG. 4 is a diagram showing a configuration at the time of registering a data terminal device address, and FIG.
The figure is a sequence diagram for explaining a recall operation when a communication failure occurs at a higher level than the network. 1,2: Document transmission group 3 facsimile (G3 facsimile), 3: Telephone network, 4: Facsimile terminal control device, 5: Packet switching network, 6: Storage and switching control device, 7: Text reception Group 4 facsimile (G4 facsimile), 3 Network controller, CR Call request packet, CN Call packet, CI Call disconnection packet, CQ
…… Recovery request packet, CF …… Recovery confirmation packet, CC…
… Connection complete packet, CA …… Call acceptance packet, DT ……
Data packet.

Claims (3)

(57) [Claims] 1. A source data terminal device, a plurality of destination data terminal devices, and a packet switching network connecting these data terminal devices. In a network connection failure avoidance system configured so that a data terminal device and one of the plurality of destination data terminal devices are communicatively connected, the source data terminal device connects to the packet switching network. Packet connection control means, registration means for registering a plurality of addresses for each of the plurality of destination data terminal apparatuses, the registration means being an address used when calling the destination data terminal apparatus; If there is a failure in the communication connection with one of the destination data terminal devices, the address of the other destination data terminal device registered by the registration means Re-calling by the selected address, re-call control means for making a communication connection with the other destination data terminal device, and when the communication connection with the destination data terminal device ends normally, Storage means for storing an address of a destination data terminal device for which communication connection has been normally completed; and when making a new call to the destination data terminal device, extracting an address stored in the storage means; And a call control means for calling based on the extracted address. 2. The transmission source data terminal device, when the communication connection with the destination data terminal device re-originated by the re-call control means is normally terminated, changes the address of the destination data terminal device to the address. 2. The method according to claim 1, wherein the method is stored in a storage unit. 3. The source data terminal device receives an incoming call from the destination data terminal device, and, if the communication connection with the destination data terminal device receiving the call is normally terminated, the destination data terminal device 2. The method according to claim 1, wherein the address of the data terminal device is stored in the storage unit.