Line controller

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a line control device including a control unit that uses the control channel of an ISDN line as an information channel.

【0002】

[Previous technology]

Recently, ISDN (Integrated Services Digital Network) services, which enable one subscriber line to secure two data channels (B channel) and one signal channel (D channel), have become widespread, and telephones and computers have become widespread. It has come to be used for communication and G4 facsimile communication.

【0003】

However, in the conventional ISDN line, two B channels are used together, and at least one of them is using communication that can use packet switching of D channel, and when there is a new incoming call, D Even though the channel is free, there is no line control device that transfers the communication that can use the packet switching of the above D channel to the D channel and transfers the B channel to the communication by a new incoming call, and there is no ISDN line. I couldn't take advantage of it well.

【0004】

[Problems to be Solved by the Invention]

The present invention has been proposed in view of the above circumstances, and when a new incoming call is made while the ISDN line is used for two B-channel co-communication, one of the above two communications is used. It is an object of the present invention to provide a line control device equipped with a control unit that transfers one to the D channel and transfers the B channel to new communication.

【0005】

[Means for solving problems]

The present invention proposed to achieve the above object is a state in which two B channels are full and at least one of them is used by communication capable of using D channel packet switching in an ISDN line. Then, when there is a new incoming call, the communication that can use the packet switching of the D channel is switched to the packet switching of the D channel, and the configuration is provided with a control unit that uses the B channel for the incoming communication. It has become.

【0006】

[Action]

According to the line control device of the present invention, in an ISDN line, two B channels can be used for co-communication and there is no space, and at least one of them can use packet switching of a D channel other than a telephone. When a new call is made while the available communication is in use, the above-mentioned D-channel packet switching is switched to the above-mentioned D-channel packet switching, and the above-mentioned new arrival is made. Since the B channel is used for the called communication, all three channels of the ISDN line can be effectively used.

【0007】

[Example]

An embodiment of the present invention will be described below. FIG. 1 is a diagram showing an example of an ISDN network for explaining the line control device according to the present invention. The line control device of the present invention will be described with reference to FIG.

【0008】

At the time of making a call, each terminal is input with a priority according to the importance of the communication. The input priority is stored on the calling side, and is also sent to the called side and stored on the SETUP (call setting request) message of the protocol. When two B channels B1 and B2 are used for facsimile FAX1 and telephone TEL1 respectively on ISDN line 10 at point d and there is no space, and a new call is received from facsimile FAX4 at point c (Fig. 1 (Fig. 1 (Fig. 1)). A)), Compare the priority of facsimile communication of facsimile FAX1 that can communicate using this communication and packet switching of D channel. As a result, if the communication from the facsimile fax 4 at point c has a higher priority, the facsimile communication of the facsimile fax 1 that can communicate using the packet switching of the D channel is switched to the packet switching of the D channel, and the above Use channel B for communication from facsimile FAX 4 at point c (Fig. 1 (B)).

【0009】

To describe the above operation in more detail, in the ISDN line 10 at point d, two B channels B1 and B2 are used for facsimile fax 1 and telephone TEL 1, respectively, and there is no space, and the priority is given from facsimile fax 4 at point c. When set and there is an incoming call to point d via the D channel (Fig. 1 (A)), each terminal at point d reads the SETUP (call setting request) 1 message of this protocol and is not communicating. An ALERT (Alerting: ringing notification from the called terminal) 1 message is returned from the facsimile fax 2 to the facsimile fax 4 at point c via the D channel. However, since channel B is not available, channel B is not connected and incoming calls cannot be made. In such a state, the facsimile FAX1 capable of communicating using the packet switching of the D channel at point d compares its own communication priority with the priority contained in the above SETUP1 message, and self. If the priority of is high, communication is continued as it is. If its own priority is low, the communication is interrupted and a DISC (Disconnect: call release request) message is sent to the facsimile fax machine at point b via the D channel, thereby disconnecting the B channel and calling the facsimile fax 3 side. The number is released, and a REL (Release: channel disconnection completion notification and call number release request) message is returned. When the facsimile FAX1 receives the REL message, the call number on the facsimile FAX1 side is also released, and REL COM (Release Complete: channel release and call number release completion notification) is sent to the facsimile FAX3, and the call on the B channel is completed.

【0010】

The facsimile FAX1 then sends a packet-switched SETUP2 message of the D channel to the facsimile FAX3 via the D channel. In response to this, the facsimile fax 3 first returns a CALL PROC (Call Proceeding: notification during call setting processing) message, and when the call is started, the ALERT (Alerting: notification during call from the called terminal) 2 message is sent by facsimile FAX 1. Send to. When the facsimile FAX3 answers the above call, it sends a CONN (Connect: answer notification of the called terminal) message to the facsimile FAX1, the packet switching channel of the D channel is connected, and the above interrupted communication shifts to the packet switching. Will be restarted.

【0011】

On the other hand, when the above call on channel B (FAX3 FAX1) is completed, the facsimile FAX2 at point d responds to the call from the facsimile FAX4 at point c and sends a CONN message to the facsimile FAX4, and the above empty space. The new B1 channel is connected and communication (FAX4 FAX2) via the new B1 channel starts (Fig. 1 (B)).

【0012】

When the above new B1 channel data transmission (FAX4 FAX2) is completed, a DISC (Disconnect: call release request) message is sent from the facsimile FAX4 to the facsimile FAX2 via the D channel, which causes the B1 channel to be disconnected. The call number on the facsimile FAX2 side is released, and a REL (Release: channel disconnection completion notification and call number release request) message is returned. When the facsimile FAX4 receives the REL message, it also releases the call number on the facsimile FAX4 side, sends a REL COM (Release Complete: channel release and call number release completion notification) message to the facsimile FAX2, and the call (FAX4 FAX2) is completed. To do. 20 to 30 in FIG. 2 are flow charts showing a series of operations from the priority set of the facsimile fax 4 to the end of communication.

【0013】

By the way, if the data transmission (FAX4 FAX2) by the above new B1 channel continues at the time when the communication (FAX3 FAX1) resumed after moving to the packet exchange is completed, the same as the above call completion procedure. , Send and receive DISC message, REL message and REL COM message between facsimile FAX3 and facsimile FAX1 to complete the call (FAX3 FAX1).

【0014】

On the contrary, while the communication (FAX3 FAX1) resumed after moving to packet switching, the above new B1 channel call (FAX4 FAX2) is completed, the B2 channel call is completed, etc. Then, when the B channel becomes free, the above packet-switched communication (FAX3 FAX1) interrupts the communication, and the same as above (however, the transmission and reception are reversed) between the facsimile FAX3 and the facsimile FAX1. Send and receive DISC messages, REL messages, and REL COM messages between them, and once complete the call (FAX3 FAX1). Then, the facsimile FAX 1 sends the B channel SETUP (call setting request) 3 message to the facsimile FAX 3 via the D channel. In response to this, the facsimile FAX3 first returns a CALL PROC (Call Proceeding: notification during call setting processing) message, and when the call is started, the ALERT (Alerting: call notification from the called terminal) 3 message is sent by facsimile FAX1. Send to. Then, when the facsimile FAX3 answers the above call, CONN (Connect) : Response notification of the called terminal) A message is sent to the facsimile FAX1, the vacant B channel is connected, and the above-mentioned interrupted communication (FAX3 FAX1) returns to the B channel and resumes. 31 to 64 in FIG. 3 are flow charts showing a series of operations of such a facsimile FAX1.

【0015】

In the above embodiment, when there is a new incoming call (Fig. 1 (A)), the priority of this communication and the facsimile communication during communication is compared, and the new communication has the higher priority. If is high, the facsimile communication during communication is switched to D channel packet switching and B channel is used for new communication (Fig. 1 (B)), but on the contrary, new communication If the priority is low and communication is possible using D-channel packet switching, new communication may be switched from B-channel to D-channel packet switching to start communication. In this case, if the B channel becomes free, the packet switching of the D channel is switched to the free B channel.

【0016】

[Effect of the invention]

According to the line control device of the present invention, in an ISDN line (B channel × 2 + D channel × 1), two B channels are used for co-communication and there is no space, and at least one of them is other than a telephone. When a new call is made while communication that can use D-channel packet switching is in use, the above-mentioned D-channel packet switching can be used for D-channel communication. By switching to packet switching and using channel B for the above newly called communication, all three channels of the ISDN line can be effectively used, and the transmission efficiency of data per unit time can be improved. Increase.

[Simple explanation of drawings]

[Figure 1]

(A) and (B) are diagrams showing an example of an ISDN network for explaining the line control device according to the present invention.

[Figure 2]

It is a flow chart which showed a series of operations from the priority set of the facsimile FAX4 to the end of communication.

[Fig. 3]

It is a flow chart which showed the series operation of the facsimile FAX1.

[Explanation of symbols]

10 ISDN line B1, B2 B channel D D channel