JPH10173651A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain communication between plural terminal equipment connected with the same bus of an ISDN line, without being charged by operating communicating by using a set-up message between the two terminal equipment. SOLUTION: A transmitting device at a transmission side writes desired information in a transmission side sub-address and writes invalid telephone number in an incoming side telephone number. Moreover, the transmission side writes the address of the terminal equipment for operating communication in an incoming side sub-address (S301). The transmission side prepares a set-up message and operates calling (S302). At a public line network side, the invalid number is written in the incoming side telephone number, and a line is disconnected (S303). Since set-up message runs on a bus, and the terminal equipment checks whether or not its own address number is present in the incoming side sub-address (S304) an when its own address number is present, the terminal equipment reads information written in the transmission side sub-address (S305).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for performing communication between a plurality of terminal devices connected to the same ISDN line bus.

[0002]

2. Description of the Related Art In an ISDN line, up to eight terminal devices can be connected to the same bus. For example, even when communication is performed between terminal devices in the same house connected to the same bus, a telephone call is made to connect to a public line network and perform communication.

[0003]

However, according to such a method, even when communication is performed between terminal devices connected to the same bus, communication is performed via a public line network, so telephone charges are charged. There was a problem.

[0004] The present invention has been made in view of such a problem, and the object thereof is to provide an IS without charge.
It is an object of the present invention to provide a communication system for performing communication between a plurality of terminal devices connected to the same bus of a DN line.

[0005]

In order to achieve the above object, the present invention provides a communication system for performing communication between a plurality of terminal devices connected to the same bus of an ISDN line.
A communication system is characterized by performing communication using a setup message between two terminal devices.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Embodiments will be described in detail. FIG. 1 is a schematic configuration diagram of a communication system according to one embodiment of the present invention. As shown in FIG. 1, this system includes a home (consumer) 1, an ISDN
.., 7n and a bus 9; and the customer 1 is a DSU 5, a plurality of terminal devices 7a,.
, A bus 9 and a plurality of terminal devices 7a,.
... are connected. Bus 9 is ISDN via DSU5
It is connected to the public line 3.

.., 7n are, for example, personal computers and telephones, and the terminal devices 7a, 7b,.
7b,..., 7n each have a sub-address (for example, “00”).
1 "," 002 ", ...).

FIG. 2 is a format diagram of the setup message 11. The setup message 11 includes a header 13, a caller telephone number 15, and a caller subaddress 1.
7, a callee telephone number 19, a callee subaddress 21 and the like.

The header 13 indicates the beginning of the message, the caller's telephone number 15 contains the telephone number of the caller, and the caller's subaddress 17 normally contains the caller's subaddress. Predetermined information is written. The called party's phone number 19 contains the phone number of the called party,
The sub-address of the called party is entered in the called party sub-address 21.

First, an operation procedure of the communication system according to the first embodiment will be described with reference to a flowchart of FIG. Here, the terminal device 7a and the terminal device 7 in FIG.
The case where communication is performed between b will be described. The calling terminal device (for example, the terminal device 7a) writes desired information to the calling-side sub-address 17 and writes an invalid telephone number (for example, “0”) to the called-side telephone number 19. Further, the transmitting side transmits the address (for example, “00”) of the terminal device (for example, the terminal device 7 b) to communicate with the sub-address 21 of the receiving side.
2 ") is written (step 301).

[0011] After creating the setup message 11, the calling side makes a call (step 302). On the public line network side, the line is disconnected because an invalid number "0" is written in the called telephone number 19 (step 30).
3). Since the setup message 11 is flowing on the bus 9, each terminal device 7a,... Checks whether or not the destination sub-address 21 has its own address number (step 304). If the address number is, for example, the terminal device 7b reads the information written in the calling side sub-address 17 (step 305).

The receiving side determines whether or not to end (step 306). If not, the receiving side becomes the transmitting side and returns to step 301. That is, the calling side and the called side alternately perform communication.

As described above, according to the first embodiment, communication is performed by writing desired information to the subaddress 17 of the setup message 11 flowing on the bus 9. At this time, the terminal device 7 is used without using the ISDN public line 3.
Since information is exchanged between a,..., there is no charge.

Next, an operation procedure of the communication system according to the second embodiment will be described with reference to a flowchart of FIG. Note that the telephone numbers of the terminal devices are the same. The terminal device on the transmitting side (for example, the terminal device 7a) writes desired information to the sub address 17 on the transmitting side and replaces its own telephone number (for example, 123-456) with the telephone number 19 on the receiving side.
Write 7). Further, the calling side writes the subaddress (for example, “002”) of the terminal device with which communication is to be performed to the called side subaddress 21 (step 401).

After creating the setup message 11, the calling side makes a call (step 402), and the public line network connects the line (step 403). When the telephone rings, the receiving side (for example, the terminal device 7b) disconnects the line and reads the information written in the calling side sub-address 17 (step 404). The called side determines whether or not to end (step 405), and if not, the called side is now the calling side and returns to step 401. That is, the calling side and the called side alternately perform communication.

As described above, according to the second embodiment, the calling party actually makes a call, but the called party disconnects the line and reads the information written in the calling party sub-address 17. That is, since the line is once connected and immediately disconnected, information can be exchanged without being charged.

In each of the above-described embodiments, communication is performed between a plurality of terminal devices connected to the same bus in the same customer. The present invention can also be used inside or the like.

[0018]

As described above in detail, according to the present invention, it is possible to provide a communication system for performing communication between a plurality of terminal devices connected to the same bus of an ISDN line without being charged.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a communication system according to an embodiment of the present invention;

FIG. 2 is a format diagram of a setup message 11;

FIG. 3 is a flowchart showing an operation procedure of the communication system according to the first embodiment;

FIG. 4 is a flowchart showing an operation procedure of the communication system according to the second embodiment;

[Explanation of symbols]

 1 Consumer 3 ISDN public line 5 DSU 7 Terminal 9 Bus 11 Setup message 13 Header 15 Caller phone number 17 …… Caller subaddress 19 ……… Callee phone number 21 ……… Callee subaddress

Claims (4)

[Claims] 1. A communication system for communicating between a plurality of terminal devices connected to the same bus of an ISDN line, wherein communication is performed between two terminal devices using a setup message. 2. A communication system for communicating between a plurality of terminal devices connected to the same bus of an ISDN line, wherein a terminal device on a calling side writes predetermined information in a caller subaddress in a setup message, and Write an invalid number in the telephone number, write the address of the other terminal device in the called party subaddress, make a call, and when the call is made, the public line network disconnects the line and the called terminal device Is a communication system that reads information written in the sender sub-address if the recipient sub-address has its own address number, and performs communication by alternately switching the calling side and the called side. 3. A communication system for performing communication between a plurality of terminal devices having the same telephone number connected to the same bus of an ISDN line, wherein the terminal device on the calling side has a predetermined caller subaddress in the setup message. Write information, write your own phone number in the called party's telephone number, write the address of the other party's terminal device in the called party's subaddress, make a call, connect the PSTN to the line, Is a communication system that disconnects the line when a call is made, reads the information written in the caller's subaddress, and performs communication by alternately switching the calling side and the called side. 4. The communication system according to claim 1, wherein the same bus is located in a house.