JPH0779300A - Isdn terminal adapter - Google Patents

Abstract

PURPOSE:To obtain an ISDN terminal adapter capable of responding to a new incoming call even when an ISDN line is in use, regarding the ISDN terminal, adapter used in an ISDN communication. CONSTITUTION:In an ISDN terminal adapter 100 composed of a processor 10 controlling a communication processing, a line control part 21 connected with an ISDN line L1 and terminal control parts 31 to 3n taking the interface with terminals T1 to Tn, a line control part 22 connected with a detour line L2 is provided. When the processor 10 detects that both two information channels are in communication, one of the calls in communication with an LSDN line L1 is reconnected with the detour line L2 and a new incoming call is responded by making one information channel vacant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN terminal adapter used for communication of an ISDN basic interface.

ISDN (Integrated Services Digital
Network) is characterized by being able to provide a wide range of services, including telephone and non-telephone systems, on the same network. For that purpose, the user-network interface is ISDN.
ISDN, which is defined by the interface recommendation
It may be necessary to connect a terminal device that does not conform to the interface recommendation to the ISDN network.

In such a case, the interface of the terminal device that does not conform to the ISDN interface recommendation is IS
A DN terminal adapter is used to convert to an ISDN standard interface and connect to an ISDN network for communication.

The basic interface of ISDN is 64k.
2 bps information channels (B1, B2 channels) and 1
It is composed of a signal channel of 6 kbps (D channel), and it is possible to perform two-channel communication with one line.

In such an ISDN terminal adapter used for communication using an ISDN line, by accommodating a bypass line, an ISDN terminal capable of responding to a call received during communication by the ISDN line. Adapter required.

[0006]

2. Description of the Related Art FIG. 9 is a block diagram for explaining a conventional example. In the figure, 100 is an ISDN terminal adapter, 10 is a processing unit, 21 is a line control unit, 31 to 3n are terminal control units, 30a is a codec, 41 is a random access memory (hereinafter referred to as RAM), and 42 is a read only. A memory (hereinafter referred to as a ROM) and T1 to Tn are terminals.

The line control unit 21 is connected to the ISDN line L1, and the processing unit 10 connects the line according to the program written in the ROM 42 and writes the data necessary for the processing in the RAM 41. .

The ISDN line L1 can perform two-channel communication with one line, separates the information channels B1 and B2 from each other, and connects the terminals T1 to Tn via the terminal control units 31 to 3n. It connects to either and communicates.

Further, a codec 30a is provided in the terminal control unit 30n, and the digital signal sent from the ISDN line L1 is converted into an analog signal by the codec 30a, input to the terminal Ti, and output from the terminal Ti. The analog signal is converted into a digital signal by the codec 30a and output to the ISDN line L1. The codec 30a is used when the terminal Ti is an analog terminal such as a telephone and is not necessary when the terminal Ti is a digital terminal.

[0010]

FIG. 10 shows a sequence diagram of a conventional example. FIG. 10 shows the ISDN adapter 10 of FIG.
When performing a two-channel communication using 0, a sequence is shown in which when a new incoming call is received, a busy tone BT indicating that the caller is in communication is transmitted.

Therefore, it is necessary for the caller to listen to the busy tone BT and redial the call after a certain period of time elapses. When the caller wants to make an emergency communication, he / she may not be connected to the caller.

[0012] As a service on the network side, there is an incoming call notification service during communication, but of course there is a charge for using this service. Furthermore, using this service,
Even if the user is notified that there is an incoming call during communication, it is necessary to hold or disconnect the call currently in communication and then answer the incoming call.

The present invention seeks to provide an ISDN terminal adapter capable of answering a new incoming call even when the ISDN line is in use.

[0014]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 100 is an ISDN terminal adapter used for ISDN communication, 10 is a processing device for controlling communication processing, 21 is a line control unit connected to the ISDN line L1, and 31 to 3n are terminals T1 to T1.
It is a terminal control unit that interfaces with Tn.

Further, 22 is provided according to the present invention,
This is a line control unit connected to the bypass line L2, and when the processing device 10 detects that the two information channels of the ISDN line basic interface are both communicating,
One of the calls communicating on the ISDN line L1 is switched to the detour line L2, and a new incoming call is answered.

[0016]

With the ISDN basic interface, it is possible to perform two-channel communication with one line. I
The terminals T1 to Tn that do not have the SDN standard interface are converted to the standard interface by the ISDN terminal adapter 100 and are connected to the ISDN line L1.

Such an ISDN terminal adapter 1
00, the line control unit 22 connected to the detour line L2 is provided, and when the two information channels of the ISDN line L1 are both in use, the line control unit 22 controls communication of one information channel during communication. By switching and connecting to the detour line L2, it is possible to respond to a new incoming call from the ISDN line L1 while leaving one information channel for communication by the ISDN line L1 free.

[0018]

FIG. 2 is a block diagram illustrating an embodiment of the present invention. In the figure, 100 is an ISDN terminal adapter, 10 is a processing unit, 21 and 22 are line control units, 31
3n is a terminal control unit, 30a is a codec, 41 is a RAM that also serves as a command registration memory, 42 is a ROM, and T1.
~ Tn is a terminal.

The line control unit 21 is connected to the ISDN line L1, and the processing unit 10 connects the line according to the program written in the ROM 42 and writes the data necessary for the process in the RAM 41. .

The ISDN line L1 can perform two-channel communication with one line, separates the information channels B1 and B2 from each other, and connects the terminals T1 to Tn via the terminal control units 31 to 3n. It connects to either and communicates.

With the above configuration, the switching command is registered in the RAM 41. Here, one of the ISDN lines L1 is used for data transmission, the other one is used for transmission of a voice signal, two information channels are in communication, and further, the data transmission from the ISDN line L1 is performed. When an incoming call is predicted, a request for issuing a line switching command for switching the information channel used for the transmission of the voice signal to the bypass line L2 is transmitted from any of the terminals T1 to Tn, and this request is received. The processing device 10 sends the line switching command in the RAM 41 to the read line control units 21 and 22, switches one information channel of the ISDN line L1 used to the detour line L2, and leaves the information channel free. Thus, a new incoming call can be answered from the ISDN line L1. At this time, disconnection of one information channel of the ISDN line L1 is performed by the line control unit 21.
And the application of the terminal Ti.

In this configuration, when a dedicated line is used for the detour line L2, the request for issuing a line switching command from the terminals T1 to Tn is issued by the terminal adapters 100 on both sides of the communication.

When a public line is used as the detour line L2, for a frequently used terminal, the telephone number being used for communication is registered in the RAM 41, and a switching command is issued to switch the line. After that, it is possible to automatically dial and connect. In this case,
As a matter of course, one terminal is the calling side and the other is the called side.

In the present embodiment, the line switching command is assumed to be registered in the RAM 41 as a command registration memory, but it is also possible to register it in the ROM 42. Further, the command is not registered as a command and the terminal is not registered. T
It is also possible to directly issue from 1 to Tn.

FIG. 3 is a flow chart of the embodiment of the present invention. The operation of the embodiment of the present invention shown in FIG. 2 will be described with reference to this flowchart. The ISDN terminal adapter 100 receives data from a terminal Ti (any one of the terminals T1 to Tn is Ti).

It is determined whether the received data is a request for issuing a line switching command, and if not, the process proceeds to. When the received data is a request for issuing a line switching command, the processing device 10 reads the line switching command in the RAM 41, and the line control units 21, 2
2 is controlled to connect one information channel of the ISDN line L1 to the bypass line L2.

It is determined whether the detour line L2 is a dedicated line, and if not, the process proceeds to. Since the detour line L2 is a dedicated line, communication is started in that state. If the result of the judgment is not a leased line, dialing is performed and connection processing is performed.

Since the result of the judgment in step 6 is not a request to issue a line switching command, that is, normal communication data, it is sent to the line as it is. FIG. 4 is a block diagram for explaining another embodiment (1) of the present invention. In the configuration shown in the figure, a line switching notifying section 50 is provided in the configuration of the embodiment shown in FIG.

In the configuration shown in FIG.
A line switching command is registered in 1. Where I
When the two information channels of the SDN line L1 are both in communication, the terminal Ti sends a request for issuing a line switching command, and the processing device 10 receiving this request sends R
The line switching command in the AM 41 is read out and sent to the line control units 21 and 22, one channel of the ISDN line L1 being used is switched to the detour line L2, and the channel is vacant so that the ISDN line L1 You can answer new incoming calls.

At this time, at the same time, the line switching notifying section 50 sends an ISD to the ISDN terminal adapter 101 of the other party.
Notification is made using the "user-user" information of the SETUP information, which is the N protocol. The ISDN terminal adapter 101 of the other party receiving this information determines that the line switching is requested, and the line control units 21 and 22 switch the line.

FIG. 5 is a sequence diagram of another embodiment (1) of the present invention. In the figure, when the terminal T01 accommodated in the ISDN terminal adapter (indicated by TA in the figure) 100 and the terminal T11 accommodated in the partner ISDN terminal adapter 101 are communicating, the terminal T01 issues a line switching request. Here is an example.

When the ISDN terminal adapter 100 receives the request to issue the line switching command from the terminal T01, the line control units 21 and 22 switch the line and S
The "user user" information of the ETUP information is used to notify the ISDN terminal adapter 101 of the other party. Upon receiving this information, the ISDN terminal adapter 101 of the other party judges that the line switching is requested, and the line control units 21 and 22 switch the line.

FIG. 6 shows a sequence diagram of another embodiment (2) of the present invention. The figure shows an operation sequence of the line switching notifying unit 50 in the configuration of FIG. 4, which is configured by the command issuing unit 60 which issues a switching command to the ISDN terminal adapter 101 of the other party through the information channel.

When the request issuance of the line switching command is received from the terminal T01, the lines are switched by the line control units 21 and 22, and the command issuing unit 60 sends the line switching command (shown as a switching command in the figure) to the other party through the information channel. Is issued to the ISDN terminal adapter 101, and the line control units 21 and 22 switch the line.

FIG. 7 shows a sequence diagram of another embodiment (3) of the present invention. In the figure, in the configuration of FIG. 4, the line switching notifying unit 50 is used to set the incoming signal SET from the ISDN line L1.
When UP is detected, the line switching is performed, and the operation sequence of the line switching processing unit 70 which sends the line switching command to the ISDN terminal adapter 101 of the other party is shown.

When the line switching processing unit 70 detects the incoming signal SETUP from the network, the line control units 21 and 22 switch the line, and then the line switching processing unit 70 sends a switching command to the ISDN terminal adapter 101 of the other party through the information channel. Is issued and the lines are switched by the line control units 21 and 22.

FIG. 8 shows a flowchart of another embodiment (4) of the present invention. In the figure, the configuration of FIG. 4 is provided with a priority setting unit 80 for setting the priority for each port. In FIG. 8, the priority setting unit 80 has priority P1> P.
In this example, 2> P3 is set. The operation will be described below with reference to the flowchart.

It is assumed that the ISDN line L1 is currently used for two-channel communication at the ports P2 and P3. Here, an incoming call is received from the network at port P1.

It is determined whether the port has a higher priority than the port being used, and if not, the process proceeds to. If the port has a higher priority than the port in use, the port with the lowest priority, here, port P3
Disconnect.

By disconnecting the port P3 having the lowest priority, a new incoming call becomes possible.
A call is made to the port P1 having the highest priority. It ends after performing data communication.

There is no port with a higher priority than the port in use, that is, the port in use has a higher priority and does not respond to a new incoming call, so the incoming call is disconnected and the process ends.

[0042]

According to the present invention, the ISDN terminal adapter is provided with a line control unit for connecting to a bypass line, and when two information channels are in communication with each other, switching to the bypass line enables a new incoming call. Can respond to.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a block diagram illustrating an embodiment of the present invention.

FIG. 3 is a flowchart of an embodiment of the present invention.

FIG. 4 is a block diagram illustrating another embodiment (1) of the present invention.

FIG. 5 is a sequence diagram of another embodiment (1) of the present invention.

FIG. 6 is a sequence diagram of another embodiment (2) of the present invention.

FIG. 7 is a sequence diagram of another embodiment (3) of the present invention.

FIG. 8 is a flowchart of another embodiment (4) of the present invention.

FIG. 9 is a block diagram illustrating a conventional example.

FIG. 10 is a sequence diagram of a conventional example.

[Explanation of symbols]

 100, 101 ISDN terminal adapter 10 processing device 21, 22 line control unit 31-3n terminal control unit 30a codec 41 RAM 42 ROM 50 line switching notification unit 60 command issuing unit 70 line switching processing unit 80 priority setting unit T1 to Tn, T01, T11 Terminal L1 ISDN line L2 Detour line

Claims (6)

[Claims] 1. An ISDN terminal adapter (100) used for communication of an ISDN basic interface, comprising a processing device (10) for controlling communication processing and a line control unit (21) connected to an ISDN line (L1).
And an ISDN terminal adapter (100) comprising terminal control units (31 to 3n) for interfacing with terminals (T1 to Tn), a line control unit (22) connected to a bypass line (L2) is provided, Two information channels (B of ISDN line (L1)
When the processing device (10) detects that both the communication device 1 and the communication device B2 are in communication, the ISDN line (L)
One of the calls communicating in 1) is used as the detour line (L2)
ISDN terminal adapter characterized by connecting to the 2. The ISDN terminal adapter (100) according to the preceding paragraph, further comprising a command registration memory for registering a line switching command, wherein one of the terminals (T1 to Tn) is connected to the processing device (1).
0), the processor (10) which has transmitted the request for issuing the line switching command in the command registration memory and which has received the line switching command is controlled by the line control unit (21, 22). 2. The ISDN terminal adapter according to claim 1, wherein one of calls communicating on the line (L1) is reconnected to the detour line (L2). 3. The ISDN terminal adapter (100) according to claim 1, wherein the processing device (1) receives an issue request for a line switching command issued from one of the terminals (T1 to Tn).
0) is the ISDN terminal adapter (10
1) A line switching notifying section (50) for transmitting "call setting information" of information requesting line switching is provided, and one of the terminals (T1 to Tn) accommodated in the ISDN terminal adapter (100) is provided. From the processing device (1) which has sent a request to issue a line switching command from the command registration memory and has received the line switching command.
0) is the line control unit (21, 22) for the IS
One call communicating on the DN line (L1) is switched to the detour line (L2), and the line switching notifying unit (50) passes through a signal channel to the ISDN terminal adapter (101) of the other party. ), The ISDN terminal adapter (101) of the other party receiving the "call setting information" judges that it is a line switching instruction, and the line control unit (21, 22).
The ISDN terminal adapter according to claim 1, wherein one call currently being made on the ISDN line (L1) is reconnected to the detour line (L2). 4. The ISDN terminal adapter (100) according to claim 1, wherein when the processing device (10) receives a request to issue a line switching command issued from one of the terminals (T1 to Tn), Partner ISDN terminal adapter (10
A command issuing unit (60) for issuing a line switching command is provided in 1), and a line switching request is transmitted from one of the terminals (T1 to Tn) accommodated in the ISDN terminal adapter (100), and the line switching request is issued. Receiving the processing device (1
0) is the line control unit (21, 22) for the IS
One of the calls communicating on the DN line (L1) is switched to the detour line (L2), and the command issuing unit (60) sends an information channel to the ISDN terminal adapter (101) of the other party. Through the line switching command, and the other party's ISDN terminal adapter (101) receiving the line switching command determines that the line switching command is received, and the line control unit (21, 2).
2. The ISDN terminal adapter according to claim 1, wherein one of the calls made on the ISDN line (L1) is reconnected to the detour line (L2) according to 2). 5. The ISDN terminal adapter (100) according to claim 1, when a "call setting signal" from the ISDN line (L1) is detected during communication, a call is currently made on the ISDN line (L1). A line switching processing unit (70) for connecting the existing call to the detour line (L2) is provided, and when the processing device (10) detects a "call setting signal" from the ISDN line (L1), the line control is performed. Department (2
1, 22), one of the calls on the ISDN line (L1) is switched to the detour line (L2),
The ISDN terminal adapter according to claim 1, wherein the ISDN terminal adapter responds to a new incoming call. 6. The ISDN terminal adapter (100) according to claim 1, wherein the ISDN line (L1) and the detour line (L2).
A priority setting section (80) for setting the priority order of the ports is provided, the priority order of the ports is set by the priority setting section (80), and when a call is received on the line currently in use,
The processing device (10) judges the priority of each port, and if the priority of the incoming port is higher than the port currently in use, disconnects the port with the lowest priority and assigns to that port. The ISDN terminal adapter according to claim 1, wherein the ISDN terminal adapter is used to receive an incoming call.