JP2918411B2 - Terminal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network terminal device. In particular, the present invention relates to a network terminal device that can easily determine whether or not there is a currently available line.

[0002]

2. Description of the Related Art In recent years, various communication network systems have been developed with the progress of communication technology and diversification of communication modes. One of such communication network systems is an integrated services digital network (ISDN, Integra).
rated Service Digital Netw
ork). This ISDN is to provide various communication processing services such as telephone, data communication and facsimile communication by integrating with one digital communication network.

In recent years, research and development of ISDN-compatible communication devices have been actively conducted, and so-called private systems including not only communication terminal devices but also private branch exchanges (PBXs) have been adapted to ISDN. There is also an active movement to realize integrated voice and data services.

For example, in the basic interface of ISDN, two B channels, which are circuit switching channels, and a D channel, which is one packet switching channel, are time-division multiplexed and provided by one communication line. I have. In the so-called primary interface, 23 B channels and 1 D channel are provided. As described above, since a plurality of lines are provided at one time in the ISDN, it is possible to construct a private system using the PBX. That is, one IS
It has been proposed to connect a plurality of communication terminals to a DN communication line and share the plurality of lines with the plurality of communication terminals. With this configuration, it is possible to save ISDN communication lines and to effectively use the lines.

FIG. 3 shows a system configuration diagram of such an ISDN indoor system. In FIG. 3, PB
A plurality of ISDN terminals 12a to 12h are connected to X10. As shown in FIG. 3, two B channels (B1, B2) and a D channel are provided from the PBX 10 in a so-called bus shape, and each ISDN terminal 12
a to 12h are respectively connected to the bus so as to hang. Further, each of the ISDN terminals 12a to 12h is provided with a display unit 13 so that various information can be displayed.

FIG. 4 shows an ISD as shown in FIG.
It is a sequence diagram which shows an example of operation | movement of an N premises system. First, the user of the ISDN terminal 12a goes off-hook on the ISDN terminal 12a and dials the telephone number of the other party. When this dialing operation is completed, the ISDN terminal 12a sends a "call setting" S1 as a call message to the PBX 10. If the PBX 10 determines that there is no free space in the circuit switching channel (B channel), it sends a response message “release complete (reason display: no available channel)” S2 to the ISDN terminal 12a. here,
"Reason display" in "release complete (reason display: no available channel)" is the name of the parameter, and "no available channel" is the display of the value of the parameter. I
Upon receiving the "release completed" S2, the SDN terminal 12a recognizes that there is no vacancy in the circuit switching channel (B channel) and displays a so-called "all busy" on the display unit 13. By this display, the user has recognized that the circuit-switched channel (B channel) is full, that is, that the user is busy.

[0007]

In the conventional ISDN local area system, the user of each ISDN terminal 12 (a to h) determines whether or not there is a vacancy in the circuit switching channel only after dialing. Can be. Therefore,
Conventionally, there has been a problem that it is difficult to know the availability of the circuit-switched channel before dialing.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide an ISDN terminal capable of automatically knowing the availability of a circuit-switched channel.

[0009]

According to a first aspect of the present invention, there is provided an apparatus for connecting to a plurality of circuit-switched channels to solve the above-mentioned problems.
A switch that is, when receiving the paging message of unused numbers from the terminal device, when the circuit-switched channel <br/> are used all the contents to the effect that the circuit switched channel is being used all Before the first response message
Serial returned to the terminal device, the exchange when there is a vacancy in the circuit-switched channel to return the second response message content indicating that the no unused numbers are used in the terminal device,
In the terminal apparatus connected to the return, with respect to the exchange, a paging message sending means for sending the unused number of call messages predetermined for each predetermined period, from the exchange in response to the paging message Received response message is received, if the response message is the first response message
Determining that the circuit switched channel is being used all to include a line status determination means determines that the idle is present in the circuit-switched channel if said response message is the second response message Features.

[0010] The second aspect of the present invention, in order to solve the above problems, in the end terminal device that put the first aspect of the present invention, display means for displaying the status of the a determination result of the channel state determining means line It is characterized by including.

[0011] The third aspect of the present invention, in order to solve the problems described above, an end terminal device that put the first or second aspect of the present invention, the line status determination means does not receive said response message status in, when said call message sending means from sending predetermined a call message wait time has elapsed, the line status determination means, circuit switching
It is characterized in that it is determined that a failure has occurred in the channel .

[0012]

According to the first aspect of the present invention, the call message transmitting means transmits a call message of an unused number to the exchange at predetermined intervals even if the operator does not dial. Therefore, a call message can be sent to the exchange without dialing by the operator, and as a result, a response message can be received from the exchange. Thus, by the contents of the received response message is line status determination means for identifying, circuit switching Ji
It is possible to determine whether there is a free space in the channel .

[0013] display means in the second of the present invention displays the availability of the line is determined in the first aspect of the present invention. Therefore, the operator can easily know from the display whether or not there is a free line.

In the third aspect of the present invention, if a response message from the exchange is not received even after the elapse of a predetermined waiting time, it is determined that a failure has occurred in the circuit-switched channel . Therefore, it is possible to automatically detect a failure on the circuit switching channel .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

[0016] An I to which the ISDN terminal according to the present embodiment is applied.
The configuration block diagram of the SDN indoor system is the same as the conventional configuration block diagram described above, that is, the configuration block diagram shown in FIG. The characteristic of the ISDN terminals 12a to 12h in the present embodiment is that the ISDN terminals 12a to 12h automatically check whether or not there is a free channel, so that the display unit 13 displays the circuit switching channels 15a and 15b. It is to display the availability. Thus, according to the present embodiment, the operator can recognize the use status of the circuit switching channels 15a and 15b by looking at the display unit 13 without dialing.

The operation of this embodiment will be described with reference to FIGS. FIG. 1 is a sequence diagram illustrating a flow of checking whether there is an empty channel according to the present embodiment.
FIG. 1 shows only the operation of the ISDN terminal 12a and the PBX 10, but other ISDN terminals 12b to 12b
h performs the same operation as that of the ISDN terminal 12a. FIG. 2 is a flowchart showing the operation of the ISDN terminals 12a to 12h.

First, the ISDN terminal 12a starts the timer 1 as shown in step 101 of FIG. This timer 1 uses the PBX for the ISDN terminal 12a.
This is a timer that determines the period for transmitting the special-number call setting to the PBX 10. When the timer 1 times out, the ISDN terminal 12a transmits the special-number call setting to the PBX 10.

After starting timer 1, step 1
At 02, the ISDN terminal 12a shifts to a waiting state. In this state, when any event occurs, for example, when a call message is received or when an operator sends a call message, reception / transmission processing is performed in accordance with each of the generated events. However, if the timer 1 times out without any event occurring in step 102, the control moves to step 103.

In step 103, the call setting (special number), which is a call message based on the special number, is sent to PBX1.
Sent for 0. Here, the special number is an unused telephone number.

That is, the ISDN terminal 12a in the present embodiment sends out a call message to an unused telephone number at the cycle of the timer 1. This message, “call setting (special number)”, corresponds to message S1 in FIG.
0, S13, and S15. By transmitting this message, as will be described later, if a message indicating that it is an unused number is returned from the PBX 10, it is determined that there is a free channel. If a message indicating that there is no free channel is returned, the channel is returned. Are all used. PBX in the present embodiment The ISDN terminal 12a in the present embodiment calls an unused telephone number at the cycle of the timer 1. This call setting (special number) corresponds to message S10 or S10 in FIG.
13, S15. By transmitting this message, the PBX 10 receives the call message with the unused number, and if there is no available line, the parameter "reason display" having a value of "no available channel".
The response message containing the is returned. Such a PBX 10 is well known as described in the prior art.

In step 104, the timer 2 is started. The timer 2 is a timer having a cycle of a maximum time for waiting for a response message from the PBX 10.
If the timer 2 times out without returning a message from the PBX 10 as described later,
The SDN terminal 12a considers that a failure has occurred in the PBX 10 or the network.

After the timer 2 is started in the above step 104, the process returns to the event waiting state in step 105. Then, as shown in FIG. 1, when the message of the completion of release (reason display: no available channel) is returned from the PBX 10, the process proceeds to step 106 as shown in the flowchart of FIG. I do. Here, "reason display" in the release completion message is the type of parameter. “No available channel” is the value of this parameter. The ISDN terminal 12a according to the present embodiment can confirm that all the channels are used and there are no available channels by confirming the value of “no available channel”.

In step 105, the PBX 10
When the message of completion of release (reason display: missing number) is returned, the process proceeds to step 106 as shown in the flowchart of FIG. In this case, as described later, the value of the parameter “reason display” is “missing number”.
Therefore, it is determined that there is an empty channel.

If it is determined in step 105 that the timer 2 has timed out, it is determined that a failure has occurred in the line, and the process proceeds to step 107 described later.

In step 106, the timer 2 is stopped. Then, the process shifts to steps 108 and 109, respectively, for the reason that the control shifts to step 106.
For example, if a message of "release completed (reason display: no available channel)" is returned from the PBX 10, there is no available channel, and so-called all busy display is displayed on the ISDN terminal 12a. In order to indicate to the unit 13, the process proceeds to step 109 described later.

Also, as in S14 shown in FIG. 1, "release complete (reason display: missing number)" from the PBX 10.
Is returned, there are channels available, so if you see a busy signal,
You must cancel this display. Then, in order to cancel this display, the process proceeds to step 108 described later.

In step 107, the display unit 13 displays that a fault has occurred on the line, so that the operator can know that the fault has occurred. This step is a step executed when the timer 2 times out, as described above. That is, as in the case of the message S15 shown in FIG. 1, this step is executed when a predetermined waiting time elapses after the message S15 is transmitted and the timer 2 times out. This step 107
After the above processing, the control moves to the step 103, and a call message of "call setting (special number)" is sent, for example, as shown by the message S16 in FIG.

In step 108, the display indicating that all the lines are busy is released from the display unit 13. This step 10
8, "release complete (Cause: missing number)" from PBX10 as described above is a step that a response message that is executed when <br/> that have been returned. ISDN terminal 12a
By confirming that the value of the "reason display" parameter is "missing number", it is possible to know that there is a free line. What is characteristic in the present embodiment is that it is determined whether or not the line is in a so-called all-busy state based on the content of the message returned from the PBX 10 as described above.

In step 108, the result of this determination is displayed on the display unit 13. Therefore, according to the present embodiment, the operator can know the availability of the line before making a call. This step 108
Is completed, the control moves to step 101 described above.

In step 109, a display indicating that all the lines are busy is displayed on the display unit 13. This step 109
Is a message "release complete (reason indication:
Is executed when "No available channel" is returned. This message is the message S12 "release complete (reason display: no available channel)" shown in FIG.
And this message is returned,
The SDN terminal 12a performs an all-busy display on the display unit 13.
After the process of step 109 is completed, the control shifts to step 101 described above.

As described above, a characteristic of this embodiment is that a call setup (special number), which is a call message based on a special number, is transmitted to the PBX 10 at predetermined intervals.
As a result, "release complete" which is a response message from the PBX 10 can be received at predetermined intervals, and it is possible to determine the line use status based on the content of the message.

In the present embodiment, the ISDN terminals 12 (a to
h), when the conventional general PBX 10 has no available line, even if it receives a call message with an unused number, a message including a parameter "reason indication" having a value of "no available channel" is transmitted. By using the return, an unused number “special number” is transmitted at regular intervals. Thus, the use status of the line can be known at regular intervals.

Further, the ISDN terminal 1 in this embodiment
2 (a to h) is a display unit 13 for displaying a line use status.
, The operator can always be informed of the line usage status.

As a result, according to the present embodiment, it is possible to know the status of use of the line without performing dialing.
This has the effect that an SDN terminal device can be obtained.

Note that the ISDN terminal in this embodiment is:
Since the call message is transmitted at regular intervals, a fault occurring on the line can be detected quickly. The detected fault is also displayed on the display unit 13, so that the operator can know the fault before actually dialing.

[0037]

As described above, according to the first aspect of the present invention, a call message with an unused number is transmitted to the exchange at predetermined intervals, so that a response message from the exchange is transmitted at predetermined intervals. receiving each can always obtain the end terminal apparatus capable of determining the usage of the line.

According to the second aspect of the present invention, the use status of the circuit switching channel determined in the first aspect of the present invention is displayed by the display means, so that the operator can quickly confirm the use status of the line. it is possible to obtain an end terminal device that Ru can.

According to a third aspect of the present invention, in the first and second aspects of the present invention, if a response message is not received even after a predetermined waiting time has elapsed, the circuit switching is performed.
It is determined that a channel failure has occurred. Therefore, automatically detectable end terminal device the occurrence of a failure is obtained.

[Brief description of the drawings]

FIG. 1 is a sequence diagram illustrating a flow of checking whether there is an empty channel according to the present embodiment.

FIG. 2 is a flowchart showing the operation of ISDN terminals 12a to 12h.

FIG. 3 is a system configuration diagram of a conventional ISDN indoor system.

FIG. 4 is a sequence diagram showing an example of the operation of the ISDN local area system shown in FIG. 3;

[Explanation of symbols]

 10 PBX 12a-12h ISDN terminal 13 Display

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04M 11/00 H04M 3/42 H04Q 3/58

Claims (3)

(57) [Claims] 1. An exchange connected to a plurality of circuit-switched channels.
A換機, the call message of unused number terminal
When receiving from the apparatus, when the line switching channel is used, all the first response message the terminal device of the content to the effect that the circuit switched channel is being used all
Returned to location, a second switch to return the response message to the terminal device, to the connected the terminal device of the content indicating that the no unused numbers are used when there is a vacancy in the circuit-switched channel In the above, to the exchange, a call message sending means for sending a call message of a predetermined unused number every predetermined period, receiving a response message returned from the exchange in response to the call message, The circuit switching if the response message is the first response message;
It determines that the channel is fully utilized, if the response message is the second response message before
Serial said end terminal device you comprising a line status determination means determines that the vacant exists, the circuit switching channel. 2. A end terminal device according to claim 1, wherein an end terminal device you comprising a display means, for displaying the status of the line is the result of determination by said line status determination means. 3. A end terminal device according to claim 1 or 2, wherein in a state where the line condition determining means does not receive said response message, the paging message transmission means a predetermined after sending the call message waiting when the time has elapsed, the line status determination means, circuit switching Cha
End terminal apparatus you and determines that the channel failure occurs.