JP3128356B2 - Electronic exchange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic exchange provided with an interface for connecting to an ISDN network.

[0002]

2. Description of the Related Art In a conventional electronic exchange, ISDN is used.
When a call setup signal is transmitted to the network, if there is no response from the ISDN network for any reason, the caller has no alternative but to disconnect the call.

[0003]

Conventionally, when a call setup signal is transmitted to an ISDN and there is no response to the call setup signal,
The caller had no choice but to hang up the call, and couldn't tell if there was simply no response from the network or if there was some failure in the network. Therefore, even if there is some failure in the network and it is impossible to return a response, attempts to seize the trunk connected to the failed network without knowing it are repeated, and each time it is disconnected As a result, there is a problem that the call loss increases and an outside line is hardly applied.

Accordingly, the present invention eliminates such a problem, and when a response to the call setting signal is not returned from the network due to some kind of fault in the network, the control which issues the call setting signal is performed. An object of the present invention is to block a channel so that a trunk controlled by another control channel can be captured and transmitted.

[0005]

SUMMARY OF THE INVENTION According to the present invention, in an electronic exchange having at least one interface for connecting to an ISDN network, a response signal to a call setup signal transmitted to the ISDN network is transmitted from the ISDN network. An electronic exchange having monitoring means for monitoring whether or not the abnormality has been detected, abnormality detecting means for detecting an abnormality associated with the monitoring means, and display means for displaying the fact when the abnormality is detected I will provide a.

[0006]

When the terminal sends a call setup signal to the ISDN network, the monitoring means monitors whether or not there is a response from the ISDN network. For example, if there is a predetermined number of cases in which a predetermined time elapses without a response, the detection unit determines that there is an abnormality, and the display unit displays that fact. In the preferred embodiment, the control channel in which the abnormality is detected is closed. As a result, an outside line can be transmitted using another control channel, and a call loss caused by reusing the control channel in which the abnormality is detected is reduced.

[0007]

FIG. 1 is a block diagram showing the configuration of one embodiment according to the present invention. Reference numeral 1 denotes an electronic exchange, which has a CPU 7 for controlling the entire electronic exchange system. A database 8 is connected to the CPU 7, and the database 8 stores the number of timeouts of a call setting non-response timer described later and a threshold value for determining an abnormality.
Per Call and ISDN Interface Group (IFG)
Each time, a map as shown in FIGS. 2 to 4 is stored. ISDN trunk interfaces 4a-4
b are connected to interface groups (IFGs) 3a to 3b of the ISDN 2 respectively, the extension interface 6 is connected to extension terminals 9a to 9c, and the communication path between the interfaces 4a, 4b, 6 is controlled by the CPU 7. , And can be selectively connected / disconnected by a time switch (TSW) 5. CPU 7 also
It is connected to the maintenance console 10 of this system.

In such a configuration, an extension terminal 9
The operation according to the present invention when a call is made to ISDN 2 from FIG.
This will be described with reference to the flowcharts of FIGS. First, it is assumed that the extension terminal 9a has transmitted using the second IFG 3b. An identifier for identifying this call is icn1. In this case, processing is first performed according to FIG. That is, in response to the call signal from the extension terminal 9a, the non-response timer is set and the time measurement is started. And ISDN
A call setting signal is transmitted to the network 2 through the second IFG 3b. Here, the ISDN network 2 and the trunk interface 4
b, etc., if there is no abnormality, a signal indicating that the call setting signal has been accepted (call setting acceptance signal) is sent back from the ISDN 2 and received by the ISDN trunk interface, and the CPU 7
And the processing is performed according to FIG. That is, ISD
When the call setting acceptance signal from N network 2 is received, since there is no abnormality, the counter (see FIGS. 2 and 4) indicating the number of times the non-response timer has timed out is reset to zero for each of call icn1 and second IFG 3b. Is done.

Next, suppose that the extension terminal 9a originated a call to the ISDN network 2 using the first IFG 3a. An identifier for identifying this call is icn2. In this case, similarly, processing is first performed in accordance with FIG. 5, a non-response timer is set, and a call setting signal is sent to the ISDN. In this case, it is assumed that there is no response from the ISDN 2 and the non-response timer times out. Then Figure 8
The processing is performed according to. First, since the non-response timer times out, the count of the timeout counter (see FIG. 2) assigned to the first IFG 3a is increased by one, and the count of the timeout counter assigned to the call icn2 is also increased by one. . In this case, as shown in FIG. 2, assuming that the number of timeouts of the first IFG 3a until now is “9”, adding 1 to this results in “1”.
0 ". Further, as shown in FIG. 4, if the current value of the timeout count of the call icn2 is “0”, adding 1 to this results in “1”. Here, a preset threshold value for abnormality determination is compared with the number of times of timeout of the first IFG 3a. At this time, if the threshold value of the first IFG 3a is not set as shown in FIG. 2, the default value shown in FIG.
The threshold is “10”. Therefore, since the number of timeouts of the first IFG 3a is not greater than the threshold value, the determination result is "NO", and then the number of timeouts of the call icn2 is compared with a threshold value (for example, fixed to "1"). Is performed. Here, the number of timeouts of the call icn2 is “1” as described above, and since this value is not larger than the threshold value “1”, the determination result is “N”.
O ". In this case, subsequently, the non-response timer is reset to start the measurement again, and to send the call setting signal to the ISDN network 2 again.

In this state, if there is no response from the ISDN network 2 again and the non-response timer times out, the processing is performed again according to FIG. First, the count of the timeout counter of the first IFG 3a is increased from "10" by 1 to "11", and the count of the timeout counter of the call icn2 is also increased by 1 from "1" to "2".
Becomes Here, the count number of the first IFG 3a is compared with the threshold value “10”. This time, the count number is larger, and the determination result is “YES”. This means that there is an abnormality, and the first IFG 3a Is blocked, and a blocking release timer is set (the operation relating to this blocking release timer will be described later with reference to FIG. 7). Subsequently, the call icn2 and the 1st I shown in FIGS.
The timeout count of the FG 3a is reset to “0” and the call is disconnected. Then, the maintenance console 10 is notified that there is an abnormality. At this time, the originating terminal 9a may be notified of the abnormality using a message or a ringtone.

Next, regarding the above-mentioned blockage release timer,
This will be described with reference to FIG. As described above, if an abnormality is detected in the control channel used when capturing the ISDN network,
This control channel is blocked, and a blocking release timer is set. If the blockage release timer times out in this state, the blockage is automatically released and the maintenance console 10
Indicates that the blockage was released for. As a result, the blockage can be released without bothering the maintenance person. At this time, the terminal may be notified of the blockage release using a message or a ringtone.

By the way, if the timeout number of the non-response timer of the IFG is not greater than the threshold value, but the timeout number of the call is greater than the threshold value "1", as shown in FIG. Only the timeout count is reset to “0” and the call is disconnected.

[0013]

As described above, according to the present invention, I
When a call is transmitted to the SDN network, an abnormality caused by the communication path can be detected by monitoring whether or not there is a response from the network side to the call, and all control channels in which the abnormality is detected are blocked. be able to. As a result, an outside line can be transmitted using another control channel, and call loss due to an abnormality in the communication path is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a table showing a threshold value and a call setting non-response timer timeout count for each interface group in the embodiment.

FIG. 3 shows a default threshold value when no threshold value is set in the embodiment.

FIG. 4 is a table showing the number of timeouts of a call setting non-response timer for each call in the embodiment.

FIG. 5 is a flowchart showing a processing flow at the time of transmitting a call setting signal in the embodiment.

FIG. 6 is a follow chart showing a processing flow at the time of receiving a call setting acceptance signal in the embodiment.

FIG. 7 is a flowchart showing a processing flow when a blockage release timer times out in the embodiment.

FIG. 8 is a flowchart showing a processing flow when a non-response timer times out in the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electronic exchange 2 ISDN network 3 ISDN network interface group (IFG) 4 ISDN trunk interface 5 time switch (TSW) 6 extension interface 7 CPU 8 database 9 extension terminal

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04M 3/08

Claims (3)

(57) [Claims] An electronic exchange having at least one interface for connecting to a plurality of communication lines, wherein a response signal to a call setting signal transmitted to each of the plurality of communication lines is transmitted from the corresponding one of the communication lines. A monitoring means for monitoring whether or not a response signal to the call setting signal is not returned within a predetermined period for each of the communication lines;
A counting unit; a disconnecting unit that disconnects the corresponding communication line when the number of times measured by the first counting unit exceeds a predetermined threshold; and a disconnection unit that is disconnected by the disconnecting unit among the plurality of communication lines. Second counting means for measuring the number of lines that have been set, and determining means for determining that there is an abnormality in the interface when the number of times measured by the second counting means exceeds a predetermined threshold value. Electronic exchange characterized. 2. The electronic exchange according to claim 1, further comprising display means for displaying when the abnormality is judged to be abnormal by said judgment means. 3. The electronic exchange according to claim 1, further comprising a closing unit for closing a line group to which the interface having the abnormality belongs when the determining unit determines that there is an abnormality. .