JP6520584B2 - Telephone control device and telephone system - Google Patents

Description

  The present invention relates to a telephone control technology, and more particularly to an incoming call control technology for controlling notification of an incoming call from an upper IP telephone network to a lower telephone apparatus in accordance with a load condition in a lower telephone apparatus.

  A telephone control device such as a gateway that relays and connects the upper telephone network and the lower ISDN line or PSTN line is connected to the IP telephone network, which is the upper telephone network, via the IP line to make a virtual call path By forming a large number, voice calls with more telephone terminals can be realized in lower-level telephone devices including a main unit of a key telephone device and a private branch exchange device of a PBX system connected to the ISDN line or PSTN line. Have the function to In addition, some telephone devices such as a main device of a key telephone device and a private branch exchange device of a PBX system have a gateway function like the above-mentioned telephone control device.

  In such a telephone control device, in a situation where many incoming calls to the lower telephone devices are concentrated in the IP telephone network, if these incoming calls notified from the IP telephone network are centrally notified to the lower telephone devices, The processing load on the telephone device increases, which adversely affects other call control processing.

  Conventionally, as a technique for coping with such a situation, when the frequency of incoming calls per unit time is higher than a reference frequency, that is, when calls to a lower telephone device are concentrated in the IP telephone network, a telephone call is There is a technology for returning busy from the telephone control unit directly to the IP telephone network after waiting for a certain waiting time from notification of the incoming call from the IP telephone network without notifying the lower telephone device from the incoming call from the control device. It is proposed (for example, refer patent document 1 etc.).

  According to this, even if a busy return is made, a new incoming call is notified from the IP telephone network to the telephone control device, so a new incoming call will be notified to the subordinate telephone device. Only the waiting time can provide time for the subordinate telephone apparatus, and the incoming processing load can be reduced. This makes it possible to improve the high load situation in the lower telephone apparatus more quickly.

JP, 2013-157861, A

  However, in such prior art, when determining the necessity of the incoming call notification for the lower-level telephone device, the number of incoming call notifications from the IP telephone network is counted over a unit time such as 10 seconds, for example, and the obtained count is obtained. Based on whether the incoming call occurrence frequency obtained from the result is higher than the reference frequency, the necessity of incoming call notification is determined. For this reason, when incoming calls exceeding the reference frequency are extremely concentrated in a period shorter than unit time, for example, a few seconds, these incoming calls will be notified to the subordinate telephone device. Therefore, the burden of incoming call processing on the lower-level telephone device is not alleviated, but incoming call processing is rapidly increased, and as a result, other call control processing is adversely affected.

  Further, according to the prior art, since the necessity of incoming notification is determined based on the number of incoming notifications from the IP telephone network in unit time, any cause other than incoming, for example, download via the Internet etc. Even if the processing load on the telephone device increases, incoming calls are notified to the lower-level telephone devices as long as the number of incoming notification from the IP telephone network does not exceed the reference frequency. There is a problem that the processing burden of

  The present invention is intended to solve such problems, and an incoming call control technology capable of accurately determining whether or not incoming call notification to a subordinate telephone device is necessary even if the incoming call from the telephone network is extremely concentrated in a short period of time The purpose is to provide.

  In order to achieve such an object, the telephone control device according to the present invention is connected to the upper IP telephone network through the communication line and connected to the lower telephone device through the telephone line, and these IP telephones are connected. A telephone control apparatus having a gateway function for realizing voice communication by the telephone apparatus using the IP telephone network by relay connection between the network and the telephone apparatus, the call control message with the IP telephone network And notify the telephone device of an incoming call in response to an incoming message from the IP telephone network received by the message processing unit, and respond to a response notified from the telephone device in response to the incoming call A call control unit for transmitting a response message from the message processing unit to the IP telephone network, and the telephone in response to an incoming notification to the telephone apparatus. And an incoming call monitoring unit that increments the number of incoming calls processed in response to a response notification from the telephone device to the incoming call, and the call control unit limits the number of incoming calls processed to an upper limit process. If the number has been reached, the message processing unit transmits a busy message to the IP telephone network after waiting for a certain waiting time without notifying the telephone device of the incoming call. It is

  Further, in the above configuration example of the telephone control device according to the present invention, the call control unit determines that the waiting time is constant when the state in which the number of incoming call processing reaches the upper limit processing number continues for the upper limit continuation time or more. It is intended to be extended by the extension time.

  In one configuration example of the above-mentioned telephone control device according to the present invention, when the call control unit reaches the upper limit processing number, the incoming call message notified from the IP telephone network is an emergency call. In this case, the emergency call is notified to the telephone device without transmitting the busy message to the IP telephone network.

  A telephone system according to the present invention is a telephone control apparatus for realizing a call by the telephone terminal using the IP telephone network by switching and connecting a plurality of telephone terminals and the telephone terminals to the IP telephone network. And a message processing unit for exchanging call control messages with the IP telephone network, and a received message from the IP telephone network received by the message processing unit. And a call control unit for notifying the telephone terminal of an incoming call and transmitting a response message from the message processing unit to the IP telephone network in response to a response notified from the telephone terminal in response to the incoming call; The incoming call processing number is incremented in response to the incoming call notification to the telephone terminal, and the incoming call processing is performed in response to the response notification from the telephone terminal to the incoming call. And the call control unit does not notify the telephone terminal of the incoming call when the incoming call processing number reaches the upper limit processing number, and only for a predetermined waiting time. After waiting, a busy message is sent from the message processing unit to the IP telephone network.

  According to the present invention, the telephone device of the lower level receives an incoming call from the upper IP telephone network based on the current number of incoming calls notified from the telephone control device to the lower level telephone device, that is, the number of incoming calls processed. It is determined whether or not to notify. Therefore, instead of using the frequency of occurrence of incoming calls per unit time as in the conventional method, every time an incoming call is notified from the IP telephone network, the number of calls being received by the telephone device at that time is used for determination. . Therefore, even when the incoming call from the telephone network is concentrated in a short time from the unit time, it is possible to accurately determine whether the incoming call notification to the telephone device is necessary. As a result, it becomes possible to reduce the load on the incoming call processing in the lower telephone apparatus, and it is possible to reduce early the high load state occurring in the lower telephone apparatus due to factors other than the incoming call.

FIG. 1 is a block diagram showing a configuration of a telephone control device according to a first embodiment. It is a flowchart which shows the arrival processing of a telephone control unit. It is a flowchart which shows the incoming call monitoring process of a telephone control apparatus. It is a sequence diagram which shows the 1st operation example of a telephone control apparatus. It is a sequence diagram which shows the 2nd operation example of a telephone control unit. It is a block diagram which shows the structure of the telephone system concerning 2nd Embodiment.

Next, embodiments of the present invention will be described with reference to the drawings.
First Embodiment
First, with reference to FIG. 1, a telephone control apparatus 10 according to a first embodiment of the present invention will be described. FIG. 1 is a block diagram showing the configuration of the telephone control apparatus according to the first embodiment.

  The telephone control apparatus 10 as a whole comprises a gateway apparatus, and is connected to the IP telephone network 50 via the communication line 10A, and connected to the lower telephone apparatus 21 via the telephone line 10B. And the telephone device 21 to have a gateway function for realizing a voice call by the telephone device 21 using the IP telephone network 50.

  In the present embodiment, a case will be described as an example where the upper telephone network comprises the IP telephone network 50 and the lower telephone line 10B comprises the IP telephone line, the ISDN line or the PSTN line. When the telephone device 21 has only a function of connecting to an ISDN line or a PSTN line, call control or voice is performed between the IP telephone network and the ISDN line or PSTN line in the telephone control apparatus 10 as in the present embodiment. By performing the conversion process related to the above, the use of the IP telephone network 50 by the telephone device 21 becomes possible.

The telephone system 20 is formed of, for example, a telephone system such as a key telephone apparatus or a PBX system, and the telephone apparatus 21 corresponds to a main apparatus or private branch exchange apparatus of these telephone systems.
The telephone device 21 connects to a plurality of telephone terminals 23 via the extension line 22 and exchanges and connects the telephone terminal 23 to the telephone line 10B, thereby realizing voice communication by the telephone terminal 23 using the telephone line 10B. Have a function to In the present embodiment, although the case where the lower-level telephone device is composed of the telephone device 21 will be described as an example, the present invention is not limited to this and may be a general single telephone device for making a voice call. .

  In the present embodiment, the incoming call monitoring unit 14 increments the number of incoming calls processed by the telephone device 21 in response to an incoming call notification to the telephone device 21, and the incoming call processing in response to a response notification from the telephone device 21 to the incoming call. When the call processing unit 16 decrements the number and the call processing unit 16 reaches the upper limit processing number, it does not notify the telephone device 21 of the incoming call, and waits for a certain waiting time, and then the IP telephone network A busy message is sent to 50.

[Phone control unit]
Next, the configuration of the telephone control apparatus 10 according to the present embodiment will be described in detail with reference to FIG.
The telephone control device 10 as a whole comprises a computer such as a server device, and as main functional units, the network I / F unit 11, the message processing unit 12, the line I / F unit 13, the incoming call monitoring unit 14, the storage unit 15, A call control unit 16 and an application processing unit 17 are provided.

  The network I / F unit 11 comprises a dedicated communication interface circuit and has a function of transmitting and receiving a call control message and voice data by performing data communication with the IP telephone network 50 via the communication line 10A. ing.

  The message processing unit 12 has a function of exchanging a call control message based on a call control protocol such as SIP (Session Initiation Protocol) with the IP telephone network 50 via the network I / F unit 11, and an IP telephone network 50. Function of notifying the call control unit 16 of the contents of various call control messages such as an incoming call message notified from the call control unit 16 and, according to an instruction from the call control unit 16, an instructed call control message such as a busy message And a function to notify 50.

  The line I / F unit 13 is formed of a dedicated communication interface circuit, and communicates with the telephone device 21 through the telephone line 10B, based on a call control method used in an ISDN line or a PSTN line. , Has a function of transmitting and receiving a call control message (call control signal) and voice data (voice signal).

  The incoming call monitoring unit 14 has a function of incrementing the number of incoming calls processed by the telephone device 21 in response to an incoming call notification to the telephone device 21 and a function of decrementing the number of incoming calls processing in accordance with a response notification from the telephone device 21 to the incoming call. And.

  The incoming call processing number is the current number of incoming calls notified from the telephone control apparatus 10 to the lower telephone apparatus 21. Also, the incoming call referred to here is a call that has been notified to the telephone device 21 to the last, but the incoming call has not been accepted by the telephone device 21 yet. Specifically, it is defined as a call which has notified the incoming call notification message to the telephone device 21 but has not notified the primary response message or the final response message to the incoming call notification from the telephone device 21.

  For example, when the telephone device 21 is SIP compatible, the incoming notification message, the primary response message, and the final response message correspond to the INVITE, 180 Ringing, and 200 OK messages, respectively. When the telephone device 21 is compatible with ISDN, the incoming call notification message, the primary response message, and the final response message correspond to the SETUP, ALERT / PROG, and CONNECT messages, respectively.

The storage unit 15 is formed of a storage device such as a semiconductor memory or a hard disk, and has a function of storing the call control information 15A and the program 15P.
The call control information 15A includes, for example, the use status of each communication line capable of establishing a voice call with the IP telephone network 50 on the communication line 10A, the use status of each telephone line 10B connected between the telephone apparatus 21 and the like. It consists of various control information used for call control processing in the call control unit 16.
The program 15P is a program for realizing the message processing unit 12, the incoming call monitoring unit 14, and the call control unit 16 by being read and executed by the CPU. It is stored in advance in the storage unit 15 from an external device or a recording medium (both not shown).

  The call control unit 16 exchanges various call control messages with the IP telephone network 50 via the message processing unit 12, and performs various calls with the telephone apparatus 21 via the line I / F unit 13. The function of realizing voice communication by the telephone apparatus 21 using the IP telephone network 50 by relaying and connecting the IP telephone network 50 and the telephone apparatus 21 by exchanging control data and a call control signal, and each telephone line The function of determining whether the telephone apparatus 21 responds to an incoming call notified from the IP telephone network 50 based on the use status of 10 B, and all available lines are in use in each telephone line 10 B, and the telephone apparatus 21 It has a function of returning a busy message from the message processing unit 12 to the IP telephone network 50 when it can not respond to an incoming call.

  Further, when the incoming call processing number Rcnt counted by the incoming call monitoring unit 14 has reached the upper limit processing number Rlim, the call control unit 16 does not notify the telephone device 21 of an incoming call, and a certain waiting time is set. After waiting for Tw, the function of sending a busy message from the message processing unit 12 to the IP telephone network 50 and the state where the number of incoming calls processed Rcnt has reached the upper limit processed number Rlim continues for the upper limit duration time Tlim or more. A function to extend the waiting time Tw by a fixed extension time Tex, and a busy message if the incoming message notified from the IP telephone network 50 indicates an emergency call when the incoming call processing number Rcnt has reached the upper limit processing number Rlim And the function of notifying the telephone apparatus 21 of the emergency call without transmitting the

  Generally, the incoming call notification message from the IP telephone network 50 includes the calling party's telephone number. Therefore, the calling party's telephone number for making an emergency call is registered in advance in the emergency call list, and the calling party's telephone number included in the incoming call notification message from IP telephone network 50 is compared with the emergency call list. It can be determined whether the incoming call notified by the incoming call notification message is an emergency call.

  The application processing unit 17 includes voice data exchanged with the IP telephone network 50 via the network I / F unit 11 and voice data or voice exchanged with the telephone device 21 via the line I / F unit 13. It has a function of mutually converting signals and switching connection.

  With regard to the upper limit processing number Rlim and the upper limit duration time Tlim, the number of telephone lines that can establish a voice call with the IP telephone network 50 on the communication line 10A, and the telephone line of the telephone line 10B connected between the telephone device 21 The number may be set in the storage unit 15 in advance in consideration of the processing capability of the call control unit 16 (CPU), the processing capability of the telephone device 21, and the like.

[Operation of First Embodiment]
Next, the operation of the telephone control apparatus 10 according to the present embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart showing an incoming process of the telephone control device. FIG. 3 is a flowchart showing an incoming call monitoring process of the telephone control device. Hereinafter, the case where the telephone device 21 is compatible with ISDN will be described as an example.

  First, with reference to FIG. 2, an incoming call process in the telephone control device 10 according to the present embodiment will be described. The call control unit 16 of the telephone control device 10 is notified of an incoming call from the IP telephone network 50 via the message processing unit 12 and executes the incoming call process of FIG. 2 when there is a usable line among the telephone lines 10B. .

First, the call control unit 16 acquires the current incoming call processing number Rcnt from the incoming call monitoring unit 14 (step 100), and compares the incoming call processing number Rcnt with the upper limit processing number Rlim (step 101).
Here, if Rcnt <Rlim and Rcnt has not reached Rlim (step 101: YES), the call control unit 16 selects an available free line of the telephone line 10B, and the line I / F unit At 13, an incoming call is notified to the telephone device 21 via the vacant line (step 102), and a series of incoming call processing is ended.

  On the other hand, if Rcnt ≧ Rlim and Rcnt has reached Rlim (step 101: NO), the call control unit 16 waits for a fixed waiting time Tw (step 103), and then transmits a busy message for the incoming call to The message processing unit 12 sends back to the IP telephone network 50 via the network I / F unit 11 (step 104), and a series of incoming call processing is completed.

  Next, with reference to FIG. 3, an incoming call monitoring process in the telephone control apparatus 10 according to the present embodiment will be described. The incoming call monitoring unit 14 of the telephone control device 10 executes the incoming call monitoring process of FIG. 3 for each call control message exchanged between the call control unit 16 and the telephone device 21.

  First, when the call control message exchanged between the call control unit 16 and the telephone device 21 is an incoming call notification (SETUP) to the telephone device 21 (step 110: YES), the number of incoming calls processed Rcnt is incremented (Rcnt = Rcnt + 1) (step 111), and a series of incoming call monitoring processing is ended.

  On the other hand, when the call control message is not the incoming call notification (SETUP) (NO at step 110) but a primary response (Alert) from the telephone apparatus 21 (step 112: YES), the incoming call monitoring unit 14 determines the number of incoming calls Rcnt. Is decremented (Rcnt = Rcnt-1) (step 115), and a series of incoming call monitoring processing is ended.

  If the call control message is not the primary response (Alert) (Step 112: NO) but the final response (Connect) from the telephone apparatus 21 (Step 113: YES), the incoming call monitoring unit 14 determines the number of incoming calls Rcnt. Is decremented (Rcnt = Rcnt-1) (step 115), and a series of incoming call monitoring processing is ended.

If the call control message is not the final response (Connect) (NO at step 113) but an error response (Release) from the telephone apparatus 21 (YES at step 114), the incoming call monitoring unit 14 determines the number of incoming calls Rcnt. Is decremented (Rcnt = Rcnt-1) (step 115), and a series of incoming call monitoring processing is ended.
When the call control message is not an error response (Release) (step 114: NO), the incoming call monitoring unit 14 does not change the number of incoming calls processed Rcnt, and ends the series of incoming call monitoring processing.

[First operation example]
Next, a first operation example of the telephone control device 10 according to the present embodiment will be described with reference to FIG. FIG. 4 is a sequence diagram showing a first operation example of the telephone control device. Here, when a high load occurs in the telephone device 21 and the incoming call from the IP telephone network 50 is not notified from the telephone control device 10 to the telephone device 21, the high load is ended and the telephone device 21 is notified Will be described as an example. Below, the case where the telephone control apparatus 10 is SIP-compliant and the telephone apparatus 21 is ISDN-compliant will be described as an example.

  As shown in FIG. 4, in the initial state before time T0, there is no incoming call notified from the telephone control apparatus 10 to the lower telephone apparatus 21 and the number of incoming calls processed Rcnt is "0". I assume. Further, it is assumed that "30" is set as the upper limit processing number Rlim, and "2 sec" is set as the waiting time Tw.

  When incoming call (INVITE) is notified from the IP telephone network 50 at time T0, Rcnt = 0 is confirmed in the telephone control unit 10, and Rcnt <1. An incoming call (Setup) is notified. In response to this, the call setup acceptance (CallProc) is returned from the telephone device 21, and then the primary response (Alert) is returned. In response to the primary response (Alert), the telephone control apparatus 10 decrements Rcnt = 0 and notifies the IP telephone network 50 of the primary response (180 Ringing).

  Thereafter, when the telephone apparatus 21 generates a high load at time T1 and the incoming call (INVITE) is notified from the IP telephone network 50 at time T2, the telephone control apparatus 10 confirms Rcnt = 0, and Rcnt < Since Rlim is set, Rcnt is incremented to 1, and the incoming call (Setup) is notified to the telephone device 21. In response to this, the call setting acceptance (CallProc) is returned from the telephone device 21.

Here, since a high load occurs in the telephone control device 10, it is assumed that the return of the primary response (Alert) thereafter is delayed, and subsequently, the incoming call to the telephone device 21 is concentrated in the IP telephone network 50. It is assumed that the event occurs and Rcnt is incremented to 30.
Therefore, when incoming call (INVITE) is notified from IP telephone network 50 at subsequent times T3 and T4, this incoming call is not notified from telephone control device 10 to telephone device 21 because Rcnt = 30 ≧ Rlim. At times T5 and T6 after waiting for waiting time Tw = 2 sec, busy (486 Busy Here) is returned from the telephone control device 10 to the IP telephone network 50, respectively.

  After that, when the high load on the telephone device 21 ends at time T7, and the primary response (Alert) is returned from the telephone device 21 at times T8 and T9 thereafter, the telephone control device 10 causes Rcnt = 29, 28. Each is decremented, and a primary response (180 Ringing) is notified to IP telephone network 50.

  Therefore, when incoming call (INVITE) is notified from the IP telephone network 50 at time T10 after that, Rcnt = 28 is confirmed in the telephone control apparatus 10, and Rcnt <Rlim, so Rcnt = 1 is incremented, The incoming call (Setup) is notified to the telephone device 21.

[Second operation example]
Next, a second operation example of the telephone control apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 5 is a sequence diagram showing a second operation example of the telephone control device. Here, a case where a high load occurs in the telephone device 21 and a state in which the incoming call processing number Rcnt has reached the upper limit processing number Rlim continues for the upper limit continuation time Tlim or more will be described as an example. Below, the case where the telephone control apparatus 10 is SIP-compliant and the telephone apparatus 21 is ISDN-compliant will be described as an example.

  As shown in FIG. 5, it is assumed that a high load is generated in the telephone device 21 before time T20, and the incoming call processing number Rcnt is "29". Further, it is assumed that "30" is set as the upper limit processing number Rlim, and "2 sec" is set as the waiting time Tw.

  When incoming call (INVITE) is notified from the IP telephone network 50 at time T20, Rcnt = 29 is confirmed in the telephone control unit 10, and Rcnt <30, so that Rcnt = 30 and incremented to the telephone apparatus 21. An incoming call (Setup) will be notified. However, since the telephone apparatus 21 is in a high load state, no response is returned to the telephone control apparatus 10. Further, when Rcnt = 30, clocking of the duration time Tb is started.

  When the incoming call (INVITE) is notified from the IP telephone network 50 at the subsequent time T21, since Rcnt = 30 ≧ Rlim, this incoming call is not notified from the telephone control apparatus 10 to the telephone apparatus 21, and the waiting time Tw = At time T22 when waiting for 2 seconds, the telephone control unit 10 returns a busy (486 Busy Here) to the IP telephone network 50.

Thereafter, at time T23 when the duration Tb reaches the upper limit duration Tlim, the waiting time Tw = 2 sec is extended by the extension time Tex = 0.5 sec and changed to Tw = 2.5 sec.
Therefore, when an incoming call (INVITE) is notified from IP telephone network 50 at time T24 after this, since Rcnt = 30RRlim, this incoming call is not notified from telephone control device 10 to telephone device 21, At time T25 when waiting time Tw = 2.5 seconds, busy (486 Busy Here) is returned from the telephone control apparatus 10 to the IP telephone network 50.

Thereafter, when the high load ends at time T26 in the telephone device 21 and the primary response (Alert) is returned from the telephone device 21 at time T27 thereafter, the telephone control device 10 is decremented to Rcnt = 29, and IP The telephone network 50 is notified of the primary response (180 Ringing).
As a result, since Rcnt <Rlim, Tb = 0 and Tw = 2 sec are respectively reset.

[Effect of First Embodiment]
As described above, according to the present embodiment, the incoming call monitoring unit 14 increments the incoming call processing number Rcnt in the telephone device 21 in response to the incoming call notification to the lower telephone device 21 and notifies the telephone device 21 of the response to the incoming call. In response to this, the incoming call processing number Rcnt is decremented, and when the incoming call processing number Rcnt reaches the upper limit processing number Rlim in the call control unit 16, the incoming call is not notified to the telephone device 21, and a certain waiting time After waiting for Tw, the message processor 12 sends a busy message to the IP telephone network 50.

  As a result, based on the current number of incoming calls notified from the telephone control apparatus 10 to the subordinate telephone apparatus 21, that is, the incoming call processing number Rcnt, the incoming call from the superior IP telephone network 50 is called the subordinate telephone It is determined whether to notify the device 21 or not. For this reason, instead of using the frequency of occurrence of incoming calls per unit time as in the conventional method, every time an incoming call is notified from the IP telephone network 50, the number of calls being received by the telephone device 21 at that time is determined. Used. Therefore, even when the incoming call from the telephone network 50 is concentrated in a short time from the unit time, it is possible to accurately determine whether the incoming call notification to the telephone device 21 is necessary or not, and as a result, the incoming call processing in the lower telephone device 21 It is possible to reduce the burden.

  Further, when the telephone apparatus 21 is in a high load state due to reasons other than the incoming process and the response to the incoming call notified to the telephone apparatus 21 is not notified from the telephone apparatus 21, the incoming process count Rcnt is not decremented and the upper limit process is performed. Since the state reaches the number Rlim, even if a new incoming call is notified from the upper IP telephone network 50, further incoming call notification to the telephone device 21 can be suppressed. Therefore, if the processing load on the telephone device 21 is increased due to reasons other than incoming call processing, such as downloading via the Internet, for example, the additional processing load due to the incoming call processing on the telephone device 21 is avoided. It is possible to reduce the high load condition in the device 21 early.

  Further, in the present embodiment, when the state in which the number of incoming calls Rcnt reaches the upper limit number of processing Rlim continues for the upper limit continuation time Tlim or more by the call control unit 16, the waiting time Tw is extended by a fixed extension time Tex. You may do so. Thereby, the high load continuing for a long time in the lower telephone device 21 can be eliminated earlier.

  Further, in the present embodiment, when the incoming call processing number Rcnt reaches the upper limit processing number Rlim by the call control unit 16, if the incoming call message notified from the IP telephone network 50 indicates an emergency call, the IP telephone network The emergency call may be notified to the subordinate telephone device 21 without making a busy message to 50. As a result, even if the telephone device 21 is heavily loaded, the emergency call is immediately notified to the telephone device 21, and the emergency call can be prioritized.

  Further, in the present embodiment, as a method of determining whether or not the waiting time Tw needs to be extended, Tb starts counting when the incoming call processing number Rcnt reaches the upper limit processing number Rlim, and this Tb becomes the upper limit continuation time Tlim. Although the case where Tb is extended when reached is described as an example, it is not limited to this. For example, when the call control unit 16 determines, for each unit time, whether or not the incoming call processing number Rcnt has reached the upper limit processing number Rlim and holds it, and returns a busy message, from the point of time Whether the waiting time Tw needs to be extended may be determined based on whether or not the latest determination result for the upper limit continuation time Tlim indicates that all the incoming call processing number Rcnt has reached the upper limit processing number Rlim. As a result, there is no need to measure Tb, and the processing load on the call control unit 16 can be reduced.

Second Embodiment
Next, with reference to FIG. 6, a telephone system 30 according to a second embodiment of the present invention will be described. FIG. 6 is a block diagram showing the configuration of the telephone system according to the second embodiment.
In the first embodiment, the case where the telephone control apparatus 10 is formed by the gateway apparatus that relays and connects the upper IP telephone network 50 and the lower telephone apparatus 21 has been described as an example. In the present embodiment, a case will be described where the telephone control device 10 comprises a main unit of a key telephone unit and a private branch exchange unit of a PBX system.

  The telephone control apparatus 10 according to the present embodiment is connected to the IP telephone network 50 via the communication line 10A, and connected to the telephone terminal 31 via the extension line 10C, and the IP telephone network 50 and the telephone terminal 31 are connected. , And has a function of realizing a voice call by the telephone terminal 31 using the IP telephone network 50. A telephone system 30 is configured of the telephone control device 10 and the telephone terminal 31.

The telephone control unit 10 is generally composed of a computer such as a server unit, and as main functional units, the network I / F unit 11, the message processing unit 12, the line I / F unit 13, the incoming call monitoring unit 14, the call control unit 16 and a storage unit 15 are provided.
These functional units have the same functions as those of the first embodiment.

  The network I / F unit 11 comprises a dedicated communication interface circuit and has a function of transmitting and receiving a call control message and voice data by performing data communication with the IP telephone network 50 via the communication line 10A. ing.

  The message processing unit 12 has a function of exchanging a call control message based on a call control protocol such as SIP with the IP telephone network 50 via the network I / F unit 11, and an incoming call notified from the IP telephone network 50. A function of notifying the call control unit 16 of the contents of various call control messages such as a message, and a function of notifying the IP telephone network 50 of the instructed call control message such as a busy message according to an instruction from the call control unit 16 And.

  The line I / F unit 13 comprises a dedicated communication interface circuit and has a function of transmitting and receiving a call control message and voice data by communicating with the telephone terminal 31 via the extension line 10C. .

  The incoming call monitoring unit 14 has a function of incrementing the incoming call processing number Rcnt in the telephone control apparatus 10 in response to an incoming call notification to the telephone terminal 31, and the incoming call processing number Rcnt in response to a response notification from the telephone terminal 31 to the incoming call. It has a function to decrement.

The storage unit 15 is formed of a storage device such as a semiconductor memory or a hard disk, and has a function of storing the call control information 15A and the program 15P.
The call control information 15A includes, for example, the use status of each communication line capable of establishing a voice call with the IP telephone network 50 on the communication line 10A, the use status of each extension line 10C connected between the telephone terminal 31, and the like. It consists of various control information used for call control processing in the call control unit 16.
The program 15P is a program for realizing the message processing unit 12, the incoming call monitoring unit 14, and the call control unit 16 by being read and executed by the CPU. It is stored in advance in the storage unit 15 from an external device or a recording medium (both not shown).

  The call control unit 16 exchanges various call control messages with the IP telephone network 50 via the message processing unit 12, and performs various calls with the telephone terminal 31 via the line I / F unit 13. The function of realizing voice communication by the telephone terminal 31 using the IP telephone network 50 by exchanging and connecting the IP telephone network 50 and the telephone terminal 31 by exchanging control data and call control signals, and each extension line The function to determine whether or not to answer the incoming call notified from the IP telephone network 50 based on the usage condition of 10C at the telephone terminal 31, and all the telephone terminals 31 are in use and can not answer the incoming call at the telephone terminal 31 In this case, it has a function of returning a busy message from the message processing unit 12 to the IP telephone network 50.

  Further, when the incoming call processing number Rcnt counted by the incoming call monitoring unit 14 has reached the upper limit processing number Rlim, the call control unit 16 does not notify the telephone terminal 31 of an incoming call, and a certain waiting time is set. After waiting for Tw, the function of sending a busy message from the message processing unit 12 to the IP telephone network 50 and the state where the number of incoming calls processed Rcnt has reached the upper limit processed number Rlim continues for the upper limit duration time Tlim or more. A function to extend the waiting time Tw by a fixed extension time Tex, and a busy message if the incoming message notified from the IP telephone network 50 indicates an emergency call when the incoming call processing number Rcnt has reached the upper limit processing number Rlim And the function of notifying the telephone terminal 31 of the emergency call.

  The application processing unit 17 includes voice data exchanged with the IP telephone network 50 via the network I / F unit 11 and voice data or voice exchanged with the telephone terminal 31 via the line I / F unit 13. It has a function of mutually converting signals and switching connection.

[Operation of Second Embodiment]
The incoming call processing and incoming call monitoring processing of the telephone control apparatus 10 according to the present embodiment are substantially the same as FIGS. 2 and 3 described in the first embodiment described above. In particular, if the lower telephone device 21 in FIG. 2 and FIG. 3 is replaced with the telephone terminal 31, it can be applied in the same manner as described above.

[Effect of Second Embodiment]
As described above, in the present embodiment, the telephone control device 10 is not the gateway device but the main device of the key telephone device or the private branch exchange device of the PBX system, but the operation is the same as in the first embodiment. Do. That is, the incoming call monitoring unit 14 increments the incoming call processing number Rcnt in response to the incoming call notification to the lower telephone terminal 31, and decrements the incoming call processing number Rcnt in response to the response notification from the telephone terminal 31 to the incoming call. If the incoming call processing number Rcnt in the unit 16 has reached the upper limit processing number Rlim, the incoming call is not notified to the telephone terminal 31, and after waiting for a certain waiting time Tw, the IP telephone from the message processing unit 12 A busy message is sent to the network 50.

  As a result, the telephone terminal 31 receives an incoming call from the upper IP telephone network 50 based on the current number of incoming calls notified from the telephone control apparatus 10 to the lower telephone terminals 31, that is, the reception processing number Rcnt. It is determined whether or not to notify. For this reason, as compared with the conventional method using the frequency of occurrence of incoming calls per unit time, every time an incoming call is notified from the IP telephone network 50, the number of calls being processed by the telephone control apparatus 10 at that time is determined Used. Therefore, even when incoming calls from the telephone network 50 are concentrated in a short period of time from unit time, it is possible to accurately determine whether the incoming call notification to the telephone terminal 31 is necessary or not. It is possible to reduce.

[Extension of the embodiment]
As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is not limited to the said embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. Moreover, about each embodiment, it can combine arbitrarily and can be implemented in the not conflicting range.

  In the above embodiments, the call processing end message is not limited to the 486 message (Busy Here) in the case of SIP, and the same return waiting is applied to the 400th, 500th, and 600th messages. You may Note that the call control protocol is not limited to SIP, and H. The other embodiments of the present invention can be applied to other call control protocols such as H.323 in the same manner as described above, and similar operations and effects can be obtained.

  10: telephone control unit, 10A: communication line, 10B: telephone line, 10C: extension line, 11: network I / F unit, 12: message processing unit, 13: line I / F unit, 14: incoming call monitoring unit, 15 ... storage unit, 15A ... call control information, 15P ... program, 16 ... call control unit, 20 ... telephone system, 21 ... telephone device, 22 ... extension line, 23 ... telephone terminal, 30 ... telephone system, 31 ... telephone terminal, 50: IP telephone network, Rcnt: incoming processing number, Rlim, upper limit processing number, Tw, waiting time, Tex, extension time, Tb, duration time, Tlim, upper limit duration time.

Claims (4)

The IP telephone network is connected by connecting to the upper IP telephone network through the communication line and connecting to the lower telephone apparatus through the telephone line, and relay connecting the IP telephone network and the telephone apparatus. A telephone control device having a gateway function for realizing a voice call by the telephone device, comprising:
A message processing unit that exchanges call control messages with the IP telephone network;
In response to an incoming message from the IP telephone network received by the message processing unit, the incoming call is notified to the telephone device, and in response to a response notified from the telephone device in response to the incoming call, the message processing unit A call control unit that sends a response message to the IP telephone network;
An incoming call monitoring unit which increments the number of incoming calls processed by the telephone device in response to an incoming call notification to the telephone device, and decrements the number of incoming calls processing in response to a response notification from the telephone device to the incoming call;
The call control unit does not notify the telephone apparatus of the incoming call when the incoming call processing number reaches the upper limit processing number, and after waiting for a fixed waiting time, the message processing unit A telephone control apparatus characterized by transmitting a busy message to an IP telephone network. In the telephone control device according to claim 1,
The telephone control apparatus, wherein the call control unit extends the waiting time by a predetermined extension time when the state in which the number of incoming calls reaches the upper limit processing continues for an upper limit continuation time or more. In the telephone control device according to claim 1 or 2,
The call control unit transmits the busy message to the IP telephone network if the incoming message notified from the IP telephone network indicates an emergency call when the number of incoming calls reaches the upper limit processing number. A telephone control apparatus, wherein the emergency call is notified to the telephone apparatus without being performed. A telephone system comprising: a plurality of telephone terminals; and a telephone control device for realizing a call by the telephone terminal using the IP telephone network by switching and connecting the telephone terminals to the IP telephone network,
The telephone control device
A message processing unit that exchanges call control messages with the IP telephone network;
An incoming call is notified to the telephone terminal in response to an incoming message from the IP telephone network received by the message processing unit, and in response to a response notified from the telephone terminal in response to the incoming call, the message processing unit A call control unit that sends a response message to the IP telephone network;
A call reception monitoring unit that increments the number of incoming calls according to a notification of incoming calls to the telephone terminal, and decrements the number of incoming calls according to a notification of a response from the telephone terminal to the incoming call;
The call control unit does not notify the telephone terminal of the incoming call when the incoming call processing number reaches the upper limit processing number, and after waiting for a certain waiting time, the message processing unit A telephone system characterized by transmitting a busy message to an IP telephone network.

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