JP2004128891A - Audio gateway unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an audio gateway unit for easily introducing IP telephone service in an environment where a private telephone exchange is used. <P>SOLUTION: A communication system comprising the audio gateway unit 30 is nearly made up of a telephone terminal 10, the private telephone exchange 20, the audio gateway unit 30, a call agent 40, an IP network 7, and a public telephone network 8. The audio gateway unit 30 connects office lines 9 from the private telephone exchange 20, subscriber lines 4, and an xDSL modem 1 for transmitting/receiving a digital signal over the subscriber lines 4 together; carries out mutual conversion between an audio band signal and IP packets; and has a function for transmitting/receiving the audio band signal and the IP packets. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a voice gateway device for converting a voice band signal transmitted and received by a private branch exchange into an IP packet communicated in an IP network.
[0002]
[Prior art]
In a company office or the like, a private branch exchange (Private Branch Exchange) is generally installed in order to efficiently exchange and connect a large number of telephone terminals and telephone lines provided in the premises of the office or the like. It is.
[0003]
For example, as shown in FIG. 7, a private branch exchange 20 is installed in a premises 100 of the business office or the like, and the telephone terminal 10 uses a premises interface 22 that matches the communication conditions and electrical characteristics of the telephone terminal 10. Connected to telephone exchange 20.
[0004]
Further, the subscriber line 4 is connected to a subscriber line exchange 80a installed by a telecommunications carrier that provides a telephone service through the public telephone line network 8, and a relay terminal which is a maintenance responsibility dissolution point with the telecommunications carrier. 3 and connected to the private branch exchange 20 using a local line interface 21 that matches the communication conditions and electrical characteristics of the subscriber line 4.
[0005]
On the other hand, with the recent progress in communication technology and the development of the Internet, the so-called IP telephone service, which has a lower communication fee than the telephone service using the public telephone network 8, has become widespread. In view of such a situation, a user using the telephone service by the public telephone network 8 using the private branch exchange 20 has requested the use of the IP telephone service.
[0006]
In order to use the IP telephone service by using the private branch exchange 20, a voice gateway device for converting a voice band signal and an IP packet between each other and an xDSL modem for realizing high-speed digital transmission using the subscriber line 4 are used. It is necessary to interpose between the private branch exchange 20 and the subscriber line 4.
[0007]
[Patent Document 1]
JP-A-2002-112370 (page 6-8, FIG. 1-2)
[0008]
[Problems to be solved by the invention]
However, conventional IP telephone service providing apparatuses such as the above-mentioned voice gateway apparatus and xDSL modem cannot connect a plurality of subscriber lines that are common in an environment using a private branch exchange, and require a private telephone exchange. There was a problem that it was not suitable for introduction into the environment in which it was used.
[0009]
Further, in order to connect such a conventional IP telephone service providing apparatus to a private branch exchange, an extension interface must be installed in the private branch exchange instead of the central office interface to which the subscriber line has been connected. In addition, there is a problem that a purchase cost of the interface is generated, and a cost associated with repair or replacement of the private telephone exchange is generated depending on the accommodation status of the line of the private telephone exchange.
[0010]
Further, the conventional IP telephone service providing apparatus can be connected to both the public telephone line network and the IP network. However, when communication is performed via the IP network, the public telephone line network is connected to the public telephone line network. When an incoming call is received through the public telephone network, it is not possible to notify the public telephone network that the incoming call cannot be exchanged and connected because communication is in progress. However, there is a problem that a ring tone (RBT) is continuously transmitted to the communication terminal. Particularly, in an environment where a private branch exchange is used, since the volume of incoming and outgoing calls is large, the frequency of occurrence of such a situation increases, which has been a serious problem.
[0011]
The present invention has been made in view of the above points, and an object of the present invention is to provide a voice gateway device for easily introducing an IP telephone service in an environment using a private branch exchange.
[0012]
[Means for Solving the Problems]
A first feature of the present invention is a voice gateway device that is inserted between a subscriber line and a private branch exchange to convert between an audio band signal transmitted and received by the private branch exchange and an IP packet. A subscriber line connecting unit for connecting a plurality of local lines connected to a private branch exchange, and an IP communication path connected to an IP network for communicating IP packets. Based on the IP network connection unit and the telephone number of the communication destination received from the private branch exchange via the local line, the voice band signal received from the private branch exchange via the local line is converted into an IP packet and converted into an IP packet. It is essential to have switching means for selecting whether to transmit the signal to a communication path or to transmit the voice band signal to a subscriber line, and switching and connecting the station line to the IP communication path or the subscriber line. And
[0013]
According to this feature, since the voice gateway device connects the plurality of subscriber lines and the office line connected to the private branch exchange, introduction of the IP telephone service in an environment using the private branch exchange can be facilitated. .
[0014]
According to this feature, the voice gateway device converts the voice band signal received from the private branch exchange via the local line into an IP packet based on the telephone number of the communication destination received from the private branch exchange via the local line. Select whether to convert and send to the IP communication path or to send the voice band signal to the subscriber line via the subscriber line connection unit, and exchange connection between the office line and the IP communication path or the subscriber line. Therefore, the public telephone line network and the IP network can be used properly according to the telephone number of the communication destination.
[0015]
A second feature of the present invention is that, when all the office lines are communicating, an incoming call to the private branch exchange is received via the subscriber line or an incoming call to the private branch exchange via the IP communication path is received. In such a case, the gist of the present invention is to have a busy notification means for notifying the communication terminal that has generated the incoming call that the incoming call cannot be switched and connected because the local line is busy.
[0016]
According to a third aspect of the present invention, in the second aspect of the present invention, when the busy notification means receives an incoming call to the private branch exchange via the subscriber line when all the office lines are communicating. Performs a predetermined operation indicating that the central office is communicating with the network that has processed the incoming call, and the network performs a predetermined operation on the communication terminal that generated the incoming call in accordance with the predetermined operation. The gist of the present invention is to transmit a busy signal to notify that the incoming call cannot be switched and connected because the local line is busy.
[0017]
According to this feature, the voice gateway device transmits a signal notifying that the office line is communicating to the network that has processed the incoming call, and the network responds to the incoming call in response to the notified signal. A communication signal is sent to the communication terminal that caused the call to notify that the incoming call cannot be switched and connected because the central office is busy, so the incoming call to the private branch exchange via the subscriber line is sent. Can be reliably notified to the communication terminal that caused the above that the response cannot be made because the office line is communicating.
[0018]
According to a fourth aspect of the present invention, in the second aspect of the present invention, the busy notification unit transmits a voice band signal indicating that the office line is communicating to the communication terminal that has generated the incoming call. The gist is to notify that the incoming call cannot be switched and connected because the line is busy.
[0019]
According to this feature, the voice gateway device transmits a voice band signal indicating that the office line is communicating to the communication terminal that has generated the incoming call, so that the incoming call is received because the office line is communicating. Since it is notified that the call cannot be switched and connected, it is possible to reliably notify the communication terminal that it cannot respond because the office line is busy.
[0020]
According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the point is that the central office connection unit is connected to the private branch exchange using an interface operating as a subscriber line.
[0021]
According to this feature, since the voice gateway device connects to the private branch exchange using the interface operating as the subscriber line side, the private branch exchange connects the subscriber line before connecting the voice gateway device. The existing interface can be continuously used, and modification or replacement of the private branch exchange can be avoided.
[0022]
According to a sixth aspect of the present invention, in the first to alternate aspects of the present invention, the office line is associated with a specific telephone number, and the exchange means is configured such that when the specific office line is communicating. When an incoming call for a telephone number associated with the station line is received, the other point is to capture another office line not used for communication and exchange-connect the incoming call.
[0023]
According to this feature, when the voice gateway apparatus receives an incoming call for the telephone number associated with the specific line while the specific line is being communicated, the voice gateway apparatus may perform another use connected to the line connection. Since the incoming call is captured and the incoming call is exchanged and connected, the incoming call can be processed efficiently.
[0024]
According to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, when the IP network has a failure, the exchange means establishes a connection between the office line and the subscriber line regardless of the telephone number of the communication destination. The point is to exchange connection.
[0025]
According to this feature, when the IP network fails, the voice gateway device switches and connects the office line and the subscriber line via the subscriber line connection unit. Telephone communication can be secured.
[0026]
According to an eighth aspect of the present invention, in the first to seventh aspects of the present invention, when the exchange means does not operate normally, a detour that enables a telephone communication by directly connecting a subscriber line and an office line. The point is to have a connection means.
[0027]
According to this feature, the voice gateway device enables telephone communication by directly connecting the subscriber line connected to the subscriber line connection unit and the office line connected to the office line connection unit. Even when a failure occurs in the gateway device, constant telephone communication can be secured.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
(Overall Configuration of Communication System Including Voice Gateway Device According to One Embodiment)
A voice gateway device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating a communication system including a voice gateway device 30 according to the present embodiment.
[0029]
As shown in the figure, the communication system including the voice gateway device 30 according to the present embodiment includes a telephone terminal 10, a private branch exchange 20, a voice gateway device 30, a call agent 40, an IP network 7, It is schematically composed of a telephone network 8.
[0030]
The telephone terminal 10 is a communication terminal capable of inputting / outputting and transmitting / receiving voice band signals, and is connected to the private branch exchange 20.
[0031]
The private branch exchange 20 has a function of connecting a plurality of telephone terminals 10 and a plurality of office lines 9 connected to the voice gateway device 30, and switching and connecting the telephone terminals 10 and the office lines 9. In the present embodiment, the private branch exchange 20 uses the FXS (Foreign Exchange Station) interface that can transmit and receive a voice band signal and a call / response signal and supply power to the telephone terminal 10, for example. Can be connected. The private branch exchange 20 can connect a line with the voice gateway device 30 using, for example, an FXO (Foreign Exchange Office) interface having signal conditions and electrical characteristics for connecting the subscriber line 4. it can.
[0032]
The voice gateway device 30 connects the local line 9 connected to the private branch exchange 20, the subscriber line 4, and the xDSL modem 1 that transmits and receives digital signals using the subscriber line 4, and connects with the voice band signal. It has a function of mutually converting IP packets and transmitting and receiving voice band signals and IP packets. In addition, the subscriber line 4 is connected to the voice gateway device 30 via the relay terminal 3 which is a maintenance responsibility disaggregation point with the communication service provider providing the subscriber line 4. The xDSL modem 1 is connected to a subscriber line 4 via a splitter 2 for separating a digital signal and a voice band signal. The xDSL modem 1 is, for example, an ITU-TG. An ADSL (Asymmetric Digital Subscriber Line) modem specified in 992.1 (G. DMT) or 992.2 (G. Lite) can be used.
[0033]
The call agent 40 has a function of converting a telephone number and an IP address and processing a telephone call in the IP network 7 in order to provide telephone communication via the IP network 7. In the present embodiment, the call agent 40 can be realized by, for example, a Media Gateway Controller (MGC) / Media Gateway Controller (MGC) defined in MGCP (Media Gateway Control Protocol). In addition, the call agent 40 is based on ITU-TH. It may be a gatekeeper specified in H.323 or a SIP server specified in Session Initiation Protocol (SIP).
[0034]
The IP network 7 is a communication network based on TCP / IP for providing an IP telephone service, and is a collective xDSL modem DSLAM5 opposed to the xDSL modem 1 connected to the splitter 2 and the voice gateway device 30. And is connected to the subscriber line 4 via.
[0035]
In the present embodiment, for example, the Internet can be used as the IP network 7. Further, the IP network 7 may be a dedicated closed network based on TCP / IP for providing an IP telephone service.
[0036]
The public telephone network 8 is a telephone network (PSTN) using a circuit switching system, and connects the subscriber lines 4 using the subscriber line switches 80a and 80b. The IP network 7 and the public telephone line network 8 are connected to each other via the inter-network connection gateways 70a and 70b and the subscriber line exchanges 80a and 80b so as to be able to communicate with each other. The inter-network connection gateways 70a and 70b and the subscriber line exchanges 80a and 80b are, for example, Nos. Specified by ITU-T. Signal information such as telephone numbers can be transmitted and received using the 7 common line signaling system.
[0037]
In the communication system including the voice gateway device 30 according to the embodiment as described above, the telephone terminal 10 communicates with the telephone terminal 60 that subscribes to the IP telephone service by the IP network 7 via the IP network 7 and the public telephone. Telephone communication with a general subscriber telephone terminal 90 connected to the line network 8 can be performed via the private branch exchange 20.
[0038]
Further, the telephone terminal 60 is connected to the IP network 7 via the VoIP adapter 50, the xDSL modem 1, and the splitter 2, which execute a process of converting a voice band signal into an IP packet and inquiring the call agent 40 of an IP address. .
[0039]
Next, the configuration of the voice gateway device 30 according to the present embodiment will be described with reference to FIG. As shown in the figure, the voice gateway device 30 includes a subscriber line connection unit 31, a local line connection unit 32, an IP network connection unit 33, a VoIP conversion unit 34, a connection control unit 35, a voice response unit 36, a storage unit 37, and an external interface unit 38.
[0040]
The subscriber line connection unit 31 includes an interface that satisfies signal conditions and electrical characteristics for connecting the subscriber lines 4, and connects a plurality of subscriber lines 4. In the present embodiment, the subscriber line connection unit 31 satisfies signal conditions and electrical characteristics for connecting to the subscriber line exchanges 80a and 80b via a subscriber line constituted by, for example, a telephone copper cable. An FXO interface, which is a two-wire interface, can be implemented.
[0041]
The number of subscriber lines 4 to which the subscriber line connection unit 31 can be connected may be changed according to the scale of the private branch exchange 20 connected to the voice gateway device 30. Further, the subscriber line connection unit 31 is interposed between the subscriber line 4 and the subscriber line switch 80a, with respect to signal conditions and electrical characteristics of the subscriber line switch 80a connected via the subscriber line 4. For example, a 4-wire interface may be mounted according to the configuration of the communication equipment.
[0042]
The office line connection unit 32 includes an interface that satisfies signal conditions and electrical characteristics for connecting the office line 9 connected to the private branch exchange 20, and connects a plurality of office lines 9. In the present embodiment, the office line connecting unit 32 can mount an interface having signal conditions and electrical characteristics connectable to, for example, an FXO interface mounted on the private branch exchange 20.
[0043]
The office line connection unit 32 mounts an interface having signal conditions and electrical characteristics connectable to the FXO interface mounted on the private branch exchange 20 so that the private branch exchange 20 can connect with the voice gateway device 30 before connecting. The FXO interface to which the subscriber line 4 was connected can be used continuously.
[0044]
The number of office lines 9 to which the office line connection unit 32 can be connected may be changed according to the scale of the private branch exchange 20 connected to the voice gateway device 30.
[0045]
In the present embodiment, the IP network connection unit 33 connects the IP communication path 6 that enables communication using the TCP / IP protocol group via the IP network 7.
[0046]
More specifically, the IP network connection unit 33 includes an interface capable of LAN communication, and transmits and receives IP packets to and from devices capable of LAN communication. For example, the 10BASE-T defined in IEEE802.3 And 100BASE-TX defined in 802.3u.
[0047]
The IP network connection unit 33 according to the present embodiment is connected to the xDSL modem 1, and is connected to the IP network 7 via the DSLAM 5 and the subscriber line 4 formed by the splitter 2 and the telephone copper cable.
[0048]
Although the IP network connection unit 33 according to the present embodiment is connected to the xDSL modem 1, it is connected to the IP network 7 via a subscriber line composed of an optical fiber using a media converter or the like. Is also good.
[0049]
The VoIP conversion unit 34 converts a voice band signal transmitted and received by the central office connection unit 32 and an IP packet transmitted and received by the IP network connection unit 33 from each other, and also allows the IP packet to pass through the IP network 7. A necessary header or the like is added.
[0050]
In the present embodiment, the VoIP conversion unit 34 is, for example, an ITU-TG. 811 or 8 Gbit / sec. 729 Annex-A can be used to digitize a voice band signal, and the digitized voice band signal can be converted into an IP packet. Further, the VoIP conversion unit 34 can add a UDP or TCP header or an RTP (Real-time Transport Protocol) header according to the content of the IP packet.
[0051]
The connection control unit 35 converts the voice band signal received via the local line 9 into an IP packet based on the telephone number of the communication destination received from the private branch exchange 20 via the local line 9 by the VoIP conversion unit 34. The user selects whether to convert the data and send it to the IP network connection unit 33 or to the subscriber line connection unit 31. Further, the connection control unit 35 has a function of switching and connecting the office line 9 with the IP communication path 6 or the subscriber line 4 based on the selection result.
[0052]
Further, the connection control unit 35 converts the IP packet received via the IP network connection unit 33 into a voice band signal by the VoIP conversion unit 34 and sends it out to the office line 9 and via the subscriber line connection unit 31 It has a function of transmitting a voice band signal received from the subscriber line 4 to the local line 9.
[0053]
Specifically, the connection control unit 35 determines whether the subscriber line 4 is connected to the office line 9 and the IP network connection unit 33 or the subscriber line connection unit 31 based on the telephone number information registered in the storage unit 37. And exchange connection.
[0054]
As described above, since the connection control unit 35 determines the exchange connection destination based on the telephone number information stored in the storage unit 37, the user of the telephone terminal 10 needs to connect via the IP network 7 or the public telephone line network 8. The telephone service provided by the IP network 7 or the public telephone network 8 can be properly used without being conscious of the telephone communication selection. Further, when a telephone number for which communication is not permitted is stored in the storage unit 37, the connection control unit 35 can also control the transmission of the telephone number.
[0055]
In addition, when the office line 9 is associated with a specific telephone number, the connection control unit 35 performs an incoming call for the telephone number associated with the office line 9 when a certain office line 9 is in communication. Is received, another station line 9 not used for communication is captured to exchange and connect the incoming call.
[0056]
For example, in FIG. 3, the office line 9a associated with “telephone number: 1234-1111” and the office line 9b associated with “telephone number: 1234-1112” are exchanged and connected by the connection control unit 35 to perform communication. In this state, the case where an incoming call addressed to "telephone number: 1234-1111" is further received is shown. The connection control unit 35 recognizes that the office line 9a associated with “telephone number: 1234-1111” is already communicating, and is associated with “telephone number: 1234-1113” not used for communication. The subscriber line 4 that has received the incoming call can be exchanged with the local line 9c by using the local line 9c.
[0057]
Further, in the present embodiment, when switching connection between the office line 9 and the IP communication path 6, the connection control unit 35 calls the IP address corresponding to the telephone number of the communication destination received via the office line 9. It can be obtained from the agent 40.
[0058]
Further, in the present embodiment, when the IP network 7 has a failure, the connection control unit 35 connects the local line 9 and the subscriber line 4 irrespective of the telephone number of the communication destination received via the local line 9. The exchange can be connected. The connection control unit 35 can determine a failure in the IP network 7 when, for example, communication with the call agent 40 cannot be established.
[0059]
In this embodiment, the VoIP conversion unit 34 and the connection control unit 35 constitute an exchange unit.
[0060]
Further, in this embodiment, when an incoming call to the private branch exchange 20 via the subscriber line 4 is received while all the office lines 9 are communicating in the present embodiment, the connection control unit 35 processes the incoming call. Performs an operation indicating that the station line 9 is communicating, and the network transmits a busy signal to the communication terminal that generated the incoming call in response to the operation, whereby the station It can be notified that the incoming call cannot be switched because the line 9 is busy. In the present embodiment, the connection control unit 35 constitutes a busy notification unit.
[0061]
When all of the office lines 9 are communicating, the connection control unit 35 is connected to the private line switching unit via another subscriber line 4 (idle state) which is not used for communication connected to the subscriber line connection unit 31. When an incoming call to the telephone set 20 is received, for example, a connection operation used in a number information transmission function (dial-in) or an outgoing telephone number reception function (number display), which is an additional service of the telephone service provided by the public telephone line network 8 Using the sequence, it is possible to indicate to the local exchanges 80a and 80b connected to the public telephone network 8 that the central office 9 is communicating.
[0062]
Specifically, the connection control unit 35 uses the connection operation sequence used in the number information sending function or the outgoing telephone number receiving function to call a signal (IR or the like) from the subscriber line exchanges 80a, 80b. After returning a primary response signal (DC loop) to the information receiving terminal activation signal (CAR), after a predetermined time has elapsed, the loop of the subscriber line 4 that has received the incoming call is released.
[0063]
When the connection control unit 35 releases the loop of the subscriber line 4 that has received the incoming call, the subscriber line exchanges 80a and 80b recognize that the central office 9 is communicating and communicate with the private telephone exchange 20. A busy tone (BT) can be transmitted to a communication terminal such as a telephone terminal that has generated the incoming call.
[0064]
Further, the connection control unit 35 transmits a voice band signal indicating that the station line 9 is communicating to the communication terminal that has generated the incoming call, so that the station line 9 is communicating. It notifies that incoming calls cannot be switched.
[0065]
Specifically, in the present embodiment, when the incoming call to the private branch exchange 20 via the subscriber line 4 is received while all the office lines 9 are communicating, in this embodiment, the connection control unit 35 By responding and transmitting the talk key stored in the voice response unit 36 to the communication terminal that has generated the incoming call, it is possible to notify that the central office 9 is communicating. Accordingly, even when the additional service such as the above-described number information transmission function and calling telephone number reception function is not used, the connection control unit 35 keeps the station line 9 in communication with the communication terminal that has generated the incoming call. It can be surely notified.
[0066]
Further, even when an incoming call to the private branch exchange 20 is received via the IP communication path 6, the connection control unit 35 responds to the incoming call and sends a voice response to the communication terminal that has generated the incoming call. The talk key stored in 36 may be transmitted.
[0067]
Further, in the present embodiment, when an incoming call to the private branch exchange 20 is received via the IP network connection unit 33 while all the office lines 9 are communicating, in this embodiment, the connection agent 35 A signal notifying that the office line 9 is communicating can be transmitted. Based on the notification from the connection control unit 35, the call agent 40 confirms that the telephone number transmitted by the communication terminal is communicating with the VoIP adapter 50 to which the communication terminal that generated the incoming call is connected. Can be notified.
[0068]
In the present embodiment, if the function of switching and connecting the office line 9 to the IP communication path 6 or the subscriber line 4 does not operate normally, the connection control unit 35 will connect the subscriber line 4 to the office line 4. 9 is directly connected to the detour connection means for enabling telephone communication.
[0069]
Specifically, the connection control unit 35 connects the subscriber line 4 to the office line 9 when the function of the exchange connection does not operate normally due to, for example, a failure in the power supply or the like supplied to the voice gateway device 30. The connection can be performed so that the voice band signal can be communicated therebetween, so that the exchange connection function of the connection control unit 35 is not interposed.
[0070]
The voice response unit 36 sends out a talk key indicating that the station line 9 is communicating in response to an instruction from the connection control unit 35.
[0071]
The voice response unit 36 according to the present embodiment can store a voice message such as “the telephone is busy at the moment…” and can transmit the voice message in response to an instruction from the connection control unit 35. The voice response unit 36 stores an arbitrary voice message input using the telephone terminal 10 in the voice response unit 36 and sends out the stored voice message in accordance with an instruction from the connection control unit 35. You can also.
[0072]
While the voice response unit 36 is transmitting a talkie indicating that the line 9 is communicating to a communication terminal such as a telephone terminal that has generated an incoming call to the private branch exchange 20, When the communication using the line 9 is completed, the connection control unit 35 can switch and connect the incoming call using the local line 9.
[0073]
The storage unit 37 stores a telephone number of a communication destination to perform telephone communication via the IP network 7 or the public telephone network 8.
[0074]
In the present embodiment, the storage unit 37 can store a telephone number to be used for telephone communication via the public telephone network 8 and a telephone number for which communication is not permitted. The storage unit 37 can store an arbitrary telephone number or a block of telephone numbers such as, for example, an area code + a city code + a subscriber number, an area code + a city code, an area code, and a country code. It should be noted that a specific identifier is given to a telephone number for which communication is not permitted, so that the connection control unit 35 can make a determination at the time of exchange connection.
[0075]
Further, the storage unit 37 can temporarily store an IP address or the like received from the call agent 40 and associated with the telephone number of the communication destination.
[0076]
The external interface unit 38 provides a communication interface for connecting an external device in order to register a telephone number in the storage unit 37 and make settings for the voice gateway device 30.
[0077]
In the present embodiment, the external interface unit 38 has, for example, an RS-232C interface, and can connect a PC or the like. The registration of the telephone number in the storage unit 37 and the setting in the voice gateway device 30 can be performed by a PC or the like connected to the external interface unit 38.
[0078]
(Operation of the communication system described above)
The operation of the above-described communication system will be described with reference to FIGS.
[0079]
FIG. 4 is a communication sequence diagram when the telephone terminal 10 makes a call to the telephone terminal 60 in the communication system according to the present embodiment.
[0080]
When the telephone number given to the telephone terminal 60 is input from the telephone terminal 10, the input telephone number is transmitted from the telephone terminal 10 to the private branch exchange 20 (S401).
[0081]
The private branch exchange 20 exchanges and connects the telephone terminal 10 with the office line 9, and sends the telephone number received from the telephone terminal 10 to the voice gateway device 30 (S403).
[0082]
The voice gateway device 30 determines that the telephone number received from the private branch exchange 20 should communicate via the IP network 7 based on the telephone number information stored in the voice gateway device 30, An inquiry is made to the call agent 40 for the corresponding IP address (S405).
[0083]
The call agent 40 notifies the VoIP adapter 50 connected to the telephone terminal 60 of the incoming call (S407).
[0084]
The VoIP adapter 50 recognizes the incoming call from the call agent 40, inverts the polarity of the line with the telephone terminal 60, and sends a calling signal to the telephone terminal 60 (S409).
[0085]
When the receiver of the telephone terminal 60 is lifted (off-hook), the telephone terminal 60 loops the line with the VoIP adapter 50 and responds to the call from the call agent 40 (S411).
[0086]
The VoIP adapter 50 notifies the port number used for the communication connection with the voice gateway device 30 and the call agent 40 that the telephone terminal 60 has responded (S413).
[0087]
The call agent 40 notifies the voice gateway device 30 of the IP address assigned to the VoIP adapter 50 and the port number notified from the VoIP adapter 50 (S415).
[0088]
The voice gateway device 30 requests the VoIP adapter 50 to set up a communication connection based on the IP address given to the VoIP adapter 50 notified from the call agent 40 and the port number used for the communication connection (S417). ).
[0089]
The VoIP adapter 50 sets a communication connection in response to a request for setting a communication connection from the voice gateway device 30 (S419).
[0090]
The voice gateway device 30 exchanges and connects the communication connection set in steps S417 and S419 with the office line 9 that has received the telephone number assigned to the telephone terminal 60 in step S403 (S421).
[0091]
Further, the VoIP adapter 50 connects the telephone terminal 60 so as to be able to communicate using the communication connection set in steps S417 and S419 (S423).
[0092]
Completion of the processing of step S421 and step S423 starts communication between the telephone terminal 10 and the telephone terminal 60 (S425).
[0093]
FIG. 5 is a communication sequence diagram when the telephone terminal 10 makes a call to the general subscriber telephone terminal 90 in the communication system according to the present embodiment.
[0094]
When the telephone number assigned to the general subscriber telephone terminal 90 is input from the telephone terminal 10, the input telephone number is transmitted from the telephone terminal 10 to the private branch exchange 20 (S501).
[0095]
The private branch exchange 20 exchanges and connects the telephone terminal 10 with the office line 9 connected to the voice gateway device 30, and sends the telephone number received from the telephone terminal 10 to the voice gateway device 30 (S503).
[0096]
The voice gateway device 30 determines that the telephone number received from the private branch exchange 20 should communicate via the IP network 7 based on the telephone number information stored in the voice gateway device 30, An inquiry is made to the call agent 40 for the corresponding IP address (S505). If the telephone number received from the private branch exchange 20 is to be communicated via the public telephone line network 8, the voice gateway device 30 sends the telephone number to the subscriber line exchange 80a. Is sent.
[0097]
The call agent 40 recognizes that the telephone number received from the voice gateway device 30 is a general subscriber telephone terminal that subscribes to the telephone service provided by the public telephone network 8, and transmits the telephone number to the internetwork connection gateway 70b. The transfer is performed (S507).
[0098]
The internetwork connection gateway 70b notifies the subscriber line exchange 80b of the telephone number transferred from the call agent 40 by a common line signal (S509).
[0099]
The local exchange 80b inverts the polarity of the line with the general subscriber telephone terminal 90 based on the telephone number notified from the internetwork connection gateway 70b, and sends a calling signal to the general subscriber telephone terminal 90 ( S511).
[0100]
When the receiver of the general subscriber telephone terminal 90 is lifted (off-hook), the general subscriber telephone terminal 90 loops the line with the local exchange 80b and responds to a call from the local exchange 80b (S513).
[0101]
The local exchange 80b notifies the inter-network connection gateway 70b by a common line signal that the general subscriber telephone terminal 90 has answered the call (S515).
[0102]
When notified from the local exchange 80b that the general subscriber telephone terminal 90 has answered the call, the internetwork connection gateway 70b notifies the call agent 40 of the port number used for the communication connection with the voice gateway device 30. Is notified (S517).
[0103]
The call agent 40 notifies the voice gateway device 30 of the IP address assigned to the internetwork connection gateway 70b and the port number notified from the internetwork connection gateway 70b (S519).
[0104]
The voice gateway device 30 sets the communication connection to the internet connection gateway 70b based on the IP address given to the internet connection gateway 70b notified from the call agent 40 and the port number used for the communication connection. Request (S521).
[0105]
The network connection gateway 70b sets a communication connection in response to a request for setting a communication connection from the voice gateway device 30 (S523).
[0106]
The voice gateway device 30 exchanges and connects the communication connection set in steps S521 and S523 with the station line 9 that has received the telephone number assigned to the general subscriber telephone terminal 90 in step S503 (S525).
[0107]
The internetwork connection gateway 70b uses the communication connection set in steps S521 and S523 to communicably connect the general subscriber telephone terminal 90 via the subscriber line exchange 80b (S527).
[0108]
Completion of the processing of steps S525 and S527 starts communication between the telephone terminal 10 and the general subscriber telephone terminal 90 (S529).
[0109]
Next, an operation of processing an incoming call to the voice gateway device 30 according to the present embodiment will be described with reference to FIG.
[0110]
The voice gateway device 30 receives an incoming call from the IP network 7 or the public telephone network 8 (S601).
[0111]
The voice gateway device 30 checks whether there is a station line 9 not used for communication (S603).
[0112]
If there is a station line 9 not used for communication, the voice gateway device 30 exchanges and connects the station line 9 with the subscriber line 4 or the IP communication path 6 that has received the incoming call (S605).
[0113]
When all the office lines 9 are communicating, the voice gateway device 30 determines whether the call is an incoming call from the IP network 7 or the public telephone network 8 (S607).
[0114]
In the case of an incoming call from the IP network 7, the voice gateway device 30 transmits a signal to the call agent 40 notifying that the incoming call cannot be exchanged and connected because all the office lines 9 are communicating. S609).
[0115]
By notifying the call agent 40 that the incoming call cannot be switched and connected, the voice gateway device 30 transmits the call agent 40 to the VoIP adapter 50 to which the communication terminal that has generated the incoming call is connected. It is possible to notify that the telephone number transmitted by the communication terminal is communicating.
[0116]
Next, in the case of an incoming call from the public telephone network 8, the voice gateway device 30 returns a primary response signal (DC loop) to the subscriber line 4 that has received the incoming call (S611).
[0117]
Here, the voice gateway device 30 executes different operations depending on whether the number information sending function (dial-in) or the calling telephone number receiving function (number display) is used (S613).
[0118]
If the number information sending function or the outgoing telephone number receiving function is not used, the voice gateway device 30 responds to the incoming call and establishes a communication path with the communication terminal that generated the incoming call (S615). .
[0119]
Using the communication path established in step S615, the voice gateway device 30 transmits a voice message to the effect that the connection cannot be established because all the office lines 9 are in communication to the communication terminal that has generated the incoming call (S617). ).
[0120]
When the number information sending function or the outgoing telephone number receiving function is used, the voice gateway device 30 returns the primary response signal after a predetermined time has elapsed from returning the primary response signal in step S611. The generated loop of the subscriber line 4 is released (S619).
[0121]
When the voice gateway device 30 performs the operation of step S619, the subscriber line switch 80a connected to the subscriber line 4 is connected to the local line 9 because all the office lines 9 connected to the voice gateway device 30 are communicating. By recognizing that the incoming call cannot be exchanged and connected, a busy tone (BT) can be transmitted to the communication terminal that has generated the incoming call.
[0122]
(Operations and effects of the voice gateway device according to the present embodiment)
According to the voice gateway device 30 according to the present embodiment, since the voice gateway device 30 connects the plurality of subscriber lines 4 and the office line 9, the number of necessary voice gateway devices 30 is reduced, and the installation space is reduced. And the introduction work of the voice gateway device 30 can be facilitated.
[0123]
In addition, according to the voice gateway device 30 according to the present embodiment, since the line connection unit 32 mounts an interface having signal conditions and electrical characteristics connectable to the FXO interface mounted on the private branch exchange 20, The FXO interface to which the subscriber line 4 was connected before the private branch exchange 20 connected the voice gateway device 30 can be continuously used. By using such a voice gateway device 30, it is possible to use the IP telephone service at a low introduction cost while avoiding an additional cost for the private branch exchange 20, thereby contributing to the expansion of use of the IP telephone service. .
[0124]
Further, according to the voice gateway device 30 according to the present embodiment, since the connection control unit 35 determines the exchange connection destination based on the telephone number information stored in the storage unit 37, the user of the telephone terminal 10 It is possible to selectively use the telephone service provided by the IP network 7 or the public telephone network 8 without being conscious of the selection of the telephone communication via the IP network 7 or the public telephone network 8, and to reduce the communication fee. Can be used with priority.
[0125]
Further, according to the voice gateway device 30 according to the present embodiment, the connection control unit 35 is not used for communication connected to the subscriber line connection unit 31 when all the office lines 9 are communicating (idle). When an incoming call to the private branch exchange 20 is received via the other subscriber line 4 (in a state), the public telephone network 8 is utilized by using the additional service of the telephone service provided by the public telephone network 8. Can be indicated that the station line 9 is communicating. Thus, even when an incoming call to the private branch exchange 20 is received via the subscriber line 4 while all the office lines 9 are communicating, the public telephone line network 8 keeps the telephone terminal that has generated the incoming call. It is possible to reliably notify the communication terminal such as that the incoming call cannot be answered because the office line 9 is communicating.
[0126]
Further, according to the voice gateway device 30 according to the present embodiment, the connection control unit 35 transmits a talk key stored in the voice response unit 36 to a communication terminal such as a telephone terminal that has generated an incoming call to the private branch exchange 20. Thus, it can be notified that the station line 9 is communicating. As a result, even when the additional services such as the number information transmission function and the outgoing telephone number reception function are not used, the voice gateway device 30 transmits the line 9 to the communication terminal such as the telephone terminal that has generated the incoming call. Can be reliably notified that the incoming call cannot be answered due to communication.
[0127]
Further, according to the voice gateway device 30 according to the present embodiment, when the IP network 7 has a failure, the connection control unit 35 sets the telephone number of the communication destination received from the private branch exchange 20 via the line 9 Regardless, the station line 9 is switched and connected to the subscriber line 4 via the subscriber line connection unit 31.
[0128]
Furthermore, according to the voice gateway device 30 according to the present embodiment, when the function of switching and connecting the office line 9 with the IP communication path 6 or the subscriber line 4 does not operate normally, the connection control unit 35 The telephone line is enabled by directly connecting the subscriber line 4 and the office line 9.
[0129]
As a result, the voice gateway device 30 according to the present embodiment can provide telephone communication via the public telephone line network 8 via the subscriber line 4 even in the case of a failure in the IP network 7, the connection control unit 35, or the like. As a result, the operation rate of the voice gateway device 30 can be improved.
[0130]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a voice gateway device for easily introducing an IP telephone service in an environment using a private branch exchange.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a communication system including a voice gateway device according to an embodiment of the present invention.
FIG. 2 is a functional block diagram of a voice gateway device according to an embodiment of the present invention.
FIG. 3 is a connection operation diagram of the voice gateway device according to the embodiment of the present invention.
FIG. 4 is a communication sequence diagram of a communication system including a voice gateway device according to an embodiment of the present invention.
FIG. 5 is a communication sequence diagram of a communication system including a voice gateway device according to an embodiment of the present invention.
FIG. 6 is an operation flowchart of a communication system including a voice gateway device according to an embodiment of the present invention.
FIG. 7 is a schematic configuration diagram of a communication system including a conventional private branch exchange.
[Explanation of symbols]
1 xDSL modem, 2 splitter, 3 relay terminal, 4 subscriber line, 5 DSLAM, 6 IP communication path, 7 IP network, 8 public telephone network, 9 office line, 10 telephone Terminals 20 Private branch exchanges 30 Voice gateway devices 40 Call agents 50 VoIP adapters 60 Telephone terminals 70 a and 70 b Inter-network connection gateways 80 a and 80 b Subscriber line exchanges 90 General Subscription telephone terminal

Claims (8)

A voice gateway device inserted between a subscriber line and a private branch exchange to convert between a voice band signal transmitted and received by the private branch exchange and an IP packet,
A subscriber line connection unit for connecting the plurality of subscriber lines,
An office line connection unit for connecting a plurality of office lines connected to the private branch exchange;
An IP network connection unit that connects an IP communication path connected to an IP network that communicates the IP packet;
A voice band signal received from the private branch exchange via the local line is converted into the IP packet based on a telephone number of a communication destination received from the private branch exchange via the local line, and the IP communication path is converted. Switching means for selecting whether to transmit the voice band signal to the subscriber line or switching the office line to the IP communication path or the subscriber line. Voice gateway device. When all the office lines are communicating, when an incoming call to the private branch exchange is received through the subscriber line or when an incoming call to the private branch exchange is received through the IP communication path, 2. The voice according to claim 1, further comprising a busy notification unit for notifying a communication terminal that has generated the incoming call that the incoming call cannot be switched and connected because the local line is busy. Gateway device. The busy notification unit, when receiving an incoming call to the private branch exchange via the subscriber line while all the office lines are communicating, sends the incoming call to the network that has processed the incoming call. Perform a predetermined operation indicating that the line is communicating,
The network transmits a busy signal to the communication terminal that has generated the incoming call in accordance with the predetermined operation, so that the incoming call cannot be switched and connected because the central office is busy. The voice gateway device according to claim 2, wherein the notification is performed. The busy notification unit transmits a voice band signal indicating that the office line is communicating to the communication terminal that has generated the incoming call, so that the incoming call is received because the office line is communicating. 3. The voice gateway device according to claim 2, wherein notification is made that a call cannot be switched and connected. The voice gateway device according to any one of claims 1 to 4, wherein the office line connection unit connects to the private branch exchange using an interface that operates as the subscriber line. The office line is associated with a specific telephone number, and the exchange unit receives an incoming call for the telephone number associated with the office line while the specific office line is communicating. The voice gateway device according to any one of claims 1 to 5, wherein the voice gateway device captures the other office line not used for communication and exchanges the incoming call. 7. The communication system according to claim 1, wherein said switching means exchanges and connects said office line and said subscriber line regardless of said telephone number of said communication destination when said IP network has a failure. The voice gateway device according to claim 1. 8. A device according to claim 1, further comprising a bypass connection means for directly connecting said subscriber line and said office line to enable telephone communication when said switching means does not operate normally. The voice gateway device according to the paragraph.

Images