Smartphone extension telephone system

Abstract

To provide a telephone system which can stably connect an external telephone terminal to an existing telephone system as a virtual extension terminal with a very inexpensive configuration and can utilize many functions of an internal telephone system such as an outside line hold.SOLUTION: In a telephone system 100, an external telephone terminal includes an external telephone terminal connection control unit for connecting to a voice server via the Internet network, and the voice server includes a voice server connection control unit for connecting to the external telephone terminal via the Internet network, and the external telephone terminal control unit and the voice server connection control unit establish a two-way constant connection by constantly transmitting and receiving IP address information in both directions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a telephone control technology that can connect an external telephone terminal to an existing in-building telephone system as a virtual extension terminal via the Internet.

Background Art

[0002] Conventionally, telephone systems for using external telephone terminals such as smartphones and tablets as in-building extension terminals are known. For example, Patent Document 1 discloses a telephone control device that interconnects extension terminals, and an in-building hub that connects an external telephone terminal to a remote desktop server via the Internet and relays call control messages, and a telephone system that uses the external telephone terminal as a virtual extension terminal by exchanging the call control messages.

[0003] Patent Document 2 discloses a telephone system having an in-building exchange system that constructs an in-building telephone network, and a gateway device that is connected to the in-building telephone system and is connected to an external telephone terminal assigned a portable extension number via the Internet network.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the invention of Patent Document 1, since an in-building hub is provided to relay call control messages, there is a problem that if the connection with the external telephone terminal as a client becomes unstable, the communication between the external and the in-building telephone system ends, and a reconnection operation must be performed again.

[0006] In the invention of Patent Document 2, from the viewpoint of security, the in-building telephone system and an external telephone terminal outside communicate with each other through a telephone line network, so there is a problem that the telephone charges increase.

[0007] The present invention has been made in view of the above problems, and with a very inexpensive configuration, it is possible to stably connect an external telephone terminal as a virtual extension terminal to an existing telephone system, and to provide a telephone system that can utilize many functions of the in-building telephone system such as call holding.

Means for Solving the Problems

[0008] In order to achieve the above object, the present invention includes the following inventions. [Invention 1] At least one extension telephone device assigned with an in-building extension number, An in-building telephone exchange device that exchanges and connects the extension telephone device to the in-building telephone network and interconnects the extension telephone devices by transmitting and receiving call control messages to and from the extension telephone device via the in-building telephone network, A telephone system comprising a voice server connected to the in-building telephone exchange device via an in-building network and connected to an external telephone terminal via the Internet network, The external telephone terminal includes a connection control unit for the external telephone terminal for connecting to the voice server via the Internet network, The voice server includes a connection control unit for the voice server for connecting to the external telephone terminal via the Internet network, The connection control unit for the external telephone terminal encrypts the voice packet into an encrypted voice packet and reconstructs the encrypted voice packet transmitted from the voice server into a voice packet, The connection control unit for the voice server encrypts the voice packet transmitted from the in-building telephone exchange device into an encrypted voice packet and transmits it to the external telephone terminal, and reconstructs the encrypted voice packet transmitted from the external telephone terminal into a voice packet and transmits the voice packet to the in-building telephone exchange device, A telephone system characterized in that a control unit for an external telephone terminal and a connection control unit for a voice server always establish a two-way permanent connection by always transmitting and receiving IP address information bidirectionally. [Invention 2] The voice server is assigned a unique IP address for external telephones and a unique IP address for the in-house network. The telephone system according to Invention 1, characterized in that the external telephone terminal is assigned a unique IP address for external telephones and an extension number for in-house use. [Invention 3] The telephone system according to Invention 1 or 2, characterized in that the two-way permanent connection between the connection control unit for the external telephone terminal and the connection control unit for the voice server is a VPN connection. [Invention 4] The telephone system according to Invention 3, characterized in that the connection control unit for the external telephone terminal transmits only voice packets as encrypted voice packets to the voice server. [Advantages of the Invention]

[0009] According to the present invention, by connecting a voice server to the in-house telephone exchange device of an existing in-house telephone system, it is possible to convert a voice signal from the in-house extension telephone network into an encrypted voice packet and transmit it to an external telephone terminal, and to reconstruct the encrypted voice packet from the external telephone terminal into a voice packet and transmit it to the in-house telephone exchange device to communicate with the in-house extension telephone. Therefore, the external telephone terminal can be used in the same way as an in-house extension telephone. Furthermore, since the external telephone terminal and the voice server are in a two-way permanent connection, it is possible to always wait for a voice call.

[0010] Also, since the connection control units of the external telephone terminal and the voice server perform a two-way permanent connection via a VPN connection, voice packets can be securely exchanged because they pass through a secure VPN tunnel (encrypted communication). Therefore, voice calls cannot be wiretapped, and high security is obtained.

[0011] Furthermore, since the external telephone terminal has its own extension number for the premises, the external telephone terminal can also use functions similar to those of the in-house telephone system, such as call waiting and extension calls, on the external telephone terminal.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the telephone system according to the present invention will be described with reference to FIGS. 1 to 3. However, the present invention is not intended to be limited to the configurations described below. Various changes that can be understood by those skilled in the art within the scope of the telephone system 100 of the present invention can be made to the configuration and details of the present invention. FIG. 1 is a block diagram showing the configuration of a telephone system 100 according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a voice server and an external telephone terminal according to an embodiment of the present invention. FIG. 3 is an operation flowchart showing the incoming and outgoing call operations of a telephone system 100 according to an embodiment of the present invention.

[0014] [Telephone System] The configuration of the telephone system 100 of the present invention will be described in detail with reference to FIGS. 1 and 2. The telephone system 100 mainly includes an in-house telephone exchange device 10, an extension telephone device 20, a router 40, and a voice server 50. In the telephone system 100, the extension telephone device 20 is connected to the in-building telephone exchange device 10 via an in-building telephone network, and the in-building telephone exchange device 10 is connected to the carrier telephone network 31 and is connected to the voice server 50 via the router 40 in the in-building network. The external telephone terminal 60 is connected to the voice server 50 via the Internet network 32.

[0015] In this embodiment, a voice server 50 connected to the external telephone terminal 60 via the Internet network 32 using the IP packet protocol is provided. The voice server 50 transfers voice packets between the in-building telephone exchange device 10 and the external telephone terminal 60, enabling the exchange of voice data between the external telephone terminal 60 and the extension telephone device. As a result, the external telephone terminal 60 is configured to be connected to the in-building telephone exchange device 10 as a virtual extension telephone device.

[0016] (In-building telephone exchange device) The in-building telephone exchange device 10 is assigned a dedicated outside line telephone number unique to the in-building telephone exchange device under a contract with a telecommunications carrier (hereinafter referred to as a carrier). The in-building telephone exchange device 10 controls incoming and outgoing calls to / from the outside for each of the extension telephone devices 20 via the in-building telephone network. The extension telephone device 20 uses the outside line telephone number to make telephone calls to the outside. Also, the in-building telephone exchange device 10 interconnects the extension telephone devices 20 via the in-building telephone network.

[0017] The in-building telephone exchange device 10 is, for example, a PBX (Private Branch eXchange), functions as a SIP (Session Initiation Protocol) server, and exchanges call control messages with the in-building telephone device 20 via the in-building telephone network. Thereby, the in-building telephone exchange device 10 has a function of exchange-connecting the in-building telephone device 20 and the external telephone terminal 60 recognized as a virtual in-building telephone device by the telephone system of the present invention to the carrier telephone network 31, and a function of interconnecting the virtual in-building telephone device and the in-building telephone device 20. The in-building telephone exchange device 10 recognizes and controls the in-building telephone device 20 and the external telephone terminal 60 recognized as a virtual in-building telephone device by the telephone system 100 of the present invention as the same in-building telephone device.

[0018] (Router) The router 40 is a device for connecting to the Internet, such as an optical network unit (ONU) for example, is connected to the voice server 50, and plays a role of relaying data communication between the voice server 50 and the in-building network. The router 40 is also connected to communication network lines existing in other departments not shown in FIG. 1, and is connected so as to be able to mutually transfer various packets. The WAN-side IP address of the router 40 can be connected in any method, whether variable or fixed.

[0019] (In-building telephone device) The in-building telephone device 20 is, for example, a general multifunctional telephone, and performs call control operations of the in-building telephone device 20 by exchanging call control messages with the in-building telephone exchange device 10 via the in-building telephone network. Further, the in-building telephone device 20 exchanges call control messages with other in-building telephone devices 20 connected to the in-building telephone network and external telephone communications connected to the carrier telephone network 31 via the in-building telephone exchange device 10. The in-building telephone device 20 is not particularly limited as long as it can be used as an in-building telephone, but in addition to general business phones and IP telephone devices, it may also be a softphone used in a personal computer or the like.

[0020] (Voice server) The voice server 50 is assigned a unique IP address for the in-house network and an IP address for external calls, and is configured to be able to communicate with the in-house telephone exchange device 10 via the in-house network and with the external telephone terminal 60 via the Internet network 32, and has a function of transferring communication from the in-house telephone exchange device 10 and communication from the external telephone terminal 60. The voice server 50 includes a connection control unit 51 for the voice server for connecting to the external telephone terminal 60 via the Internet network 32.

[0021] The connection control unit 51 for the voice server encrypts the voice packets sent from the in-house telephone exchange device 10, decrypts the encrypted voice packets sent from the external telephone terminal 60, and reconstructs them into voice packets. In the voice server 50, the respective IP addresses and extension numbers of the external telephone terminals 60 are associated in advance, and the encrypted voice packets are configured to be sent to the correct external telephone terminal 60. Further, the connection control unit 51 for the voice server has a filtering function for determining whether the encrypted voice packets sent from the outside are correct. As a result, the connection control unit 51 for the voice server can transmit only correct voice packets to the in-house network via the in-house network transmission unit 52, and it is possible to ensure a high level of security.

[0022] (External telephone terminal) The external telephone terminal 60 consists of information communication terminals such as mobile communication terminals such as smartphones and tablets having an IP telephone function, and PC terminals equipped with softphones, and mainly includes an external telephone terminal connection control unit 61 and a call control unit 62.

[0023] The connection control unit 61 for external telephone terminals has a function of performing voice data communication with the connection control unit 51 for voice servers of the telephone system 100 via the Internet network 32. The connection control unit 61 for external telephone terminals encrypts the voice packets transmitted from the call control unit 62 and transmits them to the voice server 50 via the Internet network 32, and decrypts the encrypted voice packets sent from the voice server 50 and reconstructs them into voice packets, and is configured to deliver them to the call control unit 62. In the control unit 61 for external telephone terminals, only voice packets are encrypted, and communication packets other than voice packets are configured to be directly transmitted to the communication network of the public carrier. That is, only voice calls are transmitted to the voice server 50. As a result, the load on the voice server 50 is significantly reduced.

[0024] The connection control unit 61 for external telephone terminals and the connection control unit 51 for voice servers are tunneled by a so-called VPN (Virtual Private Network) or the like, so high security can be obtained. These connection control units 51 and 61 are controlled by software such as a normal application. Since the connection control unit 61 for external telephone terminals and the connection control unit 51 for voice servers always exchange IP address information in both directions, they can be automatically reconnected even if the communication is disconnected, and two-way always-on connection is possible.

[0025] As the communication protocol between the connection control unit 61 for external telephone terminals and the connection control unit 51 for voice servers, any method may be used as long as it is a communication protocol that can be used, such as TCP or UDP. Preferably, it is UDP communication. UDP communication does not require connection establishment such as the 3-way handshake of TCP, so the load is small. Also, if the correct information is not included in the first encrypted information, it does not respond, so it is also preferable in terms of security.

[0026] The call control unit 62 has a function of relaying call control messages and voice packets based on call control processing such as SIP and performing call processing. Further, the call control unit 62 is registered with a unique extension number for internal use assigned in advance to the external telephone terminal 60 and the IP address of the external telephone terminal 60 associated therewith, and confirms the transfer destination of the voice packet. Thereby, the call control unit 62 has a function of connecting the external telephone terminal 60 to the telephone system 100 as a virtual extension telephone device by processing the voice packets exchanged with the telephone system 100.

[0027] [Operation of Telephone System] The operation of the telephone system 100 of the present invention will be described in detail with reference to FIG. 3. Here, the originating and terminating call operations when calling the external telephone terminal 60 (extension number = n) from the extension telephone device (extension number = 1) within the company and answering again at the extension telephone device 20 (extension number = 1) will be described.

[0028] In response to the user's operation, the extension telephone device 20 (extension telephone number N = 1) makes an internal call to the extension telephone exchange 10 as a call control message to access the external telephone terminal (extension number N = n) which is a virtual extension telephone device with respect to the telephone system 100, in the same manner as making an internal connection with another extension telephone device 20, to make a call to the extension number N = n (step 201). The extension telephone exchange 10 converts the voice data transmitted from the extension telephone device 20 into voice packets and transmits them to the voice server 50 (step 202).

[0029] The connection control unit 51 for the voice server identifies the corresponding external telephone terminal 60 based on the information transmitted from the extension telephone exchange 10, encrypts the received voice packets (step 203) and transmits them to the corresponding external telephone terminal 60 (step 204). At the external telephone terminal 60, when the connection control unit 61 for the external telephone terminal is due to an application, it is necessary to start the application. If the application is started, since it is a two-way always-connected state with the voice server 50, the user can always wait without any operation.

[0030] The connection control unit 61 for the external telephone terminal decrypts the encrypted voice packet transmitted from the voice server 50 (step 205), reconstructs it into a voice packet, and sends it to the call control unit 62 to receive an incoming call at the extension number N = n. The call control unit 62 of the external telephone terminal 60 makes a call to the extension telephone device 20 (extension number N = 1) that has made a transmission. The connection control unit 61 for the external telephone terminal encrypts the voice packet from the call control unit 62 (step 206) and transmits the encrypted voice packet to the voice server 50 (step 207).

[0031] Next, the connection control unit 51 for the voice server of the voice server 50 decrypts the encryption of the encrypted voice packet received from the external telephone terminal 60 and reconstructs the voice packet (step 208). The reconstructed voice packet is transmitted to the in-house telephone exchange 10 (step 209) and then transmitted to the extension telephone device 20 (extension number = 1) via the in-house extension telephone network (step 210). Thereby, the communication is established.

Industrial Applicability

[0032] The telephone system 100 of the present invention can be easily and inexpensively applied to an existing telephone network.

Explanation of Signs

[0033] 10 In-house telephone exchange 20 Extension telephone device 31 Carrier telephone network 32 Internet network 50 Voice server 51 Connection control unit for voice server 60 External telephone terminal 61 Connection control unit for external telephone terminal 62 Call control unit 100 Telephone system

Claims

1. At least one internal telephone device with an internal line number for use within the premises, A private branch exchange (PBX) that exchanges and connects the internal telephone devices to the internal telephone network and interconnects the internal telephone devices by transmitting and receiving call control messages to and from the internal telephone devices via the internal telephone network, A telephone system comprising: a voice server connected to the PBX via a private network and connected to an external telephone terminal via the Internet, The external telephone terminal includes a connection control unit for the external telephone terminal for connecting to the voice server via the Internet, The voice server includes a connection control unit for the voice server for connecting to the external telephone terminal via the Internet, The connection control unit for the external telephone terminal encrypts voice packets into encrypted voice packets and reconstructs the encrypted voice packets transmitted from the voice server into voice packets, The connection control unit for the voice server encrypts voice packets transmitted from the PBX into encrypted voice packets and transmits them to the external telephone terminal, reconstructs the encrypted voice packets transmitted from the external telephone terminal into voice packets, and transmits the voice packets to the PBX, The connection control unit for the external telephone terminal and the connection control unit for the voice server establish a two-way always-on connection by constantly transmitting and receiving IP address information bidirectionally. A telephone system characterized by this.

2. The voice server is assigned a unique IP address for external telephones and a unique IP address for the private network, The external telephone terminal is assigned a unique IP address for external telephones and the internal line number for use within the premises. The telephone system according to Claim 1, characterized by this.

3. The two-way always-on connection of the connection control unit for the external telephone terminal and the connection control unit for the voice server is a VPN connection. The telephone system according to Claim 1 or 2, characterized by this.

4. The connection control unit for the external telephone terminal transmits only the voice packets as encrypted voice packets to the voice server. The telephone system according to Claim 3, characterized by this.

Images