KR20090095931A - Method of fax call forwarding by using internet protocol based private branch exchange and internet protocol based private branch exchange thereof - Google Patents

Abstract

A fax call switching method using an IP-based PBX and the IP-based PBX having a fax call switching function are provided to receive both a fax call and a voice call through one phone number without allocating a separate phone number for the fax reception. A VoIP(Voice over IP) call is transmitted from a sending fax apparatus to a receiving VoIP telephone(S810). A message for showing that the VoIP call is a fax call is received from the receiving VoIP telephone(S820). The fax call is delivered to an external fax processing apparatus. The message includes information about the sending fax apparatus and receiving VoIP telephone.

Description

FAX Call Transfer Method and Fax Call Transfer Function using IP-based Private Switching System IP-based private exchanger

The present invention relates to voice-over-IP Telephony-related technology, and more particularly to voice in an IP-based private switching network composed of a plurality of subscriber station voice-over-IP telephones, IP-based private exchanges and fax gateways. The present invention relates to an IP private exchange (IP-PBX) and an IP private exchange that transmits a fax call received from an over-IP telephone to a fax gateway.

The voice over internet protocol (VoIP) may be defined as a technology capable of making a voice call using an internet network, which is a packet switched network, in place of a conventional telephone switched network type telephone. In other words, it is a communication service technology that enables a voice of equal or superior quality to that of a public switched telephone network (PSTN) by transmitting a packet of voice data encoded with an analog voice signal based on an Internet protocol. Compared to the conventional telephone service, it is widely spread in the market because it has the advantage of being able to use simultaneously by many people and excellent scalability as well as much cheaper than the existing telephone, and ultimately replace the existing telephone network. Is expected.

Currently used VoIP protocols include H.323, Session Initiation Protocol (SIP), Media Gateway Control Protocol (MGCP), and Media Gateway Control Protocol (MEGACO). Protocol or H.323.

Meanwhile, with the introduction of the VoIP technology, a fax transmission technology, which is a technology for delivering a scanned document image through a conventional PSTN network, needs to be merged with a VoIP service.

For example, there are FoIP (Facsimile over IP) technologies that relay and deliver T.30 protocols of ITU-T (International Telecommunication Unio-Telecommunications), which define protocols between G3 fax devices through a PSTN network, through the Internet network. As such, a fax relay protocol such as the T.37 and T.38 protocols has emerged due to this need.

1A is a conceptual diagram illustrating a method of receiving a fax through the Internet and a public telephone network.

Referring to FIG. 1A, a fax (G3 fax) 110 accesses a conventional PSTN network 120 to initiate a fax transmission based on the T.30 protocol. The gateway 130 receives the fax signal based on the T.30 protocol and packetizes it based on the T.38 protocol, and the gateway 140 converts the received packets back into the fax signal based on the T.30 protocol, thereby converting the PSTN network. Transmit over 150. Finally, the fax 160 receives the fax signal through the PSTN network 150 and proceeds to receive the fax.

That is, the T.38 protocol is used for the purpose of packetizing and transmitting a fax transmission based on the conventional T.30 protocol, and the gateways 130 and 140 packetize and transmit the fax signal based on the T.30 protocol. Performs protocol conversion between the T.38 protocol and the T.30 protocol.

1B is a conceptual diagram illustrating another example of a method of receiving a fax through the Internet and a public telephone network.

Comparing the example illustrated in FIG. 1A to the example illustrated in FIG. 1B, in the example illustrated in FIG. 1B, the receiving side fax 170 is an Internet capable of directly recognizing the T.38 protocol, not a fax apparatus connected to the PSTN network. It is an Internet-Aware Fax (IAF).

That is, in this case, as illustrated in FIG. 1A, the gateway 140 for converting the packets based on the T.38 protocol back to the fax signal based on the T.30 protocol is omitted for the receiving-fax device 160. . Meanwhile, in FIG. 1B, it is assumed that only the receiving side fax apparatus 170 is an Internet fax apparatus. However, when the transmitting side fax apparatus 110 is also an Internet fax apparatus, the transmitting side gateway 130 may be omitted.

Meanwhile, in the configuration illustrated in FIG. 1B, when the receiving side fax apparatus 170 is not an fax apparatus but an Internet telephone (more accurately, a VoIP telephone), the Internet telephone itself is a method for receiving a fax. It may correspond to a packetized fax protocol based on the 38 protocol, and is configured to directly receive a fax transmission based on the T.38 protocol.

However, in a situation where the majority of fax devices operate based on the conventional T.30 protocol rather than the Internet-Aware Fax (IAF) based on the T.38 protocol, the voice-over-IP telephone is a T.38 fax machine. It is not easy to have a function of.

In this situation, in order to receive faxes from a fax device conforming to the T.30 protocol, that is, a fax device connected to a conventional PSTN network, a fax device directly connected to a separate PSTN network in addition to a private Internet switching network in a company or a business office is used. There is a problem in that it must maintain or maintain a gateway that enables conversion between the T.38 protocol and the T.30 protocol on both the sending side and the receiving side. In addition, in the configuration illustrated in FIG. 1A or 1B, there is a problem in that a separate fax reception dedicated telephone number must be separately maintained in order to receive a fax.

On the other hand, VoIP technology provides the advantage of being able to build a private exchange network in a predetermined area such as a company or a business site inexpensively and expandably. When a private switching network is configured, a fax gateway component is added to the private switching network for receiving a fax, and the subscriber station telephones existing in the private switching network are publicly used for receiving or sending a fax.

Figure 1c is a conceptual diagram illustrating the configuration of the IP-based private switching network according to the prior art.

An IP-PBX (IP-PBX) 160 is an essential component for forming an IP-based private exchange network, which is connected to the Internet network 170 and connected to the IP-PBX 160. A call is set up for a call request from outside to various subscriber stations 180 and a call is set up for a call request to outside of the subscriber stations. It also serves as a telephone exchange station that handles the processing of call requests, call setup, call forwarding, etc. between subscriber stations connected to it.

At this time, the subscriber stations 180 connected to the IP-PBX 160 include a plurality of voice-over-IP phones 180-1 to 180-3 and Internet fax (IAF) supporting a plurality of T.38 protocols. Internet-Aware Fax (180-4) may be variously configured.

Meanwhile, the fax gateway 165 is an additional component for fax transmission and reception in an IP-based private switching network. The fax gateway 165 supports a T.38 protocol and receives a fax call transmitted through the IP-PBX 160 to perform a fax reception operation. And it performs the role of attaching the received fax image to the e-mail sent to the specified e-mail address, or stored in a separate fax document server (not shown) connected to the Internet network 170.

In this case, a method of processing a fax received from the outside in an IP-based private switching network as illustrated in FIG. 1C is generally performed as follows.

For example, if a separate telephone number is assigned to receive a fax only and it is determined that the call received from the IP-PBX 160 is a call intended for the corresponding fax receive phone number, the call is forwarded to the fax gateway 165. This is a method of call forwarding.

However, even in this case, there exists a problem of separately assigning a fax reception dedicated telephone number. Typically, in one IP-PBX 160, tens to hundreds of voice-over-IP telephones (as illustrated by 180-1 to 180-3) are connected so that tens or hundreds of voice-only telephone numbers exist. While it is common to use a fax number dedicated to receiving a fax, it is common for several people to share it.

In this case, if a number of people working in an office share one fax phone number for receiving a fax, the contents of the received faxes cannot be distinguished unless the faxes sent to them and the faxes to others are not confirmed. The inconvenience of having to check each one manually is not only a waste of time in this process, but also a private fax document of each other is not protected.

In the case of a station, from the other party's point of view, the fax number must be sent to the subscriber station connected to the private exchange network. It is troublesome to notify the receiver in advance of the fact that the fax is sent or to designate the recipient through a fax cover sheet. In order to solve this problem, there may be a method of allocating a number of fax-only telephone numbers and assigning one fax number to users existing in the private switching network or one fax number to a few users. However, there is an increase in the cost of granting telephone number resources.

This is an aspect of increasing the additional cost, in particular, since the separate fax device must be assigned a dedicated phone number, the cost for using a separate phone number is additionally burdened.

It is an object of the present invention to solve the above problems, so that a fax call can be delivered to a fax gateway according to whether a call designated by a subscriber station is a voice call or a fax call without using a separate fax dedicated phone number. To provide a fax call transfer method of the IP-based private exchange.

Another object of the present invention for solving the problems described above, IP address to forward the fax call to the fax gateway to process according to whether the call designated by the subscriber station is a telephone call or a fax call without using a separate fax dedicated telephone number It is to provide a base private exchange.

One aspect of the present invention for achieving the above object of the present invention is the step of transmitting the voice-over-IP call from the originating fax machine to the receiving voice-over-IP phone, from the receiving voice-over-IP phone A method for operating an IP private exchange comprising receiving a message including information indicating that a voice-over-IP call is a fax call and forwarding the fax call to an external fax processing device.

Here, the message may further include information of the calling fax machine and information of the receiving voice-over-IP telephone.

Here, the message may be a message supported by the H.323 protocol or the Session Initiation Protocol (SIP) protocol.

Here, in the step of forwarding the fax call to an external fax processing device, the information of the receiver voice-over-IP telephone may be configured to be transferred to the external fax processing device together. At this time, the information of the receiver voice-over-IP telephone may be configured to be transmitted through DTMF tones.

Here, the external fax processing device may be a fax gateway.

Here, the fax call may be a fax call supported by the H.323 protocol, the Session Initiation Protocol (SIP) protocol, the Media Gateway Control Protocol (MGCP) protocol, or the Media Gateway Control Protocol (MEGACO) protocol.

Another aspect of the present invention for achieving the above object of the present invention is to determine whether the voice-over-IP call received from the originating fax machine is a fax call, when the voice-over-IP call is confirmed as a fax call, Forwarding a fax call to an external fax processing device and forwarding fax packet data for the fax call to the external fax processing device when the fax call is established between the outgoing fax machine and the external fax processing device. It provides an operating method of the IP private exchange characterized in that.

Here, in the step of transmitting the fax call to an external fax processing device, the fax receiver information may be configured to be delivered to the external fax processing device together. In this case, the fax receiver information may be configured such that information of the receiver voice-over-IP telephone is transmitted through the DTMF tone.

Here, the external fax processing device may be a fax gateway.

Here, the fax call may be a fax call supported by the H.323 protocol, the Session Initiation Protocol (SIP) protocol, the Media Gateway Control Protocol (MGCP) protocol, or the Media Gateway Control Protocol (MEGACO) protocol.

Here, the step of confirming whether the voice-over-IP call is a fax call may be configured to confirm through the information on the calling fax machine. In this case, the step of confirming whether the voice-over-IP call is a fax call may be performed by comparing a telephone number of a fax machine stored in advance with a telephone number of the calling fax machine.

Here, the step of confirming whether the voice-over-IP call is a fax call may be configured to be performed through a message transmitted from a receiving voice-over-IP phone.

One aspect of the present invention for achieving the above object of the present invention is a call signaling unit for transmitting a voice-over-IP call from a calling fax device to a receiving voice-over-IP phone, the receiving voice-over-IP And a message receiving unit for receiving a message including information indicating that the voice-over-IP call is a fax call from a telephone and a control unit for transferring the fax call to an external fax processing apparatus. .

Herein, the message may further include information of the calling fax machine and information of the receiving voice-over-IP telephone. In this case, the message may be a message supported by the H.323 protocol or the Session Initiation Protocol (SIP) protocol.

Here, the control unit may be configured to transmit information of the receiver voice-over-IP telephone to the external fax processing device when the fax call is transmitted to the external fax processing device.

Here, the control unit may be configured to generate and transmit DTMF tones of the recipient voice-over-IP telephone when transmitting the fax call to an external fax processing device.

Another aspect of the present invention for achieving the above object of the present invention is to verify that the voice-over-IP call received from the originating fax machine is a fax call, when the voice-over-IP call is confirmed to be a fax call. A control unit for transmitting a fax call to an external fax processing device and a call signaling unit for transmitting fax packet data for the fax call to the external fax processing device when the fax call is set up between the calling fax machine and the external fax processing device. It provides an IP private exchange comprising a.

Here, the control unit may be configured to deliver the fax receiver information to the external fax processing device when the fax call is delivered to the external fax processing device.

Here, the control unit may be configured to transmit the fax receiver information by generating DTMF tones and transmitting information of the recipient voice-over-IP telephone when the fax call is transmitted to an external fax processing apparatus.

Here, the external fax processing device may be a fax gateway.

Here, the fax call may be a fax call supported by the H.323 protocol, the Session Initiation Protocol (SIP) protocol, the Media Gateway Control Protocol (MGCP) protocol, or the Media Gateway Control Protocol (MEGACO) protocol.

Herein, the controller may determine whether the voice-over-IP call is a fax call through the information on the calling fax machine. At this time, the control unit may check whether the voice-over-IP call is a fax call by comparing a telephone number of a fax machine previously stored with a telephone number of the calling fax machine.

Here, the control unit may be configured to confirm whether the voice-over-IP call is a fax call through a message transmitted from a received voice-over-IP phone.

In the case of using a fax call switching method and a fax call switching function IP-based private exchange according to the present invention, the IP-based private switching network is used to receive a fax call using the telephone numbers of voice telephone subscriber stations existing in the private switching network. Can be configured.

Through this, only the user can view the fax document delivered to him, so as to solve the privacy problem that a large number of users have to handle the private fax document, as well as to handle the voice phone number and the fax phone number separately. It can eliminate the inconvenience.

As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The invention relates to an IP telephony technology that allows both voice calls and faxes to be received at one phone number without the need for a separate fax-only phone number. And a method of implementing a voice-over-IP telephone using the method, or by converting a fax call received at the voice-over-IP telephone from an IP-based private exchange to a fax gateway and processing the method. Embodiments may be configured by implementing a voice-over-IP telephone and an IP-based private exchange.

Hereinafter, various embodiments for achieving the above object of the present invention will be described in detail, but each embodiment may be implemented independently, and the technical spirit included in each embodiment may be combined and implemented. Can be. That is, the technical ideas included in the embodiments described below should not be interpreted depending on each embodiment only.

1) How to receive a fax on your own within a voice-over-IP phone

2 is a conceptual diagram illustrating an operating environment of a voice-over-IP telephone according to the present invention.

Referring to FIG. 2, the voice-over-IP telephone 210 according to the present invention is directly connected to the Internet network 230 or an Internet private exchange (IP-) which maintains a private switching network configured in a predetermined area such as a company or a business place. PBX is connected to the Internet network 230 via a Private Branch Exchange (220). In addition, the outgoing fax 260 is connected to the PSTN network 250 and connected to the Internet network 230 via the gateway 240. That is, the present invention assumes that the outgoing fax 260 is a fax that supports the T.30 protocol, and the outgoing fax 260 may be a device exclusively for receiving and receiving a fax. And a fax modem and a computer for sending a fax by a fax program.

Meanwhile, the components collectively referred to herein as the gateway 240 may include various kinds of detailed components, or may be divided into various detailed gateways. In particular, the gateway 240 refers to a call or a call from a fax or a telephone connected to the PSTN network into a voice signal packet based on the VoIP protocol and packetized, or vice versa. It is a component that converts the voice signal.

In other words, the gateway performs a media conversion function that converts media in the PSTN network and IP packets in the Internet. In this case, the media conversion function converts a voice signal packet by a voice codec such as G.723 or G.729 used in VoIP technology into a G.711 format suitable for a PSTN network, or performs reverse conversion. In addition, the gateway performs a signaling conversion function for interconverting the signaling signaling protocol SS7 (also called No. 7) of the PSTN network with an IP signaling protocol such as H.323 or SIP. Thus, the term generically referred to hereinafter as gateway is used to generically refer to the above-described media gateway and signaling gateway. In addition, a media gateway controller that manages the media gateway and the signaling gateway as a whole may also be collectively referred to by the term gateway.

Accordingly, the present invention provides a fax receiving method and a fax of a voice-over-IP telephone which can be applied to a process of receiving a fax by the voice-over-IP telephone 210 through a fax call generated from the outgoing fax 260. It relates to the configuration of a receivable voice-over-IP telephone.

First, a method of receiving a fax through a voice-over-IP telephone according to the present invention will be described below with reference to FIGS. 3 and 2.

3 is a flowchart illustrating a fax reception method through a voice-over-IP telephone according to the present invention.

Referring to FIG. 3, the method for receiving a fax through a voice-over-IP telephone according to the present invention includes a call signaling step S310, a fax call determining step S320, and a fax receiving and processing step S330. Can be.

Hereinafter, each step of configuring a fax receiving method through the voice-over-IP telephone according to the present invention will be described in detail.

Call signaling step

First, the call signaling step S310 is ultimately generated from the outgoing fax 260 between the voice-over-IP telephone 210 and the outgoing fax 260 according to the present invention connected to both ends of the internet network 230. A step of performing a call signaling procedure for handling a call between the two.

That is, the call signaling step S310 may be performed between the voice-over-IP telephone 210 and the outgoing fax 260 directly connected to the Internet network or indirectly connected to the Internet network 230 through the IP private exchange 220. Signaling a VoIP call through a call signaling procedure based on the VoIP protocol such as the H.323 protocol or the SIP protocol.

The VoIP protocol includes H.323, SIP, MGCP, and MEGACO, and the call signaling step S310 may perform a call signaling procedure using at least one of various protocols as described above. The most commonly used protocols are the SIP and H.323 protocols.

The H.323 protocol includes sub-protocols such as the H.225 protocol used for call establishment between terminals and the H.245 protocol used for sending and receiving call control messages. Therefore, in detail, a call signaling procedure based on the H.323 protocol may refer to a call signaling procedure based on the H.225 protocol.

The SIP protocol is an extensible protocol that accommodates elements of HTTP and SMTP, which are conventional Internet protocols. The SIP protocol uses a client / server structure of HTTP and a Uniform Resource Location (URL) method, and a text encoding method and a header format of SMTP. Use

Fax Call Determination Step

Next, the fax call determination step (S320) is performed.

Fax call determination step (S320) is a fax call determination step of determining whether the call received through the call signaling step (S310) is a fax call, a method for receiving a fax call transfer instruction by the user, caller's telephone number (CID) It can be done through two methods of discriminating by fax call using.

In the case of a method of receiving a fax transfer instruction by a user, when the outgoing fax 260 starts sending a fax, the voice-over-IP telephone 210 and the outgoing fax 260 are either H.323 or SIP. After proceeding with the call signaling procedure based on the protocol in the call signaling step S310, a bell indicating that the call has arrived to the voice-over-IP phone 210 (eg, in the H.323 procedure, 'Alerting' , '180 Ringing' in SIP procedure).

At this time, the user connects a call by lifting the handset of the voice-over-IP phone and confirms by hearing a fax tone that a fax signal has been transmitted through the handset, and then the voice-over-IP phone 210 ) Will give a 'fax call transfer instruction' indicating that a fax call has been received.

In this case, the 'fax call switching instruction' may be clicked on a predetermined dedicated key button or a predetermined soft key button provided on the voice-over-IP phone 210 or a touch pad provided on the voice-over-IP phone 210. Alternatively, the voice-over-IP telephone 210 informs that the incoming call is a fax call by touching a touch screen.

In the case of the method of determining a fax call using the caller's telephone number, a ringing ring indicating that the call has arrived, notifying the user that the call has arrived, and establishing a call between the outgoing fax 260 and the voice-over-IP telephone 210 Instead of having the user listen to the fax tone and determine that the received call is a fax call, the voice-over-IP phone 210 itself may operate in a way to determine if the call currently being received is a fax call.

For example, the voice-over-IP phone 210 interprets a call request message such as a Q.931 Setup message according to the H.323 protocol or an INVITE message according to the SIP protocol, and confirms a caller ID (CID). Search the phone book stored in the memory of the voice-over-IP phone 210 to find out whether the caller's phone number is registered as a 'fax device', and the caller's phone number is the phone of the fax device. If it is a number, it is operable to determine that the incoming call is a fax call.

The difference between the two methods is that, in the case of receiving a fax switching instruction by the user, a call is established between the telephone 210 and the outgoing fax 260, and the user confirms the fax tone through the handset. In the case of using the caller's phone number, the call request message (Q.931 setup message or INVITE message) received during the process of establishing a call between the phone 210 and the outgoing fax machine 260 is required. ) Can be identified as a fax call without user intervention.

On the other hand, if the call received in the fax call determination step (S320) is a normal voice call instead of a fax call, the process proceeds to the normal voice call processing step (S325). The description of the normal voice call processing step S325 is omitted.

Fax Receive and Processing Steps

Next, a fax reception and processing step S330 is performed.

When it is determined that the received call is a fax call, the step of receiving and processing a fax (S330) receives a series of packet data including a fax signal from the outgoing fax 260 through the established call, and receives the series of packet data. After converting to a fax signal by decoding, the fax signal is recognized as a fax signal based on the T.30 protocol and a fax reception operation corresponding to the fax signal is performed.

The fax reception and processing step S330 may be configured to include a packet reception step S331, a fax signal processing step S332, and a fax reception step S333 in detail, and will be described in detail with reference to FIG. 4.

4 is a conceptual diagram illustrating a fax reception and processing step applied to a fax reception method through a voice-over-IP telephone according to the present invention.

The packet receiving step S331 is a step of receiving packet data 420 including a fax signal 410 based on the T.30 protocol.

Referring to FIG. 4, the packet data 420 is signal data 421 compressed according to the standards of G.711, G.723, G729, etc.-in the case of a voice call, the voice signal will be a compressed signal. According to the method of receiving a fax, a fax signal from an outgoing fax is treated as a voice signal, and means a packet including compressed data (for example, RTP-Realtime Transport Protocol packet, more precisely, RTP / UDP / IP packet). Herein, the compressed signal refers to a signal in which the fax signal 410 generated by the originating fax machine 260 is encoded and compressed according to the T.30 protocol.

In other words, the packet data 420 containing the fax signal based on the T.30 protocol is used to modulate the fax signal (data including bitmap information of the scanned image) generated by the fax device based on the T.30 protocol, such as PSK and QAM. A packet data obtained by packetizing signal data 421 encoded according to a predetermined codec standard by treating a modulated signal and predetermined control signals as a voice signal. In other words, the originating fax apparatus 260 is connected to the PSTN network, and the fax signal (analog signal) generated by the fax apparatus is not converted to another protocol such as the T.38 protocol. This means that the fax signal is treated as a voice signal as it is, packetized, and transmitted to the voice-over-IP telephone 210.

That is, in a component such as the gateway 240 to which the outgoing FAX device 260 is connected through a PSTN network, the FAX signal 410 based on the T.30 protocol generated by the outgoing FAX device is separated from the T.38. Without the operation of converting to a separate Internet fax protocol, the fax signal itself is treated as an audio signal, encoded, and the packet data 420 is generated and transmitted through the Internet network and received by the voice-over-IP phone 210.

Next, the fax signal processing step S332 is a step of converting the packet data 420 received in the packet reception step S331 into a fax signal 510.

Referring to FIG. 4, in the fax signal processing step S332, the signal data portion 421 encoded in the packet data 420 is extracted, decoded, and converted to the original fax signal 510. Accordingly, the fax signal 510 output through the fax signal processing step S332 is a signal in which the T.30 fax signal 410 generated by the calling fax machine is reproduced.

Finally, in the fax reception step (S333), the fax signal 510 converted and output in the fax signal processing step (S332) is recognized as a fax signal based on the T.30 protocol and a fax reception operation corresponding to the fax signal is performed. Step to perform.

Recognizing the output fax signal 510 as a fax signal based on the T.30 protocol and receiving a fax corresponding to the fax signal may be performed by a receiving operation of a G.3 fax apparatus connected to a conventional PSTN network. The same can be done.

On the other hand, printing means such as a dedicated fax machine is rarely added to the Internet telephone, and since most of the faxes do not need to be printed and output, the fax receiving step (S333) is performed in various ways as follows. It may be configured to deliver the received fax image to the user.

First, the voice-over-IP phone 210 may be configured to convert the received fax image into a file and send the email to an e-mail address previously designated by the user using the file as an attachment. For example, the received fax image is converted into a document in the form of MIME (Multipurpose Internet Mail Extension) including information related to the reception time of the fax and the sender information of the fax, and designated e-mail using the Simple Mail Transfer Protocol (SMTP) protocol. It may be configured to send this mail to an address. In this case, the voice-over-IP phone 210 may also serve as a mail server for directly sending an email, but converts the fax image into an image file such as a TIF and delivers it to a separate mail server. The mail server may be configured to proceed with the mail sending procedure described above.

Secondly, the voice-over-IP telephone 210 is configured to convert the received fax image into a file and store the file in a predetermined storage space in association with a reception time of the fax and caller information of the fax. It may be. In this case, the predetermined storage space may be configured to be stored in a predetermined document server (which may be referred to as a document server, for example, a fax document server) connected to the Internet telephone through a wired network.

In this case, the first and second configurations are possible only by simple software implementation since the voice-over-IP telephone 210 is connected to the Internet network.

Third, it is configured to output a received fax image stored in its own memory inside the voice-over-IP telephone 210 or a fax image stored in the document server through printing means connected to the voice-over-IP telephone 210. Can be. Here, the printing means is connected to the voice-over-IP telephone 210 network printer (where the network printer can be directly connected to the TCP / IP network), directly connected printer (USB, IEEE-1394, parallel port, etc.) ) And a printing device built into the telephone 210.

2) Configuration of Voice-Over-IP Phone to Receive Faxes by Itself

Fig. 5 is a block diagram showing a configuration example of a fax reception function voice-over-IP telephone according to the present invention.

5, the fax receiving function Internet phone 600 according to the present invention includes a call signaling unit 610, a packet receiving unit 620, a fax signal processing unit 630, a fax call determining unit 640 and a fax receiving unit ( 640 may be configured.

The call signaling unit 610 is directly connected to the Internet network 230 or indirectly through the IP private exchange 220 to perform a VoIP call signaling procedure based on a VoIP protocol such as an H.323 protocol or a SIP protocol. Component.

As mentioned above, the VoIP protocol includes H.323, SIP, MGCP, and MEGACO, and the call signaling unit 610 may perform a call signaling procedure using at least one of various protocols as described above. The most commonly used protocols are the SIP and H.323 protocols.

The H.323 protocol includes sub-protocols such as the H.225 protocol used for call establishment between terminals and the H.245 protocol used for sending and receiving call control messages. Therefore, in detail, a call setup procedure based on the H.323 protocol may refer to a call setup procedure based on the H.225 protocol.

The SIP protocol is an extensible protocol that accommodates elements of HTTP and SMTP, which are conventional Internet protocols. The SIP protocol uses a client / server structure of HTTP and a Uniform Resource Location (URL) method, and a text encoding method and a header format of SMTP. Use

The packet receiver 620 is directly connected to the Internet network 230 or indirectly through the IP private exchange 220 to receive a series of packet data from a call established by the call signaling unit 610. Element.

To this end, the packet receiver 620 may be configured to include an Ethernet controller and the like connected through an RJ-45 terminal connected to an external UTP cable. Alternatively, the packet receiver may be configured as a terminal device of an optical subscriber network such as GE-PON and WDM-PON represented by FTTH (Fiber To The Home). Similarly, it is possible to receive packet data (for example, RTP packet) transmitted from the outside by being connected to the Internet network through a cable modem, ADSL, VDSL, PLC, or the like.

The fax signal processor 630 is a component that extracts, decodes and encodes the encoded signal data portion 421 from the series of packet data received from the packet receiver 620 to reproduce the original fax signal 510.

The fax call determination unit 640 is a component that determines whether a call received through the call signaling unit 610 is a fax call. In this case, the method for determining whether a call received through the call signaling unit 610 is a fax call is a method of receiving a fax call switch instruction by the user as described above, using a caller's telephone number. A fax call discrimination method can be used.

When a method for receiving a fax call transfer instruction by a user is applied, the voice-over-IP telephone 600 treats the fax signal output by the fax signal processing unit 630 as a voice signal and converts it to sound for reproduction. Speaker 631 and the input device 641 to be instructed to switch the fax call from the user should be provided. In addition, the input device 641 may be an input device such as a predetermined keypad, touch pad, touch screen, and the like. Fax call switching may be performed by pressing a predetermined key button or touching a touch pad or a touch screen. You can be directed.

At this time, the fax call determining unit 640 reproduces the fax signal output by the packet receiving unit 620 and the fax signal processing unit 620 from the call established by the call signaling unit 610 to the user through the speaker 631. If the user determines that the call received through the speaker contains a fax tone, the user may be configured to receive a fax call switching instruction through a predetermined input device 641.

When a fax call determination method using a caller's telephone number is applied, the fax call determination unit 640 receives a caller's telephone number extracted in the process of performing a call signaling procedure by the call signaling unit and receives the caller's telephone number. It may be configured to determine whether a call set up through the call setting unit is a fax call by querying a database storing telephone numbers of predetermined fax machines.

Finally, when the fax receiver 650 determines that the call received by the fax call discriminator 640 is a fax call, the fax receiver 650 receives the T.30 received fax signal through the packet receiver 620 and the fax signal processor 630. A component that recognizes a fax signal based on a protocol and performs a fax reception operation. For example, the fax receiving unit 650 may include a software or hardware fax receiving module that performs a conventional G.3 fax function.

3) Fax call transfer method in IP-based private exchange

6 is a conceptual diagram illustrating an operating environment of an IP-based private exchange according to the present invention.

Referring to FIG. 6, the IP-based private exchange 710 according to the present invention is connected to the Internet network 730 and to a plurality of subscriber station telephones 720-1 to 720 -N. In addition, the IP-based private exchange is connected with a fax gateway 735 for handling fax transmission and reception for the subscriber stations. In addition, a calling station fax that sends a fax to one of a plurality of subscriber stations 720-1 to 720-N connected to the IP-based private exchange 710 through the corresponding Internet network 730 and the IP-based private exchange 710. Device 740-1 or 740-2 is present. At this time, the originating station fax apparatus is connected to the Internet network 730 through an Internet Aware Fax (IAF) 740-1 or a predetermined gateway 750, which directly accesses the Internet network 730 and sends a fax. It may be a conventional fax machine 740-2 connected to a public telephone network (PSTN) 760 for sending a message. In addition, the originating station fax apparatus may be a fax modem for sending a fax by a fax sending program (for example, a word processor and a fax program) in a personal computer or the like.

At this time, the gateway 750 performs a media conversion function for converting media of the PSTN network and IP packets of the Internet. In addition, the gateway 750 performs a signaling conversion function for inter-converting an SS signaling (Signaling System 7; also called No. 7), which is a call signaling protocol of the PSTN network, and an IP signaling protocol such as H.323 or SIP. Thus, the gateway 750 is used herein to generically refer to the media gateway and signaling gateway described above. In addition, a media gateway controller that manages the media gateway and the signaling gateway as a whole may also be collectively referred to as the gateway.

That is, the IP-PBX 710 according to the present invention assumes an IP-PBX (Private Branch Exchange) that maintains a private exchange network configured in a predetermined area of a company or a business place.

The IP-based private exchange 710 receives a call request through the Internet network 720 for a plurality of subscriber station telephones 720-1 to 720-N connected to the IP-based private exchange 710, and It interprets the call request and serves as an exchange to set up a call between the subscriber stations 720-1 to 720-N as targets and an external originating station 740-1 or 740-2.

At this time, the external calling station is the fax device 740-1 or 740-2, and the external calling station is connected to any one of the subscriber station telephones 720-1 to 720-N connected to the IP-based private exchange 710. When a fax call is requested by phone number, a fax call switching method of an IP-based private exchange according to the present invention is applied.

The fax call switching method of the IP-based private exchange according to the present invention may be composed of two embodiments: a method of using a fax call switching instruction from a subscriber station and a method of converting a fax call using a calling party number.

Hereinafter, the above-described two embodiments will be described with reference to the conceptual diagram of FIG. 6.

How to use fax call transfer instructions from a subscriber station

7 is a flowchart illustrating an embodiment of a fax call switching method of an IP-based private exchange according to the present invention.

Referring to FIG. 7, an embodiment of a fax call switching method of an IP-based private exchange according to the present invention includes a call signaling step (S810), a fax call determination step (S820), and a fax call switching step (S830). Can be configured.

The call signaling step S810 is connected to at least one subscriber station telephones 720-1 to 720 -N and the Internet network 730, so that outgoing faxes 740-1 or 740-2, such as 740-1, can be used. Receive a call request from one of the subscriber station phones (e.g. 720-1) and forward the call request to the subscriber station phone or forward the call request and perform a call establishment procedure for the call request. It's a step.

That is, the call signaling step S810 may include one of a plurality of subscriber station telephones 720-1 to 720-N (eg, 720-1) and an outgoing fax 740-1 connected to the IP-based private exchange 710. 740-2), a step of establishing a VoIP call through a procedure based on a VoIP protocol such as an H.323 protocol or a SIP protocol.

The VoIP protocol includes H.323, SIP, MGCP, and MEGACO, and the call signaling step S810 may perform a call signaling procedure using at least one of various protocols as described above. The most commonly used protocols are the SIP and H.323 protocols.

The H.323 protocol includes sub-protocols such as the H.225 protocol used for call establishment between terminals and the H.245 protocol used for sending and receiving call control messages. Therefore, in detail, a call signaling procedure based on the H.323 protocol may refer to a call signaling procedure based on the H.225 protocol.

The SIP protocol is an extensible protocol that accommodates elements of HTTP and SMTP, which are conventional Internet protocols. The SIP protocol uses a client / server structure of HTTP and a Uniform Resource Location (URL) method, and a text encoding method and a header format of SMTP. Use

Next, the fax call determination step (S820) determines whether the call currently requested is a fax call using the caller number identified from the call request message according to the voice-over-IP protocol received through the call signaling step (S810). Or determining whether the call established by the call signaling step (S810) is a fax call. At this time, when it is determined that the received call is a fax call, the subscriber station telephone is transmitted from the subscriber station telephone to the IP-based private exchange 710 according to the present invention, and the IP-based private exchange 710 is transmitted to the fax. 'Call call indication' can be determined that the received call is a fax call.

That is, the fax call determination step S820 may be largely performed in two ways.

First, a call is established between the called party's phone (e.g. 720-1) and the outgoing fax (e.g. 740-1), and the user confirms that the fax tone is delivered through the handset of the called party's phone. Inputs a fax call to a subscriber station telephone through a predetermined input device, the subscriber station telephone transmits a 'fax call transfer instruction' to the IP-based private exchange 710.

That is, in this case, when the outgoing fax 740-1 starts sending a fax, the subscriber station telephone 720-1 and the outgoing fax 740-1 are called under the arbitration of the IP-based private exchange 710. The signaling procedure is performed in the call signaling step S810, and a ringing signal indicating that the call has arrived at the subscriber station telephone 720-1 (for example, an 'Alerting' step in the H.323 procedure and a '180 in the SIP procedure). Ringing 'step).

At this time, the user connects a call off the hook of the subscriber station telephone 720-1 and confirms by fax tone that the fax signal has been transmitted through the handset, and then the subscriber station telephone 720-P. Through 1), the 'fax call transfer instruction' indicating that the fax call is received is transmitted to the IP-based private exchange 710.

At this time, the 'fax call switching instruction' is clicked on a predetermined dedicated key button or a predetermined soft key button provided in the subscriber station telephone 720-1, or a touch pad or touch provided on the subscriber station telephone 720-1. By touching the screen or the like, the call currently received at the subscriber station telephone 720-1 is transmitted to the IP-based private exchange 710 as a fax call.

Secondly, the called subscriber station phone (eg, 720-1) analyzes the call request message received from the IP-based private exchange 710 in the call signaling step (S810), extracts the calling party number, and extracts the extracted calling party number from the outside. This is a method of recognizing that a received call is a fax call when the caller's telephone number is registered as a 'fax device' by searching in a phone book that stores telephone numbers of fax devices in advance.

For example, the subscriber station phone 720-1 interprets a call request message such as a Q.931 Setup message according to the H.323 protocol or an INVITE message according to the SIP protocol, and confirms a caller ID (CID). If the caller's phone number is a phone number registered as a 'fax device' by searching the phone book that stores the phone numbers of external fax devices in advance, and if the caller's phone number is the phone number of the fax device, It may be configured to determine that the incoming call is a fax call. In this case, a call is not required to be established between the called subscriber station telephone 720-1 and the outgoing fax machine, which is different from the above-described first method, that is, a user command to send a 'fax call transfer instruction' through the input device. . This is because the user does not need to confirm that the fax tone is transmitted through the handset of the terminating subscriber station telephone.

Meanwhile, the 'fax call diversion instruction' may be made by message transmission between the subscriber station telephone 720-1 and the private exchange 710. For example, certain SIP messages defined separately in subscriber station telephones 720-1 and private exchange 710 or in existing SIP messages (e.g., messages that subscriber station telephones forward to request a call transfer to a private exchange). The subscriber station telephone 720-1 may be configured to convey a 'fax call transfer indication' by defining a field or including a predetermined indication within an existing field by sending a message to the private exchange 710.

8 is a conceptual diagram illustrating an example of a SIP message used to receive a fax call switch instruction in a fax call switch method of an IP-based private exchange according to the present invention.

Referring to FIG. 8, in the fax call switching method of the IP-based private exchange according to the present invention, the 'fax call transfer instruction' transmitted from the subscriber station telephone 720-1 to the IP-based private exchange according to the present invention is a SIP message. It is illustrated that a 're-INVITE' message can be used.

In the SIP protocol, a 're-INVITE' message is a message mainly used to send from a called party to a private exchange (PBX) for call forwarding. In FIG. 8, only a message header part is shown. Doing.

 Referring to FIG. 8, a method name 're-INVITE' 811 indicating a 're-INVITE' message is described on a start line 810, and an originator field 'From' 830 is called. The phone number or e-mail address of the fax, or the recipient field ('To'; 840) specifies the telephone number (extension number) or e-mail address of the receiving subscriber's phone, or the route field ('Via'; do.

As mentioned above, the 'fax call transfer indication' transmission according to the present invention is to transmit a SIP message by defining a predetermined field in a separately defined SIP message or an existing SIP message, or by including a predetermined indication value in an existing field. It can be made by. Therefore, in the SIP message illustrated in FIG. 8, in writing a predetermined indication value (eg, a string string called 'FAX') in a content type field ('content-Type') 850 that designates a media type of a message body, Sending a fax call transfer indication command is illustrated.

On the other hand, if it is determined in step S820 that the received call is a normal voice call instead of a fax call, the process proceeds to a normal voice call processing step S825. A detailed description of the conventional voice call processing step (S825) will be omitted, but since the 'fax call switch instruction' is not transmitted to the IP-based private exchange 710, the subscriber station telephone is recognized as a normal voice call in this case. The call of 720-1 and the calling station (in this case the calling station will not be a fax machine) will continue.

Next, when it is determined that the established call is a fax call, in step S830, the call is forwarded by resetting the established call to a call between the fax gateway 735 and the outgoing fax 740-1. ) Step.

The call establishment procedure and call transfer procedure between the outgoing fax 740-1, the subscriber station telephone 720-1, and the fax gateway 735 performed by the IP-based private exchange 710 are described in the H.323 protocol as described above. Or it may be made through a procedure based on the VoIP protocol such as the SIP protocol.

At this time, when the call is switched to the fax gateway 735 and the fax call is set up by hooking off the fax gateway 735, the fax packet data is transferred from the originating fax to the IP-based private exchange 710. And forwarded to the fax gateway 735. In addition, the IP-based private exchange 710 transmits the extension number of the receiving subscriber station to the fax gateway 735 through a dual tone multi frequency (DTMF) tone or the like. The fax gateway 735 sends the received fax image to an email address corresponding to the extension number of the receiving subscriber station or displays the extension number of the receiving subscriber station and stores the received fax image in a predetermined storage space.

How to Transfer Fax Calls Using Caller ID

9 is a flowchart illustrating another embodiment of a fax call switching method of an IP-based private exchange according to the present invention.

9 is a method of determining whether a call received using a caller number is a fax call in 'method of using a fax call transfer instruction from a subscriber station' described above with reference to FIG. 7. Similar to In the above-described method, however, the receiving subscriber station telephone 720-1 determines whether the call is a fax call, and the IP-based private exchange 710 transmits from the receiving subscriber station telephone 720-1. Although receiving the 'fax call switching instruction' to perform a fax call determination step (S820), the method illustrated in FIG. 9 is a process for determining whether the call is a fax call using the calling party number according to the present invention. 710) there is a difference in that it is done in itself.

9, another embodiment of the fax call switching method of the IP-based private exchange according to the present invention, call request receiving step (S910), caller ID extraction step (S920), fax call determination step (S930) and fax It may be configured to include a call transfer step (S940).

First, the call request receiving step (S910) is connected to at least one subscriber station telephones 720-1 to 720-N and the Internet network 730, from the outgoing fax (740-1, 740-2) Receiving a call request according to the voice-over-IP protocol for one of the subscriber station telephones (eg 720-1).

That is, the call request receiving step S910 may include one of a plurality of subscriber station telephones 720-1 to 720-N (eg, 720-1) and an outgoing fax machine 740-1 connected to the IP-based private exchange 710. Or 740-2), receiving a VoIP call request through a procedure based on a VoIP protocol such as an H.323 protocol or a SIP protocol.

The call request receiving step S910 is a process corresponding to a part of the call signaling procedure performed in the call signaling step S810 described above with reference to FIG. 7, and similarly, a procedure based on a VoIP protocol such as an H.323 protocol or a SIP protocol. Through the step, the call setup request for the subscriber station telephone 720-1 from the outgoing fax 740-1.

In this case, the call request may be received by receiving a call request message, such as a Q.931 Setup message according to the H.323 protocol or an INVITE message according to the SIP protocol, from the outgoing fax 740-1.

Next, the calling party number extracting step (S920) is a step of extracting the calling party number from the call request received in the call request receiving step (S910).

As mentioned above, the IP-based private exchange 710 interprets a call request message such as a Q.931 Setup message according to the H.323 protocol or an INVITE message according to the SIP protocol to obtain a caller ID (CID). Check the phonebook that stores the phone numbers of the external fax devices in advance, and search whether the caller's phone number is registered as a 'fax device', and the caller's phone number is the phone number of the fax device. Can be configured to determine that the incoming call is a fax call.

On the other hand, if it is determined in step S930 that the received call is a normal voice call instead of a fax call, the process proceeds to a normal voice call processing step S935. A detailed description of the conventional voice call processing step S935 is omitted, but since it is recognized as a normal voice call, it is performed by continuing the call signaling procedure of proceeding with the call establishment based on the call request message received from the originating station. will be.

Finally, the fax call switching step (S940), if it is determined in the fax call determination step (S930) that the call request is a fax call request, the step of switching the call request to a call between the fax gateway and the outgoing fax; to be.

The call establishment procedure and call transfer procedure between the outgoing fax 740-1, the subscriber station telephone 720-1, and the fax gateway 735 performed by the IP-based private exchange 710 are described in the H.323 protocol as described above. Or it may be made through a procedure based on the VoIP protocol such as the SIP protocol.

At this time, when the call is switched to the fax gateway 735 and the fax call is set up by hooking off the fax gateway 735, the fax packet data is transferred from the originating fax to the IP-based private exchange 710. And forwarded to the fax gateway 735. In addition, the IP-based private exchange 710 transmits the extension number of the receiving subscriber station to the fax gateway 735 through a dual tone multi frequency (DTMF) tone or the like. The fax gateway 735 sends the received fax image to an e-mail address corresponding to the extension number of the receiving subscriber station or displays the extension number of the receiving subscriber station and stores the received fax image in a predetermined storage space.

As described above, the difference between the method using the fax call transfer instruction by the subscriber station telephone and the fax call transfer method using the caller ID is to transfer the call request message received from the outgoing fax to the subscriber station telephone 720-1. Or a call needs to be established between the subscriber station telephone and the outgoing fax.

That is, in the case of the method of using the fax call transfer instruction by the subscriber station telephone, a call is established between the outgoing fax 740-1 and the subscriber station telephone 720-1 once, and the established call is a fax call. The incoming call 740-1 and the fax gateway 735 transmit a call between the subscriber station telephone 720-1 and the outgoing fax 740-1 by receiving a fax call transfer instruction by the user detected by the hearing. The call will be transferred to the call. Alternatively, the subscriber station phone analyzes the call request message, extracts the calling party number, checks whether the call is from a fax, and sends a call between the subscriber station telephone 720-1 and the outgoing fax 740-1. The call is switched between 1) and the fax gateway 735.

On the other hand, in the method of 2), a call is established between the outgoing fax 740-1 and the subscriber station telephone 720-1, or the call request message from the outgoing fax 740-1 is transmitted to the subscriber station telephone ( Instead of forwarding to 720-1, the IP-based private exchange 710 directly analyzes the call request message to determine only the caller's number. Instead of establishing a call, the call is transferred to the call between the outgoing fax 740-1 and the fax gateway 735 (in this case, instead of transferring the established call, only the call request is received and the receiver establishes the changed call). named blind forwarding).

As mentioned above, the operation of the fax gateway 735 operating in conjunction with the IP-based private exchange according to the present invention may be configured similarly to the conventional fax gateway and its operation method and configuration. However, when the IP-based private exchange receives the 'fax call transfer instruction', the subscriber station telephone 720 first designated and dialed by the calling fax 740-1 in the process of switching the call to the fax gateway 735. An extension number of -1) needs to be transmitted to the fax gateway 735. This extension can be forwarded by being included in the SIP message associated with the call transfer to the fax gateway. Alternatively, the transmission of the extension number may be transmitted from the IP-based private exchange to the fax gateway using dual tone multi frequency (DTMF) tones.

That is, the fax gateway 735 needs to distinguish the reception destination of the received fax by using the extension number of the subscriber station telephone 720-1 which has been the destination.

For example, the fax gateway 735 receives the fax for the fax call converted by the IP-based private exchange 710, converts the received fax image into a file, and converts the received fax image into a file, and attaches the file as an attached document. It may be configured to send an e-mail to a predetermined e-mail address corresponding to the extension number of the telephone 720-1. For example, the received fax image is converted into a document in the form of MIME (Multipurpose Internet Mail Extension) including information related to the reception time of the fax and the sender information of the fax, and designated e-mail using the Simple Mail Transfer Protocol (SMTP) protocol. It may be configured to send this mail to an address. In this case, the fax gateway may serve as a mail server that directly sends an e-mail, but the fax gateway converts the fax image into an image file such as a TIF and delivers the image to a separate mail server, and the mail server is described in detail in the mail server. It can also be configured to proceed with the mail sending procedure.

In addition, the fax gateway 735 converts the received fax image into a file, and stores the file in a predetermined storage space in association with the reception time of the fax, caller information of the fax, and the extension number of the telephone number of the subscriber station to which the fax is to be received. It can also be configured to store in. In this case, the predetermined storage space may be configured to be stored in a predetermined document server (which may be referred to as a document server, for example, a fax document server) connected to the fax gateway 735 through a wired network.

In addition, it may be configured to output a received fax image stored in its own storage space inside the fax gateway 735 or a fax image stored in the document server through printing means connected to the fax gateway 735. Here, the printing means includes a network printer connected to the fax gateway 735 (where the network printer can be directly connected to a TCP / IP network), a directly connected printer (USB, IEEE-1394, parallel port, etc.) and a fax gateway. It may be a printing device built in 735 and the like.

4) Configuration of IP-based Private Exchange with Fax Call Transfer

10 is a block diagram illustrating an example of a configuration of an IP-based private exchange according to the present invention.

Referring to FIG. 10, the IP-based private exchange 900 according to the present invention may include a call signaling unit 910, a fax switch instruction receiving unit 920, and a controller 930. One configuration example of an IP-based private exchange according to the present invention illustrated in FIG. 10 is a configuration of an IP-based private exchange when a method of using a fax call transfer instruction by a subscriber station telephone according to the present invention described with reference to FIG. 7 is applied. An example is shown.

The call signaling unit 910 is a component that is connected to at least one subscriber station telephone and the Internet network, and establishes a call between at least two of the subscriber station telephone, an outgoing fax and a fax gateway connected through the Internet network.

That is, the call signaling unit 910 specifies the Internet network 930 and the plurality of subscriber station telephones 920-1 to 920-N (hereinafter, 920-1 is designated as the target subscriber station telephone), and the fax gateway 935. ), Which is connected to the outgoing FAX 940-1 and performs a VoIP call signaling procedure based on the VoIP protocol such as the H.323 protocol or the SIP protocol.

As described above, VoIP protocols include H.323, SIP, MGCP, and MEGACO, and the call signaling unit 910 may perform a call signaling procedure using at least one of various protocols as described above. The most commonly used protocols are the SIP and H.323 protocols, and the call signaling unit 910 also sends messages based on the SIP and / or H.323 protocols to the fax gateway 935 and outgoing fax 940-1. It is a component that transmits and receives between subscriber station telephones 920-1 to 920-N and performs a VoIP call signaling procedure.

The fax switch instruction receiving unit 920 is a component for receiving a fax switch instruction from the subscriber station telephone 920-1.

In this case, the 'fax call switching instruction' may be made by message transmission between the subscriber station telephone 920-1 and the private exchange 910. For example, the subscriber station telephone 920 may be defined by defining a predetermined field in a SIP message or an existing SIP message defined separately in the subscriber station telephone 920-1 and the private exchange 910, or by including a predetermined indication value in the existing field. -1) can be configured to convey the 'fax call transfer indication' by sending a message to the private exchange 910.

Finally, the control unit 920 establishes a call requested from the outgoing fax 940-1 to the subscriber station telephone 920-1 as a receiver between the subscriber station telephone and the outgoing fax, and the fax switch instruction receiving unit. If a fax switch instruction is received through 920, it is a component for switching to a call between the outgoing fax 940-1 and the fax gateway 935.

11 is a block diagram showing another example of the configuration of the IP-based private exchange according to the present invention.

Referring to FIG. 11, the IP-based private exchange 950 according to the present invention may include a call signaling unit 960, a fax number database 970, and a controller 980. Another configuration example of the IP-based private exchange according to the present invention illustrated in FIG. 11 illustrates a configuration example of the IP-based private exchange when the fax call switching method using the caller's telephone number according to the present invention described with reference to FIG. 9 is applied. It is.

The call signaling unit 960 is a component that is connected to at least one subscriber station telephone and the Internet network, and establishes a call between at least two of the subscriber station telephone, an outgoing fax and a fax gateway connected through the Internet network.

That is, the call signaling unit 960 is the same as the call signaling unit 910 illustrated in FIG. 10, and detailed description thereof will be omitted.

The fax number database 970 is a component that stores a telephone number corresponding to at least one external fax apparatus, and may be a component included in the IP-based private exchange 950 according to the present invention, and is connected by wire or wireless. It may be a database existing in a separate database server (eg, connected to the Internet).

That is, although the fax number database 970 is illustrated as an internal component of the IP-based private exchange 950 in FIG. 11, even when the database exists in a separate database server connected by wired or wireless connection (eg, through an Internet network). It may be included in the embodiment of the IP-based private exchange according to the present invention.

Finally, the control unit 980 extracts the telephone number of the outgoing fax from the voice-over-IP call request to the subscriber station telephone from the outgoing fax 940-1 through the call signaling unit 960, The telephone number of the outgoing fax is queried from the fax number database 980, and if the telephone number of the outgoing fax is present in the fax number database 980, the call request for the subscriber station's telephone is the receiver. A component that sets up a call between an outgoing fax and the fax gateway.

5) How to transfer fax on voice-over-IP phone

The operating environment of the voice-over-IP telephone according to the present invention is the same as that of the IP-based private exchange described above with reference to FIG. 6. That is, the fax call transfer method of the voice-over-IP phone according to the present invention corresponds to the fax call transfer method of the IP-based private exchange described with reference to FIGS. 7 to 9, and the IP illustrated in FIGS. Corresponds to the operation method of voice-over-IP telephone interoperating with the base private exchange.

The fax call transfer method of the voice-over-IP telephone according to the present invention may be composed of two embodiments: a method of using a fax call transfer instruction by a user, and a method of using an automatic fax call transfer instruction using a caller ID. .

Hereinafter, the above-described two embodiments will be described with reference to the conceptual diagram of FIG. 6.

How to Use Fax Transfer Instruction by User

12 is a flowchart illustrating an embodiment of a fax call transfer method of a voice-over-IP telephone according to the present invention.

12, the fax call switching method of the voice-over-IP telephone according to the present invention includes a call signaling step (S1010), a voice signal processing step (S1020), a switch instruction input step (S1030), and a fax call switch instruction step. It may be configured to include (S1040).

In the call signaling step S1010, the voice-over-IP telephone 720-1 according to the present invention is connected to the IP-based private exchange 710 as a subscriber station telephone, from the outgoing faxes 740-1 and 740-2. Receiving a call request according to the voice-over-IP protocol and performing a call establishment procedure for the subscriber station.

That is, the call signaling step S1010 may include one of a plurality of subscriber station telephones 720-1 to 720-N (eg, 720-1) and an outgoing fax 740-1 connected to the IP-based private exchange 710. 740-2), a VoIP call is established through a procedure based on a VoIP protocol such as an H.323 protocol or a SIP protocol.

The VoIP protocol includes H.323, SIP, MGCP, and MEGACO, and the call signaling step S1010 may perform a call signaling procedure using at least one of various protocols as described above.

Next, the voice signal processing step S1020 is performed from a call established between the outgoing fax (e.g., 740-1) and the voice-over-IP phone 720-1 according to the present invention by the call signaling step S1010. Receiving a series of voice signal packets to convert the voice signal and outputs through the speaker.

At this time, the 'voice signal packet' is a packet containing voice signal data compressed according to standards such as G.711, G.723, G729 (eg, RTP-Realtime Transport Protocol packet, more precisely RTP / UDP / IP packet). Therefore, the voice signal processing step S1020 extracts and decodes the voice signal data portion from the received voice signal packet and outputs the sound of the voice call to the speaker when the established call is a voice call, or when the established call is a fax call, outgoing. The fax signal generated from the fax 740-1, that is, the fax tone, is output to the speaker.

In other words, if the established call is a voice call, the received voice signal packet is a packet in which a voice signal is encoded and is reproduced through a speaker. If the established call is a fax call, the received voice is received. Since the signal packet is a voice signal packet in a form in which the fax signal is treated as a voice signal and encoded, the fax tone will be reproduced through the speaker. Thus, the user can distinguish between a voice call and a fax call through the sound reproduced through the speaker.

Next, when the user hears the sound output through the speaker through the voice signal processing step (S1020) and confirms that the fax tone signal is included, the switching instruction input step (S1030) receives an instruction to send a fax call from the user. Step.

In this case, the switching instruction input may be configured to be input from the user through at least one input device among a button, a touch pad, and a touch screen included in the voice-over-IP telephone according to the present invention.

Finally, if the fax call transfer instruction step (S1040) receives a fax call transfer instruction from the user in the switch instruction input step (S1030), it is determined that the call established through the call signaling step (S1010) is a fax call A fax call transfer instruction is sent to the private exchange 710.

At this time, the 'fax call switching instruction' may be made by the message transfer between the voice-over-IP telephone 720-1 and the private exchange 710 according to the present invention. For example, a SIP message or an existing SIP message (eg, voice-over-IP telephone) separately defined in the voice-over-IP telephone 720-1 and the private exchange 210 according to the present invention is transferred to a private exchange. Defining a certain field in the message to be sent to request a message or by including a predetermined indication value in an existing field, so that the subscriber station telephone 720-1 transmits a message to the private exchange 710. May be configured to convey an indication. For example, in the voice call over fax method of the voice-over-IP telephone according to the present invention, an example of a SIP message used to transmit a fax call change indication may be the same as the SIP message illustrated in FIG. 8.

Meanwhile, when the voice-over-IP telephone according to the present invention transmits the 'fax call transfer instruction' to the IP-based private exchange 710, the IP-based private exchange 710 is the present invention. Set the call established between the voice-over-IP telephone 720-1 and the outgoing fax 740-1 to the fax call between the outgoing fax 740-1 and the fax gateway 735, and receive fax operation at the fax gateway. This facsimile call transfer and facsimile reception step (S1050) is performed. The fax call transfer and fax reception operations are operations of a conventional private exchange and a fax gateway, and thus detailed description thereof will be omitted.

When the switch instruction from the user is not input in the switch instruction input step S1030, the process proceeds to the normal voice call processing step S1035. A detailed description of the conventional voice call processing step (S1035) will be omitted, but since the 'fax call switch instruction' is not transmitted to the IP-based private exchange 710, the subscriber station telephone is recognized as a normal voice call in this case. The call of 720-1 and the calling station (in this case the calling station will not be a fax machine) will continue.

How to Use Fax Transfer Instruction Using Caller ID

FIG. 13 is a flowchart illustrating another embodiment of a fax call transfer method of a voice-over-IP telephone according to the present invention.

Referring to FIG. 13, another embodiment of the method for fax call switching of a voice over IP phone according to the present invention includes a call request receiving step (S1110), a fax call determining step (S1120), and a fax call switching command step (S1130). It can be configured to include.

In step S1110, the voice-over-IP telephone 720-1 according to the present invention is connected to the IP-based private exchange 710 as a subscriber station telephone, and the outgoing faxes 740-1 and 740-2. Receiving a call request according to the voice-over-IP protocol from the terminal and performing a call establishment procedure for the subscriber station.

The VoIP protocol includes H.323, SIP, MGCP, and MEGACO, and the call request receiving step S1110 may perform a call signaling procedure using at least one of various protocols as described above.

Next, the fax call determination step (S1120) determines whether the caller ID (CID) identified in the call request reception step (S1110) is the same as one of the telephone numbers corresponding to the at least one stored fax machine. And if the caller's telephone number is the same as one of the telephone numbers of at least one fax device registered in advance, determining that the incoming call is a fax call.

The voice-over-IP telephone 720-1 according to the present invention interprets a call request message such as a Q.931 Setup message according to the H.323 protocol or an INVITE message according to the SIP protocol, and uses a caller ID (CID: Caller ID). ) Can be checked. In other words, it searches the phone book where the verified caller's phone number is stored in advance with the phone numbers of the external fax machines to search whether the caller's phone number is registered as a 'fax device', and the caller's phone number is a fax. In the case of the telephone number of the device, it may be configured to determine that the incoming call is a fax call.

Finally, in the case of determining that the requested call is a fax call in the fax call determination step (S1120), the fax call switching instruction step (S1130) is a step of transmitting a fax call switching instruction to the IP-based private exchange 710.

At this time, the 'fax call switching instruction' may be made by the message transfer between the voice-over-IP telephone 720-1 and the private exchange 710 according to the present invention. For example, a predetermined field may be defined in a SIP message or an existing SIP message defined separately in the voice-over-IP telephone 720-1 and the private exchange 710 according to the present invention, or a predetermined indication value may be set in the existing field. The subscriber station telephone 720-1 can be configured to convey a 'fax call transfer indication' by sending a message to the private exchange 710. Since a specific example of the SIP message that can be used for the 'fax call change indication' is illustrated in FIG. 8, a detailed description thereof will be omitted.

Meanwhile, when the voice-over-IP telephone according to the present invention transmits the 'fax call transfer instruction' to the IP-based private exchange 710, the IP-based private exchange 710 is the present invention. Fax call transfer to set the call requesting the voice-over-IP telephone 720-1 to the recipient as a fax call between the outgoing fax 740-1 and the fax gateway 735 and to perform a fax reception operation at the fax gateway. And a fax reception step (S1140).

If it is determined in the fax call determination step (S1120) that the incoming call is not a call originating from the fax machine, the process proceeds to the normal voice call processing step (S1125). The detailed description of the conventional voice call processing step (S1125) will be omitted, but since the 'fax call switch instruction' is not transmitted to the IP-based private exchange 710, in this case, the subscriber station telephone is recognized as a normal voice call. A voice call processing procedure will be performed in which a call is established between 220-1 and the originating station (in which case the originating station will not be a fax machine).

As described above, the difference between a method of using a fax call transfer instruction by a user and a method of using a fax call transfer instruction using a calling party number is different from the voice-over-IP telephone 720-1 and the calling station ( 740-1) whether a voice call is established once.

That is, in the case of a method for using a fax call switching instruction by a user, a call is established between the outgoing fax 740-1 and the telephone 720-1 according to the present invention, and the established call is a fax call. A call between the telephone 720-1 and the outgoing fax 740-1 is transferred to the call between the outgoing fax 740-1 and the fax gateway 735 by receiving a fax transfer instruction by the user sensed by this sound. Will switch.

On the other hand, in the case of the method using the call forwarding instruction using the caller ID, the caller does not establish a call between the outgoing fax 740-1 and the telephone 720-1, and analyzes only the call request message to determine only the caller ID. Instead of establishing a call between subscriber station telephone 720-1 and outgoing fax 740-1, the call is transferred to the call between outgoing fax 740-1 and fax gateway 735.

Meanwhile, the above two methods are not used exclusively, but the above two methods may be applied together to constitute a fax call switching method of the voice-over-IP telephone according to the present invention. For example, when a call request is received from the outside, the caller may operate by checking the calling party number by the latter method, and then switch to the former method when the calling party number does not exist in the registered phone book.

On the other hand, since the operation related to the fax gateway 735 that operates in conjunction with the IP-based private exchange according to the present invention has been described above is omitted.

6) Fax Transfer Function Voice-over-IP Phone Configuration

14 is a block diagram showing an example of the configuration of a voice-over-IP telephone according to the present invention.

Referring to FIG. 14, the voice-over-IP phone 1000 according to the present invention may include a call signaling unit 1010, a voice signal processing unit 1020, an input device 1030, and a controller 1040. have. One configuration example of the voice-over-IP phone according to the present invention illustrated in FIG. 14 is a voice-over-IP phone when a method using a fax call transfer instruction by a user according to the present invention described with reference to FIG. 12 is applied. An example of the configuration is shown.

The call signaling unit 1010 is a component connected to the IP-based private exchange 710 to perform a voice-over-IP call setup procedure.

As mentioned above, the call signaling unit 1010 may perform a call signaling procedure using at least one of various VoIP protocols such as H.323, SIP, MGCP, and MEGACO.

The voice signal processor 1020 is a component that receives a series of voice signal packets from a call established by the call signaling unit 1010, converts the voice signal packets into voice signals, and outputs them through a speaker. That is, the voice signal processing unit 1020 extracts and decodes the voice signal data portion from the received voice signal packet and outputs the sound of the voice call to the speaker when the established call is a voice call, or when the established call is a fax call, outgoing fax. A component that outputs a fax signal, i.e., a fax tone, generated from a speaker.

In detail, the voice signal processing unit 1020 is indirectly connected to the Internet network 1030 through an IP private exchange 710 to receive a series of voice signal packets from a call established by the call signaling unit 1010. It may include a packet receiving unit 1021, a voice processing unit 1022 for extracting, decoding and reproducing a voice signal data portion from a series of voice signal packets, and a speaker 1023 for outputting a voice signal. .

That is, the packet receiver 1021 may be configured to include an Ethernet controller connected through an RJ-45 terminal connected to an UTP cable introduced into the outside. Alternatively, the packet receiver may be configured as a terminal device of an optical subscriber network such as GE-PON and WDM-PON represented by FTTH (Fiber To The Home). Similarly, it is possible to receive voice signal packets (eg, RTP packets) transmitted from the outside by being connected to the Internet network through a cable modem, AdSL, VdSL, PLC, or the like.

The voice processing unit 1022 is a component that extracts, decodes, and reproduces a voice signal data portion from a series of voice signal packets received from the packet receiving unit 1020 to reproduce it as a voice signal.

The input device 1030 is a component that is instructed to receive a fax call from a user, and is composed of a keypad, a touch pad, a touch screen, and the like, and presses a specific key, selects a specific soft key, The touch operation may be recognized as a fax call change instruction command from the user.

Finally, when the control unit 1040 is instructed to switch the fax call from the user through the input device 1030, the controller 1040 determines that the call set through the call signaling unit 1010 is a fax call to the IP-based private exchange 710 It is a component that transmits a 'fax call change indication' through the signaling unit 1010.

In this case, the 'fax call transfer instruction' may define a predetermined field in a SIP message or an existing SIP message that is separately defined between the voice-over-IP telephone 1000 and the private exchange 710 according to the present invention, or a predetermined field in the existing field. Including the indication value, the voice-over-IP telephone 1000 can be configured to deliver a 'fax call transfer indication' by sending a message to the private exchange 710.

Fig. 15 is a block diagram showing another configuration example of the voice-over-IP telephone according to the present invention.

Referring to FIG. 15, the voice-over-IP telephone 1100 according to the present invention includes a call signaling unit 1110, a fax number database 1120, a fax call determination unit 1130, and a controller 1140. Can be. Another configuration example of the voice-over-IP telephone according to the present invention illustrated in FIG. 15 is a voice-over-IP when a method of using a fax call transfer indication using a caller ID according to the present invention described with reference to FIG. 13 is applied. The configuration example of the telephone is shown.

The call signaling unit 1110 is connected to an IP-based private exchange 710 and is a component that receives a requested voice-over-IP call request from an external originating station and performs a call establishment procedure. As mentioned above, the call signaling unit 1110 may perform a call signaling procedure using at least one of various VoIP protocols such as H.323, SIP, MGCP, and MEGACO.

Next, the fax number database 1120 is a component that stores telephone numbers corresponding to at least one external originating fax apparatus. The fax number database 1120 may be a component included in the voice-over-IP telephone 1100 according to the present invention. The fax number database 1120 may be a database existing in a separate database server connected by wire or wireless connection (for example, through an Internet network). Can be.

That is, in FIG. 15, although the fax number database 1120 is illustrated as an internal component of the voice-over-IP phone 1100, the database exists in a separate database server connected through a wired or wireless connection (eg, through an Internet network). Even the case may be included in the embodiment of the voice-over-IP telephone according to the present invention.

The fax call determination unit 1130 determines whether the caller ID (CID) identified by the call signaling unit 1110 is the same as one of the telephone numbers corresponding to the fax device stored in the fax number database 1120. And when the caller's telephone number is the same as one of the telephone numbers of at least one fax device registered in advance, it is an element for determining that the call being set or set is a fax call.

That is, the fax call determination unit 1130 interprets a call request message such as a Q.931 Setup message according to the H.323 protocol or an INVITE message according to the SIP protocol, and checks a caller ID (CID: Caller ID). If the caller's telephone number is the telephone number of the fax machine, it can be determined that the incoming call is a fax call.

Lastly, when the call received by the fax call determination unit 1130 determines that the call is a fax call, the control unit 1140 determines that the call set up through the call signaling unit 1110 is a fax call and is based on the IP-based private exchange 710. ) Is a component that transmits a 'fax call change indication' through the call signaling unit 1110.

In this case, the 'fax call transfer indication' may define a predetermined field in a SIP message or an existing SIP message separately defined between the voice-over-IP telephone 1110 and the private exchange 710 according to the present invention, or a predetermined field in the existing field. Including the indication value, the voice-over-IP phone 1110 may be configured to convey a 'fax call transfer indication' by sending a message to the private exchange 710.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

1A and 1B are conceptual views for explaining examples of a method of receiving a fax through the Internet and a public telephone network.

Figure 1c is a conceptual diagram illustrating the configuration of the IP-based private switching network according to the prior art.

2 is a conceptual diagram illustrating an operating environment of a voice-over-IP telephone according to the present invention.

3 is a flowchart illustrating a fax reception method through a voice-over-IP telephone according to the present invention.

4 is a conceptual diagram illustrating a fax reception and processing step applied to a fax reception method through a voice-over-IP telephone according to the present invention.

Fig. 5 is a block diagram showing a configuration example of a fax reception function voice-over-IP telephone according to the present invention.

6 is a conceptual diagram illustrating an operating environment of an IP-based private exchange according to the present invention.

7 is a flowchart illustrating an embodiment of a fax call switching method of an IP-based private exchange according to the present invention.

8 is a conceptual diagram illustrating an example of a SIP message used to receive a fax call switch instruction in a fax call switch method of an IP-based private exchange according to the present invention.

9 is a flowchart illustrating another embodiment of a fax call switching method of an IP-based private exchange according to the present invention.

10 is a block diagram illustrating an example of a configuration of an IP-based private exchange according to the present invention.

11 is a block diagram showing another example of the configuration of the IP-based private exchange according to the present invention.

12 is a flowchart illustrating an embodiment of a fax call transfer method of a voice-over-IP telephone according to the present invention.

FIG. 13 is a flowchart illustrating another embodiment of a fax call transfer method of a voice-over-IP telephone according to the present invention.

14 is a block diagram showing an example of the configuration of a voice-over-IP telephone according to the present invention.

Fig. 15 is a block diagram showing another configuration example of the voice-over-IP telephone according to the present invention.

Claims (28)

Transferring the voice-over-IP call from the calling fax device to the receiving voice-over-IP phone; Receiving a message containing information indicating that the voice-over-IP call is a fax call from the receiving voice-over-IP phone; And And operating the fax call to an external fax processing device. The method of claim 1, wherein the message further comprises information of the originating fax machine and information of the receiving voice-over-IP telephone. The method of claim 2, wherein the message is a message supported by an H.323 protocol or a Session Initiation Protocol (SIP) protocol. The method of claim 1, wherein the recipient voice-over-IP telephone information is transmitted to the external fax processor in the step of forwarding the fax call to an external fax processor. 5. The method of claim 4, wherein in the step of transmitting the fax call to an external fax processing device, information on the receiver voice-over-IP telephone is generated by transmitting DTMF tones. The method according to claim 1 or 4, wherein the external fax processing device is a fax gateway. The method of claim 1, wherein the fax call is a fax call supported by an H.323 protocol, a Session Initiation Protocol (SIP) protocol, a Media Gateway Control Protocol (MGCP) protocol, or a Media Gateway Control Protocol (MEGACO) protocol. How to operate the IP private exchange. Checking whether the voice-over-IP call received from the calling fax machine is a fax call; Forwarding the fax call to an external fax processor when the voice-over-IP call is confirmed as a fax call; And And transmitting the fax packet data for the fax call to the external fax processing device when the fax call is set up between the calling fax machine and the external fax processing device. 9. The method of claim 8, wherein in the step of delivering the fax call to an external fax processing device, fax recipient information is transferred to the external fax processing device. The operation of the IP private exchange according to claim 9, wherein, in the step of transmitting the fax call to an external fax processing device, the fax receiver information transmits information of a receiver voice-over-IP telephone by generating DTMF tones. Way. The method according to any one of claims 8 to 10, wherein the external fax processing device is a fax gateway. The method of claim 8, wherein the fax call is a fax call supported by an H.323 protocol, a Session Initiation Protocol (SIP) protocol, a Media Gateway Control Protocol (MGCP) protocol, or a MEGACO (Media Gateway Control Protocol) protocol. How to operate the IP private exchange. The method of claim 8, wherein the step of confirming whether the voice-over-IP call is a fax call is confirmed through information on the calling fax machine. 15. The method of claim 13, wherein the step of checking whether the voice-over-IP call is a fax call is performed by comparing a telephone number of a pre-stored fax machine with a telephone number of the calling fax machine. . 9. The method of claim 8, wherein the step of checking whether the voice-over-IP call is a fax call is performed through a message transmitted from a received voice-over-IP phone. A call signaling unit for transferring a voice-over-IP call from a calling fax device to a receiving voice-over-IP telephone; A message receiving unit for receiving a message including information indicating that the voice-over-IP call is a fax call from the receiving voice-over-IP phone; And And a control unit which transfers the fax call to an external fax processing device. 17. The IP private exchange as claimed in claim 16, wherein the message further comprises information of the originating fax machine and information of the receiving voice-over-IP telephone. 18. The IP private exchange of claim 17, wherein the message is a message supported by an H.323 protocol or a Session Initiation Protocol (SIP) protocol. 17. The IP private exchange as claimed in claim 16, wherein the control unit transmits the information of the receiver voice-over-IP telephone to the external fax processing apparatus when the fax call is transmitted to the external fax processing apparatus. 20. The IP private exchange as claimed in claim 19, wherein the control unit generates and transmits information of the receiver voice-over-IP telephone through DTMF tones when transmitting the fax call to an external fax processing apparatus. A control unit which checks whether the voice-over-IP call received from the calling fax machine is a fax call and delivers the fax call to an external fax processing apparatus when the voice-over-IP call is confirmed as a fax call; And And a call signaling unit for transmitting the fax packet data for the fax call to the external fax processor when the fax call is set up between the calling fax machine and the external fax processor. 22. The IP private exchange as claimed in claim 21, wherein the control unit transmits the fax receiver information to the external fax processing device when the fax call is transmitted to the external fax processing device. 23. The IP private exchange as claimed in claim 22, wherein, when the control unit transmits the fax call to an external fax processing device, the fax receiver information transmits information of a receiver voice-over-IP telephone by generating DTMF tones. . 25. The IP private exchange as claimed in any one of claims 21 to 24, wherein the external fax processing device is a fax gateway. 22. The method of claim 21, wherein the fax call is a fax call supported by an H.323 protocol, a Session Initiation Protocol (SIP) protocol, a Media Gateway Control Protocol (MGCP) protocol, or a Media Gateway Control Protocol (MEGACO) protocol. IP private exchange. 22. The IP private exchange as claimed in claim 21, wherein the controller checks whether the voice-over-IP call is a fax call through the information on the calling fax machine. 27. The IP private exchange as claimed in claim 26, wherein the controller checks whether the voice-over-IP is a fax call by comparing a telephone number of a fax machine previously stored with a telephone number of the calling fax machine. 22. The IP private exchange as claimed in claim 21, wherein the controller checks whether the voice-over-IP call is a fax call through a message transmitted from a received voice-over-IP phone.

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