WO2001058101A1

WO2001058101A1 - An internet telephone implement method using internet telephone interface utility and ip

Info

Publication number: WO2001058101A1
Application number: PCT/KR2000/000254
Authority: WO
Inventors: Myoung Tak Han
Original assignee: Hyuntel Telecom Co., Ltd.
Priority date: 2000-02-03
Filing date: 2000-03-23
Publication date: 2001-08-09
Also published as: KR100386930B1; AU3461600A; KR20010025616A

Abstract

The subject invention relates to an Internet telephone interfacing device; a method for realization of Internet telephone call between external telephone and external terminal, wherein audio signals received by said external terminal are outputted by receiver of said external telephone and audio signals received by said external telephone are inputted in audio input unit of said external terminal; and a method for realization of Internet telephone call using IP, wherein direct telephone call via the Internet is possible without intervention of an Internet telephone server, by storing IP numbers of a plurality of terminals in a database and providing desired IP number from said database upon request of a terminal.

Description

A INTERNET TELEPHONE IMPLEMENT METHOD USING INTERNET TELEPHONE INTERFACE UTILITY AND IP

Technical Field of the Invention

The present invention generally relates to an Internet telephone, and in particular to an Internet telephone interfacing device using an external telephone and a method for realizing an Internet telephone call using an Internet protocol (IP).

Background of the Invention

A variety of appliances employing multimedia and information processing techniques associated with the multimedia have recently been introduced due to the development of computer and communication techniques. Further, the Internet. interconnecting the distant corners of the globe, has rapidly gained popularity and realized recently long-distance telephone call over it. This telephone call over the Internet can provide call connections over the Internet without using an existing telephone network. In other words, such an Internet telephone service comprises a system implemented to interconnect a personal computer (PC) equipped with a software (SW) for Internet telephone, speaker, a microphone and a sound card, and another PC having the same construction over the Internet and allow users of those two PCs to make telephone calls over the Internet like over a general telephone. This Internet telephone service, after having been first provided by Vocaltec of Israel, in February 1995. has thereafter rapidly spread throughout the world and gradually developed from the initial PC-to-PC mode to a PC-to-telephone mode, and further to telephone-to-telephone mode.

The above Internet telephone service, despite its disadvantages in speech quality inferior to that of a general telephone service and in the fact that a service subscriber can make a telephone call to another service subscriber only when the latter' s computer is at online standby state, is now rapidly spreading due to its advantages in that it can provide an International telephone call at low cost and enables also simultaneous digital transmission of multimedia data such as image, document, etc.

Fig. 1 shows an architecture of a conventional Internet telephone system, in which the reference numerals 1 18 and 120 denote Internet service providers (ISPs) which provide a basic service for connecting PCs 102 and 130 of users A 100 and B 128 to the Internet 1 16, respectively. The Internet service providers 1 18 and 120 may be, for example, enterprises such as Hitel, Unitel and Nownuri in Korea. The reference numerals 122 and 124 denote servers that provide an Internet telephone service. The servers 122 and 124 may be, for example, Internet telephone companies such as Dialpad and Greathuman in Korea. Each of the servers 122 and 124 provides a service for establishing a telephone call between PCs connected thereto or a service for establishing a telephone call between a PC connected thereto and a telephone of another party over a telephone network 1 12. The reference numeral 126 denotes an Internet telephony gateway which converts Internet protocol (IP) packet data from each of the Internet telephone companies 122 and 124 into data of a format utilizable in the telephone network 1 12 and transfers the converted data to an exchange 1 14, converts data from the exchange 1 14 into IP packet data and transfers the converted IP packet data to the Internet telephone company 122 or 124. A description of the establishment of a telephone call between the users A 100 and B 128 is given below with reference to Fig. 1. The user A 100 can make a telephone call with the user B 128 via a plurality of paths such as L1-L3. The first path LI is a telephone-to-telephone path where the user A 100 can converse with the user B 128 over an exchange and telephone network, and the second path L2 is a PC- to-telephone path where the user A 100 can access an ISP server on the Internet using a computer with a microphone and speaker and then converse with the user B 128 through an Internet telephone company server. The third path L3 is a PC-to-PC path where the user A 100 can make a telephone conversation with the user B 128 through an Internet telephone company server. Alternatively, a direct telephone call may be established between PCs of the users A 100 and B 128 connected to the Internet using IP addresses without intervention of an Internet telephone company.

A detailed description of the establishment of Internet telephone calls based on the above second and third paths L2 and L3 is given in the following:

A conventional PC-to-PC Internet telephone method based on the third path L3 functions in a manner that two users desiring telephone calls with each other simultaneously connect to the Internet and make telephone calls to the other through an Internet telephone server of Vocaltec or Dialpad. A PC of the speaking user digitizes an analog audio signal from a microphone, compresses the resultant digital audio signal, packets the compressed audio signal according to a protocol such as H323, RSVP or RTP/RTCP and sends the resultant audio packet data to a PC of the listening user on a packet basis over the Internet. Then, the PC of the listening user expands the received audio packet data to the original state, converts the resultant digital packet data into an analog audio signal and outputs the converted analog audio signal to a speaker so that the listening user can hear the voice of the speaking user. A conventional PC-to-telephone Internet telephone method based on the second path L2 functions in a manner that a calling user installs an associated program in his PC, connects to the Internet and sends a calling signal to a general telephone of a called user over a telephone network by virtue of an Internet telephony gateway installed in a specific region. The called user makes a telephone conversation over the general telephone, whereas the calling user makes a telephone call in the same manner as the above PC-to-PC method. As a result, the PC-to-telephone method can be considered as improved compared with the PC-to-PC method. Namely, while the PC- to-PC method is performed fully depending on the Internet, the PC-to-telephone method is performed partially depending on the Internet in such a manner that the calling user makes a telephone call over the Internet and the called user makes a telephone conversation over the existing telephone network. Here, the Internet telephony gateway functions to interconnect the Internet and the existing telephone network.

However, each user must utilize a speaker and microphone connected to a PC sound card as shown in Fig. 1 in order to use a conventional Internet telephone service based on the PC-to-PC method or PC-to-telephone method as described in above referenced Fig. 1. That is, for utilization of the conventional Internet telephone service, each user must be positioned near his PC to talk over the microphone and listen from the speaker. Further, in order to receive the voice under a more stable condition, each user has to wear a headphone equipped with a microphone, which is inconvenient in use. On the other hand, there is up to the present no service providing the IP address of a called party for establishing an IP address-based Internet telephone call. Accordingly, a calling party must know the IP address of the called party in order to make a telephone call with the called party over the Internet. The case where a called party has a fixed IP address is less problematic because the IP address is maintained. On the contrary, in the case where a called party has a variable IP address as for an ADSL user, it is difficult to establish an IP address-based Internet telephone call because the IP address varies for each connection to an ISP. Detailed Description of the Invention

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an Internet telephone interfacing device and method for establishing an Internet telephone call using an external telephone. It is another object of the present invention to provide a method for realizing an

Internet telephone call using an Internet protocol, in which the Internet telephone call is easily established according to an Internet protocol address of a called party, provided from an Internet protocol server.

In accordance with the present invention, the above and other objects can be accomplished by a provision of an Internet telephone interfacing device which is capable of transferring an audio signal from an external terminal unit connected to an external telephone to a receiver of the external telephone and an audio signal from the external telephone to an audio input terminal of the external terminal unit, respectively, thereby realizing an Internet telephone call using the external telephone. For realizing an Internet telephone call using the Internet protocol in accordance with the present invention, Internet protocol numbers of a plurality of terminal units connected to the Internet are stored in a database and, when the Internet protocol number of a specific terminal unit is requested by a different terminal unit, it is searched from the database and provided to the different terminal unit. In this way, the present invention enables to realize an Internet telephone call using the Internet protocol without intervention of an Internet telephone company.

Brief Description of the Drawings

The above and other objects, features and advantages of the present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a view showing the architecture of a conventional Internet telephone system; Fig. 2 is a view showing the architecture of an Internet telephone system in accordance with the preferred embodiment of the present invention;

Fig. 3 is a block diagram showing the construction of an Internet telephone interfacing device in accordance with the preferred embodiment of the present invention; Fig. 4 is a view showing the architecture of an Internet protocol server system in accordance with the preferred embodiment of the present invention;

Fig. 5 is a flowchart illustrating a procedure for setting up initial environments of the Internet telephone interfacing device in accordance with the preferred embodiment of the present invention; Fig. 6 is a flowchart illustrating an office line telephone mode operation of the

Internet telephone interfacing device in accordance with the preferred embodiment of the present invention;

Figs. 7a and 7b are flowcharts illustrating an Internet telephone mode operation of the Internet telephone interfacing device in accordance with the preferred embodiment of the present invention; Fig. 8 is a view showing a main menu picture of an application program for the Internet telephone interfacing device in accordance with the preferred embodiment of the present invention;

Fig. 9 is a view showing an initial environment setup picture of the application program for the Internet telephone interfacing device in accordance with the preferred embodiment of the present invention;

Fig. 10a is a block diagram of an Internet telephone call processor in Fig. 3; and Fig. 10b is a block diagram of an office line telephone call processor in Fig. 3.

Description of the Preferred Embodiment

For convenience of the description and a better understanding of the present invention, same elements are indicated by the same reference numeral even though they are depicted in different drawings. Further, in the following description made in conjunction with the preferred embodiment of the present invention, a variety of specific details are shown to provide a more general understanding of the present invention. However, those skilled in the art will appreciate that the present invention can be implemented without relying on the above-mentioned specific details. In the following description of the present invention, a detailed description of the publicly known functions and constructions incorporated herein is omitted in order that the subject matter of the present invention appears more clear.

Fig. 2 is a view showing the architecture of an Internet telephone system in accordance with the preferred embodiment of the present invention. As shown in this drawing, Internet telephone interfacing devices 200 are installed between external telephones 108 and 136 and PCs 102 and 130 of users, respectively, to establish Internet telephone calls using the external telephones 108 and 136 instead of microphones and speakers, which have been conventionally required to be installed in the PCs to make Internet telephone calls. The Internet telephone interfacing device 200 is adapted to transfer a calling or called user's audio signal from a transmitter of the associated external telephones 108 and 136 to a microphone signal input terminal of the associated PCs 102 and 130. The Internet telephone interfacing device 200 is further adapted to transfer a called or calling user's audio signal received by the associated PC to a receiver of the associated external telephone. Therefore, an Internet telephone call can be realized using an external telephone like by a general telephone without using a microphone and speaker installed in a PC as in the conventional method.

Fig. 3 is a block diagram showing the construction of the Internet telephone interfacing device 200 in the Internet telephone system in accordance with the preferred embodiment of the present invention. In this drawing, the reference numeral 312 denotes a first relay which forms a speech line between the external telephone 108 and an office line in an office line telephone mode, and which is switched under control of a controller 308 to connect the external telephone 108 to the Internet through an Internet telephone call processor 302 in an Internet telephone mode. A second relay 314 is switched under the control of the controller 308 to output an audio signal from an external PC through an external speaker in the office line telephone mode, and transfers the audio signal from the external PC to a receiver of the external telephone 108 through the Internet telephone call processor 302 in the Internet telephone mode.

A third relay 316 is switched under the control of the controller 308 in such a manner that it is connected to an external microphone of the PC in the office line telephone mode to transfer an audio signal from the microphone to a microphone signal input terminal of the PC, and connected to the Internet telephone call processor 302 in the Internet telephone mode to transfer an audio signal from a transmitter of the external telephone 108 to the microphone signal input terminal of the PC. A fourth relay 318 is switched under the control of the controller 308 to connect an office line telephone call processor 304 to a dual tone multifrequency (DTMF) detector 306 in the office line telephone mode and the Internet telephone call processor 302 to the DTMF detector 306 in the Internet telephone mode. The DTMF detector 306 functions to detect a dial number from a dial key of the external telephone 108 and applies it to the controller 308. In any case, the Internet telephone call processor 302 includes, as shown in Fig.

10a, a subscriber line interface circuit (SLIC) 321 for interfacing the external telephone 108 with a subscriber line, an office line call termination alarm generator 322 for generating an alarm to the user when an office line incoming call termination occurs while an Internet telephone call is established, a hook-off detector 324 for detecting a hook-off state of the external telephone 108 and notifying it to the controller 308, a call waiting tone generator 326 for generating a call waiting tone to the external telephone 108 as in an exchange when the external telephone 108 is at the hook-off state, and a ringer 320 for generating a ring tone to the external telephone 108 when an Internet incoming call termination occurs. The office line telephone call processor 304 includes in any case, as shown in Fig. 10b. an office line call termination detector 329 for detecting whether an office line incoming call termination occurs, an Internet call termination alarm generator 328 for generating an alarm to the external telephone 108 when an Internet incoming call termination occurs while an office line telephone call is established, and a hook-off detector 330 for detecting the hook-off state of the external telephone 108. A PC interface unit 310 is connected to the PC through a serial or parallel communication port to interface input/output data between the Internet telephone interfacing device 200 and the PC. The controller 308 is adapted to control the overall operation of the Internet telephone interfacing device 200 and store an operating program and various reference data. Further, the controller 308 includes a memory for temporarily storing data generated when the Internet telephone interfacing device 200 performs various operations according to the operating program.

Fig. 4 is a view showing the architecture of an Internet protocol (IP) server system for realization of an Internet telephone call using IP addresses in accordance with the preferred embodiment of the present invention. In the preferred embodiment, an IP server 408 updates variable IP addresses of a plurality of PCs 400, 402, 404 and 406 connected thereto via Internet service providers (ISPs) 1 18 and 120, and stores them in a lookup table 412 in a database (DB) 410. When one of the PCs 400-406 requests a current IP address of a desired one of the other PCs, the IP server 408 provides the requested IP address to said PC. Accordingly, for realization of an Internet telephone call using IP, concerned parties can be provided with each other's IP addresses from the IP server 408 without the need for authenticating each other's IP addresses. This can remove the conventional inconvenience resulting from the fact that concerned parties had to authenticate each other's IP addresses to make an Internet telephone call using IP. Fig. 5 is a flowchart illustrating a procedure of setting up initial environments of the Internet telephone interfacing device 200 in accordance with the preferred embodiment of the present invention.

First, if a user pushes a power-on key, then an associated PC is powered on at step 500. Thereafter, if the user requests connection to a desired ISPs 1 18 or 120, then the PC proceeds to step 502 to access the desired ISP and acquire a unique IP number therefrom. In the case where the user wishes to make an Internet telephone call using the external telephone 108 or 136 under the above condition, the PC executes an application program previously installed therein to operate the Internet telephone interfacing device 200. Then, the PC displays a main menu picture of the application program for the Internet telephone interfacing device 200 on a monitor at step 504.

Fig. 8 is a view showing an example of the main menu picture of the application program for said Internet telephone interfacing device 200. which displays on a screen of the PC monitor for control of the main operation of the device 200. On this main menu picture, the user can connect to a server of an Internet telephone company 122 or 124 such as Dialpad or Greathuman in Korea to make an Internet telephone call. Further, in order to make an Internet telephone call with a called party, the user can utilize an IP-based Internet telephone program such as NetMeeting to enter a telephone number or IP address of the called party without having previously connected to an Internet telephone company server. On the main menu picture of Fig. 8, an initial environment setup button 800 is a selection button for setting up initial environments of the Internet telephone interfacing device 200. An IP number update button 802 is a selection button for connecting to an IP relay server and updating telephone numbers and IP numbers of desired parties. The results updated by the IP number update button 802 are displayed in a telephone directory window 804 of the main menu picture. An external telephone/office line connection button 806 is a selection button for connecting an external telephone to an office line. An external telephone/Internet connection button 808 is a selection button for connecting the external telephone to the Internet. A telephone number enter window 810 is a section for entering a telephone number of a party with which the user wishes to make a telephone call over the Internet. An IP number enter window 812 is a section for entering an IP number of a party with which the user wishes to make a telephone call over the Internet. Hence, the user can make an Internet telephone call with a desired party by entering a telephone number or IP number of the desired party in the telephone number enter window 810 or IP number enter window 812 and then clicking a connection button 814. An IP search window 816 is a section for searching a specific party's IP number.

First, the user has to set up various initial environments of the Internet telephone interfacing device 200 in an initial environment setup picture of the main menu picture. That is, the user must select the initial environment setup button 800 on the main menu picture displayed at the above step 504 to set up a variety of initial environments of the application program for the Internet telephone interfacing device 200. In response to the selection of the initial environment setup button 800 on the main menu picture, the application program for the Internet telephone interfacing device 200 proceeds to step 506 to display the initial environment setup picture for the device 200.

Fig. 9 is a drawing showing an example of the initial environment setup picture of the application program for the Internet telephone interfacing device 200. As shown in this drawing, the initial environment setup picture for the Internet telephone interfacing device 200 is composed of a window 900 for setting a basic transmission path of an external telephone, a window 902 for setting a transmission path change code of the external telephone, a window 904 for setting a priority for connection of Internet telephone companies, and a window 906 for setting addition of an Internet telephone company. Therefore, the user can set up or change the initial environments of the Internet telephone interfacing device 200 by entering desired data in corresponding windows of the initial environment setup picture shown in Fig. 9. In other words, if the user sets the basic transmission path of the external telephone to the office line or Internet, then the application program proceeds to step 508 to receive the set transmission path and apply it to the Internet telephone interfacing device 200. In the case where the user sets the transmission path change code of the external telephone, the application program proceeds to step 510 to receive the set transmission path change code and apply it to the Internet telephone interfacing device 200. When the user sets the connection priority for the Internet telephone companies, the application program proceeds to step 512 to receive the set connection priority and apply it to the Internet telephone interfacing device 200. In the case where the user adds a new Internet telephone company, the application program proceeds to step 514 to receive information about the added Internet telephone company and apply it to the Internet telephone interfacing device 200. As described above, the user can personally select the desired initial environment setup items and apply them to the Internet telephone interfacing device 200. Although the preferred embodiment of the present invention discloses four initial environment conditions of the Internet telephone interfacing device 200, other initial environment conditions can also be set in the same manner as described above.

Fig. 6 is a flowchart illustrating an office line telephone mode operation of the Internet telephone interfacing device 200 in accordance with the preferred embodiment of the present invention, which is performed under the control of the controller 308 in Fig. 3. Now, the office line telephone mode operation of the Internet telephone interfacing device 200 will be described in detail with reference to Figs. 3. 5 and 6.

First, the controller 308 in the Internet telephone interfacing device 200 receives the initial environment conditions set in the initial environment setup procedure of Fig. 5 from the application program for the device 200 in the PC and discriminates an initial transmission path of the external telephone 108. If the initial transmission path of the external telephone 108 is set for the office line telephone mode at step 600, the controller 308 controls the first relay 312 to connect the external telephone 108 to the office line at step 602 and establishes a telephone call between said external telephone 108 and a telephone of a party connected to the office line at step 604. As a result, in the case where the user does not use the Internet telephone, he can make a telephone call with a party over the external telephone 108 connected to the office line through the first relay 312, in the same manner as the general telephone call. Thereafter, the controller 308 proceeds to step 606 to determine whether the external telephone 108 connected to the office line has completed the telephone call with the party. If the telephone call has been completed, then the controller 308 waits for an office line incoming call termination or Internet incoming call termination to occur in the office line telephone mode.

In the case where it is determined at step 608 that the Internet incoming call termination occurs while the office line telephone call is made over the external telephone 108. the controller 308 controls the office line telephone call processor 304 at step 610 to generate an alarm to the external telephone 108 to inform the user of the occurrence of the Internet incoming call termination. As a result, while making the office line telephone call over the external telephone 108, the user recognizes the occurrence of the Internet incoming call termination from the generated alarm and, if necessary, may put the office line telephone call to a standby state for a little while and receive the Internet telephone call. In order to put the office line telephone call to a standby state and receive the Internet telephone call, there is a need for the first relay 312 to switch the external telephone 108 from the office line to the Internet telephone call processor 302. To this end, the user enters a combination of dial keys as a transmission path change code for requesting the first relay 312 to switch the external telephone 108 from the office line telephone mode to the Internet telephone mode (i.e., from the office line to the Internet telephone call processor 302). As a result, the controller 308 controls the switching operation of the first relay 312 in response to the dial key combination entered by the user. Here, the dial key combination can be implemented in various ways according to the user's setting. For example, the dial key combination may have a form of "###" obtained by entering successively three times the dial key "#" or a form of "* * **" obtained by entering successively four times the dial key "*". In the case where it is determined at step 612 that the user enters no dial key combination for a change to the Internet telephone mode, the controller 308 returns to the above step 604 to inform the user of the occurrence of the Internet incoming call termination while performing the above steps 604-610. If it is determined at step 612 that the user enters a dial key combination for a change to the Internet telephone mode, the controller 308 proceeds to step 614 to switch the first relay 312 to an Internet connection terminal, or the Internet telephone call processor 302. to connect the external telephone 108 to the Internet. As a result, the user can make an Internet telephone conversation over the external telephone 108. and the controller 308 establishes an Internet telephone call between the external telephone 108 and a calling party connected over the Internet at step 616. Thereafter, in the case where the user enters a dial key combination for change to the office line telephone mode at step 618 or the Internet telephone call is completed at step 620, the controller 308 proceeds to step 622 to control the first relay 312 to connect the external telephone 108 to the office line. Figs. 7a and 7b are flowcharts illustrating an Internet telephone mode operation of the Internet telephone interfacing device 200 in accordance with the preferred embodiment of the present invention, which is performed under the control of the controller 308 in Fig. 3. Now, the Internet telephone mode operation of the Internet telephone interfacing device 200 is described below in detail with reference to Figs. 3, 5, 6 and 7:

First, in a similar manner to Fig. 6, the controller 308 in the Internet telephone interfacing device 200 receives the initial environment conditions set in the initial environment setup procedure of Fig. 5 from the application program for the device 200 in the PC and discriminates an initial transmission path of the external telephone 108. If the initial transmission path of the external telephone 108 is set to the Internet telephone mode at step 700. the controller 308 proceeds to step 702 to control the first relay 312 to connect the external telephone 108 to an Internet connection terminal, or the Internet telephone call processor 302. As a result, the user can make an Internet telephone conversation over the external telephone 108 with a party connected over the Internet. Namely, the user can make or receive an internet telephone call to or from the party connected over the Internet.

The user can make a telephone call to a called party connected over the Internet in the following manner. First, the user will pick up a handset of the external telephone 108 to make a telephone call over the Internet. At this time, the controller 308 detects a hook-off state of the external telephone 108 at step 706 and then controls the Internet telephone call processor 302 at step 708 to generate a call waiting tone to the external telephone 108 as in the office line telephone mode. As a result, the user will hear the generated call waiting tone and then enter dial keys. That is, upon hearing the generated call waiting tone, the user will dial a telephone number or IP number of a desired party as in the office line telephone mode. Alternatively, the user may enter a predetermined combination of dial keys for requesting the first relay 312 to switch the external telephone 108 from the Internet telephone mode to the office line telephone mode.

In the case where the user enters a combination of dial keys at step 710, the controller 308 stops the generation of the call waiting tone at step 712 and then controls the DTMF detector 306 at step 714 to detect dial numbers from the dial keys entered by the user.

If the dial numbers received from the external telephone 108 and detected by the DTMF detector 306 are numbers for requesting a change to the office line telephone mode at step 716, the controller 308 proceeds to step 718 to control the first relay 312 to connect the external telephone 108 to the office line and then repeats the office line telephone mode operation shown in Fig. 6.

On the other hand, in the case where the dial numbers detected by the DTMF detector 306 are values indicative of a telephone number of a called party, the controller 308 proceeds from step 720 to step 722 to automatically connects to a server of a specific Internet telephone company according to the priority given by the user in the initial environment setup procedure, among Internet telephone companies such as

Dialpad or Greathuman. Subsequently, the controller 308 requests a connection to the above telephone number of the specific Internet company server at step 724. Hence, the specific Internet telephone company server establishes an Internet speech path between the user and the called party of the requested telephone number at step 726 so that the user can make an Internet telephone conversation with the called party.

In the case where the dial numbers detected by the DTMF detector 306 are numbers indicative of an IP number of a called party, the controller 308 proceeds from step 730 to step 734 to connect directly to the called party over the Internet via the ISP 118 or 120 using the above IP number without intervention of any Internet telephone company. Then, the controller 308 proceeds to the above step 726 to establish an Internet telephone call between the user and the called party.

On the other hand, if an Internet incoming call termination occurs at step 704, the controller 308 proceeds to step 736 to control the Internet telephone call processor 302 to generate a ring tone. The user recognizes the occurrence of the Internet incoming call termination from the generated ring tone and will then hook off the external telephone 108. At this time, the controller 308 detects the hook-off state of the external telephone 108 at step 738, controls the Internet telephone call processor 302 at step 740 to stop the generation of the ring tone, and further establishes an Internet telephone call between a calling party and the user at step 742. Thereafter, the controller 308 proceeds to step 744 to determine whether the external telephone 108 connected to the Internet has completed the telephone call with the calling party. If the telephone call has been completed, the controller 308 waits for the occurrence of an Internet incoming call termination or office line incoming call termination in the Internet telephone mode.

In the case where it is determined at step 746 that an office line incoming call termination occurs while an Internet telephone call is made over the external telephone 108, the controller 308 controls the Internet telephone call processor 302 at step 748 to generate an alarm to the external telephone 108 so as to inform the user of the occurrence of the office line incoming call termination. Accordingly, the user recognizes while making an Internet telephone call over the external telephone 108 the occurrence of the office line incoming call termination from the generated alarm and, if necessary, may put the Internet telephone call to a standby state for a little while and receive an office line telephone call in the opposite manner to Fig. 6. In order to put the Internet telephone call to a standby state and receive the office line telephone call, the first relay 312 needs to switch the external telephone 108 from the Internet to the office line. To this end, the user enters a predetermined combination of dial keys as a transmission path change code in a similar manner to Fig. 6 and the controller 308 controls the switching operation of the first relay 312 in response to the dial key combination entered by the user.

In the case where it is determined at step 750 that the user enters no dial key combination for the change to the office line telephone mode, the controller 308 just informs the user of the occurrence of the office line incoming call termination while performing the above steps 742-748. If it is determined at step 750 that the user enters a dial key combination for the change to the office line telephone mode, the controller 308 proceeds to step 752 to switch the first relay 312 to an office line connection terminal so as to connect the external telephone 108 to the office line. As a result, the user can make an office line telephone conversation over the external telephone 108, and the controller 308 establishes an office line telephone call between the external telephone 108 and a calling party connected to the office line at step 754. Thereafter, in the case where the user enters a dial key combination for a change to the Internet telephone mode at step 756 or the office line telephone call is completed at step 758. the controller 308 proceeds to step 760 to control the first relay 312 to connect the external telephone 108 to the Internet.

Although the preferred embodiments of the present invention have been described above for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as described in the accompanying claims. For example, although the Internet telephone interfacing device has been installed between the external terminal unit and the telephone separately and externally of them, it may also be internally installed in the form of a card within the external terminal unit and similarly applied to the Internet telephone call realization method of the present invention. Accordingly, the scope of the rights of the subject invention shall not be determined by the descriptions of the embodiments herein, but rather by the accompanying claims and their equivalents.

Industrial Applicability

As described above, the present invention discloses an Internet telephone interfacing device which is capable of transferring an audio signal from an external terminal unit connected to an external telephone to a receiver of the external telephone and an audio signal from the external telephone to an audio input terminal of the external terminal unit, respectively. In this way, the present invention enables to realize an Internet telephone call using external telephone, making the use of a microphone and speaker conventionally installed in a PC unnecessary, thus, resulting in more convenience in use.

Another advantage of the present invention is that it enables to realize an Internet telephone call using the IP numbers of the connected terminal units without intervention of an Internet telephone company by storing IP numbers of a plurality of terminal units connected to the Internet in a database, and, when the IP number of a specific terminal units is requested by a different terminal unit, by searching it from the database and providing it to the different terminal unit.

Claims

What is claimed is:

1. An Internet telephone interfacing device for realizing an Internet telephone call using an external telephone, comprising: Internet telephone call processing means for transferring an audio signal from an external terminal unit to a receiver of said external telephone and an audio signal from said external telephone to an audio input terminal of said external terminal unit, respectively; office line telephone call processing means for detecting hook-off state of said external telephone and the occurrence of an office line incoming call termination; dual tone multifrequency detection means for detecting a dual tone multifrequency signal from a dial key of said external telephone; first switching means for selectively connecting said external telephone to an office line and the Internet; second switching means for selectively connecting an audio signal output terminal of said external terminal unit to said Internet telephone call processing means and an audio signal output circuit of said external terminal unit; third switching means for selectively connecting an audio signal input terminal of said external terminal unit to said Internet telephone call processing means and an audio signal input circuit of said external terminal unit; fourth switching means for selectively connecting said Internet telephone call processing means and office line telephone call processing means to said dual tone multifrequency detection means; control means for controlling said first switching means to connect said external telephone to said office line in an office line telephone mode and establish a speech line between said external telephone and Internet telephone call processing means in an Internet telephone mode, and for controlling said second and third switching means to connect said audio signal input and output terminals of said external terminal unit respectively to a transmitter and receiver of said external telephone through said Internet telephone call processing means; and input/output interfacing means for interfacing input/output data between said external terminal unit and said Internet telephone interfacing device.

2. The Internet telephone interfacing device as set forth in Claim 1 , wherein said Internet telephone call processing means includes: a subscriber line interface circuit for interfacing a subscriber line between said external terminal unit and said external telephone; a ringer for generating a ring tone to said external telephone when an Internet incoming call termination occurs; an office line call termination alarm generator for generating an alarm to said external telephone when said office line incoming call termination occurs while said Internet telephone call is established; a hook-off detector for detecting hook-off state of said external telephone; and a call waiting tone generator for generating a call waiting tone to said external telephone when said external telephone is at hook-off state.

3. The Internet telephone interfacing device as set forth in Claim 1 , wherein said office line telephone call processing means includes: an office line call termination detector for detecting the occurrence of said office line incoming call termination; an Internet call termination alarm generator for generating an alarm to said external telephone when an Internet incoming call termination occurs while an office line telephone call is established; and a hook-off detector for detecting hook-off state of said external telephone.

4. The Internet telephone interfacing device as set forth in Claim 1 , wherein each of said first to fourth switching means includes a relay element.

5. The Internet telephone interfacing device as set forth in Claim 1 , wherein said external terminal unit is a personal computer.

6. An Internet protocol server system for realizing an Internet telephone call using an Internet protocol, comprising: a plurality of personal computers assigned with Internet protocol numbers; an Internet service provider for connecting said personal computers to the

Internet; and an Internet protocol server system for storing said Internet protocol numbers of said personal computers in a database together with the identification numbers of said associated members, searching said Internet protocol number of a specific personal computer from said database upon request from a different personal computer and providing the searched Internet protocol number to said different personal computer.

7. The Internet protocol server system as set forth in Claim 6, wherein said Internet protocol numbers of said personal computers are variable.

8. A method for setting up initial environments of an Internet telephone interfacing device, comprising the steps of: a) powering on an external terminal unit connected to said Internet telephone interfacing device; b) accessing an Internet service provider server through said external terminal unit and acquiring a unique Internet protocol number therefrom; and c) setting up the initial environments of said Internet telephone interfacing device according to an application program installed in said external terminal unit.

9. The method as set forth in Claim 8, wherein said step c) includes the steps of: c-1) setting an initial transmission path of an external telephone; c-2) setting a transmission path change code for changing said initial transmission path of said external telephone set at said step c-1); and c-3) setting a connection priority of the Internet telephone companies for realizing an Internet telephone call over said external telephone.

10. A method for realizing an Internet telephone call over an Internet telephone interfacing device using an external telephone, comprising the steps of: a) checking the initial transmission path of said external telephone; b) establishing a speech path between said external telephone and a party over the Internet if said initial transmission path of said external telephone is set to an Internet telephone mode; c) transferring audio signal from an external terminal unit connected to said external telephone to a receiver of said external telephone; and d) transferring audio signal from said external telephone to an audio input terminal of said external terminal unit.

1 1. The method as set forth in Claim 10, further comprises the step of e) establishing a speech path between said external telephone and said party over an office line connected to a public telephone network if said initial transmission path of said external telephone is set to an office line telephone mode.

12. The method as set forth in Claim 10, wherein said step b) includes the steps of: b-1) receiving a combination of dial key signals from said external telephone; b-2), if the received dial key signal combination represents a telephone number of said party, accessing an Internet telephone company server and establishing an Internet telephone call between said external telephone and said party; and b-3), if the received dial key signal combination represents an Internet protocol number of said party, connecting directly to said party over the Internet via an Internet service provider and establishing an Internet telephone call between said external telephone and said party.

13. The method as set forth in Claim 12, wherein said step b) further includes the steps of: b-4), if the received dial key signal combination represents a code for changing said initial transmission path of said external telephone, changing and setting said initial transmission path of said external telephone to said Internet telephone mode if it is currently set to said office line telephone mode; and b-5) changing and setting said initial transmission path of said external telephone to said office line telephone mode if it is currently set to said Internet telephone mode.