JP2006166468A - Speech terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To preliminarily prevent any prank call or wrong call in the terminal of the Internet telephone. <P>SOLUTION: Each terminal of a computer network is connected through a server, and data including voice data are transferred through the computer network. Calling side information transmitted from the server is received, and an operation corresponding to the transmitted calling side information is performed. Whether or not the calling side terminal is a preliminarily specified calling side is determined, and connection/non-connection is operated according to the result. At the time of receiving a call, it is possible to acquire information of the calling side, and to preliminarily prevent any prank call or wrong call. Also, the information at the calling side is stored so that it is possible for a user to know information showing the origin of call when the user is absent. Furthermore, it is possible for the user to determine the call from the Internet or the call from a normal public telephone line at the time of receiving a call, and to perform processing corresponding to this. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a terminal device of a telephone system suitable for use in an Internet telephone that transmits and receives audio data using the Internet, which is a global computer network.

  The Internet is a computer network that connects computer networks existing in companies, universities, and the like through wide-area lines, and is spread all over the world. Various services using the Internet, such as an e-mail service, a file transfer service, and an information search service, have been actively performed.

  FIG. 12 shows an overview of the Internet. In FIG. 12, NET101, NET102, NET103,... Are computer networks. Each of the computer networks NET101, NET102, NET103,... Has a plurality of terminals T, T, T,. The terminals T, T, T,... Of each computer network NET101, NET102, NET103,... Are connected by a LAN (Local Area Network). As a form of LAN, Ethernet, token ring, or the like is used.

  The computer networks NET101, NET102, NET103,... Are connected to each other via routers R101, R102, R103,. The routers R101, R102, R103,... Perform routing processing for delivering data on the computer network to other computer networks depending on the destination.

  As described above, the computer networks NET101, NET102, NET103,... Are connected via the routers R101, R102, R103,. Such a computer network is called the Internet. The Internet makes it possible to transfer data between computer networks NET1, NET2, NET3,.

In the Internet, IP (Internet Protocol) is used as a network layer protocol.
) Is used. In IP, an IP address is assigned to each terminal, and a destination to which data is transferred is identified by the IP address. The IP address is made up of four numbers that can be represented by 8 bits in binary, and is expressed as, for example, “43.3.25.246”.

  As the Internet spreads, IP address shortages are feared. Therefore, when there are a large number of terminals registered on a network and a small number of terminals that are actually connected, in order to save IP addresses, a server for assigning IP addresses on the network is provided. An empty IP address may be assigned only when the terminal is connected. In this way, it is not necessary to prepare IP addresses for the number of terminals, and a limited number of IP addresses can be used effectively.

  In the Internet, TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are used as transport layer protocols. TCP performs communication after making a so-called connection-type communication connection, and has a function of performing packet order control, retransmission, flow control, and congestion control. UDP is a connectionless protocol and is used in place of TCP when real-time performance is required. For example, in digital voice communication or the like, even if a part of a packet is dropped, the retransmission is not requested and the voice is transmitted without interruption. In the case of such voice communication, UDP is used.

  In this way, the Internet basically uses the TCP / IP protocol. That is, an IP address is assigned to a terminal of a computer network, and this IP address is used for terminal identification. Then, the packet is transferred by TCP or UDP.

  However, personal computers are not necessarily connected by a LAN and may not have an IP address. Therefore, when an individual participates in the Internet, a company called an Internet service provider is used. When an Internet service provider is used, a personal computer is connected to a computer network using a telephone line, for example, PPP (Point to Point Protocol) or SLIP (Serial Line IP), and can participate in the Internet.

  That is, FIG. 13 is an example of an Internet service provider. The Internet service provider computer network NET 151 includes a server S 151 and a router R 151. The server S151 is connected to the public telephone line network TEL151 via modems M151, M152, M153,.

  Terminals T151, T152, T153,... Are terminals of individuals who participate in the Internet individually. Terminals T151, T152, T153,... Are connected to a public telephone line network TEL151 via a modem (not shown). As personal terminals T151, T152, T153,..., Personal computers having serial ports can be used.

  When participating in the Internet using an Internet service provider, a contract is usually made in advance between the user and the company of the Internet service provider. When a contract is made between the user and the Internet service provider, an account name and password are sent to the user.

  When participating in the Internet from personal terminals T151, T152, T153,..., The user dials the Internet service provider and calls the computer network NET151 of the Internet service provider. When the server S151 receives the call, the server S151 requests input of an account name and a password, and authenticates whether a contract is concluded with the Internet service provider. When it is verified that the entered account name and password are correct and a contract is made with the Internet service provider, the server S151 searches for a free IP address, and if there is a free IP address. , This IP address is assigned to terminals T151, T152, T153,... As temporary IP addresses. As a result, temporary IP addresses are assigned to the terminals T151, T152, T153,...

  In the above example, a PPP connection is made using a telephone line, but an ISDN (Integrated Service Digital Network) may be used. The ISDN 64 is composed of 3 channels in total, two B channels of 64 kbps and one D channel of 16 kbps in one line. When ISDN is used, it can be used as a 64-kbps line by flowing an IP packet on the B channel.

  Development of an Internet telephone that uses the Internet to make a call with the other party is underway. Since the Internet is basically free of charge, Internet telephones that use the Internet to make calls can be made only with charges generated by contracts with Internet service providers, telephone charges to Internet service providers, and ISDN usage charges. It is possible to make long distance calls and international calls at a very low price.

  By the way, a conventional telephone may receive a call from a useless person such as a prank call or a wrong call. In the case of a telephone using the Internet, a mischievous telephone call or a wrong telephone call may occur. For this reason, it is necessary to deal with mischievous calls and wrong calls. Also, if you receive a phone call when you are away, you want to keep a list of who is calling and what are the requirements. Furthermore, there is a case where a telephone from an ordinary public telephone line comes to a telephone using the Internet. As described above, when a call is received from a normal public telephone line, it is desired to be able to function as a normal telephone.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a terminal device of a call system that can obtain information on the calling side when a call is received through the Internet, and can prevent mischief calls and wrong calls. .

  Another object of the present invention is to provide a terminal device of a telephone system that can store information on the other side of an Internet telephone that has been in the absence.

  Still another object of the present invention is to provide a terminal device for a call system that can determine whether the call is from the Internet or a normal public telephone line when a call is received, and can perform processing corresponding to the call. There is.

  The present invention is a terminal device of a telephone system in which a computer network is formed, each terminal of the computer network is connected through a server, and data including at least voice data is transferred by the computer network. Thus, the terminal device of the call system is characterized in that it receives the information on the calling side sent from the server and performs an operation according to the information on the calling side sent.

  In the present invention, the operation according to the information on the calling side sent is to determine whether or not the calling side terminal is a previously specified calling side and to connect / disconnect accordingly. is there.

  In the present invention, the operation according to the information on the calling side sent is to set the ringing tone according to the terminal on the calling side.

  In the present invention, the operation according to the information on the calling side sent is to display the information on the calling side.

  In the present invention, the operation according to the information on the calling side sent is to record the information on the calling side.

  The present invention is a terminal device of a telephone system in which a computer network is formed, each terminal of the computer network is connected through a server, and data including at least voice data is transferred by the computer network. A public telephone connection means for making a call using the public telephone line, and a means for judging whether the call is from the computer network or only from the public telephone line, and only the call from the computer network is from the public telephone line. This is a terminal device of a telephone system that performs an operation only in response to a call.

  According to the present invention, when a call is received, information on the calling side can be obtained, and mischief calls, wrong calls, etc. can be prevented in advance. In addition, by storing the information on the calling side, it is possible to know the information on where the call is from when there is no call. Further, when a call is received, it is determined whether the call is from the Internet or from a normal public telephone line, and processing corresponding to the call can be performed.

  The present invention is applied to an Internet telephone that communicates voice data using the Internet, and is particularly suitable when the Internet telephone is used in a PPP connection using a public telephone line network.

  FIG. 1 shows an example of an Internet telephone system to which the present invention can be applied. In FIG. 1, a computer network NET1 is, for example, a computer network of an Internet service provider. The computer network NET1 has a server S1 and a router R1.

  The server S1 is connected to the public telephone network TEL1 via modems M1, M2, M3,. Currently, data can be transmitted at 28.8 Kbps by a high-speed modem using the public telephone line network TEL1.

  The computer network NET1 is connected to another computer network constituting the Internet via the router R1. The router R1 performs a routing process for delivering data on the computer network to another computer network depending on the destination.

  The terminals T1, T2, T3,... Are, for example, terminals of individuals who participate in the Internet individually. As the terminals T1, T2, T3,..., A personal computer installed with an Internet telephone program is used, and a dedicated Internet telephone can be used. As will be described later, the dedicated Internet telephone is a terminal dedicated to the Internet telephone that can easily make a call using the Internet.

  The server S1 has a database DB1. As shown in FIG. 2, the database DB1 includes “terminal name”, “terminal Japanese name”, “notation name on the Internet”, “connection type”, “phone number for PPP”, “user name”, Etc. are recorded. The database DB1 is constructed, for example, using information obtained from contract contents when a contract is made between an Internet service provider and a user. In the database DB1, when the connection format is PPP, information on the telephone number for PPP of the person who has contracted with the Internet service provider through PPP connection is included.

  In this example, the server S1 and the terminals T1, T2, T3,... Are PPP-connected via a public telephone line network, but may be connected using a digital network such as ISDN.

  Next, call control in a call system to which the present invention can be applied will be described. For example, in FIG. 1, it is assumed that the terminal T1 calls the terminal T2 to make a call. In the Internet, the other party is specified using an IP address. In this case, since the other party's terminal T2 is a terminal connected by PPP, it is not always connected to the computer network NET1. For this reason, the other party's terminal T2 cannot be called using the IP address. Therefore, the database DB1 is used.

  That is, FIG. 3 is a flowchart showing the procedure at that time. First, the calling terminal T1 dials the Internet service provider NET1, and the Internet service provider NET1 is called. When the server S1 of the internet service provider NET1 receives the call, it requests the terminal T1 to input an account name and a password, and makes an authentication request as to whether or not a contract is concluded with the internet service provider. The user of the calling terminal T1 inputs the account name and password in response to this authentication request. If it is verified that the entered account name and password are correct and a contract is concluded with the Internet service provider, the server S1 assigns a temporary IP address to the terminal T1. Thereby, PPP connection with the terminal T1 is started (step ST1).

  Next, the terminal T1 designates the address (for example, the terminal T2) of the other party who wants to talk (step ST2).

  When the address of the other party is designated, the server S1 searches for information on the terminal T2 using the database DB1. From the information in the database DB1, the telephone number for PPP connection of the terminal T2 is known (step ST3).

  The server S1 determines an IP address for designating the partner terminal T2 in the server, prepares for PPP connection, and notifies the calling terminal T1 of the IP address of the partner terminal (step ST4).

  Then, the server S1 dials the telephone number of the terminal T2 retrieved from the database DB1, and calls the terminal T2. When the connection of the telephone line with the counterpart terminal T2 is confirmed, the server S1 performs authentication and assigns an IP address to the counterpart terminal (step ST5).

  Thereby, PPP connection is started (step ST6). Then, voice data is transmitted and received between the terminal T1 and the terminal T2, and a call is performed (step ST7). Note that the audio data is transmitted after being compressed. When transmitting and receiving audio data, UDP is used as a transport layer protocol.

  When the call is finished, all connections such as PPP connection and telephone line connection between the terminal T1 and the server S1, and PPP connection and telephone line connection between the terminal T2 and the server S1 are terminated (step ST8).

  In the above example, the IP address of the terminal T2 is determined before completing the call of the terminal T2, but the IP address of the terminal T2 is determined after the call of the terminal T2 is completed. May be. At this time, the determined IP address may be communicated to the calling terminal T1 as necessary. When the server determines the IP address of the partner terminal, the communication side with the partner terminal can be prepared in advance by contacting the calling party with the IP address. Can be smoothly started.

  As described above, when the database DB1 having the information of the telephone number for PPP connection is provided and the other party of the call is a PPP connected terminal (for example, T2), the other party is based on the telephone number information of the database DB1. Is called. Then, the partner terminal T2 is connected to the server S1 by PPP. As a result, even when the other party of the call is a PPP-connected terminal, the other party can be called to make a call.

  In the above-described example, a case where a call is made between terminals in the same computer network has been described. However, a call can also be made with a terminal in another computer network. FIG. 4 shows an example in which a telephone call is made between terminals between different computer networks.

  In FIG. 4, a computer network NET11 is, for example, a computer network of an Internet service provider. The computer network NET11 has a server S11 and a router R11. The server S11 is connected to the public telephone line network TEL11 via modems M11, M12, M13,. The server S11 has a database DB11. The database DB11 stores information including telephone numbers of terminals connected to the computer network NET11 by PPP. The computer network NET11 is connected to another computer network constituting the Internet via the router R11. The router R11 performs a routing process for delivering data on the network to the network according to the destination. Terminals T11, T12, T13,... Are, for example, terminals of individuals who participate in the Internet.

  The computer network NET21 is, for example, a computer network of another Internet service provider. The computer network NET21 has a server S21 and a router R21. The server S21 is connected to the public telephone line network TEL21 via modems M21, M22, M23,. The server S21 has a database DB21. The database DB21 stores information including the telephone numbers of terminals connected to the computer network NET21 by PPP. The computer network NET21 is connected to another computer network constituting the Internet via the router R21. The router R21 performs routing processing for delivering data on the network to the network according to the destination. The terminals T21, T22, T23,... Are, for example, terminals of individuals who participate in the Internet individually.

  For example, assume that a call is made from the terminal T11 of the computer network NET11 to the terminal T21 of the computer network NET21. In this case, processing as shown in FIG. 5 is performed.

  First, the terminal T11 on the calling side is dialed to the network NET11 of the Internet service provider, and the server S11 of the computer network NET11 is called.

  When the server S11 receives the call, the server S11 requests input of an account name and a password, and makes an authentication request as to whether or not a contract is concluded with the Internet service provider.

  The user of the calling terminal T11 inputs the account name and password in response to this authentication request. When it is verified that the entered account name and password are correct and a contract is concluded with the Internet service provider, the server S11 assigns a temporary IP address to the terminal T11. Thereby, the PPP connection of the terminal T11 is started.

  Next, a call request is sent from the terminal T11 to the server S11, and a call response is returned from the server S11 to the terminal T11. If a call response is returned, the address of the other party (for example, terminal T21) to be called is designated.

  When the destination address is specified, the server S11 including the calling terminal sends a call request to the terminal T21 to the server S21 of the computer network (for example, the computer network NET21) including the other party. When the server S21 receives a call request to the terminal T21, the server S21 returns a call response to the server S11. When the server S11 of the network NET11 including the calling side terminal receives a call response, the server S11 sends the address of the called party and also sends the calling side information.

  The server S21 of the computer network NET21 including the other party searches for information on the terminal T21 using the database DB21. From the information in the database DB21, the telephone number for PPP connection of the terminal T21 is known. The server S21 of the computer network NET21 dials the telephone number of the terminal T21 retrieved from the database DB21 and calls the terminal T21.

  When receiving the call from the server S21, the partner terminal T21 returns a call response to the server S21. When the server S21 receives the call response, the server S21 makes a PPP connection request. When the server T21 receives the PPP connection request, the server T21 informs that the PPP connection is established.

  Then, the server S21 requests input of an account name and password and performs authentication. The user at the other end inputs the account name and password according to this authentication. If it is confirmed that the entered account name and password are correct and a contract is made with the Internet service provider, an IP address is assigned to the terminal T21. Thereby, the PPP connection of the terminal T21 is started.

  When the PPP connection is started, a call request is sent from the server S21 to the terminal T21, and a call response is returned from the terminal T21 to the server S21. Then, a call connection completion is sent from the server S21 of the computer network NET21 to the server S11 of the computer network NET11, and a call completion is sent from the server S11 to the terminal T11. Then, voice data is transmitted and received between the terminal T11 and the terminal T21, and a call is performed.

  When the call is completed and, for example, a disconnection request is issued from the calling terminal T11, the disconnection request is sent to the partner terminal T21. Upon receiving the disconnection request, the terminal T21 returns a disconnection response to the terminal T11 and disconnects all connections.

  In the Internet telephone system, a dedicated Internet telephone can be used as a terminal.

  FIG. 6 shows an example of an Internet telephone. In FIG. 6, reference numeral 1 denotes a telephone body. A display operation unit 2 is provided on the upper surface of the telephone body 1. As shown in FIG. 7, the display operation unit 2 has a structure in which a touch panel 4 is laminated on a display panel 3. Icons indicating numeric keys, operation keys, and the like are displayed on the display operation unit 2, and necessary input can be performed by pressing the touch panel 4 on the icons. In addition to icons indicating keys and the like, the display operation unit 2 displays help for operation guidance and a setting state. Further, various information is displayed on the display operation unit 2. A handset 5 is connected to the telephone body 1. The telephone body 1 is connected to a public telephone line.

  FIG. 8 shows the internal configuration of the Internet telephone. In FIG. 8, 11 is a CPU. A ROM 12, an EPROM 13, and a RAM 14 are connected to the CPU 11. Further, an input is given to the CPU 11 from the touch panel 4, and an output of the CPU 11 is displayed on the display panel 3.

  The CPU 11 performs dial connection processing, IP data transfer processing, and audio signal compression / decompression processing. That is, when the address of the other party is input from the touch panel 4, the CPU 11 controls the NCU 14 to dial the telephone number of the internet service provider's computer network and perform telephone connection processing. When the telephone connection is completed, connection processing by PPP is performed. In addition, there is a case where a PPP connection is requested by receiving an incoming call from a computer network of an Internet service provider. Also in this case, the CPU 11 performs a telephone connection process, and when the telephone connection is completed, performs a connection process by PPP. During a call, the audio signal to be transmitted / received is compressed / decompressed and communication processing by IP is performed.

  The audio signal from the microphone of the handset 5 is digitized by the A / D and D / A converter 18. This digital audio signal is sent to the CPU 11 and subjected to compression processing. The compressed audio signal is supplied to an NCU (Node Control Unit) 16 via a modem 15.

  The compressed audio signal sent via the telephone line is sent to the CPU 11 via the NCU 16 and the modem 15. The CPU 11 performs audio signal expansion processing. The expanded digital audio signal is sent to the A / D and D / A converter 18 and converted into an analog signal. Then, it is supplied to the speaker of the handset 5.

  This Internet telephone can be used as a normal telephone. In the case of functioning as a normal telephone, the handset 5 and the NCU 14 are connected via the speech net 17 and a call is made with an analog voice signal via the telephone line.

  Usually, in order to use an Internet telephone by PPP connection, a personal computer is prepared, a microphone and a speaker are connected to the personal computer, and software for connecting to the Internet must be incorporated. However, it is not easy for a user who is not familiar with a computer to prepare a personal computer and connect it to the Internet. In addition, using the Internet telephone by making a PPP connection with a computer results in poor operability and high cost.

  The above-described Internet telephone does not need to incorporate software for connecting to the Internet, and can be easily connected to the Internet to perform voice communication. Moreover, the handset 5 is provided similarly to a normal telephone, and it can be operated similarly to a normal telephone. Therefore, even a user unfamiliar with a computer can easily use the Internet telephone. In particular, in the above-described Internet telephone, the display operation unit 2 having a structure in which the touch panel 4 is laminated on the display panel 3 is provided, so that the operability is good.

  By the way, even in the case of a telephone using the Internet, a mischievous telephone call or a wrong telephone call may occur. For this reason, it is necessary to deal with mischievous calls and wrong calls. In addition, there is a case where a telephone from an ordinary telephone line is received by a telephone using the Internet. Thus, it is desirable to be able to function as a normal telephone when there is a call from a normal telephone line.

  Therefore, in the Internet telephone to which the present invention is applied, when a call from the other party is received, processing as shown in FIG. 9 is performed.

  In FIG. 9, it is determined whether or not a call has been received (step ST11). When a call is received, a ringing tone is emitted (step ST12). Then, it is determined whether there is only a modem call for making an Internet phone call or a call for making a call on a normal telephone line (step ST13). Whether it is a call from a modem or a call from a general telephone can be determined by receiving, for example, a European calling tone from a server.

  If it is determined in step ST13 that the call is from a normal telephone, it is determined whether or not a call is started within a predetermined time (steps ST14 and ST15). If a telephone call is picked up within a predetermined time and a call is started, then the call is continued (step ST16). If the call is not started within the predetermined time, an absence message is transmitted (step ST17), and it is determined whether there is a message from the other party (step ST18). If there is no message, it disconnects as it is (step ST19), and if there is a message, it stores the message (step ST20) and disconnects (step ST19).

  If it is determined in step ST13 that the call is from a modem, connection processing by PPP as shown in FIG. 3 is performed (step ST21). It is determined whether or not the PPP connection process is completed (step ST22). When the connection process is completed, information on the calling side is acquired (step ST23).

  The calling side information is compared with the call rejection information registered in advance, and it is checked whether or not the calling side terminal is a call rejection terminal (step ST24). That is, as shown in FIG. 10, a terminal that wants to refuse a call or a terminal that permits a call only to that terminal is registered in the call rejection or call permission list in advance. Using this information, it is checked whether the calling terminal is a call rejection terminal.

  In the case of a call rejection terminal, PPP disconnection processing is performed (step ST25), and then the line is disconnected (step ST19).

  In the case of a call from a terminal that is permitted to call in step ST24, it is determined whether or not a call has been started by picking up the handset within a predetermined time (steps ST26 and ST27). If a call is started within a predetermined time, then the call is continued (step ST28).

  If the call is not started within the predetermined time, an absence message is transmitted (step ST29), and it is determined whether there is a message or an e-mail from the other party (step ST30). If there is a message or e-mail, the message or e-mail is saved (step ST31), and the caller information is saved (step ST32). If there is no message or e-mail in step ST30, the process goes to step ST32 and the calling party information is stored.

  Then, the process goes to step ST24, and after the PPP cutting process is performed, the cutting is performed (step ST19).

  As described above, in the Internet telephone to which the present invention is applied, when a call from the modem is received for the Internet telephone, information on the calling side is stored. For example, as shown in FIG. 11, a list of incoming call information is shown from this information. Using this incoming call information, it is possible to know from which party the call is received. Note that the information on the calling side to be stored may include the name of the caller, the country of the caller, the date and time of call, the date and time of call arrival, and the like. If there is a message or e-mail, the user can listen to the message or view the e-mail. Moreover, you may make it set a signal sound and a melody corresponding to the other party. Further, different combinations of signal sounds, melodies, voice messages, e-mails, and the like may be set in advance for each caller depending on the priority.

It is a block diagram used for description of an example of the internet telephone system which can apply this invention. It is a basic diagram used for description of an example of the internet telephone system which can apply this invention. It is a flowchart used for description of an example of the internet telephone system which can apply this invention. It is a block diagram used for description of the other example of the internet telephone system to which this invention was applied. It is a flowchart used for description of the other example of the internet telephone system which can apply this invention. It is a perspective view of an example of the telephone of the internet telephone system to which this invention was applied. It is sectional drawing used for description of an example of the telephone of the internet telephone system which can apply this invention. It is a block diagram of an example of the telephone of the internet telephone system to which this invention was applied. It is a flowchart used for description of an example of the telephone of the internet telephone system to which this invention was applied. It is a basic diagram used for description of an example of the telephone of the internet telephone system to which this invention was applied. It is a basic diagram used for description of an example of the telephone of the internet telephone system to which this invention was applied. It is a block diagram used for description of the Internet. It is a block diagram used for description of PPP connection.

Explanation of symbols

1 Telephone body 11 CPU
16 NCU

Claims (6)

A terminal device of a telephone system that forms a computer network, performs connection between each terminal of the computer network via a server, and transfers data including at least voice data through the computer network,
A terminal device of a call system, characterized in that it receives caller information sent from a server and performs an operation according to the caller information sent.   The operation according to the information on the calling side sent is to determine whether or not the calling side terminal is a previously specified calling side, and to connect / disconnect accordingly. Item 4. The terminal device of the telephone system according to Item 1.   2. The terminal device for a call system according to claim 1, wherein the operation according to the transmitted information on the calling side sets a ringing tone according to the terminal on the calling side.   The terminal device of the call system according to claim 1, wherein the operation according to the sent caller side information displays the caller side information.   2. The terminal device for a call system according to claim 1, wherein the operation according to the transmitted information on the calling side records the information on the calling side. A terminal device of a telephone system that forms a computer network, performs connection between each terminal of the computer network via a server, and transfers data including at least voice data through the computer network,
A public telephone connection means for making a call using a public telephone line;
Means for determining whether the call is from the computer network or only from the public telephone line;
A terminal device of a telephone system that performs an operation corresponding to only a call from the computer network or a call from the public telephone line.

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