KR20010079469A - A method and architecture of PSTN call on a Internet telephony gateway for SOHO - Google Patents

Abstract

PURPOSE: A structure and method for using a generic PSTN telephone in a SOHO Internet phone gateway is provided to offer the calling and receiving functions of both an Internet phone and a PSTN telephone, regardless of a connected state, by confirming a connection state according to suitable procedures. CONSTITUTION: Tip/ring terminals(21) are connected with a subscriber line of a PSTN telephone office. A terminal(22) is to connect a generic telephone. An AC input terminal(23) supplies system power. A relay(24) is provided for connection transfer when a user attempts an Internet call and a PSTN through the generic telephone. A DC power supplier supplies DC power. A loop detector(26) monitors the loop of the call current of a PSTN trunk. A ring detector(27) detects a ring signal. A SLIC(Subscriber Line Interface Circuit)(28) supplies call current and ring signals for Internet calls. A relay driver(29) drives a signal transfer relay.

Description

A method and architecture of PSTN call on a Internet telephony gateway for SOHO}

With the spread of the Internet and the development of voice telephone transmission technology using the Internet, technologies and products for providing Internet telephony using conventional telephones have been recently developed, but VOIP (Voice) of general telephone adapter function suitable for home or small office over IP) It adds PSTN and Internet phone selection function by adding exchange function, and it has costly disadvantages. In consideration of cost, products that have a structure that cannot call PSTN at all It is coming true.

Therefore, in the present invention, a circuit that simply selects without inserting a complicated switching function is configured so that the basic connection state is connected to the PSTN trunk line, connected to the Internet telephone path side, or the ring call incoming signal and preference of the PSTN trunk line without distinction. Provides a control procedure and method that monitors the loop status of the system and checks the two statuses in the proper order while providing the functions of making and receiving Internet calls and making and receiving PSTN calls.

1 is a block diagram of the present invention

2 is a block diagram of a general SOHO Internet telephone gateway system to which the present invention is applied

Fig. 3 Flowchart of method for selecting Internet and PSTN telephone path (Method 1)

Fig. 4 Flowchart of method for selecting Internet and PSTN telephone route (Method 2)

As shown in Fig. 2, the present invention provides a tip / ring terminal (21) connected to a subscriber line of a PSTN telephone station, a terminal (22) for connecting a general telephone, and an AC input terminal for supplying power to the system (23). , Relay 24 for switching the connection when attempting Internet phone and PSTN phone in normal telephone, DC power supply 25 inside the system, loop detector circuit 26 for loop current of PSTN telephone trunk line, trunk line Ring Detector (27) for ring signal detection, which is a signal for calling the telephone in the phone, SLIC (28) which functions as a call current or ring signal supply of the telephone for making an Internet phone call, Relay Driver for driving a signal switching relay (29) and the like.

With reference to the accompanying drawings will be described embodiments of the present invention;

1 is a block diagram of a general small Internet telephone gateway system to which the present invention is applied. In the drawing, reference numeral 11 denotes an Internet telephony protocol such as H.323 including a system control function and kernel TCP / IP for performing an Internet telephony function. 12 is a CODEC for decompressing and reconstructing a voice signal for Internet telephony, and (13) SLIC which is a subscriber line interface for supplying call current and ring signal supply hook on / off of a general telephone. (Subscriver Line Interface Circuit), (14) is a function of the present invention Internet telephone and PSTN telephone switching function, (18) is a trunk line terminal connected to the telephone company, (19) a tip / ring terminal for connecting a general telephone, 15 is an Ethernet MAC (Medium Access Control) which is a physical interface of a network for providing an Internet telephony function, and (16) an Ethernet physical layer function (20) is a LAN or high-speed Internet. It consists of xDSL modem or cable modem to provide connection.

Referring to the operation of Fig. 2, the general telephone connected to the terminal (22) makes an internet call through the route of the SLIC of (28) or the PSTN trunk line connected to the terminal (21) to select and communicate with the relay ( Can be selected using 24). In this case, (21) LOOP Detector (26) connected to the telephone trunk line is connected in series with the subscriber card of the telephone company and (24) when the contact of the relay is connected to the telephone connected to (22) to detect the hook off state and output signal ( 26-1) to the system control unit 11. In addition, the ring detector 27 connected in parallel to the telephone line 21 detects the ring call signal 27-1 when receiving a ring signal from the telephone station regardless of which position the contact point of the relay 24 is located. Notified to the system control unit. The relay driver 29 is a circuit for driving in accordance with a control signal 29-1 for selecting the path of the SLIC 28 side so that the system controller 11 uses the PSTN trunk line side or the Internet telephone in the telephone.

As shown in Figs. 3 and 4, the system control unit 11 uses the components shown in Fig. 2 to receive or transmit Internet telephones and to and receive PSTN telephones from a general telephone connected to the terminal 22. A flowchart of this possible method is illustrated. The difference is that, in FIG. 3, a process flow diagram in which the contact point of the relay 24 is basically connected in the direction of the PSTN trunk line terminal 21 is shown. In FIG. 4, the direction of the contact point is directed to the SLIC 28 side for using an Internet telephone. This is a flow chart of the basic connected state.

In FIG. 3, the telephone call processing unit 31 connects a general telephone with the relay's position initially connected to the trunk line 21 to serve. Monitors the state of Loop detect output signal 26-1 and Ring Detect output signal 27-1. If Loop Detect is done first as in (33), it recognizes that the handset is hooked-off in a general telephone (37). If you want to make an internet call by first receiving one DTMF digit and interpreting (39) the relay's location to the SLIC (28) that can make an internet call, enter the call connection procedure by recognizing a continuous DTMF (40). ). If the call is terminated after successive phone calls (42), the relay switches to the PSTN trunk line as the initial condition. (32)

At this time, in the situation where the user wants to make a call to the PSTN, at 39, he / she recognizes that he / she wants to make a PSTN call and immediately switches the relay to the PSTN trunk line, receives a dial tone from the telephone station, transmits DTMF, and makes a call with the desired number. During the call process, the Loop Detect state is continuously checked (36) to be hook-on to detect that the loop is not formed and return to the initial state. At this time, since the relay is located on the PSTN trunk line side, a separate switching action is unnecessary.

When receiving a call from an external PSTN trunk line, if a ring signal is detected 34 in a state where a loop state is not formed at 33, it is determined that the PSTN is called. However, the system continuously monitors only this loop state to confirm that the call is terminated and does not need to perform any other processing. However, if there is a call through the Internet phone while the call is still active, the call may be rejected as a call or may be notified to the busy user through other means.

If a call is received by a procedure of an Internet call (43) and (44), first check whether the phone is busy with the PSTN call (45). If the call is busy, notify the other party that it is busy and release the call. Just enter If not in a call, the relay first switches to the direction of the Internet phone (46) and sends a ring signal through the SLIC to ring the phone. (47) The system controller detects the SLIC state to detect that a loop is formed. If it stops the ring signal transmission and enters the call state. (41) Also, the call termination state detects and recognizes the state of the slic and returns to the initial state to wait.

The present invention is applied to a small matching device for providing a voice telephone service through an internet network using a general telephone, so that the PSTN telephone cannot be provided when a normal Internet telephone service cannot be provided due to a power failure or system failure. It is easy to configure a switching device of the complementary dimension so that the present invention provides a function of selectively using the PSTN phone and the Internet phone at any time, usually at a low cost. This may provide a means of adapting to use only PSTN telephones when it is difficult to monitor the quality of the internet traffic to ensure quality.

Claims (5)

1. A device for selecting a PSTN trunk line and an internet telephone route of a matching device that can use an internet telephone using a general telephone. Loop detection means 26 for recognizing the relationship between the means 24 for selecting the PSTN trunk line 21 and the Internet telephone route 28 and its driving circuit 29 using the general telephone 22, and the state of the PSTN trunk line. And the power detection means 25 or the like so that the telephone 22 is basically connected to the PSTN trunk line 21 when the power is not applied according to the relationship between the ring signal detection means 27 which is a call signal and a call signal, and the state of the external AC power. Having structure and function: 2. The method of paragraph 1, When the default connection state of the route selection means 24 is set to PSTN 21 to receive or make an Internet or PSTN call, the comparison procedure of the loop state and ring call signal of the PSTN line and the switching procedure of the route selection means And method; 3. The method of clause 1, When the default connection state of the route selection means 24 is placed on the Internet route side 28 to receive or make an Internet or PSTN call, the comparison processing order of the loop state and ring call signal of the PSTN line and the route selection means Transition procedures and methods; 4. In paragraphs 2 and 3, A procedure and method for checking a connection state of a telephone with respect to a call connection request in the process of processing an Internet telephone call connection message of the system, and a call connection procedure and method; 5. In paragraphs 2 and 3, Procedure and method for recognizing a single DTMF for the selection of Internet phone and PSTN phone when making a call from a general telephone;