KR20040051926A - key phone system for enable session initiation protocol and method for call setup - Google Patents

Abstract

PURPOSE: A key phone system supporting an SIP(Session Initiation Protocol) method and a call setting method thereof are provided to perform a switching system function and a DISA(Direct Inward System Access) function while performing call connection. CONSTITUTION: An SIP terminal(11) performs a call setup for call communication by using a general SIP method. An SIP key phone terminal(10) performs a call setup for call connection by using the general SIP method and performs a function of using a service provided by a key phone system(20). A DTMF(Dual Tone Multi Frequency) interface unit(22) detects a DTMF signal received from the SIP key phone terminal(10) and supports a dedicated protocol used between the key phone system(20) and the key phone terminal when call connection is requested in a dedicated communication mode. An SIP interface unit(21) receives an 'INVITE' message signal and a 'BYE' message signal when call connection is requested by an extension terminal. A message converter(23) converts a received SIP message into a dedicated communication signal. A controller(24) analyzes the received signal and detects a phone number of a terminal desired to be connected.

Description

Key phone system for enable session initiation protocol and method for call setup}

The present invention relates to a key phone system and a call setup method supporting a connection setup protocol method, and more particularly, the call connection of the terminal interworking with the key phone system is based on the connection setup protocol method and the extension exchange service and the DSA which is a function of a general key phone system. The present invention relates to a key phone system and a call setup method that support a connection setup protocol scheme that provides a (DISA) function.

A direct inward system access (DISA) function is a function that allows a user to directly call an extension or select another trunk line by dialing a trunk line of an exchange system from the outside.

The Session Initiation Protocol is a simple text based application layer control protocol for setting up and controlling a session between terminals or users. Allows you to create, modify, and terminate sessions. These sessions include teleconferences, phone calls, meetings, and instant messaging over the Internet.

This connection establishment protocol was developed by the Multi-Party Multimedia Session Control (MMUSIC) working group of the Internet Engineering Task Force (IETF). .

The general connection establishment protocol method performs call connection through a server between standard connection establishment protocol supporting terminals interworking with the Internet network.

1 is a flowchart illustrating the flow of a signal for establishing a call in a general connection establishment protocol method.

Referring to Fig. 1, a transmitting user agent (hereinafter referred to as 'UA') 40, a server Sever, and a receiving UA 42 are comprised.

The transmitting UA 40 performs a call connection request to the server 41 for a call connection for the voice call with the receiving UA 42 to perform a call setup.

The server 41 receives a call connection request from the transmitting UA 40, identifies a location to which the corresponding receiving UA 42 is connected, and performs a function of transmitting a call connection request signal to the receiving UA 42. do.

The receiving UA 42 receives a call connection request received from the server 41, transmits a return signal for the corresponding signal, and performs a call connection with the transmitting UA 40.

A UA is a function of receiving input from a user and establishing and terminating a media session with another UA.

A session is an active connection between a user and a computer, or two computers. That is, the connection between two terminals for making a call.

The transmission UA 40 transmits a message 'INVITE' to the server 41 (S 1).

The server 41 receiving the 'INVITE' message analyzes the received message and retransmits the 'INVITE' message to the corresponding receiving UA 42 (S 2).

Receiving the 'INVITE' message, the receiving UA 42 transmits the '180 Ringing' signal to the server 41, which means that it is receiving the 'INVITE' signal (S 3), and the server 41 sends the '180 Ringing' signal. Retransmit to the transmitting UA 40 (S4).

When the receiving UA 42 sends a '200OK' message to the server 41 that accepts the invitation for the session in the 'INVITE' message (S5), the server 41 transmits the received '200 OK' message. Retransmission is performed to 40 (S6).

The transmitting UA 40 transmits an 'ACK' message, which is a final acknowledgment message for the '200 OK' message, to the receiving UA 42 (S7).

Thereafter, a call is established between the transmitting UA 40 and the receiving UA 42 (S8).

After the call is connected and the call is connected, the receiving UA 42 transmits a 'BYE' message to the transmitting UA 40 to perform the termination of the call (S 9).

When the UA 40 receives the 'BYE' message from the receiving UA 42, the transmitting UA 40 transmits a '200 OK' message indicating that the message has been received and acknowledged to the receiving UA 42, and performs a call termination (S 10). .

Typically, a message used in the connection establishment protocol method is divided into a call control message and a call state message, and the format thereof is shown in Table 1 below.

Field name Contents kind Type of message IP Addr Internet Protocol (IP) address of the device Serialnum User's sequence number (call ID) User ID ID of the user Connect Phone Phone number of PSTN phone to connect NTP start time Network time required to call NTP stop time Network standard time at which the first packet is sent e mail Addr User's email address Version Version information of the terminal used RTP recv port Port number to which the device will send voice Option Designated by the user for special purposes

2 is a structural diagram illustrating a structure of an 'INVITE' message of a connection establishment protocol.

The 'INVITE' message consists of a start line 50, a general header 51, a request header 52, an entity header 53, a depletion line 54, and message information 55.

INVITE sip: kim@snu.ac.kr SIP / 2.0

The start line 50 having such a structure performs a function of notifying that the start of the 'INVITE' message.

Via: SIP / 2.0 / UDP lab.madang.ajou.ac.kr:5060

TO: S.J.Kim <sip: kim@snu.ac.kr>

From: S.W.Yoo <sip: yoo@madang.ac.kr>

Call-ID: 123456789@lab.madang.ac.kr

CSeq: 1 INVITE

The general header 51 having such a structure corresponds to a request message and a response message.

'Via' means the selected path, 'TO' specifies the responder of the request, 'From' specifies the initiator of the request, and 'Call-ID' is unique for all registrations of a particular call invitation or a specific client. 'CSeq' specifies the priority of the message.

Subject: About internet Telephony

The request header 52 having such a structure performs a function for explaining the purpose of the message.

Content-type: application / sdp

Content-Length: 157

The entity header 53 having such a structure performs a function that indicates the type and length of message information.

<CR LE>

The depletion line 54 having such a structure expresses the corresponding information in the capacity of the 'INVITE' message in the rules of the connection establishment protocol method, and performs a function of remaining capacity.

V = 0

o = Yoo 2890866526 2890844526 IN IP4 lab.madang.ajou.ac.kr

s = Phone Call

c = IN IP4 100.101.102.103

t = 0 0

m = audio 49170 RTP / AVP 0

a = rtpmap: 0 PCMU / 8000

The message information 55 having such a structure performs a function of informing information necessary for a call.

Such a call connection method using a general connection establishment protocol method has a problem in that it does not provide a general function of an exchange system, that is, an extension exchange function or a DC function.

In addition, in the case where the key phone is used in conjunction with the key phone system, when the key phone is far from the key phone system, a problem occurs that the function as the phone is paralyzed due to the attenuation of the exchanged signal.

Accordingly, the present invention has been devised to solve such a problem. In order to prevent paralysis of a telephone function due to attenuation of a signal, a call connection is performed in a connection establishment protocol method, and a function of an exchange system, that is, an extension exchange service. An object of the present invention is to provide a key phone system and a call setup method that support a connection setup protocol scheme that provides a Wadisa function.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flowchart for explaining the flow of a signal for establishing a call in a general connection establishment protocol method.

2 is a structural diagram illustrating a structure of an 'INVITE' message of a connection establishment protocol.

Fig. 3 is a block diagram for explaining a configuration of a circuit switching apparatus according to a first preferred embodiment of the present invention.

Fig. 4 is a block diagram illustrating the configuration of a connection setting protocol key phone terminal used in the present invention.

5 is a flowchart for explaining the flow of a method for performing an extension exchange in a connection establishment protocol scheme according to a first preferred embodiment of the present invention.

6 is a block diagram for explaining a configuration of a circuit switched network according to a second preferred embodiment of the present invention.

7 is a flowchart illustrating a flow of a method for providing extension service to an external subscriber according to a second preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: connection setting protocol (SIP) key phone terminal

10a: button input portion 10b: processor

10c: storage unit 10d: digital interface unit

11: connection setting protocol terminal

20: keyphone system

21: SIP interface unit 22: DTMF interface unit

23: message conversion unit 24: control unit

25: PSTN interface unit 26: Internet interface unit

30: public telephone network 31: incoming terminal

32: Internet network 33: VoIP terminal

40: Sending User Agent

41: Server 42: Receive User Agent

According to an aspect of the present invention, there is provided a keyphone system supporting a connection establishment protocol method, including: a SIP interface unit receiving a call connection request message signal of a connection establishment protocol method, and a call connection received through the SIP interface unit; A message converting unit for converting the request message signal into a signal that can be recognized by the key phone system, and receiving the converted signal from the message converting unit, grasping the receiving terminal telephone number among the received signals, and receiving the receiving terminal telephone number with the receiving terminal telephone number. And a control unit for converting the received signal into a call connection request message signal of a connection establishment protocol method and transmitting the same.

In addition, a call setup method that supports a connection establishment protocol method according to another aspect of the present invention, receiving a call connection request message signal of the connection establishment protocol method from any terminal, and the received call connection request message signal keyphone Converting the signal into a system recognizable signal; analyzing the converted signal; acquiring the called terminal number; reconverting the converted signal into a message signal of a connection setting protocol; Transmitting to a telephone number, transmitting a message signal, and performing call setup between each terminal.

In addition, the terminal supporting the connection establishment protocol method according to another aspect of the present invention, a button input unit for receiving the call connection request message information from any subscriber, and receives the message information from the button input unit, and receives the received message information A processor for temporarily storing and converting the received message information into a message signal of a connection setting protocol method, a storage unit for receiving and temporarily storing message information from the processor, and under control of the processor, And a digital signal converter for converting the message information into a message signal of a connection setting protocol method, and a digital interface for receiving the message signal converted from the signal converter and transmitting the message signal.

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

Fig. 3 is a block diagram illustrating the configuration of the circuit switching apparatus according to the first preferred embodiment of the present invention.

The following detailed description of the present invention takes a keyphone system as an example of a private exchange device as an example.

Referring to FIG. 3, the key phone system 20 includes a DTMF interface unit 22, a SIP interface unit 21, a message conversion unit 23, and a control unit 24.

In addition, there is a connection setting protocol key phone terminal 10 and a connection setting protocol terminal 11 installed in a general office in association with the key phone system 20.

The connection establishment protocol terminal 11 performs a function of making a call by performing call setup using a general connection establishment protocol method.

Connection Setting Protocol The keyphone terminal 10 uses a general connection setting protocol scheme for call setup for a call connection, and uses a service provided by the keyphone system 20 through a dedicated communication scheme with the keyphone system 20. To perform.

The DTMF interface unit 22 of the key phone system 20 does not use the connection setting protocol method from the connection setting protocol key phone terminal 10, and when there is a call connection request using a general communication method, that is, a call in a dedicated communication method. When there is a connection request, a function of detecting a dual tone multi frequency (DTMF) signal received from the connection establishment protocol key phone terminal 10 and a function of supporting a dedicated protocol used between the key phone system 20 and the key phone terminal. Do this.

The SIP interface 21 performs a function of receiving an 'INVITE' message signal and a 'BYE' message signal, which are received message signals, when a call connection request is received from the extension terminal using a connection establishment protocol method.

The message conversion unit 23 converts the message of the connection setting protocol method received through the SIP interface unit 21 into a signal that can be recognized by the key phone system 20, that is, a signal of a dedicated communication method.

The control unit 24 receives a signal received through the DTMF interface unit 22 and a signal received from the message conversion unit 23.

In addition, the controller 24 analyzes the received signal to determine the telephone number of the terminal to which the call is to be connected.

Fig. 4 is a block diagram illustrating the configuration of a connection setting protocol key phone terminal used in the present invention.

4, a button input unit 10a, a storage unit 10c, a processor 10b, a digital interface unit 10d, and a signal converter 10e are provided.

The button input unit 10a performs a function of allowing an extension subscriber to input button information, that is, button information and function button information corresponding to an incoming call number.

The storage unit 10c temporarily stores the information received through the button input unit 10a and stores other useful information when the extension subscriber requests a call connection in the connection establishment protocol method.

The processor 10b receives a signal input through the button input unit 10a, temporarily stores the received button information in the case of the connection setting protocol method, and, if reception is completed, meets the rules of the connection setting protocol method. The temporarily stored information is treated as message information and transmitted to the key phone system 20.

The digital interface unit 10d transmits the message information processed by the processor 10b according to the rules of the connection setting protocol method to the key phone system 20 and exchanges data in association with the key phone system 20.

At this time, the digital interface unit 10d is a kind of Digital Adapter for Subscriber Loops (hereinafter referred to as 'DASL') interface, and is capable of exchanging a received signal with an appropriate digital data format. The analog signal exchanged with the DTMF interface unit 22 is converted into a digital signal.

The signal converter 10e converts the information received from the processor 10b into a message of a connection setting protocol method.

5 is a flowchart illustrating a flow of a method of performing an extension exchange in a connection establishment protocol scheme according to a first embodiment of the present invention.

Hereinafter, a description will be given of a case where an extension subscriber makes a call connection request through an extension exchange function using a connection establishment protocol key phone terminal 10 according to an exemplary embodiment.

The extension subscriber transmits a call connection request message to the SIP interface unit 21 using the connection establishment protocol key terminal 10 (S20).

At this time, the call connection request message is received by the extension subscriber through the button input unit 10a of the connection establishment protocol key phone terminal 10, the phone number information, the processor 10b receives the temporary and stored in the storage unit 10c It stores it and transmits it to the signal converter 10e.

The signal conversion unit 10e processes the information received from the processor 10b in the form of an 'INVITE' message in the connection setting protocol method, and transmits the information to the digital interface unit 10d. The digital interface unit 10d receives the received information. The message 'INVITE' is transmitted to the connection setting protocol interface 21 of the key phone system 20.

The connection setting protocol interface unit 21 transmits a message received from the digital interface unit 10d to the message conversion unit 23.

The message converting unit 23 converts a message received from the connection setting protocol interface unit 21, that is, an 'INVITE' message into a signal that can be recognized by the control unit 24 of the key phone system 20.

The controller 24 analyzes a signal received from the message converter 23 (S 21).

At this time, the controller 24 analyzes the incoming telephone call included in the general header 51 of the received 'INVITE' message to determine the telephone number of the terminal to which the call is to be connected.

The controller 24 determines whether the incoming call number information is the extension terminal telephone number among the analyzed signals (S 22).

In other words, it is determined whether the terminal to which the call is to be connected is the SIP terminal 11.

As a result of determination, when the called telephone number is not the telephone number of the connection setting protocol terminal 11, that is, when the terminal to which the extension subscriber wants to make a call is not the extension terminal, the controller 24 corresponds to the identified called telephone number. The call connection with the external terminal is performed (S 23).

At this time, if it is determined whether the incoming telephone number is the trunk line terminal telephone number, and the control line 24 transmits the signal received by the PSTN interface unit 25, the PSTN interface unit 25 is public. The call network can be connected to the called terminal 31 through the telephone network 30.

When the called phone number is an Internet terminal, that is, a VoIP terminal 33, when the control unit 24 transmits a message signal received by the Internet interface unit 26, the Internet interface unit 26 connects to the Internet network 32. Through the call connection to the VoIP terminal 33 can be performed.

On the other hand, when the determination result indicates that the incoming telephone number information is the telephone number of the connection setting protocol terminal 11, that is, when the call connection is to be made by using the extension exchange function, the control unit 24 transmits the received signal to the message converting unit 23. To send).

The message converting unit 23 converts the received signal into an 'INVITE' message of the connection setting protocol method, and transmits it to the connection setting protocol terminal 11 (S 24).

In other words, the control unit 24 transmits the 'INVITE' message received from the connection setting protocol key phone terminal 10 to the connection setting protocol terminal 11 through the SIP interface 21 (S 24).

The connection setting protocol terminal 11 that receives the 'INVITE' message through the SIP interface 21 receives the '180 Ringing' message or the '200 OK' message, which is a return message signal for the 'INVITE' message signal. 21).

The SIP interface unit 21 transmits a '180 Ringing' message signal and a '200 OK' message signal received from the connection establishment protocol terminal 11 to the controller 24.

The controller 24 receives a return signal received through the SIP interface 21 (S 25).

The controller 24 retransmits the received return signal to the connection establishment protocol key phone terminal 10 which has requested a call connection (S26).

The connection establishment protocol key terminal 10 checks the received return message signal and transmits a final acknowledgment message 'ACK' message signal to the connection establishment protocol interface unit 21 (S 27).

After receiving the final acknowledgment message from the connection establishment protocol terminal 11, the key phone system 20 performs call setup between the terminals (S28).

In a state in which a call is connected, when an arbitrary terminal transmits a 'BYE' message signal, for example, the 'BYE' message, which is the call termination message signal, is connected to the connection establishment protocol keyphone terminal 10. The signal is transmitted (S 29).

The connection establishment key phone terminal 10 receiving the 'BYE' message signal transmits a '200 OK' signal, which is a message confirmation signal. Terminate the connected call (S 30).

The case where the call connection request message is received from the connection setting protocol key phone terminal 10 has been described. However, even when a call connection request message is received from the connection setting protocol terminal 11, the call connection can be performed in the same manner. have.

6 is a block diagram illustrating a configuration of a circuit switched network according to a second preferred embodiment of the present invention.

Referring to FIG. 6, the PSTN interface unit 25 and the Internet interface unit 26 are further included in the components of the key phone system 20 described in FIG. 3.

In addition, a receiving terminal 31 connected through the key phone system 20 and the public telephone network 30 and a VoIP terminal 33 connected through the Internet network 32 are further provided.

The PSTN interface unit 25 detects a signal received from the terminating terminal 31, which is an external trunk line terminal, via the public telephone network 30, and the connection setting protocol keyphone terminal 10 or the connection setting protocol terminal 11 When the terminal to which the call is to be connected is the called terminal 31 which connects to the external public telephone network 30, the terminal performs an interface function for performing a call connection with the corresponding terminal.

The Internet interface unit 26 receives a call connection request message received from an external VoIP terminal 33, and the terminal to which the extension terminal wants to make a call is a VoIP terminal 33 connected through the Internet network 32. In this case, it performs an interface function for performing a call connection with the corresponding terminal.

The terminating terminal 31 performs a function of allowing an external subscriber to receive a call connection request signal received through a trunk line and perform a call connection.

The VoIP terminal 33 performs a function of allowing an external subscriber to make a call connection using the voice over internet protocol method and enable a call.

VoIP refers to Internet Protocol telephony technology for a series of facilities that deliver voice information using the Internet protocol as the Voice over Internet Protocol.

In addition, Voice over Internet Protocol (VoIP) service is a service that delivers video, voice, and fax messages over the Internet. A user who wants to use the Internet accesses the Internet from a personal computer (PC) or has an independent Internet protocol. It is the transmission of real-time media such as voice and video in many cases, such as when using a device or when dialing a gateway from an existing public switched telephone network (PSTN) terminal.

In general, this means that voice information is sent digitally in discrete packets, rather than traditional protocols based on circuits such as PSTN networks, public telephone networks 30. H.323 and MGCP (Media Gateway) are representative protocols. Control Protocol) and Connection Setup Protocol.

Hereinafter, in the present invention, the VoIP terminal 33 refers to a terminal capable of making a call by performing a voice call connection request through the Internet network 32.

7 is a flowchart illustrating a flow of a method for providing extension service to an external subscriber according to a second preferred embodiment of the present invention.

Hereinafter, a case where an extension service providing request is received from an external VoIP terminal 33 is described as a preferred embodiment of the present invention.

The internet interface unit 26 receives the signal 'INVITE', which is a call connection request message, from the VoIP terminal 33 (S40).

In this case, the call connection request received from the VoIP terminal 33 will be described, for example, the 'INVITE' message of the connection establishment protocol method, but if the H.323 method is a call connection request message or a MGCP method call connection request message. Even if it does not depart from the scope of the present invention.

The internet interface unit 26 transmits the received message signal to the 'INVITE' message converter 23.

The message conversion unit 23 processes the 'INVITE' message signal received from the Internet interface unit 26 into a signal that can be recognized by the control unit 24 of the key phone system 20 and transmits the signal to the control unit 24.

The controller 24 analyzes the signal received from the message converter (S 41).

In other words, the control unit 24 analyzes the received signal to determine the incoming telephone number and to determine whether there is an extension service providing request (S 42).

As a result of determination, when there is a DI function request signal among the received signals, the controller 24 transmits a call connection request received from the extension service mode of the key phone system 20, that is, the external VoIP terminal 33, from the extension terminal. To provide the same service as when making a call connection request (S 43).

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and changes are possible within the technical spirit of the present invention, and such modifications and modifications belong to the appended claims.

As described above, according to the present invention, the call connection between any terminals uses a connection establishment protocol, thus eliminating the problem of numbness of the phone due to attenuation of the signal, and performing call setup, When there is a request for providing a function, that is, when there is an extension exchange function request from an extension terminal or a request for a function from an external terminal, it can be provided so that the advantages and exchange systems obtained when performing a call connection using a connection establishment protocol method can be provided. You can use all the basic functions of the effect.

Claims (9)

In the key phone system for relaying a call connection request signal between any terminal, A SIP interface unit for receiving a call connection request message signal of a connection establishment protocol method; A message conversion unit converting the call connection request message signal received through the SIP interface unit into a signal that can be recognized by a key phone system; Receiving the converted signal from the message conversion unit, grasps the receiving terminal telephone number of the received signal, converts the received signal to the called terminal telephone number to the call connection message signal of the connection setting protocol method and transmits Key phone system supporting a connection setting protocol method comprising a control unit. The method of claim 1, A key phone system that supports a connection establishment protocol method further comprising a DTMF interface unit supporting a dedicated communication method of the key phone system. The method according to claim 1 or 2, In connection with a public telephone network, when a terminal to which call is to be connected is a trunk line terminal, a key phone system supporting a connection establishment protocol method further comprising a PSTN interface unit for transmitting a call connection request signal to the corresponding terminal through a public telephone network. . The method according to claim 1 or 2, When the terminal to be connected to the Internet network, the terminal to be connected to the Internet terminal, a key phone system that supports the connection setting protocol method comprising an Internet interface for transmitting a call connection request message to the terminal via the Internet network. The method of claim 1, wherein the control unit, When a call connection request message signal is received from any external terminal, the received message signal is analyzed and, when there is an extension service providing request signal, a key phone supporting a connection establishment protocol scheme for providing an extension service function to the external terminal. system. The method of claim 1, wherein the message conversion unit, And a key establishment system supporting a connection establishment protocol scheme for converting a signal received from the controller into a call connection request message signal form of a connection establishment protocol scheme. Receiving a call connection request message signal of a connection establishment protocol method from any terminal; Converting the received call connection request message signal into a signal that can be recognized by a key phone system; Analyzing the converted signal to determine a called terminal number; Reconverting the converted signal into a message signal of a connection setting protocol method, and transmitting the converted signal to the determined called terminal number; Transmitting the message signal and performing a call setup between the respective terminals. The method of claim 7, wherein When the call connection request message signal of the connection establishment protocol method is received from an external terminal through any network, the call connection request message signal is analyzed to determine whether there is an extension service function request among the call connection request message signals. Judging, If the call result request signal is an extension service function request, the call establishment method that supports the connection establishment protocol method further comprises the step of providing a call service function to the external terminal, the call establishment method; . A button input unit for receiving call connection request message information from any subscriber; A processor for receiving message information from the button input unit, temporarily storing the received message information, and converting the received message information into a message signal of a connection setting protocol method; A storage unit which receives the message information from the processor and temporarily stores the message information; A signal converter configured to convert the received message information into a message signal of a connection setting protocol method under the control of the processor; And a digital interface unit receiving the converted message signal from the signal conversion unit and transmitting the message signal.