VoIP gateway device, control method thereof and VoIP

Provided are a Voice over Internet Protocol (VoIP) gateway device, a control method thereof, and a VoIP gateway system. The VoIP gateway device includes: a connector which is connected to a first terminal; a communication unit which communicates with a proxy server that relays a VoIP communication; a storage unit which stores a ringtone corresponding to a call received by a call back function; and a controller which transmits an invite message to the proxy server for connecting a call from a first terminal to a second terminal corresponding to the call back function upon request from the first terminal for the call back function, and transmits the stored ringtone to the first terminal upon receiving a ringing message from the proxy server in response to the invite message.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2011-0140278, filed on Dec. 22, 2011 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Apparatuses and methods consistent with exemplary embodiments relate to a Voice over Internet Protocol (VoIP) gateway device, a control method thereof, and a VoIP gateway system, and more particularly, to a VoIP gateway device, a control method thereof and a VoIP gateway system which provides a call back service.

2. Description of the Related Art

Voice over Internet Protocol (VoIP) relates to a set of communication service technologies which performs fax transmission/reception or voice calls such as telephone calls in a general telephone network (e.g., a Public Switched Telephone Network (PSTN)) by converting voice or fax data into a data packet of the Internet Protocol in a computer network.FIG. 1illustrates a related art VoIP system. As shown therein, a sender terminal and a receiver terminal are VoIP terminals, and a proxy server relays VoIP communications between the sender terminal and the receiver terminal. If the sender terminal transmits an invite message to the proxy server to request a call connection to the receiver terminal, the proxy server transmits the invite message to the receiver terminal (201). If the receiver terminal is busy and unavailable to receive the call, the proxy server reports the same to the sender terminal (201). In this case, the sender terminal may register a call back service with the proxy server (202). Once the call back service is registered, the proxy server identifies the state of the receiver terminal and reports an available time to the sender terminal (203). In response to such a report, the sender terminal again transmits the invite message to the receiver terminal through the proxy server (204).

In the related art, to use the call back service which is provided for the case where a call connection requested by the sender is not available due to the receiver's circumstances, the proxy server should perform the call back function, or software of the proxy server should be changed. VoIP is based on session initiation protocol (SIP), according to which only a call service for a failure to connect an outgoing call is defined, but a call service for a failure to receive an incoming call is not defined. If the state of the receiver terminal is not identifiable at the time when the proxy server performs the call back function, notify ring timeout occurs and no report is made to the sender terminal.

SUMMARY

Accordingly, aspects of one or more exemplary embodiments provide a VoIP gateway device, a control method thereof and a VoIP gateway system which provides a call back function without changing software of a proxy server to thereby reduce load on the proxy server.

Aspects of one or more other exemplary embodiments provide a VoIP gateway device, a control method thereof and a VoIP gateway system which not only provides a call back function for a failure to request for an outgoing call but also provides a call back function for a failure to receive an incoming call.

Aspects of one or more other exemplary embodiments provide a VoIP gateway device, a control method thereof and a VoIP gateway system which provides a ringtone for a call received by a call back function to be distinguished from other general calls.

According to an aspect of an exemplary embodiment, there is provided a VoIP gateway device including: a connector which is connected to a first terminal; a communication unit which communicates with a proxy server that relays a VoIP communication; a storage unit which stores a ringtone corresponding to a call received by a call back function; and a controller which transmits an invite message to the proxy server for connecting a call from the first terminal to a second terminal corresponding to the call back function upon request from the first terminal for the call back function, and transmits the stored ringtone to the first terminal upon receiving a ringing message from the proxy server in response to the invite message.

The call back function may be a function which is requested by the first terminal if a call connection requested by the first terminal to the second terminal fails.

The call back function may be a function which is requested by the first terminal if a call is not made as a result of the first terminal's failure to respond to a request made by the second terminal for the call connection.

The stored ringtone may be different from a ringtone for a call generally received by the first terminal.

The controller may not transmit any message to the first terminal if the controller does not receive a ringing message in response to the invite message from the proxy server.

The controller may transmit the stored ringtone to the first terminal to report that the call back function is being performed if the invite message is transmitted to the proxy server.

According to an aspect of another exemplary embodiment, there is provided a VoIP system including: a proxy server which relays a VoIP communication; and a VoIP gateway device which includes a connector connected to a first terminal, a communication unit communicating with the proxy server, a storage unit storing a ringtone corresponding to a call received by the call back function, and a controller transmitting an invite message to the proxy server to connect a call from the first terminal to a second terminal corresponding to the call back function upon request from the first terminal for the call back function, and transmitting the stored ringtone to the first terminal upon receiving a ringing message from the proxy server in response to the invite message.

The call back function is requested by the first terminal if a call connection requested by the first terminal to the second terminal fails.

The call back function may be requested by the first terminal if a call is not made as a result of the first terminal's failure to respond to the request for the call connection by the second terminal.

The stored ringtone may be different from a ringtone for a call generally received by the first terminal.

The controller may not transmit any message to the first terminal if the controller does not receive the ringing message in response to the invite message from the proxy server.

The stored ringtone may be transmitted to the first terminal to report that the call back function is being performed if the invite message is transmitted to the proxy server.

According to an aspect of another exemplary embodiment, there is provided a control method of a VoIP gateway device, the control method including: storing a ringtone corresponding to a call received by a call back function; transmitting to a proxy server an invite message to connect a call from a first terminal to a second terminal corresponding to the call back function if the call back function is requested by the first terminal; and transmitting the stored ringtone to the first terminal if a ringtone message is transmitted by the proxy server in response to the invite message.

The call back function may be requested by the first terminal if the first terminal requests the call connection to the second terminal but the call connection is not made.

The call back function may be requested by the first terminal if a call connection is not made as the first terminal fails to respond to a request of the second terminal for the call connection.

The stored ringtone may be different from a ringtone for a call generally received by the first terminal.

The control method may further include transmitting the invite message to the proxy server until the ringing message is received, without transmitting any message to the first terminal, if the ringing message is not received from the proxy server in response to the invite message.

The control method may further include transmitting the stored ringtone to the first terminal to report that the call back function is being performed if the invite message is transmitted to the proxy server.

According to an aspect of another exemplary embodiment, there is provided a control method of a VoIP gateway device, the control method including: receiving, by the VoIP gateway device, a request from a first terminal for a call back function; and transmitting, to a proxy server that relays a VoIP communication between the first terminal and a second terminal, an invite message to connect a call, corresponding to a call back function, to the second terminal in response to the received request.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 2is a block diagram of a VoIP system according to an exemplary embodiment. As shown therein, the VoIP system includes a VoIP gateway device100, a proxy server200, a VoIP terminal300and a second terminal400.

The VoIP gateway device100may process a call for VoIP communication according to session initiation protocol (SIP). The VoIP gateway device100according to the present exemplary embodiment may include a multimedia terminal adaptor (MTA) in a cable network, or an Internet access device (IAD) in an xDSL network to process the call for the VoIP communication. The MTA performs a conversion operation to convert a data signal into a voice signal, and enables a normal telephone to perform VoIP communication. As a kind of asymmetric digital subscriber line (ADSL) modem, the IAD is a composition modem including an Ethernet port and provides VoIP, Voice over DSL (VoDSL), wireless, Bluetooth, packet loss concealment (PIC), and Home Phoneline Networking Alliance (HomePNA) services and has an Internet set-top box function. Accordingly, a user may use the IP communication service through the IAD.

The proxy server200relays communications between the receiver terminal and the sender terminal in the Internet network, and includes a protocol controller. The proxy server200may be realized as session initiation protocol (SIP)-proxy server or H.323-gate keeper, though it is understood that one or more other exemplary embodiments are not limited thereto. The proxy server200stores therein information of subscriber terminals, and relays communication between the sender terminal and the receiver terminal by using the information.

The first and second terminals300and400may be realized as VoIP telephones, normal telephones, mobile phones, computers, tablets, etc. The VoIP telephone is used for a voice call through VoIP communication. The VoIP telephone may be realized as a PC, a VoIP exclusive telephone, a video phone, or a monitor having a video phone function. Otherwise, hardware and software modules for VoIP communication may be installed in a PC, which is connected to the Internet phone.

As described above with reference toFIG. 1, a related art VoIP terminal should register a call back service for a failure to connect a call with the related art proxy server, adding load on the related art proxy server. Failure to connect a call via the call back service due to continued telephone calls of the second terminal400may cause a ring timeout, and the related art proxy server does not subsequently provide the call back function. The related art proxy server defines only the call back function for an outgoing call, but does not define an incoming call back function.

The VoIP gateway device100according to the present exemplary embodiment solves the problem of the related art proxy server. The call back function of the VoIP terminal300is registered with the VoIP gateway device100instead of the proxy server200. As the VoIP gateway device100leads the performance of the call back function, the proxy server200has a reduced load as the proxy server200relays VoIP communication without managing a call back function. The VoIP gateway device100according to the present exemplary embodiment provides a call back function for a failure to receive an incoming call as well as a call back function for a failure to request for an outgoing call, thereby enhancing a user's convenience. The VoIP gateway device100according to the present exemplary embodiment transmits, to the VoIP terminal300, a ringtone that is different from a ringtone for calls generally received by the terminal300to thereby notify a user of a call received by the call back function.

Hereinafter, the VoIP gateway device100according to the present exemplary embodiment will be described in more detail.

The VoIP gateway device100includes a connector110, a communication unit120, a storage unit130, and a controller140.

The connector110is connected to the first terminal300and processes an outgoing call or an incoming call from the first terminal300by VoIP communication.

The communication unit120communicates with the proxy server200which relays the VoIP communication. The communication unit120may communicate with the proxy server200via the Internet or cable modem termination system (CMTS). The CMTS converts cable modem data into a data packet for transmission via the Internet, and is capable of communicating with the proxy server200via the Internet. If communication is performed via the CMTS, the communication unit120is realized as a radio frequency (RF) cable interface and receives voice or a fax packet through the CMTS and transmits the received packet to the first terminal300. The CMTS may be a head-end device that is compatible with data over cable interface specification (DOCSIS) 3.0.

The storage unit130stores therein a ringtone corresponding to a call received by the call back function. The ringtone corresponding to the call received by the call back function is different from a ringtone corresponding to an incoming call that is received generally. Accordingly, through the ringtone, a user may identify whether a received call is a general incoming call or a call received by the call back function. This enhances the user's convenience.

The storage unit130stores therein not only the ringtone, but also various types of other tones. The other tones may include a dial tone which is heard when a receiver is picked up, a ring back tone which is provided to inform a caller that a ringing tone signal is transmitted to the receiver upon request for an outgoing call, and a busy tone which is provided to inform a caller that a receiver is on the phone upon request for an outgoing call.

Upon request from the first terminal300for a call back function, the controller140transmits an invite message to the proxy server200to connect a call to the second terminal400to which the first terminal300desires to connect the call, corresponding to the call back function. Upon receiving a ringing message from the proxy server200corresponding to the invite message, the controller140transmits the stored ringtone to the first terminal300. The control operation of the controller140will be described in detail with reference toFIGS. 3 to 6.

Upon receiving a request for a call back function for the failure to make an outgoing call of the first terminal300, the controller140may have the following default values as environment variables to perform the call back function.

Upon receiving a request for a call back function for the failure to receive an incoming call of the first terminal300, the controller140may have the following default values as environment variables to perform the call back function.

FeaturesAutoRedialInterval defines an interval at which the VoIP gateway device100tries to make a redial to the second terminal400in response to the request for the call back function by a control of the controller140. In the present exemplary embodiment, 15 seconds is set as a default value, though it is understood that this value may vary in other exemplary embodiments. FeaturesAutoRedialTimeout defines the maximum time value for which the VoIP gateway device100does not tries to make a call by the call back function by a control of the controller140. 1800 seconds is set as a default value in the present exemplary embodiment, though it is understood that this value may vary in other exemplary embodiments. FeaturesAutoRedialNotiFingTimeout is a time interval at which making a call is reported to the first terminal300by the call back function. If the value is 0, no report is made. If the value is 1, a timer is commenced after ringing. Ten seconds are set as a default value in the present exemplary embodiment, though it is understood that this value may vary in other exemplary embodiments. FeaturesVscAutoRedialActive defines vertical service code (VSC) to activate an automatic redial by the call back function. FeaturesAdminStatusAutoRedial defines a value set by a user to use the call back function. FeaturesAutoRedialNotiUserFirst defines the value which notifies that a call is sent by the call back function through the ringtone stored in the storage unit130to the first terminal300at the same time as an attempt to make a call to the second terminal400by the call back function.

FIGS. 3 and 4are flowcharts of the call back function for an outgoing call of the first terminal300according to one or more exemplary embodiments.FIGS. 5 and 6are flowcharts for the call back function for an incoming call to the first terminal300according to one or more exemplary embodiments.

FIG. 3illustrates an example in which no message is transmitted to the first terminal300if a call is not successfully connected (if a ringing message is not transmitted by the proxy server) upon request from the VoIP gateway device100for the call by the call back function in the case where the first terminal300requests the call to the second terminal400.

As shown inFIG. 3, at operation501, if a user picks up the receiver to request a call through the first terminal300(off-hook), the VoIP gateway device100transmits a dial tone to the first terminal300, and the first terminal300dials a telephone number. The VoIP gateway device100transmits the invite message to the proxy server200to connect a call corresponding to the telephone number input by the first terminal300. The proxy server200transmits the invite message to the counterpart terminal (second terminal400). However, if the call connection fails, e.g., because the second terminal400is busy or for other reasons, the second terminal400transmits a busy message (e.g., an SIP 486 Busy Here message) to the proxy server200, and the proxy server200transmits the busy message to the VoIP gateway device100. The VoIP gateway device100transmits a busy tone as a ring back tone corresponding to the busy message 486 so that a user recognizes the busy tone and puts down the receiver (on-hook).

If a user makes an outgoing call request but such a call fails at operation501, the call back function may be registered at operation502. Thus, a user may pick up the receiver (off-hook) through the first terminal300, and register the call back function with the VoIP gateway device100via the VSC (Dial). The VoIP gateway device100transmits an invite message to the proxy server200in response to a user's request for the call back function. However, even in this case, upon receiving the busy message from the second terminal400, the proxy server200transmits the message to the VoIP gateway device100, which transmits a busy tone as a ring back tone corresponding to the busy message so that a user recognizes the busy tone and puts down the receiver (on-hook).

At operation503, following the default value defined by “FeatureAutoRedialInterval” as in Table 1, the controller140does not report to a user and transmits the invite message to the proxy server200again in response to a user's request for the call back function, to thereby make a call. Upon receiving the busy message from the proxy server200for the invite message, the VoIP gateway device100cancels and ends the call. At this operation, the VoIP gateway device100makes no report if the call is not sent to the second terminal400or the call is sent but not connected, by the call back function.

At operation504, the controller140of the VoIP gateway device100transmits to the proxy server200the invite message in response to a user's request for the call back function at an interval of the default value defined by “FeatureAutoRedialInterval” in Table 1. The proxy server200transmits the invite message to the second terminal400. Upon receiving a ringing message (e.g., an SIP 180 ringing message) from the second terminal400, the proxy server200transmits the ringing message to the VoIP gateway device100. The VoIP gateway device100transmits a different ringtone with respect to the call received by the call back function, corresponding to the ringing message. By the ringtone corresponding to the call received by the call back function, a user recognizes that the call is in accordance with the call back function as opposed to a general call, and picks up the receiver for the call (off-hook). According to the Real-time Transport Protocol (RTP) session, the first terminal300and the second terminal400are successfully connected for the call.

FIG. 4illustrates an exemplary embodiment in which the first terminal300requests a call to the second terminal400. Unlike the exemplary embodiment illustrated inFIG. 3, the exemplary embodiment illustrated inFIG. 4is a case where a request for the call is reported to the first terminal300when the VoIP gateway device100requests for the call by the call back function.

As shown inFIG. 4, the operation601is similar to the operation501inFIG. 3. The operation602is similar to the operation502inFIG. 3. At operation603, following the default value defied by “FeatureAutoRedialInterval” in Table 1, the controller140of the VoIP gateway device100transmits the invite message to the terminal (e.g., the second terminal400) to which the first terminal300desires to connect the call through the proxy server200in response to the request for the call back function through the first terminal300at operation602, and transmits to the first terminal300the ringtone stored in the storage unit130to inform that the call is made to the second terminal400by the call back function. The ringtone stored in the storage unit130is different from ringtones for general incoming calls, and a user may recognize the ringtone by the call back function. Accordingly, a user picks up the receiver (off-hook). If the counterpart terminal (second terminal400) is busy with respect to the invite message, the second terminal400transmits the busy message to the proxy server200. The proxy server200transmits the busy message 486 to the VoIP gateway device100. The VoIP gateway device100transmits the busy tone to the first terminal300corresponding to the busy message. Accordingly, a user puts down the receiver to end the call. At operation604, the controller140transmits the invite message to the proxy server200to connect the call in response to the request for the call back function at the interval of the default value defined by “FeatureAutoRedialInterval” in Table 1, and transmits the different ringtone to the first terminal300to notify that the call is being sent by the call back function. If a user picks up the receiver listening to the ringtone according to the call back function and receives a ringing message (e.g., an SIP 180 ringing message) corresponding to the invite message from the proxy server200, the VoIP gateway device100transmits the ring back tone to the first terminal300to notify the connection of the call. The first terminal300and the second terminal400are connected for the call by the RTP session to thereby connect the call.

FIG. 5illustrates an example of transmitting no report message to the first terminal300if a call is not successfully connected upon request from the first terminal300for the call back function to the VoIP gateway device100as the first terminal300fails to receive a call request from the second terminal400.

At operation701, the invite message of the second terminal400is transmitted to the VoIP gateway device100through the proxy server200, and the VoIP gateway device100transmits the ringtone corresponding to a general incoming call to the first terminal300. If the call is not connected due to a user's absence or by other reasons, the second terminal400cancels and ends the call. Regarding the call received when a user is absent, if the call back function is requested by the first terminal300to the VoIP gateway device100according to the VSC, the VoIP gateway device100transmits the invite message to the proxy server200to connect the call to the second terminal400at operation702. However, even in this case, upon receiving a busy message (e.g., an SIP 486 busy message) from the second terminal400, the proxy server200transmits the message to the VoIP gateway device100, and transmits the busy tone as a ringtone corresponding to the busy message. A user recognizes the ringtone and puts down the receiver.

At operation703, the controller140transmits the invite message to the proxy server200in response to the request for the call back function at the default value defined by “FeatureAutoRedialInterval” in Table 2. Upon receiving the busy message again from the proxy server200with respect to the invite message, the VoIP gateway device100cancels and ends the call. At this stage, the VoIP gateway device100makes no report to the first terminal300.

At operation704, the controller140of the VoIP gateway device100transmits the invite message to the proxy server200again according to the call back function at the interval of the default value defined by “FeatureAutoRedialInterval” in Table 2. The proxy server200transmits the invite message to the second terminal400. Upon receiving the ringing message (e.g., an SIP 180 ringing message) from the second terminal400, the proxy server200transmits the ringing message to the VoIP gateway device100. The VoIP gateway device100transmits a different ringtone corresponding to the call received according to the request for the call back function with respect to the ringing message. By the ringtone corresponding to the call received according to the call back function, a user recognizes that such a call is not a call generally received, but received according to the call back function and picks up the receiver (off-hook). The first terminal300and the second terminal400are successfully connected for the call according to the RTP session.

FIG. 6illustrates an example of the first terminal's failure to receive the call even though the second terminal400requests the call to the first terminal300. UnlikeFIG. 5, however,FIG. 6illustrates an example of reporting to the first terminal300the request for the call when the VoIP gateway device100requests the call according to the call back function.

At operation803, the controller140of the VoIP gateway device100transmits the invite message to the terminal (e.g., the second terminal400) to which the first terminal300desires to connect a call through the proxy server200at the default value defined by “FeatureAutoRedialInterval” in Table 1 according to the request for the call back function by the first terminal300made at operation802. The controller140transmits the different ringtone stored in the storage unit130to the first terminal300to notify the first terminal300that the call is being sent according to the call back function. The ringtone stored in the storage unit130is different from a ringtone for general incoming calls, and a user may recognize that such a ringtone is provided according to the call back function and picks up the receiver (off-hook). If the counterpart terminal (the second terminal400) is busy with respect to the invite message, the second terminal400transmits the busy message to the proxy server200, and the proxy server200transmits the busy message 486 to the VoIP gateway device100. The VoIP gateway device100transmits the busy tone to the first terminal300corresponding to the busy message, and a user puts down the receiver (on-hook) to end the call. At operation804, the controller140transmits the invite message to the proxy server200to connect the call according to the request for the call back function at the interval of the default value defined by “FeatureAutoRedialInterval” in Table 2, and transmits a different ringtone stored in the storage unit130to the first terminal300to notify that the call is being sent according to the call back function. As the ringtone is provided according to the call back function, a user picks up the receiver (off-hook). Upon receiving the ringing message (e.g., an SIP 180 ringing message) from the proxy server200corresponding to the invite message, the VoIP gateway device100transmits the ring back tone to the first terminal300to notify a user of the connection of the call. The first terminal300and the second terminal400are successfully connected for the call by the RTP session.

As described above, a VoIP gateway device, a control method thereof, and a VoIP gateway system according to exemplary embodiments provide a call back function without change of software of a proxy server to thereby reduce a load on the proxy server.

Also, the VoIP gateway device, the control method thereof, and the VoIP gateway system according to the exemplary embodiments provide not only a call back function for a failure to request an outgoing call but also a call back function for a failure to receive an incoming call.

Further, the VoIP gateway device, the control method thereof, and the VoIP gateway system according to exemplary embodiments provide a ringtone that is distinguishable from a ringtone for a call generally received to thereby enhance a user's convenience.

Although a few exemplary embodiments have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the present inventive concept, the range of which is defined in the appended claims and their equivalents.