KR20080113678A - System and method for call processing - Google Patents

Abstract

A call processing system and a method thereof in case a call session based on IMS is abnormally terminated are provided to prevent charging leakage phenomenon by unreasonably maintaining a media connection by terminating a media connection corresponding to the abnormally terminated call session. A call session is formed. The call session is terminated in a state in which a first message demanding a termination about the call session is not received(S510). A second message demanding the termination of the media connection corresponding to the call session is outputted(S520). A media processing server includes one of an application server and a multimedia resource apparatus.

Description

System and method for call processing

1 is a diagram illustrating an internet protocol multimedia subsystem according to an embodiment of the present invention.

2 is a flowchart illustrating a subscriber registration process according to an embodiment of the present invention.

3 is a flowchart illustrating a call processing process of an originating IMS according to an embodiment of the present invention.

4 is a flowchart illustrating a call processing procedure of a called party IMS according to an embodiment of the present invention.

5 is a flowchart illustrating a call processing process of an originating IMS when a call session is abnormally terminated according to an embodiment of the present invention.

6 is a flowchart illustrating a call processing process of a receiving IMS when a call session is abnormally terminated according to an embodiment of the present invention.

7 is a flowchart illustrating a call processing process of an originating IMS when a call session is abnormally terminated according to an embodiment of the present invention.

8 is a flowchart illustrating a call processing process of an originating IMS when a call session is abnormally terminated according to another embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

110: CSCF 112: P-CSCF

114: I-CSCF 116: S-CSCF

120: HSS 130: media processing server

The present invention relates to an Internet Protocol Multimedia Subsystem (IMS), and more particularly, to call processing when an IMS-based call session ends abnormally.

With the development of mobile communication, the spread of various high quality multimedia services using mobile terminals is increasing. Recently, technologies for internet multimedia services based on IP based core networks have been developed. As an example, the 3rd Generation Partnership Project (3GPP) is working on standardizing ALL IP based core networks to provide IP based multimedia services.

In the ALL IP-based core network proposed in 3GPP, basic and major processes for call processing are performed by IMS. In IMS, call processing and media stream processing are separated. For this reason, after the session is normally established, a problem may occur in the call processing operation and a situation in which the processing operation of the media stream may continue even if the call session is terminated. Therefore, there is a need for a description of call processing when an IMS-based call session ends abnormally.

An object of the present invention is to terminate a media stream processing task corresponding to a terminated call session when an IMS-based call session ends abnormally.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a call processing method according to an embodiment of the present invention is to form a call session, and the call session is terminated in the state that the first message requesting termination for the call session is not received. If so, outputting a second message requesting termination of a media connection corresponding to the call session.

In order to achieve the above object, a call processing method according to an embodiment of the present invention manages the call session when the call session is terminated without receiving a first message requesting termination of the call session from a terminal. Outputting a second message requesting termination of a media connection corresponding to the call session by the call session controlling apparatus; and terminating the media connection by the media processing server receiving the second message.

In order to achieve the above object, a call processing system according to an embodiment of the present invention forms a call session according to a request of a terminal, and the call session without receiving a first message requesting termination of the call session. Is terminated, the call session control device for outputting a second message requesting the termination of the media connection corresponding to the call session, and the media connection is formed, and if the second message is output, terminate the media connection. And a media processing server.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

1 is a diagram illustrating an Internet Protocol Multimedia Subsystem (IMS 100) according to an embodiment of the present invention. The illustrated IMS 100 includes a call session control function (CSCF 110), a home subscriber server (HSS 120), and a media processing server 130.

The CSCF 110 may perform basic functions for session initiation protocol (SIP) based session control such as subscriber registration, authentication, service triggering, routing, various call control, address handling, and the like. The CSCF 110 includes a proxy CSCF (P-CSCF 112), an interrogating-CSCF (I-CSCF 114), and a serving CSCF (S-CSCF 116). )).

P-CSCF 112 is the first point where terminal 140 connects to IMS 100. When a registration request message (REGISTER) is transmitted from the terminal 140, the P-CSCF 112 delivers it to the I-CSCF 114. The P-CSCF 112 stores the address of the S-CSCF 116 assigned by the I-CSCF 114 in the process of processing a registration request message, and then receives an session request message (INVITE) from the terminal 140. If so, it can be forwarded to the S-CSCF 116.

The I-CSCF 114 serves as a contact point for incoming calls to connect to subscriber stations in the network and a contact point with terminals of other network subscribers roaming in the network. The I-CSCF 114 obtains the address of the S-CSCF available from the HSS 120 during registration of the subscriber (user of the terminal 140) and refers to the S-CSCF 116 to be in charge of actual registration. Can be assigned.

The S-CSCF 116 may register a subscriber with the HSS 120 when the registration request message is received from the I-CSCF 114 and obtain a service profile of the subscriber from the HSS 116. In addition, when the S-CSCF 116 receives the session request message of the terminal 140, the S-CSCF 116 checks the type of service to be provided to the terminal 140 using the service profile and processes the identified service. ) Can be triggered (service triggering).

The HSS 120 is a subscriber's master database, which stores and manages profile information, authentication and location related data, and provides information required by the I-CSCF 114 or the S-CSCF 116. In addition, the HSS 120 may include a function of a home location register (HLR).

The media processing server 130 may provide various kinds of multimedia services. An example of a multimedia service is a video call service. In order to support a video call service, the media processing server 130 may relay a media stream between terminals. Of course, the media processing server 130 may also provide a Voice over Internet Protocol (VoIP) service, a Video On Demand (VOD) service, an Instant Message (IM) service, or the like, which the media processing server 130 provides. The present invention is not limited by the kind of multimedia service that can be performed.

When providing a multimedia service, the media stream transmitted by the media processing server 130 to the terminal 140 or received from the terminal 140 may include at least one of video data, audio data, text data, and other programming documents. The type of data included in the media stream may vary depending on the type of multimedia service provided by the media processing server 130.

The media processing server 130 may include at least one of an application server (AS, not shown) and a multimedia resource function (MRF, not shown). The AS holds the service logic and can manage the type of service to provide to the subscriber. The MRF may directly process a media stream in conjunction with an AS. AS and MRF may follow the 3rd Generation Partnership Project (3GPP) IMS standard.

1 shows a P-CSCF 112, an I-CSCF 114, an S-CSCF 116, an HSS 120, and a media processing server 130 one by one, but this is the basic configuration of the IMS 100. Since it is intended to illustrate the present invention is not limited thereto. Accordingly, the IMS 100 may include a plurality of devices or servers shown in FIG. 1. In addition, although not shown in FIG. 1, the terminal 140 includes a mobile communication network such as Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Global System for Mobile communication (GSM), a Public Switched Telephone Network (PSTN), It may be connected to the IMS 100 via a wired communication network such as an Integrated Services Digital Network (ISDN), or other known communication network.

In order to provide an IMS 100 based multimedia service according to an embodiment of the present invention, the CSCF 110 may establish and manage a call session of the terminal 140, and the media processing server 130. ) May form and manage a media connection with the terminal 140 as the call session is formed. In this case, the call session is processed through a series of control / request / response messages (preferably Session Initiation Protocol (SIP) based messages) and the terminal 140 and the media processing server 130 or the terminal 140. It may mean a communication path established between other terminals (not shown). In addition, the media connection may mean a media stream transport channel that is triggered as a call session is established.

In order to receive a multimedia service through the IMS 100, the terminal 140 may perform a task of registering a subscriber to the IMS 100, which is illustrated in FIG. 2.

The terminal 140 may transmit a registration request message to the P-CSCF 112 (S210). The registration request message may include a Uniform Resource Identifier (hereinafter referred to as a destination URI) indicating a destination domain, a URI of the terminal 140, an IP address of the terminal 140, and the like.

After receiving the registration request message from the terminal 140, the P-CSCF 112 may perform a DNS (Domain Name System) query operation (S215). Through the DNS query operation, the P-CSCF 112 may obtain the address of the I-CSCF 114. More specifically, in the DNS query operation, the P-CSCF 112 may transmit a DNS query message including a destination URI of the registration request message received from the terminal 140 to a DNS (not shown). . At this time, the DNS selects an appropriate I-CSCF 114 by referring to a destination URI included in the DNS query message, and DNS is configured to generate a DNS query response message including an address of the selected I-CSCF 114. May transmit to the P-CSCF 112.

The P-CSCF 112 having obtained the address of the I-CSCF 114 may transmit a registration request message of the terminal 140 to the I-CSCF 114 (S220). The registration request message transmitted to the I-CSCF 114 may be a compilation of the registration request message received by the P-CSCF 112 from the terminal 140. Here, editing is a concept that includes adding, deleting, and changing information. For example, the registration request message sent to the I-CSCF 114 may include the address of the P-CSCF 112. An example of the address of the P-CSCF 112 is the URI of the P-CSCF 112. The address of the P-CSCF 112 may be used as a routing path when the S-CSCF 116 later wants to send a message to the terminal 140.

Upon receiving the registration request message from the P-CSCF 112, the I-CSCF 114 transmits a user authorization request (UAR) message to the HSS 120 (S225). The UAR message may include information about the capability of the terminal 140. Although omitted in FIG. 2, the operation of obtaining the address of the HSS 120 by the I-CSCF 114 may be performed before the process S225. Here, the I-CSCF 114 may obtain the address of the HSS 120 from an SLF (Server Locator Function, not shown).

The HSS 120 selects the S-CSCF 116 suitable for the capability of the terminal 140 by referring to the UAR message transmitted from the I-CSCF 114 and includes information about the selected S-CSCF 116. A user authorization answer message (UAA) message may be transmitted to the I-CSCF (S230) (S230).

The I-CSCF 114 may select the S-CSCF 116 to process the registration request of the terminal 140 through the UAR message. If the S-CSCF 116 is confirmed, the I-CSCF 114 may transmit a registration request message to the S-CSCF 116 (S235).

Thereafter, the S-CSCF 116 may transmit a Server Assignment Request (SAR) message to the HSS 120 (S240).

The HSS 120 may transmit a Server Assignment Answer (SAA) message to the S-CSCF 116 as a response to the SAR message (S245). The SAA message may include the service profile of the user of the terminal 140, that is, the subscriber. The service profile may include various kinds of known information required to provide a service. For example, the service profile may include information on which multimedia service the subscriber subscribes to.

Upon receiving the SAA message, the S-CSCF S116 may store a service profile and transmit a 200 OK response message to the I-CSCF 114 (S250). The 200 OK response message may include the address of the S-CSCF 116. An example of the address of the S-CSCF 116 may be a URI of the S-CSCF 116.

The I-CSCF 114 may transmit a 200 OK response message to the P-CSCF 112 (S255). At this time, the P-CSCF 112 may store the address of the S-CSCF 116 included in the 200 OK response message. Of course, the manner in which the P-CSCF 112 obtains the address of the S-CSCF 116 is not limited thereto. For example, an embodiment in which the P-CSCF 112 obtains the address of the S-CSCF 116 from the I-CSCF 114 or the S-CSCF 116 is also possible.

Thereafter, the P-CSCF 112 may transmit a 200 OK response message to the terminal 140 (S260).

After completing the registration process as shown in FIG. 2, the P-CSCF 112 may know the address of the S-CSCF 116 that will process the request of the terminal 140, and the S-CSCF 116 may determine the terminal. It is possible to retain the service profile of 140 and the routing path (address of P-CSCF 112) of terminal 140.

Hereinafter, a session establishment process for a multimedia service will be described in more detail. In the present specification, a session for a multimedia service is a concept including both the aforementioned call session and media connection. That is, the session establishment may mean that both the call session and the media connection are established. For convenience of description, the terminal requesting the session establishment is called a "source terminal" and the IMS for processing a message output from the source terminal is called a "calling party IMS". In addition, a terminal that is a communication target of the source terminal is referred to as a destination terminal, and an IMS that processes a message to be sent to a destination terminal is called a destination IMS. The calling IMS and the called IMS may be the same IMS physically or logically or may be different IMS.

3 is a flowchart illustrating a call processing process of an originating IMS according to an embodiment of the present invention.

The source terminal 140-1 wishing to communicate with the destination terminal may transmit a session request message to the P-CSCF 112-1 (S310). The session request message may be a SIP based INVITE message.

When the session request message is received from the source terminal 140-1, the P-CSCF 112-1 may transmit a 100 Trying response message to the source terminal 140-1 (S315). If the source terminal 140-1 has completed the subscriber registration operation as illustrated in FIG. 2, the P-CSCF 112-1 may process the session request message of the source terminal 140-1. 116-1). If the address of the S-CSCF 116-1 is confirmed, the P-CSCF 112-1 may transmit a session request message to the S-CSCF 116-1 (S320).

When the session request message is transmitted from the P-CSCF 112-1, the S-CSCF 116-1 transmits a 100 Trying response message to the P-CSCF 112-1 (S325), and the source terminal 140-. The service profile of 1) may be searched for (S330). According to an embodiment of the present invention, the S-CSCF 116-1 extracts subscriber information of the source terminal 140-1 from the session request message sent from the P-CSCF 112-1, and extracts the subscriber information. The service profile corresponding to the information may be searched for.

When the service profile of the source terminal 140-1 is found, the S-CSCF 116-1 can identify a multimedia service to be provided to the source terminal 140-1, and a media processing server ( In operation S335, service triggering may be performed. This process may be understood as the process of requesting the media processing server 130 from the S-CSCF 116-1 to provide a specific multimedia service to the source terminal 140-1.

The media processing server 130 may prepare to provide a multimedia service (S340), and transmit a response message indicating that it is ready to provide the multimedia service to the S-CSCF 116-1 (S345).

Meanwhile, the S-CSCF 116-1 may transmit a session request message to an S-CSCF (not shown) of the called party's IMS (S350). Of course, the session request message does not have to be sent directly from the S-CSCF 116-1 to the S-CSCF of the destination IMS, but may be relayed through another device or server.

If a positive response (hereinafter referred to as session response message) to the session request is received from the called party's IMS (S355), the S-CSCF 116-1 may transmit it to the P-CSCF 112-1 (S360). ). In addition, the P-CSCF 112-1 may forward the session response message to the source terminal 140-1 (S365).

Through step S310 to step S365, a call session between the source terminal 140-1 and the destination terminal can be established. When the call session is established, the media processing server 130 forms a media connection with the source terminal 140-1. It may be (S370). In this case, the media processing server 130 may receive the media stream from the source terminal 140-1 or transmit the media stream to the source terminal 140-1.

Although not shown, while the media connection is maintained, the source terminal 140-1 sends a session keep-up message (eg, a re-INVITE message) to the P-CSCF 112-1 confirming that the session is ongoing. Can be. In addition, the P-CSCF 112- may forward this to the S-CSCF 116-1, which maintains the session of the source terminal 140-1 through a session keep-alive message. You can.

When terminating the multimedia service, the source terminal 140-1 may transmit a session end message (eg, a BYE message) to the P-CSCF 112-1. The P-CSCF 112-1 may transmit a session termination message to the S-CSCF 116-1, which may transmit it to the media processing server 130. Of course, the session end message may be delivered to the destination terminal via the called party IMS. Through this, the session (call session and media connection) requested by the source terminal 140-1 may be normally terminated.

4 is a flowchart illustrating a call processing procedure of a called party IMS according to an embodiment of the present invention. The process shown in FIG. 4 may correspond to the call processing process in the originating IMS shown in FIG. 3.

When the session request message is normally transmitted to the S-CSCF 116-2 of the called party IMS according to the request of the source terminal (S410), the S-CSCF 116-2 may send a 100 Trying response message (S415). ). Process S410 may correspond to process S350 of FIG. 3.

Thereafter, the S-CSCF 116-2 may retrieve the service profile of the destination terminal 140-2 (S420). According to an embodiment of the present invention, in step S420, the S-CSCF 116-2 extracts subscriber information of the destination terminal 140-2 from the session request message, and exists a service profile corresponding to the extracted subscriber information. You can check whether or not.

If the service profile of the destination terminal 140-2 is found, the S-CSCF 116-2 may perform service triggering (S425). This process may be understood as the process of requesting the media processing server 130 from the S-CSCF 116-1 to provide a specific multimedia service to the source terminal 140-1.

The media processing server 130 may prepare to provide a multimedia service (S430), and transmit a response message indicating that it is ready to provide the multimedia service to the S-CSCF 116-1 (S435).

Thereafter, the S-CSCF 116-2 may transmit a session request message to the P-CSCF 112-2 (S440). The P-CSCF 112-2 may send a 100 Trying response message to the S-CSCF 116-2 (S445), and may transmit a session request message to the destination terminal 140-2 (S450).

If the user of the destination terminal 140-2 accepts the communication with the source terminal, the destination terminal 140-2 may transmit a session response message to the P-CSCF 112-2 (S455).

When the session response message is received from the destination terminal 140-2, the P-CSCF 112-2 may transmit it to the S-CSCF 116-2 (S460), and the S-CSCF 116-2 may This may be transmitted to the S-CSCF (not shown) of the calling IMS (S465). Process S465 of FIG. 4 may correspond to process S355 of FIG. 3.

A call session between the source terminal and the destination terminal 140-2 may be established through steps S410 to S465. When the call session is established, the media processing server 130 forms a media connection with the destination terminal 140-2. It may be (S470). In this case, the media processing server 130 may receive the media stream from the destination terminal 140-2 or transmit the media stream to the destination terminal 140-2.

Although not shown in FIG. 4, the destination terminal 140-2 may also transmit a session end message to the P-CSCF 112-2 like the source terminal 140-1, through which the source terminal 140-2 may be transmitted. The session may be normally terminated through a process similar to the case in which the SEND message is sent.

Through this process, while the media connection is normally maintained, a call session may be abnormally terminated. For example, during a stan-by loading of old software running on the IMS 100 with new software, a call session formed through the old software is the source terminal 140-1 or the destination terminal 140-2. May be terminated without requesting to terminate the session). If the call session ends abnormally, the media connection is also released. Hereinafter, a process of terminating a media connection when a call session ends abnormally will be described with reference to FIGS. 5 to 7.

5 is a flowchart illustrating a call processing process when a call session is abnormally terminated according to an embodiment of the present invention. The illustrated process can be performed at the originating IMS.

After the session is formed through the processes of FIGS. 3 and 4, when it is confirmed that the call session is abnormally terminated (S510), the S-CSCF 116-1 may transmit a session end message to the media processing server 130. There is (S520). The session end message used in step S520 may be a message having the same structure as the session end message used when the source terminal 140-1 requests the session end. In addition, according to an embodiment of the present invention, in step S510, the S-CSCF 116-1 may determine that the call session is abnormally terminated when the call session is terminated without receiving the session termination message. have. Of course, the criteria for determining whether the call session is abnormally terminated are not limited thereto.

The media processing server 130 receiving the session end message from the S-CSCF 116-1 may terminate the media connection (S530). Through this, use of the multimedia service of the source terminal 140-1 and the destination terminal 140-2 may be stopped.

Meanwhile, the media processing server 130 may transmit a session end message to the S-CSCF 116-2 (S540), and the S-CSCF 116-1 may transmit an S-CSCF (not shown) of the destination IMS. This can be transmitted to (S550). Of course, the session termination message does not have to be sent directly from the S-CSCF 116-1 to the S-CSCF of the destination IMS, and the session termination message may be relayed to the S-CSCF of the destination IMS through another device or server. It may be.

Thereafter, if an acknowledgment (hereinafter, referred to as an end response message) to the session end message is received from the called party IMS (S560), the S-CSCF 116-1 may transmit it to the media processing server 130. (S570).

Through this process, as the call session ends, the media connection may be released.

According to an embodiment of the present disclosure, the process S530 of terminating the media connection in FIG. 5 may be performed after the process S570.

6 is a flowchart illustrating a call processing process in a called party IMS according to an embodiment of the present invention. The illustrated flowchart can be seen as a call processing procedure of the called party IMS corresponding to the call processing procedure of the calling party IMS described with reference to FIG. 5.

When the session termination message is transmitted from the calling party IMS to the S-CSCF 116-2 of the called party IMS (S610), the S-CSCF 116-2 may transmit it to the P-CSCF 112-2 ( S620). Process S610 of FIG. 6 may correspond to process S550 of FIG. 5.

The P-CSCF 112-2 may transmit a session end message to the destination terminal 140-2 (S630).

The destination terminal 140-2 receiving the session end message may transmit a termination response message to the P-CSCF 112-2 (S640) and terminate the media connection (S650). In FIG. 6, the process S650 is illustrated as being performed after the process S640, but the present invention is not limited by the temporal and backward relationship between the process S650 and the process S640.

The P-CSCF 112-2 may transmit a termination response message sent from the destination terminal 140-2 to the S-CSCF 116-2 (S660), and the S-CSCF 116-2 again transmits it. It may be transmitted to the calling party IMS (S670). Process 670 of FIG. 6 may correspond to process S560 of FIG. 5.

7 is a flowchart illustrating a call processing procedure of an originating IMS according to another embodiment of the present invention.

After the session is formed through the process of FIGS. 3 and 4, when it is confirmed that the call session is abnormally terminated (S710), the S-CSCF 116-1 sends a session end message to the P-CSCF 112-1. Can be transmitted (S720).

Thereafter, the P-CSCF 112-1 may transmit a session end message to the source terminal 140-1 (S730).

The source terminal 140-1 receiving the session end message may transmit a termination response message to the P-CSCF 112-1 (S740) and terminate the media connection (S750). In FIG. 7, the process S750 is illustrated as being performed after the process S740, but the present invention is not limited by the temporal and backward relationship between the process S750 and the process S740.

On the other hand, the P-CSCF 112-1 may transmit the termination response message transmitted from the source terminal 140-1 to the S-CSCF 116-2 (S760).

5 and 6 illustrate an embodiment that may be performed by the IMS 100 when the S-CSCF 116-1 transmits a session termination message to the media processing server 130. In addition, FIG. 7 may be performed by the IMS 100 when the S-CSCF 116-1 transmits a session termination message to the source terminal 140-1 through the P-CSCF 112-1. An example is shown. However, the present invention is not limited thereto.

For example, as shown in FIG. 8, when it is confirmed that the call session is abnormally terminated (S810), the S-CSCF 116-1 sends a session end message to the media processing server 130 and the P-CSCF 112. -1) may be transmitted to all (S815, S820). Processes S815 and S820 may be performed simultaneously or sequentially, but the present invention is not limited by the order of execution thereof.

Meanwhile, processes S825 to S840 of FIG. 8 may correspond to processes S730 to S760 of FIG. 7, and processes S845 to S865 of FIG. 8 may correspond to processes S530 to S570 of FIG. 5, and thus a detailed description thereof will be omitted. .

Each of the embodiments described above may conform to the 3GPP IMS standard. Accordingly, various call processing procedures specified in the 3GPP IMS standard are applicable for the implementation of the present invention.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. You will understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the call processing system and method of the present invention as described above, the following effects can be produced.

First, when an IMS-based call session is abnormally terminated, there is an advantage that the media connection corresponding to the call session can be normally terminated.

Second, by terminating the media connection corresponding to the abnormally terminated call session, there is an advantage that can prevent the leakage of charges due to the media connection is unjustly maintained.

Claims (11)

In the Internet protocol multimedia subsystem, Establishing a call session; And Outputting a second message requesting termination of a media connection corresponding to the call session when the call session ends when a first message requesting termination of the call session is not received; Call processing method. The method of claim 1, wherein the outputting step, And sending the second message to at least one of a terminal and a media processing server that transmits or receives a media stream over the media connection. The method of claim 2, The media processing server includes at least one of an application server and a multimedia resource device. In the Internet protocol multimedia subsystem, When the call session is terminated without receiving a first message requesting termination of the call session from the terminal, the call session control device managing the call session requests termination of a media connection corresponding to the call session. Outputting a second message; And And terminating the media connection by the media processing server receiving the second message. The method of claim 4, wherein And sending, by the call session control device, the second message to the terminal. The method of claim 4, wherein The media processing server includes at least one of an application server and a multimedia resource device. The method of claim 4, wherein Transmitting, by the media processing server, a third message corresponding to the second message to the call session control device; And And transmitting, by the call session control device, the third message to the counterpart terminal connected to the terminal through the call session. If the call session is terminated without receiving the first message requesting the termination of the call session, and requesting termination of the media connection corresponding to the call session. A call session control device for outputting a second message; And And a media processing server for forming the media connection and terminating the media connection when the second message is output. The method of claim 8, And the call session control device sends the second message to the terminal. The method of claim 8, The media processing server includes at least one of an application server and a multimedia resource device. The method of claim 8, The media processing server transmits a third message corresponding to the second message to the call session controller, and the call session controller transmits the third message to a counterpart terminal connected to the terminal through the call session. , Call processing system.

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