KR20220001150A - Apparatus for connecting session via media gateway for Real-Time Transport Protocol (RTP) communication and method therefor - Google Patents

Abstract

The present invention relates to an apparatus for connecting a session via a media gateway for a real-time transport protocol (RTP) communication to monitor the quality of an RTP and a method thereof. According to an embodiment of the present invention, the apparatus comprises an outgoing access gateway (AGW) and an outgoing proxy server (proxy call state control function, P-CSCF). When receiving a session connection request (INVITE) message requesting a session connection with a called terminal from a calling terminal, the outgoing proxy server includes, in the received session connection request (INVITE) message, connection information for allowing a session connection between the calling terminal and the called terminal to pass through an incoming access gateway (AGW) and address information of the outgoing access gateway (AGW) to transmit the message. When receiving a session connection response (200 OK) message corresponding to the session connection request (INVITE) message, the outgoing proxy server includes the address information of the outgoing access gateway in the received session connection response (200 OK) message to transmit the message to the calling terminal.

Description

Apparatus for connecting session via media gateway for Real-Time Transport Protocol (RTP) communication and method therefor

The present invention relates to a session connection technology, and more particularly, to an apparatus and a method therefor for connecting a session via a media gateway for real-time transport protocol communication.

Session Initiation Protocol (SIP) is a signaling protocol defined by the IETF and is widely used to control multimedia sessions such as voice and video calls. It is an application layer signaling protocol that specifies procedures for identifying each other, finding their location, and creating, deleting, or modifying a multimedia communication session between them. SIP was originally devised in 1996 by Henning Schulzrinne and Mark Handley. The latest version of this specification is RFC 3261 of the IETF Network Working Group. In November 2000, SIP was adopted as the 3GPP signaling protocol and IP Multimedia Subsystem (IMS) architecture for IP-based streaming multimedia services in cellular systems.

Korean Patent Application Laid-Open No. 2012-0018154 published on February 29, 2012 (Title: Single wireless voice call continuity realization method and single wireless voice call continuity system)

An object of the present invention is to provide an apparatus and a method for establishing a session via one of the gateways of the calling party and the called party when connecting a session for real-time transport protocol communication, and a method therefor.

An apparatus for connecting a session according to a preferred embodiment of the present invention for achieving the above object is an outgoing access gateway (AGW) and a session connection request (INVITE) for requesting a session connection from the calling terminal to the called terminal Upon receiving the message, in the received session connection request (INVITE) message, connection information for allowing the session connection between the calling terminal and the called terminal to pass through the outgoing access gateway (AGW) and the address of the outgoing access gateway (AGW) include and transmit information;

Upon receiving a session connection response (200 OK) message corresponding to the session connection request (INVITE) message, the received session connection response (200 OK) message includes the address information of the calling access gateway and transmitted to the calling terminal Includes outgoing proxy server (P-CSCF)

When the device receives the session connection request (INVITE) message and confirms the connection information, the device attaches the session connection request (INVITE) message to the received terminal to establish a session connection with the outgoing access gateway (AGW). When the session connection response (200 OK) message corresponding to the session connection request (INVITE) message is received from the called terminal including the address information of the outgoing access gateway (AGW) and transmitted to the called terminal, the received session The connection response (200 OK) message further includes a destination proxy server (P-CSCF) for transmitting the address information of the destination terminal included.

The address information of the outgoing access gateway (AGW) consists of SDP information of the session connection request (INVITE) message, and the address information of the called terminal consists of SDP information of the session connection response (200 OK) message. do it with

The connection information is characterized in that it consists of SIP header information of the session connection request (INVITE) message.

An apparatus for connecting a session according to a preferred embodiment of the present invention for achieving the above object is an incoming access gateway (AGW) and a session connection request (INVITE) for requesting a session connection from a calling terminal to a called terminal Upon receiving the message, in the received session connection request (INVITE) message, connection information for allowing the session connection between the calling terminal and the called terminal to pass through the incoming access gateway (AGW) and the address of the incoming access gateway (AGW) When the session connection response (200 OK) message corresponding to the session connection request (INVITE) message is received, the received session connection response (200 OK) message includes the address information of the incoming access gateway and a destination proxy server (P-CSCF) that transmits the message to the calling terminal.

When the device receives the session connection request (INVITE) message, and confirms the connection information, the calling terminal attaches the session connection request (INVITE) message to the received session connection request (INVITE) message so that the calling terminal establishes a session connection with the ingress access gateway (AGW). When the session connection response (200 OK) message corresponding to the session connection request (INVITE) message is received from the called terminal including the address information of the calling terminal, the received session connection response 200 OK) further includes an outgoing proxy server (P-CSCF) that transmits by including the address information of the destination access gateway (AGW) in the message.

The address information of the calling terminal is composed of SDP information of the session connection request (INVITE) message, and the address information of the destination access gateway (AGW) is composed of SDP information of the session connection response (200 OK) message. do it with

The connection information is characterized in that it is composed of SIP header information of the session connection request (INVITE) message.

The method for connecting a session according to a preferred embodiment of the present invention for achieving the above object is a session connection request (INVITE) in which an originating proxy server (P-CSCF) requests a session connection from a calling terminal to a called terminal. ) receiving a message, and allowing the originating proxy server (P-CSCF) to connect the session connection between the originating terminal and the destination terminal to the received session connection request (INVITE) message via an originating access gateway (AGW). transmitting connection information and address information of the outgoing access gateway (AGW) including, by the outgoing proxy server (P-CSCF), a session connection response (200 OK) message corresponding to the session connection request (INVITE) message and transmitting, by the originating proxy server (P-CSCF) to the originating terminal, including address information of the originating access gateway in the received session connection response (200 OK) message.

In the method, before the outgoing proxy server (P-CSCF) receives a session connection response (200 OK) message corresponding to the session connection request (INVITE) message, a connection to pass through the outgoing access gateway (AGW) After transmitting the information and the address information of the outgoing access gateway (AGW) inclusive, the called proxy server (P-CSCF) receives the session connection request (INVITE) message and confirms the connection information. The step of including the address information of the outgoing access gateway (AGW) in the received session connection request (INVITE) message so that the terminal establishes a session with the outgoing access gateway (AGW) and transmitting it to the called terminal; When the server (P-CSCF) receives the session connection response (200 OK) message corresponding to the session connection request (INVITE) message from the called terminal, it responds to the received session connection response (200 OK) message of the called terminal. The method further includes transmitting address information.

The address information of the outgoing access gateway (AGW) consists of SDP information of the session connection request (INVITE) message, and the address information of the called terminal consists of SDP information of the session connection response (200 OK) message. do it with

The connection information is characterized in that it is composed of SIP header information of the session connection request (INVITE) message.

The method for connecting a session according to a preferred embodiment of the present invention for achieving the above object is a session connection request (INVITE) in which the called proxy server (P-CSCF) requests a session connection with the called terminal from the calling terminal. ) receiving a message, and the called proxy server (P-CSCF) responds to the received session connection request (INVITE) message so that the session connection between the calling terminal and the called terminal is via the incoming access gateway (AGW). transmitting the connection information and address information of the destination access gateway, and the receiving proxy server (P-CSCF) receiving a session connection response (200 OK) message corresponding to the session connection request (INVITE) message and sending, by the called proxy server (P-CSCF), the address information of the called access gateway in the received session connection response (200 OK) message to the calling terminal.

In the method, before the receiving proxy server (P-CSCF) receives a session connection response (200 OK) message corresponding to the session connection request (INVITE) message, a connection to pass through the incoming access gateway (AGW) After transmitting the information and the destination access gateway address information, the originating proxy server (P-CSCF) receives the session connection request (INVITE) message and confirms the connection information, the calling terminal sends the transmitting the session connection request (INVITE) message including address information of the calling terminal to the called terminal so as to establish a session with an incoming access gateway (AGW); ), when receiving the session connection response (200 OK) message corresponding to the message, the received session connection response (200 OK) message further includes the step of transmitting the included address information of the destination access gateway (AGW).

The address information of the calling terminal is composed of SDP information of the session connection request (INVITE) message, and the address information of the destination access gateway (AGW) is composed of SDP information of the session connection response (200 OK) message. do it with

The connection information is characterized in that it is composed of SIP header information of the session connection request (INVITE) message.

According to the present invention, by allowing RTP communication between the calling and called terminals to go through the calling or called AGW, RTP quality monitoring can be performed, resources are saved, and security that can occur because neither of the calling and called AGWs goes through the AGW. can solve the problem

1 is a diagram for explaining a communication system that provides real-time transport protocol communication according to an embodiment of the present invention.
2 is a flowchart illustrating a method for connecting a session via an originating AGW according to an embodiment of the present invention.
3 is a flowchart illustrating a method for connecting a session via an originating AGW according to another embodiment of the present invention.
4 is a flowchart illustrating a method for connecting a session via an originating AGW according to another embodiment of the present invention.
5 is a flowchart illustrating a method for connecting a session via an originating AGW according to another embodiment of the present invention.
6 is a flowchart illustrating a method for connecting a session via an incoming AGW according to an embodiment of the present invention.
7 is a flowchart illustrating a method for connecting a session via an terminating AGW according to another embodiment of the present invention.
8 is a flowchart illustrating a method for connecting a session via an incoming AGW according to another embodiment of the present invention.
9 is a flowchart illustrating a method for connecting a session via an incoming AGW according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment in which a person of ordinary skill in the art to which the present invention pertains can easily practice the present invention will be described in detail. However, when it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention in describing the operating principle of the preferred embodiment of the present invention in detail, the detailed description thereof will be omitted. This is to more clearly convey the essence of the present invention by omitting unnecessary description. In addition, the present invention can make various changes and can have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description, which is not intended to limit the present invention to specific embodiments, It should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

In addition, when an element is referred to as being “connected” or “connected” to another element, it means that it is logically or physically connected or can be connected. In other words, it should be understood that a component may be directly connected or connected to another component, but another component may exist in between, and may be indirectly connected or connected.

In addition, the terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, terms such as "comprises" or "have" described in this specification are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or the It should be understood that the above does not preclude the possibility of the existence or addition of other features or numbers, steps, operations, components, parts, or combinations thereof.

A method for receiving channel state information and an apparatus supporting the same according to an embodiment of the present invention will now be described in detail with reference to the drawings. In this case, the same reference numerals are used for parts having similar functions and actions throughout the drawings, and overlapping descriptions thereof will be omitted. In addition, in order to avoid obscuring the concept of the present invention, well-known structures and devices may be omitted or shown in block diagram form focusing on core functions of each structure and device.

First, a communication system for providing real-time transport protocol communication by connecting a session via a media gateway according to an embodiment of the present invention will be described. 1 is a diagram for explaining a communication system that provides real-time transport protocol communication according to an embodiment of the present invention. Referring to FIG. 1 , a communication system according to an embodiment of the present invention includes an originating network (ON) and a destination network (IN). The present invention is for communication by connecting a media session between terminals, and the originating network (ON) refers to a side requesting the session connection, and the receiving network (IN) refers to a side accepting the session connection. Accordingly, in the embodiment of the present invention, a device including the term "sender" means an entity belonging to an originating network (ON), and indicates a device including the term "incoming". In addition, in the drawing numbers, when devices of the same type are included in different networks, t is added to the number for the device on the calling side, and r is added to the number for the device on the receiving side to distinguish.

The outgoing network (ON: Outgoing Network) includes an outgoing terminal 10t, an outgoing session border controller (20t: session　border controller (SBC), hereinafter referred to as 'outgoing SBC') and an outgoing service server (300t: Serving Call State Control Function) (S-CSCF), hereinafter referred to as 'outgoing S-CSCF'). In particular, the outgoing SBC 20t is an outgoing proxy server (100t: Proxy Call State Control Function (P-CSCF), hereinafter referred to as 'outgoing P-CSCF') and an outgoing access gateway (200t: Access GateWay, hereinafter, 'outgoing P-CSCF'). AGW').

Incoming network (IN: Incoming Network) includes a called terminal 10r, an incoming session border controller (20r: session 　 border controller (SBC), hereinafter referred to as 'incoming SBC') and an incoming service server (300r: Serving Call State Control Function) (S-CSCF), hereinafter referred to as 'incoming S-CSCF'). In particular, the incoming SBC (20r) is an incoming proxy server (100r: Proxy Call State Control Function (P-CSCF), hereinafter referred to as 'incoming P-CSCF') and an incoming access gateway (200r: Access GateWay, hereinafter, 'incoming P-CSCF') AGW').

In addition, an incoming coloring server 400r is included in the destination network IN for the coloring service, and this incoming coloring server 400r connects a session with the calling terminal 10t to provide a coloring service.

The calling terminal 10t requests a session connection with the called terminal 20r according to SIP (Session Initiation Protocol) for Real-Time Transport Protocol (RTP) communication with the called terminal 10r. A session connection request (INVITE) message (hereinafter referred to as an 'INVITE message') may be transmitted. The session connection request (INVITE) message includes information for identifying the calling terminal 10t, information for identifying the called terminal 20r, and address information (IP version and address) of the calling terminal 10t.

The originating P-CSCF 100t of the originating SBC 20t and the destination P-CSCF 100r of the destination SBC 20r forward the mesh according to the SIP to the originating AGW 200t and the terminating AGW 200t included in the originating SBC 20t. A process for establishing a session via any one of the destination AGWs 200r included in the SBC 20r is performed. At this time, the originating S-CSCF (300t) and the receiving S-CSCF (300r) serve to deliver a message according to the SIP.

When a session via the originating AGW 200t is to be established, the originating P-CSCF 100t provides connection information so that the session connection between the originating terminal 10t and the destination terminal 10r is via the originating AGW 200t, and The address information of the originating AGW 200t is included in the INVITE message and transmitted. This INVITE message is delivered to the destination P-CSCF 100r by the originating S-CSCF 300t and the destination S-CSCF 300r. Then, the called P-CSCF 100r obtains the address information of the calling AGW 200t from the INVITE message, and then provides the address information of the calling AGW 200t to the called terminal 10r. In addition, when the called P-CSCF 100r receives a session connection response (200 OK) message (hereinafter referred to as a '200 OK message') in response to the INVITE message, the address of the called terminal 10r in the 200 OK message information is included and transmitted. This 200 OK message is delivered to the originating P-CSCF 100t by the destination S-CSCF 300r and the originating S-CSCF 300t. Upon receiving the 200 OK message, the originating P-CSCF 100t includes the address information of the originating AGW 200t in the 200 OK message and delivers it to the originating terminal 10t.

In this way, the called terminal 10r and the calling terminal 10t obtained the address information of the calling AGW 200t through the INVITE message and the 200 OK message, respectively, and the calling AGW 200t is the calling P-CSCF 100t. Address information of each of the called terminal 10r and the calling terminal 10t may be recognized through the received INVITE and 200 OK message. Accordingly, a session between the called terminal 10r and the calling AGW 200t may be connected with reference to each other's address information, and a session between the calling AGW 200t and the calling terminal 10t may be connected. Accordingly, a session between the called terminal 10r and the calling terminal 10t is connected via the calling AGW 200t. When such a session is connected, communication between the calling terminal 10t and the called terminal 10r is performed via the calling AGW 200t according to the RTP.

On the other hand, in the case of establishing a session via the called AGW 200r, the calling P-CSCF 100t connects the session connection between the calling terminal 10t and the called terminal 10r via the called AGW 200r. Information and address information of the calling terminal 10t are included in the INVITE message and transmitted.

When a session via the called AGW 200r is to be established, the calling P-CSCF 100t provides connection information for allowing the session connection between the calling terminal 10t and the called terminal 10r to go through the called AGW 200r, and The address information of the calling terminal 10t is included in the INVITE message and transmitted. This INVITE message is delivered to the destination P-CSCF 100r by the originating S-CSCF 300t and the destination S-CSCF 300r. Then, the called P-CSCF 100r obtains the address information of the calling terminal 10t from the INVITE message, and then provides address information of the called AGW 200r to the called terminal 10r. In addition, when the called P-CSCF 100r receives a session connection response (200 OK) message (hereinafter referred to as a '200 OK message') in response to the INVITE message from the called terminal 10r, it receives a 200 OK message The address information of the AGW (200r) is included and transmitted. This 200 OK message is delivered to the originating P-CSCF 100t by the destination S-CSCF 300r and the originating S-CSCF 300t. Upon receiving the 200 OK message, the originating P-CSCF 100t includes the address information of the destination AGW 200r in the 200 OK message and delivers it to the originating terminal 10t.

In this way, the called terminal 10r and the calling terminal 10t obtained the address information of the called AGW 200r through the INVITE message and the 200 OK message, respectively, and the called AGW 200r is the called P-CSCF 100r. Address information of each of the called terminal 10r and the calling terminal 10t may be recognized through the received INVITE and 200 OK message. Therefore, a session between the called terminal 10r and the called AGW 200r is connected with reference to each other's address information, and the session between the called AGW 200r and the calling terminal 10t is connected, so that the called terminal 10r and the calling terminal ( 10t), the session is connected via the terminating AGW 200r. When this session is connected, communication between the calling terminal 10t and the called terminal 10r is performed via the called AGW 200r according to RTP.

Next, a method for connecting a session via an originating AGW according to an embodiment of the present invention will be described. 2 is a flowchart illustrating a method for connecting a session via an originating AGW according to an embodiment of the present invention. In the embodiment of FIG. 2, it is assumed that the media session is connected via the originating AGW 200t, and that both the originating terminal 10t and the destination terminal 10r support IPv4.

Referring to FIG. 2 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S101. The c-field of Session Description Protocol (SDP) information included in the received INVITE message includes the calling terminal IPv4 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for the session connection between the calling terminal 10t and the called terminal 10r via the calling AGW 200t and Address information of the originating AGW 200t is generated, and the generated connection information and address information of the originating AGW 200t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the originating AGW 200t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. This SDP information further includes an outgoing AGW IPv4 address for media session connection used for coloring. More specifically, the SIP header information is “P-Media-path:orig”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv4 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

ⓓ visited-realm 3: Outgoing AGW IPv6 address

In this way, the address information of the originating AGW is transmitted by including both the originating AGW IPv4 address and the originating AGW IPv6 address in the SDP information, so that the destination side can select it.

Next, the originating P-CSCF 100t transmits the INVITE message including the SIP header information and the SDP information generated previously in step S102. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S103. Accordingly, the incoming coloring server 400r can obtain the IPv4 address of the calling AGW from the SDP information included in the INVITE message. Then, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S104 in response to the INVITE message. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the IP version and address of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the outgoing S-CSCF 300t in step S105. Accordingly, the P-CSCF 100t can know the IP version and address of the incoming coloring server 400r through the C-field of the SDP information included in the 183　Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the IP version and address of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Therefore, the originating P-CSCF 100t includes the IPv4 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 183 Session Progress message in step S106 and delivers it to the originating terminal 10t.

Accordingly, in step S107, the session between the incoming coloring server 400r and the calling AGW 200t is connected, and the session between the calling AGW 200t and the calling terminal 10t is connected, and the incoming coloring server 400r and the calling terminal ( 10t) are connected via the originating AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

When the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S108. The INVITE message still includes SIP header information and SDP information such as "P-Media-path:orig" described above.

The called P-CSCF 100r may check the connection information of the INVITE message to confirm that the AGW to be connected is the calling AGW 200t among the calling AGW 200t and the called AGW 200r. That is, the called P-CSCF 100r can know that the called terminal 10r should connect the session with the calling AGW 200t through the SIP header information (ie, "P-Media-path:orig) of the INVITE message. Also, the called P-CSCF 100r can know both the IPv4 address and IPv6 address of the calling AGW 200t through the SDP information of the INVITE message. Accordingly, the called P-CSCF 100r is the called terminal ( 10r) changes the C-field of the SDP information of the INVITE message to the source AGW IPv4 address to match the IP version (IPv4) supported by the destination terminal 10r in step S109 so that the 10r) can establish a session with the source AGW 200t. and transmits it to the called terminal 10r.

Upon receiving the INVITE message, the called terminal 10r connects to the calling AGW 200t and knows that the connection address is the calling AGW IPv4 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S110 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv4 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 Ok message to "C-field: 0.0.0.0". And the called P-CSCF 100r sets visited-realm2 in the SDP information of the 200 Ok message to "visited-realm2: called terminal IPv4 address" so that the called terminal IPv4 address received from the called terminal 10r is delivered. Then, the called P-CSCF (100r) delivers the 200 Ok message to the called S-CSCF (300r) in step S111. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S112.

Upon receiving the 200 OK message, the originating P-CSCF (100t) can know the destination terminal IPv4 address from visited-realm2 among the SDP information of the 200 OK message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the destination terminal IPv4 address. In particular, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Therefore, regardless of the C-Field of the SDP information of the received 200 OK message, the originating P-CSCF 100t transmits the address information of the originating AGW 200t through the 200 OK message, that is, the IP version of the originating terminal 10t ( version) of the originating AGW 200t corresponding to the IPv4 address or IPv6 address of the originating AGW 200t should be transmitted to the originating terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv4 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 200　OK message in step S113 and delivers it to the originating terminal 10t.

Accordingly, in step S114, a session between the called terminal 10r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected, so that the called terminal 10r and the calling terminal 10t are connected. A session between the two is connected via the originating AGW 200t. When the session is connected, communication between the calling terminal 10t and the called terminal 10r is performed according to RTP.

Next, a method for connecting a session via the originating AGW 200t according to another embodiment of the present invention will be described. 3 is a flowchart illustrating a method for connecting a session via an originating AGW according to another embodiment of the present invention. In this embodiment of FIG. 3, it is assumed that the media session is connected via the originating AGW 200t, and that both the calling terminal 10t and the called terminal 10r support IPv6.

Referring to FIG. 3 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S201. The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv6 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for the session connection between the calling terminal 10t and the called terminal 10r via the calling AGW 200t and Address information of the originating AGW 200t is generated, and the generated connection information and address information of the originating AGW 200t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the originating AGW 200t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. This SDP information further includes an outgoing AGW IPv4 address for media session connection used for coloring. More specifically, the SIP header information is “P-Media-path:orig”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv6 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

ⓓ visited-realm 3: Outgoing AGW IPv6 address

In this way, the address information of the originating AGW is transmitted by including both the originating AGW IPv4 address and the originating AGW IPv6 address in the SDP information, so that the destination side can select it.

Next, the originating P-CSCF 100t transmits an INVITE message including the previously generated SIP header information and SDP information in step S202. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S203. Accordingly, the incoming coloring server 400r can obtain the address information of the calling AGW from the SDP information included in the INVITE message. Then, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S204 in response to the INVITE message. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the calling S-CSCF 300t in step S205. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv6 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 183 Session Progress message in step S206 and delivers it to the originating terminal 10t.

Accordingly, in step S207, the session between the incoming coloring server 400r and the calling AGW 200t is connected, and the session between the calling AGW 200t and the calling terminal 10t is connected, and the incoming coloring server 400r and the calling terminal ( 10t) are connected via the originating AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

When coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S208. The INVITE message still includes SIP header information and SDP information such as "P-Media-path:orig" described above.

The called P-CSCF 100r may check the connection information of the INVITE message to confirm that the AGW to be connected is the calling AGW 200t among the calling AGW 200t and the called AGW 200r. That is, the called P-CSCF 100r can know that the called terminal 10r should connect the session with the calling AGW 200t through the SIP header information (ie, "P-Media-path:orig) of the INVITE message. Also, the called P-CSCF 100r can know both the IPv4 address and IPv6 address of the calling AGW 200t through the SDP information of the INVITE message. Accordingly, the called P-CSCF 100r is the called terminal ( Change the C-field information of the SDP information of the INVITE message to the source AGW IPv6 address to match the IP version (IPv6) supported by the destination terminal 10r in step S209 so that 10r) can establish a session with the source AGW 200t. and transmits it to the called terminal 10r.

Upon receiving the INVITE message, the called terminal 10r connects to the calling AGW 200t and knows that the connection address is the calling AGW IPv6 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S210 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv6 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 OK message to "C-field: 0.0.0.0". And the called P-CSCF 100r sets visited-realm3 among the SDP information of the 200 OK message to "visited-realm3: called terminal IPv6 address" so that the called terminal IPv6 address received from the called terminal 10r is delivered. Then, the called P-CSCF 100r delivers the 200 OK message to the called S-CSCF 300r in step S211. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S212.

Upon receiving the 200 OK message, the originating P-CSCF (100t) can know the destination terminal IPv6 address from visited-realm3 among the SDP information of the 200 OK message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the destination terminal IPv6 address. In particular, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Therefore, regardless of the C-Field of the SDP information of the received 200 OK message, the originating P-CSCF 100t transmits the address information of the originating AGW 200t through the 200 OK message, that is, the IP version of the originating terminal 10t ( version) of the originating AGW 200t corresponding to the IPv4 address or IPv6 address of the originating AGW 200t should be transmitted to the originating terminal 10t. Accordingly, the originating P-CSCF 100t includes the originating AGW IPv6 address according to the IP version of the originating terminal 10t in the 200　OK message in step S213 and delivers it to the originating terminal 10t.

Accordingly, in step S214, a session between the called terminal 10r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected, so that the called terminal 10r and the calling terminal 10t are connected. A session between the two is connected via the originating AGW 200t. When the session is connected, communication between the calling terminal 10t and the called terminal 10r is performed according to RTP.

Next, a method for connecting a session via the originating AGW 200t according to another embodiment of the present invention will be described. 4 is a flowchart illustrating a method for connecting a session via an originating AGW according to another embodiment of the present invention. In the embodiment of FIG. 4, it is assumed that the media session is connected via the originating AGW 200t, the originating terminal 10t supports IPv4, and the destination terminal 10r supports IPv6.

Referring to FIG. 4 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S301 . The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv4 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for the session connection between the calling terminal 10t and the called terminal 10r via the calling AGW 200t and Address information of the originating AGW 200t is generated, and the generated connection information and address information of the originating AGW 200t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the originating AGW 200t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. This SDP information further includes an outgoing AGW IPv4 address for media session connection used for coloring. More specifically, the SIP header information is “P-Media-path:orig”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv4 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

ⓓ visited-realm 3: Outgoing AGW IPv6 address

In this way, the address information of the originating AGW is transmitted by including both the originating AGW IPv4 address and the originating AGW IPv6 address in the SDP information, so that the destination side can select it.

Next, the originating P-CSCF 100t transmits the INVITE message including the SIP header information and the SDP information previously generated in step S302. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S303. Accordingly, the incoming coloring server 400r can obtain the address information of the calling AGW from the SDP information included in the INVITE message. Then, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S304 in response to the INVITE message. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the calling S-CSCF 300t in step S305. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv4 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 183 Session Progress message in step S306 and delivers it to the originating terminal 10t.

Accordingly, in step S307, the session between the incoming coloring server 400r and the calling AGW 200t is connected, and the session between the calling AGW 200t and the calling terminal 10t is connected, and the incoming coloring server 400r and the calling terminal ( 10t) are connected via the originating AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

When the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S308. The INVITE message still includes SIP header information and SDP information such as "P-Media-path:orig" described above.

The called P-CSCF 100r may check the connection information of the INVITE message to confirm that the AGW to be connected is the calling AGW 200t among the calling AGW 200t and the called AGW 200r. That is, the called P-CSCF 100r can know that the called terminal 10r should connect the session with the calling AGW 200t through the SIP header information (ie, "P-Media-path:orig) of the INVITE message. Also, the called P-CSCF 100r can know both the IPv4 address and IPv6 address of the calling AGW 200t through the SDP information of the INVITE message. Accordingly, the called P-CSCF 100r is the called terminal ( Change the C-field information of the SDP information of the INVITE message to the source AGW IPv6 address to match the IP version (IPv6) supported by the destination terminal 10r in step S309 so that 10r) can establish a session with the source AGW 200t. and transmits it to the called terminal 10r.

Upon receiving the INVITE message, the called terminal 10r connects to the calling AGW 200t and knows that the connection address is the calling AGW IPv6 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S310 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv6 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 OK message to "C-field: invalid.invalid". And the called P-CSCF 100r sets visited-realm3 among the SDP information of the 200 OK message to "visited-realm3: called terminal IPv6 address" so that the called terminal IPv6 address received from the called terminal 10r is delivered. Then, the called P-CSCF (100r) delivers the 200 OK message to the called S-CSCF (300r) in step S311. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S312.

Upon receiving the 200 OK message, the originating P-CSCF (100t) can know the destination terminal IPv6 address from visited-realm3 among the SDP information of the 200 OK message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the destination terminal IPv6 address. In particular, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Therefore, regardless of the C-Field of the SDP information of the received 200 OK message, the originating P-CSCF 100t transmits the address information of the originating AGW 200t through the 200 OK message, that is, the IP version of the originating terminal 10t ( version) of the originating AGW 200t corresponding to the IPv4 address or IPv6 address of the originating AGW 200t should be transmitted to the originating terminal 10t. Therefore, the originating P-CSCF 100t includes the originating AGW IPv4 address according to the IP version of the originating terminal 10t in the 200　OK message in step S313 and delivers it to the originating terminal 10t.

Accordingly, in step S314, a session between the called terminal 10r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected, so that the called terminal 10r and the calling terminal 10t are connected. A session between the two is connected via the originating AGW 200t. When the session is connected, communication between the calling terminal 10t and the called terminal 10r is performed according to RTP.

Next, a method for connecting a session via the originating AGW 200t according to another embodiment of the present invention will be described. 5 is a flowchart illustrating a method for connecting a session via an originating AGW according to another embodiment of the present invention. 5, it is assumed that the media session is connected via the originating AGW 200t, the originating terminal 10t supports IPv6, and the destination terminal 10r supports IPv4.

Referring to FIG. 5 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S401 . The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv6 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for the session connection between the calling terminal 10t and the called terminal 10r via the calling AGW 200t and Address information of the originating AGW 200t is generated, and the generated connection information and address information of the originating AGW 200t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the originating AGW 200t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. This SDP information further includes an outgoing AGW IPv4 address for media session connection used for coloring. More specifically, the SIP header information is “P-Media-path:orig”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv6 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

ⓓ visited-realm 3: Outgoing AGW IPv6 address

In this way, the address information of the originating AGW is transmitted by including both the originating AGW IPv4 address and the originating AGW IPv6 address in the SDP information, so that the destination side can select it.

Next, the originating P-CSCF 100t transmits an INVITE message including the previously generated SIP header information and SDP information in step S402. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S403. Accordingly, the incoming coloring server 400r can obtain the address information of the calling AGW from the SDP information included in the INVITE message. Then, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S404 in response to the INVITE message. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the calling S-CSCF 300t in step S405. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv6 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 183 Session Progress message in step S306 and delivers it to the originating terminal 10t.

Accordingly, in step S407, a session between the incoming coloring server 400r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected, and the incoming coloring server 400r and the calling terminal ( 10t) are connected via the originating AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

When the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S408. The INVITE message still includes SIP header information and SDP information such as "P-Media-path:orig" described above.

The incoming P-CSCF (100r) checks the connection information ("P-Media-path:orig") of the INVITE message to know that a session connection with the originating AGW 200t will be made among the originating AGW 200t and the destination AGW 200r. can be checked That is, the called P-CSCF 100r can know that the called terminal 10r should connect the session with the calling AGW 200t through the SIP header information (ie, "P-Media-path:orig) of the INVITE message. Also, the called P-CSCF 100r can know both the IPv4 address and IPv6 address of the calling AGW 200t through the SDP information of the INVITE message. Accordingly, the called P-CSCF 100r is the called terminal ( 10r) changes the C-field of the SDP information of the INVITE message to the source AGW IPv4 address to match the IP version (IPv6) supported by the destination terminal 10r in step S409 so that the 10r) can establish a session with the source AGW 200t. and transmits it to the called terminal 10r.

Upon receiving the INVITE message, the called terminal 10r connects to the calling AGW 200t and knows that the connection address is the calling AGW IPv4 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S410 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv4 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 OK message to "C-field: invalid.invalid". And the called P-CSCF 100r sets visited-realm2 of the SDP information of the 200 OK message to "visited-realm2: called terminal IPv4 address" so that the called terminal IPv6 address received from the called terminal 10r is delivered. Then, the called P-CSCF (100r) delivers the 200 OK message to the called S-CSCF (300r) in step S411. This 200 OK message is transferred to the originating P-CSCF 100t through the terminating S-CSCF 300r and the originating S-CSCF 300t in step S412.

Upon receiving the 200 OK message, the originating P-CSCF (100t) can know the destination terminal IPv4 address from visited-realm2 among the SDP information of the 200 OK message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the destination terminal IPv4 address. In particular, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Therefore, regardless of the C-Field of the SDP information of the received 200 OK message, the originating P-CSCF 100t transmits the address information of the originating AGW 200t through the 200 OK message, that is, the IP version of the originating terminal 10t ( version) of the originating AGW 200t corresponding to the IPv4 address or IPv6 address of the originating AGW 200t should be transmitted to the originating terminal 10t. Accordingly, the originating P-CSCF 100t includes the originating AGW IPv6 address according to the IP version of the originating terminal 10t in the 200　OK message in step S413 and delivers it to the originating terminal 10t. Then, in step S414, a session between the called terminal 10r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected. Accordingly, a session between the called terminal 10r and the calling terminal 10t is connected via the calling AGW 200t. When such a session is connected, communication between the calling terminal 10t and the called terminal 10r is performed according to RTP.

Incoming AGW Via Operation Description

(1) Next, a method for connecting a session via the destination AGW 200r according to an embodiment of the present invention will be described. 6 is a flowchart illustrating a method for connecting a session via an incoming AGW according to an embodiment of the present invention. 6, it is assumed that the media session is connected via the called AGW 200r, and that both the calling terminal 10t and the called terminal 10r support IPv4.

Referring to FIG. 6 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S501. The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv4 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for allowing the session connection between the calling terminal 10t and the called terminal 10r to pass through the called AGW 200r, and Address information of the calling terminal 10t is generated, and the generated connection information and address information of the calling terminal 10t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the calling terminal 10t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. This SDP information further includes an outgoing AGW IPv4 address for media session connection used for coloring. More specifically, the SIP header information is “P-Media-path:orig”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv4 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

Next, the originating P-CSCF 100t transmits the INVITE message including the SIP header information and the SDP information previously generated in step S502. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S503. Accordingly, the incoming coloring server 400r can obtain the IPv4 address of the calling AGW from the SDP information included in the INVITE message. Then, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S504 in response to the INVITE message. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the calling S-CSCF 300t in step S505. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv4 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 183　Session Progress message in step S506 and delivers it to the originating terminal 10t. Then, in step S507, a session between the incoming coloring server 400r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected. Accordingly, a session between the incoming coloring server 400r and the calling terminal 10t is connected via the calling AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

When the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S508. The INVITE message still includes SIP header information and SDP information such as "P-Media-path:term" previously included (S502).

The terminating P-CSCF 100r confirms that the AGW to be connected is the terminating AGW 200r among the originating AGW 200t and the terminating AGW 200r through the SIP header information (ie, "P-Media-path:term) of the INVITE message. Accordingly, the called P-CSCF 100r sends the IP version (IPv4) supported by the called terminal 10r in step S509 so that the called terminal 10r can perform RTP communication through the called AGW 200r. The C-field information included in the SDP of the INVITE message is changed to the destination AGW IPv4 address and delivered to the destination terminal 10r.

Upon receiving the INVITE message, the called terminal 10r knows that a session connection is established with the called AGW 200t, and the connection address is the called AGW IPv4 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S510 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv4 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 Ok message to "C-field: 0.0.0.0". And the called P-CSCF (100r) can know the IP version (IPv4) supported by the calling terminal (10t) through the SDP information (ⓑ visited-realm 1: calling terminal IPv4 address) of the INVITE message received earlier (S508). have. Accordingly, the called P-CSCF 100r sets the visited-realm1 among the SDP information of the 200 OK message to "visited-realm1: called AGW IPv4 address" according to the IP version (IPv4) supported by the calling terminal 10t. . Then, the called P-CSCF (100r) delivers the 200 Ok message to the called S-CSCF (300r) in step S511. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S512.

Upon receiving the 200 OK message, the originating P-CSCF (100t) can know the destination AGW IPv4 address from visited-realm1 among the SDP information of the 200 OK message. Accordingly, the originating P-CSCF 100t includes the IPv4 address of the destination AGW in the 200　OK message in step S513 so that the originating terminal 10t can connect with the destination AGW 200r and delivers it to the originating terminal 10t. Then, in step S514, a session between the called terminal 10r and the called AGW 200r is connected, and a session between the called AGW 200r and the calling terminal 10t is connected, so that the called terminal 10r and the calling terminal 10t are connected. The session is connected via the terminating AGW 200r. When this session is connected, communication between the calling terminal 10t and the called terminal 10r is performed via the called AGW 200r according to RTP.

(2) Next, a method for connecting a session via the destination AGW 200r according to another embodiment of the present invention will be described. 7 is a flowchart illustrating a method for connecting a session via an terminating AGW according to another embodiment of the present invention. In this embodiment of FIG. 7, it is assumed that the media session is connected via the destination AGW 200r, and both the calling terminal 10t and the called terminal 10r support IPv6.

Referring to FIG. 7 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S601 . The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv6 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for allowing the session connection between the calling terminal 10t and the called terminal 10r to pass through the called AGW 200r, and Address information of the calling terminal 10t is generated, and the generated connection information and address information of the calling terminal 10t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the calling terminal 10t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. More specifically, the SIP header information is “P-Media-path:term”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv6 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

Next, the originating P-CSCF 100t transmits an INVITE message including the previously generated SIP header information and SDP information in step S602. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S603. Accordingly, the incoming coloring server 400r can obtain the IPv4 address of the calling AGW from the SDP information included in the INVITE message. Then, in response to the INVITE message, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S604. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the outgoing S-CSCF 300t in step S605. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv6 address of the originating AGW 200t according to the IP version of the originating terminal 10t in the 183 Session Progress message in step S606 and delivers it to the originating terminal 10t. Then, in step S607 , a session between the incoming coloring server 400r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected. Accordingly, a session between the incoming coloring server 400r and the calling terminal 10t is connected via the calling AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t. After the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S608. The INVITE message still includes SIP header information and SDP information such as "P-Media-path: term" previously included (S602).

The terminating P-CSCF 100r confirms that the AGW to be connected is the terminating AGW 200r among the originating AGW 200t and the terminating AGW 200r through the SIP header information (ie, "P-Media-path: term) of the INVITE message. Accordingly, the called P-CSCF 100r sends the IP version (IPv6) supported by the called terminal 10r in step S609 so that the called terminal 10r can perform RTP communication through the called AGW 200r. The C-field information included in the SDP of the INVITE message is changed to the destination AGW IPv6 address and delivered to the destination terminal 10r.

Upon receiving the INVITE message, the called terminal 10r knows that a session connection is established with the called AGW 200t, and the connection address is the called AGW IPv4 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S610 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv6 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 Ok message to "C-field: 0.0.0.0". And the called P-CSCF (100r) can know the IP version (IPv6) supported by the calling terminal (10t) through the SDP information (ⓑ visited-realm 1: calling terminal IPv6 address) of the INVITE message received earlier (S608). have. Accordingly, the called P-CSCF 100r sets visited-realm1 among the SDP information of the 200 OK message to "visited-realm1: called AGW IPv6 address" according to the IP version supported by the calling terminal 10t. Then, the called P-CSCF (100r) delivers the 200 Ok message to the called S-CSCF (300r) in step S611. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S612.

Upon receiving the 200 OK message, the originating P-CSCF 100t can know the destination AGW IPv6 address from visited-realm1 among the SDP information of the 200 OK message. Accordingly, the originating P-CSCF 100t includes the IPv6 address of the destination AGW in the 200　OK message in step S613 so that the originating terminal 10t can connect with the destination AGW 200r and delivers it to the originating terminal 10t. Then, in step S614, a session between the called terminal 10r and the called AGW 200r is connected, and a session between the called AGW 200r and the calling terminal 10t is connected, so that the called terminal 10r and the calling terminal 10t are connected. The session is connected via the terminating AGW 200r. When this session is connected, communication between the calling terminal 10t and the called terminal 10r is performed via the called AGW 200r according to RTP.

(3) Next, a method for connecting a session via the destination AGW 200r according to another embodiment of the present invention will be described. 8 is a flowchart illustrating a method for connecting a session via an incoming AGW according to another embodiment of the present invention. 8, it is assumed that the media session is connected via the destination AGW 200r, the originating terminal 10t supports IPv4, and the destination terminal 10r supports IPv6.

Referring to FIG. 8 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S701. The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv4 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for allowing the session connection between the calling terminal 10t and the called terminal 10r to pass through the called AGW 200r, and Address information of the calling terminal 10t is generated, and the generated connection information and address information of the calling terminal 10t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the calling terminal 10t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. More specifically, the SIP header information is “P-Media-path: term”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv4 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

Next, the originating P-CSCF 100t transmits an INVITE message including the previously generated SIP header information and SDP information in step S702. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S703. Accordingly, the incoming coloring server 400r can obtain the IPv4 address of the calling AGW from the SDP information included in the INVITE message. Then, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S704 in response to the INVITE message. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the outgoing S-CSCF 300t in step S705. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Accordingly, the originating P-CSCF 100t includes the IPv4 address of the originating AGW 200t according to the IP version (IPv4) of the originating terminal 10t in the 183 Session Progress message in step S706 and delivers it to the originating terminal 10t. Then, in step S707 , a session between the incoming coloring server 400r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected. Accordingly, a session between the incoming coloring server 400r and the calling terminal 10t is connected via the calling AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

After the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S708. The INVITE message still includes SIP header information and SDP information such as "P-Media-path: term" previously included (S702).

The terminating P-CSCF (100r) confirms that the AGW to be connected is the terminating AGW (200r) among the originating AGW (200t) and the terminating AGW (200r) through the SIP header information (ie, "P-Media-path: term) of the INVITE message. Accordingly, the called P-CSCF 100r sends the IP version (IPv6) supported by the called terminal 10r in step S709 so that the called terminal 10r can perform RTP communication through the called AGW 200r. The C-field information included in the SDP of the INVITE message is changed to the destination AGW IPv6 address and delivered to the destination terminal 10r.

Upon receiving the INVITE message, the called terminal 10r knows that the session connection is established with the called AGW 200t, and the connection address is the called AGW IPv6 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S710 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv6 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 Ok message as "C-field" because the IP versions of both the calling terminal 10t and the called terminal 10r are different. :invalid.invalid". And the called P-CSCF (100r) can know the IP version (IPv4) supported by the calling terminal (10t) through the SDP information (ⓑ visited-realm 1: calling terminal IPv4 address) of the INVITE message received earlier (S708). have. Accordingly, the called P-CSCF 100r sets visited-realm1 among the SDP information of the 200 OK message to "visited-realm1: called AGW IPv4 address" according to the IP version supported by the calling terminal 10t. Then, the called P-CSCF (100r) delivers the 200 Ok message to the called S-CSCF (300r) in step S711. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S712.

Upon receiving the 200 OK message, the originating P-CSCF (100t) can know the destination AGW IPv4 address from visited-realm1 among the SDP information of the 200 OK message. Accordingly, the originating P-CSCF 100t includes the IPv4 address of the destination AGW in the 200　OK message in step S713 so that the originating terminal 10t can connect with the destination AGW 200r and delivers it to the originating terminal 10t. Then, in step S714, the session between the called terminal 10r and the called AGW 200r is connected, and the session between the called AGW 200r and the calling terminal 10t is connected. Accordingly, a session between the called terminal 10r and the calling terminal 10t is connected via the called AGW 200r. When this session is connected, communication between the calling terminal 10t and the called terminal 10r is performed via the called AGW 200r according to RTP.

(4) Next, a method for connecting a session via the destination AGW 200r according to another embodiment of the present invention will be described. 9 is a flowchart illustrating a method for connecting a session via an incoming AGW according to another embodiment of the present invention. 9, it is assumed that the media session is connected via the called AGW 200r, the calling terminal 10t supports IPv6, and the called terminal 10r supports IPv4.

Referring to FIG. 9 , the originating P-CSCF 100t may receive a session connection request (INVITE) message according to the Session Initiation Protocol (SIP) from the originating terminal 10t in step S801. The c-field of the SDP information included in the received INVITE message includes the calling terminal IPv6 address. In this way, upon receiving the INVITE message from the calling terminal 10t, the calling P-CSCF 100t provides connection information for allowing the session connection between the calling terminal 10t and the called terminal 10r to pass through the called AGW 200r, and Address information of the calling terminal 10t is generated, and the generated connection information and address information of the calling terminal 10t are included in the received INVITE message. Here, the connection information is composed of SIP header information of the session connection request (INVITE) message, and the address information of the calling terminal 10t is composed of SDP (Session Description Protocol) information included in the session connection request (INVITE) message. More specifically, the SIP header information is “P-Media-path: term”, and the Session Description Protocol (SDP) information includes the following fields.

ⓐ c-field: Outgoing AGW IPv4 address

ⓑ visited-realm 1: IPv6 address of the calling terminal

ⓒ visited-realm 2: Outgoing AGW IPv4 address

Next, the originating P-CSCF 100t transmits the INVITE message including the SIP header information and the SDP information previously generated in step S802. This INVITE message is transmitted to the incoming coloring server 400r through the outgoing S-CSCF 300t and the incoming S-CSCF 300r in step S803. Accordingly, the incoming coloring server 400r can obtain the IPv4 address of the calling AGW from the SDP information included in the INVITE message. Then, in response to the INVITE message, the incoming coloring server 400r transmits a session continuation response (183 Session Progress) message in step S804. At this time, the 183　Session Progress message includes SDP information, and the incoming coloring server 400r includes the address information (IP version and address) of the incoming coloring server 400r in the C-field of the SDP information and delivers it. This 183　Session Progress message is transmitted to the calling P-CSCF 100t through the called S-CSCF 300r and the outgoing S-CSCF 300t in step S805. Accordingly, the P-CSCF 100t can know the address information (IP version and address) of the incoming coloring server 400r through the C-field of the SDP information included in the 183 Session Progress message. Accordingly, the originating AGW 200t in the same originating SBC 20t can also know the address information of the destination coloring server 400r.

Regardless of the IP version supported by the coloring server 400r, all RTP traffic of the originating terminal 10t must pass through the originating AGW 200t. Accordingly, the originating P-CSCF 100t transmits the originating AGW corresponding to the IP version of the originating terminal 10t through the 183　Session Progress message regardless of the C-Field information included in the received 183　Session Progress message. The IPv4 address or IPv6 address of 200t should be delivered to the calling terminal 10t. Therefore, the originating P-CSCF 100t includes the IPv6 address of the originating AGW 200t in accordance with the IP version (IPv6) of the originating terminal 10t in the 183 Session Progress message in step S806 and delivers it to the originating terminal 10t. Then, in step S807, a session between the incoming coloring server 400r and the calling AGW 200t is connected, and a session between the calling AGW 200t and the calling terminal 10t is connected. Accordingly, a session between the incoming coloring server 400r and the calling terminal 10t is connected via the calling AGW 200t. When such a session is connected, a color-ring-back-tone transmitted by the incoming coloring server 400r according to the RTP is transmitted to the calling terminal 10t via the calling AGW 200t.

On the other hand, after the coloring is finished, the INVITE message is delivered to the called P-CSCF 100r through the calling S-CSCF 300t and the called S-CSCF 300r in step S808. The INVITE message still includes SIP header information and SDP information such as "P-Media-path: term" previously included (S802).

The terminating P-CSCF 100r confirms that the AGW to be connected is the terminating AGW 200r among the originating AGW 200t and the terminating AGW 200r through the SIP header information (ie, "P-Media-path: term) of the INVITE message. Accordingly, the called P-CSCF 100r sends the IP version (IPv4) supported by the called terminal 10r in step S809 so that the called terminal 10r can perform RTP communication through the called AGW 200r. The C-field information included in the SDP of the INVITE message is changed to the destination AGW IPv4 address and delivered to the destination terminal 10r.

Upon receiving the INVITE message, the called terminal 10r knows that a session connection is established with the called AGW 200t, and the connection address is the called AGW IPv4 address. Then, the called terminal 10r transmits a session connection response (200 OK) message to the called P-CSCF 100r in step S710 in response to the received INVITE message. In this case, the called terminal 10r includes its own IPv4 address in the 200 OK message for RTP communication and transmits it.

Upon receiving the 200 OK message, the called P-CSCF 100r sets the C-field of the SDP information of the 200 OK message as "C-field" because the IP versions of both the calling terminal 10t and the called terminal 10r are different. :invalid.invalid". And the called P-CSCF (100r) can know the IP version (IPv6) supported by the calling terminal (10t) through the SDP information (ⓑ visited-realm 1: calling terminal IPv6 address) of the INVITE message received earlier (S808). have. Accordingly, the called P-CSCF 100r sets visited-realm1 among the SDP information of the 200 OK message to "visited-realm1: called AGW IPv6 address" according to the IP version supported by the calling terminal 10t. Then, the called P-CSCF (100r) delivers the 200 OK message to the called S-CSCF (300r) in step S811. This 200 OK message is delivered to the originating P-CSCF (100t) through the terminating S-CSCF (300r) and the originating S-CSCF (300t) in step S812.

Upon receiving the 200 OK message, the originating P-CSCF 100t can know the destination AGW IPv6 address from visited-realm1 among the SDP information of the 200 OK message. Accordingly, the originating P-CSCF 100t includes the IPv6 address of the destination AGW in the 200　OK message in step S813 so that the originating terminal 10t can connect with the destination AGW 200r and delivers it to the originating terminal 10t. Then, in step S814, the session between the called terminal 10r and the called AGW 200r is connected, and the session between the called AGW 200r and the calling terminal 10t is connected. Accordingly, a session between the called terminal 10r and the calling terminal 10t is connected via the called AGW 200r. When this session is connected, communication between the calling terminal 10t and the called terminal 10r is performed via the called AGW 200r according to RTP.

Meanwhile, the method according to an embodiment of the present invention may be provided in the form of a computer-readable medium suitable for storing computer program instructions and data. Such a computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination, and includes all types of recording devices in which data readable by a computer system is stored. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, compact disk read only memory (CD-ROM), and optical recording media such as DVD (Digital Video Disk). Stores program instructions such as Magneto-Optical Media, ROM (Read Only Memory), RAM (Random Access Memory), Flash memory, etc. and hardware devices specially configured to perform In addition, the computer-readable recording medium is distributed in a computer system connected through a network, so that the computer-readable code can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the technical field to which the present invention pertains.

Although the above has been described and illustrated in relation to the preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as such, and without departing from the scope of the technical idea. It will be apparent to those skilled in the art that many changes and modifications to the present invention are possible. Accordingly, all such suitable alterations and modifications and equivalents are to be considered as falling within the scope of the present invention.

According to an apparatus for connecting a session via a media gateway for real-time transport protocol communication and a method therefor according to the present invention, a session via any one of the gateways of the calling party and the called party for real-time transport protocol communication can be established. Accordingly, RTP quality monitoring can be performed, resources are saved, and security problems that may occur due to not passing through both the originating and terminating AGWs can be solved. The present invention has industrial applicability because it has sufficient potential for marketing or business, as well as to the extent that it can be clearly implemented in reality.

10t, 10r: terminal
20t, 20r: session border controller (SBC)
100t, 100r: Proxy Server (Proxy Call State Control Function: P-CSCF)
200t, 200r: Access GateWay (AGW)
300t, 300r: Service Server (Serving Call State Control Function: S-CSCF)
400r: coloring server

Claims (16)

outgoing access gateway (AGW);
When receiving a session connection request (INVITE) message requesting a session connection with the called terminal from the calling terminal, the session connection request message between the calling terminal and the called terminal passes through the calling access gateway The connection information and the address information of the outgoing access gateway are included and transmitted,
When receiving a session connection response (200 OK) message corresponding to the session connection request message, the received session connection response message includes the address information of the outgoing access gateway and transmits it to the calling terminal
Outgoing proxy server (P-CSCF); including
A device for connecting sessions. According to claim 1,
receiving the session connection request message;
If you check the above connection information,
The called terminal includes the address information of the outgoing access gateway in the received session connection request message to connect the session with the outgoing access gateway and transmits it to the called terminal,
When receiving the session connection response message corresponding to the session connection request message from the called terminal, the received session connection response message includes the address information of the called terminal and transmits it
incoming proxy server;
characterized in that it further comprises
A device for connecting sessions. 3. The method of claim 2,
The address information of the outgoing access gateway is
It consists of SDP (Session Description Protocol) information of the session connection request message,
The address information of the called terminal is
characterized in that it is composed of SDP information of the session connection response message
A device for connecting sessions. According to claim 1,
The connection information is
characterized in that it is composed of SIP (Session Initiation Protocol) header information of the session connection request message
A device for connecting sessions. Incoming Access Gateway (AGW);
When receiving a session connection request (INVITE) message requesting a session connection with the called terminal from the calling terminal,
Transmitting the received session connection request message by including connection information for allowing the session connection between the calling terminal and the called terminal to pass through the called access gateway and address information of the called access gateway;
Upon receiving a session connection response (200 OK) message corresponding to the session connection request message, the received session connection response message includes the address information of the destination access gateway and transmitted to the calling terminal
Incoming Proxy Server (P-CSCF); including
A device for connecting sessions. 6. The method of claim 5,
receiving the session connection request message;
If you check the above connection information,
and transmits to the called terminal by including the address information of the calling terminal in the received session connection request message so that the calling terminal establishes a session with the called access gateway;
When receiving the session connection response message corresponding to the session connection request message from the called terminal, the received session connection response message includes the address information of the called access gateway and transmits it
outgoing proxy server;
characterized in that it further comprises
A device for connecting sessions. 7. The method of claim 6,
The address information of the calling terminal is
It consists of SDP (Session Description Protocol) information of the session connection request message,
The address information of the incoming access gateway is
characterized in that it is composed of SDP information of the session connection response message
A device for connecting sessions. 6. The method of claim 5,
The connection information is
characterized in that it is composed of SIP (Session Initiation Protocol) header information of the session connection request message
A device for connecting sessions. receiving, by the calling proxy server (P-CSCF), a session connection request (INVITE) message requesting a session connection with the called terminal from the calling terminal;
transmitting, by the outgoing proxy server, including connection information for allowing the session connection between the calling terminal and the called terminal to pass through an outgoing access gateway and address information of the outgoing access gateway in the received session connection request message;
receiving, by the originating proxy server, a session connection response (200 OK) message corresponding to the session connection request message; and
transmitting, by the outgoing proxy server, address information of the outgoing access gateway in the received session connection response message to the calling terminal;
characterized in that it comprises
A method for connecting sessions. 10. The method of claim 9,
Before the sending proxy server receiving a session connection response message corresponding to the session connection request message,
After transmitting the connection information to pass through the outgoing access gateway and the address information of the outgoing access gateway,
When the called proxy server receives the session connection request message and confirms the connection information, the address of the outgoing access gateway (AGW) in the received session connection request message so that the called terminal establishes a session with the outgoing access gateway transmitting the included information to the called terminal; and
when the called proxy server receives the session connection response message corresponding to the session connection request message from the called terminal, transmitting the session connection response message including address information of the called terminal;
characterized in that it further comprises
A method for connecting sessions. 11. The method of claim 10,
The address information of the outgoing access gateway is
It consists of SDP (Session Description Protocol) information of the session connection request message,
The address information of the called terminal is
Consisting of SDP information of the session connection response message
characterized by
A method for connecting sessions. 10. The method of claim 9,
The connection information is
characterized in that it is composed of SIP (Session Initiation Protocol) header information of the session connection request message
A method for connecting sessions. receiving, by the called proxy server (P-CSCF), a session connection request (INVITE) message requesting a session connection with the called terminal from the calling terminal;
The destination proxy server transmits the received session connection request message by including connection information for allowing the session connection between the originating terminal and the destination terminal to pass through the destination access gateway (AGW) and address information of the destination access gateway step;
receiving, by the called proxy server, a session connection response (200 OK) message corresponding to the session connection request message; and
transmitting, by the called proxy server, address information of the called access gateway in the received session connection response message to the calling terminal;
characterized in that it comprises
A method for connecting sessions. 14. The method of claim 13,
Before the receiving proxy server receives a session connection response message corresponding to the session connection request message,
After transmitting the connection information to pass through the incoming access gateway and the address information of the incoming access gateway,
When the calling proxy server receives the session connection request message and confirms the connection information, the calling terminal includes the address information of the calling terminal in the received session connection request message so that the calling terminal establishes a session with the incoming access gateway. transmitting to the called terminal; and
transmitting, when receiving the session connection response message corresponding to the session connection request message from the called terminal, including address information of the called access gateway in the received session connection response message;
characterized in that it further comprises
A method for connecting sessions. 15. The method of claim 14,
The address information of the calling terminal is
It consists of SDP (Session Description Protocol) information of the session connection request message,
The address information of the incoming access gateway is
characterized in that it is composed of SDP information of the session connection response message
A method for connecting sessions. 14. The method of claim 13,
The connection information is
characterized in that it is composed of SIP (Session Initiation Protocol) header information of the session connection request message
A method for connecting sessions.

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