KR20030014815A - Foreign Agent for Supporting IP mobility in UMTS and Method for IP mobility by using it - Google Patents

Abstract

PURPOSE: An FA(Foreign Agent) device for supporting a mobile IP(Internet Protocol) service in an asynchronous mobile communication system and a mobile IP service method using the same are provided to support the mobile IP service about an asynchronous mobile communication network and support several new standards. CONSTITUTION: A mobile IP service registration unit(206) performs a signal process for a mobile IP. A GGSN(Gateway GPRS(General Packet Radio Service) Support Node) interface unit(201) is connected to the mobile IP service registration unit(206) and is interfaced to an asynchronous mobile communication network. A diameter protocol processing unit(204) transmits and receives data with an authentication and billing server(132) of a mobile IP network by an authentication protocol. An authentication unit(202) connects to the mobile IP service registration unit(206) and the diameter protocol processing unit(204), and performs an authentication function of an FA unit by the control of the mobile IP service registration unit(206). A billing processing unit(203) connects to the mobile IP service registration unit(206) and the diameter protocol processing unit(204), gathers billing information about a packet which passes an FA(131) by the control of the mobile IP service registration unit(206), and transmits gathered billing information. A packet routing and tunneling control unit(205) designates a routing table about a mobile node(11) and performs a setup/release function of a tunnel by the control of the mobile IP service registration unit(206).

Description

External agent device supporting mobile IP service in asynchronous mobile communication system and mobile IP service method using same {Foreign Agent for Supporting IP mobility in UMTS and Method for IP mobility by using it}

The present invention relates to an external agent device supporting a mobile IP service in an asynchronous mobile communication system, a mobile IP service method using the same, and a computer-readable recording medium having recorded thereon a program for realizing the method.

The existing external agent viewed the access network as wired / wireless LAN or synchronous IMT-2000. The external agent for providing mobile IP service in the wired / wireless LAN could play its role in the form of extending the mobile IP protocol to the existing router related protocol by using the access protocol in the second layer. In addition, in the synchronous IMT-2000, the external agent and the synchronous IMT-2000 can be connected by using an interface or a protocol of the PPP layer used for providing a conventional wireless data service.

However, external agents capable of supporting mobile IP services for GPRS networks, which are asynchronous mobile communication systems that are being standardized in Europe, have not yet been proposed.

In addition, many new specifications have been proposed, compared to the current standardized mobile IP protocol, and there are no external agents that can support these new specifications.

The present invention has been proposed to solve the above problems, and supports mobile IP service for asynchronous mobile communication network, and supports mobile IP service in asynchronous mobile communication system that can support various new standards. An object of the present invention is to provide an external agent device, a mobile IP service method using the same, and a computer-readable recording medium having recorded thereon a program for realizing the method.

1 is a diagram illustrating an embodiment of an asynchronous IMT-2000 system to which the present invention is applied.

2 is a diagram illustrating an embodiment of an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention.

3 is a diagram illustrating an embodiment of a signaling protocol stack used for an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention;

4 is a structural diagram of an embodiment of a traffic stack used for an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention;

5A through 5B are flowcharts illustrating an embodiment of operation for a mobile IP service in an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention.

* Explanation of symbols for the main parts of the drawings

201: GGSN matching unit 202: authentication unit

203: billing processing unit 204: diamond protocol processing unit

205: packet routing and tunneling control unit

206: Mobile IP service register

The present invention for achieving the above object, in the external agent device used in the asynchronous mobile communication system, to control the internal means of the external agent device, performs a signal processing for the mobile IP (IP: Internet Protocol) Mobile IP service registration means for performing; Network matching means connected with the mobile IP service registration means to match an asynchronous mobile communication network; Authentication protocol processing means for allowing the external agent device to transmit and receive an authentication and billing server of the mobile IP network using an authentication protocol; Authentication means connected to said mobile IP service registration means and said authentication protocol processing means, for performing an authentication function of an external agent unit under control of said mobile IP service registration means; Connected to the mobile IP service registration means and the authentication protocol processing means, collects charging information for a packet passing through the foreign agent under the control of the mobile IP service registration means, and charges for transmitting the collected charging information; Processing means; And a packet routing and tunneling control means for designating a routing table for the mobile node under the control of the mobile IP service registration means, and performing a tunnel setting / release function.

On the other hand, the present invention, in the mobile IP service method using an external agent device used in the asynchronous mobile communication system, the external agent to the mobile IP service start request signal of the mobile node received from the asynchronous mobile communication network through the network matching unit; Thereby, the first step of performing the mobile IP service registration of the mobile node to the home agent; A second step of transmitting a signal through the network matching unit to notify the mobile node of the failed registration of the mobile IP through the asynchronous mobile communication network when the registration of the mobile IP service of the first step fails; And a third step of enabling the connection of the mobile node to the counterpart node through the routing and tunneling registration when the registration of the mobile IP service of the first step is successful.

On the other hand, the present invention, the external agent device used in an asynchronous mobile communication system having a processor, by the mobile IP service start request signal of the mobile node received by the external agent from the asynchronous mobile communication network through a network matching unit, A first function of performing mobile IP service registration of a mobile node with a home agent; A second function of transmitting a signal through a network matching unit to notify a mobile node of a failed registration of a mobile IP through an asynchronous mobile communication network when registration of the mobile IP service by the first function fails; And when the mobile IP service registration by the first function is successful, through a routing and tunneling registration, a program for realizing a third function for enabling the mobile node to connect to a counterpart node. Provide a record carrier.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the present invention will be described using a GPRS (General Packet Radio Service) network as an example of an asynchronous mobile communication network.

1 is a diagram illustrating an embodiment of an asynchronous IMT-2000 system to which the present invention is applied.

As shown in FIG. 1, the asynchronous IMT-2000 system to which the present invention is applied provides a mobile IP for the GPRS network 12 and the GPRS network 12 that are connected to the mobile node 11 to support wireless communication. Mobile IP network 13, public Internet 14 for providing data services, and public telephone network 15 for circuit-based telephone services.

First, the GPRS network 12 matches with the public Internet 14 or the Internet service provider, and combines with the external agent 131 of the mobile IP network 13 to support the mobile IP service. Gateway GPRS Support Node (GGSN) 123, which acts as a gateway, performs the function of the end of GRS (GPRS Tunneling Protocol), which is a tunneling protocol of GGSN 123 and GPRS network 12, and all users in the service area. And a Serving GPRS Support Node (SGSN) 122 for providing packet services to the RNC and a Radio Network Controller (RNC) 121 for supporting circuit-type telephony and packet data services.

And, the mobile IP network 13 is present in the home network of the mobile node 11, the home agent (HA: Home agent) (133), which delivers the mobile node received datagram, preserves the location information of the mobile node, mobile For a foreign agent (FA) 131 and a mobile node 11, which exist in the mobile network of the node 11 and re-route the datagram sent from the home agent 133 to the mobile node 11, Authentication, Authorization and Accounting Server (AAA) server 132 for authentication.

Looking at the overall operation, the GPRS network 12 is a network accessed by a mobile node (MN) 11, the mobile node 11 is a radio network controller in the GPRS network 12 (Radio Network Controller) : RNC) 121 is wirelessly connected.

In this case, the wireless data network controller 121 may support a circuit type telephone service and a packet data service, and are connected to the SGSN 122 to support a packet data service, and MSC / VLR (Mobile Switching Service Center / Visor Location Register) (101) supports the circuit method.

In addition, the SGSN 122 provides a session management and mobility management function for the subscriber to support the packet data service of the GPRS network subscriber, MSC / VLR 101, HLR / AC (Home Location) to find out information about the subscriber Ragistration / Authorization Center) 102. In addition, the MSC / VLR 101 is connected to the public telephone network 15 for circuit telephone service.

In addition, the GGSN 104 performs a gateway function of the GPRS network, which is an asynchronous mobile communication network, matches with the public Internet 14 or an Internet service provider, and supports an external agent of the mobile IP network 13 to support mobile IP services. 131).

The mobile IP network 13 includes an external agent 131, an authentication and billing server 132, and a home agent 133, and in particular is coupled to the GPRS network 12 by the external agent 131. All nodes 131, 132, and 133 of the mobile IP network 13 may transmit control packets and traffic to the public Internet 14.

In the asynchronous IMT-2000 system to which the present invention is applied, another GPRS network subscriber subscribed to the mobile IP network 13 can access the GPRS network 12 to receive packet data service. In other words, the subscriber who has subscribed to the mobile IP service through the GPRS network 12 may communicate with the counterpart nodes even through another GPRS network after the mobile IP setting procedure and registration procedure.

2 is a diagram illustrating an embodiment of an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention.

As shown in FIG. 2, the external agent 131 supporting mobile IP in the asynchronous IMT-2000 system according to the present invention includes a GGSN matching unit 201 and an external agent unit that match the GGSN 123 of the GPRS network. The authentication unit 202 performing the authentication function of the, the charging information for the packet passing through the external agent 131, the charging processing unit 203 for transmitting the collected charging information, and transmits and receives by the diamond protocol Designate a routing table for the mobile node, specify a routing table for the mobile node, control the packet routing and tunneling control unit 205 for performing the tunnel setting / release function, and each functional block in the foreign agent, and And a mobile IP service registration unit 206 that performs signal processing of the IP basic function.

Looking at each component in detail, the GGSN matching unit 201 is connected between the GGSN 123 and the mobile IP service registration unit 206 of the GPRS network, in this case matching through a separate interface Gi + GGSN (123) do. Here, Gi + is a modified interface of Gi, which is an interface connecting the GPRS network to the Internet, and in the present invention, refers to an interface between the GGSN 123 and the external agent 131.

In particular, the GGSN matching unit 201 matches when the GPRS network subscriber requests the mobile IP service, and performs a separate interface processing function for supporting the mobile IP service. In addition, the mobile IP service registration procedure can be performed using information obtained through a separate interface Gi +.

The authentication unit 202 is connected to the mobile IP service registration unit 206 to generate a random number so as to perform a challenge / response function and perform an authentication algorithm related to the external agent 131. do. It also matches with the metadata protocol processing unit 204 for authentication.

And, the charging processing unit 203 is connected to the mobile IP service registration unit 206, activated by the signal of the mobile IP service registration unit 206, collects the charging information for the packet passing through the external agent 131, The collected billing information is transmitted through the diamond protocol processor 204.

Then, the metadata protocol processing unit 204 encodes the information transmitted from the mobile IP service registration unit 206 or the charging processing unit 203 into a metadata message, and transmits the information to the authentication and charging server 132, and the authentication and charging server ( Decode the received metadata message from 132 and transmits it to the mobile IP service registration unit 206 or billing processing unit 203.

The packet routing and tunneling control unit 205 is called by the mobile IP service registration unit 206, specifies a routing table for the mobile node 11, and performs a function of setting / releasing a tunnel.

The mobile IP service registration unit 206 controls each functional block in the external agent 131 and is connected to the mobile node 11 and the home agent 133 to perform signal processing of the mobile IP basic function. It connects to the authentication and charging server 132 through the diamond protocol processing unit 204.

3 is a diagram illustrating an embodiment of a signaling protocol stack used for an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention.

As shown in FIG. 3, a signaling protocol stack used for an external agent supporting mobile IP in the asynchronous IMT-2000 according to the present invention has five layers. First, the lowest layer, the L1 layer, the L2 layer, the IP layer, the User Datagram Protocol (UDP) and the Stream Control Transmission Protocol (SCTP) or Transmission Control Protocol (TCP) layer, and the Gi +, DIAMETER and MIP + layers.

The above five layers are compared with the layers of the same location of the mobile node 11, the GGSN 123, the authentication and billing server 132, and the home agent 133.

The mobile node 11, the GGSN 123, the external agent 131, the authentication and billing server 132, and the home agent 133 have different stacks of L1 and L2, respectively. The dual mobile node 11 has L1 and L2, which are layers of the GPRS radio access standard, according to the characteristics of the mobile node 11, and the GGSN 123 is L1, L2, which is a layer for communication with SGSN, the front end of the GPRS network. , Which follows the ATM layer. In addition, L1 and L2 for matching with the external agent 131 follow Ethernet.

In addition, as long as the external agent 131, the authentication and billing server 132, and the home agent 133 can support the IP layer, which is a higher layer, the lower layers L1 and L2 may follow any standard.

The third layer of each node is an IP layer, and IP here refers to Ipv4 (Internet Protocol Version 4).

In addition, in order to support the mobile IP service in the mobile node 11, a mobile IP protocol stack is necessary. The mobile IP protocol stack is recommended to use UDP for the lower layer. UDP used by the GGSN 123, the foreign agent 131, and the home agent 133 are all the same protocol.

Here, UDP is a communication protocol that provides only a limited service when messages are exchanged between computers in a network using IP. UDP is an alternative to TCP, and sometimes referred to as UDP / IP when used with IP. Like TCP, UDP uses IP to receive the actual data units called datagrams from one computer to another. However, unlike TCP, UDP does not provide services such as dividing a message into packets (datagrams), reassembling on the other side, and in particular does not provide an order of arriving data packets.

In addition, the mobile node 11 supports both the existing standardized standard and the standard in progress in order to support a better mobile IP service (MIP +). The mobile IP + protocol stack is built in the mobile node 11, the external agent 131, and the home agent 133 among the components of the mobile IP network system. Herein, the better mobile IP service (MIP +) will be described in more detail. The better mobile IP service of the present invention is not only an existing standardized mobile IP service standard, but also a discussion "ReverseTunneling for Mobile IP (RFC2344)". "," Mobile IPv4 Challenge / Response Extensions (RFC3012) "," Mobile IP Network Access Identifier Extension for IPv4 (RFC2794) ", IETF draft: draft-ietf-mobileip-aaa-key-03.txt:" AAA Registration Keys for Mobile IP ", draft-calhoun-aaa-diameter-15.txt:" DIAMETER Base Protocol "and draft-calhoun-aaa-diameter-mobileip-08.txt:" DIAMETER Mobile IP Extension ".

In addition, the GPRS Tunneling Protocol (GTP) is performed for packet data service on the path from the wireless data network controller 121 of the GPRS network to the GGSN 123, and the UDP and IP layers are used as the GTP lower protocols. .

In addition, in order to match the GGSN 123 and the external agent 131, the Gi + standard 307 made for better support of the mobile IP service in the GPRS network is used. The Gi + standard can support better mobile IP services in the GPRS network while minimizing the specifications of the GGSN 123 and the external agent 131.

The protocol used between the external agent 131 and the authentication and billing server 132 and the home agent 133 and the authentication and billing server 132 is a diamond protocol, and the lower layer is a stream control transmission protocol. Or Transmission Control Protocol (TCP) is used.

As such, the protocol, which is a protocol used between the external agent 131 and the authentication and billing server 132, and the home agent 133 and the authentication and billing server 132, is used for authentication, authorization verification, and billing in the Internet network. It also supports mobile IP as a protocol.

4 is a structural diagram of an embodiment of a traffic stack used for an external agent supporting mobile IP in an asynchronous IMT-2000 system according to the present invention.

As shown in FIG. 4, the traffic stack used for an external agent supporting mobile IP in the asynchronous IMT-2000 system according to the present invention includes four layers of L1, L2, IP, and IP in IP layers.

Here, the lower L1, L2 and IP layers are the same as the signal protocol stack of FIG. Accordingly, the traffic stacks of the mobile node 11, the GGSN 123, the home agent 133, and the counterpart node 41 are centered on the IP in IP tunnel as the top layer.

First, after the mobile node 11 completes the mobile IP service session establishment and registration procedure in the asynchronous IMT-2000 system, and the mobile node 11 executes an application such as an Internet connection, the mobile node 11 from the mobile node 11 The data packet passes through the GTP tunnel set in the GGSN 123 of the GPRS network through UDT / TCP, which is a transport layer, and passes through an IP in IP tunnel connecting the GGSN 123 and the external agent 131.

At this time, the IP in IP tunnel between the GGSN 123 and the external agent 131 is a bidirectional tunnel, and all data packets sent from the mobile node 11 are transmitted through the IP in IP tunnel between the GGSN 123 and the external agent 131. All packets sent through the foreign agent 131 and directed to the mobile node 11 are transmitted to the GGSN 123 through an IP in IP tunnel between the GGSN 123 and the foreign agent 131.

In addition, the traffic path between the foreign agent 131 and the home agent 133 is transmitted between the counterpart nodes 41 by IP routing when the mobile node 11 is a home subscriber. When the visitor accesses the GPRS network, the home agent 133 establishes a tunnel with the external agent 131. In this case, the basic tunneling protocol uses an IP in IP tunnel.

The IP in IP tunnel used in the present invention means that a tunnel is established between the destination address and the source address of the outer IP header by adding another IP header to the basic IP packet.

5A to 5B are flowcharts illustrating an embodiment of a mobile IP service for an external agent supporting mobile IP in the asynchronous IMT-2000 system according to the present invention.

First, a registration for a mobile IP service is required for the mobile IP service. Therefore, the registration process will be described first.

For mobile IP registration, the mobile node 11 which wants to receive better mobile IP (MIP +) service transmits a mobile IP service access request message to the GGSN 123 (501).

At this time, the mobile node 11 sets the service type of the message provided by the GPRS network to the mobile IPv4 service and transmits the message to the GPRS network (501). The GGSN 123 receiving the message transmits a mobile IP service start request message to the external agent 131 (502).

The GGSN matching unit 201 of the external agent 131 receiving the mobile IP service start request message transmits an agent advertisement message transmission request message to the mobile IP service register 206 (503), and receives the mobile IP service register. In step 206, a challenge request for authentication is made to the authenticator 202, and a result is received (504).

In response to the challenge request, the mobile IP service registration unit 206 receives the challenge value from the authenticator 202 (504), creates an agent advertisement message using the received challenge value, and generates the GGSN matching unit 201. In operation 505.

In order to transmit the agent advertisement message to the mobile node 11, the GGSN matching unit 201 transmits the agent advertisement message to the GGSN 123 in the mobile IP message transmission request message (506).

The GGSN 123 transmits the agent advertisement message included in the mobile IP message transmission request message to the mobile node 11 (507).

Receiving the agent advertisement message (507), the mobile node 11 transmits a mobile IP registration request message, which is a mobile IP + protocol, to the GGSN 123 of the GPRS network (508). The mobile IP message is converted into a mobile IP message transmission request message and transmitted to the GGSN matching unit 201 of the foreign agent 131 (509).

The GGSN matching unit 201 of the external agent 131 interprets the mobile IP message transmission request message, which is a Gi + matching message, and transmits the mobile IP registration request message processing request message, which is a pure mobile IP + message, to the mobile IP service registration unit 206. (510).

The mobile IP service registration unit 206 examines whether the challenge value included in the mobile IP registration request message processing request message is the same as the challenge value transmitted in the agent advertisement message of 505 and generates a diametric message. The better mobile IP message is interpreted to generate a diamond message transmission request message and transmitted to the diamond protocol processing unit 204 in the external agent 131 (511).

The diamond protocol processing unit 204 converts the received diamond message transmission request message into an authentication (Authentication, Authorization) -mobile node request message (MobileNodeRequest), which is a metadata message, and transmits it to the authentication and billing server 132 ( 512).

The authentication and billing server 132 processes the contents included in the received AA-Mobile Node Request message, converts it into a Home Agent MIPRequest message, and sends it to the Home Agent 133 (513). The agent 133 includes the mobile IP registration response in the HomeAgentMIPAnswer message, which is a response message, and transmits the mobile IP registration response to the authentication and billing server 132 (514).

The authentication and billing server 132 converts the received Home Agent Mobile IP Response (HomeAgentMIPAnswer) message into an AA-Mobile Node Response (MobileNodeAnswer) message and transmits the message to the protocol manager 204 of the external agent 131 (515). ).

The transmitted AA-Mobile Node Response (MobileNodeAnswer) message is analyzed by the metadata protocol processing unit 204, and converted to a metadata message processing request message to the mobile IP service registration unit 206 and transmitted (516).

Through the above process, the mobile IP service is registered with the mobile node 11.

After performing the above registration process, the mobile IP service registration unit 206 determines whether the mobile IP registration succeeds or fails, and if it fails, sends a mobile IP registration response message to the GGSN matching unit (517), and the mobile IP registration succeeds. In operation 518, the authentication unit 206 requests this to interpret the session key information obtained from the received message message.

In addition, when the authentication unit 202 interprets the associated session key, the mobile IP service registration unit 206 confirms the authenticator included in the home agent mobile IP response message, and transmits a charging start request message to the charging processing unit 203. After receiving the charging start request response message for the charge collection start from the charging processing unit 203 (520), the packet routing or tunneling registration for the mobile node 11 is registered with the packet routing and tunneling control unit 205. It receives a response to the request (521).

In step 521, the packet routing and tunneling control unit 205, which is requested to register packet routing or tunneling from the mobile IP service registration unit 206, analyzes the information included in the routing information registration request and establishes a tunnel with the home agent 133. In operation 522, routing information for the mobile node 11 to the GGSN 123 is set up.

Meanwhile, the mobile IP service registration unit 206 stores related session information and subscriber information, and requests the next challenge from the authentication unit 202 (523).

The mobile IP service registration unit 206 also transmits a mobile IP registration response message including related session information and subscriber information to the GGSN matching unit 123 (524).

The GGSN matching unit 123 transmits a mobile IP registration response message transmission request message requesting the mobile node 11 to transmit mobile IP registration response messages 517 and 524 to the GGSN 123 through Gi + matching. The GGSN 123 transmits the mobile IP registration response messages 517 and 524 to the mobile node 11 through the GPRS network using the GTP ID information included in the Gi + match (526). .

After receiving the mobile IP registration response messages 517 and 524, the mobile node 11 determines whether the mobile IP service registration is successful and attempts to connect to the other node (527).

Accordingly, when an application such as an Internet connection is executed, the mobile node 11 to the GGSN 123 through GTP, the GGSN 123 and the external agent 131 through IP in IP, and the external agent 131 ) Is directly routed to the other node.

When a message is transmitted from the opposite node to the mobile node 11, the message is transmitted to the home agent 133 by general routing. In the home agent 133, when the mobile node 11 is the home network, the external agent is transmitted through the general IP routing function. The packet is transmitted to the external agent 131 through the IP in IP tunnel established between the home agent 133 and the external agent 131. 131 transmits the packets to the GGSN 123 again through the IP in IP tunnel, and the GGSN 123 transmits the packets back to the corresponding mobile node 11 through the GTP.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

The present invention as described above, by building an external agent that is easy to accept a new standard for mobile IP while minimizing the change to the existing standard for mobile IP service support, compared to the protocol currently standardized in asynchronous IMT-2000 There is an effect that can support a better mobile IP service that supports many specifications.

In addition, the present invention, when building an external agent, it is easy to interface with other wireless access network, and the service can be easily expanded by separating the support of the standard protocol for supporting the basic mobile IP service and authentication support. There is.

Claims (11)

In the external agent device used in the asynchronous mobile communication system, Mobile IP service registration means for controlling internal means of the external agent device and performing signal processing for mobile IP (IP); Network matching means connected with the mobile IP service registration means to match an asynchronous mobile communication network; Authentication protocol processing means for allowing the external agent device to transmit and receive an authentication and billing server of the mobile IP network using an authentication protocol; Authentication means connected to said mobile IP service registration means and said authentication protocol processing means, for performing an authentication function of an external agent unit under control of said mobile IP service registration means; Connected to the mobile IP service registration means and the authentication protocol processing means, collects charging information for a packet passing through the foreign agent under the control of the mobile IP service registration means, and charges for transmitting the collected charging information; Processing means; And Packet routing and tunneling control means for designating a routing table for a mobile node and performing a tunnel setting / release function by the control of the mobile IP service registration means. External agent device that supports the mobile IP service in the asynchronous mobile communication system including a. The method of claim 1, The authentication means, Asynchronous next-generation mobile communication according to the control of the mobile IP service registration means, generating a random number to perform a challenge / response function and performing an authentication algorithm associated with the external agent device External agent device that supports mobile IP services in the system. The method according to claim 1 or 2, The asynchronous mobile communication network, An external agent device supporting a mobile IP service in an asynchronous mobile communication system, characterized in that it is a GPRS (General Packet Radio Service) network. The method of claim 3, wherein The network matching means, Mobile IP in an asynchronous mobile communication system characterized by using a Gi + interface modified from the Gi interface used between the GPS network and the Internet for matching with the GPS network. External agent devices that support the service. The method according to claim 1 or 2, The authentication protocol is an external agent device supporting a mobile IP service in an asynchronous mobile communication system, characterized in that the DIAMETER protocol. A mobile IP service method using an external agent device used in an asynchronous mobile communication system, A first step of the external agent registering a mobile IP service of the mobile node with a home agent by a mobile IP service start request signal of the mobile node received from the asynchronous mobile communication network through a network matching unit; A second step of transmitting a signal through the network matching unit to notify the mobile node of the failed registration of the mobile IP through the asynchronous mobile communication network when the registration of the mobile IP service of the first step fails; And A third step of enabling access to the other node of the mobile node through routing and tunneling registration when the mobile IP service registration of the first step is successful; Mobile IP service method using an external agent device used in the asynchronous mobile communication system comprising a. The method of claim 6, The first step is, A fourth step of the network matching unit receiving a mobile IP service start request signal of a mobile node from an asynchronous mobile communication network and requesting an agent advertisement message transmission to a mobile IP service register; A fifth step of receiving, by the mobile IP service registration unit requesting to transmit the agent advertisement message of the fourth step, a challenge value from an authentication unit, using the same, to generate an agent advertisement message and transmitting the generated agent advertisement message through the network matching unit; A sixth step of receiving, by the mobile IP service registration unit, a mobile IP registration message processing request from the mobile node receiving the agent advertisement message of step 5 through an asynchronous mobile communication network, and transmitting an authentication message to an authentication protocol processor; A seventh step of transmitting, by the authentication protocol processor, an authentication request message to an authentication and charging server to cause a home agent to generate a mobile IP registration response; An eighth step of receiving, by the authentication protocol processor, a mobile IP registration response message generated in the seventh step through an authentication and charging server; And A ninth step in which the mobile IP registration processing unit analyzes and receives the mobile IP registration response message received in step 7 by the authentication protocol processing unit and performs mobile IP registration for the mobile node; Mobile IP service method using an external agent device used in the asynchronous mobile communication system comprising a. The method of claim 7, wherein The third step, A tenth step of checking, by the mobile IP registration processing unit, whether the mobile IP registration is successful for the mobile node and requesting the authentication unit to interpret the session key information obtained from the mobile IP registration response message received in the ninth step; ; An eleventh step of allowing the mobile IP registration processing unit to start charging by transmitting a charging start request message to a charging processing unit and receiving a response thereto; The mobile IP registration processing unit, requesting packet routing or tunneling registration for the mobile node from a packet routing and tunneling control unit to set up packet routing or tunneling registration information; And The mobile IP registration processing unit stores session information and subscriber information obtained through each process, and transmits a mobile IP registration response message including the session information and subscriber information to establish a connection between the mobile node and the counterpart node. 13th Step to Set Mobile IP service method using an external agent device used in the asynchronous mobile communication system comprising a. The method according to any one of claims 6 to 8, The asynchronous mobile communication network, Mobile IP service method using an external agent device used in an asynchronous mobile communication system, characterized in that the GPRS (General Packet Radio Service) network. The method according to any one of claims 6 to 8, The authentication protocol is a mobile IP service method using an external agent device used in an asynchronous mobile communication system, characterized in that the DIAMETER protocol. In an external agent device for use in an asynchronous mobile communication system having a processor, A first function of the external agent to register a mobile IP service of the mobile node to a home agent by a mobile IP service start request signal of the mobile node received from the asynchronous mobile communication network through a network matching unit; A second function of transmitting a signal through a network matching unit to notify a mobile node of a failed registration of a mobile IP through an asynchronous mobile communication network when registration of the mobile IP service by the first function fails; And A third function that enables connection of the mobile node to a counterpart node through routing and tunneling registration when the mobile IP service registration by the first function is successful; A computer-readable recording medium having recorded thereon a program for realizing this.