WO2007134498A1

WO2007134498A1 - A system and method for implementing the mobile ip access

Info

Publication number: WO2007134498A1
Application number: PCT/CN2006/003228
Authority: WO
Inventors: Xiuli Xu
Original assignee: Zte Corporation
Priority date: 2006-05-24
Filing date: 2006-11-30
Publication date: 2007-11-29
Also published as: CN101079704A; CN101079704B

Abstract

A system for implementing the mobile IP access, includes: an access server, a mobile terminal without the mobile IP function, an AAA server and a home agent. The mobile terminal without the mobile IP function transmits information to the access server to request to access the system; the access server transmits the access request message to the AAA server; the AAA server returns an authorization information to the access server; after the access server receives the authorization information, it represent the mobile terminal to transmit the mobile IP register request message to the home agent; the home agent returns the mobile IP register acknowledge message to the access server. The present invention also provides a method for implementing the mobile IP access. According to the system and method of the present invention, it provides a facile method to implement the mobile IP service for the terminal without the mobile IP function.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system and method for terminal access in the field of communications, and more particularly to a system and method for providing mobile IP access for a terminal that does not have a mobile IP function. Background The traditional IP technology is for the mutual communication between fixed nodes, and is not applicable to mobile nodes. Therefore, the IETF (Internet Engineering Task Force) network working group proposed the RFC2002 standard in October 1996, which elaborated on the principle, implementation and various details of mobile IP. Simply put, mobile IP is to allow mobile nodes to move while not disconnecting, and to correctly send and receive packets. The mobile node can be a computer device connected to the Internet, such as a PC, a laptop, etc.; or a portable terminal: a device such as a cellular phone, a pager, a palmtop, a PDA, or the like. Mobile IP has deep integration of mobile technology and IP technology. In the mobile IP conference, each mobile node has a unique home address, and its home address is unchanged when the mobile node moves. Each mobile node on the home network link must also have a home agent to maintain current location information for it, which requires the introduction of a care-of address. When the mobile node is connected to a foreign network link, the care-of address is used to identify the location of the mobile node now for routing. The association of the mobile node's home address with the current care-of address is called mobile binding or short-term binding. When the mobile node obtains a new care-of address, it registers with the home agent through the binding, so that the home agent can know the current location of the mobile node in time. When the mobile node is connected on the home network link, the mobile node can work in the same way as the fixed node without using the mobile IP function. When a mobile node is connected to a foreign network link, it typically finds a foreign agent on the foreign link using an operation called "agent discovery" and registers with the foreign agent. The IP address is used as its own care-of address. After the mobile node obtains the care-of address, it tells the home agent its own care-of address through the registration operation. Thus, when there is a data packet addressed to the mobile node's home address, the home agent intercepts the data packet and transmits the data packet to the mobile node through the tunnel according to the registered care-of address. Although the mobile IP technology is very mature, there are many devices supporting mobile IP functions, but the use of mobile IP faces a very big obstacle: Many terminals do not have the function of mobile IP; The application of mobile IP technology is greatly hindered. Proxy mobile IP technology is created to solve this situation. This technology provides mobile IP access for terminals that do not have mobile IP capabilities. Patent No. "US6978128", "System and method to allow simple IP mobile nodes to operate seamlessly in a mobile IP network with true roaming capabilities", discloses a system and method for implementing mobile IP. In this patent, by adding a proxy server, the foreign agent FA implements the function of mobile IP for the terminal without the mobile IP function, wherein the proxy server determines the home authentication, authorization and accounting server. The AAA address determines the address of the home agent HA and determines the home address of the mobile terminal. In actual application, the proxy server forwards the authentication and accounting information of the system, and specifies an IP address for the mobile terminal. In practical applications, the authentication and charging information is directly sent by the authentication and accounting client to the authentication, authorization, and accounting server AAA. If transited by the proxy server, the interaction time between the authentication and accounting client and the authentication, authorization and accounting server will be extended. On the other hand, in the mobile IP access mode, the assignment of the user's home IP address is generally determined by the home agent HA. Thus, the home agent HA can flexibly determine the home address of the mobile terminal and provide routing services for its determined home address. If the IP address is assigned to the terminal by other nodes, it may happen that the assigned IP address is not in the home network, and the home agent HA cannot provide a routing service for the terminal. SUMMARY OF THE INVENTION In view of the above drawbacks of the month 1, the object of the present invention is to provide a system and method for implementing mobile IP access for a terminal that does not have a mobile IP function. To achieve the above object, the present invention provides a system for implementing mobile IP access, the system comprising: an access J1 server, a mobile terminal without a mobile IP function, an authentication, authorization and accounting server, a home agent The mobile terminal that does not have the mobile ip function is connected to the access server through the wireless network, and the access server, the authentication, authorization, and accounting server, and the home agent are connected through the IP network; and the access server is used to implement a foreign agent, providing access for a mobile terminal not having a mobile IP function, and transmitting a registration request of the mobile IP on behalf of the mobile terminal having no mobile IP function, and maintaining the mobile terminal during the online operation of the mobile terminal without the mobile IP function Mobile IP information; An authentication, authorization, and accounting server, configured to receive a mobile IP access request sent by the access server, and return authorization information to the access server; the home agent is configured to receive the mobile IP registration request information sent by the access server, and Returning a mobile IP registration response message to the access server; wherein, the mobile terminal not having the mobile IP function sends an information request access system, and the access server determines that the user requests access, sends an access request message to the authentication, The authorization and accounting server, the authentication, authorization and accounting server returns the authorization information to the access server. After receiving the authorization information, the access server sends a mobile IP registration request message to the home agent on behalf of the mobile terminal, and the home agent registers the mobile IP. The reply message is returned to the access server. The authentication, authorization, and accounting server records information that the mobile terminal implements the proxy mobile IP function, and the information includes information about whether the mobile terminal is allowed to use the proxy mobile IP function. Wherein, if the information that the mobile terminal implements the proxy mobile IP function recorded by the authentication, authorization, and accounting server includes information that allows the mobile terminal to use the proxy mobile IP function, the information further includes key information between the mobile terminal and the home agent. IP address information of the mobile terminal home agent. The key information between the mobile terminal and the home agent included in the information that allows the mobile terminal to use the proxy mobile function is sent to the access server in an encrypted manner. The mobile IP registration response information sent by the home agent to the access server includes: a home IP address determined for the mobile terminal, and the home IP address is sent to the mobile terminal by using the access server. The access server is a packet data monthly service node PDSN in the CDMA system. To achieve the above object, the present invention also provides a method for implementing mobile IP access, including the following steps:

(1) The mobile terminal sends an information request access system;

(2) The access server constructs an access request message and sends it to the authentication, authorization, and accounting server;

(3) The authentication, authorization, and accounting server receives the access request message of the access server and performs authentication; if the authentication fails, the access denied message is sent to the access server, and the process ends; if the authentication is successful, Return authorization information to the access server; (4) If the access server receives the information that allows the mobile terminal to use the proxy mobile IP function, then the mobile terminal sends a mobile IP registration request message to the home agent on behalf of the mobile terminal, and continues to step (5); no, the access server provides the user with the access server Non-proxy mobile IP service, ending the process;

(5) The home agent returns a mobile IP registration response message to the access server. The step (3) is specifically: the authentication, authorization, and accounting server receives the access request message of the access server, performs authentication, and if the authentication fails, sends an access reject message to the access server; If it succeeds, the mobile terminal performs the information of the proxy mobile IP function according to the information recorded by the mobile terminal, and returns the information of the mobile terminal using the proxy mobile IP function to the access server. The authentication, authorization, and accounting server in step (3) returns, to the access server, information that the mobile terminal uses the proxy mobile IP function, where the information includes key information between the mobile terminal and the home agent, and the attribution of the mobile terminal. IP address information. The authentication, authorization, and accounting server in step (3) returns, to the access server, information that the mobile terminal uses the proxy mobile IP function, and the key information between the mobile terminal and the home agent included in the information is sent by using an encryption method. Connect to the server. The step (4) is specifically: the access server constructs a mobile device on behalf of the mobile terminal according to the key information between the mobile terminal and the home agent returned by the authentication, authorization, and accounting server and the IP address information of the home agent of the mobile terminal. The IP registration request message is sent to the home agent. The mobile IP registration request information further includes authentication extension information between the mobile terminal and the home agent calculated by the access server according to the key information. The step (4) is specifically: the access server determines to provide a proxy mobile IP service for the terminal, and the access server immediately sends a mobile IP registration request message to the home agent. The step (4) is specifically: the access server determines to provide a proxy mobile IP service for the mobile terminal, and the access server sends a mobile IP registration request message to the home agent when the mobile terminal requests the IP address. The mobile IP registration response message returned by the home agent to the access server in the step (5) includes: a home IP address of the mobile terminal determined by the home agent, and the home IP address is sent to the mobile terminal by using the access server. Step (5) further includes the step of: the mobile terminal accesses the system after obtaining the home IP address from the access server, and performs data service: before the access server reaches the lifetime of the mobile terminal's home IP address or The access server periodically sends a re-registration request information of the mobile IP to the home agent on behalf of the mobile terminal during the lifetime of the home IP address of the mobile terminal, where the re-registration request information includes the home IP address of the mobile terminal. Step (5) further includes the step B: the mobile terminal ends the data service exiting the system, and the access server sends the mobile IP registration request information with the survival time of zero to the home agent on behalf of the mobile terminal, and the home agent sends the mobile IP registration response information. Return to the access server and delete the binding of the mobile IP of the mobile terminal. According to the system for implementing mobile IP access according to the present invention, since the proxy server is not used, system authentication and charging messages are prevented from being forwarded through the proxy server, thereby causing authentication and accounting between the client and the authentication, authorization and accounting server. The authentication and billing information interaction time is extended, and the home agent is

The HA determines the home address of the mobile terminal, which is beneficial for the home agent to provide a reasonable route for the mobile terminal. This is to ensure that the IP address remains unchanged when the mobile terminal crosses the network, and it is possible to keep the data service uninterrupted. The system does not need to add additional equipment, and can provide mobile IP services for terminals that do not have mobile IP functions based on system software upgrades, with minimal impact on the system. According to the method of the present invention for implementing mobile IP access, in the CDMA system, the access server is a packet data serving node PDSN, and when the authentication response or the IP address request of the mobile terminal is received, the mobile terminal transmits the mobile terminal. The IP registration request is made; when the IP address is requested in the IPCP (IP Control Protocol) phase of the mobile terminal, the access server returns the home IP address of the mobile terminal determined in the mobile IP registration response returned by the home agent HA to Mobile terminal. This provides a convenient way for CDMA systems to implement mobile IP services for terminals that do not have mobile IP capabilities. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a system configuration diagram for implementing mobile IP access according to the present invention; FIG. 2 is a flowchart of a system for implementing mobile IP access according to the present invention; FIG. 3 is a proxy mobile IP implementation according to the present invention. A functional mobile IP registration request part message is illustrated; FIG. 4 is a mobile IP registration response part message example implementing the proxy mobile IP function according to the present invention; 5 is a flow diagram of implementing proxy mobile IP functionality in a CDMA system in accordance with the present invention; and FIG. 6 is another flow diagram of implementing proxy mobile IP functionality in a CDMA system in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The implementation of the technical solution according to the present invention will be further described in detail below with reference to the accompanying drawings. FIG. 1 shows a system configuration diagram for implementing a proxy mobile IP function according to the present invention. As shown in FIG. 1, the system includes: a mobile terminal MT 11 connected to an access server/foreign proxy AS/FA 12 via a wireless network, wherein the mobile terminal MT 11 does not have a mobile IP function. The access server/foreign agent AS/FA 12 implements the foreign agent FA function, and provides an access service for the mobile terminal MT 11 to send an access request message to the authentication, authorization, and accounting server AAA 14. The access server/foreign agent AS/FA 12, on behalf of the mobile terminal, sends a registration request for the mobile ip to the home agent HA 13 and maintains its mobile ip related information while the terminal is online. The authentication, authorization, and accounting server AAA 14 provides the user with an authentication, authorization, and accounting service, and authenticates the terminal when receiving the terminal access request sent by the access server/foreign agent AS/FA12, and Carry out the corresponding authorization, authentication,

When the terminal MT 11 is authenticated, an authorization including the terminal agent mobile IP function information is performed. The home agent HA 13 accepts the mobile IP registration request sent by the access server/foreign agent AS/FA12, and performs a mobile IP registration response, cooperates with the access server/foreign agent AS/FA12 to serve as a terminal without mobile IP function. Provide monthly services for mobile IP. 2 shows a system flow diagram for implementing proxy mobile IP functionality in accordance with the present invention. As shown in FIG. 2, the specific steps are as follows: Step 201: The mobile terminal requests access to the system; Step 202: After receiving the access request of the mobile terminal, the access server/foreign agent sends an access request message to the authentication, 4 ft. Right and billing server; Step 203: The authentication, authorization, and accounting server returns an access response message to the access server/foreign agent, where the message includes authorization information of the mobile terminal using the proxy mobile IP function. Step 204: The access server/foreign agent is authenticated according to the authentication And the response message returned by the authorization and accounting server, determining that the mobile terminal can provide the proxy mobile IP monthly service, and sending the mobile IP registration request message to the home agent on behalf of the mobile terminal; Step 205: The home agent will respond to the mobile IP registration The message is sent to the access server/foreign agent; Step 206: The terminal obtains the home IP address from the access server/foreign agent, accesses the system, and performs data service; Step 207: When the mobile IP lifetime reaches Previously, when the re-registration time arrives, the access server/foreign agent sends a mobile IP registration request to the home agent on behalf of the mobile terminal, requesting mobile IP re-registration of the mobile terminal; Step 208: The home agent sends a mobile IP registration response to the connection Into the server / eve agent, at the same time refresh the mobile IP binding information of the mobile terminal; Step 209: End Ending the data service, exiting the system; Step 210: The access server/foreign agent sends a registration request of Lifetime=0 to the home agent on behalf of the mobile terminal, requesting to cancel the mobile binding of the mobile terminal; Step 211: The home agent will respond with a mobile IP registration Send to the access server/foreign agent, and delete the binding information of the mobile IP of the mobile terminal. FIG. 3 shows an example of a mobile IP registration request section 4 implementing the Proxy Mobile IP function according to the present invention. As shown in FIG. 3, 301 represents a mobile IP address of the terminal, and the IP address may be an IP address specified by the mobile terminal; an authentication IP address assigned to the mobile terminal by the authentication, authorization, and accounting server when the response is accessed; or It is 0.0.0.0, that is, the mobile terminal requests the home agent to assign the home IP address to the mobile terminal.

302 denotes the address of the home agent HA, and the information of this field is sent by the authentication, authorization and accounting server to the access server when the access response. 303 represents the IP address of the foreign agent FA. In the present invention, the access server implements the foreign agent function, that is, 303 is the IP address of the access server.

304 represents an extension of the registration request, which must include the Mobile-Home Authentication Extension, which is sent by the authentication, authorization, and accounting server to the access server when the access response is received. The meaning of the other fields is the same as that specified in the RFC2002 protocol. Figure 4 shows an example of a Mobile IP Registration Response Part message implementing the Proxy Mobile IP function in accordance with the present invention. As shown in FIG. 4, 401 is a home IP address of the mobile terminal determined by the home agent HA, and the IP address can be dynamically allocated by the home agent HA; or requested by the home agent HA to the authentication, authorization, and accounting server; or the home agent. The HA is internally configured for the mobile terminal user. This configuration value must be the same as the configuration value of the corresponding mobile terminal user recorded in the authentication, authorization, and accounting server.

402 denotes the IP address of the home agent HA.

404 represents an extension of the registration response, which must include the Mobile-Home Authentication Extension, which is the authentication extension. The meaning of the other fields is the same as that specified in the RFC2002 protocol. The following embodiments take the CDMA system as an example, but it should be understood that the present invention is not limited to the CDMA system, and all the systems that use the access server to implement proxy mobile IP access can apply the method provided by the present invention to implement the mobile IP function. . In the CDMA system, a terminal with no mobile IP function adopts a simple IP access mode. If the system implements the proxy mobile IP function for the terminal, the terminal still accesses by means of simple IP. Figure 5 is a flow chart showing the implementation of the Proxy Mobile IP function in a CDMA system in accordance with the present invention. In this embodiment, after the packet data serving node PDSN receives the access response returned by the authentication, authorization, and accounting server AAA, the mobile terminal immediately performs a proxy mobile IP registration request on behalf of the mobile terminal. The specific steps are as follows: Step 501: Perform negotiation between an LCP (Link Control Protocol) and an authentication process between the mobile terminal and the packet data serving node PDSN. Step 502: The packet data serving node PDSN sends an access request message to the authentication, authorization, and accounting server AAA. Step 503: The authentication, authorization, and accounting server AAA sends an access response message to the packet data serving node PDSN. The method includes: the mobile terminal uses the proxy mobile IP function authorization information; Step 504: the packet data serving node PDSN sends the authentication result to the mobile terminal; Step 505: The packet data serving node PDSN sends the proxy mobile IP registration request to the mobile terminal on behalf of the mobile terminal Proxy HA; Step 506: The home agent HA sends a mobile IP registration response message to the packet data serving node PDSN, where the registration response message includes the home IP address of the mobile terminal determined by the home agent HA; Step 507: Mobile terminal and packet data monthly service The IP data (IP Control Protocol) phase is negotiated between the node PDSNs, and the packet data monthly service node PDSN sends the home IP address information of the mobile terminal returned by the home agent HA to the mobile terminal. Step 507 begins at the same time. Figure 6 illustrates another flow diagram for implementing Proxy Mobile IP functionality in a CDMA system in accordance with the present invention. In this embodiment, after the packet data month service node PDSN receives the IP address request from the mobile terminal, the mobile terminal performs a proxy mobile IP registration request on behalf of the mobile terminal. The specific steps are as follows: Step 601: The LCP and the authentication process are negotiated between the mobile terminal and the packet data serving node PDSN. Step 602: Packet data service node; The PDSN sends an access request message to the authentication, authorization, and accounting. The fee server AAA; Step 603: The authentication, authorization and accounting server AAA sends an access response message to the packet data serving node PDSN, including the authorization information of the mobile terminal using the proxy mobile IP function; Step 604: The packet data serving node PDSN will The authentication result is sent to the mobile terminal; Step 605: The IPCP phase negotiation is performed between the mobile terminal and the packet data serving node PDSN; Step 606: When the terminal requests the IP address, the packet data node PDSN represents the mobile terminal. Sending a proxy mobile IP registration request to the home agent HA; Step 607: The home agent HA sends a mobile IP registration response message to the PDSN, the registration response message includes a home IP address of the mobile terminal determined by the home agent; and step 608: packet data service The node PDSN transmits the home IP address information of the mobile terminal returned by the home agent HA to the mobile terminal. According to the system for implementing mobile IP access according to the present invention, since the proxy server is not used, the system authentication and the charging message are forwarded through the proxy server, thereby causing the authentication and accounting client and the authentication, authorization and accounting server. The time between the authentication and the charging information interaction time is extended; and the home agent HA determines the home address of the mobile terminal, which is beneficial for the home agent to provide a reasonable route for the mobile terminal, so that when the mobile terminal crosses the network, the IP address remains unchanged. Change, so that the terminal without the mobile IP function can keep the data service uninterrupted when switching the roaming in the network; the system does not need to add additional equipment, and can provide the mobile terminal with no mobile IP function on the basis of the system software upgrade. IP services have the least impact on the system. According to the method for implementing mobile IP access according to the present invention, in the CDMA system, the access server is a packet data serving node PDSN, and when receiving an authentication response or an IP address request of the mobile terminal, transmitting a mobile IP registration request on behalf of the mobile terminal; When the IP address of the mobile terminal is requested by the IPCP, the access server returns the home IP address of the mobile terminal determined in the mobile IP registration response returned by the home agent HA to the mobile terminal. This avoids the phenomenon that the home agent cannot accurately provide routing for the mobile terminal by determining the home IP address of the mobile terminal by the proxy server in the prior art, which is a terminal in the CDMA system that does not have the mobile IP function. Implementing a mobile IP service provides a convenient way. The above are only the embodiments of the present invention, and are not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

Claims

A system for implementing mobile IP access, characterized in that the system comprises:

Access server, mobile terminal without mobile IP function, maintenance, authorization and accounting server, and home agent,

The mobile terminal that does not have the mobile IP function is connected to the access server by using a wireless network, and the access server, the authentication, authorization, and accounting server, and the home agent are connected by using an IP network;

The access server is configured to implement a foreign agent, provide access for the mobile terminal without the mobile IP function, and send a registration request of the mobile IP on behalf of the mobile terminal that does not have the mobile IP function, and The mobile terminal without the mobile IP function maintains the mobile IP information of the mobile terminal during the online period;

The authentication, authorization, and accounting server is configured to receive a mobile IP access request sent by the access server, and return authorization information to the access server;

The home agent is configured to receive mobile IP registration request information sent by the access server, and return a mobile IP registration response message to the access server;

The mobile terminal that does not have the mobile IP function sends information to the access server, requests an access system, and the access server sends an access request message to the authentication, authorization, and accounting server. The authentication, authorization, and accounting server returns authorization information to the access server, and after receiving the authorization information, the access server sends a mobile IP registration request message to the attribution on behalf of the mobile terminal. And the home agent returns a mobile IP registration response message to the access server. The system for implementing mobile IP access according to claim 1, wherein the authentication, authorization, and accounting server records information that the mobile terminal implements a proxy mobile IP function, and the information includes whether the mobile terminal is allowed to use the proxy. Mobile IP function information. The system for implementing mobile IP access according to claim 2, wherein if the information of the mobile terminal using the proxy mobile IP function includes information allowing the mobile terminal to use the proxy mobile IP function, the information further includes the mobile terminal Key information and the home agent IP address information of the mobile terminal home agent.

4. The system for implementing mobile IP access according to claim 3, wherein the information allowing the mobile terminal to use the proxy mobile IP function includes the secret between the mobile terminal and the home agent The key information is sent to the access server in an encrypted manner.

The system for implementing mobile IP access according to claim 1, wherein the mobile IP registration response information sent by the home agent to the access server comprises: a home IP address determined for the mobile terminal The home IP address is sent to the mobile terminal by using the access server.

The system for implementing mobile IP access according to any one of claims 1 to 5, wherein the access server is a packet data monthly service node PDSN in a CDMA system.

A method for implementing mobile IP access, comprising the steps of:

(1) The mobile terminal sends a message requesting access to the system;

(2) the access server constructs an access request message and sends it to an authentication, authorization, and accounting server;

(3) The authentication, authorization, and accounting server performs authentication after receiving the access request message from the access server, and if the authentication fails, sending an access reject message to the connection. Entering the server, ending the process; if the authentication is successful, returning authorization information to the access server;

(4) if the access server receives information that allows the mobile terminal to use the proxy mobile IP function, then the mobile terminal sends a mobile IP registration request message to the home agent on behalf of the mobile terminal, and continues with step (5); otherwise, the access The server provides the user with a non-proxy mobile IP service, ending the process;

(5) The home agent returns a mobile IP registration response message to the access server.

8. The method for implementing mobile IP access according to claim 7, wherein said step

(3) Specifically: the authentication, authorization, and accounting server receives the access request message of the access server, and then performs authentication, and if the authentication fails, sending an access reject message to the Said access server; if the authentication is successful, implementing proxy transfer according to the recorded mobile terminal The information of the IP function returns information of the mobile terminal using the proxy mobile IP function to the access server.

9. The method for implementing mobile IP access according to claim 7 or 8, wherein the step

(3) The authentication, authorization, and accounting server returns, to the access server, information that the mobile terminal uses the proxy mobile IP function, where the information includes key information between the mobile terminal and the home agent. IP address information of the home agent of the mobile terminal.

The method for implementing mobile IP access according to claim 9, wherein the step (4) is specifically: the mobile terminal returned by the access server according to the authentication, authorization, and accounting server The key information with the home agent and the IP address information of the home agent of the mobile terminal are sent to the home agent on behalf of the mobile terminal constructing a mobile IP registration request message.

The method for implementing mobile IP access according to claim 10, wherein the mobile IP registration request information further includes the mobile terminal and the home calculated by the access server according to the key information. Authentication extension between agents.

12. The method for implementing mobile IP access according to claim 7, wherein the step

(4) Specifically: when the access server determines that the mobile terminal provides the proxy mobile IP, the access server immediately sends a mobile IP registration request message to the home agent.

13. The method for implementing mobile IP access according to claim 7, wherein the step

(4) specifically: when the access server determines to provide the mobile terminal with a proxy mobile IP service, the access server sends a mobile IP registration request message to the home when the mobile terminal requests an IP address ^ ₁ rational.

14. The method for implementing mobile IP access according to claim 7, wherein: the step

(5) The mobile IP registration response message returned by the home agent to the access server includes: a home IP address of the mobile terminal determined by the home agent, where the home IP address passes the access service The device is sent to the mobile terminal.

15. The method for implementing mobile IP access according to claim 7, wherein: the step (5) Also includes step A:

After obtaining the home IP address from the access server, the mobile terminal accesses the system and performs data service.

When the access server reaches the lifetime of the home IP address of the mobile terminal or the access time of the access server is at the home IP address of the mobile terminal, 4 the mobile terminal period The re-registration request information of the mobile IP is sent to the home agent, where the re-registration request information includes the home IP address of the mobile terminal. The method for implementing mobile IP access according to claim 7 or 15, wherein the step (5) further comprises the step B:

Ending, by the mobile terminal, the data service exiting the system, the access server transmitting, on behalf of the mobile terminal, mobile IP registration request information with a lifetime time of zero to the home agent, the home agent transmitting mobile IP registration response information Returning to the access server, and simultaneously deleting the binding of the mobile terminal's mobile IP.