WO2017143902A1

WO2017143902A1 - Evolved packet data gateway and cross evolved packet data gateway switching method and system

Info

Publication number: WO2017143902A1
Application number: PCT/CN2017/072870
Authority: WO
Inventors: 朱亚兵; 刘其锋; 李道红
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-02-26
Filing date: 2017-02-03
Publication date: 2017-08-31
Also published as: CN107135524A

Abstract

Disclosed in an embodiment of the invention are an evolved packet data gateway (ePDG) and cross ePDG switching method and system, and a computer storage medium. The device comprises: when a terminal moves from a first access point to a second access point, a second ePDG having the second access point receives a message from the terminal, the message comprising an address of a first ePDG having the first access point; the second ePDG acquires, according to the address of the first ePDG, parameter information of the first ePDG, the parameter information comprising an address of a PDN gateway accessed by the terminal, an identifier of an IPsec tunnel connecting the terminal with the first ePDG, and an identifier of a GTP tunnel connecting the first ePDG with the PDN gateway; the second ePDG establishes a connection with the terminal according to the parameter information; and the second ePDG establishes a connection with the PDN gateway according to the parameter information. By using the invention, after a UE unit has performed cross ePDG switching, there is no need to reestablish an IPsec tunnel and a GTP tunnel, and an operation currently performed by the UE is not interrupted.

Description

Method and system for switching packet data gateway and cross-packet data gateway

Technical field

The present invention relates to the field of network communications, and in particular, to a packet data gateway, a handover method and system for a cross-packet data gateway, and a computer storage medium.

Background technique

In the prior art, when a user equipment (UE) switches between different access points (APs) under the same Evolved Packet Data Gateway (ePDG), the UE switches from AP1 to AP2. The UE only needs to send a MOBIKE (IKEv2Mobility and Multihoming Protocol) request to the ePDG, and the request carries the updated UE local address, and the UE can continue to use the original IPsec (Internet Protocol Security Internet) tunnel to transmit data to ensure the UE's service. Not interrupted.

However, when AP1 and AP2 are connected to different ePDGs, for example, AP1 accesses S-ePDG (Source ePDG), and AP2 accesses T-ePDG (Target ePDG). When the UE moves from AP1 to AP2, because there is no UE information on the T-ePDG, the handover process can only be processed according to the initial attach procedure: the UE selects authentication, authorization, and accounting (Authentication, Authorization, Accountding, AAA) for authentication. After the completion of the right, the PDN gateway (PGW) is selected, but the PGW cannot be guaranteed to be selected. Even if the PGW originally accessed is selected, it cannot be associated with the previous session, and the PGW will re-send. The UE allocates an address and establishes a new IPsec tunnel.

It can be seen that after the UE crosses the ePDG, the user cannot be associated with the original session because there is no user information on the T-ePDG. Therefore, the PGW will re-assign the address to the UE and re-establish the IPsec tunnel and the GTP (GPRS Tunnel Protocol) tunnel. The ongoing business will definitely be interrupted, reconnecting the service will increase the time spent on information interaction, increase the network burden, and may lead to business. An error occurred.

Summary of the invention

In the prior art, after the UE crosses the ePDG, the ongoing service of the UE is sure to be interrupted, and the reconnection of the service increases the time occupied by the information interaction, increases the network burden, and may also cause a service error. To provide a packet data gateway, a method and system for switching across packet data gateways, and a computer storage medium that overcome the above problems or at least partially solve the above problems.

The embodiment of the invention provides a handover method for a cross-packet data gateway, including:

When the terminal moves from the first access point to the second access point, the second packet data gateway to which the second access point belongs receives the message from the terminal, where the message includes the address of the first packet data gateway to which the first access point belongs. ;

The second packet data gateway acquires parameter information of the first packet data gateway according to the first packet data gateway address, where the parameter information includes a public data network gateway address of the access terminal, and an IPsec tunnel of the IPsec tunnel connecting the terminal and the first packet data gateway. Identifying and connecting the GTP tunnel identifier of the GTP tunnel of the first packet data gateway and the public data network gateway;

The second packet data gateway establishes a connection with the terminal according to the parameter information;

The second packet data gateway establishes a connection with the public data network gateway according to the parameter information.

The processing of establishing a connection with the terminal by the second packet data gateway according to the parameter information includes:

The second packet data gateway establishes a connection with the terminal through the IPsec tunnel according to the IPsec tunnel identity.

The processing of establishing a connection with the public data network gateway according to the parameter information by the second packet data gateway includes:

The second packet data gateway establishes a connection with the public data network gateway through the GTP tunnel according to the GTP tunnel identifier and the public data network gateway address.

In the foregoing solution, after the second packet data gateway establishes a connection with the public data network gateway, the method further includes:

The second packet data gateway establishes a connection between the terminal and the public data network gateway.

The embodiment of the present invention further provides a handover system for a cross-packet data gateway, including a terminal, a first packet data gateway, a second packet data gateway, and a public data network gateway, where

The terminal, configured to: when moving from the first access point to the second access point, send a message to the second packet data gateway to which the second access point belongs, where the message includes the first packet data gateway to which the first access point belongs address;

a second packet data gateway, configured to receive a message from the terminal, where the message includes an address of the first packet data gateway to which the first access point belongs, and obtain parameter information of the first packet data gateway according to the address, where the parameter information includes the access terminal a public data network gateway address, an IPsec tunnel identifier of the IPsec tunnel connecting the terminal and the first packet data gateway, a GTP tunnel identifier of the GTP tunnel connecting the first packet data gateway and the public data network gateway, and respectively according to the parameter information, The public data network gateway establishes a connection.

A public data network gateway configured to establish a connection with the terminal through the second packet data gateway.

In the above solution, the system further includes:

a first packet data gateway interface, configured on the first packet data gateway, configured to perform message interaction with the second packet data gateway;

The second packet data gateway interface is disposed on the second packet data gateway and configured to perform message interaction with the first packet data gateway.

The embodiment of the invention further provides a packet data gateway, including:

a receiving module, configured to: when the terminal moves from the first access point to the second access point, receive a message from the terminal, where the message includes an address of the first packet data gateway to which the first access point belongs;

The obtaining module is configured to obtain parameter information of the first packet data gateway according to the first packet data gateway address, where the parameter information includes a public data network gateway address of the access terminal, and an IPsec tunnel of the IPsec tunnel connecting the terminal and the first packet data gateway Identifying and connecting the GTP tunnel identifier of the GTP tunnel of the first packet data gateway and the public data network gateway;

a first establishing module configured to establish a connection with the terminal according to the parameter information;

The second establishing module establishes a connection with the public data network gateway according to the parameter information.

The first establishing module is specifically configured to establish a connection with the terminal through the IPsec tunnel according to the IPsec tunnel identifier.

The second establishing module is specifically configured to establish a connection with the public data network gateway through the GTP tunnel according to the GTP tunnel identifier and the public data network gateway address.

In the above solution, the packet data gateway further includes:

A packet data gateway interface configured to interact with a message of the first packet data gateway.

The receiving module, the obtaining module, the first establishing module, and the second establishing module adopt a central processing unit (CPU) and a digital signal processor (DSP, Digital Singnal Processor) when performing processing. ) or programmable logic array (FPGA, Field-Programmable Gate Array) implementation.

The embodiment of the invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are configured to perform the switching method of the cross-packet data gateway.

The beneficial effects of the embodiments of the present invention are as follows:

With the terminal of the embodiment of the present invention, after the UE crosses the ePDG in the prior art, the ongoing service of the UE is sure to be interrupted, which greatly affects the convenience and practicability of the user to use the mobile phone, and cannot meet the user's needs. The problem of the user experience is reduced. With the present invention, the UE does not need to re-establish the IPsec tunnel and the GTP tunnel after the ePDG handover, the ongoing service of the UE is not interrupted, the network burden is reduced, the service time is reduced, and the service is guaranteed to be normal. The user's convenience and practicability of using the mobile phone is improved, and the user experience is improved.

The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below.

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the drawing:

1 is a flowchart of a method for switching a cross-packet data gateway according to an embodiment of the present invention;

2 is a flowchart of detailed processing of a method for switching a cross-packet data gateway according to an embodiment of the present invention;

3 is a schematic structural diagram of a handover system of a cross-packet data gateway according to an embodiment of the present invention;

4 is a schematic structural diagram of a handover system of a cross-packet data gateway according to an embodiment of the present invention;

5 is a flowchart of detailed processing of a handover method of a cross-packet data gateway according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a packet data gateway according to an embodiment of the present invention.

detailed description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the embodiments of the present invention have been shown in the drawings, the embodiments Rather, these embodiments are provided so that this disclosure will be more fully understood and the scope of the disclosure will be fully disclosed.

In the application scenario of the embodiment, the switching system of the embodiment of the present invention is applied to the VoWIFI, and the terminal, the WIFI device, and the packet data gateway are involved in the application scenario. The address of the first packet data gateway may be saved in the memory of the terminal, and the address of the first packet data gateway is sent to the second packet data gateway by the transmitter. The transmitter of the WIFI device is used to implement message transmission. The transmitter of the packet data gateway is used to implement information transmission and reception, and the processor keeps the processing result in the memory after analyzing and processing the information.

The invention will be further described in detail below with reference to the drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

First embodiment

According to an embodiment of the present invention, a method for switching across a packet data gateway is provided. FIG. 1 is a flowchart of a method for switching a cross-packet data gateway according to an embodiment of the present invention, including the following processing:

Step 101: When the terminal moves from the first access point to the second access point, the second packet data gateway to which the second access point belongs receives the message from the terminal, where the message includes the first packet data to which the first access point belongs. The address of the gateway;

Step 102: The second packet data gateway acquires parameter information of the first packet data gateway according to the first packet data gateway address, where the parameter information includes a public data network gateway address of the access terminal, an IPsec tunnel connecting the terminal and the first packet data gateway. The IPsec tunnel identifier, the GTP tunnel identifier of the GTP tunnel connecting the first packet data gateway and the public data network gateway;

Step 103: The second packet data gateway establishes a connection with the terminal according to the parameter information. Specifically, the second packet data gateway establishes a connection with the terminal through the IPsec tunnel according to the IPsec tunnel identifier.

Step 104: The second packet data gateway establishes a connection with the public data network gateway according to the parameter information. Specifically, the second packet data gateway establishes a connection with the public data network gateway through the GTP tunnel according to the GTP tunnel identifier and the public data network gateway address.

After step 104, the second packet data gateway establishes a connection between the terminal and the public data network gateway. At this time, the terminal has accessed the public data network gateway through the second packet data gateway, and the terminal and the public data network gateway can pass through. The second packet data gateway forwards the data.

2 is a detailed processing flowchart of a method for switching a cross-packet data gateway according to an embodiment of the present invention. As shown in FIG. 2, the following specifically includes the following processing:

Step 201: The UE moves from AP1 (ie, the first access point described above) to AP2 (ie, the second access point described above), and after connecting AP2, to the T-ePDG (ie, as described above) The second packet data gateway) sends an IKE_SA_INIT message to negotiate to establish an IKE SA, in the process, The UE and the T-ePDG negotiate an encryption algorithm.

Step 202: The UE sends a MOBIKE request to the T-ePDG, and adds an S-ePDG (ie, the first packet data gateway) address in the signaling.

Step 203: After receiving the MOBIKE request, the T-ePDG obtains the session authentication information, the accessed PGW (that is, the public data network gateway address) address, the established IPsec tunnel, the GTP tunnel, and the like to the S-ePDG. .

Step 204: The T-ePDG sends a MOBIKE response to the UE, and the T-ePDG can use the IPsec tunnel established by the previous S-ePDG.

Step 205: The T-ePDG directly initiates an update bearer request to the PGW according to the previously obtained PGW address.

Step 206: The PGW associates the original session and returns an update bearer response to the T-ePDG.

Step 207, at this time, the UE has accessed the PGW through the T-ePDG, and can forward data through the T-ePDG.

Step 208: The PGW initiates a release session process to the S-ePDG.

With the method of the present invention, after the UE crosses the ePDG, the selected PGW is the same, and the PGW does not need to re-allocate the address to the UE, and continues to use the originally established IPsec tunnel and the GTP tunnel, and the service is not interrupted. The small network burden, reducing the time-consuming business, ensuring the normal operation of the business, improving the convenience and practicability of the user to use the mobile phone, and improving the user experience.

Second embodiment

According to an embodiment of the present invention, a handover system is provided across a packet data gateway, and FIG. 3 is a schematic structural diagram of a handover system of a cross-packet data gateway according to an embodiment of the present invention, including: a terminal 30, a first packet data gateway 32, The second packet data gateway 34 and the public data network gateway 36 are described in detail below for each module of the embodiment of the present invention.

The terminal 30 is configured to, when moving from the first access point to the second access point, send a message to the second packet data gateway 34 to which the second access point belongs, where the message includes the first packet to which the first access point belongs. The address of the data gateway 32;

The second packet data gateway 34 is configured to receive a message from the terminal 30, where the message includes an address of the first packet data gateway 32 to which the first access point belongs, and obtain parameter information of the first packet data gateway 32 according to the address, where the parameter information includes The public data network gateway 36 address of the access terminal 30, the IPsec tunnel identifier of the IPsec tunnel connecting the terminal 30 with the first packet data gateway 32, and the GTP tunnel identifier of the GTP tunnel connecting the first packet data gateway 32 and the public data network gateway 36 And establishing a connection with the terminal 30 and the public data network gateway 36 according to the parameter information.

The public data network gateway 36 is configured to establish a connection with the terminal 30 via the second packet data gateway 34.

Wherein, the system may further comprise:

a first packet data gateway interface, disposed on the first packet data gateway 32, configured to perform message interaction with the second packet data gateway 34;

The second packet data gateway interface, disposed on the second packet data gateway 34, is configured to interact with the first packet data gateway 32 for messages.

4 is a schematic structural diagram of a handover system of a cross-packet data gateway according to an embodiment of the present invention, including the following devices: UE, AP1, AP2, S-ePDG, T-ePDG, and PGW. Both the S-ePDG and the T-ePDG are connected to the PGW through the S2b; the AP1 is connected to the S-ePDG, and the AP2 is connected to the T-ePDG. The S-ePDG and the T-ePDG have no interface, and the H1/H2 interface is added. The ePDG supports the H1/H2 interface. interface. The device UE and the ePDG support the extended MOBIKE request, and perform signaling interaction between the T-ePDG and the S-ePDG. The IPsec tunnel and the GTP tunnel established by the original S-ePDG can continue to be used between the UE, the PGW, and the T-ePDG.

With the present invention, after the UE is switched over the ePDG, the IPsec tunnel and the GTP tunnel need not be re-established, the ongoing service of the UE is not interrupted, the network burden is reduced, the service time is reduced, the service is guaranteed to be normal, and the mobile phone is used by the user. Convenience and practicality enhance the user experience.

The implementation of the cross-ePDG switching method of the present invention is further combined with the system structure of FIG. Detailed description of one step, FIG. 5 is a detailed processing flowchart of a method for switching a cross-packet data gateway according to an embodiment of the present invention. As shown in FIG. 5, the following specifically includes the following processing:

In step 501, the UE connects to AP1 and has accessed the PGW through the S-ePDG.

In step 502, the UE connects to AP2.

In step 503, the IKEv2 protocol consists of two phases of interaction. The first phase is called the IKE_SA_INIT exchange phase. The UE initiates a dynamic key agreement initialization (IKE_SA_INIT) message to the T-ePDG to negotiate to establish an IKE SA. In this process, the UE and the ePDG negotiate an encryption algorithm.

Step 504, the Mobility and Multihoming Protocol (MOBIKE) protocol is applied in a 3GPP-WLAN Interworking handover scenario. The UE sends a MOBIKE request to the T-ePDG, and is extended to increase the carrying S-ePDG address information. For example, the definition notification message type SOURCE_EPDG_ADDRESSES 16403 is added based on the RFC4555 protocol, and the content is a 4-byte S-ePDG IPV4 address. Or the IP address of the 16-byte S-ePDG.

In step 505, an H1/H2 interface is added between the ePDGs. The T-ePDG requests the S-ePDG for authentication information of the session, the accessed PGW address, the established IPsec tunnel, and the GTP tunnel.

In step 506, the S-ePDG returns the above information to the T-ePDG.

In step 507, the T-ePDG sends a MOBIKE response.

In step 508, the T-ePDG and the UE perform MOBIKE address verification.

In step 509, the T-ePDG directly initiates a Modify Bearer request according to the previously obtained PGW address.

In step 510, the PGW associates with the original session and returns a Modify Bearer response.

Step 511, if there is a PCRF, the PGW initiates an IP-CAN notification PCRF to modify the session information.

Step 512, at this time, the UE has accessed the PGW through the T-ePDG, and can forward data through the T-ePDG, and then the PGW initiates a release session flow to the S-ePDG.

In step 513, the PGW initiates a Delete Bearer request to the S-ePDG.

In step 514, the S-ePDG sends a deletion session (INFORMATIONAL) request to the UE.

In step 515, the UE sends a deletion session (INFORMATIONAL) response to the S-ePDG.

In step 516, the S-ePDG sends a Delete Bearer response to the PGW.

Third embodiment

FIG. 6 is a schematic structural diagram of a packet data gateway according to an embodiment of the present invention, including: a receiving module 60, an obtaining module 62, a first establishing module 64, and a second establishing module. 66. Each module of the embodiment of the present invention will be described in detail below.

The receiving module 60 is configured to receive, when the terminal moves from the first access point to the second access point, a message from the terminal, where the message includes an address of the first packet data gateway to which the first access point belongs;

The obtaining module 62 is configured to obtain parameter information of the first packet data gateway according to the first packet data gateway address, where the parameter information includes a public data network gateway address of the access terminal, and an IPsec of the IPsec tunnel connecting the terminal and the first packet data gateway. a tunnel identifier, a GTP tunnel identifier of a GTP tunnel connecting the first packet data gateway and the public data network gateway;

The first establishing module 64 is configured to establish a connection with the terminal according to the parameter information, where the first establishing module is specifically configured to establish a connection with the terminal through the IPsec tunnel according to the IPsec tunnel identifier;

The second establishing module 66 is configured to establish a connection by the public data network gateway according to the parameter information, and the second establishing module is specifically configured to establish a connection with the public data network gateway through the GTP tunnel according to the GTP tunnel identifier and the public data network gateway address.

The packet data gateway also includes:

An embodiment of the present invention further provides a computer storage medium, where the computer storage medium is stored Computer executable instructions are stored that are configured to perform the above-described method of switching across packet data gateways.

With the method, the device and the system of the present invention, after the UE is switched over the ePDG, the selected PGW is the same as the prior art, and the PGW does not need to re-allocate the address to the UE, and continues to use the originally established IPsec tunnel and the GTP tunnel to ensure The service is not interrupted, the network burden is reduced, the service is time-consuming, the service is guaranteed to be normal, the convenience and practicability of the user to use the mobile phone are improved, and the user experience is improved.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general purpose systems can also be used with the teaching based on the teachings herein. The structure required to construct such a system is apparent from the above description. Moreover, the invention is not directed to any particular programming language. It is to be understood that the invention may be embodied in a variety of programming language, and the description of the specific language has been described above in order to disclose the preferred embodiments of the invention.

In the description provided herein, numerous specific details are set forth. However, it is understood that the embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of the description.

Similarly, the various features of the invention are sometimes grouped together into a single embodiment, in the above description of the exemplary embodiments of the invention, Figure, or a description of it. However, the method disclosed is not to be interpreted as reflecting the intention that the claimed invention requires more features than those recited in the claims. More precisely, as claimed It is reflected that the inventive aspects are less than all of the features of the single embodiments disclosed above. Therefore, the claims following the specific embodiments are hereby explicitly incorporated into the embodiments, and each of the claims as a separate embodiment of the invention.

Those skilled in the art will appreciate that the modules in the client in the embodiment can be adaptively changed and placed in one or more clients different from the embodiment. The modules in the embodiments can be combined into one module, and further they can be divided into a plurality of sub-modules or sub-units or sub-components. In addition to such features and/or at least some of the processes or units being mutually exclusive, any combination of the features disclosed in the specification, including the accompanying claims, the abstract and the drawings, and any methods so disclosed, or All processes or units of the client are combined. Each feature disclosed in this specification (including the accompanying claims, the abstract and the drawings) may be replaced by alternative features that provide the same, equivalent or similar purpose.

In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features that are included in other embodiments and not in other features, combinations of features of different embodiments are intended to be within the scope of the present invention. Different embodiments are formed and formed. For example, in the following claims, any one of the claimed embodiments can be used in any combination.

The various component embodiments of the present invention may be implemented in hardware, or in a software module running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functionality of some or all of the components loaded with the ordered web address in accordance with an embodiment of the present invention. . The invention can also be implemented as a device or device program (e.g., a computer program and a computer program product) for performing some or all of the methods described herein. Such a program implementing the invention may be stored on a computer readable medium or may be in the form of one or more signals. Such signals can be downloaded from the Internet website, or Provided on the carrier signal or provided in any other form.

It is to be noted that the above-described embodiments are illustrative of the invention and are not intended to be limiting, and that the invention may be devised without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as a limitation. The word "comprising" does not exclude the presence of the elements or steps that are not recited in the claims. The word "a" or "an" The invention can be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means can be embodied by the same hardware item. The use of the words first, second, and third does not indicate any order. These words can be interpreted as names.

Industrial applicability

The terminal in the embodiment of the present invention solves the problem that the ongoing service of the UE is interrupted after the UE crosses the ePDG in the prior art, and the convenience and practicability of the user using the mobile phone are largely affected, and the user needs cannot be met. The problem of the user experience is reduced. After the UE is switched over the ePDG, the UE does not need to re-establish the IPsec tunnel and the GTP tunnel, and the ongoing service of the UE is not interrupted, the network burden is reduced, the service is time-consuming, and the service is guaranteed. The user's convenience and practicability of using the mobile phone is improved, and the user experience is improved.

Claims

A method for switching across packet data gateways includes:

When the terminal moves from the first access point to the second access point, the second packet data gateway to which the second access point belongs receives the message from the terminal, where the message includes the first access point attribution The address of the first packet data gateway;

And obtaining, by the second packet data gateway, session-related parameter information saved on the first packet data gateway according to the first packet data gateway address;

The second packet data gateway establishes a connection with the terminal according to the parameter information;

The second packet data gateway establishes a connection with the public data network gateway according to the parameter information.
The method of claim 1, wherein the parameter information comprises a public data network gateway address accessing the terminal, an IP security protocol tunnel connecting the terminal and an IP security protocol tunnel of the first packet data gateway And identifying a general packet radio service tunnel identifier of the general packet radio service tunnel of the first packet data gateway and the public data network gateway.
The method of claim 2, wherein the processing of establishing a connection with the terminal by the second packet data gateway according to the parameter information comprises:

And the second packet data gateway establishes a connection with the terminal by using the IP security protocol tunnel according to the IP security protocol tunnel identifier.
The method of claim 2, wherein the processing by the second packet data gateway to establish a connection with the public data network gateway according to the parameter information comprises:

And the second packet data gateway establishes a connection with the public data network gateway through the general packet radio service tunnel according to the general packet radio service tunnel identifier and the public data network gateway address.
A switching system for a cross-packet data gateway includes a terminal, a first packet data gateway, a second packet data gateway, and a public data network gateway, where

The terminal, configured to send a message to the second packet data gateway to which the second access point belongs, when the mobile device moves from the first access point to the second access point, where the message includes the first access point The address of the first packet data gateway;

a second packet data gateway, configured to receive a message from the terminal, where the message includes an address of a first packet data gateway to which the first access point belongs, and obtain the first packet data gateway according to the address Parameter information, and establishing a connection with the terminal and the public data network gateway according to the parameter information.

A public data network gateway configured to establish a connection with the terminal through the second packet data gateway.
The system of claim 5, wherein the parameter information comprises a public data network gateway address accessing the terminal, an IP security protocol tunnel connecting the terminal and an IP security protocol tunnel of the first packet data gateway And identifying a general packet radio service tunnel identifier of the general packet radio service tunnel of the first packet data gateway and the public data network gateway;
The system of claim 5 further comprising:

a first packet data gateway interface, configured on the first packet data gateway, configured to perform message interaction with the second packet data gateway;

The second packet data gateway interface is disposed on the second packet data gateway and configured to perform message interaction with the first packet data gateway.
A packet data gateway that includes:

a receiving module, configured to receive a message from the terminal when the terminal moves from the first access point to the second access point, where the message includes an address of the first packet data gateway to which the first access point belongs ;

An acquiring module, configured to acquire parameter information of the first packet data gateway according to the first packet data gateway address;

a first establishing module, configured to establish a connection with the terminal according to the parameter information;

The second establishing module establishes a connection with the public data network gateway according to the parameter information.

The parameter information includes a public data network gateway address that accesses the terminal, an IP security protocol tunnel identifier that connects the terminal with an IP security protocol tunnel of the first packet data gateway, and connects the first packet data gateway with a general packet radio service tunnel identifier of a general packet radio service tunnel of the public data network gateway;
The packet data gateway of claim 8 wherein

The first establishing module is configured to establish a connection with the terminal by using the IP security protocol tunnel according to the IP security protocol tunnel identifier.
The packet data gateway of claim 8 wherein

The second establishing module is configured to establish a connection with the public data network gateway through the general packet radio service tunnel according to the general packet radio service tunnel identifier and the public data network gateway address.
The packet data gateway according to any one of claims 7 to 10, further comprising:

And a packet data gateway interface configured to perform message interaction with the first packet data gateway.
A computer storage medium having stored therein computer executable instructions configured to perform the method of switching across packet data gateways of any of claims 1-5.