WO2008098510A1

WO2008098510A1 - Mehtod and apparatus for acquiring access controller information in wireless lan

Info

Publication number: WO2008098510A1
Application number: PCT/CN2008/070278
Authority: WO
Inventors: Chengping Ye; Changsheng Wan; Wei Yan
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-02-13
Filing date: 2008-02-04
Publication date: 2008-08-21
Also published as: CN101247295A

Abstract

A method and apparatus for acquiring access controller information in wireless LAN are provided which belong to the communication field. The method for acquiring access controller information in wireless LAN includes: AAA server receiving the message of requesting to certification which sent by WTP, certificating the WTP, sending a message of requesting for AC information to the AC information server after the certification is passed; AAA server acquiring AC information corresponding to WTP from the returning message of AC information server and sending the message including the AC information to the WTP which improve the possibility of acquiring the AC by WTP.

Description

Method and apparatus for obtaining access controller information in a wireless local area network

[1] Technical field

[2] The present invention relates to the field of communications, and more particularly to a method and apparatus for obtaining access controller information in a wireless local area network.

[3] Background of the invention

[4] WLAN (Wireless Local Area

Network, WLAN) by STA (Station, mobile) and AP (Access)

Point, access point) Composition: The physical layer of the STA is connected to the wireless medium; the AP is an entity capable of providing a delivery service for the STA. WLAN has two service sets: BSS (Basic Service

Set, basic service set) and ESS (Extended Service

Set, extended service set). The BSS consists of an AP and a STA associated with the AP. Usually, the scope covered by an AP is the basic service set. The association between the STA and the AP uses the basic service set identifier (BSSID). Generally, the AP's MAC address is used as the BSSID. An ESS is a structured network consisting of multiple APs and a distributed system connecting them. All APs must share the same Extended Service Set Identifier (ES SID), and an ESS can contain multiple BSSs.

[5] After the CAPWAP working group summarized the networking methods of WLANs of most companies in the world,

The networking and deployment of the AN is redefined. The CAPWAP working group divided the WLAN into an autonomous architecture and centralized structure (Centralized WLAN).

Architecture). Self-organizing structure is all WTP (Wireless Termination)

Point, Wireless Endpoint) Connected through a Layer 2 device, each WTP transmits data over Ethernet. The centralized structure is currently the most commonly used networking structure. As shown in Figure 1, in the centralized structure, WTP passes AC (Access).

Controller, access controller) Connect. In this networking mode, WTP can have one or more ACs. This networking method can separate data, control and management. For example, the control plane can be placed on the AC. In the centralized structure, it is divided into local MAC, split MAC, and remote MAC. Local The MAC fabric mode is a mode in which the access policy and management of the network is placed on the AC, and the 802.11 MAC function is placed on the WTP (including 802.11 management and control frames). Split

The MAC structure pattern is different from the local MAC structure, which is 802.11

The MAC function (including 802.11 management and control frames) is centralized on the AC, and the AC provides management and monitoring services for the WTP. The WTP only provides services for some real services. Remote

The MAC structure mode is that WTP only provides the physical layer function, and all other functions are concentrated on the AC. In this way, the burden of WTP is the lightest.

[6] WTP can obtain the address of the AC through static configuration, but this method is not easy to manage and control.

If the current AC is not available, WTP must get a new available AC, so the static configuration method may not work very well. In addition, WTP can also obtain the address of the AC through the CAPWAP protocol. For example, the WTP sends a discovery request message, and the AC that receives the message returns a discovery response to the WTP. However, the obvious shortcoming of this method is that it is not convenient for centralized management of AC itself.

[7] Summary of the invention

[8] The embodiment of the present invention provides a method for obtaining access controller information in a wireless local area network, where the method includes

[9] The authentication, authorization, and account AAA server receives the message of the request authentication sent by the WTP, and authenticates the WTP. After the authentication is passed, the message that the AC information is requested is sent to the access controller AC information server; [10] The AAA server obtains AC information suitable for the WTP from a message returned by the AC information server, and sends a message containing the AC information to the WTP.

[11] The embodiment of the present invention further provides a method for obtaining access controller information in a wireless local area network, including: [12] The AAA server receives a message sent by the standby AC to verify the WTP, and the request is verified by the WTP. The message is: the standby AC receives the message sent by the WTP transmission after the request to establish a connection with the standby AC;

[13] After the AAA server passes the verification of the WTP, it sends a message that the WTP authentication is passed to the standby AC, and after the standby AC receives the message that the WTP authentication passes, sends a response message to the WTP. .

[14] An embodiment of the present invention provides an apparatus for obtaining access controller information in a wireless local area network, where the apparatus includes: [15] an authentication module, configured to: after receiving the message requesting authentication sent by the WTP, authenticating the WTP, and outputting the authentication result;

[16] The AC selection module is configured to: after the authentication module passes the WTP authentication, obtain AC information suitable for the WTP from the AC information server, and send the AC information to the WTP.

An embodiment of the present invention provides an AAA server, where the AAA server includes an apparatus for obtaining access controller information in a wireless local area network, where the apparatus includes:

[18] an authentication module, configured to: after receiving the message requesting authentication sent by the WTP, authenticating the WTP, and outputting the authentication result;

[19] The AC selection module is configured to: after the authentication module passes the WTP authentication, obtain AC information suitable for the WTP from the AC information server, and send the AC information to the WTP.

[20] The embodiment of the present invention provides a network for obtaining access controller information, where the network includes: [21] a wireless termination point, configured to send a message requesting authentication;

[22] The AAA server is configured to: after receiving the message sent by the wireless endpoint, authenticate the wireless termination point, and send a message requesting access to the controller information after the authentication is passed;

[23] The access controller information server is configured to: after receiving the message sent by the AAA server, select an access controller information that is suitable for the wireless termination point, and pass the access controller information by using the The AAA server forwards to the wireless endpoint.

[24] The embodiment of the present invention further provides an apparatus for obtaining access controller information in a wireless local area network, including: [25] a selecting module for selecting a standby AC;

[26] The verification module is configured to: after receiving the message that the request sent by the WTP is connected to the standby AC selected by the selecting module, verify the WTP, and send the verification result to the establishing module;

[27] The establishing module is configured to establish a connection between the standby AC selected by the selecting module and the WTP after the verification module passes the WTP verification.

An embodiment of the present invention further provides an AAA server, where the AAA server includes an apparatus for obtaining access controller information in a wireless local area network, where the apparatus includes:

[29] The selection module is used to select an alternate AC;

[30] The verification module is configured to: after receiving the message that the request sent by the WTP is connected to the standby AC selected by the selecting module, verify the WTP, and send the verification result to the establishing module; [31] The establishing module is configured to establish a connection between the standby AC selected by the selecting module and the WTP after the verification module passes the WTP verification.

[32] The embodiment of the present invention further provides a network for obtaining access controller information, where the network includes: [33] a wireless termination point, configured to send a message requesting authentication;

[34] an AAA server, configured to: after receiving the message sent by the wireless endpoint, authenticate the wireless endpoint, and send a message requesting access to the controller information after the authentication is passed;

[35] an access controller information server, configured to: after receiving the message sent by the AAA server, select an access controller information that is suitable for the wireless termination point, and pass the access controller information by using the The AAA server forwards to the wireless endpoint.

[36] An embodiment of the present invention further provides an apparatus for obtaining access controller information in a wireless local area network, where the apparatus includes:

[37] Select module for selecting an alternate AC;

[38] the verification module is configured to: after receiving the message that the request sent by the WTP is connected to the standby AC selected by the selecting module, verify the WTP, and send the verification result to the establishing module;

[39] The establishing module is configured to establish a connection between the standby AC selected by the selecting module and the WTP after the verification module passes the WTP verification.

An embodiment of the present invention further provides an AAA server, where the AAA server includes:

[41] The verification module is configured to: after the WTP request establishes a connection with the standby AC, verify the WTP, and send a verification result to the standby AC, where the verification result is used to determine whether between the WTP and the standby AC. establish connection.

[42] The embodiment of the present invention provides a method for obtaining AC information by using the AAA server and the AC information server, and solves the problem that the WTP cannot establish a connection with the AC because the AC information cannot be obtained.

[43] BRIEF DESCRIPTION OF THE DRAWINGS

[44] FIG. 1 is a schematic diagram of a WLAN networking with a centralized structure;

2 is a flowchart of a method for obtaining access controller information when the WTP is first started in the embodiment of the present invention. [46] FIG. 3 is an embodiment of the present invention, when the WTP is started for the first time, access control is obtained. Message flow chart 4 is a flow chart of a method for enabling a standby AC when the WTP and the current AC are disconnected according to an embodiment of the present invention;

5 is a message flow diagram of enabling an alternate AC when the WTP and the current AC are disconnected according to an embodiment of the present invention;

6 is a structural diagram of an apparatus for obtaining access controller information in a wireless local area network according to an embodiment of the present invention;

7 is a structural diagram of an AAA server having the function of obtaining access controller information according to an embodiment of the present invention;

FIG. 8 is a structural diagram of a network for obtaining access controller information according to an embodiment of the present invention; FIG.

9 is a structural diagram of another apparatus for obtaining access controller information in a wireless local area network according to an embodiment of the present invention;

FIG. 10 is a structural diagram of another AAA server having the function of obtaining access controller information according to an embodiment of the present invention; FIG.

11 is a structural diagram of another network for obtaining access controller information according to an embodiment of the present invention.

[55] Mode for carrying out the invention

[56] The embodiment of the present invention proposes a WTP using AAA (Authentication, Authorization and Accounting) protocol and ACIS (AC Information).

Server, AC Information Server) A method of obtaining and authenticating AC information. When the WTP is started for the first time, or when the WTP and the current AC are interrupted, the AC information can be obtained using the method proposed by the embodiment of the present invention.

[When the WTP is started for the first time, the WTP sends a message requesting authentication to the AAA server. After receiving the message sent by the WTP, the AAA server authenticates the WTP. After the authentication is passed, the message sends the request AC information to the ACIS. The AAA server obtains AC information suitable for WTP from the message returned by the ACIS, and sends a message containing the AC information to the WTP.

[58] 上述 Using the above technical solution WTP method for obtaining AC information specifically includes the following steps, see Figure 2 and Figure 3

[59] Step 101: The WTP sends an authentication request message to the AAA server.

[60] The authentication request message includes the WTP-ID encrypted with WTP-AAA_key, and also includes the WTP identifier (WT). MAC type (WTP MAC

Type). The WTP identifier is used to identify the WTP identity. This identifier is unique in a mobile domain. The discovery type is used to describe how to discover the WTP. The WTP descriptor is used to describe the status of the requesting AC. For example, the current WTP number of the AC connection, and the maximum connection WTP. Number; WTP

The MAC type indicates the type of MAC supported by WTP. For example, WTP supports split MAC, and local MAC supports both. WTP frame tunnel mode indicates the tunnel mode supported by WTP.

[61] Step 102: After receiving the authentication request message, the AAA server verifies the WTP-ID.

[62] The AAA server decrypts the encrypted WTP-ID obtained from the authentication request message with WTP-AAA_key, and compares the decrypted WTP-ID with the WTP-ID obtained from the authentication request message, if two If the WTP-ID is the same, step 104 is performed. If the two WTP-IDs are different, step 103 is performed.

[63] Step 103: The AAA server returns an error code to WTP.

[64] WTP received an error code and was notified that the authentication failed.

[65] Step 104: The AAA server sends an AC information request message to the ACIS.

[66] The AC information request message includes the WTP identifier (WTP-ID), the discovery type (Discovery)

Type), WTP Descriptor, WTP Frame Tunnel Mode

Mode), WTP MAC Type (WTP MAC Type).

[67] Step 105: The ACIS searches its own information table according to the WTP-ID, and returns the AC suitable for WTP request to the AAA server with an AC information reply message.

[68] The AC information response message includes a preferred AC, and may also include at least one standby AC, and each AC includes an AC descriptor (AC Descriptor) and an AC name (AC Name). The AC descriptor is used to indicate the status of the requesting AC, such as the current WTP number of the AC connection, and the maximum connection W.

TP number, etc.; AC Name is the identifier of an AC in a domain.

[69] Step 106: After receiving the AC information response message, the AAA server generates a random number for the preferred AC, and generates a WTP-AC_key by using the random number, and sends a first AC verification request message to the preferred AC.

[70] The AAA server uses the generated random number and the shared secret material generated between the WTP and the AAA server.

WTP-AC_key. The first AC check request message includes WTP-AC_key and the AC name obtained from the AC information reply message.

[71] Step 107: After receiving the first AC verification request message, the preferred AC checks the received AC and sends it to the AA. The A server sends a first AC check response message.

[72] The preferred AC compares the AC name obtained from the first AC check request message with its own AC name. If the two AC names are the same, the first AC check response message indicating that the preferred AC request is successful is sent to the AAA server. If the two AC names are different, send a first AC check response message indicating that the preferred AC request failed to the AAA server.

[73] Step 108: The AAA server receives the first AC check response message, and determines the content of the first AC check response message. If the first AC check response message indicates that the preferred AC request is successful, step 109 is performed, if the first AC check is performed. If the response message indicates that the preferred AC request fails, the AAA server selects the standby AC as the preferred AC, and step 106 is performed.

[74] Step 109: The AAA server sends an authentication response message to the WTP.

[75] The authentication response message sent by the AAA server includes the random number generated in step 106 and the preferred AC in step 108.

[76] Step 110: After receiving the authentication response message, the WTP calculates the WT according to the random number in the authentication response message.

P-AC_key, sends the first AC discovery request message to the preferred AC.

[77] The first AC discovery request message includes WTP-ID, WTP-ID, discovery type, encrypted with WTP-AC_key,

WTP descriptor, WTP frame tunnel mode, WTP MAC type.

[78] Step 111: After receiving the first AC discovery request message, the AC checks the WTP-ID and sends the first

The AC finds a response message to the WTP.

[79] Preferred WTP-AC obtained from the first AC check request message after the AC receives the first AC discovery request message.

_key decrypts the encrypted WTP-ID, and compares the decrypted WTP-ID with the WTP-ID obtained from the first AC discovery request message. If the two WTP-IDs are the same, the preferred AC sends a notification request to the WTP. The successful first AC discovery response message, if the two WTP-IDs are not the same, the preferred AC sends a first AC discovery response message indicating that the request failed to the WTP.

[00] Step 112: After receiving the first AC discovery response message, the WTP determines the content of the first AC discovery response message. If the WTP receives the first AC discovery response message indicating that the request is successful, the step S113 is performed, if the WTP receives the indication request. If the failed first AC discovery response message is sent, the WTP resends the authentication request message to the AAA server, and step 101 is performed.

[81] Step 113: WTP performs other CAPWAP operations. [82] In this embodiment, since the WTP obtains the AC information through the AAA server and the ACIS, the possibility that the WTP obtains the AC information is greatly improved, and the WTP can also implement the bootstrapping.

[83] In practical applications, WTP will be disconnected from the current AC for some reason, so WTP will activate the standby AC. In this case, the WTP selects a standby AC and sends a message to the standby AC to establish a connection with the standby AC. After receiving the message sent by the WTP, the standby AC sends a message requesting WTP authentication to the AAA server. After the WTP authentication is passed, the WTP authentication message is sent to the standby AC. After receiving the WTP authentication message, the standby AC sends a response message to the WTP.

[84] The process of WTP enabling alternate AC specifically includes the following steps, see Figure 4 and Figure 5:

[85] Step 201: The WTP generates a random number for the standby AC, and calculates the WTP-AC_key by using the random number and the shared secret material between the WTP and the AAA server.

[86] Step 202: The WTP sends the first AC Discovery Request message to the standby AC.

[87] The first AC discovery request message includes a WTP-ID encrypted with WTP-AAA_key, a WTP-ID encrypted with WTP-AC_key, a random number encrypted with WTP-AAA_key, and also includes a WTP-ID, a discovery type, and a WTP descriptor. , WTP frame tunnel mode, WTP

MAC type. The random number encrypted by WTP-AAA_key is the random number generated in step 201.

[88] Step 203: After receiving the first AC discovery request message, the standby AC sends a WTP authentication request message to the AAA server.

[89] WTP Authentication Request message includes WTP-ID encrypted with WTP-AAA_key

, random number encrypted with WTP-AAA_key and WTP-ID.

[90] Step 204: After receiving the WTP verification request message, the AAA server decrypts the random number sent by the WTP, and uses the random number to calculate the WTP-AC_key and sends the WT to the standby AC.

WTP verification confirmation message of P-AC_key.

[91] Step 205: After receiving the WTP verification confirmation message, the standby AC checks the WTP-ID and sends the first A.

C finds a reply message to WTP.

[92] After receiving the WTP verification confirmation message, the standby AC decrypts the encrypted WTP-ID with the WTP-AC_key obtained from the WTP verification confirmation message, and decrypts the decrypted WTP-ID with the first AC discovery request message. The obtained WTP-ID is compared. If the two WTP-IDs are the same, the standby AC sends a first AC discovery response message indicating that the request is successful to the WTP. If the two WTP-IDs are different, the standby AC sends the WTP to the WTP. Indicates the first AC discovery response message indicating that the request failed.

[00] Step 206: After receiving the first AC discovery response message, the WTP determines the content of the first AC discovery response message. If the WTP receives the first AC discovery response message indicating that the request is successful, step 207 is performed, if the WTP receives the indication request. If the failed first AC finds the response message, the WTP enables the other standby ACs, and step 201 is performed.

[94] When the WTP receives the first AC discovery response message indicating that the request failed, WTP can enable other alternate ACs if there are other alternate ACs available. In addition, WTP can be enabled for the first boot process.

[95] Step 207: WTP performs other CAPWAP operations.

[96] In this embodiment, the WTP obtains the AC information through the AAA server, so that when the WTP is disconnected from the current AC, the WTP can implement the connection between the WTP and the AC by starting the standby AC, thereby ensuring continuous communication. Sex.

[97] Referring to FIG. 6, an embodiment of the present invention provides a device for obtaining access controller information in a wireless local area network.

The device includes an authentication module and an AC selection module;

[98] The authentication module is configured to: after receiving the message requesting authentication sent by the WTP, authenticate the WTP, and send the authentication result to the AC selection module;

[99] The AC selection module is used to obtain the appropriate information from the AC information server after the authentication module passes the WTP authentication.

WTP AC information, and send the AC information.

[100] This embodiment obtains AC information through the authentication module and the AC selection module, which greatly improves W.

The possibility of TP obtaining AC information.

[007] Referring to FIG. 7, an embodiment of the present invention provides an AAA server, where the AAA server includes an apparatus for obtaining access controller information in a wireless local area network, where the apparatus includes an authentication module and an AC selection module.

[102] The authentication module is configured to: after receiving the message requesting authentication sent by the WTP, authenticate the WTP, and send the authentication result to the AC selection module;

[103] The AC selection module is used to obtain the appropriate information from the AC information server after the authentication module passes the WTP authentication.

WTP AC information, and send the AC information.

[104] In this embodiment, a device for obtaining access controller information in a wireless local area network is added to the AAA server, so that the AAA server not only has the functions of authentication, authorization, and account, but also provides a wireless termination point. For access to controller information.

[008] Referring to FIG. 8, an embodiment of the present invention provides a network for obtaining access controller information, where the network includes a wireless termination point, an AAA server, and an access controller information server.

[106] The wireless endpoint is used to send a message requesting authentication to the AAA server;

[107] After receiving the message sent by the wireless endpoint, the AAA server authenticates the wireless endpoint, and sends a message requesting access to the controller information to the access controller information server after the authentication is passed;

[108] After receiving the message sent by the AAA server, the access controller information server selects the access controller information suitable for the wireless endpoint, and forwards the access controller information to the wireless endpoint through the AAA server.

[109] In this embodiment, a wireless termination point provides a network for obtaining access controller information, and the wireless termination point of the network can obtain an access controller suitable for itself without an access controller being available. Information, thereby establishing a connection.

[110] Referring to FIG. 9, an embodiment of the present invention further provides an apparatus for obtaining access controller information in a wireless local area network, where the apparatus includes a selection module, a verification module, and an establishment module;

[111] The selection module is used to select an alternate AC;

[112] The verification module is configured to: after receiving the message that the request sent by the WTP is connected with the standby AC selected by the selection module, verify the WTP, and send the verification result to the establishing module;

[113] The setup module is used to select the alternate AC and WT selected in the module after the verification module passes the WTP verification.

A connection is established between P.

[114] In this embodiment, the standby AC is enabled by the selection module and the verification module, so that when the connection between the WTP and the current AC is interrupted, the connection between the WTP and the AC can be implemented by starting the standby AC, thereby ensuring continuity of communication. .

[115] Referring to FIG. 10, an embodiment of the present invention further provides an AAA server, where the AAA server includes means for obtaining access controller information in a wireless local area network, where the apparatus includes a verification module;

[116] After the selection module selects a standby AC, the verification module receives the message sent by the WTP and establishes a connection with the standby AC selected by the module, and then verifies the WTP, and sends the verification result to the establishment module;

[117] The setup module is used to select the alternate AC and WT selected in the module after the verification module passes the WTP verification. A connection is established between P.

[118] In this embodiment, a verification module is added to the AAA server, so that the AAA server not only has the verification.

, authorization and account functions, and can also provide access controller information for wireless endpoints.

[119] Referring to FIG. 11, an embodiment of the present invention further provides a network for obtaining access controller information, where the network includes a wireless termination point and an AAA server;

[120] The wireless endpoint is used to send a message to the AAA server requesting to establish a connection with the standby access controller; [121] the AAA server is configured to verify the wireless endpoint after receiving the message sent by the wireless endpoint, and After the verification is passed, the message that the verification is passed is sent to the wireless endpoint.

[122] In this embodiment, a wireless termination point provides a network for obtaining access controller information, and the wireless termination point of the network can obtain an access controller suitable for itself without an access controller being available. Information, thereby establishing a connection.

[123] Embodiments of the invention may be implemented in software, for example, utilized. Language programming such as C++ or JAVA, the corresponding software can be stored in a readable storage medium, such as a computer hard disk, memory.

The embodiments described above are only preferred embodiments of the present invention, and the usual variations and substitutions made by those skilled in the art within the scope of the technical solutions of the present invention are included in the scope of the present invention.

Claims

Claim

[1] A method for obtaining access controller information in a wireless local area network, the method comprising:

Authentication, authorization, and account The AAA server receives the request authentication message sent by the WTP, and authenticates the W TP. After the authentication is passed, the AAA server sends a message requesting the AC information to the access controller AC information server.

And the AAA server obtains A C information suitable for the WTP from a message returned by the AC information server, and sends a message containing the AC information to the WTP.

[2] The method for obtaining access controller information in a wireless local area network according to claim 1, wherein the AAA server receives the message requesting authentication sent by the WTP, and performs authentication on the WTP, after the authentication is passed. The sending the message requesting the AC information to the AC information server includes: obtaining, by the AAA server, a key, an encrypted W TP identifier, and an unencrypted WTP identifier from the message requesting the authentication sent by the WTP, and using the key pair The encrypted WTP identifier is decrypted, and the decrypted WTP identifier is compared with the unencrypted WTP identifier. If the two WTP identifiers are the same, the shell I" sends a message requesting AC information to the AC information server.

[3] The method for obtaining access controller information in a wireless local area network according to claim 1, wherein the AAA server obtains an AC suitable for the WT P from a message returned by the AC information server. And the sending, by the AAA server, the preferred AC information that is suitable for the WTP, and generating one for the preferred AC, by using the message returned by the AC information server. a random number, the key between the WT P and the preferred AC is generated by using the random number, and the message containing the key and the preferred AC information is sent to the preferred AC;

The preferred AC checks the received preferred AC information, and sends a response message to the AA A server after the verification is passed;

After receiving the response message, the AAA server sends a message containing the preferred AC information to the WTP.

[4] The method for obtaining access controller information in a wireless local area network according to claim 3, wherein the message returned by the AC information server further comprises: standby AC information; and an AAA server After receiving the response message of the verification failure returned by the preferred AC, select the standby AC as the preferred AC.

[5] The method for obtaining access controller information in a wireless local area network according to claim 3, wherein after receiving the response message, the AAA server sends the preferred AC to the WTP. The message of the message also includes:

After the WTP obtains the preferred AC information from the received message, the WTP sends a message including the WTP identifier and the encrypted WTP identifier to the preferred AC, where the preferred AC pair receives the WTP identifier. A check is performed to send a response message to the WTP.

[6] The method for obtaining access controller information in a wireless local area network according to claim 5, wherein the preferred AC checks the received WTP identifier, and sends a response to the WTP. The message specifically includes:

Decrypting the encrypted WTP identifier obtained from the message with the preferred AC key, and comparing the decrypted WTP identifier with the WTP identifier obtained from the message, if the two WTP identifiers are the same The preferred AC sends a message indicating that the request is successful to the WTP. If the two WTP identifiers are different, the preferred AC sends a message indicating that the request fails to the WTP.

[7] The method for obtaining access controller information in a wireless local area network according to claim 1, wherein the message containing the AC information sent to the WTP specifically includes: the AC descriptor and AC name, the AC descriptor includes the number of WTPs currently connected by the AC and the maximum number of connected WTPs.

[8] 8. A method for obtaining access controller information in a wireless local area network, wherein the method comprises:

The AAA server receives the message sent by the standby AC to verify the WTP, and the message that the request is authenticated to the WT P is: the message sent by the standby AC after receiving the message from the WTP transmission to establish a connection with the standby AC;

After the AAA server passes the verification of the WTP, the AAA server sends a message that the WTP authentication passes to the standby AC, and after the standby AC receives the message that the WTP authentication passes, sends a response message to the WTP.

[9] 9. The method for obtaining access controller information in a wireless local area network according to claim 8, wherein The method specifically includes:

The WTP selects a standby AC, generates a random number for the standby AC, encrypts the random number by using a key between the WTP and the AAA server, and sends the encrypted random number to the standby AC. The WTP identifier, the encrypted WTP identifier message, and the standby AC, after receiving the message sent by the WTP, sending the encrypted random number, the WTP identifier, and the encrypted WTP identifier to the AAA server. The AAA server decrypts the encrypted random number obtained from the message, calculates a key between the WTP and the standby AC by using the decrypted random number, and sends the key to the standby AC. Key message

The standby AC checks the WTP identifier with a key obtained from the message, and sends a response message to the WTP.

[10] The method for obtaining access controller information in a wireless local area network according to claim 9, wherein the standby AC checks the WTP identifier with a key obtained from the message, and Sending a response message to the WTP specifically includes:

The standby AC decrypts the encrypted WTP identifier by using a key obtained from the message, and compares the decrypted WTP identifier with the WTP identifier obtained from the request message. If the two W TP identifiers are the same, The standby AC sends a response message indicating that the request is successful to the WTP. If the two WTPs are different, the standby AC sends a response message indicating that the request fails to the WTP.

[11] 11. An apparatus for obtaining access controller information in a wireless local area network, wherein the apparatus comprises:

An authentication module, configured to: after receiving the message requesting authentication sent by the WTP, authenticating the WTP, and outputting the authentication result;

The AC selection module is configured to: after the authentication module passes the WTP authentication, obtain AC information suitable for the WTP from the AC information server, and send the AC information to the WTP.

[12] 12. An AAA server, wherein the AAA server includes means for obtaining access controller information in a wireless local area network, the device comprising:

An authentication module, configured to: after receiving the message requesting authentication sent by the WTP, identify the WTP Certificate, and output the certification result;

[13] 13. The network for obtaining access controller information, wherein the network comprises: a wireless termination point, configured to send a message requesting authentication;

An AAA server, configured to: after receiving the message sent by the wireless endpoint, authenticate the wireless endpoint, send a message requesting access to the controller information after the authentication is passed; and access the controller information server, where After receiving the message sent by the AAA server, the access controller information suitable for the wireless termination point is selected, and the access controller information is forwarded to the wireless termination point by using the AAA server.

[14] 14. An apparatus for obtaining access controller information in a wireless local area network, wherein the apparatus comprises:

a selection module for selecting an alternate AC;

a verification module, configured to: after receiving a message that the request sent by the WTP is connected to the standby AC selected by the selection module, verify the WTP, and send the verification result to the establishment module to be used in the After the verification module passes the verification of the WTP, a connection is established between the standby AC selected by the selection module and the WTP.

[15] 15. An AAA server, characterized in that the AAA server comprises:

And a verification module, configured to: after the WTP request establishes a connection with the standby AC, verify the WTP, and send a verification result to the standby AC, where the verification result is used to determine whether a connection is established between the WTP and the standby AC.