WO2018133334A1

WO2018133334A1 - L2tp-based wireless access system and interaction method therefor

Info

Publication number: WO2018133334A1
Application number: PCT/CN2017/091052
Authority: WO
Inventors: 夏亮; 朱丽娟
Original assignee: 深圳国人通信股份有限公司
Priority date: 2017-01-22
Filing date: 2017-06-30
Publication date: 2018-07-26
Also published as: CN106793013A

Abstract

The present invention relates to an L2TP-based wireless access system and an interaction method therefor. The interaction method comprises the following steps: a wireless access point joining a wireless access controller via the Internet; the wireless access controller issuing a wireless local area network configuration and an L2TP tunnelling configuration to the wireless access point; a wireless client going on-line and sending a data message to the wireless access point; the wireless access point encapsulating the data message and sending same to the wireless access controller; the wireless access controller de-encapsulating the encapsulated data message, and implementing layer two forwarding to send same to a broadband access server of an external network device; the broadband access server of the external network device replying a message of an Ethernet frame to the wireless access controller; the wireless access controller searching for a path of the wireless client through a port mapping table, and implementing L2TP layer two tunnelling encapsulation on the message and sending same to the wireless access point; and the wireless access point de-encapsulating the encapsulated message and forwarding same to the wireless client. The present invention uses an L2TP standard protocol to realise data interaction among STAs, APs, ACs, and BASs, and has a good compression and encryption performance and low costs.

Description

Title: L2TP-based wireless access system and its interaction method

[0001] The present invention relates to the field of wireless communications, and in particular, to L2TP (Layer 2 Tunneling)

Protocol, Layer 2 tunneling protocol) The wireless access system and its interaction method use L2TP to perform tunnel encapsulation and decapsulation interaction between data packets between the wireless access point and the radio access controller.

Background technique

[0002] Currently, the tunnel encapsulator of data packets between an AP (Wireless Access Point) and an AC (Radio Access Controller) adopts the CAPWAP (Control And Provisioning of Wireless Access Points Protocol Specification) protocol. With the rapid development of WLAN, more and more places have deployed wireless networks, and fat APs have been unable to meet the demand. Therefore, the AP+AC architecture has emerged. To manage multiple A Ps through the AC for control message management and data processing, a standard protocol is needed to implement AP and AC interworking. In order to resolve the tunneling protocol, the IETF established the CAPWAP Working Group in 2005 to standardize the tunneling agreement between AP and AC. Main functions of the CAPWAP protocol: The AP automatically discovers the AC, the AC authenticates the AP, the AP obtains the software image from the AC, and the AP obtains the initial and dynamic configuration from the AC. The system can support local data forwarding and centralized data forwarding.

[0003] The centralized data forwarding encapsulates the data packet of the STA by the AP and performs the forwarding processing by the AC, which reduces the burden on the AP and facilitates unified management of the AC.

[0004] Although CAPWAP is a standardized protocol, there is no standard code available in the LINUX kernel. It needs to be re-issued, re-editing the message format and message content, and the bursting difficulty is increased and the burst period is long. At present, all major domestic manufacturers have customized a set of private CAPWAP protocols. If devices need to be interconnected, they need to re-issue the kernel code.

[0005] Because of its complete protocol architecture and efficient processing mechanism, the CAPWAP protocol is mainly used in carrier-class A C devices, and the number of management APs can reach thousands.

[0006] Nowadays, with the proliferation of smart terminals and the rapid development of mobile Internet, WLAN networks are gradually miniaturized into small and medium-sized commercial enterprises, for example, department stores, hospitals, cafes, etc., the number of APs that may be required for each scene. Dozens or even one or two, then the demand for AC orders is greatly weakened, miniaturized A C is gradually welcomed by the market due to its affordable price, and it is also a new product developed by major manufacturers. However, if the miniaturized AC still uses the CAPWAP protocol in data forwarding with the AP, it will greatly increase the difficulty and length of the bursting, increase the equipment cost, and miss the market opportunity.

technical problem

Problem solution

Technical solution

[0007] The object of the present invention is to overcome the deficiencies of the above technologies, and provide a wireless access system based on L2TP and an interaction method thereof.

An aspect of the present invention provides an L2TP-based wireless access system interaction method, including the following steps: a wireless access point joins a wireless access controller through the Internet, and configures wireless access on the wireless access controller. The wireless local area network configuration of the point; the wireless access controller delivers the wireless local area network configuration and the L2TP tunnel configuration for the wireless access point, and the L2TP tunnel configuration includes the IP address of the wireless access point and the downlink interface of the wireless access controller. IP address, source port number of the wireless access point, and destination port number of the wireless access controller; the wireless client goes online, sends a data packet to the wireless access point to access the external network; the wireless access point will receive The data packet is converted into an Ethernet frame, and the L2TP tunnel is set up according to the WLAN configuration and the L2TP tunnel configuration, and the data packet is encapsulated and sent to the radio access controller; the radio access controller receives the encapsulation After the data packet, the transport port checks the destination port number of the encapsulated data packet, and learns the encapsulated datagram. The tunnel packet is unpacked, and the Layer 2 forwarding is sent to the broadband access server of the external network device; the broadband access server of the external network device replies to the Ethernet frame packet to the wireless access controller; The path of the wireless client is searched through the mapping table of the port, and the packet is encapsulated by the L2TP layer 2 tunnel and sent to the wireless access point. The wireless access point learns the source port number of the encapsulated packet. The encapsulated packet is a tunnel packet, and is unpacked and forwarded to the wireless client.

[0009] Further, before the wireless access controller sends the wireless local area network configuration and the tunnel configuration, the wireless access controller further includes the following steps: determining the forwarding of the service set identifier configuration of the wireless local area network of the wireless access point Type, the forwarding type includes centralized forwarding and local forwarding. If the service set identifier is configured with centralized forwarding, the wireless access controller sends a wireless local area network with a virtual local area network ID of 1-4096 to the wireless network. The access point, and the L2TP tunnel configuration is delivered at the same time, if the service set identifier is configured. The local forwarding is performed, and the WLAN configuration and the L2TP tunnel configuration are not required to be sent. The data packets sent by the subsequent wireless clients are directly processed by the wireless access point.

[0010] Further, before the establishing, by the wireless access point, the L2TP tunnel, the method further includes: detecting whether the data packet is sent to the wireless access point itself, and if yes, performing the internal Processing, if not, the wireless access point establishes an L2TP tunnel according to the WLAN configuration and the L2TP tunnel configuration to encapsulate the data packet.

[0011] Further, the step of the wireless access point joining the wireless access controller through the Internet includes: the wireless access controller pre-configuring information of the wireless access point, where the information includes version information and/or a MAC address; The wireless access point is successfully powered on and joins the wireless access controller.

[0012] Further, the radio access controller includes an uplink interface, a downlink interface, and a sub-interface corresponding to the virtual local area network interface that is internally divided by the radio access controller, where the sub-interface includes a downlink sub-interface, a bridge interface, and a processing port for connecting to the L2TP tunnel; the radio access controller forwards the data packet to the broadband access server of the external network device by using the uplink interface; and the radio access controller After the L2TP Layer 2 tunnel is encapsulated, the Ethernet frame is sent to the bridge interface and the downlink sub-interface, and then sent to the wireless access point. If the data packet is sent to the wireless access point itself, the The bridge interface is handled internally by the wireless access point.

[0013] Further, the source port number of the wireless access point is configured by the wireless access controller to send a wireless local area network to the wireless access point, and the database is generated from the wireless access point and imported into the wireless access controller. The ID number of the source port number obtained by adding 30000 to the ID number; the destination port number of the radio access controller is 5247.

[0014] A second aspect of the present invention provides an L2TP-based wireless access system, including a wireless access point and a wireless access controller; the wireless access point includes: a first receiving module, configured to receive a wireless connection The WLAN configuration and the L2TP tunnel configuration are sent to the controller; the second receiving module is connected to the wireless client, and is configured to receive the data packet sent by the wireless client to access the external network; the third receiving module is configured to Receiving a packet sent by the radio access controller for performing L2TP Layer 2 tunnel encapsulation; the first processing module is respectively connected to the first receiving module and the second receiving module, and configured to send data sent by the received wireless client The packet is converted into an Ethernet frame, and the L2TP tunnel is set up according to the WLAN configuration and the L2TP tunnel configuration, and the data packet is encapsulated and sent to the radio access controller; the second processing module, The third receiving module is connected to the source port number of the packet encapsulated in the L2TP layer 2 tunnel, and the encapsulated packet is a tunnel packet, and is unpacked and forwarded to the wireless client.

[0015] The radio access controller includes: a first sending module, connected to the first receiving module, configured to send a wireless local area network configuration and an L2TP tunnel configuration to a wireless access point; and a fourth receiving module, The first processing module is connected to receive the encapsulated data packet sent by the wireless access point; the fifth receiving module is connected to the broadband access server of the external network device, and is configured to receive the broadband access of the external network device. The packet of the Ethernet frame replied by the server; the third processing module is respectively connected to the broadband access server of the fourth receiving module and the external network device, and is configured to receive the encapsulated data packet sent by the wireless access point. Viewing, by the transport layer, the destination port number of the encapsulated data packet, and knowing that the encapsulated data packet is a tunnel packet, performing unpacking, and forwarding the data packet to the broadband of the external network device. a fourth processing module, configured to be connected to the fifth receiving module and the third receiving module, and configured to search for a path of the wireless client according to the mapping table of the port, The packet of the Ethernet frame replied by the broadband access server of the network device is encapsulated by the L2TP Layer 2 tunnel and sent to the wireless access point.

[0016] Further, the radio access controller further includes a determining module, configured to be connected to the first sending module, and configured to determine, if the forwarding type of the service set identifier configuration of the wireless local area network of the wireless access point, Forwarding types include centralized forwarding and local forwarding.

[0017] Further, the wireless access point further includes a detection module, which is respectively connected to the second receiving module and the first processing module, and is configured to detect whether a data packet sent by the wireless client is sent to the wireless access Point itself.

[0018] Further, the radio access controller further includes a configuration module, where the configuration module is configured to pre-configure information of the wireless access point, where the information includes version information and/or a MAC address; The point further includes an adding module, and is connected to the configuration module, and is configured to join the wireless access controller after the wireless access point is successfully powered on.

Advantageous effects of the invention

Beneficial effect

[0019] The present invention adopts the L2TP standard protocol to complete the encapsulation and decapsulation of the tunnel between the AP and the AC, and realizes data interaction between the STA, the AP, the AC, and the BAS, and the provided tunnel header compression can reduce the system's credit sales. Low difficulty, short cycle, good compression and encryption performance, low cost, compatible with equipment from different manufacturers, more suitable AC architecture for small commercialization.

Brief description of the drawing

DRAWINGS

1 is a schematic diagram of an L2TP-based wireless access system according to the present invention;

2 is a schematic flowchart of an interaction method of an L2TP-based wireless access system according to the present invention;

3 is a schematic diagram of interaction of an interaction method of the wireless access system shown in FIG. 2;

4 is a schematic diagram of interaction of internal ports of the radio access controller shown in FIG. 2.

Embodiments of the invention

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0025] Referring to FIG. 1, a wireless access system based on L2TP (Layer 2 Tunneling Protocol) includes a wireless access point 10 (Acess Point, AP for short), and a wireless connection. Into the controller 20 (Acess Controller, AC for short), the wireless client 30 (Station, referred to as: STA) and the broadband access server 40 of the external network device (Broadband Access)

Server, referred to as: BAS). The broadband access server 40, the wireless local area network, the virtual local area network, and the service set identifiers of the wireless access point 10, the wireless access controller 20, the wireless client 30, and the external network device are respectively referred to as AP, AC, STA, and BAS, respectively. , WLAN, VLAN, SSID to indicate.

The AP 10 includes: a first receiving module 11 configured to receive a WLAN configuration and an L2TP tunnel configuration delivered by the AC 20, and a second receiving module 12, configured to receive the data packet sent by the STA 30, The third receiving module 13 is configured to receive the packet sent by the AC 20 and perform the L2TP layer 2 tunnel encapsulation; the first processing module 14 is respectively connected to the first receiving module 11 and the second receiving module 12, The data packet sent by the received STA 30 is converted into an Ethernet frame, and the L2TP tunnel is set up according to the WLAN configuration and the L2TP tunnel configuration to encapsulate the data packet and sent to the AC 20; the second processing module 15 and the third receiving module The connection is used to check the source port number of the packet encapsulated in the L2TP Layer 2 tunnel. The encapsulated packet is a tunnel packet, and is unpacked and forwarded to the STA 30. The detection module (not shown) And being connected to the second receiving module 12 and the first processing module 14, respectively, for detecting whether the data packet sent by the STA 30 is sent to the AP 10 itself.

[0027] The AC 20 includes: a first sending module 21, connected to the first receiving module 11, configured to send a WLAN configuration And L2TP tunnel configuration to AP

The fourth receiving module 22 is connected to the first processing module 14 and configured to receive the encapsulated data packet sent by the AP 10. The fifth receiving module 23 is connected to the BAS 40 and configured to receive the Ethernet frame replied by the BAS 40. The third processing module 24 is connected to the fourth receiving module 22 and the BAS 40, and is configured to: after receiving the encapsulated data packet sent by the AP 10, view the encapsulated data packet to the transport layer. The port number is obtained, and the encapsulated data packet is a tunnel packet, and the data packet is unpacked, and the data packet is forwarded to the BAS 40. The fourth processing module 25 is respectively connected to the fifth receiving module 23 and the third receiving module 13. The connection is used to search the path of the STA 30 according to the mapping table of the port, and encapsulate the packet of the Ethernet frame replied by the BAS 40 into the L2TP Layer 2 tunnel and send it to the AP 10; the determining module (not shown), and the first The sending module 21 is connected to determine the forwarding type of the SSID configuration of the WLAN of the AP 10, and the forwarding type includes centralized forwarding and local forwarding.

[0028] In this embodiment, AC

The device further includes a configuration module (not shown), and the configuration module is configured to pre-configure the information of the AP 10, where the information includes version information or a MAC address, and may include other versions, a MAC address, and the like; The module is added to the module, and is connected to the configuration module, and is used to join the AC 20 after the AP 10 is successfully powered on.

[0029] Referring to FIG. 2 and FIG. 3, an interaction method based on the L2TP wireless access system provided by the present invention includes the following steps:

[0030] The Sl and the AP 10 join the AC 20 through the Internet, and configure the WLAN configuration of the AP 10 on the AC 20. The specific steps of the AP 10 to join the AC 20 through the Internet include: The AC 20 pre-configures the information of the AP 10, where the information includes version information or a MAC address. Of course, the information may also include other information such as version information and MAC address. 10 Powered on successfully to join AC 20.

[0031] The S2 and the AC 10 deliver the WLAN configuration and the L2TP tunnel configuration to the AP 20. The L2TP tunnel configuration includes the IP address of the AP 10 (Src-IP), the IP address of the downlink interface of the AC 20 (Dst-IP), the source port number of the AP 10 (Src-port), and the destination port number of the AC 20 (Dst- Port). Before the AC 20 delivers the WLAN configuration and the L2TP tunnel configuration, the AP 20 includes the following steps: determining the forwarding type of the SSID configuration of the WLAN of the AP 10, and the forwarding type includes centralized forwarding and local forwarding. If the SSID is configured with centralized forwarding, the AC is configured. 20 will send a WLAN configuration with a VLAN ID ranging from 1-4096 to the AP.

10, and send the L2TP tunnel configuration at the same time. If the SSID is configured with local forwarding, no WLAN configuration is required. After the L2TP tunnel is configured, the data packets sent by the subsequent STAs 30 are directly processed by the AP 10.

[0032] In this embodiment, the source port number (Src-port) of the AP 10 is the ID number generated by the AC 20 for the AP 10 to deliver the WLAN configuration, and the database 10 is imported into the AC 20 from the AP 10, and is added to the ID number. The source port number (Src-port) obtained by the above 30000, for example, the ID number is 10, and the source port number (Src-port) is 30010. Since the AP 10 imports the AC 20 database, the generated ID number is unique and not repeated, so that multiple APs are present.

10 Import the database of AC 20 separately, and the source port numbers of multiple APs 10 do not conflict. The destination port number (Dst-port) of the AC 20 is 5247.

[0033] S3, the STA 30 is online, and sends a data packet to the AP 10 to access the external network. In this embodiment, the data packet is a data packet of the 802.11 protocol.

[0034] S4. The AP 10 converts the received data packet into an Ethernet frame, and sets up an L2TP tunnel to encapsulate the data packet according to the WLAN configuration and the L2TP tunnel configuration, and sends the data packet to the AC 20. Before establishing the L2TP tunnel, the AP 10 further includes the following steps: detecting whether the data packet is sent to the AP 10 itself, and if yes, processing by the AP 10 internally; if not, the AP 10 is configured according to the WLAN configuration and the L2TP tunnel configuration. The L2TP tunnel encapsulates data packets.

[0035] After receiving the encapsulated data packet, the AC 20 checks the destination port number (Dst-port) of the encapsulated data packet to the transport layer, and learns that the encapsulated data packet is a tunnel packet and is unpacked. , and do a Layer 2 forwarding to B AS 40, with BAS

40 connected external network devices can perform services such as DHCP, RADIUS authentication and accounting, portal push, and web browsing.

[0036] S6. The BAS 40 replies to the message of the Ethernet frame to the AC 20.

[0037] S7. The AC 20 searches for the path of the STA 30 through the mapping table of the port, and encapsulates the packet into the L2TP Layer 2 tunnel and sends the packet to the AP 10.

[0038] S8. The AP 10, by looking at the source port number (Src-port) of the encapsulated packet, learns that the encapsulated packet is a tunnel packet, and is unpacked and forwarded to the STA 30.

Referring to FIG. 4, AC 20 includes an uplink interface (ethl) 18 and a downlink interface (ethO), AC.

20 Internally, according to the WLAN configuration with the VLAN ID number sent to the AP 10 by the AC 20, the VLAN interface is divided. Each VLAN interface is assigned with a set of sub-interfaces: a downlink sub-interface, a bridge interface, and a processing port for connecting to the L2TP tunnel. . The bridge interface is connected to the processing port, and the processing port utilizes the L2TP standard protocol. It is responsible for the encapsulation and decapsulation of the tunnel. The process of processing the data packet is as follows: If the data packet is sent to the AC 20, the data packet is forwarded to the bridge interface and directly processed by the AC 20 internal protocol; The data message is sent from STA 30 to B AS.

40, after decapsulation, it is sent to the uplink interface (ethl) 18; if the data is sent from the BAS 40 to the STA 30, it is encapsulated and forwarded to the bridge interface, and then forwarded by the bridge interface to the downlink sub-interface. In this embodiment, assuming that the VLAN interface number of the internal division of the AC 20 is X, the set of sub-interfaces corresponding to the VLAN interface are: a downlink sub-interface (ethO.X), a bridge interface (brX) 17, and a connection for L2TP. The processing port of the tunnel (12tpethO.X) 16. The AC 20 forwards the data packet to the BAS 40 via the uplink interface (ethl) 18. AC

The L2TP Layer 2 tunnel is encapsulated in the Ethernet frame and sent to the bridge interface (brX) 17. The downlink sub-interface (ethO.X) 19 is sent to the AP 10. If the test data packet is sent to the AP

10 itself, then the bridge interface (brX) 17 is handed over to the inside of the AP 10.

The above embodiments are merely illustrative of the preferred embodiments of the present invention, and the description of the present invention is not to be construed as limited. It should be noted that various modifications and improvements can be made by those skilled in the art without departing from the inventive concept, such as combining different features in the various embodiments, and the like. The scope of protection of the present invention.

Claims

Claim

[Claim 1] An L2TP-based wireless access system interaction method, comprising: the following steps:

The wireless access point joins the wireless access controller through the Internet, and configures the wireless local area network configuration of the wireless access point on the wireless access controller;

The wireless access controller delivers a wireless local area network configuration and an L2TP tunnel configuration for the wireless access point, where the L2TP tunnel configuration includes an IP address of the wireless access point, an IP address of a downlink interface of the wireless access controller, and wireless access. The source port number of the point and the destination port number of the wireless access controller;

The wireless client is online, and sends a data packet to the wireless access point to access the external network. The wireless access point converts the received data packet into an Ethernet frame, and establishes an L2TP according to the WLAN configuration and the L2TP tunnel configuration. The tunnel encapsulates the data packet and sends the data packet to the radio access controller.

After receiving the encapsulated data packet, the radio access controller checks the destination port number of the encapsulated data packet to the transport layer, and learns that the encapsulated data packet is a tunnel packet, and performs unpacking. And doing the Layer 2 forwarding to the broadband access server sent to the external network device;

The broadband access server of the external network device replies to the packet of the Ethernet frame to the wireless access controller; the wireless access controller searches the path of the wireless client through the mapping table of the port, and encapsulates the packet into the L2TP Layer 2 tunnel, and concurrently The wireless access point is configured to view the encapsulated packet as a tunnel packet, and then unpack the packet and forward it to the wireless client.

[Claim 2] The interaction method of the L2TP-based wireless access system according to claim 1, wherein: the wireless access controller sends a wireless local area network configuration and an L 2TP tunnel configuration for the wireless access point. The method further includes the following steps: determining a forwarding type of the service set identifier configuration of the wireless local area network of the wireless access point, where the forwarding type includes centralized forwarding and local forwarding, and if the service set identifier is configured with centralized forwarding, the wireless access control The device will send a wireless local area network with a virtual local area network ID of 1-4096 to the wireless access point, and send the L2TP tunnel configuration at the same time. If the service set identifier is configured with local forwarding, Bay 1J The WLAN configuration and the L2TP tunnel configuration are not required to be delivered, and the data packets sent by the subsequent wireless clients are directly processed by the wireless access point.

[Claim 3] The interaction method of the L2TP-based radio access system according to claim 1, wherein: before the establishing the L2TP tunnel, the wireless access point further includes the following steps: detecting whether the data packet is Is sent to the wireless access point itself, if yes, processed by the wireless access point, if not, the wireless access point establishes an L2TP tunnel to the datagram according to the wireless local area network configuration and the L2TP tunnel configuration. The article is packaged.

[Claim 4] The interaction method of the L2TP-based wireless access system according to claim 1, wherein: the step of the wireless access point joining the wireless access controller via the Internet includes: a wireless access controller Pre-configuring information of the wireless access point, where the information includes version information and/or a MAC address;

The wireless access point is successfully powered on and joins the wireless access controller.

[Claim 5] The interaction method of the L2TP-based wireless access system according to claim 3, wherein: the radio access controller includes an uplink interface, a downlink interface, and an internal division with the radio access controller. a sub-interface corresponding to the virtual local area network interface, where the sub-interface includes a downlink sub-interface, a bridge interface, and a processing port for connecting to the L2TP tunnel; the radio access controller forwards the data packet by using the uplink The interface is sent to the broadband access server of the external network device; the wireless access controller encapsulates the Ethernet frame into the L2TP Layer 2 tunnel and sends the Ethernet interface to the bridge interface and the downlink sub-interface, and sends the packet to the wireless access point. If the data packet is detected and sent to the wireless access point itself, it is processed by the wireless access point via the bridge interface.

[Claim 6] The method for interacting with an L2TP-based wireless access system according to claim 1, wherein: the source port number of the wireless access point is determined by the wireless access controller as a wireless access point. Sending a wireless local area network configuration, an ID number generated from a database in which the wireless access point is imported into the wireless access controller, adding a source port number obtained by 30000 to the ID number; a destination port of the wireless access controller The number is 5247.

[Claim 7] An L2TP-based wireless access system, comprising: a wireless access point and a wireless access controller; the wireless access point includes: a first receiving module, configured to receive wireless The WLAN configuration and the L2TP tunnel configuration are sent by the access controller; the second receiving module is connected to the wireless client, and is configured to receive the data packet sent by the wireless client to access the external network; The first processing module is connected to the first receiving module and the second receiving module, and is configured to send the received wireless client by using the packet sent by the wireless access controller to perform the L2TP Layer 2 tunnel encapsulation. The data packet is converted into an Ethernet frame, and the L2TP tunnel is set up according to the WLAN configuration and the L2TP tunnel configuration, and the data packet is encapsulated and sent to the radio access controller. The second processing module is connected to the third receiving module. The source port number of the packet encapsulated in the L2TP Layer 2 tunnel is encapsulated, and the encapsulated packet is a tunnel packet, and is unpacked and forwarded to the wireless client.

The wireless access controller includes: a first sending module, connected to the first receiving module, configured to send a wireless local area network configuration and an L2TP tunnel configuration to a wireless access point; and a fourth receiving module, a processing module is connected to receive the encapsulated data packet sent by the wireless access point; the fifth receiving module is connected to the broadband access server of the external network device, and is configured to receive the reply from the broadband access server of the external network device. The third processing module is respectively connected to the broadband access server of the fourth receiving module and the external network device, and is configured to receive the encapsulated data packet sent by the wireless access point, to the transmission The layer checks the destination port number of the encapsulated data packet, and learns that the encapsulated data packet is a tunnel packet, performs unpacking, and forwards the data packet to the broadband access server of the external network device. The fourth processing module is respectively connected to the fifth receiving module and the third receiving module, and is configured to search for a path of the wireless client according to the mapping table of the port, and set the external network Packets Ethernet broadband access server replies L2TP A frame is encapsulated, and sent to the wireless access point.

[Claim 8] The L2TP-based wireless access system according to claim 7, wherein: the radio access controller further includes a determining module, and is connected to the first sending module, and is configured to determine if the wireless The service set of the wireless local area network of the access point identifies the forwarding type configured, and the forwarding type includes centralized forwarding and local forwarding.

[Claim 9] The L2TP-based wireless access system according to claim 7, wherein: The wireless access point further includes a detection module, which is respectively connected to the second receiving module and the first processing module, and is configured to detect whether the data packet sent by the wireless client is sent to the wireless access point itself.

The L2TP-based radio access system according to claim 7, wherein: the radio access controller further includes a configuration module, where the configuration module is configured to pre-configure information of the wireless access point. The information includes a version information and/or a MAC address. The wireless access point further includes a joining module, and is connected to the configuration module, and is configured to join the wireless access controller after the wireless access point is successfully powered on.