WO2014067450A1

WO2014067450A1 - Three-layer local forwarding method and device

Info

Publication number: WO2014067450A1
Application number: PCT/CN2013/086155
Authority: WO
Inventors: 关真珍
Original assignee: 华为技术有限公司
Priority date: 2012-10-30
Filing date: 2013-10-29
Publication date: 2014-05-08
Also published as: CN103795627B; CN103795627A

Abstract

Provided are a three-layer local forwarding method and device, the method comprising: receiving an uplink data packet transmitted by an STA, the uplink data packet being encapsulated in an Ethernet format, and the packet header being an Ethernet header; stripping the Ethernet header of the uplink data packet to acquire an uplink data packet having the Ethernet header stripped, and recording the Ethernet header; conducting first NAT on the uplink data packet having the Ethernet header stripped to acquire an uplink data packet after the first NAT; and transmitting the uplink data packet after the first NAT to an LTE network. An embodiment of the present invention realizes three-layer local forwarding, and can in turn cooperate with an LTE return network.

Description

Three-layer local forwarding method and device The present application claims priority to Chinese patent application filed on October 30, 2012, the Chinese Patent Office, the application number is 201210423913.5, and the invention name is "three-layer local forwarding method and device", the entire content of which is The citations are incorporated herein by reference. TECHNICAL FIELD The present invention relates to wireless communication technologies, and in particular, to a Layer 3 local forwarding method and device. A wireless local area network (WLAN) networking mode includes a fat access point (AP) and a thin AP. In the thin AP architecture, the thin AP and the wireless controller (Access Controller, AC) form a centralized management architecture. The thin AP "zero configuration" only implements the 802.11 air interface function. All configurations are centralized on the AC. Quality of Service (QoS), access control, load balancing, and AP control management. Under the networking structure of the thin AP+AC, there are two data forwarding modes, one is local forwarding and the other is centralized forwarding. Centralized forwarding means that a data tunnel is established between the thin AP and the AC. The thin AP sends data packets of all users to the AC through the data tunnel, and is forwarded by the AC. Local forwarding means that only the control channel is established between the AC and the thin AP. The functions of the network management, the authentication, and the load balancing are controlled by the AC. The data is transmitted to the AC through the tunnel. It is forwarded locally by the AP.

At present, the backhaul network that uses local forwarding for thin APs is mainly a fixed network, which only supports Layer 2 local forwarding. When Layer 2 local forwarding encapsulates data plane packets of WLAN users, it carries Ethernet.

( ethernet, eth ) header, through the eth header to complete the 4 艮 text of the uplink and downlink forwarding.

With the development of mobile broadband, WLAN can use Long Term Evolution (Long Term Evolution,

LTE) as a backhaul network. Since LTE is a Layer 3 network, air interfaces can only encapsulate Internet protocols.

(Internet Protocol, IP) Packets above the header cannot encapsulate packets carrying the eth header. Currently, thin APs generally only support Layer 2 local forwarding, relying on eth headers for message processing, resulting in thinning at present.

The AP local forwarding mode cannot cooperate with the LTE backhaul network. SUMMARY OF THE INVENTION In view of this, an embodiment of the present invention provides a Layer 3 local forwarding method and device, which is used to implement Layer 3 local forwarding, and thus can cooperate with an LTE backhaul network. In a first aspect, a three-layer local forwarding method is provided, including:

The first device receives the uplink data packet sent by the STA, where the uplink data packet is encapsulated in an Ethernet format, the packet header is an Ethernet header, and the destination MAC address included in the Ethernet header is not the first device. MAC address;

The first device strips the Ethernet header of the uplink data packet, obtains an uplink data file stripped of the Ethernet header, and records the Ethernet header;

The first device performs the first NAT on the uplink data packet stripped from the Ethernet header to obtain the uplink data packet after the first NAT, where the first NAT refers to the uplink that strips the Ethernet header. The source IP address in the data packet is replaced by the IP address of the STA as the IP address of the first device, and the source port number in the uplink data of the stripped Ethernet header is used by the STA. The port number is replaced with the port number of the first device;

The first device sends the uplink data packet after the first NAT to the LTE network. With reference to the first aspect, in a first possible implementation manner of the first aspect, the method further includes: the first device receiving a downlink data packet sent by the LTE network, where the downlink data packet is encapsulated in an IP format ;

The first device performs a second NAT on the downlink data packet to obtain a downlink data packet after the second NAT, where the second NAT is to use the destination IP address of the downlink data packet by the first The IP address of the device is replaced with the IP address of the STA, and the destination port number of the downlink data packet is replaced by the port number of the first device to the port number of the STA; The recorded Ethernet header encapsulates the downlink data packet after the second NAT in an Ethernet format, and the packet header is an Ethernet header, and the source MAC address of the encapsulated Ethernet header is the recorded Ethernet The destination MAC address of the network header, and the destination MAC address of the encapsulated Ethernet header is the source MAC address of the recorded Ethernet header;

STA.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the first Prepared as an access point AP;

Receiving, by the first device, an uplink data packet sent by the STA, where

Receiving, by the AP, an Ethernet packet sent by the STA through Layer 2;

The first device sends the uplink data packet after the first NAT to the LTE network, including:

The uplink data packet of the AP after the first NAT is encapsulated in an Ethernet format, and the packet header is an Ethernet header, and the source MAC address of the encapsulated Ethernet header is the MAC address of the first device. The destination MAC address of the encapsulated Ethernet header is the MAC address of the customer premises equipment CPE; the Ethernet header is stripped by the CPE and sent to the LTE network after performing the third NAT.

With reference to the first aspect, in a third possible implementation manner of the first aspect, the first device is a CPE;

Receiving, by the first device, an uplink data packet sent by the STA, where

The CPE receives an Ethernet packet sent by the STA via the AP, and the Ethernet packet is forwarded by the AP to the CPE.

The CPE sends the uplink data packet after the first NAT to the LTE network.

With reference to the first possible implementation of the first aspect, in a fourth possible implementation manner of the first aspect, the first device is an AP;

Receiving, by the first device, the downlink data packet sent by the LTE network, the method includes: the AP receiving, by the CPE, a downlink data packet encapsulated in an Ethernet format, where the data packet is subjected to the fourth NAT and the data is used. After the Ethernet format is encapsulated, the downlink data packet sent by the LTE network is a downlink data packet encapsulated in an IP format.

Before the first device performs the second NAT on the downlink data packet, the method further includes:

The AP strips the Ethernet header of the downlink data packet encapsulated by the CPE and encapsulates the Ethernet packet, so that the second NAT is performed on the downlink data packet stripped from the Ethernet header.

In combination with the first possible implementation of the first aspect, the fifth possible aspect of the first aspect In an implementation manner, the first device is a CPE;

Receiving, by the first device, the downlink data packet sent by the LTE network, where

STA, including:

The CPE will be used

Layer 2 forwarding is performed by the AP to the STA.

With reference to the second or fourth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, before the receiving, by the first device, the uplink data packet sent by the STA, Includes:

The AP sends the ARP packet or the DHCP packet to the AC through the CAPWAP tunnel of the wireless access point control protocol when the packet sent by the STA is an address resolution protocol ARP packet or a dynamic host configuration protocol DHCP message. The STA sends an uplink data packet according to the ARP packet or the DHCP packet.

In a second aspect, a Layer 3 local forwarding device is provided, including:

a first receiving module, configured to receive an uplink data packet sent by the STA, where the uplink data packet is encapsulated in an Ethernet format, the packet header is an Ethernet header, and the destination MAC address included in the Ethernet header is not Describe the MAC address of the first device;

a first processing module, configured to strip the Ethernet header of the uplink data packet, obtain an uplink data file that is stripped of the Ethernet header, and record the Ethernet header;

a second processing module, configured to perform, by performing a first NAT on the uplink data packet stripped from the Ethernet header, to obtain an uplink data packet after the first NAT, where the first NAT refers to stripping the Ethernet header The source IP address in the uplink data is replaced by the IP address of the STA as the IP address of the first device, and the source port number in the uplink data of the stripped Ethernet header is described by The port number of the STA is replaced with the port number of the first device;

The first sending module is configured to send the uplink data packet after the first NAT to the LTE network.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the method further includes: a second receiving module, configured to receive a downlink data packet sent by the LTE network, where the downlink data packet uses an IP address Format package

a third processing module, configured to perform a second NAT on the downlink data packet to obtain a second NAT a downlink data packet, where the second NAT is to replace the destination IP address of the downlink data packet with the IP address of the first device, and the downlink data packet. The destination port number of the text is replaced by the port number of the first device to the port number of the STA;

The fourth processing module is configured to encapsulate, in the Ethernet format, the downlink data packet after the second NAT according to the recorded Ethernet header, where the packet header is an Ethernet header, and the source of the encapsulated Ethernet header The MAC address is the destination MAC address of the recorded Ethernet header, and the destination MAC address of the encapsulated Ethernet header is the source MAC address of the recorded Ethernet header;

The second sending module is configured to send the downlink data packet encapsulated in the Ethernet format to the STA.

With reference to the second aspect, in a second possible implementation manner of the second aspect, the device is an access point AP;

The first receiving module is specifically configured to: receive an Ethernet packet sent by the STA through a layer 2;

The first sending module is specifically configured to: encapsulate the uplink data packet after the first NAT by using an Ethernet format, where the packet header is an Ethernet header, and the source MAC address of the encapsulated Ethernet header is The MAC address of the first device, the destination MAC address of the encapsulated Ethernet header is the MAC address of the CPE, and the uplink data packet encapsulated in the Ethernet format is sent to the CPE, and the CPE is used by the CPE. The Ethernet header is stripped and sent to the LTE network after performing the third NAT.

With reference to the second aspect, in a third possible implementation manner of the second aspect, the device is a user premises equipment CPE;

The first receiving module is specifically configured to: receive an Ethernet packet sent by the STA via the AP, where the Ethernet packet is forwarded by the AP to the CPE;

The first sending module is specifically configured to: send the uplink data packet after the first NAT to the LTE network.

With reference to the first possible implementation of the second aspect, in a fourth possible implementation manner of the second aspect, the device is an AP;

The second receiving module is specifically configured to: receive, by the CPE, a downlink data packet encapsulated in an Ethernet format, where the downlink data packet encapsulated in the Ethernet format is the downlink data sent by the CPE to the LTE network The packet is subjected to the fourth NAT and is encapsulated in an Ethernet format. The downlink data packet sent by the LTE network is a downlink data packet encapsulated in an IP format. Text

The third processing module is further configured to: strip the Ethernet header of the downlink data packet encapsulated by the CPE and encapsulated by the Ethernet format, so as to perform the foregoing on the downlink data packet stripped from the Ethernet header Two NAT.

With reference to the first possible implementation of the second aspect, in a fifth possible implementation manner of the second aspect, the first device is a CPE;

The second receiving module is specifically configured to: receive a downlink data packet that is encapsulated in the IP format and sent by the LTE network;

The second sending module is specifically configured to: send the downlink data packet encapsulated in the Ethernet format to the AP, and perform the Layer 2 forwarding to the STA by the AP.

In conjunction with the second or fourth possible implementation of the second aspect, in a sixth possible implementation of the second aspect, the method further includes:

The third sending module is configured to: when the packet sent by the STA is an ARP packet or a DHCP packet, the address resolution protocol ARP packet or the dynamic host configuration protocol DHCP is obtained through a wireless access point control protocol CAPWAP tunnel. The packet is sent to the AC, so that the STA obtains the address information according to the ARP packet or the DHCP packet, and then sends the uplink data packet.

Through the foregoing technical solution, the uplink packet of the STA can be forwarded in three layers to implement support for the LTE backhaul network.

BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present invention, a brief description of the drawings to be used in the description of the embodiments will be briefly made. It is obvious that the drawings in the following description are some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative labor. FIG. 1 is a schematic diagram of networking of LTE as a WLAN backhaul network according to the present invention;

2 is a schematic flowchart of an embodiment of a three-layer local forwarding method according to the present invention;

3 is a schematic flowchart of another embodiment of a three-layer local forwarding method according to the present invention;

4 is a schematic diagram of internal processing of a three-layer forwarding of a thin AP according to the present invention;

FIG. 5 is a schematic diagram of internal processing of a three-layer forwarding of a CPE according to the present invention; FIG. 6 is a schematic flowchart of another embodiment of a three-layer local forwarding method according to the present invention;

7 is a schematic flowchart of another embodiment of a three-layer local forwarding method according to the present invention;

8 is a schematic flowchart of an embodiment of a Layer 3 local forwarding device according to the present invention;

FIG. 9 is a schematic flowchart diagram of another embodiment of a three-layer local forwarding method according to the present invention.

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. The embodiments are a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As users' demand for data services increases, global operators are embarking on the deployment of LTE networks to provide users with a better mobile broadband experience. However, the LTE industry chain is relatively lagging behind, and LTE intelligent terminals are not popular. In order to reduce the terminal access threshold of LTE networks and provide users with high-speed and smooth data services, the use of WLAN as an extension of LTE networks and user access has become an operation. The common choice of the merchants is that users can access the LTE network through the WLAN and enjoy the broadband service of the LTE network.

Referring to FIG. 1 , a schematic diagram of LTE as a WLAN backhaul network, where a WLAN network includes a station (Station, STA) as a WLAN terminal and a thin AP and an AC, and a control channel is established between the thin AP and the AC. Forward control plane messages. The thin AP can access the Customer Premises Equipment (CPE) in the LTE network. The CPE can access the Internet through the evolved NodeB (eNB) in the LTE network and other devices in the LTE network. The devices in the core network, such as the Broadband Remote Access Server (BRAS), the Portal (Portal) server, and the Authentication Authorization Accounting (AAA) server, complete the access authentication for the STA. Assign an IP address.

In the local forwarding mode, after the AC notifies the AP to initiate the local forwarding function, the data plane packets of the user are directly forwarded by the AP through the LTE network.

The uplink data packet sent by the STA to the AP in the prior art is an Ethernet packet, and the AP enters In the case of the line forwarding, the Layer 2 forwarding mode is also adopted. However, after the AP accesses the LTE network, the LTE is a Layer 3 network and cannot support Layer 2 packet forwarding. In order to cooperate with the LTE backhaul network, the present invention provides the following embodiments.

2 is a schematic flowchart of a method for a local layer forwarding method according to an embodiment of the present invention, including: Step 21: The first device receives an uplink data packet sent by a STA, and the uplink data packet is encapsulated in an Ethernet format, and the packet header is encapsulated. For the Ethernet header, the destination media access control (MAC) address included in the Ethernet header is not the MAC address of the first device;

Step 22: The first device strips the Ethernet header of the uplink data packet, obtains an uplink data stripped from the Ethernet header, and records the Ethernet header.

Step 23: The first device performs a first network address translation (NAT) on the uplink data packet with the Ethernet header stripped, and obtains an uplink data packet after the first NAT, where the first The NAT means that the source IP address in the uplink data packet stripped from the Ethernet header is replaced by the IP address of the STA to the IP address of the first device, and the uplink of the Ethernet header is stripped. The source port number in the data>3⁄4 text is replaced by the port number of the STA to the port number of the first device.

Step 24: The first device sends the uplink data packet after the first NAT to the LTE network.

The foregoing process is an uplink process. Correspondingly, the downlink process may be as shown in FIG. 3, including: Step 31: The first device receives a downlink data packet sent by the LTE network, and the downlink data packet uses an IP format. Package

Step 32: The first device performs a second NAT on the downlink data packet to obtain a downlink data packet after the second NAT, where the second NAT refers to the destination IP address of the downlink data packet. The IP address of the first device is replaced with the IP address of the STA, and the destination port number of the downlink data packet is replaced by the port number of the first device to the port number of the STA;

Step 33: The first device encapsulates the downlink data packet after the second NAT according to the recorded Ethernet header in an Ethernet format, where the packet header is an Ethernet header, and the source MAC address of the Ethernet header The address is the destination MAC address of the recorded Ethernet header, and the destination MAC address of the Ethernet header is the source MAC address of the recorded Ethernet header;

Step 34: The first device sends the downlink data packet encapsulated in the Ethernet format. Give the STA.

The first device may be an AP, and may be a thin AP, or may be a CPE. When the first device is a thin AP, refer to Figure 4, which is a schematic diagram of the internal processing of the Layer 3 forwarding of the thin AP.

When the uplink data is transmitted, the wifi module receives the uplink data packet sent by the STA, and the uplink data packet is a Layer 2 data packet encapsulated with an Ethernet header, and the STAs may use a Service Set Identifier (SSID). The virtual local area network (VLAN) is isolated. For example, one STA has SSID1 and VLAN1, and the other STA has SSID2 and VLAN2.

After the wifi module receives the uplink data packet encapsulated with the Ethernet header, the MAC layer processing module can strip the Ethernet header and record the Ethernet header. The Ethernet header can include: a source MAC address, a destination MAC address, and a VLAN. Information, etc. The source MAC address is the MAC address of the STA, and the destination MAC address is the MAC address of the gateway, such as the MAC address of the BRAS.

Afterwards, the MAC layer processing module of the thin AP can send the uplink data packet stripped off the Ethernet header to the NAT module of the thin AP.

The NAT module of the thin AP performs the first NAT on the uplink data packet stripped from the Ethernet header. The first NAT means that the source IP address in the uplink data packet is replaced by the IP address of the STA as the IP address of the thin AP, and the source port number is replaced by the port number of the STA as the port number of the thin AP. The destination IP address and destination port number of the upstream data packet are unchanged. They are the IP address and port number of the service server accessed by the user, for example, the IP address of the Session Initiation Protocol (SIP) server. The port number. The NAT module can also record a NAT entry, which records the replacement IP address and the correspondence between the port numbers.

Then, the NAT module of the thin AP sends the uplink data packet of the first NAT to the routing module, and the routing module searches the routing table according to the destination IP address to find the next hop for routing and forwarding.

In this embodiment, the next hop of the thin AP is the CPE. Therefore, the routing module sends the uplink data packet after the first NAT to the MAC layer processing module of the thin AP, and the MAC layer processing module of the thin AP encapsulates the Ethernet header. The source MAC address of the encapsulated Ethernet header is the MAC address of the thin AP, and the destination MAC address is the MAC address of the CPE.

After that, the MAC layer processing module of the thin AP sends the uplink data packet of the Ethernet encapsulation to the CPE, and sends the packet to the LTE network via the CPE.

When the downlink data is transmitted, the MAC layer processing module of the thin AP receives the downlink number forwarded by the CPE. According to the packet, the downlink data packet sent by the LTE network is a Layer 3 packet, and the Layer 3 packet is a packet encapsulated in an IP format, that is, a data packet encapsulated with at least an IP header. After receiving the Layer 3 packet sent by the LTE network, the CPE first performs NAT on the Layer 3 packet, and replaces the destination IP address and the destination port number with the IP address of the AP and the port number of the thin AP, respectively. The downlink data packet is encapsulated in Ethernet. The source MAC address of the encapsulated Ethernet header is the MAC address of the CPE, and the destination MAC address is the MAC address of the thin AP.

Then, the MAC layer processing module of the thin AP strips off the Ethernet header of the CPE, and sends the downlink data packet stripped from the Ethernet header to the NAT module of the thin AP.

The NAT module of the thin AP performs the second NAT, and the destination IP address in the downlink data packet is converted from the IP address of the thin AP to the IP address of the STA, and the destination port number is replaced by the port number of the thin AP to the port number of the STA. The NAT module can perform the above replacement according to the previously recorded NAT entry.

After that, the NAT module of the thin AP sends the downlink data packet after the second NAT to the MAC layer processing module of the thin AP, and the MAC layer processing module of the thin AP encapsulates the received downlink data packet according to the recorded Ethernet header. The destination MAC address of the encapsulated Ethernet header is the source MAC address of the recorded MAC header, and the source MAC address of the encapsulated Ethernet header is the destination MAC address of the recorded MAC header, that is, the encapsulated Ethernet header The destination MAC address is the MAC address of the STA, and the source MAC address of the encapsulated Ethernet header is the MAC address of the BRAS.

After that, the MAC layer processing module of the thin AP sends the downlink data packet of the Ethernet encapsulation to the STA through the wifi module.

In addition, the thin AP can establish a control channel with the AC through the Control and Provisioning of Wireless Access Points Protocol (CAPWAP) module to transmit control information, or when the thin AP recognizes that the STA sends the dynamic information. The DHCP server or the address resolution protocol (ARP) sends the DHCP packets or ARP packets to the AC.

When the first device is a CPE, refer to FIG. 5, which is a schematic diagram of internal processing of the Layer 3 forwarding of the CPE. When the uplink data is transmitted, the MAC layer processing module of the CPE receives the uplink data packet encapsulated with the Ethernet header sent by the thin AP, and strips the Ethernet header, and records the Ethernet header, and the Ethernet header may include : Source MAC address, destination MAC address information, etc. The source MAC address is the MAC address of the STA, and the destination MAC address is the MAC address of the BRAS. Will be stripped off The NAT module of the CPE performs the first NAT on the uplink data packet stripped from the Ethernet header. The source IP address of the uplink data is translated from the IP address of the STA to the IP address of the CPE, and the source port number is replaced by the port number of the STA to the port number of the CPE, and the NAT entry can be recorded. Record the correspondence between the replaced IP address and the port number. Then, the NAT module sends the uplink data packet after the first NAT to the LTE module (Modem), and the LTE module forwards the packet to the uplink data packet after the first NAT in the LTE air interface.

When the downlink data is transmitted, the LTE module receives the downlink data packet sent by the LTE air interface, and the downlink data packet is a Layer 3 packet, and then sent to the NAT module of the CPE.

The NAT module of the CPE can perform the second NAT on the received downlink data packet according to the previously recorded NAT entry, that is, the destination IP address in the downlink data packet is replaced by the IP address of the CPE as the IP address of the STA, and the destination port is used. The number is replaced by the port number of the CPE as the port number of the STA. Then, the downlink data packet after the second NAT is sent to the MAC layer processing module of the CPE.

The MAC layer processing module of the CPE encapsulates the Ethernet header for the downlink data packet after the second NAT according to the previously recorded Ethernet header. The destination MAC address of the encapsulated Ethernet header is the source MAC address of the recorded Ethernet header. The source MAC address of the encapsulated Ethernet is the destination MAC address of the recorded Ethernet header, that is, the destination MAC address of the encapsulated Ethernet header is the MAC address of the STA, and the source MAC address is the MAC address of the BRAS.

FIG. 6 is a schematic flowchart of another embodiment of a Layer 3 local forwarding method according to the present invention. This example uses a thin AP to strip the Ethernet header and NAT as an example. This embodiment includes:

Step 601: The CPE completes the LTE network access process.

Step 602: The thin AP is powered on, and the CPE allocates an IP address to the thin AP.

Step 603: The thin AP discovers and selects AC.

Step 604: The thin AP joins the AC to establish a CAPWAP tunnel with the AC.

Step 605: The AC configures parameters for the thin AP.

For example, the AC sends an SSID and a VLAN based on a virtual access point (VAP) to isolate users.

Step 606: The STA sends a WLAN association request to the thin AP.

Step 607: The thin AP notifies the AC STA association to complete the STA configuration.

Step 608: The STA completes the IP address obtaining and authentication process through the tunnel.

For example, the STA initiates a DHCP request, and the thin AP sends the DHCP request from the CAPWAP tunnel. It is sent to the AC, which is then sent by the AC to the BRAS. The BRAS assigns an IP address to the STA. In addition, the AAA server can complete WLAN side authentication for the STA.

Step 609: After the STA authentication is passed, the AC notifies the thin AP to start the local forwarding function for the STA.

•6匕

dagger.

The above steps 603 to 609 are normal STA access WLAN processes. For details, refer to the existing process.

Optionally, the AC can also notify the thin AP whether to enable Layer 2 forwarding or Layer 3 forwarding.

Step 610: After determining that the local forwarding function is Layer 3 forwarding, the thin AP performs stripping Ethernet headers, NAT processing, and re-encapsulating the Ethernet headers, and then forwarding the Ethernet headers to the CPE.

The thin AP can determine whether it is Layer 2 forwarding or Layer 3 forwarding according to the indication of the AC; or

A thin AP can also be configured locally. The local configuration uses Layer 3 forwarding or Layer 2 forwarding. If it is a three-layer forwarding, the three-layer forwarding process according to the embodiment of the present invention is used. If the layer 2 forwarding is used, the prior art process can be used.

For details of the processing of the Layer 3 forwarding, refer to the related description of the thin AP in Figure 4 above. Step 611: The CPE performs stripping Ethernet header and NAT processing on the received uplink data packet, and sends the processed uplink data to the Internet through an LTE evolved Packet Network-EPC (EPC).

The CPE may first strip the Ethernet header encapsulated by the thin AP and perform NAT on the uplink data packet of the stripped Ethernet header, that is, the source IP address and the source port number of the uplink data packet are respectively determined by the STA's IP address and The port number is replaced with the IP address and port number of the CPE, and then sent to the Internet through the LTE network. In addition, the CPE can also record stripped Ethernet headers for downstream packaging. In addition, for the downlink, the following processes may be included:

The CPE receives the downlink data packet sent by the LTE network, and the downlink data packet is encapsulated in an IP format (or a packet header encapsulated with an IP header or more);

The CPE performs NAT on the downlink data packet encapsulated in the IP format, and uses the Ethernet format encapsulation (or the encapsulated Ethernet header) to send the downlink data packet of the NAT and the encapsulated Ethernet header to the AP. In the case of NAT, the destination IP address of the downstream data packet is replaced by the IP address of the CPE to the IP address of the AP, and the destination port number is replaced by the port number of the CPE as the port number of the AP. The conversion can be based on the NAT recorded in the uplink. The entry determines the corresponding replacement relationship. Seal Address, the encapsulated Ethernet header can be determined based on the Ethernet header recorded at the upstream.

ΑΡ First strip the Ethernet header, and perform NAT, which is based on the recorded NAT entry, replacing the destination IP address with the IP address of the AP with the IP address of the STA, and replacing the destination port number with the port number of the AP. And the AP encapsulates the corresponding Ethernet header for the downlink data packet after the NAT according to the Ethernet header recorded in the uplink; it is understood that, in this embodiment, the first NAT refers to the thinning in step 610. The NAT processing of the uplink data packet by the AP, the third NAT is the NAT processing performed by the CPE on the uplink data packet in the step 611, and the second NAT is the NAT processing performed by the thin AP on the downlink data packet, and the fourth NAT refers to the NAT processing performed by the CPE on downlink data packets. The AP in this embodiment can strip the Ethernet header and perform NAT on the uplink. The downlink can be restored according to the previously recorded Ethernet header information. Therefore, the received Layer 2 packet can be converted into a Layer 3 packet for transmission. To the LTE network.

FIG. 7 is a schematic flowchart of another embodiment of a three-layer local forwarding method according to the present invention. In this embodiment, a CPE stripping Ethernet header and a NAT are taken as an example. This embodiment includes:

Step 701: The CPE completes the LTE network access process.

Step 702: The thin AP is powered on, and the CPE allocates an IP address to the thin AP.

Step 703: The thin AP discovers and selects AC.

Step 704: The thin AP joins the AC to establish a CAPWAP tunnel with the AC.

Step 705: The AC configures parameters for the thin AP.

Step 706: The STA sends a WLAN association request to the thin AP.

Step 707: The thin AP notifies the AC STA association to complete the STA configuration.

Step 708: The STA completes the IP address obtaining and authentication process through the tunnel.

Step 709: After the STA authentication is passed, the AC notifies the thin AP to start the local forwarding function for the STA.

•6匕

dagger.

For details of the above steps 701 709, refer to step 601 609.

Step 710: After starting the local forwarding function, the thin AP follows the Layer 2 local forwarding mode.

The uplink data packet sent by the STA is sent to the CPE.

In addition, the thin AP sends a DHCP packet or an ARP packet to the AC through the CAPWAP tunnel. Step 711: The CPE performs stripping Ethernet header and NAT processing on the uplink data, and then sends the data to the Internet through the LTE EPC network.

For details of the processing of the Layer 3 forwarding, refer to the description of the CPE in Figure 4 above. In addition, for the downlink, the following processes may be included:

The CPE receives the downlink data packet sent by the LTE network, and the downlink data packet is encapsulated with a header above the IP header;

The CPE performs NAT, that is, the destination IP address is replaced with the IP address of the STA by the IP address of the CPE, and the port number of the CPE is replaced by the port number of the STA, and the CPE is based on the recorded NAT entry. The Ethernet header recorded in the uplink, and the corresponding Ethernet header is encapsulated in the downlink data packet after the NAT;

The AP sends the downlink data packet to the corresponding STA through the Layer 2 forwarding mode according to the information of the Ethernet header.

It is to be understood that, in this embodiment, the first NAT refers to the NAT processing performed by the CPE on the uplink data packet in the step 711, and the second NAT refers to the NAT processing performed by the CPE on the downlink data packet.

The CPE in this embodiment can strip the Ethernet header and perform NAT on the uplink. The downlink can be restored according to the previously recorded Ethernet header information. Therefore, the received Layer 2 packet can be converted into a Layer 3 packet for transmission. To the LTE network.

FIG. 8 is a schematic structural diagram of an embodiment of a three-layer local forwarding device according to the present invention. The device may be a device that performs the foregoing method, and the device includes a first receiving module 81, a first processing module 82, a second processing module 83, and a first The sending module 84 is configured to receive an uplink data packet sent by the STA, where the uplink data packet is encapsulated in an Ethernet format, and the packet header is an Ethernet header, and the destination of the Ethernet header is included. The MAC address is not the MAC address of the first device; the first processing module 82 is configured to strip the Ethernet header of the uplink data packet, obtain an uplink data packet with the Ethernet header stripped, and record the The second processing module 83 is configured to perform the first NAT on the uplink data packet stripped from the Ethernet header to obtain the uplink data packet after the first NAT, where the first NAT refers to the stripping The source IP address in the uplink data packet of the Ethernet header is replaced by the IP address of the STA as the IP address of the first device, and the source port in the uplink data of the Ethernet header is stripped No. After first sending the first module 84 for the NAT; STA alternative port number for the port number of the first device The uplink data packet is sent to the LTE network.

Optionally, the device may further include:

a second receiving module, configured to receive a downlink data packet sent by the LTE network, where the downlink data packet is encapsulated with a packet header above an IP header;

The third processing module is configured to perform a second NAT on the downlink data packet to obtain a downlink data packet after the second NAT, where the second NAT is to use the destination IP address of the downlink data packet The IP address of the first device is replaced with the IP address of the STA, and the destination port number of the downlink data packet is replaced by the port number of the first device to the port number of the STA;

Optionally, the device is an AP;

The first sending module is specifically configured to: encapsulate the uplink data packet after the first NAT by using an Ethernet format, where the packet header is an Ethernet header, and the source MAC address of the encapsulated Ethernet header is The MAC address of the first device, the destination MAC address of the encapsulated Ethernet header is the MAC address of the CPE, and the uplink data packet encapsulated in the Ethernet format is sent to the CPE, and is stripped by the CPE. The Ethernet header is sent to the LTE network after performing the third NAT.

Optionally, the device is a CPE;

Optionally, the device is an AP;

The second receiving module is specifically configured to: receive, by the CPE, a downlink data packet encapsulated in an Ethernet format, where the downlink data packet encapsulated in the Ethernet format is the CPE pair The downlink data packet sent by the LTE network is obtained by using the fourth NAT and the Ethernet format, and the downlink data packet sent by the LTE network is a downlink data packet encapsulated in the IP format.

Optionally, the first device is a CPE;

Optionally, the device may further include:

The determining module is configured to determine whether to use the three-layer local forwarding mode, and to perform the three-layer local forwarding mode when determining that the three-layer local forwarding mode is used, and the determining whether to use the three-layer local forwarding mode includes:

And receiving the indication information sent by the AC, where the indication information is used to indicate whether the indication of the three-layer local forwarding mode is used, and whether the three-layer local forwarding mode is used according to the indication information; or

According to the local configuration, whether the configuration information of the Layer 3 local forwarding mode is used, and whether the Layer 3 local forwarding mode is used is determined according to the configuration information.

Optionally, the device may further include:

The third sending module is configured to send the ARP packet or the DHCP packet to the AC and describe the uplink data packet by using the CAPWAP tunnel when the packet sent by the STA is an ARP packet or a DHCP packet.

It can be understood that, when the device is an AP, the functions performed by the first receiving module and the second sending module in this embodiment are completed by the wifi module in FIG. 4, and the first processing module, the second receiving module, and the fourth The function completed by the processing module can be completed by the MAC layer processing module in FIG. 4, and the functions performed by the second processing module and the third processing module can be completed by the NAT module in FIG. 4, and the function performed by the first sending module can be performed by FIG. 4 The routing module and the MAC layer processing module are completed.

When the device is a CPE, the first receiving module, the first processing module, and the first The functions performed by the four processing modules and the second sending module may be completed by the MAC layer processing module in FIG. 5, and the functions performed by the second processing module and the third processing module may be completed by the NAT module in FIG. 5, the first sending module and The functions performed by the second receiving module can be completed by the LTE module in FIG.

In this embodiment, the Ethernet header can be stripped and the NAT can be performed in the uplink. The downlink can be restored according to the previously recorded Ethernet header information. Therefore, the received Layer 2 packet can be converted into a Layer 3 packet for transmission to the The LTE network supports the LTE network as a backhaul network.

FIG. 9 is a schematic structural diagram of another embodiment of a three-layer local forwarding device according to the present invention. The device may be a device that performs the foregoing method. The device includes a transceiver 91 and a processor 92, and the transceiver 91 is configured to receive uplink data sent by the STA. The packet is encapsulated in an Ethernet format, and the header is an Ethernet header. The destination MAC address of the Ethernet header is not the MAC address of the first device, and the processor 92 is used for stripping. The Ethernet header of the uplink data packet is obtained by stripping an uplink data packet of the Ethernet header, and recording the Ethernet header; performing first NAT on the uplink data packet stripped from the Ethernet header Obtaining an uplink data packet after the first NAT, where the first NAT is to replace the source IP address in the uplink data packet with the stripped Ethernet header from the IP address of the STA to the first device. IP address, and the source port number in the uplink data packet stripped from the Ethernet header is replaced by the port number of the STA as the port number of the first device; the transceiver 91 is also used to After the first NAT uplink data packet to the LTE network.

Optionally, the transceiver 91 is further configured to receive the downlink data packet sent by the LTE network, where the downlink data packet is encapsulated in an IP format.

The processor 92 is further configured to perform a second NAT on the downlink data packet to obtain a downlink data packet after the second NAT, where the second NAT is to use the destination IP address of the downlink data packet by the The IP address of the first device is replaced with the IP address of the STA, and the destination port number of the downlink data packet is replaced by the port number of the first device to the port number of the STA; The first downlink packet of the second NAT is encapsulated in an Ethernet format, and the packet header is an Ethernet header, and the source MAC address of the encapsulated Ethernet header is the purpose of the recorded Ethernet header. a MAC address, and a destination MAC address of the encapsulated Ethernet header is a source MAC address of the recorded Ethernet header;

The transceiver 91 is further configured to send the downlink data packet encapsulated in the Ethernet format to the STA. Optionally, the device may be an AP, and the transceiver 91 may be specifically configured to receive an Ethernet packet sent by the STA through the second layer. The processor 92 is further configured to: send the uplink data packet after the first NAT. Encapsulated in the Ethernet format, the packet header is an Ethernet header, the source MAC address of the encapsulated Ethernet header is the MAC address of the first device, and the destination MAC address of the encapsulated Ethernet header is the MAC of the CPE. address;

The transceiver 91 is specifically configured to send the uplink data packet encapsulated in the Ethernet format to the CPE, and the CPE strips the Ethernet header and sends the third NAT to the LTE network.

Optionally, the device is a CPE, and the transceiver 91 is specifically configured to receive an Ethernet packet sent by the STA by using an AP, where the Ethernet packet is forwarded by the AP to the CPE. The uplink data packet after the first NAT is sent to the LTE network.

Optionally, the device is an AP, and the transceiver 91 is configured to receive, by the CPE, a downlink data packet encapsulated in an Ethernet format, where the downlink data packet encapsulated in the Ethernet format is the CPE to the LTE. The downlink data packet sent by the network is obtained by using the fourth NAT and the Ethernet format, and the downlink data packet sent by the LTE network is a downlink data packet encapsulated in the IP format; the processor 92 is also used for The Ethernet header of the downlink data packet encapsulated by the CPE and encapsulated by the Ethernet format is stripped to perform the second NAT on the downlink data packet stripped from the Ethernet header.

Optionally, the device is a CPE, and the transceiver 91 is configured to receive the downlink data packet encapsulated in the IP format sent by the LTE network, and send the downlink data packet encapsulated in the Ethernet format to the The AP is forwarded by the AP to the STA.

Optionally, the processor 92 is further configured to determine whether to use the Layer 3 local forwarding mode, and when determining that the Layer 3 local forwarding mode is used, performing the Layer 3 local forwarding, where the determining whether to use Layer 3 local forwarding Ways include:

And receiving the indication information sent by the AC, where the indication information is used to indicate whether the indication of the local layer forwarding mode is used, and whether the three-layer local forwarding mode is used according to the indication information; or, according to whether the local configuration is configured, The configuration information of the Layer 3 local forwarding mode is used to determine whether to use the Layer 3 local forwarding mode according to the configuration information.

Optionally, the processor 92 is further configured to send, by using the CAPWAP tunnel, the ARP packet or the DHCP packet to send the uplink data packet, when the message sent by the STA is an ARP file or a DHCP message. The above transceiver may be an independent transmitter and receiver, respectively performing a transmitting function and a receiving function, or may be a device that is combined to specifically transmit a function and a receiving function. Specifically, the network cable, the optical fiber, or the antenna may be used. The antenna may be a linear antenna, a loop antenna, an array antenna, or the like.

The above processor may be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. . A general purpose processor can be a microprocessor or any conventional processor.

In addition, the device may also include a memory, which may be a random access memory, a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register, and the like. And, a bus system may be included, and the bus system includes, for example, a data bus, a power bus, a control bus, or a status signal bus.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the division of each functional module described above is exemplified. In practical applications, the above-mentioned function assignment can be completed by different functional modules as needed. The internal structure of the device is divided into different functional modules to perform all or part of the functions described above. For the specific working process of the system, the device and the unit described above, reference may be made to the corresponding process in the foregoing method embodiments, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be used. Combined or can be integrated into another system, or some features can be ignored, or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form. The components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. You can choose which one according to your actual needs. Some or all of the units implement the objectives of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application, in essence or the contribution to the prior art, or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. The instructions include a plurality of instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like, which can store program codes. .

The above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that The technical solutions described in the embodiments are modified, or some of the technical features are equivalently replaced; and the modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

Rights request

A three-layer local forwarding method, comprising: receiving, by a first device, an uplink data packet sent by a station STA, where the uplink data packet is encapsulated in an Ethernet format, and the packet header is an Ethernet header. The destination medium access control MAC address included in the Ethernet header is not the MAC address of the first device;

The first device performs a first network address translation NAT on the uplink data packet stripped from the Ethernet header to obtain an uplink data packet after the first NAT, where the first NAT refers to stripping the Ethernet The source IP address in the uplink data packet of the header is replaced by the IP address of the STA as the IP address of the first device, and the source port number in the uplink data of the stripped Ethernet header is discarded. The port number of the STA is replaced by the port number of the first device;

The first device sends the uplink data packet after the first NAT to the Long Term Evolution (LTE) network.

2. The method according to claim 1, further comprising:

Receiving, by the first device, a downlink data packet sent by the LTE network, where the downlink data packet is encapsulated in an IP format;

STA.

3. The method according to claim 1, wherein the first device is an access point

AP; The receiving, by the first device, the uplink data packet sent by the STA includes:

Receiving, by the AP, an Ethernet packet sent by the STA through Layer 2;

The method according to claim 1, wherein the first device is a CPE, and the first device receives an uplink data packet sent by the STA, including:

The CPE sends the uplink data packet after the first NAT to the LTE network.

The method according to claim 2, wherein the first device is an AP, and the first device receives a downlink data packet sent by the LTE network, where: the AP receives a CPE sent by the AP. The downlink data packet encapsulated in the Ethernet format is obtained by the fourth NAT and the Ethernet format. The downlink data packet sent by the LTE network is the downlink data encapsulated in the IP format. Before the first device performs the second NAT on the downlink data packet, the method further includes:

The method according to claim 2, wherein: the first device is a CPE; and the first device receives a downlink data packet that is sent by the LTE network, and includes:

STA, including: Layer 2 forwarding is performed by the AP to the STA.

The method according to claim 3 or 5, wherein, before the first device receives the uplink data packet sent by the STA, the method further includes:

8. A three-layer local forwarding device, comprising:

a first receiving module, configured to receive an uplink data packet sent by the station STA, where the uplink data packet is encapsulated in an Ethernet format, the packet header is an Ethernet header, and the destination media access control included in the Ethernet header The MAC address is not the MAC address of the first device;

a second processing module, configured to perform, by performing a first network address translation NAT on the uplink data packet stripped from the Ethernet header, to obtain an uplink data packet after the first NAT, where the first NAT refers to stripping the The source IP address in the uplink data of the Ethernet header is replaced by the IP address of the STA to the IP address of the first device, and the source port number in the uplink data packet in which the Ethernet header is stripped. The port number of the STA is replaced by the port number of the first device. The first sending module is configured to send the uplink data packet after the first NAT to the Long Term Evolution (LTE) network.

9. The device according to claim 8, further comprising:

a second receiving module, configured to receive a downlink data packet sent by the LTE network, where the downlink data packet is encapsulated in an IP format;

The fourth processing module is configured to encapsulate, in the Ethernet format, the downlink data packet after the second NAT according to the recorded Ethernet header, where the packet header is an Ethernet header, and the encapsulated Ethernet header The source MAC address is the destination MAC address of the recorded Ethernet header, and the destination MAC address of the encapsulated Ethernet header is the source MAC address of the recorded Ethernet header;

The device according to claim 8, wherein the device is an access point AP, and the first receiving module is specifically configured to: receive an Ethernet packet sent by the STA through a layer 2;

The device according to claim 8, wherein the device is a customer premises equipment CPE;

The device according to claim 9, wherein the device is an AP;

The second receiving module is specifically configured to: receive, by the CPE, a downlink data packet encapsulated in an Ethernet format, where the downlink data packet encapsulated in the Ethernet format is the downlink data sent by the CPE to the LTE network The downlink data packet sent by the LTE network is a downlink data packet encapsulated in an IP format, and is obtained by using the fourth NAT and the Ethernet format.

The device according to claim 9, wherein the first device is a CPE, and the second receiving module is specifically configured to: receive a packet header encapsulated by the LTE network and encapsulated in an IP format Downstream data message;

The second sending module is specifically configured to: use the downlink datagram encapsulated by the Ethernet format The message is sent to the AP, and is forwarded by the AP to the STA.

The device according to claim 10 or 12, further comprising: a third sending module, configured to: when the packet sent by the STA is an ARP packet or a DHCP packet, The point control protocol CAPWAP tunnel sends the address resolution protocol ARP packet or the dynamic host configuration protocol DHCP packet to the AC, so that the STA obtains the address information according to the ARP packet or the DHCP packet, and then sends the uplink datagram. Text.