CN110650077A - A method and system for separating L2TP protocol control and forwarding - Google Patents

Abstract

The invention discloses a method and system for separating L2TP protocol control and forwarding. The method includes: a LAC-U receives a PPPoE protocol message sent by a user terminal, and forwards the PPPoE protocol message to a BNG/vBNG-C; The LAC-U receives the first L2TP protocol message fed back by the BNG/vBNG-C according to the PPPoE protocol message, and forwards the first L2TP protocol message to the LNS-U, wherein the first L2TP protocol message is An L2TP protocol packet carries the IP address of the LNS-U; the LAC-U receives the second L2TP protocol packet fed back by the LNS-U according to the first L2TP protocol packet, and according to the first L2TP protocol packet Two L2TP protocol packets establish an L2TP tunnel and session with the LNS-U.

Description

A method and system for separating L2TP protocol control and forwarding

technical field

The present invention relates to the technical field of communications, in particular to a method and system for separating L2TP protocol control and forwarding.

Background technique

With the development of SDN (Software Defined Network, Software Defined Network) technology and NFV (Network Function Virtualization, Network Function Virtualization) technology, traditional network element devices have evolved from specialization to generalization. The evolution of traditional network element equipment from specialization to generalization mainly requires two decouplings: decoupling of control and forwarding, and decoupling of software and hardware.

As a traditional broadband access gateway device, BNG (Broadcast Network Gateway) is very important in user broadband access services and scenarios. L2TP (Layer 2Tunnel Protocol, Layer 2 Tunnel Protocol) user access is a BNG device. important function. The main requirements for BNG equipment L2TP user access are user authentication and access control. With the continuous emergence of various Internet services, the requirements for the number of L2TP user sessions supported by BNG devices continue to increase, the access bandwidth for L2TP users continues to increase, and the requirements for devices to provide open and programmable services to the outside world are getting higher and higher. Based on these factors, it is very necessary for BNG devices to realize the two decouplings mentioned above based on the SDN/NFV architecture.

The decoupling of BNG forwarding and control is a trend. After the forwarding and control are decoupled, the control plane can manage multiple forwarding planes and perform flexible scheduling of users, traffic, and resources among multiple forwarding planes. Utilization and reliability can be greatly improved. Therefore, with the realization of the decoupling of BNG forwarding and control, the L2TP user access protocol also needs to decouple forwarding and control.

SUMMARY OF THE INVENTION

The solution provided according to the embodiment of the present invention solves the problem that the separation between forwarding and control of the L2TP protocol cannot be realized in the prior art.

A method for separating L2TP protocol control and forwarding provided according to an embodiment of the present invention includes:

The LAC-U (L2TP Access Concentrator-User Plane, L2TP access convergence point-forwarding plane) receives the PPPoE protocol packet sent by the user terminal, and forwards the PPPoE protocol packet to the BNG/vBNG-C (BNG/vBNG Control Plane , BNG/vBNG control plane);

The LAC-U receives the first L2TP protocol packet fed back by the BNG/vBNG-C according to the PPPoE protocol packet, and forwards the first L2TP protocol packet to the LNS-U (L2TP Network Server User Plane , L2TP network server-forwarding plane), wherein, the IP address of the LNS-U is carried in the first L2TP protocol packet;

The LAC-U receives the second L2TP protocol message fed back by the LNS-U according to the first L2TP protocol message, and establishes an L2TP with the LNS-U according to the second L2TP protocol message Tunnels and sessions.

Preferably, after the LAC-U establishes the L2TP tunnel and session with the LNS-U according to the second L2TP protocol message, the method further includes:

The LAC-U sends the data forwarding flow to the LNS-U in the case of receiving the data forwarding flow sent by the user terminal;

In the case of receiving the control packet sent by the user terminal, the LAC-U forwards the control packet to the BNG/vBNG-C via the LNS-U, so that the BNG/vBNG-C can Session negotiation and address allocation, and deliver user entries to the LNS-U after session negotiation.

Preferably, after the LAC-U receives the PPPoE protocol packet sent by the user terminal and forwards the PPPoE protocol packet to the BNG/vBNG-C, the method further includes:

The BNG/vBNG-C determines whether the user terminal is an L2TP terminal according to the PPPoE protocol message;

If the determination result is yes, construct the first L2TP protocol packet, and send the first protocol L2TP packet to the LAC-U.

Preferably, after the LAC-U receives the first L2TP protocol packet fed back by the BNG/vBNG-C according to the PPPoE protocol packet, and forwards the first L2TP protocol packet to the LNS-U, The method also includes:

sending, by the LNS-U, the first L2TP protocol packet to the BNG/vBNG-C;

The BNG/vBNG-C constructs a second L2TP protocol packet according to the first L2TP protocol packet, and sends the second L2TP protocol packet to the LNS-U;

The LNS-U sends the second L2TP protocol packet to the LAC-U.

A system for separating L2TP protocol control and forwarding provided according to an embodiment of the present invention includes: LAC-U, LNS-U, and BNG/vBNG-C;

The LAC-U is configured to forward the PPPoE protocol message sent by the user terminal to the BNG/vBNG-C, and receive the PPPoE protocol message fed back by the BNG/vBNG-C according to the PPPoE protocol message and carry the LNS-U. the first L2TP protocol packet of the IP address, forward the first L2TP protocol packet to the LNS-U, and receive the second L2TP protocol packet fed back by the LNS-U according to the first L2TP protocol packet , and establishes an L2TP tunnel and session with the LNS-U according to the second L2TP protocol message;

The LNS-U is configured to receive the BNG/vBNG-C and construct a second L2TP protocol packet according to the first L2TP protocol packet sent by the LAC-U, and convert the second L2TP protocol packet into the second L2TP protocol packet. forwarded to the LAC-U;

The BNG/vBNG-C is configured to construct the first L2TP protocol message according to the PPPoE protocol message, and send the first protocol L2TP message to the LAC-U, and according to the first L2TP message An L2TP protocol packet constructs a second L2TP protocol packet, and sends the second L2TP protocol packet to the LNS-U.

Preferably, the LAC-U is also used for:

In the case of receiving the data forwarding flow sent by the user terminal, sending the data forwarding flow to the LNS-U;

In the case of receiving the control packet sent by the user terminal, the control packet is forwarded to the BNG/vBNG-C via the LNS-U, so that the BNG/vBNG-C can perform session negotiation and address allocation , and deliver user entries to the LNS-U after session negotiation.

Preferably, the BNG/vBNG-C is specifically configured to determine whether the user terminal is an L2TP terminal according to the PPPoE protocol packet, and if the determination result is yes, construct the first L2TP protocol packet, and sending the first protocol L2TP message to the LAC-U.

According to an embodiment of the present invention, a device for separating L2TP protocol control and forwarding is provided, the device includes: a processor, and a memory coupled to the processor; the memory stores data that can be stored on the processor The running L2TP protocol control and forwarding separation program, when the L2TP protocol control and forwarding separation program is executed by the processor, implements the steps of the method for the L2TP protocol control and forwarding separation provided according to the embodiment of the present invention.

According to a computer storage medium provided by an embodiment of the present invention, a program for separating L2TP protocol control and forwarding is stored, and when the program for separating L2TP protocol control and forwarding is executed by a processor, the L2TP protocol control provided according to the embodiment of the present invention is implemented. Steps of a method separate from forwarding.

According to the solution provided by the embodiments of the present invention, the decoupling of L2TP user access forwarding and control is realized, and in the BNG/vBNG scenario where control and forwarding are separated, the separation of L2TP protocol control and forwarding is realized, and the L2TP protocol processing control plane realizes NFV Cloudization, user carrying capacity and redundant backup are enhanced.

Description of drawings

1 is a flowchart of a method for separating L2TP protocol control and forwarding according to an embodiment of the present invention;

2 is a schematic diagram of a system for separating L2TP protocol control and forwarding according to an embodiment of the present invention;

3 is a structural diagram of a networking scene diagram 1 provided by an embodiment of the present invention;

4 is a structural diagram of the second device networking scenario provided by an embodiment of the present invention;

5 is a top-level flowchart of L2TP user access protocol control and forwarding provided by an embodiment of the present invention;

6 is a detailed sequence diagram of an implementation provided by an embodiment of the present invention;

7 is a diagram of core components of an L2TP control and forwarding separation system according to an embodiment of the present invention;

FIG. 8 is a flowchart of L2TP user access protocol control and forwarding provided by an embodiment of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments described below are only used to illustrate and explain the present invention, but not to limit the present invention.

FIG. 1 is a flowchart of a method for separating L2TP protocol control and forwarding provided by an embodiment of the present invention, as shown in FIG. 1 , including:

Step S101: the LAC-U receives the PPPoE protocol packet sent by the user terminal, and forwards the PPPoE protocol packet to the BNG/vBNG-C;

Step S102: the LAC-U receives the first L2TP protocol packet fed back by the BNG/vBNG-C according to the PPPoE protocol packet, and forwards the first L2TP protocol packet to the LNS-U, wherein, The first L2TP protocol packet carries the IP address of the LNS-U;

Step S103: The LAC-U receives the second L2TP protocol message fed back by the LNS-U according to the first L2TP protocol message, and establishes a communication with the LNS-U according to the second L2TP protocol message. between L2TP tunnels and sessions.

Wherein, after the LAC-U establishes the L2TP tunnel and session with the LNS-U according to the second L2TP protocol message, the method further includes: the LAC-U forwards the data after receiving the data sent by the user terminal. In the case of flow, the LAC-U sends the data forwarding flow to the LNS-U; when the LAC-U receives the control message sent by the user terminal, the LAC-U sends the control message via the LNS-U It is forwarded to the BNG/vBNG-C, so that the BNG/vBNG-C can perform session negotiation and address allocation, and deliver a user entry to the LNS-U after the session negotiation.

Wherein, after the LAC-U receives the PPPoE protocol packet sent by the user terminal and forwards the PPPoE protocol packet to the BNG/vBNG-C, it further includes: the BNG/vBNG-C according to the PPPoE protocol packet Determine whether the user terminal is an L2TP terminal; if the determination result is yes, construct the first L2TP protocol packet, and send the first protocol L2TP packet to the LAC-U.

Wherein, after the LAC-U receives the first L2TP protocol packet fed back by the BNG/vBNG-C according to the PPPoE protocol packet, and forwards the first L2TP protocol packet to the LNS-U, the The method further includes: the LNS-U sends the first L2TP protocol message to the BNG/vBNG-C; the BNG/vBNG-C constructs a second L2TP protocol according to the first L2TP protocol message message, and send the second L2TP protocol message to the LNS-U; the LNS-U sends the second L2TP protocol message to the LAC-U.

FIG. 2 is a schematic diagram of a system for separating L2TP protocol control and forwarding according to an embodiment of the present invention. As shown in FIG. 2 , it includes: LAC-U, LNS-U, and BNG/vBNG-C; In order to receive the first L2TP protocol carrying the IP address of the LNS-U fed back by the BNG/vBNG-C according to the PPPoE protocol message by forwarding the PPPoE protocol message sent by the user terminal to the BNG/vBNG-C message, forward the first L2TP protocol message to the LNS-U, and receive the second L2TP protocol message fed back by the LNS-U according to the first L2TP The L2TP protocol message establishes an L2TP tunnel and session with the LNS-U; the LNS-U is configured to receive the first L2TP protocol message sent by the BNG/vBNG-C according to the LAC-U The BNG/vBNG-C is used to construct the first L2TP according to the PPPoE protocol message protocol packet, send the first protocol L2TP packet to the LAC-U, construct a second L2TP protocol packet according to the first L2TP protocol packet, and send the second L2TP protocol packet sent to the LNS-U.

Wherein, the LAC-U is further configured to: in the case of receiving the data forwarding flow sent by the user terminal, send the data forwarding flow to the LNS-U; after receiving the control message sent by the user terminal In this case, the control packet is forwarded to the BNG/vBNG-C via the LNS-U, so that the BNG/vBNG-C can perform session negotiation and address allocation, and report to the LNS- U delivers user entries.

The BNG/vBNG-C is specifically configured to determine whether the user terminal is an L2TP terminal according to the PPPoE protocol packet, and if the determination result is yes, construct the first L2TP protocol packet, and Send the first protocol L2TP message to the LAC-U.

An embodiment of the present invention provides a device for separating L2TP protocol control and forwarding. The device includes: a processor, and a memory coupled to the processor; the memory stores data that can be executed on the processor. The L2TP protocol control and forwarding separation program, when the L2TP protocol control and forwarding separation program is executed by the processor, implements the steps of the L2TP protocol control and forwarding separation method provided by the embodiment of the present invention.

A computer storage medium provided by an embodiment of the present invention stores a program for separating L2TP protocol control and forwarding, and when the program for separating L2TP protocol control and forwarding is executed by a processor, it implements the L2TP protocol control and forwarding provided according to the embodiment of the present invention. Steps of forwarding separation method.

In the embodiment of the present invention, in the BNG environment where control and forwarding are separated, the L2TP protocol control plane adopts X86 server virtualization to realize powerful cloud computing capabilities, and can dynamically expand and shrink resources according to the load conditions of user access, so as to achieve The effect of improving resource utilization and implementing redundant backup of L2TP control plane components breaks through the bottleneck of traditional BNG L2TP user access. At the same time, the L2TP forwarding plane adopts traditional high-performance forwarding hardware devices, which can avoid the weakness of the current X86 server's poor forwarding capability.

Fig. 3 is a structural diagram of Fig. 1 of a networking scenario provided by an embodiment of the present invention. As shown in Fig. 3, the included network elements and network modules include user equipment, BNG/vBNG-C, BNG/vBNG-UBNG/vBNG-U (Broadcast Network Gateway/Virtual Broadcast Network Gateway-User Plane, broadband network gateway/virtual broadband network gateway-forwarding plane);, AAA (authentication, authorization, billing) module, access network; BNG/vBNG-C consists of multiple Components, including: MP (Management Process, management processing) components, PP (Protocol Process, protocol processing) components, L2TP components, LB (Load Balance, load sharing) components; BNG/vBNG-U is composed of LAC-U and LNS- U composition.

The user equipment includes RG (Residential Gateway, residential gateway), CPE (Customer PremiseEquipment, user side equipment), PC (Personal Computer, personal computer), handheld terminal and the like.

The BNG/vBNG-C module includes the control plane of the BNG and the control plane of the vBNG, mainly for protocol negotiation, user authentication, access control, and user management of L2TP user access. The BNG/vBNG-U module includes the forwarding plane of BNG and the forwarding plane of vBNG. It is divided into LAC-U and LNS-U, which communicate with each other through the L3 network. It is mainly responsible for the forwarding of L2TP user traffic and the execution of user-related traffic policies.

As shown in FIG. 4 , in the processing device and system involved in the processing method for separating L2TP protocol control and forwarding according to the present invention, the LAC-U and the LNS-U may also have their own independent BNG/vBNG-C control planes. They are BNG/vBNG-C-1 and BNG/vBNG-C-2, respectively.

FIG. 5 is a top-level flowchart of L2TP user access protocol control and forwarding provided by an embodiment of the present invention, as shown in FIG. 5 , including the following steps:

In the first step, the LAC-U receives the PPPoE protocol packet sent by the user terminal, and encapsulates the packet in a VxLAN (Virtual Extensible LAN) tunnel and forwards it to the LB load balancing component of the BNG/vBNG-C;

In the second step, after receiving the PPPoE protocol packet, the BNG/vBNG-C LB sends it to each PP component according to a certain load sharing policy, and the PP component processes the PPPoE protocol packet;

In the third step, the PP component determines that the user is an L2TP user according to the user access domain name or the AAA authorization result obtained by the LCP (Link Control Protocol) message of PPPoE, and then notifies the L2TP component to perform protocol processing. Components can be deployed as load sharing (more than 2, fully shared) or active/standby mode (2 components, one active and one standby);

In the fourth step, the L2TP component searches for the corresponding LNS address according to the local L2TP-related configuration information, initiates the negotiation processing of the LAC-LNS tunnel and session, and constructs the L2TP protocol packet, and encapsulates the packet in the VxLAN through the LB component. It is sent to LAC-U in the tunnel, and the destination IP of the L2TP tunnel is LNS-U;

Step 5: LAC-U receives the control packet sent by LB. The control packet will carry the tunnel destination IP and VPN (Virtual Private Network, virtual private network) information, and LAC-U parses the tunnel destination address and VPN from it. The information is forwarded to LNS-U according to the IP address and VPN route check;

The sixth step, after receiving the L2TP protocol packet, the LNS-U encapsulates the VxLAN tunnel and sends it to the LB component of the BNG/vBNG-C;

In the seventh step, the BNG/vBNG-C sends the packet to the L2TP component, performs L2TP protocol processing, constructs the L2TP protocol packet, and encapsulates the packet in the VxLAN tunnel through the LB component and sends it to the LNS-U;

In the eighth step, the LNS-U receives the control packet (L2TP protocol packet) sent by the LB, parses the tunnel destination address and VPN information, and forwards it to the LAC-U according to the IP address and VPN route;

The ninth step, after the L2TP tunnel and session between LAC and LNS are established, BNG/vBNG-C sends the tunnel and session information to LAC-U and LNS-U through Openflow, and completes L2TP between LAC-U and LNS-U The establishment of the forwarding channel. The user terminal directly conducts PPP (Point to Point Protocol) negotiation with the LNS, and the LNS-U sends the user PPP negotiation packet to the LB of the BNG/vBNG-C through the VxLAN channel, and then the L2TP component performs PPP negotiation and address After the PPP session negotiation is completed, the BNG/vBNG-C delivers user entries to the LNS-U through Openflow.

FIG. 6 is a refinement sequence diagram of an implementation provided by an embodiment of the present invention. As shown in FIG. 6 , refinement steps of the steps described below are included.

The first step includes:

101, the user terminal sends a PPPoE dial-up request, the message is sent from the LAC-U to the BNG/vBNG-C control plane, and the PP component determines that the user is an L2TP user according to the domain name or AAA authorization result carried in the PPP LCP negotiation message;

The second step includes:

201, the L2TP component of the BNG/vBNG-C control plane constructs the L2TP protocol packet, and sends it to the corresponding LAC-U through the VxLAN channel;

202. After receiving the L2TP protocol packet, the LAC-U sends the L2TP protocol packet to the corresponding LNS-U according to the route;

203. After receiving the L2TP protocol packet, the LNS-U sends it to the BNG/vBNG-C control plane for processing;

204. After receiving the L2TP protocol packet, the BNG/vBNG-C control plane sends it to the L2TP component for processing. The L2TP component constructs a new L2TP protocol packet according to the L2TP-related configuration information configured on the BNG/vBNG-C control plane, and then sends it to the L2TP protocol packet. LNS-U;

205. After receiving the L2TP protocol packet, the LNS-U sends the L2TP protocol packet to the corresponding LAC-U according to the route;

206. The L2TP tunnel and session control packet negotiation is completed between the LAC and the LNS, the BNG/vBNG-C delivers the tunnel and session entries through openflow, and the endpoints of the tunnel are established on the LAC-U and the LNS-U;

The third step includes:

301. The user terminal sends a PPP LCP negotiation packet to the LAC-U, and the LAC-U encapsulates the L2TP tunnel header according to the local L2TP user entry and sends it to the LNS-U;

302. After receiving the PPP LCP negotiation packet, the LNS-U sends it to the BNG/vBNG-C control plane;

303. The BNG/vBNG-C control plane sends the PPP LCP negotiation message to the L2TP component, and the L2TP component completes the PPPLCP negotiation, and completes the NCP (Network Control Protocol, Network Control Protocol) negotiation with the user terminal, and assigns an internal address to the user. The BNG/vBNG-C control plane delivers user entries to the LNS-U through openflow;

304. After the user data forwarding message reaches the LAC-U, the L2TP tunnel is directly encapsulated and forwarded to the LNS-U, and the data forwarding message does not need to be sent to the BNG/vBNG-C control plane for processing;

Fig. 7 is a diagram of the core components of an L2TP control and forwarding separation system according to an embodiment of the present invention. As shown in Fig. 7, S: L2TP service access processing group, for L2TP user access processing group; P: user access port, specifically include:

The L2TP processing components of the BNG/vBNG-C control plane are deployed as active and standby, and LAC-U1 and LAC-U2 are forwarding pools. First, the specific embodiments S1, S2, and S3 of S are defined: the L2TP user access processing group S1 includes two forwarding plane devices, namely LAC-U1 and LNS-U1, and also includes the control plane L2TP processing component L2TP1, The syntax is expressed as S1 (LAC-U1&P1, LNS-U1, L2TP1), and P1 is the user access port; the L2TP user access processing group S2 includes two forwarding plane devices, namely LAC-U2, LNS-U1, and It includes the control plane L2TP processing component L2TP1, and the syntax is expressed as S2 (LAC-U2&P2, LNS-U1, L2TP1); the L2TP user access processing group S3 includes two forwarding plane devices, namely LAC-U2 and LNS-U1, It also includes a control plane L2TP processing component L2TP2, and the syntax is expressed as S2 (LAC-U2&P2, LNS-U1, L2TP2);

Further, when LAC-U1 and LAC-U2 receive the user's L2TP access request at the same time, both forwarding planes will send the access request message to the BNG/vBNG-C control plane. The PP component of the BNG/vBNG-C control plane will select an active LAC-U1 for user access according to the configuration, and the active L2TP1 component will process the L2TP access protocol, and the L2TP1 component will choose to perform L2TP with LNS-U1 according to the configuration of the control plane. Tunnel and session negotiation, that is, execute S1 access processing group. The BNG/vBNG-C control plane will deliver L2TP user entries to LAC-U1 and LAC-U2 at the same time. The P1 port of LAC-U1 is the active port, and the P2 port of LAC-U2 is the standby port.

Furthermore, when the P1 port of LAC-U1 fails, the P2 port of LAC-U2 becomes the primary port, and the L2TP user traffic is sent from LAC-U2 to LNS-U1, and the subsequent access of L2TP users is made by LAC-U2. Send it to the BNG/vBNG-C control plane, that is, the L2TP user access processing group S2;

Further, when the L2TP1 processing component of the BNG/vBNG-C control plane fails, the standby L2TP2 component will take over, and the L2TP2 component will be responsible for subsequent L2TP protocol processing, that is, execute the L2TP user access processing group S3;

FIG. 8 is a flowchart of L2TP user access protocol control and forwarding provided by an embodiment of the present invention, as shown in FIG. 8 , including:

Step 1, LAC-U1 and LAC-U2 form a pool, and at the same time receive the PPPoE protocol message sent by the user terminal, encapsulate the message in the VxLAN tunnel and forward it to the LB component of the BNG/vBNG-C;

Step 2, the BNG/vBNG-C receives the PPPoE protocol message and sends it to the PP component for processing the PPPoE protocol message. The PP component selects the active LAC-U1 for user access according to the control plane configuration;

Step 3, the PP component determines that the user is an L2TP user, and notifies the main L2TP component to perform protocol processing;

In step 4, the L2TP component initiates negotiation processing of the tunnel and session from the LAC to the LNS, and constructs the L2TP protocol packet to establish the L2TP tunnel and session between the LAC-U1 and the LNS-U1. User data forwarding traffic is directly encapsulated L2TP headers from LAC-U1 to LNS-U1, and user dial-up control messages are sent to BNG/vBNG-C control plane;

Step 5, when the LAC-U1 access port fails, the user is accessed by the LAC-U2, and the control plane is still processed by the main L2TP component;

Step 6, when the main L2TP component of the BNG/vBNG-C control plane fails, the standby L2TP component takes over, and user services are not interrupted;

As described above, the BNG/vBNG control plane of the present invention processes L2TP control protocol packets by adding an L2TP protocol processing component (VM virtual machine). The L2TP protocol processing component can deploy multiple VMs to form active/standby or load sharing. The L2TP protocol processing component is responsible for the exchange of L2TP tunnels and session control packets. The endpoints of the tunnels are established on the BNG/vBNG forwarding plane. L2TP control protocol packets are identified by the BNG/vBNG forwarding plane and then sent to the L2TP protocol processing component of the control plane for processing, while L2TP data forwarding packets are directly encapsulated by the L2TP header on the BNG/vBNG forwarding plane for forwarding, and do not need to be forwarded to the control plane for processing . The L2TP protocol control plane stores L2TP user entries. When the BNG/vBNG forwarding plane is connected to the user port or the entire device fails, the control plane can perform a hot backup switchover of users and switch to the backup BNG/vBNG forwarding plane.

According to the solution provided by the embodiment of the present invention, the separation of L2TP user access protocol control and forwarding is realized, the L2TP protocol control plane adopts X86 general server, and the L2TP forwarding plane adopts traditional high-performance hardware, which not only improves the processing capability of the control plane, but also improves the The forwarding capability of the forwarding plane is guaranteed. The advantage of this technology is that it is self-adaptive and has no additional requirements for the surrounding network; the capacity of L2TP access users is improved, and the capacity can be automatically expanded and contracted. The forwarding plane still uses high-performance hardware, which can meet various L2TP application scenarios.

Although the present invention has been described in detail above, the present invention is not limited thereto, and various modifications can be made by those skilled in the art in accordance with the principles of the present invention. Therefore, all modifications made in accordance with the principles of the present invention should be understood as falling within the protection scope of the present invention.

Claims (9)

1. A method for separating L2TP protocol control and forwarding is characterized by comprising the following steps:

the LAC-U receives a PPPoE protocol message sent by a user terminal and forwards the PPPoE protocol message to a BNG/vBNG-C;

the LAC-U receives a first L2TP protocol message fed back by the BNG/vBNG-C according to the PPPoE protocol message, and forwards the first L2TP protocol message to the LNS-U, wherein the first L2TP protocol message carries the IP address of the LNS-U;

the LAC-U receives a second L2TP protocol message fed back by the LNS-U according to the first L2TP protocol message, and establishes an L2TP tunnel and a session with the LNS-U according to the second L2TP protocol message;

wherein the L2TP refers to a layer two tunneling protocol; the BNG/vBNG-C refers to a bandwidth network gateway/virtual bandwidth network gateway-control plane; the LAC-U refers to the L2TP access convergence point-forwarding plane; the LNS-U refers to the L2TP network server-forwarding plane.

2. The method of claim 1, wherein after the LAC-U establishes an L2TP tunnel and session with the LNS-U according to the second L2TP protocol packet, further comprising:

the LAC-U sends the data forwarding flow to the LNS-U under the condition of receiving the data forwarding flow sent by a user terminal;

and the LAC-U forwards the control message to the BNG/vBNG-C through the LNS-U under the condition of receiving the control message sent by the user terminal, so that the BNG/vBNG-C performs session negotiation and address allocation, and sends a user table entry to the LNS-U after the session negotiation.

3. The method of claim 1, wherein after the LAC-U receives a PPPoE protocol packet sent by the user equipment and forwards the PPPoE protocol packet to the BNG/vBNG-C, the method further comprises:

the BNG/vBNG-C judges whether the user terminal is an L2TP terminal or not according to the PPPoE protocol message;

and if so, constructing the first L2TP protocol message and sending the first protocol L2TP message to the LAC-U.

4. The method of claim 1, wherein after the LAC-U receives a first L2TP protocol packet fed back by the BNG/vBNG-C according to the PPPoE protocol packet and forwards the first L2TP protocol packet to the LNS-U, the method further comprises:

the LNS-U sends the first L2TP protocol message to the BNG/vBNG-C;

the BNG/vBNG-C constructs a second L2TP protocol message according to the first L2TP protocol message, and sends the second L2TP protocol message to the LNS-U;

and the LNS-U sends the second L2TP protocol message to the LAC-U.

5. A system for separating L2TP protocol control and forwarding, comprising: LAC-U, LNS-U and BNG/vBNG-C;

the LAC-U is configured to forward a PPPoE protocol packet sent by a user terminal to a BNG/vBNG-C, receive a first L2TP protocol packet carrying an IP address of the LNS-U and fed back by the BNG/vBNG-C according to the PPPoE protocol packet, forward the first L2TP protocol packet to the LNS-U, receive a second L2TP protocol packet fed back by the LNS-U according to the first L2TP protocol packet, and establish an L2TP tunnel and a session with the LNS-U according to the second L2TP protocol packet;

the LNS-U is configured to receive the first L2TP protocol packet sent by the BNG/vBNG-C according to the LAC-U, construct a second L2TP protocol packet, and forward the second L2TP protocol packet to the LAC-U;

the BNG/vBNG-C is configured to construct the first L2TP protocol packet according to the PPPoE protocol packet, send the first L2TP protocol packet to the LAC-U, construct the second L2TP protocol packet according to the first L2TP protocol packet, and send the second L2TP protocol packet to the LNS-U;

wherein the L2TP refers to a layer two tunneling protocol; the BNG/vBNG-C refers to a bandwidth network gateway/virtual bandwidth network gateway-control plane; the LAC-U refers to the L2TP access convergence point-forwarding plane; the LNS-U refers to the L2TP network server-forwarding plane.

6. The system of claim 5, wherein the LAC-U is further configured to:

under the condition of receiving a data forwarding stream sent by a user terminal, sending the data forwarding stream to the LNS-U;

and under the condition of receiving a control message sent by a user terminal, forwarding the control message to the BNG/vBNG-C through the LNS-U so that the BNG/vBNG-C can carry out session negotiation and address allocation, and issuing a user table entry to the LNS-U after the session negotiation.

7. The system according to claim 5, wherein said BNG/vBNG-C is specifically configured to determine whether said ue is an L2TP ue according to said PPPoE protocol packet, and if so, construct said first L2TP protocol packet, and send said first protocol L2TP packet to said LAC-U.

8. An L2TP protocol control and forwarding separation device, characterized in that the device comprises: a processor, and a memory coupled to the processor; the memory has stored thereon an L2TP protocol control and forwarding separation program executable on the processor, the L2TP protocol control and forwarding separation program when executed by the processor implementing the method of any of claims 1-4.

9. A computer storage medium, characterized in that the computer storage medium stores a L2TP protocol control and forwarding separation program, and the L2TP protocol control and forwarding separation program, when executed by a processor, implements the steps of the L2TP protocol control and forwarding separation method according to any one of claims 1 to 4.

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