WO2012149850A1

WO2012149850A1 - Vpn routing-based method, system, and router for establishing lsp

Info

Publication number: WO2012149850A1
Application number: PCT/CN2012/073484
Authority: WO
Inventors: 邓柱升
Original assignee: 华为技术有限公司
Priority date: 2011-08-03
Filing date: 2012-04-01
Publication date: 2012-11-08
Also published as: CN102355402A; CN102355402B

Abstract

Provided in the present invention are a method, system, and base station for establishing a label-switched path (LSP). A first provider edge router (PE) receives a notification message from a first evolved node base station (eNodeB). The notification message comprises an IP address of a second eNodeB. The first eNodeB and the second eNodeB are adjacent base stations. The first PE searches for a pre-established routing table on the basis of the IP address of the second eNodeB. The first PE acquires a routing table entry having the IP of the second eNodeB as a destination IP and having an entry of the second PE as a match for a next hop. The first PE establishes via a label distribution protocol an LSP connection to the second PE. As such, an LSP network connection is established between PEs respectively having a direct IP layer connection-relation to the adjacent base station.

Description

Method, system and router for establishing LSP based on VPN route

This application claims priority to Chinese Patent Application No. 201110221347. 5, entitled "Method, System and Router for Establishing LSP Based on VPN Routes", all of which are filed on August 3, 2011. The content is incorporated by reference in this application.

Technical field

The present invention relates to communication networks, and more particularly to a method, system and router for establishing an LSP based on VPN routes. Background technique

The wireless network has evolved from 3G (Third Generation) technology to LTE (Long Term Evolution) technology, and the network bandwidth has been greatly improved. Compared with 3G technology, LTE technology is also simplified in the network architecture, which is mainly reflected in the evolution of 3G based on ATM/TDM (Asynchronous Transfer Mode) (Time Division Multiplexing) ( A flat network of IP (Internet Protocol, a protocol interconnected between networks).

Figure 1 is a schematic diagram of an existing 3G network. In a 3G network, all NodeB (node base station) services are aggregated to the RNC (Radio Network Controller) through the ATM/TDM network.

2 is a schematic diagram of an existing LTE network. In an LTE network, the service of the eNodeB (evolved node base station) is aggregated to the S-GW/MME (Mobility Management Entity) (S1 service), and the service between the eNodeB and the eNodeB (X2 service) ). In the LTE technology, the X2 service is mainly used for transmitting data during handover when the terminal performs handover between adjacent base stations, which also means that there is only X2 demand between adjacent base stations and no X2 service interworking between non-adjacent base stations.

To implement the bearer of the Sl and X2 services of the eNodeB, a common method is to carry the bearer through the L3VPN (Layer 3 Virtual Private Network) technology, as shown in Figure 3. The interconnection between the eNodeB and the eNodeB, the eNodeB, and the S-GW/MME is implemented through an L3VPN (Layer 3 Virtual Private Network) network. The PE (Provider Edge)/POP (Point of Provision) node is the edge node where the L3VPN network is connected to the eNodeB and S-GW/MME. The PE node is connected to the eNodeB, and the POP node is connected to the S-GW/MME. A full mesh (full mesh) connection between PEs is built using L3VPN technology. With this prior art, the eNodeB can implement interworking with any S-GW/MME and eNodeB. The technical solution is based on the existing L3VPN technology in the industry and is simple to deploy. However, the inventors found during the research that the technology has the following two problems.

First, network security issues. As mentioned above, the X2 service only needs to be used between adjacent eNodeBs. Therefore, many operators currently do not want non-adjacent eNodeBs to communicate with each other from the perspective of security to prevent network attack problems caused by illegal eNodeB access. Because of the Full mesh connection, all eNodeBs are available. In terms of interoperability, the above-mentioned prior art cannot meet the security requirements.

Second, network scalability issues. The existing L3VPN technology is based on the ful l mesh connection. All PEs need to establish network connections. Therefore, N*(N-1) (N is the number of edge nodes in the L3VPN network) network connection needs to be established in the network. When the network size is large, too many network connections may cause scalability problems such as network device failure and operation and maintenance difficulties.

Summary of the invention

It is an object of the present invention to provide a solution to the network security and scalability issues described above.

The present invention provides a method of establishing an LSP in a first aspect. The method includes: a first operator edge router PE receives a notification message from a first evolved node base station eNodeB, where the notification message includes an IP address of a second eNodeB, where the first eNodeB and the second eNodeB belong to a neighboring base station; The first PE searches the pre-established routing table according to the IP address of the second eNodeB, and obtains an entry whose destination IP address is the IP address of the second eNodeB and whose next hop is the second PE as the matching routing entry. The first PE establishes a label switching path LSP with the second PE by using a label distribution protocol.

The present invention provides a carrier edge router PE in a second aspect. The PE includes: a memory, configured to store a routing table, and a notification message receiving module, configured to receive a notification message from the first eNodeB, where the message includes an IP address of the second NodeB, where the first eNodeB and the second eNodeB belong to a neighboring base station; a searching module, configured to search a routing table according to the IP address of the second eNodeB, and obtain an entry whose destination IP address is the IP address of the second eNodeB and the next hop is another PE as a matching routing entry. A connection establishment module is configured to establish an LSP with another PE through a label distribution protocol.

The present invention provides a network system in a third aspect. The system includes the PE of the second aspect and the other PE.

With the foregoing embodiment of the present invention, when a base station to which a PE is connected and a base station connected to another PE is a neighboring base station, an LSP connection is established between the two PEs. Otherwise, an LSP connection is not established between the PEs. An LSP connection is established only between PEs connected to neighboring base stations, which avoids interworking between non-adjacent base stations, can meet security requirements, and can reduce the number of network connections and improve network scalability. DRAWINGS

Specific embodiments of the present invention will now be described in more detail with reference to the accompanying drawings in which:

1 is a schematic diagram of an existing 3G network;

2 is a schematic diagram of an existing LTE network; Figure 3 is an existing method of carrying by L3VPN technology;

4 is a schematic diagram of a network architecture according to an embodiment of the present invention;

Figure 5 illustrates the process by which the eNodeBl discovers the eNodeB2 using the ANR protocol;

Figure 6 (a) and (b) are examples of VPN IPv4 routing tables;

Figure 7 is a block diagram showing the structure of a carrier edge router in accordance with an embodiment of the present invention. detailed description

4 is a schematic diagram of a network architecture in accordance with one embodiment of the present invention.

As shown in Figure 4, through the L3VPN (Layer 3 Virtual Private Network) network, the eNodeB is interconnected via PE and S-GW (Serving-Gateway)/匪 E (Mobility Management Entity). Specifically, PE1, PE2, and PE3 are edge nodes respectively connected to the eNodeB l, eNodeB2, and eNodeB3 in the L3VPN network. The IP subnet address of the link between the eNodeB1 and the PE1 is configured as, for example, 20. 1. 1. 0/24. Similarly, the IP subnet address of the link between the eNodeB2 and the PE2 is configured to be, for example, 20. 1. 2. 0/24; the IP subnet addresses of the link between the eNodeB 3 and the PE3 are respectively configured to be, for example, 20. 0/24. The POP node is an edge node directly connected to the L3VPN network and the S-GW/MME through the link.

Note that, in the initial phase of the networking, PEK PE2 and PE3 are only connected to the POP ( Label Switch Path), and no LSP connection is established between PEs.

According to the present embodiment, an LSP connection is dynamically established as needed between PEs having a direct link connection relationship with a base station having an adjacent relationship. This will be explained below.

First, the MP-BGP protocol (Multi-Protocol Border Gateway Protocol) is run on each PE to facilitate the diffusion or routing of PEs. The so-called diffusion means that the PE router distributes routing information to each PE router through MP-BGP sessions or using route reflection. In the case of an MP-BGP session, a BGP session is directly flooded between the PEs. In the case of a route reflection, the PE only needs to establish a BGP session with the POP. The MP-BGP protocol spreads the subnet IP address of each PE link to other PE nodes in the form of VPN IPv4 routes.

For example, PE1 and PE2 are used to establish a VPN IPv4 routing table as shown in Figure 6 (a) and (b). Each routing table includes several entries. Each routing entry includes { destination IP address, next hop}. Take the route advertisement process from PE2 to PE1 as an example. PE2 encapsulates the subnet IP address of the link to the eNodeB link to the MP-BGP route advertisement message. The route advertisement message includes the destination IP address. The address is 20. 1. 2. 0/24, and the next hop is PE2. After receiving the MP-BGP route advertisement message, PE1 establishes a route forwarding entry {20. 1. 2. 0/24, PE2} according to the destination IP address and the next hop information. As shown in Figure 6 (a), in PE1 Three routing entries are recorded in the routing table: {20. 1. 1. 0/24 , PE1}; {20. 1. 2. 0/24 , PE2}; {20. 1. 3. 0/24 , PE3}. As shown in Figure 6 (b), three routing entries are recorded in the routing table of PE2: {20. 1. 1. 0/24, PE1}; {20. 1. 2. 0/24, PE2} {20. 1. 3. 0/24, PE3}.

The eNodeB1 discovers its neighboring eNodeB2 through the ANR (Automatic Neighbour Relation) protocol, and sends the IP address information of the neighboring eNodeB2 to the PE1 by a notification message 20. 2. 2. 2/24. There are several ways to notify a message depending on the protocol.

Then, PE1 searches the VPN IPv4 routing table in PE1 according to the IP address and matches the IP address of the eNodeB2 to the destination IP address and the next hop as the entry of PE2, that is, {20. 1. 2. 0/24, PE2} The entry is such that PE1 knows that eNodeB 2 and PE2 are directly connected through the link. PE1 determines that an LSP needs to be established with PE2 and triggers the LDP (Label Distribution Protocol) protocol to establish the LSP. Of course, LSPs can also be established through other label distribution protocols, such as the RSVP-TE protocol.

In the above example, the destination IP address in the {20. 1. 2. 0/24, PE2} routing entry is the IP address of the eNodeB2. Further, the destination IP address may be the host IP address of the eNodeB2 or the subnet IP address of the link to which the eNodeB2 is connected.

The foregoing describes the process by which PE1 determines the need to establish an LSP with PE2 based on the IP address of the neighboring base station _e NodeB2 from the eNodeB1. Similarly, in the opposite direction, PE2 can determine that an LSP needs to be established with PE1 through a similar procedure, and triggers LDP to establish the LSP.

In the LTE technology, multiple methods can be used to determine whether two base stations are adjacent (i.e., there is an X2 service requirement between two base stations). The first method is to manage the plan through the network. In the network specification stage, the network administrator determines whether the two base stations are adjacent according to the static plan. The advantage of this method is simplicity. The second method is that the base station automatically discovers its neighboring base stations through a protocol, and the method can accurately determine neighbor base station information and reduce the complexity of network management. 3GPP defines the ANR (Automatic Neighbour Relation) protocol for automatic discovery of neighboring base stations.

Figure 5 illustrates the process by which the eNodeBl discovers the eNodeB2 using the ANR protocol.

As shown in FIG. 5, in step S1, the eNodeB1 finds that it is an adjacent node with the eNodeB2 by interacting with a user equipment UE. Specifically, the UE detects all eNodeB devices that can be connected by wireless signals, i.e., eNodeB 1 and eNodeB 2 in the figure. The UE obtains the corresponding eNodeB identifier (eNodeB identifier) from the eNodeB 2, and then the UE sends the eNodeB ID to the eNodeB 1 as a notification message.

In step S2, the eNodeB1 obtains the IP address of the eNodeB2 through the MME as 20. 1. 2. 2/24.

In step S3, the eNodeB1 notifies the PE1 of its own IP address (20. 1. 1. 2/24) and the IP address of the neighboring eNodeB2.

Through the above three steps, PE1 knows that it is connected to the eNodeB1 and the eNodeB2 with an IP address of 20. 1. 2. 2/24 Adjacent.

FIG. 7 is a structural diagram of a carrier edge router according to an embodiment of the present invention. The operator edge router is used to implement the function of the PE1 in the foregoing method embodiment. As shown in FIG. 7, the operator edge router 700 is an edge node connected to the eNodeB1 by the virtual private network, and includes a memory 708, which stores a routing table, where the routing table includes the IP address of the eNodeB2 and the next hop. The entry for PE2. PE2 is an edge node where the virtual private network and the eNodeB2 are connected through a link. Provider edge router 700 further includes a notification message receiving module 702 receives the notification message from the eNodeBl, wherein the message includes the IP address of the _e NodeB2, wherein the neighboring base station belonging eNodeBl and eNodeB2; searching module 704, in accordance with the message of IP eNodeB2 The address is found in the routing table, and the entry with the destination IP address being the IP address of the eN ₀ deB2 and the next hop being the PE2 is used as the matching routing entry. The connection establishing module 706 establishes the LSP connection with the PE2 through the label distribution protocol.

Through the above process, an LSP network connection is established between PE1 and PE2. Because there is no neighboring base station between PE1 and PE3, the LSP network connection is not established. Therefore, the security requirements are met, and the scalability of the network is improved.

Although the present invention has been described in detail in connection with the L3VPN network, the present invention is not limited thereto, and can be applied to other networks such as an L2VPN network or a similar virtual private network. In addition, the routing protocol running on the PE is not limited to the MP-BGP protocol, and other similar routing protocols can be used. The PE and the eNodeB1 can be connected directly through the physical link or through the Layer 2 network.

It is apparent that there are many variations to the invention described herein, and such variations are not to be construed as a departure from the spirit and scope of the invention. Accordingly, all changes that are obvious to those skilled in the art are intended to be included within the scope of the appended claims.

Claims

Claim

A method of establishing an LSP, the method comprising:

The first carrier edge router PE receives a notification message from the first evolved node base station eNodeB, where the notification message includes an IP address of the second eNodeB, and the first eNodeB and the second eNodeB belong to the neighboring base station;

The first PE searches the pre-established routing table according to the IP address of the second eNodeB, and obtains an entry whose destination IP address is the IP address of the second eNodeB and the next hop is the second PE as the matching routing entry.

The first PE establishes a label switching path LSP with the second PE by using a label distribution protocol.

2. The method according to claim 1, wherein the destination IP address in the matched routing entry is a host IP address of the second eNodeB or a subnet IP address of the link to which the second eNodeB is connected.

The method according to claim 1 or 2, wherein the method comprises the second PE encapsulating the IP address of the second eNodeB with a route advertisement message, the destination IP address of the route advertisement message being the second eNodeB The IP address and the next hop are the second PE. After receiving the route advertisement message, the first PE establishes a route forwarding entry according to the destination IP address and the next hop information, thereby establishing the routing table.

4. The method according to one of claims 1-3, wherein the method comprises the step of the first eNodeB discovering that the first eNodeB and the second eNodeB belong to a neighboring base station.

5. The method according to claim 4, wherein the step of the first eNodeB discovering that the first eNodeB and the second eNodeB belong to the neighboring base station comprises:

The first eNodeB finds that it is a neighboring node with the second eNodeB by interacting with the user equipment UE; the first eNodeB acquires the IP address of the second eNodeB by using the mobility management entity MME.

A carrier edge router PE, the PE includes:

a memory for storing a routing table;

a notification message receiving module, configured to receive a notification message from the first eNodeB, where the message includes an IP address of the second eNodeB, where the first eNodeB and the second eNodeB belong to the neighboring base station;

a locating module, configured to search the routing table according to the IP address of the second eNodeB, and obtain an entry with the destination IP address being the IP address of the second eNodeB and the next hop being the other PE as the matching routing entry;

A connection establishment module is configured to establish an LSP with another PE through a label distribution protocol.

7. The carrier edge router of claim 6, wherein the first eNodeB discovers, by the ANR protocol, that the first eNodeB and the second eNodeB belong to neighboring base stations.

8. The operator edge router according to claim 7, wherein the first eNodeB, by interacting with the UE, finds that the first eNodeB and the second eNodeB belong to the neighboring base station.

9. The operator edge router according to any one of claims 6-8, wherein the first eNodeB obtains the IP address of the second eNodeB through the mobility management entity MME.

10. A network system comprising the PE of one of claims 6-8 and the other PE.