KR20070064703A - How to support the LOS service for each L2XP network subscriber using CR-LSP - Google Patents

Abstract

The present invention relates to a L2VPN subscriber-specific QoS support method using a CR-LSP, and provides a L2VPN subscriber-specific QoS support method using a CR-LSP capable of guaranteeing a subscriber-specific QoS. To this end, the present invention provides a generation step of generating a subscriber-specific CR-LSP by specifying connection characteristics such as path, bandwidth, priority, etc. according to a desired QoS for packet transmission between subscribers in the MPLS L2VPN network; And a mapping step of mapping the subscriber L2 interface, the PW information in the MPLS network, and the connection information of the generated CR-LSP. By the above configuration, the present invention can provide a separate CR-LSP for each subscriber, and thus, there is an effect of guaranteeing QoS for each subscriber.

Description

Method for supporting QoS for L2VPN subscriber using CR-LSP}

1 is a block diagram illustrating a partial configuration of a PE for a method for supporting QoS of each L2VPN subscriber using CR-LSP according to an embodiment of the present invention.

2 is a flowchart illustrating a method for supporting QoS of each L2VPN subscriber using CR-LSP according to an embodiment of the present invention.

3 is a block diagram of an L2PVN service network constructed by the method of FIG.

4 is a block diagram of a conventional L2VPN service network.

5 is a flowchart illustrating a conventional L2VPN service setting method.

Explanation of symbols on the main parts of the drawings

10: PE 110: VPN control unit

120: MPLS signaling processor 130: forwarding processor

132: forwarding table 310 ~ 316: CE

320 ~ 326: PE 332 ~ 336: LSR

340 ~ 342: CR-LSP 350 ~ 356: Subscriber Line

The present invention relates to a method for supporting Layer 2 Virtual Private Network (L2VPN) Quality of Service (QoS) by subscriber using a Constraint-based Routing LSP (CR-LSP), and in particular, a tunnel between provision edges (PEs) for packet transmission. The present invention relates to a L2VPN subscriber-specific QoS support method using a CR-LSP capable of guaranteeing QoS for each subscriber by forming a CR-LSP.

In general, a virtual private network (VPN) is a communication network that is constructed on a public telephone network so that a user can use it as if it is a private private network or a private network. It allows you to define your own network configuration and build an arbitrary telephone numbering system.

In addition, the VPN service provides a user with a high level of network management function in a public communication network, for example, providing services such as extension dials, charges for each extension, and creation of various statistical reports between establishments distributed in an enterprise.

These VPN services are mainly based on high-security IP tunneling, but recently, because QoS is difficult to support, scalability due to mesh structure is limited, and installation and management are difficult. Highly scalable and differentiated QoS support is possible, and service and operation management is being replaced by MPLS based, which is much simpler than other structures.

Meanwhile, the structure for providing a VPN service includes an L2VPN structure using Layer 2 (L2) and an L3VPN structure using Layer 3 (L3; Layer 3). Can be classified according to.

In other words, L3VPN service is provided if routing PE is equipped with routing protocols such as BGP (Boarder Gateway Protocol), and if there is no such function, L2 can be serviced as a low-cost device that does not require routing function. Provide VPN service.

In particular, the L2VPN structure is more suitable when CE (Customer Edge) provides Layer 2 services such as ATM, Frame Relay, and Ethernet.

4 is a configuration diagram of a conventional L2VPN service network.

L2VPN service network is composed of CE (410 ~ 416) located at the edge (edge) of the subscriber network, PE (420 ~ 422) connecting the L2VPN service network and the subscriber network.

Since CE (410 ~ 416) only needs to establish L2 connection to PE (420 ~ 422) to register to a specific VPN, it does not need MPLS signaling function or routing function for VPN management. Connection is also possible.

The PEs 420 to 422 establish an LSP connection using a label distribution protocol (LDP). The PEs 420 to 422 generate LSPs according to routing information collected from route information in a network, and forward the set LSP information therein. And store it in the forwarding table (not shown).

In addition, the PEs 420 to 422 generate a physical port as a logical interface, that is, a general interface (L3 interface) for processing Layer 3 (IP) and an L2 interface for processing Layer 2. By this L2 interface, the PE 420 to 422 establishes a subscriber connection circuit with the CE 410 to 416.

As such, a tunnel by an LSP connection is connected between the PEs 420 to 422 located at the end of the L2VPN service network. At this time, a subscriber's virtual wire (PW) is established and the connection information is PE (420). Exchange and management using the LDP signaling protocol.

By such a configuration, the PE 420 adds a PW label to packets introduced from the CEs 410 to 412 through the L2 interface using the PW label information exchanged through signaling, and transmits the PW label through the LSP tunnel. .

On the other hand, the peer PE 422 receiving the PW-labeled packet forwards the packet to the destination L2 subscriber by identifying the output L2 interface by the PW label.

5 is a flowchart illustrating a conventional L2VPN service setting method.

The setting method for the L2VPN service in the PE 420 of the MPLS first establishes subscriber connection lines 450 to 456 using the L2 interface (step S501).

Next, in the MPLS L2VPN service network, the PW is set for the function of the virtual connection line 440 between the PEs 420 to 422 between the two ends. The label of the PW is set as the LDP signaling protocol between the PEs 420 to 422. It is exchanged and managed using (step S502).

The subscriber L2 interface configured as described above and the PW information in the MPLS L2VPN service network are mapped to each other, and the corresponding mapping information is transmitted to a forwarding processor (not shown) inside the PEs 420 to 422, and a forwarding processor (not shown). Writes the LSP connection information to the forwarding table (not shown) together with the L2 interface and the PW label information as the mapping information (step S503).

As such, when all settings are completed at both ends of the PEs 420 to 422, the packet flowing into the PE 420 through the subscriber L2 interface is sent to the other side PE 422 through the LSP according to the mapping information recorded in the forwarding table (not shown). ), And then the corresponding L2 interface is identified by the forwarding table (not shown) of the peer PE 422 and transmitted to the destination L2 subscriber.

However, in the conventional MPLS L2VPN service, since the PW-labeled subscriber packet is forwarded using the LSP connection by LDP signaling between the PEs at both ends, it is difficult to guarantee the QoS of the subscriber packet and even in case of different VPN services. If both ends of the PE are the same, since the LSP uses the same connection, there is a problem in that QoS cannot be guaranteed for each subscriber.

The present invention has been proposed to solve the above problems, and provides a QoS support method for each L2VPN subscriber using CR-LSP that can guarantee QoS for each subscriber by forming a tunnel between PEs for packet transmission as a CR-LSP. It aims to do it.

The present invention for achieving the above object is a generation step of generating a subscriber-specific CR-LSP by specifying the connection characteristics such as path, bandwidth, priority, etc. according to the desired QoS for packet transmission between subscribers of the MPLS L2VPN network between PEs Wow; And a mapping step of mapping the subscriber L2 interface, the PW information in the MPLS network, and the connection information of the generated CR-LSP.

Preferably, the mapping may include a storing step of storing the subscriber L2 interface, the PW information, and the CR-LSP connection information in a forwarding table of a forwarding processor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a partial configuration of a PE for a method for supporting QoS of each L2VPN subscriber using a CR-LSP according to an embodiment of the present invention.

The PE 10 sets up a subscriber connection line and maps the VPN control unit 110 to the PW label according to the CR-LSP connection information, the MPLS signaling processor 120 generating the CR-LSP according to the collected routing information, Forwarding processing unit 130 for storing the mapping information to process the transmission and reception of the packet.

The VPN controller 110 establishes a subscriber connection line for connecting to the subscriber network through the L2 interface, transmits and receives routing information with the peer PE router, and selects CR- for a specific subscriber to be used for packet mapping according to a system operator's selection. The LSP information is requested to the MPLS signaling processor 120, the QoS parameters corresponding to the QoS policy are mapped according to the request result, and the transmission information is transmitted to the forwarding processor 130.

The MPLS signaling processor 120 generates a CR-LSP that satisfies a specific QoS by using the MPLS signaling protocols CR-LDP and RSVP-TE (Resource ReserVation Protocol-Traffic Engineering), and CR-LSP of the VPN controller 110. After retrieving the CR-LSP currently generated according to the information request, it outputs the identified CR-LSP connection status and its status information to the VPN controller 110 using the CR-LSP information.

The forwarding processor 130 stores the mapping information of the VPN controller 110 in the forwarding table 132 and forwards the packet received through the L2 interface to the MPLS L2VPN network or the corresponding CE according to the mapping information of the forwarding table 132. do.

Hereinafter, a method for supporting QoS of each L2VPN subscriber using CR-LSP according to an embodiment of the present invention will be described with reference to FIGS. 2 to 3.

FIG. 2 is a flowchart illustrating a method for supporting QoS of each L2VPN subscriber using CR-LSP according to an embodiment of the present invention, and FIG. 3 is a configuration diagram of an L2PVN service network constructed by the method of FIG.

First, in step S201, when the subscriber connection line is established using the L2 interface, a method of supporting QoS for each L2VPN subscriber using the CR-LSP is disclosed.

That is, each of the PEs 320 to 322 sets up each subscriber connection line 350 to 356 using the corresponding CEs 310 to 316 and the L2 interface. 3, the CE 312 connected to the PE 320 and the CE 314 connected to the PE 322 are illustrated as subscriber 1 as the same subscriber network, and the CE ( 310 and CE 316 connected to PE 322 are shown as subscriber 2 as the same subscriber network.

More specifically, the VPN controller 110 inside each PE 320 to 322 establishes a subscriber connection line 350 to 356 with the CEs 310 to 316 of each subscriber network through the L2 interface.

In step S202, a virtual connection line PW between PEs is set.

More specifically, in the MPLS L2VPN service network, a PW for virtual connection line function between the PEs 320 to 322 of both ends is set, and the label of the PW set as described above is a VPN control unit inside each PE 320 to 322. 110 is exchanged and managed between the PEs 320 to 322 using the CR-LDP signaling protocol.

In step S203, CR-LSP for inter-PE transmission is set.

That is, the subscriber-specific CR-LSP (340-342) is generated by designating connection characteristics such as path, bandwidth, priority, etc. according to the desired QoS for packet transmission between subscribers (320-322) of the MPLS L2VPN network.

More specifically, the MPLS signaling processor 120 inside each PE 320 to 322 generates a CR-LSP for each subscriber that satisfies a specific QoS by using the CR-LDP and RSVP-TE.

The CR-LSPs 340 to 342 configured as described above are configured for each subscriber. For example, as shown in FIG. 3, the LSR (Label) inside the MPLS network from the PE 320 which is a label switched edge router (LER). The CR-LSP 340, which is connected to the PE 322 via the Switched Router 332 and the LSR 336, forms a tunnel for the subscriber 1 and connects the LSR 332 with the LSR 332 inside the MPLS network from the PE 320. The CR-LSP 342, which is connected to the PE 322 via the LSR 334 and the LSR 336, forms a tunnel for subscriber 2.

In this way, since each subscriber uses a separate CR-LSP even when using the same PE, QoS can be guaranteed for each subscriber.

In step S204, mapping according to the association between the subscriber connection line and the virtual connection line is performed.

More specifically, the VPN controller 110 inside each PE 320 to 322 maps the subscriber L2 interface configured as in step S201 and the PW information in the MPLS L2VPN service network configured as in step S202 to be related to each other. The corresponding mapping information is transmitted to the forwarding processor 130 inside the PEs 320 to 322.

At this time, when the VPN control unit 110 requests the CR-LSP information to the MPLS signaling processing unit 120, and receives the CR-LSP information generated as in step S203 from the MPLS signaling processing unit 120, the VPN control unit 110 again. ) Can use different CR-LSP for each subscriber by mapping subscriber L2 interface and PW information in MPLS network.

Here, the forwarding processor 130 stores the CR-LSP connection information together with the subscriber L2 interface and the PW label information in the forwarding table 132.

As such, when all the settings are completed at both ends of the PE 320 to 322, the packet flowing into the PE 320 through the subscriber connection line 350 to 352 by the subscriber L2 interface is forwarded to the forwarding table 132 of the forwarding processor 130. ) Is delivered to the peer PE 322 through the subscriber-specific CR-LSPs 340 to 342 according to the mapping information recorded in the subscriber station, and then the corresponding L2 interface is identified by the forwarding table 132 of the peer PE 222. It is delivered to the destination L2 subscriber through the connection line (354 ~ 356).

In such a configuration, the LDP session between the PEs 320 to 322 and the CR-LSP connections 340 to 342 may be independent. The LDP session between the PEs 320 to 326 may be normal, but the CR-LSPs 340 to 342 may be independent. In case of a connection failure, packet loss may be prevented by storing existing mapping information, for example, mapping information using an LSP, in the forwarding table 132.

As described above, the L2VPN subscriber-specific QoS support method using the CR-LSP according to the present invention generates a CR-LSP for packet transmission between PEs, the subscriber's virtual connection line (PW), subscriber L2 interface and CR By mapping the -LSP connection information, it is possible to provide a separate CR-LSP for each subscriber, thus ensuring the QoS for each subscriber.

Claims (2)

Generating a subscriber-specific CR-LSP by designating connection characteristics such as path, bandwidth, priority, etc. according to a desired QoS for packet transmission between subscribers in a MPLS L2VPN network; And a mapping step of mapping a subscriber L2 interface, PW information in an MPLS network, and connection information of the generated CR-LSP. The method of claim 1, The mapping step includes storing the subscriber L2 interface, the PW information, and the CR-LSP connection information in a forwarding table of a forwarding processor.

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