KR20080002089A - Mpls l2 vpn connection management in mpls over atm network - Google Patents

Abstract

A method and a system for managing a connection of an MPLS(Multi Protocol Label Switching) L2 VPN(Layer 2 Virtual Private Network) of an ATM(Asynchronous Transfer Mode) are provided to use a network security, a traffic engineering and a QoS(Quality of Service) of an MPLS network by using the MPLS network as VPN. A method for managing a connection of an MPLS L2 VPN of an ATM includes the steps of: generating a virtual LAN in a subscriber port of label terminal routers(320); activating a T-LDP(Label Distribution Protocol) cession between the label terminal routers(340); generating a virtual line between virtual LAN(Local Area Network), and exchanging a VC(Virtual Circuit) label corresponding to the virtual LAN through the T-LDP cession at the label terminal routers(370); and mapping the VC to a specific label switch path(380). The VC is generated by using the specific label switch path as a tunnel according to the T-LDP.

Description

Point-to-Point Two-Layer Virtual Private Network Connection Management Method and its Connection Management System in Multi-Protocol Label Switching Network Based on Asynchronous Transfer Mode {MPLS L2 VPN connection management in MPLS over ATM network}

1 is a configuration diagram showing the configuration of a general MPLS network.

2 is a block diagram showing the configuration of a point-to-point two-layer virtual line connection management system of the present invention.

Figure 3 is a flow chart for explaining the L2 VPN connection process according to the present invention.

4 illustrates CORBA IDL for T-LDP session establishment as an embodiment of the invention.

5 is a view showing CORBA IDL for creating a virtual line as an embodiment of the present invention.

6 is a diagram illustrating a double-labeled structure of a packet in an L2 VPN according to the present invention.

7 is a flowchart illustrating a process of deleting an L2 VPN connection created by FIG. 6.

* Explanation of symbols for the main parts of the drawings

100: network management system 110: host system interworking module

120: subscription module 130: equipment module

140: connection module 150: current module

160: performance / failure module 170: routing module

180: information storage unit 210, 220: LER

300: LSR

The present invention relates to a Multi Protocol Label Switching (MPLS) network based on Asynchronous Transfer Mode (ATM), and more particularly, to label termination in an MPLS network based on ATM high speed communication network. The present invention relates to a method and system for providing a point-to-point two-layer virtual private network (L2 VPN) service by connecting a virtual circuit (router circuit or pseudo wire) between routers.

Recently, service providers are focusing on providing various services such as frame relay, ATM circuit, and SONET / SDH through a common packet switched network. In addition, to provide such various services, efforts are being made to integrate and evolve various existing networks into one network. We are defining a next-generation converged network that can securely and securely provide broadband broadband services that combine convergence of telecommunications, broadcasting, and the Internet anytime, anywhere, and will evolve into a unified broadband convergence network (BCN). .

In particular, most networks except core networks are evolving into fast, economical and simple Ethernet networks. In order to accommodate these various services and networks in core network, it is necessary to accommodate quality of service (QoS) required. As such, L2 VPN service is essential for accommodating various existing services and various Ethernet services through the backbone network, and the MPLS network is currently referred to as the most representative network for this.

MPLS is a standardization underway in the MPLS Working Group (WTF) of the Internet Engineering Task Force (IETF), a proven standard for speeding up network traffic and making it easier to manage.

1 is a block diagram showing the configuration of a general MPLS network.

The MPLS switch in the high-speed network is a switch that performs not only the existing ATM function but also the MPLS function of the ATM method, and serves as a label edge router (LER) and a backbone exchange that serve as end-end exchangers for subscribers. It is divided into a label switch router (LSR). The dual LER creates a Logical IP Subnet (LIS) interface on the subscriber port to provide connectivity to the subscriber, analyzes the header of packets coming in through this LIS interface, and forwards the Label Switching Path (LSP) to which this packet is forwarded. After determining the Label Switching Path, the label corresponding to the LSP is encapsulated and transmitted to the output interface. In this case, the LSP is automatically generated by the Label Distribution Protocol (LDP) in conjunction with the IP routing protocol, but may be forcibly set to satisfy a specific condition. The LSP configured to satisfy a specific condition is called a constrained label switching path (CR-LSP). In addition, an LDP session (LC-ATM: Label Controlled-ATM) may be connected to the LSR to transmit and receive a Label Distribution Protocol (LDP) message.

When the LSR receives a labeled packet, it checks only the label of the packet using LDP, changes the label, and delivers it to the specified output interface.

There are two types of L2 VPNs based on MPLS, which are point-to-point (Martini) and point-to-multipoint (VPLS) methods. Martini's MPLS L2 VPN is a point-to-point based L2 virtual line service that operates on an IP backbone through an IP / MPLS tunnel between L2 switches. The methods for providing this MPLS L2 VPN service are currently being standardized through the IETF's Martini draft and are already implemented and commercialized by many vendors.

In the case of MPLS L2 VPN, users can control the routing and multiplex with different L3 protocols without service provider involvement so that traffic between customers is not mixed, so users can use high quality virtual private network and network management for network operators. There is an advantage that makes it easy.

However, to provide the MPLS L2 VPN, a function to control the creation / deletion / modification of a virtual line for the MPLS L2 VPN is required, but only the conventional high speed communication system does not provide such a function.

Accordingly, an object of the present invention is to connect a virtual line between specific label end routers to connect a point-to-point two-layer virtual private network (MPLS L2 VPN) between Ethernet subscribers in the MPLS network and to manage the network security and traffic in the MPLS network. To provide subscribers with engineering and quality of service (QoS).

Point-to-point two-layer virtual private network connection management method in the ATM-based MPLS network of the present invention for achieving the above object comprises the steps of: creating a virtual LAN in the subscriber port of the label-end router; Activating a T-LDP session between the label terminated routers; Creating a virtual line between the virtual LANs, and the label terminating routers exchanging a VC label corresponding to the virtual LAN through the T-LDP session; And a fourth step of mapping the virtual line to a label switching path.

In an ATM-based MPLS network, a point-to-point two-layer virtual private network connection management system controls the T-LDP session activation and virtual line connection between specific label end routers that have a label switching path established according to a request from an operator, thereby controlling between the label end routers. A network management system for managing a two-layer virtual private network; And creating a virtual LAN at the subscriber port according to the instruction from the network management system, creating the virtual line between the virtual LANs, activating the T-LDP session, and exchanging VC labels corresponding to the virtual LANs. And label termination routers that map a virtual line to the specific label switching path.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

2 is a block diagram showing the configuration of the point-to-point two-layer virtual line connection management system of the present invention.

The point-to-point two-layer virtual line connection management system of FIG. 2 includes a network management system 100, LERs 210 and 220, and an LSR 300.

The network management system 100 manages the point-to-point two-layer virtual private network in the MPLS network by controlling the T-LDP session activation and the virtual line connection between the specific LERs 210 and 220 for which the CR-LSP is set according to an operator's request. .

To this end, the network management system 100 includes information on each port of the switched routers constituting the MPLS network, virtual LAN (VLAN) generation information generated on the port, and CR-LSP connection information between specific label end routers (LER). Stores L2 VPN-related information such as T-LDP (Target-LDP) session activation information, virtual line connection information, and the corresponding LER (210, 220) when receiving a virtual line generation request between specific LERs (210, 220). Instructs the creation of a VLAN to control the connection of the virtual line by checking whether the target-LDP (T-LDP) session between the LER (210, 220) is activated, and whether the virtual line exists between the VLANs of the LER (210, 220). .

The network management system 100 is a higher system interworking module 110, subscription work module 120, facility module 130, connection module 140, the current module 150, performance / failure module 160, The routing module 170 and the information storage unit 180 are provided.

The upper system interworking module 110 interoperates with a higher system on a different platform from the network management system 100, namely, a subscription generation system, a failure management system, a facility management system, and the like, and commands the network system 100 to the network management system 100. To pass. The upper system interworking module 100 transmits the subscriber's subscription information for the L2 VPN from the subscription generation system to the subscription operation module 120.

The subscription operation module 120 transmits the information on the port and connection to be used by the subscriber to use the L2 VPN according to the subscription information provided from the upper system interworking module 110 to the facility module 130 and the connection module 140, respectively. Transmits and notifies the upper system interworking module 110 of the result. That is, when a virtual line connection between the LERs 210 and 220 is requested from the subscriber, the subscription work module 120 uses the information stored in the facility information storage unit 180 to form an L2 VPN between the LERs 210 and 220. Information on the port to be used by the subscriber in the LER (210, 220) transmits to the facility module (130). In addition, the subscription module 120 transmits the information related to the CR-LSP connection already established between the LER (210, 220) by the operator to the connection module 140.

The facility module 130 may create / delete / modify VLANs for subscriber ports of the LERs 210 and 220 and T-LDP sessions between the LERs 210 and 220 based on the port information provided from the subscription work module 120. Control the enable / disable function. That is, the facility module 130 determines the subscriber ports to create a VLAN on the basis of the port information provided from the subscription operation module 120 when the L2 VPN is formed, then bundles the corresponding ports to create a VLAN. Delete the VLAN specified by the operator. The facility module 130 instructs the LER 210 and 220 to activate the T-LDP session when the T-LDP session is not activated between the LERs 210 and 220 to which the virtual line is to be formed. Instructs the LER 210, 220 to deactivate the T-LDP session.

The connection module 140 controls the generation / deletion / modification of the virtual line that tunnels the CR-LSP already established between the LERs 210 or 220 based on the connection information provided from the subscription work module 120.

The current module 150 reads the information (facility information and connection information) set in the routers (LER, LSR) of the MPLS network, reflects them to the facility information storage unit 181 and the connection information storage unit 181, and reflects them. Synchronization allows the final information to be maintained in the facility information storage unit 181 and the connection information storage unit 181.

The performance / failure module 160 verifies and tests the traffic and the failure status of the VLAN, the CR-LSP, the virtual line, and the routing module 170 performs the function of finding information about the virtual line or the CR-LSP connection.

The information storage unit 80 includes facility information (port, VLAN, T-LDP session activation information), connection information (virtual line, CR-LSP, virtual line and CR-LSP mapping information), performance information, and faults in the MPLS network. The information is stored and managed in the facility information storage unit 181, the connection information storage unit 182, the performance information storage unit 183, and the failure information storage unit 184, respectively.

The LER 210 or 220 creates a VLAN by binding the designated Ethernet ports according to the instruction from the network management system 100 and creates a VLAN through a preset CR-LSP tunnel between the LERs 210 and 220 according to the T-LDP. Is created between VLANs. The LER 210 or 220 generates a virtual circuit ID (VCID) for identifying a VLAN internally and then exchanges the VC label corresponding to the VCID through a T-LDP session, and then CR- Map to LSP. Accordingly, when a packet is received through a port belonging to a VLAN, the LER (210, 220) labels the packet with the VC label as an internal label, and then labels the packet with the CR-LSP label as an external label again. Output through

When the LSR 300 receives a labeled packet, the LSR 300 checks only the outer label of the packet and switches the corresponding packet. This switching function is the same as the conventional LSR.

3 is a flowchart illustrating an L2 VPN connection process according to the present invention.

First, assume that a CR-LSP has already been set up between an incoming LER 210 having an IP address 1.1.1.1 and an outgoing LER 220 having an IP address 2.2.2.2.

If the subscription information of the subscriber requesting the creation of the virtual line between the LER 210 and the LER 220 for the L2 VPN is received in the subscription management system (not shown), the subscription information is an upper system interworking module of the network management system 100. Via 110 is sent to the subscription module 120 (step 310).

The subscription work module 120 receiving the subscription information uses the information stored in the facility information storage unit 180 to use the LER 210 or 220 to use the L2 VPN according to the subscription information provided from the upper system interworking module 110. At) transmits the port information to be used by the subscriber to the facility module (130). In addition, the subscription module 120 transmits the information related to the CR-LSP connection already established between the LER (210, 220) by the operator to the connection module 140.

The facility module 12 instructs the LERs 210 and 220 to create VLANs on the corresponding ports. Accordingly, the LERs 210 and 220 bundle packets for use by the L2 VPN subscriber and broadcast packets between the ports. Create a VLAN that allows the user to send and receive (step 320). At this time, the target router (LER) IP address of the VLAN created in the LER 210 becomes 2.2.2.2, which is the IP address of the LER 220, and the target router (LER) IP address of the VLAN created in the LER 22 is The IP address of the LER 210 becomes 1.1.1.1.

Next, the facility module 120 searches the facility information storage unit 181 to check whether a T-LDP session capable of sending and receiving a VC label for forming an L2 VPN is active between the LERs 210 and 220. (Step 330).

At this time, if the T-LDP session is not activated between the LER (210, 220), the facility module 120 instructs the LER (210, 220) to activate the T-LDP session. Accordingly, the LERs 210 and 220 activate the T-LDP session by establishing Hello adjacency through the LDP Hello message (step 340). FIG. 4 is a diagram illustrating a common object request broker architecture (CORBA) IDL for establishing a T-LDP session as an embodiment of the present invention.

If the T-LDP session is already activated between the LERs 210 and 220 in step 330, the process proceeds directly to the next step (350).

Next, the connection module 130 searches the connection information storage unit 182 to check whether a virtual line exists between the VLAN of the LER 210 and the VLAN of the LER 220 generated in step 320 (step 350). If a line does not exist, a virtual line is generated to the LERs 210 and 220 to generate a virtual line between the two VLANs (step 360). At this time, the virtual line is generated by the CR-LSP between the LER (210, 220) as a tunnel by the T-LDP. FIG. 5 illustrates a CORBA IDL for generating a virtual line as an embodiment of the present invention.

Next, the LER 210, 220 generates a VCID for identifying the VLAN internally and then exchanges the VC label through the activated T-LDP session using the VCID (step 370).

For example, LER 210 generates VCID 50 for its VLAN and then notifies LER 220 to use VC label 500 for VCID 50 via a T-LDP session. In this regard, the LER 220 informs the LER 210 to use the VC label 501 for the VCID 50 via a T-LDP session.

When the VC label exchange is completed, the LERs 210 and 220 map the generated virtual line with the predetermined CR-LSP between the LERs 210 and 220 (step 380). The mapping information is transmitted to the connection module 140 and stored in the connection information storage unit 182.

When the L2 VPN is formed in this way, the LER 210 labels the VC label as the internal label for the Ethernet packet flowing through the port belonging to the VLAN, and then labels the CR-LSP label as the external label to the LER 220 side. send.

For example, if the CR-LSP label at the LER 210 is 600, the LER 210 first attaches the VC label 501 to the Ethernet packet coming through the port belonging to the VLAN, as shown in FIG. 6A, and then places the CR-LSP on it. After attaching the label 600, the packet is transmitted to the LER 220 through the CR-LSP.

Conversely, if the CR-LSP label at LER 220 is 601, LER 220 first attaches VC label 500 to the Ethernet packet coming through the port belonging to the VLAN, as shown in FIG. After attaching the LSP label 601, the packet is transmitted to the LER 210 through the CR-LSP.

In this case, when the LSR 300 receives a labeled packet, the LSR 300 checks the external label and switches the packet.

The current module 150 reads the information (equipment information and connection information) of the LER (210, 220) and LSR (300) on a regular basis and the information of the facility information storage unit 181 and the connection information storage unit 181 In comparison with the above, even if the information of the LERs 210 and 220 and the LSR 300 is changed during the L2 VPN service, the changes can be directly reflected in the facility information storage unit 181 and the connection information storage unit 181.

7 is a flowchart illustrating a process of deleting an L2 VPN connection created by FIG. 6.

If the delete command for the virtual line between the LER (210, 220) is authorized from the operator (step 710), the connection module 140 uses the connection information of the connection information storage unit 182, the corresponding virtual line is a specific CR-LSP Check if it is mapped to (step 720).

If the virtual line is mapped to a specific CR-LSP, the connection module 140 first issues an unmapping command to the LERs 210 and 220 to release the mapping to the CR-LSP (step 730).

When the mapping is released, the connection module 140 instructs the LER 210 or 220 to delete the virtual line and deletes the virtual line and stores the information in the connection information storage unit 182 (step 740). .

If the virtual line is not mapped with a specific CR-LSP in step 730, the virtual line is deleted by directly instructing the LER 210 or 220 to delete the virtual line.

The LER 210, 220 deactivates the T-LDP session when the virtual line is deleted and deletes the VLAN created in the port (steps 750, 760).

As described above, the present invention provides a virtual line for LER point-to-point L2 VPN service in an ATM-based MPLS network and enables connection management thereof so that subscribers can use the MPLS network as a virtual leased line. It can provide subscribers with network security, traffic engineering and quality of service (QoS) for MPLS networks.

Claims (9)

 A method for connecting a point-to-point two-layer virtual private network between label-terminated routers with a specific label switching path, Generating a virtual LAN at a subscriber port of the label-terminated router; Activating a T-LDP session between the label terminated routers; Creating a virtual line between the virtual LANs, and the label terminating routers exchanging a VC label corresponding to the virtual LAN through the T-LDP session; And And a fourth step of mapping the virtual line to the specific label switching path. The method of claim 1, wherein the virtual line is A point-to-point two-layer virtual private network connection management method in an ATM-based MPLS network, wherein the specific label switching path is generated as a tunnel according to T-LDP. The method of claim 2, wherein the third step A point-to-point two-layer virtual private network in an ATM-based MPLS network, after generating a virtual line ID corresponding to the virtual LAN and exchanging the VC label using the virtual line ID through the T-LDP session. How to manage connections. The method of claim 2, wherein the label switching path is Point-to-point two-layer virtual private network connection management method in an ATM-based MPLS network, characterized in that it is a limited label switching path (CR-LSP) forcibly set to satisfy certain conditions according to the operator's request. A network management system for managing a two-layer virtual private network between the label-terminated routers by controlling a T-LDP session activation and a virtual line connection between specific label-terminated routers in which a label switching path is established according to a request from an operator; And Create a virtual LAN at a subscriber port according to the instruction from the network management system, create the virtual line between the virtual LANs, activate the T-LDP session, exchange VC labels corresponding to the virtual LANs, and then A point-to-point two-layer virtual private network connection management system in an ATM-based MPLS network having the label termination routers for mapping a circuit to the specific label switching path. The network management system of claim 5, wherein An information storage unit for storing facility information and connection information for the label terminal routers; A subscription operation module for extracting and outputting port information and connection information to be used for the virtual private network from the information storage unit according to the subscription information; A facility module that receives the port information from the subscription module and controls virtual LAN generation and T-LDP session activation for subscriber ports of the label end routers; And Point-to-point two-layer virtual private network connection management system in the ATM-based MPLS network characterized in that it comprises a connection module for receiving the connection information from the subscription operation module to control the connection of the virtual line. 8. The router of claim 7, wherein the label terminated router is A point-to-point two-layer virtual private network connection management system in an ATM-based MPLS network, wherein the virtual line is generated using the label switching path as a tunnel according to T-LDP. 8. The router of claim 7, wherein the label terminated router is Point-to-point layer 2 in ATM-based MPLS networks, wherein the virtual line ID corresponding to the virtual LAN is internally generated and the VC label is exchanged through the T-LDP session using the virtual line ID. Virtual Private Network Connection Management System. 6. The router of claim 5 wherein the label terminated router is Point-to-point in an ATM-based MPLS network, characterized in that the Ethernet packet flowing through the virtual LAN labeling the VC label as an internal label and labeling the label switching path label as an external label again. Two-layer virtual private network connection management system.

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