KR100684143B1 - Method and apparatus for providing various L2VPN service using Simplified multi protocol Label Switching mechanism - Google Patents

Abstract

The present invention relates to a method for performing various Layer 2 Virtual Private Network (L2VPN) services in an MPLS network by using a Simplified Multi Protocol Label Switching (SMPLS) scheme, and more specifically, an MPLS network. A method and apparatus for efficiently performing L2VPN service to minimize the load on each node in the network. According to one aspect of the present invention, a method for delivering voice data of an external network through a QSS network composed of a plurality of QSS (QoS Switching System) nodes is provided. The method includes receiving matching information from a soft switch outside the QSS network, retrieving subscriber information of the soft switch network, and providing each subscriber with the soft switch network subscriber to identify the soft switch network subscriber. Defining a VLAN ID for a VLAN and a label switched path between the ingress node and an egress node when voice data is received through an ingress node of the QSS network. And setting up a virtual circuit in the LSP, so that the voice data traffic is transmitted through the set virtual line.

Simplified MultiProtocol Label Switching (SMPLS), L2VPN Service

Description

Method and apparatus for providing various L2VPN services using Simplified multi protocol Label Switching mechanism}

1 is a diagram illustrating an MPLS-based network structure in which various L2VPN services are provided using a simplified MPLS (SMPLS) mechanism according to the present invention.

2 illustrates a flow of path information transmitted to each node for establishing an L2VPN virtual line in an MPLS network using the SMPLS mechanism according to the present invention.

3 is a flowchart illustrating a voice data information processing procedure of an external network according to an embodiment of the present invention.

4 is a flowchart illustrating a process of performing an L2VPN virtual line connection between VPN sites according to an embodiment of the present invention.

5 is a flowchart illustrating a processing procedure for providing a voice service through time division multiplexing (TDM) according to an embodiment of the present invention.

The present invention relates to a method for performing various Layer 2 Virtual Private Network (L2VPN) services in an MPLS network by using a Simplified Multi Protocol Label Switching (SMPLS) scheme, and more specifically, an MPLS network. The present invention relates to a method for efficiently performing L2VPN service to minimize load on each node.

Recently, service providers have focused on how to provide various services such as Frame Relay, Asynchronous Transfer Mode (ATM) circuits, and SONET / SDH through a common packet switched network. have. 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 converged communication, 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 be able to accommodate quality of service (QoS) required for each. As such, L2VPN (Layer 2 Virtual Private Network) service is essential for accommodating various existing services and various Ethernet services through the backbone network, and MPLS (MultiProtocol Label Switching) network is currently referred to as the most representative network for this purpose. The MPLS network for L2VPN service is a communication network that can differentiate the quality of service level, and is an aggregated control rather than a control band for subscribers between edges and edges in the network. The amount of load can be kept to a minimum and efficient control must be carried out.

In order to provide L2VPN services in MPLS networks, IETF pwe3 (Pseudo Wire Emulation Edge to Edge) is currently being discussed, and packet encoding method in network processor (NP) and label distribution protocol (LDP) Pseudo wire Setup and Maintenance using LDP: draft ietf pwe3 control to set up and maintain pseudo wires (or virtual circuits, hereinafter referred to as "virtual lines") in the Distribution Protocol. protocol 11.txt, October 2004, Expiration Date: April 2005).

The L2VPN service in the backbone network based on MPLS performs control processing according to the access service port. First, L2VPN processing according to VLAN identifier information, second, L2VPN processing according to connection information between private networks, and third, frame relay (Frame) as described above to provide multimedia service through soft switch. L2VPN processing is performed to accommodate existing services through Layer 2 information such as Relay, ATM (Asynchronous Transfer Mode) circuits, and SONET / SDH.

In order to provide such L2VPN processing, a function of setting VPN related information by the operator and delivering the set information to the peer using extended LDP and forwarding information for lookup using the VPN related information received from the peer through LDP You need the ability to create and pass it to the data plan. VPN-related information input by the operator for L2VPN configuration may include interface information, virtual circuit (VC) information, that is, virtual circuit identification (ID), virtual circuit group information, that is, group identification (Group Identification). ), And peer information of a label distribution protocol (LDP), that is, a peer address. Such information indicates group information and interface information for the L2VPN service, and a peer to which such information is delivered. The access traffic flowing from the subscriber to the inlet node is determined by the operator or frame information, and the virtual line identifier is determined. The group identifier uses port information. IETF pwe3 WG additionally defines PWid (Pseudo Wire identification (PWid)) Forwarding Equivalence Class (FEC) element as LDP extension for virtual line setup. That is, information is transmitted to the peer using a virtual line identifier (PWid) determined by the operator, and peer determination is also defined by the operator's input. This means that the operator must be aware of the peer.

For L2VPN configuration, if L2VPN related information is input for an interface input by an operator, a virtual line label value corresponding to the interface should be assigned. The forwarding information is created using the assigned virtual line label value. This forwarding information determines the subscriber side port to be output and changes the data to an appropriate L2 type in order to deliver data input from the MPLS network to the subscriber side. In order to generate such information, the VC label value allocated for each interface is used, and the generated forwarding information is transferred to a data plan.

VPN-related information entered by the operator is delivered to the peer using the extended LDP. Root information for the peer is based on information by a routing protocol such as Open Shortest Path First (OSPF). LDP has additionally defined VC Forwarding Equivalence Class (VC FEC) to deliver L2 VPN related information. The information transmitted includes a virtual line identifier (VC ID), a group identifier (Group ID), a VC label, and various parameter values for the interface. If peer peer also performs L2 VPN information setting and forwarding function and LSP is set in both directions, data can be transmitted / received between two peers.

In order to process L2VPN service as described above, signals such as LDP and routing protocols such as OSPF are processed for connection between edge and edge at each node in MPLS network. As described above, in order to perform L2VPN in the MPLS network, not only loads each edge node of the MPLS network but also increase complexity in the network due to protocol processing.

Accordingly, the present invention is designed to solve this problem, and the present invention is to reduce the load and complexity for processing the L2VPN by using a more simplified MPLS mechanism to perform L2VPN in the MPLS network. do.

According to one aspect of the present invention, a method for delivering voice data of an external network through a QSS network composed of a plurality of QSS (QoS Switching System) nodes is provided. The method includes receiving matching information from a soft switch outside the QSS network, retrieving subscriber information of the soft switch network, and providing each subscriber with the soft switch network subscriber to identify the soft switch network subscriber. Defining a VLAN ID for a VLAN and a label switched path between the ingress node and an egress node when voice data is received through an ingress node of the QSS network. And setting up a virtual circuit in the LSP, so that the voice data traffic is transmitted through the set virtual line.

According to another feature of the present invention, a network control processor for delivering voice data of an external network in a QSS network is provided. The network control processor includes means for receiving matching information from a soft switch outside the QSS network, means for retrieving subscriber information of the soft switch network, and identifying a subscriber of the soft switch network in the QSS network. Means for defining a virtual LAN identifier (VLAN ID) for each subscriber, and label switching between the ingress node and the egress node when voice data is received through an ingress node of the QSS network. Means for establishing a label switched path (LSP) and means for establishing a virtual circuit in the LSP, so that traffic framed with the voice data is transmitted through the established virtual circuit. do.

Hereinafter, with reference to the embodiments shown in the accompanying drawings, the present invention will be described in detail by way of example. However, the following detailed description is provided for illustrative purposes only and should not be construed as limiting the inventive concept to any particular physical configuration.

1 is a diagram illustrating an MPLS network structure in which various L2VPN services are provided using a simplified MPLS (SMPLS) mechanism according to the present invention. As shown, the MPLS network includes a plurality of network control processors (NCP) 110 and a QSS switching system (QSS) that perform label switching path (LSP) setup for L2VPN connection through a virtual line. Nodes 130, 140, and 150, and an ingress node 130 of the plurality of nodes is connected to CE (Customer Edge, 120) of VPN site 1 as an edge node (Provider Edge: PE), and an egress (Egress). QSS PE 150, which is a node), is shown as being connected to CE 160 at VPN site 2. The interface between the NCP 110 and each node 130, 140, 150 in the network is performed by well-known SNMP. In general, each node (130, 140, 150), a network processor for processing input packets, a local processor, an EOS (Ethernet over SONET) for processing Ethernet (Ethernet) information on the SONET and a TDM engine for TDM processing, etc. Include. Since such a configuration is known and not specific to the present invention, a detailed description of each element will be omitted.

For the L2VPN virtual line connection in the MPLS network structure, instead of performing the existing LDP target hello protocol, the NCP 110 uses a Label Switched Path (LSP) in the present invention. Perform setup. As shown, when the ingress node (QSS PE) 130 and the egress node 150 wish to create an LSP (tunnel) for the virtual circuit of the L2VPN, the NCP 110, Route information suitable for each node 130, intermediate node 140 and exit node 150 is transmitted. The entry node 130 includes a tunnel label, an operation code "push" (meaning to add a label to a packet), and Qos information (e.g., Qos type and bandwidth required). Will be sent. The intermediate node 140 transmits a tunnel label, an operation code "swap" (change of the tunnel label in the packet) and Qos information, and in the case of the exit node 150, the operation code (Operation code) "Pop" (delete label in packet) will be sent along with the tunnel label and Qos information.

In this regard, referring to FIG. 2, when a tunnel for an L2VPN virtual line is to be created between an entrance node QSS1 and an exit node QSS4, an entrance node QSS1, an exit node QSS4, and an intermediate node QSS2 are described. The flow of route information transmitted to each is indicated by arrows 3, 4 and 5, respectively.

As such, by simply passing the process of performing another protocol (e.g., RSVP: Resource Reservation Protocol) for tunnel creation and label information and QoS information transfer that had to be performed in the existing LDP target hello protocol, the NCP protocol is simply transmitted to each node. Can reduce the load and complexity.

After the LSP is created, the LSP uses the LDP Mapping Message to exchange L2VPN virtual line information between peer nodes, and each edge node transfers the virtual line information to the LSP information. Together, it was managed by the finite state machine (FSM). However, in the present invention, the NCP 110 will deliver L2VPN information, which is a virtual line, to the inlet node and the outlet node. As shown in FIG. 2, according to the characteristics of the input traffic flowing from the client to the inlet node, the inlet node needs to generate virtual line configuration information. The NCP 110 transmits this information to the inlet node. The virtual line configuration information includes, for example, VLAN identifier information in case of L2VPN between Ethernets, VLAN label identifier information for selecting an output port when a packet arrives at an exit node, and quality assurance (QoS) to be applied to such virtual line. ) Include information. Similarly, the NCP 110 transmits output port information on which client to output the traffic in the network to the exit node. As described above, in performing L2VPN, the NCP 110 transmits information required by each node to each node in the network.

L2VPN service provided by MPLS network can accommodate various input data traffic. 3 is a flowchart illustrating a voice data information processing procedure of an external network according to an embodiment of the present invention. The NCP receives the matching information from the soft switch to have an interface with the soft switch outside the MPLS network (301). In order to identify the soft switch network subscriber using the VLAN ID in the MPLS network, the soft switch network subscriber information is retrieved (302), and the VLAN ID for each subscriber is statically defined in advance (303). . When voice data flows from the client through two edge nodes of the MPLS network (304), the NCP establishes an LSP in the MPLS network (305), establishes a virtual line in the LSP (306), and delivers voice through the established virtual circuit. The framed traffic may be delivered (307).

4 is a flowchart illustrating a procedure for performing an L2VPN connection between VPN sites according to an embodiment of the present invention. As a general example, there is an example of connecting between VPN sites using VLAN ID information in an Ethernet frame. In order to flow traffic between VPN sites, a tunnel (LSP) must be established to connect network edges first, and then inside the tunnel, a virtual circuit, L2VPN, must be set up to determine which CE should actually flow data. To this end, the NCP performs LSP establishment between related CEs. In order to configure the LSP, topology information is collected by performing a link management protocol (LMP) at each node in the network (401). The LSP path for connecting the edge nodes at both ends is extracted based on the collected topology information (402). The LSP configuration information is transmitted to each node included in the LSP (403). Through the LSP configuration in the network, the NCP recognizes node addresses of edge nodes between both ends for configuring L2VPN (404). The virtual circuit setting information is generated in the LSP (tunnel) (405). Thereafter, the NCP determines which CE port it will actually flow through (406).

Each node receives the LSP configuration information from the NCP (407), and provides the LSP configuration information as forwarding information appropriate for each line card through which the traffic flows (408). From the NCP, the virtual line setting information including the interface information, the virtual line ID, the virtual line group ID, and the peer address is received (409). The received virtual line configuration information is managed in the node (410). The virtual line and the group ID for the access traffic flowing from the subscriber to the entry node are determined (411). In one embodiment, the virtual line ID is determined by operator or frame information and the group ID is determined by port information. The NCP maintains consistent information at both ends so that information at both ends is simultaneously managed when setting L2VPN (412). L2VPN information is required at both ends, and originally, the L2VPN information should be delivered to each peer through a tunnel LSP. However, in the present invention, since the simplified MPLS mechanism is used, the L2VPN information of the peer is also transmitted to the peer peer node by the NCP. This L2VPN information also provides appropriate forwarding information for each line card.

5 is a flowchart illustrating a processing procedure for providing a voice service through time division multiplexing (TDM) according to an embodiment of the present invention. L2VPN processing for accommodating existing services through Layer 2 information such as Frame Relay, Asynchronous Transfer Mode (ATM) circuit, SONET / SDH, and provides voice services through Time Division Multiplexing (TDM) from VPN1 to VPN2. If so, the NCP should establish an intranet tunnel LSP (501). In setting up the virtual line, LSP configuration information including the address of the peer is transmitted to each node by the NCP (502), and each edge node (PE) performs the virtual line setup based on this information (503). ). In the input PE of the MPLS network, the operator analyzes the input traffic and inputs the virtual line ID and the peer address according to the analysis result to set up the virtual circuit. In fact, when traffic is input, the network processor of the inlet node analyzes the TDM information inputted from the subscriber to the inlet node. The network processor at the ingress node examines the VLAN tag to recognize that the value of the data fill is TDM (504) and analyzes the signal channel of this data. In one embodiment, a destination number for connection establishment is accommodated in a predefined association control channel in an Ethernet frame by a Channel Associate (CAS) signaling technique. The signal channel information retrieval can reduce the load at the inlet node by analyzing only the channel of a fixed specific position, instead of retrieving all the information of the layer 2. That is, it is confirmed that channel information regarding each time slot in an actual TDM frame is listed as a TDM information configuration for voice information (505). This information is accumulated by header information representing the TDM information and stored 506 as intraframe data by the VLAN frame. The L2VPN traffic is transmitted through the virtual circuit to be connected to the peer based on the peer information received from the NCP (507).

In the foregoing description, the invention has been described in connection with specific embodiments, but modifications, ie, forms and detailed modifications, which fall within the spirit and scope of the appended claims are possible without departing from the spirit and scope of the invention. Will be self-evident. Accordingly, all such modifications will fall within the scope of the present invention.

The present invention is to provide a variety of L2VPN services, (1) L2VPN processing according to VLAN identifier information for providing a multimedia service through a soft switch, (2) L2VPN processing according to connection information between private networks, And (3) implement simplified MPLS mechanisms such as L2VPN processing to accommodate existing services through Layer 2 information such as Frame Relay, Asynchronous Transfer Mode (ATM) circuits, and SONET / SDH. By using the simplified MPLS mechanism according to the present invention, there is an effect of minimizing the load of each node in the MPLS network due to various L2VPN connection control and performing efficient connection control.

Claims (7)

In the method for delivering the voice data of the external network through a QSS network consisting of a plurality of QSS (QoS Switching System) nodes, the method, Receiving matching information from the soft switch of the external network; Retrieving subscriber information of the external network from the soft switch; Defining a virtual LAN identifier (VLAN ID) for each subscriber to identify the external network subscriber in the QSS network; Label Switched Path between the ingress node and the egress node based on topology information collected from each node of the QSS network when voice data is received through the ingress node of the QSS network. LSP), Transmitting LSP information corresponding to each of the inlet node, at least one intermediate node, and the outlet node included in the set LSP, and Establishing a virtual circuit in the LSP; And transmitting the voice data traffic through the set virtual line. delete According to claim 1, Tunnel Label (Tunnel Label), "Push" (Operation code) and the Qos information is transmitted to the inlet node, Tunnel Label, "Operation code" which is a tunnel code, "Swap" and Qos information is transmitted, and the exit node, the tunnel label, the operation code "Pop" is transmitted voice data transmission method of the external network. delete A network control processor for transmitting voice data of an external network in a QSS network, Means for receiving matching information from a soft switch of the external network; Means for retrieving subscriber information of the external network from the soft switch; Means for defining a virtual LAN identifier (VLAN ID) for each subscriber so as to identify subscribers of the external network; Label Switched Path between the ingress node and the egress node based on topology information collected from each node of the QSS network when voice data is received through the ingress node of the QSS network. Means for setting LSP), Means for transmitting LSP information corresponding to each of the inlet node, at least one intermediate node, and the outlet node included in the set LSP; Means for establishing a virtual circuit in the LSP; And the traffic framed by the voice data is transmitted through the set virtual line. In the method for performing the connection between the first private network (VPN) and the second private network in the MPLS network, Extracting an LSP path between the edge nodes based on topology information collected from each node of the MPLS network to connect the edge nodes of the first private network and the edge nodes of the second private network; Transmitting LSP configuration information to each node included in the LSP path; Recognizing the addresses of both edge nodes for establishing the virtual line through the LSP setting; Establishing a virtual circuit in the set LSP path; Determining a CE port to which the virtual line is connected; Method of performing connection between private networks comprising a. A method for providing a voice service through a time division multiplexing (TDM) from a first private network to a second private network in an MPLS network, the method comprising: The inlet node and the based on the topology information collected from each node of the MPLS network to connect between an inlet node receiving TDM traffic from the first private network and an outlet node outputting the TDM traffic to the second private network. Extracting the LSP path between the outlet nodes; Transmitting LSP configuration information to each node included in the LSP path; Establishing a virtual circuit in the set LSP path; Analyzing the TDM traffic information input to the inlet node; Storing the analyzed TDM traffic as data in a VLAN frame; Transmitting the TDM traffic stored as data in the VLAN frame through the virtual circuit. Voice service providing method through the TDM from the first private network to the second private network comprising a.

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