KR100668283B1 - Method and Apparatus for controlling connection between edges in a transport network based on Minimized Generalized Multi Protocol Label Switching mechanism - Google Patents

Abstract

The present invention relates to a minimum Generalized Multi Protocol Label Switching (GMPLS) mechanism for reducing the load associated with connection control between nodes in a transport network layer and performing efficient connection. According to an aspect of the present invention, a method for controlling inter-node connections in a transmission network including a plurality of nodes and a Network Control Processor (NCP) is provided based on a GMPLS mechanism. The method comprises the steps of: generating link interconnection information by performing a Link Management Protocol (LMP) at each node in the transmission network and transmitting the link correlation information to the NCP; and receiving from the respective node at the NCP. A second step of generating captophorol information based on the link correlation information; and setting a label switched path (LSP) based on the cloak topology information in the NCP and corresponding to each node in the network. A third step of transmitting connection information suitable for a location characteristic, and a fourth step of generating forwarding information based on the connection information received from the NCP at each node.

Generalized Multi Protocol Label Switching (GMPLS) mechanism, Link Management Protocol (LMP), Label Switched Path (LSP)

Description

Method and Apparatus for controlling connection between edges in a transport network based on Minimized Generalized Multi Protocol Label Switching mechanism in transport network

1 is a system diagram for realizing a minimum GMPLS mechanism for transmission network connection control according to an embodiment of the present invention.

2 is a flowchart of a procedure for performing connection control based on a minimal GMPLS mechanism according to an embodiment of the present invention.

3 is a flowchart illustrating a procedure of a link management protocol (LMP) performed at each node according to an embodiment of the present invention.

4 is a flowchart illustrating an operation in which an NCP 110 performs LSP setup in a network using network topology information according to an embodiment of the present invention.

5 is a flowchart illustrating an operation of configuring forwarding information to be used for a line card based on connection information transmitted to each node in a network by the NCP 110 according to an embodiment of the present invention.

The present invention relates to a mechanism for controlling the connection between the edge nodes in the transport network layer, specifically, to reduce the load associated with the connection control between the edges in the transport network layer and to minimize the generalized Multi Protocol Label Switching (GMPLS) ) Mechanism.

Recently, due to the saturation of wired / wireless voice services and new markets such as wired / wireless, broadcasting and convergence services, new value added is needed. This will lay the foundation for the growth of the IT industry by securing a competitive edge through the discovery of new IT services and markets.In recent years, telecommunications operators have established existing Frame Relay and ATM (Asynchronous) services to provide various services such as voice, data, and video. Transfer Modes Efforts are being made to integrate various networks such as circuits, synchronous optical networks (SONET / SDH), and IP networks into one network.

In particular, the increase in Internet subscribers has led to a surge in data traffic and demand for high-quality Internet services (250 Gbps in 2000, 259 Tbps in 2005, 1000 Tbps in 2010), and 2 to 5 times the bandwidth increase per subscriber per year. As such, the Broadband Convergence Network (BCN) is defined as a next-generation converged network that can securely and securely use broadband broadband quality service converged with communication, broadcasting, and the Internet anytime, anywhere.

The Internet Engineering Task Force (IETF) Common Control And Measurement Plane (CCAMP) Working Group has been working on Generalized Multi Protocol Label Switching (GMPLS), which is applicable to these diverse networks. The connection control can be performed according to the characteristics of each network. In other words, GMPLS supports various switch capabilities (e.g., packet switch capability, lambda switch capability) for higher generalized control plans, whether IP networks, SDHs or optical cross networks. It includes the OXC switch capability (Optical Cross connect switch capable), and performs the Link Management Protocol (LMP) for extending and managing existing MPLS and routing functions.

However, to evolve into an integrated network, it is necessary to accommodate various services and interfaces at network nodes. In particular, the transport network (TN) layer must integrate and accommodate the characteristics of various subscriber networks such as wired, wireless, and broadcast, and must be linked with a service and control layer that provides development and use environment for various application services. . Among the main requirements of the transport network layer, the quality assurance network provides a communication network that can differentiate and provide quality of service (QoS) levels such as transmission speed, loss, and delay according to user and service level for end to end sections. Refer.

The services of various subscriber networks that need to be integrated at the transport network layer are as follows. First, it provides a dedicated line of VC 3 or VC 4 as a SONET / SDH leased line service. Second, as an Ethernet Leased Line Service, there is an Ethernet Private Line (EPL) service and an Ethernet Virtual Private Line (EVPL) service. The EPL service connects an Ethernet signal to a point-to-point (PTP) point for a specific single subscriber. It must be able to be allocated and the bandwidth should be dynamically allocated in VC 3 or VC 4 units. In addition, EVPL service should be able to establish L2VPN by sharing bandwidth of a specific line, and bandwidth should be dynamically allocated by VC 3 or VC 4 unit. Third, as a MPLS L2VPN (Multi-Protocol Label Switching Layer 2 Virtual Private Network) service, a path control function between VPN sites must be supported for a client that provides an Ethernet-based MPLS L2VPN service of PTP (Point to Point). Fourthly, as an Internet access service, an Internet service such as best effort is provided. Fifth, as a real time multimedia service, a premium service such as voice or video ensures a QoS guaranteed path.

In order to process the above services, the conventional transmission network processes the edge-to-edge connection in the network by using various signal and routing protocols. In other words, an explicit route was established using RSVP (Resource reServation Protocol) for SDH and Ethernet leased lines, and LDP martini (LDP) which extended Label Distribution Protocol (LDP) for L2VPN service was established. VC information of peer node is obtained and routing protocol and LDP are used for internet service. As such, the conventional transmission network uses various protocols for accommodating various services, and the load may significantly affect the high speed transmission network.

In the transport network layer, not only these various services and connections, but also the aggregated control between edges and edges in the network, the amount of load due to the control mechanism must be minimized and efficient control can be performed. That is, the edge-to-edge connection in the transmission network is performed by a network control processor (NCP) that manages the entire network, and a mechanism for minimizing the connection control load at the edge is required.

In accordance with the above-described needs, an object of the present invention is to provide a method for performing edge-to-edge connection control in a transport network layer.

It is still another object of the present invention to provide a method for performing edge-to-edge connection control of a transport network layer based on a minimum GMPLS mechanism capable of guaranteeing QoS and reducing load due to intra-network connection control.

In order to achieve the above object, according to an aspect of the present invention, there is provided a method for controlling inter-node connections in a transmission network comprising a plurality of nodes and a Network Control Processor (NCP). The method comprises the steps of: generating link interconnection information by performing a Link Management Protocol (LMP) at each node in the transmission network and transmitting the link correlation information to the NCP; and receiving from the respective node at the NCP. A second step of generating captophorol information based on the link correlation information; and setting a label switched path (LSP) based on the cloak topology information in the NCP and corresponding to each node in the network. A third step of transmitting connection information suitable for a location characteristic, and a fourth step of generating forwarding information based on the connection information received from the NCP at each node.

According to another aspect of the invention, there is provided a means for receiving link cross-correlation information from each node in a transmission network, and means for generating cloakforol paper information based on the link cross-correlation information received from each node. And means for establishing a label switching path (LSP) based on the mantle topology information and transmitting connection information suitable for the location characteristic to each node in the network.

According to the GMPLS mechanism proposed by the present invention, signaling for connection in the network is provisioned by the network control processor (NCP), and the route determination for connection path determination is performed by the link management protocol of GMPLS ( It relies on network topology information according to the result of performing Link Management Protocol (LMP). More specifically, the features of the GMPLS mechanism of the present invention are as follows.

First, path selection for a connection request in NCP is based on topology information, which is attribute information of a link including correlation information with neighbor nodes collected at each node.

Second, each node performs LMP to calculate link correlation information with neighbor nodes, and expands the contents of the link management information base (LMIB) to provide sufficient information about the link to the NCP. Include. LMP is one of the GMPLS protocols. The two main functions are control channel management and link property correlation. Control channel management establishes and maintains control channels between two adjacency nodes using Config messages and a quick keep alive mechanism. The link attribute correlation function is for aggregating multiple data links into one traffic engineering (TE) link and synchronizing the attributes of the TE link. As part of the link attribute correlation function, the exchange of LinkSummary messages is defined. The LinkSummary message contains local and remote link identifiers, a list of all data links contained in the TE link, and various link attributes. The LinkSummaryAck or LinkSummaryNack message represents the agreement and disagreement of link characteristics between neighbor nodes with respect to the LinkSummary message. For more information about LMP, see "Link Management Protocol (LMP)" (draft-ietf-ccamp-lmp-10.txt), released in October 2003 by J. Lang.

According to an embodiment of the present invention, by adding the following routing information extensions of GMPLS to the LMIB of the LMP, it is possible to replace the Routing Information Base (RIB) function of the routing block.

Link Local Identifier

Link Remote Identifier

Link Protection Type

Interface Switching Capability Descriptor

Shared Risk Link Group.

Third, all connections are provided by the NCP and use GMPLS generalized labels for data transmission to the network.

Hereinafter, with reference to the embodiments shown in the accompanying drawings 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 system configuration diagram for realizing a minimum (Minimized) GMPLS mechanism for transport network layer connection control according to an embodiment of the present invention. Such a system can accommodate any traffic such as TDM and the Internet, and must satisfy the reliability and quality required at the transport network layer. As shown, the system includes a Network Control Processor (NCP) 110 and a plurality of nodes 120a-120d connected to Ethernet or SONET / SDH. For convenience of description, it is illustrated that only four nodes are included in the drawings, but it will be understood that the present invention is not limited to this physical configuration. In addition, the connection between the NCP 110 and the nodes will be performed by the Simple Network Management Protocol (SNMP).

A network control processor (NCP) 110 provides signaling for intra-network connection for edge-to-edge connection control in a transmission network. A network topology is received by receiving link correlation information from a node as described below. It configures the information, establishes LSP (Label Switching Path) in the network, and delivers the appropriate connection information to each node in the network.

All connections in the network will consist of QoS-based connection establishment by NCP request. In addition, backup connections are required for protection of currently active connections, and NCP will establish backuppath connections before or after the active connection for these connections.

The nodes 120a and 120b are nodes connected to the Ethernet and include a packet interface unit (PIU) 122 for receiving Ethernet and Internet (IP) traffic. The PIU 122 includes a local processor on which an Ethernet / Internet matching unit and a queuing engine are mounted, memory for application blocks, and a network processor.

Nodes 120c and 120d are nodes connected to SONET / SDH and include an SDH Interface Unit (SIU) 124 for receiving TDM traffic. The SIU 124 includes a local processor on which a SONET matching unit and a queuing engine are mounted, memory for TSOT, TDM engine, Ethernet over SONET (EoS), network processor (NP), and application blocks.

The integrated cell switch 140 is a cell-based packet switch having a self routing function, and various protection switching operations vary according to the position of the network. The integrated cell switch 140 includes a switching table for self-routing of the switch, and generates a switching header using the switching table for all input data, and then transmits the generated switch header to the switch fabric. PIU 120 or SIU 130 may be connected to the switch fabric to any port.

2, a flow diagram of a procedure for performing connection control based on a minimal GMPLS mechanism in accordance with the present invention is shown. In step 210, each node 120a-120d performs a link management protocol (LMP) to generate link correlation information and send it to the NCP 110. In order to accommodate various services in the transport network and to establish connection settings for each service, a connection path must be determined. In order to determine the connection path, the NCP 110 needs to know link information of each node 120a-120d in the network. Such link information in the network is based on link information by LMP performed in each node. The link information according to the result of performing the LMP may be the basis of information that is flooded for topology information of the network when the routing protocol is performed. A detailed LMP execution procedure at each node will be described later with reference to FIG. 3.

In step 220, the NCP 110 configures overall network topology information based on link correlation information received from each node 120a-120d. The NCP 110 may perform a network topology information construction algorithm to configure network topology information including link information existing in each node and resource information included in the link. As a result of performing this algorithm, topology information is constructed in NCP to extract the path for connection establishment.

In step 230, the NCP 110 establishes a label switching path (LSP) based on the cloak topology information configured in step 220 and transmits connection information appropriate to the location characteristic to each node in the network.

In step 240, each node 120a-120d in the network generates forwarding information based on the connection information received from the NCP 110 and transmits it to the line card. In the application block of each service, forwarding information suitable for each line card should be configured using the connection information received from the NCP. A detailed procedure for generating forwarding information will be described in detail with reference to FIG. 5.

Specifically, according to the present invention, the functions required for each service for connection between edge nodes in a network are as follows.

For SONET / SDH Leased Line Service, the connection between Customer Edge (CE) and Provider Edge (PE) is performed through OIF UNI 1.0 and intra-node nodes by NCP. Data transmission to the network is performed by routing by a time slot.

The Ethernet Leased Line Service receives an Ethernet frame, and data transmission to the network is performed by time slots.

The Virtual Private Wire Service (VPWS) service is a two-level stacking consisting of a virtual circuit (VC) label for the identification of an egress ethernet port and a label for the intranet tunnel LSP. ) Is required.

IP packets input to provide Internet and Premium Service require a label of the tunnel LSP for network transmission.

Backup path connections are required to protect the currently working connections, and NCP establishes backup path connections before or after the working connections for these connections.

All connections are made based on QoS based on NCP requests.

3 shows a flowchart of an LMP procedure performed at each node according to an embodiment of the present invention. The LMP block of each node 120a-120d receives the shape information of its own node from the shape control block in order to know the link information in the node (S301). Before performing the link correlation function based on the received shape information, it is checked whether each link connected to its node is connected (S302). Link connection confirmation is a physical connection confirmation of a data link, and a test message is sent directly to a neighbor node on a data link through a link connection confirmation and interface identifier exchange between nodes.

The neighbor node adds its link information to the received test message and transmits the link connection result through the control channel (S303). When a test of such a link is applied to each link and the test is completed, the link information and the correlation information between the link of the related party and the related link are transmitted to the neighbor node using LinkSummary, LinkSummaryAck, LinkSummaryNack messages, etc. ). This correlation information is stored as local information of each node for configuration of topology information in the NCP 110 (S305). The link correlation information configured in the own node is transmitted to the NCP 110 based on the LMP Management Information Base (MIB) information (S306).

Now, referring to the operation in the NPC 110, NCP receives link correlation information from each node in the network (S307), based on the received link correlation information and the link information existing in each node and the link In order to configure the resource information, the topology information construction algorithm will be performed (S308). As a result of performing this algorithm, in NCP, topology information for selecting paths for connection establishment is configured (S309).

4 is a flowchart illustrating an operation in which an NCP 110 performs LSP setup in a network using network topology information according to an embodiment of the present invention. Intra-network LSP configuration is achieved by passing LSP connection information to each node according to the service type. When the LSP setting request arrives from the operator (or network operator) (S401), the NCP 110 performs in-network LSP setting (S402). In detail, for the in-network LSP setting, the service type for which the LSP setting is required is determined (S403). The LSP connection information is transmitted to each node in the network according to the location characteristics of each node in the network according to the determined service type. First, the LSP is configured in the network, and then the connection information suitable for the service is transmitted to the edge node including the ingress node and the egress node, thereby mapping the input / output traffic to the LSP in the network. Specifically, if the type of service requested is an SDH Leased Line (SLL), the ingress node forwards the incoming SDH traffic to the output port through time slot conversion without any modification. In operation S408, the type slot information 404 is transmitted to the inlet node. In case of Ethernet Leased Line (ELL), the Ethernet frame-type traffic input through the GbE port is transmitted to the output port through EOS processing, and thus the VLAN ID 405 is transmitted to the inlet node (S408). In each case of L2VPN and IP / Multimedia service, VLAN ID 406 and IP address 407 are forwarded to the entrance node by labeling the incoming Ethernet frame and IP packet type traffic to the output port. (S408).

In addition, for each intermediate node included in the set LSP, the appropriate connection information is transmitted according to the service type (S409). In the SDH LSP configuration, the output port is determined by changing a time slot (TS) at an intermediate node in the network, and the packet configuration is determined by label swapping at an intermediate node in the network. Therefore, in case of SDH dedicated line (SLL) and Ethernet dedicated line (ELL) service, time slot information (TS, 410, 411) is transmitted as connection information (S414), and in the case of L2VPN and IP service, VC (Virtual Circuit: Virtual) Line) and tunnel label (TL) information 412 and 413 are transmitted to intermediate nodes (S414).

5 is a flowchart illustrating an operation of configuring forwarding information to be used for each line card based on connection information transmitted to each node in the network by the NCP 110 according to an embodiment of the present invention. Each node receives connection information for each service type from the NCP 110 (S501). The service application block of each node determines a service type based on the received connection information (S502), configures forwarding information to be used for the line card according to the service type, and transmits it to the line card (S503-S506).

Specifically, when the service type is an SDH leased line or an Ethernet leased line service, the time slot information and the LSP index for the input and the output as the general label information and the information about the input / output port received from the NCP 110, (the subsequent protection / After the forwarding information including survivability information is generated for recovery transfer, the UE transmits the forwarding information to the SDH line card and the Eos (Ethernet over SDH) line card (S503 and S504).

In addition, in case of L2VPN and IP / multimedia service, information about input / output port received from NCP 110, VC (Virtual Circuit) label information, tunnel label (TL) information, LSP index, QoS information to be added to the packet After generating the forwarding information including a, and transmits to the GbE (Gigabit Ethernet) line card and the IP line card (S505, S506).

In the above, the present invention has been described in connection with specific embodiments, but the present invention is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes within the scope not departing from the technical spirit of the present invention. It will be apparent to one of ordinary skill in the art that this is possible.

According to the present invention described above, signaling for intra-network connection is provisioned by NCP and route determination for connection path determination is network connection control using minimal GMPLS mechanism performed by network topology information by LMP of GMPLS. Through the scheme, the network control processor simplifies the performance of the edge-to-edge connection in the transmission network, guarantees QoS for various services accommodated in the network, and reduces the load due to the connection control in the network.

Claims (12)

In the method for controlling the connection between nodes in a transmission network comprising a plurality of nodes and a Network Control Processor (NCP), A first step of generating link correlation information by transmitting a link management protocol (LMP) at each node in the transmission network to the NCP; Generating, by the NCP, cloak information based on the link correlation information received from each node; A third step of establishing a label switched path (LSP) based on the cloak topology information in the NCP and transmitting connection information suitable for a location characteristic to each node in the network; A fourth step of generating, at each node, forwarding information based on the connection information received from the NCP; Node-to-node connection control method in a transmission network comprising a. The method of claim 1, wherein the first step is Generating shape information by performing a shape control block at each node; Confirming whether the link is connected by transmitting a test message to the neighbor node through each link connected between the node and the neighbor node based on the generated shape information; Receiving a link connection result from the neighbor node through a control channel; Passing correlation information of its link information and its associated link to the neighboring node, wherein the correlation information is stored in local information of each node; Delivering the correlation information stored in its node to an NCP Node-to-node connection control method in a transmission network comprising a. The method of claim 1, wherein the third step, Determining a service type for which the LSP setting is required; Transmitting connection information suitable for each of the edge node of the LSP and at least one intermediate node included in the LSP according to the requested service type. A method for controlling connection between nodes in a transmission network comprising a. The method of claim 3, The service type is selected from the group consisting of SDH leased line services, Ethernet (Ethernet) leased line services, Layer 2 Virtual Private Network (L2VPN) services and IP / multimedia services. 5. The method of claim 4, wherein if the service type is determined to be an SDH dedicated line service, type slot information is transmitted to each of the edge node and the intermediate node. The method of claim 4, wherein if the service type is determined to be an Ethernet leased line service, VLAN identifier information is transmitted to the edge nodes, and type slot information is transmitted to each of the intermediate nodes. The method of claim 4, wherein if the service type is determined to be an L2VPN service, VLAN identifier information is transmitted to the edge node, and virtual circuit (VC) label information and tunnel label (TL) are transmitted to each of the intermediate nodes. A method for controlling connection between nodes in a transmission network that transmits information. The method of claim 4, wherein if the service type is determined to be an IP / multimedia service, an IP address is transmitted to the edge nodes, and tunnel label (TL) information is transmitted to each of the intermediate nodes. The method of claim 1, wherein the fourth step, Receiving the connection information from the NCP; Determining a service type based on the received connection information; Generating forwarding information suitable for the service type; Transmitting the generated forwarding information to a line card related to the service type. Node-to-node connection control method in a transmission network comprising a. The node of claim 9, wherein the forwarding information includes input / output port information, time slot information, LSP index, and survivability information when the service type is an SDH leased line or an Ethernet leased line service. To control connections between them. The node-to-node connection of claim 9, wherein the forwarding information includes input / output port information, VC / tunnel label information, LSP index, and QoS information when the service type is L2VPN or IP / multimedia service. Control method. Means for receiving link cross-correlation information from each node in a transmission network, wherein the link cross-correlation information is generated by each node performing a link management protocol (LMP); Means for generating cloak portal information based on the link correlation information received from each node; Means for establishing a label switching path (LSP) based on the mantle topology information and transmitting connection information appropriate to the location characteristic to each node in the network; Network control device comprising a.

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