CN102387070A

CN102387070A - Data protection method for T-MPLS (transport multi-protocol switching) shared protection ring before failure recovery

Info

Publication number: CN102387070A
Application number: CN2011103058157A
Authority: CN
Inventors: 董树荣; 周庆涛; 金鹏程; 吴梦军
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2011-10-11
Filing date: 2011-10-11
Publication date: 2012-03-21
Anticipated expiration: 2031-10-11
Also published as: CN102387070B

Abstract

The invention discloses a data protection method for a T-MPLS (transport multi-protocol switching) shared protection ring before failure recovery. The T-MPLS shared protection ring comprises initial nodes which are used for sending data, and destination nodes which are used for receiving the data, wherein nodes at two ends of a fault path are respectively a front node and a rear node, and before faults occur, the front node send the data to the rear node. The method is as follows: the data to be sent are divided into TMD (time division multiplex) data and non-TMD by the initial nodes, after the faults occur, the initial nodes are used for labeling data of a last frame, then caching the TMD data, and transporting the non-TMD data to the destination nodes along the opposite direction, and at the moment, the data sent by the initial nodes are subjected to wrapping protection which then is switched to steering protection after ending. The method combines and utilizes the advantages of the wrapping protection and the steering protection, the date sent by the initial nodes adopt the wrapping protection, and data of source nodes adopt a different treatment manner, so that the recovering speed of the faults can be improved, and the frame loss rate can be reduced.

Description

Data guard method before the fault recovery of T-MPLS protection rings

Technical field

The present invention relates to network communications technology field, the data guard method before the fault recovery of particularly a kind of T-MPLS protection rings.

Background technology

IPization along with telecommunication service; The business that transmits the network carrying is just from time division multiplexing (TDM;) be main to changing with main with IP; Be difficult to adapt to professional transmission demand towards TMD service transport network technology with SDH (SDH), the existing Ethernet technology can not well satisfy the transmission demand, and multiple label switching technology (MPLS) is also beyond one's ability.For professional transmission of carrier-class that adaptive surface connects, carrier-class Operations, Administration and Maintenance (OAM) and protection, this just needs connection-oriented Packet Transport Network technology, and this also will be following Packet Transport Network Developing Trend in Technology.

The emerge in multitude of the new business of transmission network and the expansion at full speed of network size, it is outstanding increasingly that the convergence of the communications industry shows, wherein; On the basis of legacy network; Development has higher speed, reliable more survivability, higher performance; The grouping conveying network of control and management capability is the main direction of development more flexibly, has merged the characteristics that circuit transmits network and grouping conveying network as the transmission multi-protocols exchanges (T-MLPS) of one of key technology of PTN of future generation.Have good development prospect, therefore, how to improve the focus that its reliability and management maintenance also become research, the problem of especially when there is fault in network, how recovering, and the packet loss etc. that how to reduce the data in the process of recovering.

T-MPLS is as the key technology of PTN, and T-MPLS is a kind of connection-oriented grouping tranmission techniques that on the art of MPLS, develops, and T-MPLS simplifies and transforms the MPLS technology; Increased the network model of transport layer; Protection is switched and OAM(Operation Administration Maintenance), and it has the general core technology characteristic of PTN technology, the transmission cost of promptly minimum every T-MPLS bit, based on the multi-service support of Packet Service; Confirmable service quality, powerful OAM administrative mechanism and webmaster ability etc.For the MPLS technology, T-MPLS has saved the unnecessary processing towards IP, and this brings effective reduction of cost to operator; Have service expansion capability completely, support the transmission of unlike signal.Also meet simultaneously the trend of network transformation,, have and to compare high survival ability with legacy network towards connection; The general purpose control plane can be adopted, interconnected and intercommunication can be guaranteed with present transmission network.

The looped network protection mode of T-MPLS mainly contains linear protection and switches and the protection rings dual mode.Protection rings (T-MPLS Shared Protection Ring; TM-SPRing) be the looped network that transmits through the T-MPLS LSP that the logical construction mode makes up; Adjacent node is two-way connection, can be the annexation of physics, also can be annexation in logic.One group of LSP that the transmission passage entity that is used for transport service between looped network node is based on T-MPLS realizes; The protection of TM-SPRing is to the adjacent node section, for the section that prevents adjacent node lost efficacy, under situation about breaking down; For realizing that data are protected fast; In TM-SPRing, following two protection mechanisms have been formulated, source routing (Steering) mode and loopback (Wrapping) mode.

The Wrapping protected mode is that the node detection on network arrives network failure, and fault side adjacent node sends switching request through the APS agreement to adjacent node.When certain node detection to losing efficacy or receiving switching request, the business that is forwarded to failure node will arrive another direction.

As shown in Figure 1 when the network operate as normal node A flow to the path of node D; Break down in path between network node C and the node D; The Wrapping protected mode is that data are walked around malfunctioning node, and as shown in Figure 2, at this moment service signal just returns from node C; Through Node B, node A, node G,, node F, node E, finally arrive node D.Through the method for loop-back path, make business datum pick up the path that bar is fit to.The method shortcoming of handling network failure through this Wrapping protected mode is that the path of route is not optimized path because the loopback malfunctioning node can make the path increase.

The Steering protection is meant sends switching request through all nodes on the APS agreement ring when network failure is arrived in network measuring.Each source node of the connection of point-to-point is carried out and is switched, and all T-MPLS connections that receive the network failure influence are switched to the protection direction from operative orientation, and after network failure or the disappearance of APS agreement, all affected business recoveries are to original path.As shown in Figure 3, when network measuring is broken down between node C and node D, no longer send to node D by the data of node A, but directly be switched on another paths through Node B and node C.The weak point of this reverse method is that packet loss is more.

Summary of the invention

The invention provides the data guard method before the fault recovery of a kind of T-MPLS protection rings, it is longer to solve traditional Wrapping protected mode path, Steering protected mode packet loss problem of higher.

Data guard method before the fault recovery of a kind of T-MPLS protection rings; Said T-MPLS protection rings comprises start node that sends data and the destination node that receives data; The node at failure path two ends is respectively front nodal point and posterior nodal point; Before fault took place, front nodal point transmitted data to posterior nodal point; Said data guard method comprises:

Start node is divided into two types of tdm data and non-tdm datas with the data of sending; After fault takes place; Start node carries out mark to the last frame data of sending; Then, non-tdm data is transferred to destination node (this mechanism can not influence the transmission of non-tdm data, has improved non-TDM business datum transmission efficiency) in opposite direction with the tdm data buffer memory; Front nodal point transfers to destination node with the mode of the The data loopback that receives, and in this process, when start node receives the Frame of its self marker, the tdm data of buffer memory and the data of new reception is transferred to destination node in opposite direction;

Said rightabout is and the opposite direction of data transfer direction between preceding start node and the destination node takes place fault.

Receive the data of its self marker at start node after, its data packets for transmission is drawn together the tdm data of buffer memory, new tdm data and the non-tdm data that receives.

Preferably, first frame data that start node sent before said front nodal point took place the fault that receives carry out mark, like this.

The present invention unites the advantage of having utilized loopback protected mode and source routing protected mode; With the issued The data loopback of start node protected mode; Reduce packet loss, in addition the The data source routing mode with new transmission of start node buffer memory has been protected, optimized transmission path.

Description of drawings

Node A is to the data flow sketch map of node D during Fig. 1 operate as normal;

Fig. 2 node C node D Wrapping protected mode sketch map that breaks down;

Steering protected mode sketch map when Fig. 3 node C node D breaks down;

Fig. 4 protects the claim frame structural representation.

Fig. 5 the present invention protects Steering protection switching flow figure by Wrapping.

Embodiment

T-MPLS protection rings as shown in Figure 1, it is made up of seven node A～G, can realize two-way communication between adjacent two nodes.The management maintenance module of communication system periodically detects the connection status of looped network, can detect with connectivity, form such as loopback detection.

If do not detect fault, explain that then network is in normal operating state, gets into next sense cycle; If detect fault; Situation such as opening circuit appears in loop are described, at this moment two end nodes of failure path begin to send out the protection request, APS information notice interdependent node; And communicate by letter with another malfunctioning node, accomplish switching of Loopback Mode.

As shown in Figure 2; This moment, the path of transfer of data was node A-Node B-node C-node D; Between detection node C and node D, break down, then node C and node D begin to send the protection claim frame, with auto switching information notice interdependent node; Node C carries out mark to what receive by A node first frame of issued data before fault simultaneously, and the method for mark is for to receive the reserved byte mark of Frame.

As shown in Figure 4; Frame generally comprises parts such as function type, tag head, reserved byte and data message; Latter two byte of the reserved byte of first frame data that node C receives after fault takes place is made as " 01 "; The data Loopback Mode after simultaneously fault being taken place transfers to node D, and its transmission path is node C-Node B-node A-node G-node F-node E-node D, can find out that these data can path node A.

The transmission of protection claim frame generally is that node transmits to next node; And its content territory comprises the ID of start node and the ID of destination node, and next node can compare with self ID after receiving the protection claim frame; If not start node or destination node; Then can the protection claim frame be transmitted down, after originating node is received this claim frame, stop to transmit to next node.

After start node is received the protection claim frame; This moment, start node was divided into two types with the data of sending; Wherein the tdm data buffer memory suspends and sends, but not tdm data continues to transfer in opposite direction node D; Simultaneously the last frame data of sending are carried out mark, labeling method is for being made as " 11 " last two of reserved byte.

As shown in Figure 3; When node A receives first frame data of node C mark; Begin to prepare the switch protecting mode, because show that the last frame data of its mark also will arrive, and receive the last frame data of its mark to node A this moment; Node A transfers to node D in opposite direction with the tdm data and the new data that receive of buffer memory, switches to the source routing protected mode.

Claims

1. the data guard method before the T-MPLS protection rings fault recovery; Said T-MPLS protection rings comprises start node that sends data and the destination node that receives data; The node at failure path two ends is respectively front nodal point and posterior nodal point; Before fault took place, front nodal point transmitted data to posterior nodal point; Said data guard method comprises:

Start node is divided into two types of tdm data and non-tdm datas with the data of sending, and after fault took place, start node carried out mark to the last frame data of sending, and then with the tdm data buffer memory, non-tdm data was transferred to destination node in opposite direction; Front nodal point transfers to destination node with the mode of the The data loopback that receives, and in this process, when start node receives the Frame of its self marker, the tdm data of buffer memory and the data of new reception is transferred to destination node in opposite direction.

2. data guard method according to claim 1 is characterized in that, first frame data that start node sent before said front nodal point took place the fault that receives carry out mark.