CN102387070B

CN102387070B - Data protection method for T-MPLS (transport multi-protocol switching) shared protection ring before failure recovery

Info

Publication number: CN102387070B
Application number: CN201110305815.7A
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: 2014-05-21
Anticipated expiration: 2031-10-11
Also published as: CN102387070A

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, particularly the data guard method before the fault recovery of a kind of T-MPLS protection rings.

Background technology

Along with the IPization of telecommunication service, transmit the business of the network carrying just from time division multiplexing (TDM,) be main to IP with main transformation, be difficult to adapt to the transmission demand of business towards TMD service transport network technology with SDH (Synchronous Digital Hierarchy) (SDH), existing ethernet technology can not well meet transmission demand, and multiple label switching technology (MPLS) is also beyond one's ability.For the carrier-class business transmission that adaptive surface connects, carrier-class Operations, Administration and Maintenance (OAM) and protection, this just needs connection-oriented Packet Transport Network technology, and this is also by the development trend that is following Packet Transport Network technology.

Transmit the emerging in multitude and the expansion at full speed of network size of new business of network, it is outstanding increasingly that the convergence of the communications industry shows, wherein, on the basis of legacy network, development has higher speed, survivability more reliably, higher performance, the grouping conveying network of control and management capability is the main direction of development more flexibly, has merged circuit and transmit the feature of network and grouping conveying network as the transmission multi-protocol exchange (T-MLPS) of one of key technology of PTN of future generation.Have good development prospect, therefore, the reliability and the management maintenance that how to improve it also become the focus of research, the problem of especially how recovering in the time that network exists fault, and how to reduce the packet loss etc. of the data in the process of recovering.

T-MPLS is as the key technology of PTN; T-MPLS is the connection-oriented grouping tranmission techniques of one developing in the art of MPLS; T-MPLS simplifies and transforms MPLS technology; increase the network model of transport layer; protection is switched and OAM(Operation Administration Maintenance), and it has the core technology feature that PTN technology is general, i.e. the transmission cost of minimum every T-MPLS bit, Supporting multi-services based on Packet Service; confirmable service quality, powerful OAM administrative mechanism and webmaster ability etc.For MPLS technology, T-MPLS has saved the unnecessary processing towards IP, and this brings effective reduction of cost to operator; There is service expansion capability completely, support the transmission of unlike signal.Also meet the trend of network transformation simultaneously, towards connection, have can be high compared with legacy network survival ability; General control plane can be adopted, the interconnected and intercommunication with present transmission network can be guaranteed.

The looped network protection mode of T-MPLS mainly contains linear protection and switches and two kinds of modes of protection rings.Protection rings (T-MPLS Shared Protection Ring; TM-SPRing) be the looped network that the T-MPLS LSP that builds by logical construction mode transmits; adjacent node is two-way connection, can be the annexation of physics, can be also annexation in logic.The Transfer pipe entity for transport service between looped network node is that one group of LSP based on T-MPLS realizes; the protection of TM-SPRing is for adjacent node section; for the section that prevents adjacent node lost efficacy; in the situation that breaking down; for realizing, data are protected fast; in TM-SPRing, following two protection mechanisms are formulated, source routing (Steering) mode and loopback (Wrapping) mode.

Wrapping protected mode is network failure to be detected when the node on network, and fault side adjacent node sends switching request by APS agreement to adjacent node.Lost efficacy or received switching request when certain node detects, the business that is forwarded to failure node will arrive another direction.

In the time that network is normally worked, node A flows to the path of node D as shown in Figure 1; break down in path between network node C and node D; Wrapping protected mode is that data are walked around malfunctioning node; 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.By the method for loop-back path, make business datum pick up the applicable path of bar.The method shortcoming of processing network failure by this Wrapping protected mode is due to loopback malfunctioning node, can make path increase, and the path of route is not optimized path.

Steering protection refers in the time that network detects network failure, sends switching request by all nodes on APS agreement ring.Each source node of the connection of point-to-point is carried out and is switched, and all T-MPLS connections that are subject to network failure impact are switched to protection direction from operative orientation, and when after network failure or the disappearance of APS agreement, all affected business recoveries are to original path.As shown in Figure 3, when network detects while breaking down between node C and node D, no longer sent to node D through Node B and node C by the data of node A, but be directly switched on another paths.The weak point of this reverse method is, 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, solve traditional Wrapping protected mode path longer, the problem that Steering protected mode packet loss is higher.

Data guard method before the fault recovery of a kind of T-MPLS protection rings, described T-MPLS protection rings comprises the 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 occurs, front nodal point transmits data to posterior nodal point; Described data guard method comprises:

The data of transmission are divided into tdm data and non-tdm data two classes by start node, after fault occurs, start node carries out mark to the last frame data that send, then by tdm data buffer memory, non-tdm data is transferred to destination node (this mechanism can not affect the transmission of non-tdm data, has improved non-TDM business datum transmission efficiency) in opposite direction; Front nodal point transfers to destination node by the data acquisition receiving by the mode of loopback, in this process, in the time that start node receives the Frame of its self marker, the tdm data of buffer memory and the new data that receive is transferred to destination node in opposite direction;

Described rightabout is, with fault, the direction that between front start node and destination node, data transfer direction is contrary occurs.

Receive at start node after the data of its self marker, the data of its transmission comprise the tdm data of buffer memory, new tdm data and the non-tdm data receiving.

Preferably, the first frame data that before described front nodal point occurs the fault receiving, start node sends carry out mark, like this.

The present invention combines the advantage of having utilized loopback protected mode and source routing protected mode; by issued start node data acquisition loopback protected mode; reduce packet loss, in addition the data acquisition sending start node buffer memory and new has been protected by source routing mode, optimized transmission path.

Accompanying drawing explanation

When Fig. 1 normally works, node A is to the data flow schematic diagram of node D;

Fig. 2 node C node D Wrapping protected mode schematic diagram that breaks down;

Steering protected mode schematic diagram when Fig. 3 node C node D breaks down;

Fig. 4 protects 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, between adjacent two nodes, can realize two-way communication.The management maintenance module of communication system periodically detects the connection status of looped network, can detect by connectivity, the form such as loopback detection.

If fault do not detected; illustrate that network is in normal operating state; enter next sense cycle; if the fault of detecting; the situations such as opening circuit appears in loop are described, at this moment two end nodes of failure path start to send out protection request, APS information notice interdependent node; and communicate by letter with another malfunctioning node, complete switching of Loopback Mode.

As shown in Figure 2; now the path of transfer of data is node A-Node B-node C-node D; between detection node C and node D, break down; node C and node D start to send protection claim frame; by 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 to receive the reserved byte mark of Frame.

As shown in Figure 4, Frame generally comprises the parts such as function type, tag head, reserved byte and data message, latter two byte of the reserved byte of node C first frame data of receiving after fault occurs is made as " 01 ", data acquisition after simultaneously fault being occurred transfers to node D with Loopback Mode, 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 is generally that node transmits to next node; and its content territory ID of comprising start node and the ID of destination node; next node is being received after protection claim frame; can compare with self ID; if not start node or destination node; can transmit down by protection claim frame, until originating node receives after this claim frame, stop to next node transmission.

When start node is received after protection claim frame; now the data of transmission are divided into two classes by start node; wherein tdm data buffer memory; suspend and send; but not tdm data continues to transfer in opposite direction node D; the last frame data that send are carried out to mark, labeling method is that last two in reserved byte are made as " 11 " simultaneously.

As shown in Figure 3; in the time that node A receives the first frame data of node C mark; start to prepare switch protecting mode; because now show that the last frame data of its mark also will arrive; receive the last frame data of its mark to node A; the tdm data of buffer memory and the new data that receive are transferred in opposite direction node D by node A, is switched to source routing protected mode.

Claims

1. the data guard method before T-MPLS protection rings fault recovery, described T-MPLS protection rings comprises the 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 occurs, front nodal point transmits data to posterior nodal point; Described data guard method comprises:

The data of transmission are divided into tdm data and non-tdm data two classes by start node, and after fault occurs, start node carries out mark to the last frame data that send, and then by tdm data buffer memory, non-tdm data is transferred to destination node in opposite direction; Front nodal point transfers to destination node by the data acquisition receiving by the mode of loopback, in this process, in the time that start node receives the Frame of its self marker, the tdm data of buffer memory and the new data that receive is transferred to destination node in opposite direction.

2. data guard method according to claim 1, is characterized in that, the first frame data that before described front nodal point occurs the fault receiving, start node sends carry out mark.