CN101192990A

Movatterモバイル変換

Info

Publication number: CN101192990A
Application number: CNA2006101611313A
Authority: CN
Inventors: 张海燕
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-11-30
Filing date: 2006-11-30
Publication date: 2008-06-04
Also published as: WO2008064612A1

Abstract

Translated fromChinese

本发明提供了一种MPLS网络中实现快速重路由的方法及设备及系统，属于通信领域。本发明主要包括：在环拓扑上，由保护LSP(标签交换路径)的源节点沿保护环方向与工作LSP宿节点间建立保护LSP，以便于可以利用该保护LSP实现快速重路由环保护。因此，本发明仅通过在环拓扑中建立的一条保护LSP即可实现对多个节点和链路的快速重路由保护，而无需如现有技术一样建立多条保护LSP对多个节点和链路进行保护，因而可以有效减少节点设备中信息的存储量，并可以减少实现快速重路由保护方案过程中对带宽资源的占用量。

The invention provides a method, equipment and system for realizing fast rerouting in an MPLS network, belonging to the communication field. The invention mainly includes: on the ring topology, the source node of the protection LSP (label switching path) establishes the protection LSP along the direction of the protection ring and the sink node of the working LSP, so that the protection LSP can be used to realize fast rerouting ring protection. Therefore, the present invention can realize fast rerouting protection to multiple nodes and links only through one protection LSP established in the ring topology, without establishing multiple protection LSPs for multiple nodes and links as in the prior art Therefore, the amount of information stored in the node device can be effectively reduced, and the amount of bandwidth resources occupied in the process of implementing the fast rerouting protection scheme can be reduced.

Description

Translated fromChinese

一种MPLS网络中实现快速重路由的方法及设备及系统Method, device and system for realizing fast rerouting in MPLS network

技术领域technical field

本发明涉及网络通信技术领域，尤其涉及一种针对MPLS(多协议标签交换)实现快速重路由的方法及系统。The invention relates to the technical field of network communication, in particular to a method and system for realizing fast rerouting for MPLS (Multi-Protocol Label Switching).

背景技术Background technique

MPLS是一种用于快速数据包交换和路由的体系，其为网络数据流量提供了目标、路由、转发和交换等能力。为提高MPLS网络的信息传递的可靠性，IETF(互联网工程任务组)组织提出了快速重路由机制。所述的快速重路由技术借助MPLS流量工程的能力，为LSP(标签交换路径)提供快速保护倒换能力。MPLS is a system for fast data packet switching and routing, which provides the capabilities of destination, routing, forwarding and switching for network data traffic. In order to improve the reliability of information transmission in the MPLS network, the IETF (Internet Engineering Task Force) organization proposed a fast rerouting mechanism. The fast rerouting technology uses the capability of MPLS traffic engineering to provide fast protection switching capability for LSP (Label Switching Path).

MPLS快速重路由的具体实现过程包括：预先建立本地备份路径作为保护LSP，所述的保护LSP要求不会受链路或节点故障的影响，这样，当故障发生时，检测到链路或节点故障的设备就可以快速将业务切换到所述作为备份路径的保护LSP上，从而减少经由MPLS网络传输的数据丢失量。The specific implementation process of MPLS fast rerouting includes: pre-establishing a local backup path as a protection LSP, the protection LSP requires that it will not be affected by link or node failures, so that when a failure occurs, the link or node failure is detected The device can quickly switch the service to the protection LSP as the backup path, thereby reducing the amount of data loss transmitted through the MPLS network.

MPLS快速重路由具有可以迅速响应、及时切换的特点，因此，其可以保证业务数据的平滑过渡，而不会导致业务中断；同时，LSP的源节点会尝试寻找新的路径来重新建立LSP，并将数据切换到新路径上；在新的LSP建立成功之前，业务数据会一直通过保护路径转发。MPLS fast rerouting has the characteristics of quick response and timely switching, so it can ensure the smooth transition of service data without causing service interruption; at the same time, the source node of the LSP will try to find a new path to re-establish the LSP, and Switch the data to the new path; before the new LSP is successfully established, the service data will always be forwarded through the protection path.

IETF的MPLS工作组在其制定的标准草案RFC4090中对RSVP-TE(资源预留扩展协议)信令进行了扩展，增添了实现线性点到点LSP快速重路由的1∶1保护方式。The MPLS working group of IETF expands the RSVP-TE (Resource Reservation Extension Protocol) signaling in its standard draft RFC4090, and adds a 1:1 protection mode to realize linear point-to-point LSP fast rerouting.

所述1∶1保护方式的保护方案为：为被保护的LSP中的每个潜在的本地修复点创建一条保护路径。The protection scheme of the 1:1 protection mode is: create a protection path for each potential local restoration point in the protected LSP.

在1∶1保护方式中，通过基于流量工程的RSVP-TE信令建立一条工作LSP，且建立信令中携带其对保护的需求以及所需的保护LSP的属性。工作LSP上的每个节点都是潜在的PLR(本地修复节点)，根据工作LSP的信令和本地策略，PLR计算并建立由本PLR至工作LSP宿节点的保护LSP，以保护其下游链路和节点。In the 1:1 protection mode, a working LSP is established through RSVP-TE signaling based on traffic engineering, and the establishment signaling carries its protection requirements and the attributes of the required protection LSP. Each node on the working LSP is a potential PLR (Local Repair Node). According to the signaling and local policies of the working LSP, the PLR calculates and establishes a protection LSP from this PLR to the sink node of the working LSP to protect its downstream links and node.

如图1所示，工作LSP的路径为：[R1，R2，R3，R4，R5，R6]，相应的保护LSP包括以下两条：As shown in Figure 1, the path of the working LSP is: [R1, R2, R3, R4, R5, R6], and the corresponding protection LSP includes the following two:

备用LSP1，其路径为[R2，R7，R8，R9，R4，R5，R6]，可以在R2节点至R4节点之间出现故障时提供保护；Standby LSP1, whose path is [R2, R7, R8, R9, R4, R5, R6], can provide protection when there is a failure between the R2 node and the R4 node;

备用LSP2，其路径为[R3，R8，R9，R5，R6]，其可以在R3节点至R5节点之间出现故障时提供保护。The backup LSP2, whose path is [R3, R8, R9, R5, R6], can provide protection when a failure occurs between the R3 node and the R5 node.

上述现有重路由保护技术在应用于环拓扑网络时，可实现点到点的LSP快速重路由，但是，不难看出，现有技术中为对工作LSP实现保护，需要在工作LSP除宿节点外的每个节点都为其下游链路或节点建立相应的保护LSP，因此，若提供可靠保护则需要建立多条保护LSP，这必然导致为工作LSP提供保护过程中存在着实现复杂、占用网络资源较多的问题。When the above-mentioned existing rerouting protection technology is applied to a ring topology network, it can realize point-to-point LSP fast rerouting. However, it is not difficult to see that in the prior art, in order to protect the working LSP, it is necessary to remove the destination node of the working LSP Each node outside the network establishes a corresponding protection LSP for its downstream links or nodes. Therefore, to provide reliable protection, it is necessary to establish multiple protection LSPs, which will inevitably lead to complex implementation and network occupation in the process of providing protection for working LSPs. problem with more resources.

发明内容Contents of the invention

本发明提供了一种MPLS网络中实现快速重路由的方法及设备及系统，从而可以较为简便地在MPLS网络中实现快速重路由，为LSP提供保护。The invention provides a method, equipment and system for realizing fast rerouting in the MPLS network, so that the fast rerouting can be realized in the MPLS network relatively easily, and LSP can be protected.

本发明提供了一种MPLS网络中实现快速重路由的方法，该方法应用于MPLS网络中，且该方法包括：The invention provides a method for realizing fast rerouting in an MPLS network, the method is applied in the MPLS network, and the method includes:

在环拓扑上，以工作LSP上的节点作为保护LSP的源节点，自该源节点起沿工作LSP反方向建立与工作LSP宿节点间的保护LSP，利用建立的保护LSP对工作LSP实现快速重路由保护。In the ring topology, the node on the working LSP is used as the source node of the protection LSP, and the protection LSP between the working LSP sink node and the working LSP is established from the source node along the opposite direction of the working LSP, and the working LSP is quickly re-established by the established protection LSP. Route protection.

本发明还提供了一种实现快速重路由的节点设备，该设备用于MPLS网络中，且包括：The present invention also provides a node device for realizing fast rerouting, which is used in an MPLS network and includes:

保护LSP建立单元，用于进行保护LSP建立消息的传递，以控制沿工作LSP反方向建立本地与工作LSP宿节点间的保护LSP；The protection LSP establishment unit is used to transmit the protection LSP establishment message, so as to control the establishment of the protection LSP between the local and the working LSP sink node along the reverse direction of the working LSP;

保护处理单元，用于在工作LSP出现故障后，利用保护LSP建立单元建立的保护LSP对工作LSP实现快速重路由保护。The protection processing unit is configured to use the protection LSP established by the protection LSP establishment unit to implement fast rerouting protection for the working LSP after the working LSP fails.

本发明还提供了一种MPLS网络中实现快速重路由的系统，该系统设置于MPLS网络中，该系统包括：The present invention also provides a system for realizing fast rerouting in an MPLS network, the system is set in the MPLS network, and the system includes:

保护LSP建立单元，设置于各个环拓扑的节点中，用于以工作LSP上的节点作为保护LSP的源节点，自该源节点起沿工作LSP反方向建立与工作LSP宿节点间保护LSP；The protection LSP establishment unit is set in each node of the ring topology, and is used to use the node on the working LSP as the source node of the protection LSP, and establish a protection LSP between the working LSP sink node and the working LSP from the source node in the opposite direction of the working LSP;

保护处理单元，设置于环拓扑的多个节点中，用于在工作LSP出现故障后，利用建立的保护LSP对工作LSP进行保护实现快速重路由保护。The protection processing unit is arranged in multiple nodes of the ring topology, and is used to protect the working LSP by using the established protection LSP to realize fast rerouting protection after the working LSP fails.

由上述本发明提供的技术方案可以看出，本发明在环拓扑中建立一条保护LSP即可实现对多个节点和链路的快速重路由保护，无需建立多条保护LSP对多个节点和链路进行保护，因此，本发明的实现显然可以使得在为MPLS网络中的工作LSP提供保护过程中可以有效减少保护链路信息的存储量，进而也可以有效减少对网络中的带宽资源的占用。而且，由于无需建立多条保护LSP，故还可以有效减少MPLS网络中控制平面的处理开销，从而有效提高保护倒换的处理效率，进而提高整个网络的通信性能。As can be seen from the technical solution provided by the present invention above, the present invention can realize fast rerouting protection for multiple nodes and links by establishing a protection LSP in the ring topology, without establishing multiple protection LSPs for multiple nodes and links. Therefore, the implementation of the present invention can obviously reduce the storage amount of protection link information in the process of providing protection for the working LSP in the MPLS network, and then can effectively reduce the occupation of bandwidth resources in the network. Moreover, since there is no need to establish multiple protection LSPs, the processing overhead of the control plane in the MPLS network can be effectively reduced, thereby effectively improving the processing efficiency of protection switching, and further improving the communication performance of the entire network.

附图说明Description of drawings

图1所示为现有技术一中的保护示意图；FIG. 1 is a schematic diagram of protection inprior art 1;

图2所示为本发明实施例一的保护LSP建立流程图；FIG. 2 is a flow chart of establishing a protection LSP inEmbodiment 1 of the present invention;

图3所示为本发明实施例二的保护LSP建立示意图；FIG. 3 is a schematic diagram of establishing a protection LSP inEmbodiment 2 of the present invention;

图4所示为本发明实施例二中发生故障后，保护LSP进行倒换的示意图；FIG. 4 is a schematic diagram of protection LSP switching after a fault occurs inEmbodiment 2 of the present invention;

图5为本发明所述的节点设备的实施例结构示意图。Fig. 5 is a schematic structural diagram of an embodiment of a node device according to the present invention.

具体实施方式Detailed ways

本发明应用于环拓扑上，具体可以由工作环中的保护LSP的源节点沿保护环方向与工作LSP宿节点间建立保护LSP，实现快速重路由环保护。The present invention is applied to the ring topology. Specifically, the protection LSP can be established between the source node of the protection LSP in the working ring and the sink node of the working LSP along the direction of the protection ring, so as to realize fast rerouting ring protection.

具体一点讲，在本发明所述的环拓扑中的重路由保护的实现方案中，具体包括以下处理过程：Specifically, in the implementation scheme of the rerouting protection in the ring topology of the present invention, the following processing procedures are specifically included:

首先，需要在建立工作LSP的过程中，向工作LSP中的各节点通告保护属性，并确定保护LSP的源节点。First, in the process of establishing the working LSP, it is necessary to notify the protection attributes to each node in the working LSP, and determine the source node of the protection LSP.

在确定保护LSP的源节点后，在保护环上沿工作LSP的反方向，建立由所述保护LSP的源节点至保护LSP宿节点的保护LSP。After the source node of the protection LSP is determined, a protection LSP from the source node of the protection LSP to the sink node of the protection LSP is established along the reverse direction of the working LSP on the protection ring.

在建立所述保护LSP的过程中，PLR需要绑定工作LSP和保护LSP的转发关系，以备后续保护倒换应用。In the process of establishing the protection LSP, the PLR needs to bind the forwarding relationship between the working LSP and the protection LSP for subsequent application of protection switching.

在保护LSP成功建立后，当工作LSP的链路或节点出现故障，则检测到故障或接收到故障信息的节点进行保护倒换，通过保护LSP将业务转发至工作LSP的宿节点，在环拓扑内实现对业务的保护。After the protection LSP is successfully established, when the link or node of the working LSP fails, the node that detects the failure or receives the failure information performs protection switching, forwards the service to the sink node of the working LSP through the protection LSP, and in the ring topology Realize the protection of the business.

下面将结合本发明具体实施例附图对本发明作详细说明。The present invention will be described in detail below in conjunction with the accompanying drawings of specific embodiments of the present invention.

如图2所示，本发明实施例一提供的保护LSP的建立流程具体可以包括如下步骤：As shown in FIG. 2 , the establishment process of the protection LSP provided byEmbodiment 1 of the present invention may specifically include the following steps:

步骤1、源节点向宿节点发起携带有保护属性的工作LSP建立消息，宿节点回复工作LSP建立响应消息，建立工作LSP。Step 1. The source node sends a working LSP establishment message carrying protection attributes to the sink node, and the sink node replies with a working LSP establishment response message to establish a working LSP.

在本实施例一的环拓扑中，源节点向宿节点发起工作LSP建立消息，请求与宿节点建立工作LSP，并在所述的工作LSP建立消息中携带保护属性，该消息经工作LSP的各节点转发至宿节点。In the ring topology ofEmbodiment 1, the source node initiates a working LSP establishment message to the sink node, requests to establish a working LSP with the sink node, and carries protection attributes in the working LSP establishment message, and the message is passed through each The node forwards to the sink node.

本实施例一中具体可以以路径消息(Path Message)作为工作LSP建立消息；Specifically, in this embodiment one, a path message (Path Message) can be used as a working LSP establishment message;

所述的保护属性可以包括：本地保护需求、节点保护需求、带宽保护需求、保护LSP属性以及环保护属性等；The protection attributes may include: local protection requirements, node protection requirements, bandwidth protection requirements, protection LSP attributes, ring protection attributes, etc.;

宿节点接收工作LSP建立消息，向源节点回复工作LSP响应消息，源节点与宿节点之间建立起工作LSP；The sink node receives the working LSP establishment message, replies the working LSP response message to the source node, and establishes the working LSP between the source node and the sink node;

本实施例中所述的宿节点回复工作LSP建立响应消息可以为预留消息(Resv Message)。In this embodiment, the sink node replies to the working LSP establishment response message may be a reservation message (Resv Message).

完成上述工作LSP的建立后，便可以根据建立的工作LSP进行相应的保护LSP的建立操作，具体的处理过程如下：After the establishment of the above working LSP is completed, the establishment of the corresponding protection LSP can be performed according to the established working LSP. The specific processing process is as follows:

步骤2、收到LSP建立消息的节点确定其是否为工作LSP上的非宿节点，若该节点为工作LSP上节点，且为相应的非宿节点，则执行步骤3；若该节点为工作LSP上的宿节点，或该节点为非工作LSP上的节点，则执行步骤6；Step 2. The node receiving the LSP establishment message determines whether it is a non-destination node on the working LSP. If the node is a node on the working LSP and the corresponding non-sink node, then performstep 3; if the node is a working LSP or the node on the non-working LSP, go tostep 6;

在环拓扑上的节点收到LSP建立的消息后，由于该LSP建立消息可能是建立工作LSP的消息，也可能是建立保护LSP的消息，因此，在节点上需要根据该节点是否为工作LSP上的非宿节点确定针对相应的消息的处理方式，其中，包括针对建立保护LSP的消息的处理；After the nodes on the ring topology receive the LSP establishment message, since the LSP establishment message may be a message to establish a working LSP or a message to establish a protection LSP, the node needs to determine whether the node is a working LSP or not. The non-destination node determines the processing mode for the corresponding message, which includes the processing for the message of establishing the protection LSP;

其中，环拓扑上接收到工作LSP的Path Message消息的节点是工作LSP上的节点，环上其它节点非工作LSP上的节点；Wherein, the node on the ring topology that receives the Path Message message of the working LSP is a node on the working LSP, and other nodes on the ring are nodes on the non-working LSP;

在确定工作LSP的节点后，则进一步根据工作LSP的路径消息(PathMessage)或预留消息(Resv Message)中携带的信息确定本节点是否为工作LSP的宿节点，以实现该步骤的相应处理；After determining the node of the working LSP, then further determine whether this node is the sink node of the working LSP according to the information carried in the path message (PathMessage) of the working LSP or the reserved message (Resv Message), to realize the corresponding processing of this step;

步骤3、检测工作LSP的各非宿节点是否保护LSP的源节点；Step 3, detecting whether each non-destination node of the working LSP protects the source node of the LSP;

在具体应用本发明过程中，可以选择工作LSP上宿节点以外的任意节点作为保护LSP的源节点；In the specific application process of the present invention, any node other than the sink node on the working LSP can be selected as the source node of the protection LSP;

具体的工作LSP上的各非宿节点确定保护LSP源节点的方式可以包括：建立工作LSP时，可以在源节点发送的建立消息或宿节点发送的响应消息中携带保护LSP的源节点信息；或由网络管理方根据对工作LSP的保护需要指定一个节点为保护LSP的源节点，并将该节点直接配置为保护LSP的源节点，例如将工作LSP中的倒数第二跳设为保护LSP的源节点；The specific way for each non-sink node on the working LSP to determine the source node of the protection LSP may include: when establishing the working LSP, the source node information of the protection LSP may be carried in the establishment message sent by the source node or the response message sent by the sink node; or The network management side designates a node as the source node of the protection LSP according to the protection needs of the working LSP, and directly configures the node as the source node of the protection LSP, for example, setting the penultimate hop in the working LSP as the source of the protection LSP node;

工作LSP的各非宿节点通过上述方法获得保护LSP的源节点信息，便可以判断本节点是否为保护LSP的源节点，且：Each non-destination node of the working LSP obtains the source node information of the protection LSP through the above method, and then can judge whether the node is the source node of the protection LSP, and:

当工作LSP上宿节点外的一节点为保护LSP的源节点，则执行步骤4；When a node other than the sink node on the working LSP is the source node of the protection LSP, performstep 4;

当工作LSP上宿节点外的一节点为保护LSP的非源节点，则执行步骤5；When a node other than the sink node on the working LSP is a non-source node of the protection LSP, performstep 5;

步骤4、保护LSP的源节点建立保护LSP；Step 4, the source node of the protection LSP establishes the protection LSP;

当工作LSP上宿节点外的一个节点为保护LSP的源节点，则该节点在保护环上沿工作环的反方向，向宿节点发送保护LSP建立消息；When a node other than the sink node on the working LSP is the source node of the protection LSP, the node sends a protection LSP establishment message to the sink node along the opposite direction of the working ring on the protection ring;

同时，保护LSP的源节点作为PLR执行步骤7。At the same time, the source node of the protected LSP acts as the PLR to performstep 7.

步骤5、工作LSP上宿节点外的节点接收到保护LSP的Path Message或Resv Message，若该节点非保护LSP的源节点，则直接向下游或上游转发接收到的保护LSP的消息。Step 5. A node other than the sink node on the working LSP receives the Path Message or Resv Message of the protection LSP. If the node is not the source node of the protection LSP, it forwards the received protection LSP message downstream or upstream directly.

同时，根据本地策略确定本节点是否作为PLR，若本节点需要作为PLR，则执行步骤7；否则，无需执行步骤7，直接转发相应的消息即可。At the same time, according to the local policy, it is determined whether the current node is a PLR. If the current node needs to be a PLR,step 7 is performed; otherwise,step 7 is not required, and the corresponding message can be forwarded directly.

步骤6、作为普通LSP建立处理，并执行步骤8；Step 6, establish processing as a common LSP, and performstep 8;

环上非工作LSP上的节点直接向下游或上游转发接收到的保护LSP的消息；工作LSP上的宿节点在接收到保护LSP建立消息后，向上游发送保护LSP的响应消息。The nodes on the non-working LSP on the ring directly forward the received protection LSP message downstream or upstream; the sink node on the working LSP sends a protection LSP response message upstream after receiving the protection LSP establishment message.

步骤7、由保护LSP的源节点起，至保护LSP宿节点为止，并在环拓扑中作为PLR的节点绑定工作LSP和保护LSP的转发关系，并执行步骤8；Step 7. From the source node of the protection LSP to the sink node of the protection LSP, bind the forwarding relationship between the working LSP and the protection LSP as a node of the PLR in the ring topology, and performstep 8;

在建立保护LSP的过程中，PLR将所述Path Message和Resv Message中携带的被分配的标签和相应的出接口信息映射到工作LSP的相应转发表中，在PLR中实现工作LSP和保护LSP关系的绑定。In the process of establishing the protection LSP, the PLR maps the assigned labels and corresponding outgoing interface information carried in the Path Message and Resv Message to the corresponding forwarding table of the working LSP, and realizes the relationship between the working LSP and the protection LSP in the PLR binding.

本实施例中所述保护LSP建立消息和保护LSP建立响应消息中携带显式路由，该显式路由限定在保护环里。In this embodiment, the protection LSP establishment message and the protection LSP establishment response message carry an explicit route, and the explicit route is limited in the protection ring.

步骤8、至此，工作LSP的保护LSP在环拓扑中成功建立。Step 8. So far, the protection LSP of the working LSP is successfully established in the ring topology.

步骤9、PLR将经过更新的保护状态上报给工作LSP的源节点。Step 9: The PLR reports the updated protection status to the source node of the working LSP.

在上述各步骤中，环拓扑中的各个节点在所使用的标签空间类型上，可以选择基于平台的标签空间或基于接口的标签空间。In each of the above steps, each node in the ring topology can select a platform-based label space or an interface-based label space as the type of label space used.

若采用基于平台的标签空间，且一条LSP要采用唯一的标签进行标识，则工作和保护LSP的唯一标签要求不能相同；If a platform-based label space is used, and an LSP needs to be identified with a unique label, the unique label requirements for the working and protection LSPs cannot be the same;

若采用除上述情况外的基于平台的标签空间或基于接口的标签空间的情况，则无上述限制，一条LSP每跳的标签无约束，且工作和保护LSP间的标签无任何约束。If the platform-based label space or interface-based label space is adopted, there are no restrictions above, and there is no restriction on the label per hop of an LSP, and there is no restriction on the label between the working and protection LSPs.

为对本发明的内容进行详细说明，现选取一个工作LSP的节点作为保护LSP的源点，对保护LSP的建立以及保护倒换处理进行具体介绍。In order to describe the content of the present invention in detail, a node of a working LSP is selected as the source point of the protection LSP, and the establishment of the protection LSP and the protection switching process are specifically introduced.

如图3所示，为本发明实施例二的保护LSP建立示意图，该图中选择工作LSP的倒数第二跳作为保护LSP的源节点。As shown in FIG. 3 , it is a schematic diagram of establishing a protection LSP according toEmbodiment 2 of the present invention. In this figure, the penultimate hop of the working LSP is selected as the source node of the protection LSP.

如图3所示，节点3为工作LSP的源节点，节点8为工作LSP的宿节点，节点7为保护LSP的源节点，是工作LSP的倒数第二跳节点。As shown in FIG. 3 ,node 3 is the source node of the working LSP,node 8 is the sink node of the working LSP, andnode 7 is the source node of the protection LSP, which is the penultimate hop node of the working LSP.

节点7通过工作LSP的Path Message中携带的保护属性确定在该工作LSP中要求由倒数第二跳发起保护LSP的建立，且节点7通过Resv Message中携带的显式路由[3，4，5，6，7，8]判断出本节点为工作LSP的倒数第二跳，因此，节点7沿保护环(逆时针)方向发起Path Message，即沿工作环(顺时针)的反向发起Path Message，建立保护LSP。Node 7 determines through the protection attribute carried in the Path Message of the working LSP that the establishment of the protection LSP is required to be initiated by the penultimate hop in the working LSP, andnode 7 uses the explicit route carried in the Resv Message [3, 4, 5, 6, 7, 8] It is judged that this node is the penultimate hop of the working LSP, therefore,node 7 initiates a Path Message along the direction of the protection ring (counterclockwise), that is, initiates a Path Message along the reverse direction of the working ring (clockwise), Establish a protection LSP.

同时节点7作为PLR，将保护LSP的消息Path Message或Resv Message中分配的标签和相应的出接口信息，映射到工作LSP的相应转发表中，绑定工作LSP和保护LSP的转发关系。At the same time,node 7, as a PLR, maps the label and corresponding outgoing interface information allocated in the Path Message or Resv Message of the protection LSP to the corresponding forwarding table of the working LSP, and binds the forwarding relationship between the working LSP and the protection LSP.

该保护LSP的Path Message中携带的显式路由限定在保护环里，即[7，6，5，4，3，2，1，8]，其源节点为工作LSP的倒数第二跳节点7，宿节点为工作LSP的宿节点8。The explicit route carried in the Path Message of the protection LSP is limited to the protection ring, namely [7, 6, 5, 4, 3, 2, 1, 8], and its source node is thepenultimate hop node 7 of the working LSP , the sink node is thesink node 8 of the working LSP.

节点6通过工作LSP的Resv Message中携带的显式路由[3，4，5，6，7，8]判断出本节点非工作LSP的倒数第二跳，则节点6向下游节点5转发接收到的保护LSP的Path Message，当收到反向的基于该保护LSP的Resv Message时则向上游转发相应消息。Node 6 judges the penultimate hop of the node's non-working LSP through the explicit route [3, 4, 5, 6, 7, 8] carried in the Resv Message of the working LSP, thennode 6 forwards the received message todownstream node 5 The Path Message of the protected LSP, when receiving the reverse Resv Message based on the protected LSP, forwards the corresponding message upstream.

节点6根据本地策略确定本节点作为PLR，将保护LSP的消息(PathMessage或Resv Message)中分配的标签和相应的出接口信息，映射到工作LSP的相应转发表中，绑定工作LSP和保护LSP的转发关系。Node 6 determines the node as the PLR according to the local policy, and maps the label and corresponding outgoing interface information allocated in the message (PathMessage or Resv Message) of the protection LSP to the corresponding forwarding table of the working LSP, and binds the working LSP and the protection LSP forwarding relationship.

环中其他节点5、4、3若作为PLR则可以采用与节点6的处理相同，故不一一说明。If theother nodes 5, 4, and 3 in the ring serve as PLRs, they can adopt the same processing as that ofnode 6, so they will not be described one by one.

环上的其它非工作LSP上的节点，包括节点2、1，以及工作LSP的宿节点8，接收到保护LSP的消息后，与普通LSP的建立处理一致。The nodes on other non-working LSPs on the ring, includingnodes 2 and 1, and thesink node 8 of the working LSP, after receiving the message of the protection LSP, are consistent with the establishment process of the common LSP.

在宿节点8收到保护LSP的Path Message后，其将沿节点[8，1，2，3，4，5，6，7]返回Resv Message至倒数第二跳节点7，保护LSP成功建立。Aftersink node 8 receives the Path Message of the protection LSP, it will return a Resv Message along the nodes [8, 1, 2, 3, 4, 5, 6, 7] to thepenultimate hop node 7, and the protection LSP is successfully established.

PLR通过工作LSP的Resv Message中RRO Sub-Object携带的状态指示位，向工作LSP的源节点上报保护LSP的状态，包括本地保护是否可用、本地保护是否已启用、是否提供带宽保护、是否环保护等。The PLR reports the status of the protection LSP to the source node of the working LSP through the status indication bit carried by the RRO Sub-Object in the Resv Message of the working LSP, including whether local protection is available, whether local protection is enabled, whether bandwidth protection is provided, and whether ring protection is available wait.

如图4所示为本发明实施例二中，当节点5、6间链路发生故障后，进行保护倒换的工作示意图。As shown in FIG. 4 , in the second embodiment of the present invention, when the link betweennodes 5 and 6 fails, the working diagram of protection switching is performed.

本发明实施例在对工作LSP进行保护时，具有多种保护倒换方法。The embodiment of the present invention has multiple protection switching methods when protecting the working LSP.

故障的上游节点5检测到故障，发起保护倒换，故障LSP对应的转发表中相应倒换状态置位，后续节点5接收到的相应业务按转发表的索引交换标签，并按相应出接口转发，保护倒换后业务的路由为[3，4，5，4，3，2，1，8]；The faultyupstream node 5 detects a fault and initiates protection switching. The corresponding switching status in the forwarding table corresponding to the faulty LSP is set. The route of the service after switching is [3, 4, 5, 4, 3, 2, 1, 8];

或，故障上游节点5检测到故障，通过保护环向源节点3发送告警信息，源节点3收到告警信息后发起保护倒换，故障LSP对应的转发表中相应倒换状态置位，后续源节点3发送的相应业务按转发表的索引交换标签，并按相应出接口转发。保护倒换后业务的路由为[3，2，1，8]；Or, the faultyupstream node 5 detects a fault, and sends an alarm message to thesource node 3 through the protection ring, and thesource node 3 initiates protection switching after receiving the alarm message, and the corresponding switching status is set in the forwarding table corresponding to the faulty LSP, and thesubsequent source node 3 The corresponding services sent are exchanged according to the index of the forwarding table, and forwarded according to the corresponding outgoing interface. The route of the service after protection switching is [3, 2, 1, 8];

或，故障上游节点5检测到故障，发起保护倒换，业务的路由为[3，4，5，4，3，2，1，8]。同时通过保护环向源节点3发送告警信息，源节点3收到告警信息后发起保护倒换，故障LSP对应的转发表中相应倒换状态置位，后续源节点3发送的相应业务按转发表的索引交换标签，并按相应出接口转发。保护倒换后业务的路由为[3，2，1，8]。Or, the faultyupstream node 5 detects a fault, initiates protection switching, and the route of the service is [3, 4, 5, 4, 3, 2, 1, 8]. At the same time, the alarm information is sent to thesource node 3 through the protection ring. After receiving the alarm information, thesource node 3 initiates protection switching, the corresponding switching status is set in the forwarding table corresponding to the faulty LSP, and the corresponding services sent by thesubsequent source node 3 are based on the index of the forwarding table. Labels are exchanged and forwarded according to the corresponding outgoing interface. The route of the service after protection switching is [3, 2, 1, 8].

本发明中的保护LSP还可以由除宿节点之外的其他任意节点发起建立，其工作原理与上述保护LSP的工作原理相同，但是保护范围有所不同。The protection LSP in the present invention can also be initiated by any node except the sink node, and its working principle is the same as that of the above protection LSP, but the protection scope is different.

例如，当在如图3所示的环拓扑中，如果从节点5发起保护LSP，则无法保护从节点6下游链路至宿节点间发生的故障，但在最大限度上，仍能保护源点到节点6之间的故障。For example, in the ring topology shown in Figure 3, if theslave node 5 initiates a protection LSP, it cannot protect the fault that occurs between the downstream link from thenode 6 to the sink node, but it can still protect the source node to the maximum extent. to a failure betweennode 6.

虽然此时的保护范围不是最大，但是由于在实际的保护LSP应用中对保护范围的不同要求，该方法具有一定的实际意义。Although the protection range is not the largest at this time, due to the different requirements on the protection range in the actual protection LSP application, this method has certain practical significance.

本发明还提供了一种MPLS网络中实现快速重路由的系统，该系统设置于MPLS网络中，通过该系统可以为MPLS网络中已经建立的工作LSP建立相应的保护LSP以实现快速重路由保护，其具体实现结构包括设置于拓扑环上的一组节点设备，在各个节点设备的具体结构如图5所示，包括：The present invention also provides a system for realizing fast rerouting in an MPLS network, the system is set in the MPLS network, through which a corresponding protection LSP can be established for the established working LSP in the MPLS network to realize fast rerouting protection, Its specific implementation structure includes a group of node devices arranged on the topological ring, and the specific structure of each node device is shown in Figure 5, including:

(1)源节点确定单元(1) Source node determination unit

用于确定保护LSP的源节点，即设置工作LSP的各非宿节点中用于根据接收获得的保护LSP的源节点信息，确定作为保护LSP的源节点的节点设备；或，根据配置的信息确定工作LSP环中的作为保护LSP的源节点的节点设备；It is used to determine the source node of the protection LSP, that is, among each non-sink node of the working LSP, it is used to determine the node device as the source node of the protection LSP according to the received source node information of the protection LSP obtained; or, determine according to the configured information The node device in the working LSP ring as the source node of the protection LSP;

当确定自身为保护LSP的源节点时，则触发自身的保护LSP建立单元；When it is determined that it is the source node of the protection LSP, trigger its own protection LSP establishment unit;

(2)保护LSP建立单元(2) Protection LSP establishment unit

用于以工作LSP上的节点作为保护LSP的源节点，自该源节点起沿工作LSP反方向建立与工作LSP宿节点间的保护LSP；It is used to use the node on the working LSP as the source node of the protection LSP, and establish a protection LSP with the sink node of the working LSP along the opposite direction of the working LSP from the source node;

具体由保护LSP的源节点负责发起建立过程，其他保护LSP上的节点设备负责配合执行建立保护LSP的过程；Specifically, the source node of the protection LSP is responsible for initiating the establishment process, and other node devices on the protection LSP are responsible for cooperating with the implementation of the process of establishing the protection LSP;

(3)保护处理单元(3) Protection processing unit

用于在工作LSP发生故障后，利用建立的保护LSP对工作LSP进行保护实现快速重路由保护。It is used to protect the working LSP by using the established protection LSP to implement fast rerouting protection after the working LSP fails.

可以看出，上述系统中主要是由设置于拓扑环上的各节点设备构成，下面将结合图5对相应的可以实现快速重路由的节点设备的具体实现结构进行描述，该节点设备可以为保护LSP源节点的节点设备，也可以为保护LSP中间节点的节点设备，即该节点设备即为拓扑环上的任意节点设备，其具体结构包括保护LSP建立单元和保护处理单元，其中；It can be seen that the above-mentioned system is mainly composed of node devices arranged on topological rings. The specific implementation structure of corresponding node devices that can realize fast rerouting will be described below in conjunction with Figure 5. This node device can be used for protection The node device of the LSP source node may also be the node device of the protection LSP intermediate node, that is, the node device is any node device on the topology ring, and its specific structure includes a protection LSP establishment unit and a protection processing unit, wherein;

(1)所述的保护LSP建立单元具体包括：(1) The protection LSP establishment unit specifically includes:

保护LSP建立操作单元，用于沿与工作LSP相反的保护环方向，向工作LSP的宿节点发送或转发保护LSP建立消息，对于作为保护LSP的源节点的节点设备需要发起建立过程，即需要发送所述保护LSP建立的消息，对于作为保护LSP的中间节点的节点设备，则负责转发所述的保护LSP建立的消息，以建立相应的保护LSP；The protection LSP establishment operation unit is used to send or forward the protection LSP establishment message to the sink node of the working LSP along the direction of the protection ring opposite to the working LSP. For the node device as the source node of the protection LSP, it needs to initiate the establishment process, that is, it needs to send The message of establishing the protection LSP is responsible for forwarding the message of establishing the protection LSP for the node device as an intermediate node of the protection LSP, so as to establish a corresponding protection LSP;

保护LSP建立确认单元，用于接收工作LSP的宿节点返回的保护LSP建立响应消息，确定保护LSP建立。The protection LSP establishment confirmation unit is configured to receive the protection LSP establishment response message returned by the sink node of the working LSP, and determine the establishment of the protection LSP.

(2)所述的保护处理单元具体包括：(2) The protection processing unit specifically includes:

当确定本地节点设备为故障上游的PLR，则直接发起保护倒换，和/或，由故障上游的节点向工作LSP的源节点发送告警，以便于通过工作LSP的源节点发起保护倒换，具体的保护倒换实现过程前面已经有描述，故在此不再详述；When it is determined that the local node device is the upstream PLR of the fault, protection switching is directly initiated, and/or the upstream node of the fault sends an alarm to the source node of the working LSP, so as to initiate protection switching through the source node of the working LSP. The specific protection The switching implementation process has been described before, so it will not be described in detail here;

对于发生保护倒换的节点设备(可以为故障上游的PLR节点设备和/或工作LSP的源节点设备)，则对接收到的业务按转发表的索引交换标签，并按相应出接口转发，以实现对工作LSP的保护。For the node device where protection switching occurs (it can be the PLR node device upstream of the fault and/or the source node device of the working LSP), the received service is exchanged according to the index of the forwarding table and forwarded according to the corresponding outgoing interface, so as to realize Protection for working LSPs.

而且，本发明所述节点设备还可以包括转发关系存储单元，用于在所述保护LSP建立后，保存绑定的工作LSP与保护LSP的转发关系，所述转发关系用于进行保护倒换时使用。Moreover, the node device of the present invention may further include a forwarding relationship storage unit, configured to store the forwarding relationship between the bound working LSP and the protection LSP after the protection LSP is established, and the forwarding relationship is used for protection switching .

以上所述，仅为本发明较佳的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到的变化或替换，都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应该以权利要求的保护范围为准。The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.