WO2011020257A1

WO2011020257A1 - Method and apparatus for notifying failure lsp information

Info

Publication number: WO2011020257A1
Application number: PCT/CN2009/075162
Authority: WO
Inventors: 刘国满
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-08-21
Filing date: 2009-11-26
Publication date: 2011-02-24
Also published as: CN101997747B; CN101997747A

Abstract

The present invention discloses a method for notifying failure label switched path(LSP) information, which includes the following steps: the node in the ring network detecting the failure generates a status notification packet and sends it to other nodes in the ring network; according to the LSP information in the status notification packet, the node receiving the status notification packet judges whether the failure influences the services associated with the node itself or not, and when determining that the services are influenced, the path protection switching is implemented for the influenced services. The present invention also discloses an apparatus for notifying failure LSP information, enables the node in the ring network to acquire which services transmitted and received by the node itself are influenced by the failure, and therefore protects the services influenced by the failure in the ring network.

Description

Method and device for fault LSP information notification

The present invention relates to the field of operation management and maintenance (OAM) technology of a ring network, and in particular, to a method and apparatus for information disclosure of a faulty label switched path (LSP). Background technique

With the increasing number of Internet Protocol (IP) and data services for telecom services, the traditional Synchronous Digital Hierarchy (SDH) circuit-switched equipment is still in the utilization of channel resources. Flexibility and the suddenness of handling services are very problematic. Therefore, it is necessary to transform from SDH circuit switching technology to packet transmission network such as IP/Multi-Protocol Label Switching. The existing IP/MPLS data network has made great progress in handling the burstiness and flexibility of the service due to the use of packet switching technology, but when applied to the telecommunication bearer network, reliability, operation management and maintenance (OAM, There are some problems in the Operation Administration and Maintenance and the survival '1', so the fault detection mechanism and service protection functions are introduced in IP/MPLS to implement the bearer and transmission of the telecommunication service.

The MPLS ring network has a wide range of applications in practical networks due to its reliability and simplicity. There are many current MPLS ring protection methods, such as the wrapping and steering methods in G.8132. For the steering protection method, as shown in FIG. 1, when the service channel between the node 105 and the node 106 (shown by the solid line in the figure) fails, the node 105 or 106 that detects the failure first generates an automatic protection switching ( APS, Automatic Protection Switch) ^艮, and send the APS packet to other nodes on the ring network through the APS control channel (shown by the dotted line in the figure) to notify the fault status information. After receiving the APS packet, the other nodes on the ring network process and forward the APS packet. The node that receives the APS packet affects the node. The sending and receiving services are sent and received in the opposite direction of their working path.

There is a problem in the above protection method, that is, how the node that receives the APS message determines which services the fault is sent to and receives from the node. For example, in Figure 1, a service is a service from the sending node 101 along the direction of 101-102-103-104 to 104 nodes, and the corresponding label switched path (LSP, Label Switched Path) is recorded as LSP1, and another service is From the direction of the transmitting node 101 along the direction of 101-106-105-104 to the node of 104, the corresponding LSP is recorded as LSP2. For the link failure between the nodes 105 and 106, only the service corresponding to the LSP2 is affected, and the sending node 101 and the receiving node 104 need to send and receive services from the opposite direction of the working path; and the service corresponding to the LSP1 is not affected. This fault affects the need to switch paths. This requires the sending node 101 and the receiving node 104 to make a correct judgment only if it knows which LSPs of the service are affected by the failure. However, in the prior art, the nodes on the ring network cannot know which services the fault is transmitted and received by the node. Summary of the invention

In view of this, the main object of the present invention is to provide a method and apparatus for fault LSP information notification to solve the problem that a node on the ring network cannot know which services the fault has transmitted to and receives from the node.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides a method for advertised fault label switching path LSP information, the method comprising:

The node detecting the fault on the ring network generates a status advertisement message, and sends the status advertisement message to other nodes on the ring network;

The node that receives the status advertisement message determines whether the fault affects the related service according to the LSP information in the status advertisement packet, and performs a path on the affected service when determining the impact Protection switching.

The method further includes: detecting that the failed node will be affected by the faulty LSP information The LSP TLV packet is encapsulated into an LSP TLV packet, and the LSP TLV packet is encapsulated into a status advertisement packet generated by itself.

The method further includes: the node that receives the status advertisement message determines, according to the TLV offset Offset field of the status advertisement message, whether the LSP TLV message exists in the status advertisement message, and if not, does not process If yes, analyze the LSP TLV "^" in the status advertisement message.

The LSP TLV packet is analyzed, and the LSP ID information in the LSP TLV packet is compared with the LSP ID information of the service related to the node that receives the state advertisement packet, if the same exists. The LSP ID information determines that the fault has an impact on its own related service; otherwise, it determines that the fault has no impact on its related service.

The method further includes: when the fault is removed, the node that detects the fault is configured to notify the other node to switch the affected service to the path before the fault occurs by generating a status advertisement message that cancels the fault state.

The status advertisement message is an extended automatic protection switching APS message, or an operation management and maintenance OAM message.

The present invention also provides an apparatus for advertised fault LSP information, the apparatus comprising:

a message generation module, configured to generate a status advertisement for a node that detects a fault on the ring network, and a message receiving processing module, configured to receive a status advertisement message, and determine, according to the LSP information in the status advertisement message, Whether the fault affects its own related services, and when it is judged to have an impact, the path of the affected service is protected and switched.

The packet generating module is further configured to encapsulate the LSP information affected by the fault into an LSP TLV packet in a TLV format, and then encapsulate the LSP TLV packet into a status advertisement packet generated by the LSP.

The packet receiving processing module is further configured to: notify the TLV of the packet according to the status In the Offset field, it is determined whether the LSP TLV packet exists in the status advertisement packet, and if not, the LSP TLV packet in the status advertisement packet is analyzed.

The packet receiving processing module is further configured to compare the LSP ID information in the LSP TLV packet with the LSP ID information of the service related to the node that receives the status advertisement message, if the same LSP ID exists. The information determines that the fault has an impact on the service related to the node; otherwise, it determines that the fault has no impact on the service related to the node.

The message generating module is further configured to: when the node detects the fault elimination, generate a status notification message that cancels the fault state;

Correspondingly, the message sending module is further configured to send the status notification message of the fault elimination state to other nodes on the ring network, and notify other nodes to switch the affected service to the path before the fault occurs.

The status advertisement message is an extended APS message or a 0AM message.

The method and device for the notification of the faulty LSP information provided by the present invention, the node that detects the fault on the ring network generates a status advertisement message, and sends the status advertisement message to other nodes on the ring network; According to the LSP information in the status advertisement packet, the node determines whether the fault affects the related service, and performs protection switching on the affected service when the impact is determined. The invention realizes that the nodes on the ring network can know which services are sent and received by the fault, thereby realizing the protection of the service affected by the fault on the ring network. DRAWINGS

1 is a schematic structural view of a steering protection in the prior art;

2 is a flowchart of a method for notifying fault LSP information according to the present invention;

3 is a schematic structural diagram of an LSP TLV packet in the present invention;

4 is a schematic structural diagram of an extended APS message according to the present invention; FIG. 5 is a flowchart of a method for a fault LSP information channel according to an embodiment of the present invention; FIG. 6 is a schematic structural diagram of a device for notifying a fault LSP information according to the present invention. detailed description

The technical solutions of the present invention are further elaborated below in conjunction with the accompanying drawings and specific embodiments. The method for notifying the fault LSP information provided by the present invention, as shown in FIG. 2, mainly includes the following steps:

Step 201: The node that detects the fault on the ring network generates a status advertisement message, and sends the status advertisement message to other nodes on the ring network.

Step 202: The node that receives the status advertisement message determines whether the fault affects the related service according to the LSP information in the status advertisement packet, and performs protection switching on the affected service when the impact is determined.

Preferably, the node that detects the fault can encapsulate the LSP information affected by the fault into an LSP TLV packet in the form of a Type Length Value (TLV), and then encapsulate the LSP TLV packet. Go to the status notification message generated by itself. As shown in Figure 3, the LSP TLV packet structure includes a TYPE field, a length field, and an LSP ID field, where the LSP ID field is used to store LSP ID information affected by the fault.

In the status advertisement packet, the TLV offset (Offset) field is used to identify whether the LSP TLV packet exists in the status advertisement packet. Correspondingly, the node that receives the status advertisement packet advertises the TLV Offset according to the status advertisement packet. The field determines whether there is an LSP TLV packet in the status advertisement packet. If it does not exist, the LSP TLV packet is not processed. If yes, the LSP TLV packet in the status advertisement packet is analyzed. The LSP TLV packet analysis operation is performed by comparing the LSP ID (ID) information in the LSP TLV packet with the LSP ID information of the service related to the node receiving the status advertisement packet, if the same LSP exists. The ID information determines that the fault has an impact on its own related service; otherwise, it determines that the fault has no impact on its related business. The node that receives the status advertisement packet performs protection switching on the affected service. The affected transmit and receive services of this node are sent and received from the reverse direction of their current working path (ie, the protection path).

In addition, during troubleshooting, the node that detects the fault can also notify other nodes to switch the affected service to the path before the fault occurs by generating a status advertisement message that eliminates the fault status. The node that receives the status advertisement message that cancels the fault status switches all its services to the path before the fault occurs.

It should be noted that, in an actual application, the status advertisement message of the present invention may be an extended APS message or an OAM message. Of course, the status advertisement message of the present invention is not limited to the above two types, and includes other messages that can carry LSP information and are transmitted on the control channel.

The method for notifying the fault LSP information of the present invention is further described in detail below by taking the extended APS packet as an example.

The structure of the extended APS packet of the present invention is as shown in FIG. 4, wherein the Message length field indicates the length of the extended APS packet, and the TLV Offset field indicates that the first LSP TLV packet in the extended APS packet is in the extended APS packet. If the TLV Offset is 0, it indicates that there is no LSP TLV packet in the extended APS packet. If the TLV Offset is not 0, it indicates that the extended APS packet exists. LSP TLV packet.

It should be noted that the method for notifying the faulty LSP information of the present invention is applicable not only to the MPLS ring network but also to other ring networks such as a transported MPLS (T-MPLS, Transport-MPLS) network.

The following takes the MPLS ring network as an example. The method for advertising fault LSP information based on APS packet extension is shown in Figure 5. The main steps are as follows:

Steps 501 to 502, the node on the MPLS ring network detects the fault of the local link through the link detection mechanism, and determines whether the local link is faulty according to the detection result. If yes, step 503 is performed; otherwise, no processing is performed.

Step 503: The node that detects the link failure generates an extended APS packet, and the extended APS is The packet is sent to other nodes on the MPLS ring network through the APS control channel.

The node encapsulates the LSP information affected by the fault into the LSP TLV packet in the TLV format, and then encapsulates the LSP TLV packet into the extended APS packet generated by the LSP.

Step 504 505: The other node on the MPLS ring network receives the extended APS packet, and determines whether the LSP TLV packet exists in the extended APS packet according to the TLV Offset field in the extended APS packet. If the determination exists, step 506 is performed. Otherwise, no processing is done.

If the value of the TLV Offset field is 0, it is determined that there is no LSP TLV packet in the received extended APS packet. If the value of the TLV Offset field is not 0, it is determined that there is an LSP TLV packet in the received extended APS packet.

Step 506 507: Analyze and process the LSP TLV packet in the APS packet, and determine whether the fault affects the service related to the node itself. If yes, go to step 508; otherwise, do not process.

The detailed analysis is as follows: The node that receives the extended APS packet compares the LSP ID information in the LSP TLV packet with the LSP ID information of the service related to the node that receives the extended APS packet, if the same LSP ID information exists. Then, it is determined that the fault has an impact on the service related to the node itself; otherwise, it is determined that the fault has no impact on the service related to the node itself.

Step 508: Perform protection switching on the path of the affected service.

Specifically, the affected transmitting and receiving services of the node are sent and received from the opposite direction (ie, the protection path) of their current working path.

Optionally, when the node detects the fault, the extended APS packet is generated by the faulty state, and the other node is notified to switch the affected service back to the path before the fault occurs. The format of the extended APS packet in the fault-removing state is still as shown in FIG. 4, except that the extended APS packet is identified in the APS DATA field as an extended APS packet to cancel the fault state; in addition, the extended APS packet in the fault state is eliminated. The node does not need to carry the LSP information. The node that receives the extended APS packet switches all its services to the path before the fault occurs. The method for advertising the fault LSP information shown in FIG. 5, if applied to the T-MPLS ring network, only needs to replace the MPLS ring network in the above process with the T-MPLS ring network.

The present invention further provides a device 10 for advertised fault LSP information, which is applied to a node on a network ring, and the device 10 includes: a message generating module 11 and a message sending module 12 And the message receiving processing module 13. The packet generation module 11 is configured to encapsulate the LSP information affected by the fault into an LSP TLV packet, and then encapsulate the LSP TLV packet into the status advertisement packet generated by the LSP. The message sending module 12 is configured to send the status advertisement message to other nodes on the ring network. The packet receiving and processing module 13 is configured to receive the status advertisement packet, determine whether the fault affects the related service according to the LSP information in the status advertisement packet, and perform a path on the affected service when determining the impact Protection switching.

The message receiving and processing module 13 is further configured to: determine, according to the TLV Offset field of the status advertisement message, whether the LSP TLV message exists in the status advertisement message, if not, the process does not process; if yes, the status advertisement report The LSP TLV packet in the text is analyzed. Specifically, the LSP ID information in the LSP TLV packet is compared with the LSP ID information of the service related to the node receiving the state advertisement packet. If the same LSP ID exists. The information determines that the fault affects the service related to the node; otherwise, it determines that the fault has no impact on the service related to the node.

Preferably, the message generating module 11 is further configured to: when the node detects the fault elimination, generate a status advertisement message that cancels the fault state; and correspondingly, the message sending module 12 is further configured to send the status advertisement message to Other nodes on the ring network notify other nodes to switch the affected services to the path before the failure occurs.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A method for advertised LSP information of a fault label switching path, the method comprising:

The method for claiming fault LSP information according to claim 1, wherein the method further comprises: detecting, by the node that is faulty, the LSP information affected by the fault is encapsulated into an LSP TLV packet in the form of a type length value TLV. Then, the LSP TLV packet is encapsulated into a status advertisement message generated by itself.

The method for claiming the fault LSP information according to claim 1, wherein the method further comprises: determining, by the node receiving the status advertisement message, the status according to the TLV offset Offset field of the status advertisement message Whether the LSP TLV packet exists in the advertisement packet. If the LSP TLV packet is not present, the LSP TLV packet in the status advertisement packet is analyzed.

The method for notifying the fault LSP information according to claim 3, wherein the analyzing the LSP TLV text is: receiving the LSP ID information in the LSP TLV text and receiving the status advertisement message The LSP ID information of the related service of the node is compared. If the same LSP ID information exists, it is determined that the fault has an impact on its related service; otherwise, it is determined that the fault has no impact on its related service.

The method for claiming the faulty LSP information according to claim 1, wherein the method further comprises: when the fault is removed, detecting that the faulty node sends a status notification message to cancel the fault state, notifying the other The node switches the affected service to the fault. The path before.

The method of claiming the faulty LSP information according to any one of claims 1 to 5, wherein the status advertisement message is an extended automatic protection switching APS message or an operation management maintenance OAM message.

A device for advertised fault LSP information, the device comprising: a message generating module, configured to generate a status advertisement message for a node that detects a fault on the ring network; and a message receiving processing module, configured to receive a status The advertisement packet is determined according to the LSP information in the status advertisement packet, and determines whether the fault affects the related service, and performs protection switching on the affected service when the impact is determined.

The apparatus for advertising fault LSP information according to claim 7, wherein the packet generating module is further configured to encapsulate the LSP information affected by the fault into an LSP TLV packet in a TLV format, and then The LSP TLV packet is encapsulated into a status advertisement message generated by itself.

The apparatus for advertising fault LSP information according to claim 7, wherein the packet receiving processing module is further configured to: determine, according to the TLV Offset field of the status advertisement message, the status advertisement message Whether there is an LSP TLV packet. If it does not exist, do not do it.

The apparatus for advertising fault LSP information according to claim 9, wherein the packet receiving processing module is further configured to: receive LSP ID information in the LSP TLV packet, and receive a status advertisement message. The LSP ID information of the related service of the node is compared. If the same LSP ID information exists, it is determined that the fault has an impact on the service related to the node; otherwise, it is determined that the fault has no service related to the node. influences.

The apparatus for advertising fault LSP information according to claim 7, wherein the packet generating module is further configured to: when the node detects the fault elimination, generate a fault cancellation state. Status announcement message;

The apparatus for advertising faulty LSP information according to any one of claims 7 to 11, wherein the status advertisement message is an extended APS message or an OAM message.