WO2012079399A1

WO2012079399A1 - Multiplex section protection switching method for multiple element network system and inter network elements

Info

Publication number: WO2012079399A1
Application number: PCT/CN2011/079880
Authority: WO
Inventors: 薛亚军
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-12-15
Filing date: 2011-09-20
Publication date: 2012-06-21
Also published as: CN102075415A

Abstract

Disclosed is a multiplex section protection switching method for multiple element network system and inter network elements, comprising: a network element (B or C) configured with inter network elements multiplex section protection, and a network element (D) configured with pseudowire redundancy group, wherein the network elements configured with inter network element multiplex section protection packages the switching state into packets and sends them to the network element configured with pseudowire redundancy group protection during the switching of the work link or protect link. After the network element configured with pseudowire redundancy group protection has parsed the received packets, it extracts the switching state, and after making a decision based on the switching state it performs the switching of the pseudowire redundancy group protection. The application of the present invention allows the pseudowire side to receive the switching state of the multiplex section protection side while also accurately receiving the switching state, thus preventing situations where the switching time is too long or the switching results are erroneous.

Description

Multi-network element network and method for protecting multiplex section protection switching across network elements

Technical field

The present invention relates to the field of communications technologies, and in particular, to a multi-network element network and a multiplexing section protection switching method across network elements.

Background technique

Linear Multiplex Section Protection is defined in ITU-T (International Telecommunication Union Telecommunication Standardization Sector) G.841, which is a dedicated or shared protection mechanism for providing multiplex section layers. protection. Linear multiplex section protection is applied to point-to-point physical networks. A multiplex section protection is used to protect a certain number of working multiplex sections, but it cannot protect against node failures. Multiplex section protection works on single or double ended. In addition, when the multiplex section protection is in the idle state, it can also be used to open additional services without protection.

At the same time, in ITU-T G.8031, a mechanism for transmitting and receiving APS (Automatic Protection Switching) messages is described. When the protection status is changed, the first three messages are sent quickly, thereby ensuring even one or Two message losses can also be quickly and accurately reversed. Since the protection performance needs to meet the requirement of switching completion within 50ms, the APS reporting mechanism requires the first three messages to be sent in a 3.3ms period, and the subsequent text to be sent in a 5s period.

Because the multiplex section protection technology of three network elements and four network elements needs to be implemented in the existing networking, the multiplex section protection technology of the network element needs to be implemented, and MSP is separately configured on both sides of the protection of the cross-network element multiplex section.

(Multiplex Section Protection) and PW (Pseudowire) redundancy group protection. For example, in Figure 1, network element A is configured with multiplex section protection (MSP), and network element B and network element C are configured with multiplex section protection across network elements, where network element B and network element C are respectively configured to work. segment

(Main) and protection segment (standby), and the network element D is configured as a PW redundancy group protection. When the network element A or the network element B or the network element C is switched, the network element D is notified to perform PW side switching, thereby performing service It plays a protective role in the transmission process of the entire network.

The factors that cause the network element B or the network element C to generate the switching state include, but are not limited to, the following situations: When the working link or the protection link fails, the network element B or the network element C detects the failure. Then make a decision to generate a switching state;

When the network element B or the network element C receives an external command, it makes a decision to generate a switching state. When the network element B or the network element C receives the switching request of the network element A through the K1/K2 byte, the switching state is generated. Wherein, the K1 byte and the K2 byte are respectively described in ITU-T G.841, and the multiplex section protection (MSP) uses the automatic protection switching (APS) byte (MS1 K1 and K2) to send the request and Confirm the switching operation. It is a technical problem that needs to be solved for how to notify the network element D of the switching state generated in the above cases.

Summary of the invention

The technical problem to be solved by the present invention is to provide a multi-network element network and a multiplex section protection switching method of a cross-network element, which is used for solving the switching state of the multiplex section side and accurately notifying the protection side of the pseudo-line, so that The pseudowire side is consistent with the multiplex section side switching state.

In order to solve the above problem, the present invention provides a method for protecting a multiplex section protection switching across network elements, including:

When the working link or the protection link is switched, the network element configured with the protection of the multiplex section of the network element encapsulates the switching state into a packet and sends the packet to the network element configured with the protection of the pseudowire redundancy group.

The network element configured with the protection of the pseudowire redundancy group extracts the received message after parsing the received packet, and performs the switching of the protection side of the pseudowire redundancy group after the decision according to the switching state.

The network element configured with the protection of the multiplex section is encapsulated into a packet, and the packet is encapsulated into an automatic protection switching format.

When the network element configured with the cross-network element multiplex section protection sends a packet to the network element configured with the pseudowire redundancy group protection, the automatic protection switching reporting mechanism is used to send the first three reports in a 3.3 ms cycle. Text, and then send the text in a 5s cycle.

The network element that is configured to be protected by the multiplex section of the network element is a primary device network element or a standby device network element that is protected by the multiplex section of the network element.

The network element configured with the cross-network element multiplex section protection is configured to firstly search for a pseudo-line corresponding to the service of the switching protection, and send the packet to the configured pseudo-line redundancy group by using the found service corresponding pseudo-line. Protected network elements.

The packet encapsulated according to the switching state includes a request status field for indicating a switching status, and the request status field is an active status or a non-working status.

The present invention further provides a multi-network element network, including: a network element configured with a cross-network element multiplex section protection, and a network element configured with a pseudo-line redundancy group protection, where:

When a working element or a protection link is switched, the network element configured with the cross-network element multiplex section is encapsulated into a packet and sent to the network element configured with the pseudowire redundancy group protection.

The network element configured with the cross-network element multiplex section protection encapsulates the switching state into a message, and encapsulates the switching state into an automatic protection switching format packet; When the NEs configured with the pseudowire redundancy group are configured to send packets, the automatic protection switching mechanism is used to send the first three packets in a 3.3 ms period, and then send the packets in a period of 5 s.

The network element configured with the cross-network element multiplex section protection is configured to firstly search for a pseudo-line corresponding to the service of the switching protection, and send the packet to the configured pseudo-line redundancy group by using the found service corresponding pseudo-line. Protected network elements. The network element that is configured to be protected by the multiplex section of the network element is a primary device network element or a standby device network element that is protected by the multiplex section of the network element.

The present invention further provides a network element, which is configured with a cross-network element multiplex section protection, where the network element includes a package module and a sending module, where

The encapsulating module is configured to: when the working link or the protection link is switched, the switching state is encapsulated into a packet;

The sending module is configured to: send the packet encapsulated by the encapsulating module to a network element configured with a pseudowire redundancy group protection.

Preferably, in the network element,

The encapsulating module is configured to: encapsulate the switching state into a packet with an automatic protection switching format; The sending module is configured to: when the network element that is configured with the pseudowire redundancy group protection is sent, use the automatic protection switching reporting mechanism to send the first three packets in a 3.3 ms period. Then send the text in a 5s cycle.

Preferably, in the network element,

The sending module is configured to: send the packet to the network element configured with the pseudowire redundancy group protection by using the pseudowire corresponding to the service to search for the pseudowire corresponding to the service of the reversed protection.

Preferably, the network element is a primary device network element or a standby device network element protected by a network element multiplex section. The present invention further provides another network element, configured with a pseudowire redundancy group protection, where the network element includes a parsing module and a decision module;

The parsing module is configured to: receive a packet sent by an NE that is configured to be protected by the multiplex section of the network element, and parse and extract the switching state;

The decision module is configured to: perform switching of the protection side of the pseudowire redundancy group after the decision according to the switching state.

The above technical solution can not only enable the PW side to receive the switching state of the protection side of the multiplex section of the network element, but also accurately receive the state, thereby preventing the switching time from being too long or the switching result being incorrect. Although the PW side needs to perform packet parsing, it uses the notification method of the standard protocol (for example, APS), and does not need to re-establish a new channel to transmit packets. The PW protection channel can be multiplexed, and the cross-network element multiplex section can be accurately multiplexed. The protection side switching state is notified to the PW side to meet the protection performance requirements. BRIEF abstract

1 is a schematic diagram of a multi-network element network of a three-network element network provided by an embodiment of the present invention; FIG. 2 is a schematic diagram of a multi-network element network of a four-network element network provided by an embodiment of the present invention; Schematic diagram of the packet format of the APS-PDUs of the example;

FIG. 4 is a specific flowchart of a multiplex section protection switching of a cross-network element according to an embodiment of the present invention. Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

For the problem that the generated switching state is advertised to the network element D configured with the protection of the pseudowire redundancy group in the case described in the prior art, the present embodiment uses the APS packet advertisement manner to The decision result of the protection of the multiplex section is notified to the network element D, and the network element D performs the switching operation on the PW redundancy group according to the result of the protection decision of the cross-network element multiplex section and other elements, thereby realizing the protection of the entire network, which can satisfy the whole Network switching performance requirements.

The multi-network element network of this embodiment includes: a network element configured with a cross-network element multiplex section protection, that is, a primary device network element B and a standby device network element C, and a network element D configured with a pseudowire redundancy group protection ,

The network element B or C configured with the cross-network element multiplex section protection encapsulates the switching state into a packet transmitted to the network element D configured with the pseudowire redundancy group protection when the working link or the protection link is switched.

The network element D configured with the protection of the pseudowire redundancy group extracts the received packet and extracts the switching state. After the decision is made according to the switching state, the switching of the protection side of the pseudowire redundancy group is performed.

The packet encapsulated according to the switching state is an APS-like packet. When the packet is sent, the APS signaling mechanism can be used to send the first three packets in a 3.3 ms period, and then send the packets in a 5s period. .

After receiving the text, the network element D configured with the protection of the pseudowire redundancy group first performs text parsing, and takes out the switching state of the multiplex section protection; and then, according to the switching state and the local protection state. And other factors make decisions, and switch on the pseudowire (PW) side according to the decision result.

The method for protecting a multiplex section protection switching of a cross-network element in this embodiment includes:

When the working link or the protection link is switched, the network element B or C configured with the cross-network element multiplex section protection encapsulates the switching state into a packet and sends it to the network element D configured with the pseudowire redundancy group protection;

NE B or C encapsulates the switching state into packets, and encapsulates the switching state into automatic protection switching. APS formatted message.

When the network element B or C sends a packet to the network element D configured with the pseudowire redundancy group protection, it uses the automatic protection switching APS transmission mechanism to send the first three "3⁄4 texts" in a 3.3 ms period, and then The packet is sent in a 5s period.

The above technical solution can not only enable the PW side to receive the switching state of the protection side of the multiplex section of the network element, but also accurately receive the state, thereby preventing the switching time from being too long or the switching result being incorrect.

In a specific implementation, after the switching state is generated on the multiplex section of the network element, the network element B or C configured with the multiplex section protection is configured to encapsulate the generated switching state into an APS-PDU, and the service search is implemented by using the protection. The pseudowire PW corresponding to the service uses the APS packet sending mechanism to send a packet to the PW in the found PW, and sends the packet to the PW side network element D. If the network element D configured with the PW redundancy group protection is received, The packet carrying the switching state is parsed, and the packet is parsed according to the extracted switching state and the PW side state, and the switching is performed on the PW side.

It can be seen that, by using the packet advertisement scheme of the embodiment of the present invention, although the PW side needs to perform packet parsing, it uses a notification method of a standard protocol (for example, APS), and does not need to re-establish a new channel to transmit a message, which can be repeated. By using the PW protection channel, the PW side of the protection side of the multiplex section of the multiplex unit can be accurately notified to meet the protection performance requirements.

As shown in FIG. 1, a multi-network element system for a multiplex section protection switching scheme for a cross-network element according to an embodiment of the present invention is provided, including a network L A, B, C, and D, wherein:

The network element A is a network element configured with multiplex section protection (MSP);

The network element B is configured as a primary device network element protected by a multiplex section of the network element;

The network element C is a standby device network element configured to be protected across the network element multiplex section;

The network element D is a network element configured with a pseudowire redundancy group protection;

A working link is established from the network element A to the network element B, and a protection link is established from the network element A to the network element C. The pseudowire PW1 is set as the working path from the network element D to the network element B, and the network element D is connected to the network element. C establishes a pseudowire PW2 as a protection path. The PW redundancy protection group configured by NE D associates the working path and the protection path.

Assume that the working link fails when the network of the entire multi-network element is working normally. After the fault occurs, the network element C can receive the working link alarm of the network element B, and then make a decision; the network element C notifies the network element A of the switching state obtained by the K1/k2 byte, and the network element A performs the switching; The network element C encapsulates the switching state according to the APS packet format, and uses the APS signaling mechanism to send packets to the network element D through the protection path pseudowire PW2. The three consecutive 3.3ms fast packets are sent continuously, and then 5s is used. Periodically send the text.

After receiving the packet carrying the switching status, the network element D performs the unpacking process, analyzes the current multiplex section protection (MSP) switching status, and then switches the PW side according to the switching status to protect the service. In this way, the consistency of the switching action of the MSP and the PW can be ensured, and the real-time and reliability can be ensured.

In the multi-network element system shown in Figure 2, one network element E is added, and network element A and network element E are respectively configured to protect the multiplex section of the network element. The configurations of network elements B, C, and D are the same as those in Figure 1. For a multiplex section protection switching scheme of a cross-network element, refer to the description of the multi-network element system of FIG. 1 , and details are not described herein again.

As shown in FIG. 4, a schematic flowchart of a specific implementation of a multiplex section protection switching of a network element according to an embodiment of the present invention is provided, which includes the following steps:

Step 401: The network element (B or C) configured with the cross-network element multiplex section is configured to make a decision according to the link state, the external command, and the peer switching request, and generate a switching state.

Step 402: The network element in step 401 encapsulates the switching state into an APS-PDIL according to the encapsulation format of the APS packet, where the encapsulation format is as shown in FIG.

The Req State (Reuest State) can be 1 to indicate that the request is working, or 2 to indicate that the request is inactive.

Step 403: The network element in step 401 searches for the corresponding pseudowire PW according to the service that is protected. Step 404, the network element in step 401 uses the APS packet sending mechanism to search for the pseudowire PW in step 403. Message

Step 405: If the PW side network element receives the packet from the corresponding pseudowire PW found in step 403, performs parsing processing, and takes out the switching state.

Step 406: The PW side network element in step 405 performs a switching decision according to the switching state obtained by performing the parsing in step 405 and the local state on the PW side.

Step 407: The PW side network element in step 405 is in PW according to the result of the switching decision in step 406. The side performs handover, and the corresponding service in step 403 is protected.

In the end, the PW side is notified of the protection status of the protection side of the multiplex section of the multiplex unit. The MSP and PW side protection are consistent for the corresponding services, thus meeting the protection performance requirements.

The embodiment further provides a network element, which is configured with a cross-network element multiplex section protection, where the network element includes a package module and a sending module, where

Preferably, in the network element,

The encapsulating module is configured to: encapsulate the switching state into a message that automatically switches the switching format;

The sending module is configured to: when the network element that is configured with the pseudowire redundancy group protection is sent, use the automatic protection switching reporting mechanism to send the first three packets in a 3.3 ms period. Then send the text in a 5s cycle.

Preferably, in the network element,

Preferably, the network element is a primary device network element or a standby device network element protected by a network element multiplex section. The embodiment further provides another network element, configured with a pseudowire redundancy group protection, where the network element includes a parsing module and a decision module;

The above description is only an embodiment of the present invention, and is not intended to limit the present invention. The person skilled in the art can make various changes and modifications to the embodiments of the present invention. Any modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the appended claims.

Industrial applicability

The foregoing technical solution provides a method for multiplexing and protecting a multiplex section of a multi-network element network and a cross-network element, which is used for solving the problem of the switching state of the multiplex section and timely and accurately notifying the protection side of the pseudo-line, so that the pseudo-line side and the multiplexing side are used. The segment side switching status is consistent. The above technical solution can not only enable the PW side to receive the switching state of the protection side of the multiplex section of the network element, but also accurately receive the state, thereby preventing the switching time from being too long or the switching result being incorrect. Although the PW side needs to perform packet parsing, it uses the notification method of the standard protocol (for example, APS), and does not need to re-establish a new channel to transmit packets. The PW protection channel can be multiplexed, and the cross-network element multiplex section can be accurately multiplexed. The protection side switching state is notified to the PW side to meet the protection performance requirements.

Claims

Claim

A method for protecting and switching a multiplex section of a network element, comprising:

2. The method of claim 1 wherein

The step of encapsulating the switching state into a packet in the step of encapsulating the switching state into a packet is performed in the step of encapsulating the switching state into an automatic protection switching format.

3. The method according to claim 1 or 2, wherein

When the network element configured with the cross-network element multiplex section protection is configured to send the packet to the network element configured with the pseudo-line redundancy group protection, the network element configured with the cross-network element multiplex section protection is switched by using automatic protection. The reporting mechanism first sends the first 3 messages in a 3.3ms cycle, and then sends the message in a 5s cycle.

4. The method according to claim 3, wherein the network element configured to be protected by the multiplex section of the network element is a primary device network element or a standby device network element protected by the multiplex section of the network element.

5. The method of claim 3, wherein

In the step of transmitting the foregoing packet to the network element configured with the protection of the pseudowire redundancy group, the network element configured with the cross-network element multiplex section protection configures the network protected by the multiplex section of the network element The element is sent to the network element configured with the pseudowire redundancy group protection by using the pseudowire corresponding to the service that is switched and protected.

6. The method according to claim 1 or 2, wherein

The packet encapsulated by the switching state includes a request status field for indicating the switching status, and the request status field is an active status or a non-operation status.

A multi-network element network, comprising: a network element configured with a cross-network element multiplex section protection, and a network element configured with a pseudo-line redundancy group protection, where:

The network element configured with the cross-network element multiplex section protection is configured to: when the working link or the protection link is switched, the switching state is encapsulated into a packet and sent to the network element configured with the pseudowire redundancy group protection. ; The network element configured with the protection of the pseudowire redundancy group is configured to: after parsing the received packet, extract the switching state, and perform the switching of the protection side of the pseudowire redundancy group according to the switching state decision.

8. The multi-network element network of claim 7, wherein:

The network element configured with the cross-network element multiplex section protection is configured to: encapsulate the switching state into a packet that automatically protects the switching format;

The network element configured with the cross-network element multiplex section protection is configured to: when the packet is sent to the network element configured with the pseudowire redundancy group protection, the automatic protection switching reporting mechanism is used, first, 3.3 ms. The cycle sends the first 3 messages, and then sends the message in a 5s cycle.

9. The multiple network element network of claim 7, wherein:

The network element configured with the cross-network element multiplex section protection is configured to: send the packet to the configuration by using the pseudo-line corresponding to the searched service to find the pseudo-line corresponding to the service that is switched and protected. A network element protected by a pseudowire redundancy group.

10. The multi-network element network of claim 7 or 8 or 9, wherein:

A network element configured with a cross-network element multiplex section protection, where the network element includes a package module and a sending module, where

12. The network element according to claim 11, wherein

13. The network element according to claim 11, wherein

The network element according to claim 11, which is a primary device network element or a standby device network element protected by a network element multiplex section.

A network element configured with a pseudowire redundancy group protection, where the network element includes a parsing module and a decision module;