CN105656776B

CN105656776B - Pseudo wire dual-homing protection switching system, method and device

Info

Publication number: CN105656776B
Application number: CN201410715264.5A
Authority: CN
Inventors: 刘小飞; 席媛媛
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2014-12-01
Filing date: 2014-12-01
Publication date: 2020-03-27
Anticipated expiration: 2034-12-01
Also published as: WO2016086548A1; CN105656776A

Abstract

The invention discloses a pseudo wire dual-homing protection switching system, which comprises: the system comprises a main node, a standby node, a network side source node and a user side source node; a working PW is arranged between the main node and the network side source node, a protection PW is arranged between the standby node and the network side source node, a working AC is arranged between the main node and the user side source node, and a protection AC is arranged between the standby node and the user side source node; a first DNI PW and a second DNI PW are arranged between the main node and the standby node; the first DNI PW is used for protecting a working AC on the main node and carrying the flow from a source node on the network side; the system is also used for protecting and protecting the PW on the standby node and bearing the flow from the source node at the user side; the second DNI PW is used for protecting the working PW on the main node and bearing the flow from the source node at the user side; and the method is also used for protecting the protection AC on the standby node and carrying the traffic from the source node on the network side. The invention also discloses a pseudo wire dual-homing protection switching method and a pseudo wire dual-homing protection switching device.

Description

Pseudo wire dual-homing protection switching system, method and device

Technical Field

The invention relates to the technical field of Multi-Protocol Label Switching (MPLS) communication, in particular to a pseudo wire dual-homing protection Switching system, method and device.

Background

In an MPLS communication network, a Dual Node interconnection pseudowire (DNI PW) is mainly applied to a pseudowire Dual homing protection scenario, and the main principle thereof is as follows: a single-point protection is formed between the dual-homing devices, and a typical DNI PW dual-homing protection scenario is shown in FIG. 1, wherein PE2 and PE3 are dual-homing nodes, PE2 is a main node, PE3 is a standby node, and PE2 and PE3 are both realized by convergence layer devices; the PE1 is a network side source node and is realized by access layer equipment; PE4 is a user side source node and is realized by core layer equipment; a DNI PW is arranged between the dual-homing nodes PE2 and PE3, and its basic structure and functions of each part are as follows:

on the Network-Network Interface (NNI) side, PW protection groups are provided between PE1 and PE2, and between PE1 and PE3, and include: a working PW between PE1 and PE2, and a protection PW between PE1 and PE 3;

the User-network Interface (UNI) side supports the Protection mode of cross-Chassis Automatic Protection switching (MC-APS).

The DNI PW is used for forwarding service traffic between the dual-homed-node PE2 and the PE3, and the PE2 and the PE3 realize single-point service forwarding in a dual-node interconnection mode.

However, in the actual networking scheme of pseudowire dual-homing protection, the DNI PW needs to control both the switching of NNI-side traffic and UNI-side traffic, and it is usually difficult to ensure that no packet loss occurs during protection switching in a DNI scenario, so that it is difficult to achieve the standard of 50ms carrier-class protection switching.

The following lists several scenarios in which packet loss occurs:

scene 1: when the APS at the UNI side detects the link failure and performs fast protection switching, for the peer-to-peer device node PE3, it is impossible to timely sense that the working AC has a failure and to timely perform switching for the working AC failure, and therefore it is difficult to ensure fast switching, which results in packet loss and current break.

Taking fig. 1 as an example, when a working AC on a UNI side link fails, MC-APS protection switching of PE3 needs to take a long time to switch to a protection AC link through protocol packet interaction, resulting in packet loss of traffic from an NNI side;

scene 2: when the APS at the NNI side detects the link failure for fast protection switching, for PE3, it is impossible to sense the working PW failure in time and to perform switching for the working PW failure in time, and it is also difficult to ensure fast switching, which results in packet loss and cutoff.

Taking fig. 1 as an example, when a working PW on an NNI side link fails, MC-PW protection switching of PE3 needs to take a long time to switch to a protection PW link through protocol packet interaction, resulting in a traffic packet loss from the UNI side;

scene 3: when the main node is restarted after power failure, the standby node needs to control the protection switching of the NNI side flow and the UNI side flow at the same time, and packet loss and flow break caused by quick switching are difficult to guarantee.

Taking fig. 1 as an example, when the primary node fails, MC-APS protection switching of the standby node needs to take a long time to switch to the protection AC link through protocol packet interaction, resulting in traffic packet loss from the NNI side; MC-PW protection switching needs to take a long time to switch to a protection PW link through protocol message interaction, which causes traffic packet loss from a UNI side.

Disclosure of Invention

In order to solve the existing technical problem, embodiments of the present invention are expected to provide a pseudowire dual-homing protection switching system, method, and apparatus.

The embodiment of the invention provides a pseudo wire dual-homing protection switching system, which comprises: the system comprises a main node, a standby node, a network side source node and a user side source node; a working Pseudo Wire (PW) is arranged between the main node and a network side source node, a protection PW is arranged between the standby node and the network side source node, a working aggregation link (AC) is arranged between the main node and a user side source node, and a protection AC is arranged between the standby node and the user side source node; the method is characterized in that a first dual-node interconnection pseudowire DNI PW and a second DNI PW are arranged between a main node and a standby node; wherein,

the first DNI PW is used for protecting a working AC on the main node and carrying traffic from a source node on a network side; the system is also used for protecting and protecting the PW on the standby node and bearing the flow from the source node at the user side;

the second DNI PW is used for protecting the working PW on the main node and bearing the flow from the source node at the user side; and the method is also used for protecting the protection AC on the standby node and carrying the traffic from the source node on the network side.

In the above scheme, the primary node is configured to forward traffic from the first DNI PW to a network-side source node according to a working state of the working PW, and is further configured to forward traffic from the second DNI PW to a user-side source node through the working AC;

and the standby node is used for forwarding the traffic from the first DNI PW to the user side source node through the protection AC, and is also used for sending the traffic from the second DNI PW to the network side source node through the protection PW.

In the above scheme, the primary node is configured to forward traffic from the first DNI PW to a network source node through the working PW when the working PW has no failure; or,

and the method is used for quickly switching the traffic received on the first DNI PW to the second DNI PW and sending the traffic to the standby node when the working PW fails, and forwarding the traffic to the source node on the network side through the standby node.

Further, the system is also configured with a pseudo wire automatic protection switching (PW APS) and a cross-chassis pseudo wire automatic protection switching (MC-PW APS) for network side dual homing protection, and link aggregation/linear multiplexing segment protection (LAG/MSP) and cross-chassis link aggregation/linear multiplexing segment protection (MC-LAG/MSP) for customer side link protection.

In the above solution, the PW APS is configured to implement switching of traffic on a source node on a network side from a working PW to a protection PW when the working PW fails, and the MC-PW APS is simultaneously configured to implement switching from a primary node to a standby node when the working PW fails; the LAG/MSP is used for switching the working state of a source node at a user side to receive and send traffic through a protection AC when the working AC fails, and the MC-PW APS is simultaneously used for realizing the switching from the active node to the standby node when the working AC fails.

In the above scheme, in the process of sending traffic from a network side source node to a user side source node via a working PW under a normal system condition, after the traffic reaches a primary node, the traffic is sent to the user side source node via a working AC, and is sent to the user side source node via a first DNI PW and a protection AC; the user side source node selects one of the working AC and the protection AC according to the current working state to receive the flow;

when traffic is simultaneously sent to a network side source node from a user side source node through a working AC and a protection AC, a primary node receives the traffic sent by the working AC, a standby node sends the traffic sent by the protection AC to the primary node through a first DNI PW, and the primary node selectively receives the traffic sent by the working AC and blocks the traffic sent by the first DNI PW.

The embodiment of the invention provides a pseudo wire dual-homing protection switching method.A source node at a network side sends flow to equipment at a user side through a working Pseudo Wire (PW) or a protection PW, and the equipment at the user side respectively sends the flow to the equipment at the network side through a working aggregation link (AC) and a protection AC; the method further comprises the following steps:

when a source node at a network side sends flow to a source node at a user side, a main node protects a working AC through a first double-node interconnection pseudo wire DNI PW and bears the flow from the source node at the network side; the standby node protects the protection AC through a second DNI PW and bears the flow from the source node at the network side;

when a user side source node sends flow to a network side source node, a main node protects a working PW through a second DNI PW and bears the flow from the user side source node; and the standby node protects the PW through the first DNI PW and bears the traffic from the source node at the user side.

In the above scheme, the protecting, by the active node, the working AC through the first DNI PW includes: the primary node sends the flow to a standby node through a first DNI PW;

the method for protecting the working PW by the main node through the second DNI PW comprises the following steps: the primary node sends the flow to a standby node through a second DNI PW;

the standby node protects the AC through a second DNI PW, comprising: the standby node sends the flow to the main node through a second DNI PW;

the standby node protects the PW through the first DNI PW, and the method comprises the following steps: and the standby node sends the flow to the main node through the first DNI PW.

In the above scheme, when the primary node sends the traffic to the standby node through the first DNI PW, the standby node sends the traffic from the first DNI PW to the network side source node through the protection PW;

when the primary node sends the traffic to the standby node through the second DNI PW, the standby node sends the traffic from the second DNI PW to a network side source node through a protection PW;

when the standby node sends the traffic to the main node through the second DNI PW, the main node forwards the traffic from the second DNI PW to the source node at the user side through the working AC;

and when the standby node sends the flow to the main node through the first DNI PW, the main node forwards the flow to a network side source node according to the working state of the working PW.

In the above solution, the forwarding, by the master node, the traffic to the network side source node according to the working state of the working PW includes:

when the working PW has no fault, the main node forwards the flow from the first DNI PW to a network side source node through the working PW;

when the working PW fails, the active node quickly switches the traffic received on the first DNI PW to the second DNI PW to be sent to the standby node, and forwards the traffic to the source node on the network side through the standby node.

The embodiment of the invention provides a pseudo wire dual-homing protection switching method, which comprises the following steps:

when a source node at a network side sends flow to a source node at a user side, a main node protects a working aggregation link AC through a first double-node interconnection pseudo wire DNI PW and bears the flow from the source node at the network side;

when the user side source node sends the flow to the network side source node, the main node protects the working pseudo wire PW through the second DNI PW and bears the flow from the user side source node.

the method for protecting the working PW by the main node through the second DNI PW comprises the following steps: and the primary node sends the flow to the standby node through a second DNI PW.

Further, the method further comprises: when the primary node receives the traffic sent by the standby node through the second DNI PW, forwarding the traffic from the second DNI PW to the source node at the user side through the working AC; when receiving the traffic sent by the standby node through the first DNI PW, the primary node forwards the traffic to a network side source node according to the working state of the working PW.

The embodiment of the invention provides a pseudo wire dual-homing protection switching device, which is positioned on a main node and comprises: a first dual-node interconnect pseudowire DNI PW and a second DNI PW; wherein,

the first DNI PW is used for protecting the working aggregation link AC and bearing the traffic from the source node at the network side when the source node at the network side sends the traffic to the source node at the user side;

and the second DNI PW is used for protecting the working pseudo wire PW and bearing the flow from the source node of the user side when the source node of the user side sends the flow to the source node of the network side.

In the above scheme, the first DNI PW protects the working AC by:

receiving the flow sent by the main node and forwarding the flow to the standby node;

the second DNI PW protects the working PW by:

and receiving the flow sent by the main node and forwarding the flow to the standby node.

In the above scheme, the apparatus further comprises: the first traffic forwarding module is used for forwarding the traffic from the second DNI PW to the source node at the user side through the working AC when the primary node receives the traffic sent by the standby node through the second DNI PW; and the network node is also used for forwarding the traffic to a network side source node according to the working state of the working PW when the primary node receives the traffic sent by the standby node through the first DNI PW.

In the above solution, the apparatus further includes a determining module, configured to determine a current working state of the working PW, where the working state includes: failure and no failure;

the traffic forwarding module is used for forwarding the traffic from the first DNI PW to a network side source node through the working PW when the working PW has no fault;

and the traffic forwarding module is used for rapidly switching the traffic received on the first DNI PW to the second DNI PW and sending the traffic to the standby node when the working PW fails, and forwarding the traffic to the source node on the network side through the standby node.

when a network side source node sends flow to a user side source node, a standby node protects and protects an aggregation link AC through a second double-node interconnection pseudo wire DNI PW and bears the flow from the network side source node;

when a user side source node sends flow to a network side source node, a standby node protects a pseudo wire PW through a first DNI PW and bears the flow from the user side source node.

In the foregoing solution, the protecting the PW by the standby node through the first DNI PW includes: the standby node sends the flow to the main node through a first DNI PW;

the standby node protects the AC through a second DNI PW, comprising: and the standby node sends the flow to the main node through a second DNI PW.

In the above scheme, when receiving the traffic sent by the primary node through the first DNI PW, the standby node sends the traffic from the first DNI PW to the network side source node through the protection PW;

and when receiving the traffic sent by the main node through the second DNI PW, the standby node sends the traffic from the second DNI PW to a network side source node through the protection PW.

The embodiment of the invention provides a pseudo wire dual-homing protection switching device, which is positioned on a standby node and comprises: a third dual-node interconnect pseudowire DNI PW and a fourth DNI PW; wherein,

the third DNI PW is used for protecting the pseudo wire PW and carrying the traffic from the source node of the user side when the source node of the user side sends the traffic to the source node of the network side;

and the fourth DNI PW is used for protecting the aggregation link AC and carrying the traffic from the source node at the network side when the source node at the network side sends the traffic to the source node at the user side.

In the above scheme, the third DNI PW protects the protection PW in the following manner:

receiving the flow sent by the standby node and forwarding the flow to the main node;

the fourth DNI PW protects the protection AC by:

and receiving the flow sent by the standby node and forwarding the flow to the main node.

In the above scheme, the apparatus further comprises: the second traffic forwarding module is configured to send traffic from the third DNI PW to the network side source node through the protection PW when receiving traffic sent by the active node through the third DNI PW; and when receiving the traffic sent by the active node through the fourth DNI PW, the network node is further configured to send the traffic from the fourth DNI PW to the network side source node through the protection PW.

The embodiment of the invention provides a pseudo wire dual-homing protection switching system, a method and a device, wherein the pseudo wire dual-homing protection switching system comprises: the system comprises a main node, a standby node, a network side source node and a user side source node; wherein, a working pseudo wire PW is arranged between the main node and the network side source node; a protection PW is arranged between the standby node and the network side source node; a working aggregation link AC is arranged between the main node and the user side source node; a protection AC is arranged between the standby node and the user side source node; further, a first dual-node interconnection pseudowire DNI PW and a second DNI PW are arranged between the main node and the standby node; the first DNI PW is used for protecting a working AC on a primary node and carrying traffic from a source node on a network side; the system is also used for protecting and protecting the PW on the standby node and bearing the flow from the source node at the user side; the second DNI PW is used for protecting the working PW on the main node and bearing the flow from the source node at the user side; and the method is also used for protecting the protection AC on the standby node and carrying the traffic from the source node on the network side. Therefore, two DNI PWs are simultaneously arranged between the primary node and the standby node, one DNI PW forms a protection group with the working AC and the protection PW, the other DNIPW forms a protection group with the working PW and the protection AC, and cross protection is formed between the first DNI PW and the second DNI PW.

Drawings

FIG. 1 is a diagram of a DNI PW dual homing protection scenario in the prior art;

fig. 2 is a basic structure diagram of a pseudo wire dual homing protection switching system according to an embodiment of the present invention;

fig. 3 is an exemplary structure diagram of a pseudowire dual homing protection switching system according to an embodiment of the present invention;

fig. 4 is a first basic flowchart of a pseudowire dual homing protection switching method according to an embodiment of the present invention;

fig. 5 is a basic flowchart of a pseudowire dual homing protection switching method according to an embodiment of the present invention;

fig. 6 is a first structure diagram of a pseudo wire dual homing protection switching device according to an embodiment of the present invention;

fig. 7 is a basic flowchart of a pseudowire dual homing protection switching method according to an embodiment of the present invention;

fig. 8 is a second structure diagram of the pseudo wire dual homing protection switching device according to the embodiment of the present invention.

Detailed Description

The pseudo wire dual-homing protection switching system provided in the embodiment of the invention comprises: the system comprises a main node, a standby node, a network side source node and a user side source node; wherein, a working pseudo wire PW is arranged between the main node and the network side source node; a protection PW is arranged between the standby node and the network side source node; a working aggregation link AC is arranged between the main node and the user side source node; a protection AC is arranged between the standby node and the user side source node; further, a first dual-node interconnection pseudowire DNI PW and a second DNI PW are arranged between the main node and the standby node; the first DNIPW is used for protecting a working AC on a main node and carrying traffic from a source node on a network side; the system is also used for protecting and protecting the PW on the standby node and bearing the flow from the source node at the user side; the second DNI PW is used for protecting the working PW on the main node and bearing the flow from the source node at the user side; and the method is also used for protecting the protection AC on the standby node and carrying the traffic from the source node on the network side.

The invention is further described in detail below with reference to the figures and the specific embodiments.

Example one

An embodiment of the present invention provides a pseudo wire dual-homing protection switching system, as shown in fig. 2, the system includes: a main node 21, a standby node 22, a network side source node 23 and a user side source node 24; wherein,

a working PW is arranged between the main node 21 and the network side source node 23; a protection PW is arranged between the standby node 22 and the network side source node 23;

a working AC is arranged between the main node 21 and the user side source node 24; a protection AC is arranged between the standby node 22 and the user side source node 24;

based on the working mechanism of the user side source node 24, which is a double-sending and single-receiving mechanism, the user side traffic is sent to the network side through the working AC and the protection AC at the same time, and for the traffic from the network side, the user side source node 24 selects to receive the traffic of the working AC or the protection AC according to the working condition of a protection group formed by the current working AC and the protection AC, and simultaneously blocks the traffic of the other link;

based on the working mechanism of the network side source node 23 for single sending and single receiving, the network side source node 23 sends traffic to the user side source node 24 through the working PW or the protection PW, and receives traffic sent by the user side source node 24 through the working PW or the protection PW for sending traffic.

Further, a first DNI PW and a second DNI PW are disposed between the active node 21 and the standby node 22;

specifically, the first DNI PW is configured to protect a working AC on the active node 21, and carry traffic from the source node 23 on the network side; the method is also used for protecting and protecting the PW on the standby node 22 and carrying the flow from the source node 23 at the user side; the second DNI PW is configured to protect the working PW on the primary node 21, and carry traffic from the source node 24 on the user side; and also for protecting the protection AC at the standby node 22, carrying traffic from the source node 24 on the network side. Thus, a plurality of protection groups are formed in the pseudo wire dual-homing protection switching system; specifically, from a network side to a user side, firstly, a working PW and a protection PW are a pseudo-wire dual-homing protection group, a cross-chassis pseudo-wire dual-homing protection group is formed between a working AC and a first DNI PW, and a second DNI PW and a protection AC are formed into a cross-chassis pseudo-wire dual-homing protection group; from a user side to a network side, a working AC and a protection AC are a link protection group mutually, a working PW and a second DNI PW form a cross-rack pseudo wire dual-homing protection group, and a first DNI PW and a protection PW form a cross-rack pseudo wire dual-homing protection group.

Further, the active node 21 is configured to forward traffic from the first DNI PW to a network-side source node 23 according to the working state of the working PW, and is further configured to forward traffic from the second DNI PW to a user-side source node 24 through the working AC; the standby node 22 is configured to forward traffic coming from the first DNI PW to a user-side source node 24 through a protection AC, and further configured to send traffic coming from the second DNI PW to a network-side source node 23 through a protection PW. It can be seen that the forwarding direction of the traffic from the first DNIPW or the second DNI PW on the active node 21 or the standby node 22 is determined;

specifically, the working state of the working PW includes: failed and no failure.

Specifically, the active node 21 is configured to forward traffic from the first DNI PW to a source node on a network side through the working PW when the working PW has no fault; or,

It should be noted that, in a normal system, the working state of the source node 23 on the network side defaults to receiving traffic and sending traffic through the working PW, the working state of the source node 24 on the user side defaults to sending traffic through the working AC and the protection AC at the same time, and receives traffic through the working AC and blocks traffic from the protection AC;

therefore, as shown in fig. 2, in a normal system condition, when traffic is sent from the network-side source node 23 to the user-side source node 24 via the working PW, after the traffic reaches the primary node 21, the traffic is sent to the user-side source node 24 via the working AC, and is sent to the user-side source node 24 via the first DNI PW and the protection AC; the user side source node 24 receives the traffic sent by the working AC and blocks and protects the traffic sent by the AC;

when traffic is simultaneously sent from the user-side source node 24 to the network-side source node 23 via the working AC and the protection AC, at this time, since the working state of the network-side source node 23 is to receive the user-side traffic through the working PW, the active node 21 receives the traffic sent by the working AC, and at the same time, the standby node 22 sends the traffic sent by the protection AC to the active node 21 via the first DNI PW, and the active node 21 determines to receive the traffic sent by the working AC according to the current working state of the user-side source node 24 and blocks the traffic sent by the first DNI PW.

Further, the pseudo wire dual-homing protection switching system is configured with PW APS and MC-PW APS for network side dual-homing protection; specifically, the PW APS is configured to implement switching of traffic on a source node 23 on a network side from a working PW to a protection PW when the working PW fails, and the MC-PW APS is also configured to implement switching of the active node 21 to a standby node 22 when the working PW fails, that is, switching network side traffic originally sent by receiving the working PW through the active node 21 to network side traffic sent by receiving the protection PW through the standby node 22;

the pseudo wire dual-homing Protection switching system is configured with link aggregation/Linear multiplexing Section Protection (LAG/MSP) and cross-rack link aggregation/Linear multiplexing Section Protection (MC-LAG/LMSP) for user side link Protection; specifically, the LAG/MSP is configured to switch the working state of the source node 24 on the user side to receive and send traffic through the protection AC when the working AC fails, and the MC-PW APS is also configured to switch the active node 21 to the standby node 22 when the working AC fails, that is, switch the traffic on the user side originally sent by receiving the working AC through the active node 21 to the traffic on the user side sent by receiving the protection AC through the active node 21.

It can be seen that, in the above scheme, the first DNI PW and the second DNI PW directly form cross protection on the cross-chassis devices (the primary node 21 and the standby node 22) in the pseudowire dual-homing protection system, and respective division work is clear, and the forwarding direction of the traffic coming from the first DNI PW and the second DNI PW by the primary node 21 or the standby node 22 is also fixed;

therefore, when only the working AC fails, the user-side source node 24 quickly senses the failure and switches the current working state to receive and transmit traffic through the protection AC; the standby node 22 receives the traffic from the protection AC, selects to receive the traffic from the protection AC according to the working state of the working AC, and forwards the traffic to the primary node 21 through the first DNI PW, and the primary node 21 receives the traffic from the first DNIPW and directly sends the traffic to the network side source node 23 through the working PW according to the preset traffic forwarding direction; when the primary node 21 receives the traffic from the working PW from the network side to the user side, the primary node sends the traffic to the standby node 22 through the first DNI PW, and the standby node 22 directly sends the traffic sent from the first DNI PW to the source node 24 of the user side through the protection AC according to the preset traffic forwarding direction; as can be seen, when the working AC at the user side fails, the standby node 22 in the cross-chassis device has already realized fast and correct forwarding of traffic according to the preset forwarding direction before sensing the failure at the user side and performing the switching, so as to prevent packet loss;

when only the working PW fails, the network side source node 23 quickly senses the failure and sends network side traffic through the protection PW; when receiving the traffic from the protection PW, the standby node 22 sends the traffic to the user-side source node 24 through the second DNI PW and the protection AC respectively according to the working state of the current working PW, and when receiving the traffic from the second DNI PW, the main node 21 also forwards the traffic to the user-side source node 24 through the working AC according to a preset forwarding direction; from the user side to the network side, the user side source node 24 sends traffic to the network side source node 23 through the working AC and the protection AC, respectively, and after receiving the traffic sent by the working AC, the active node 21 senses the failure of the working PW, and thus sends the traffic to the standby node 22 through the second DNI PW, so that the standby node 22 receives the two traffic sent by the second DNI PW and the protection AC, and selects to receive the traffic sent by one link according to the working state of the current working AC, and blocks the other link; it can be seen that, when the working PW on the network side fails, according to the scheme provided in the embodiment of the present invention, the standby node 22 in the cross-chassis device already implements fast and correct forwarding of traffic according to the original forwarding direction before sensing the failure on the user side and performing the handover, thereby preventing packet loss;

when the working AC and the working PW fail at the same time, the user-side source node 24 sends the traffic to the standby node 22 through the protection AC, and the standby node 22 cannot timely sense that the working PW fails and perform switching, so that the traffic is still sent to the primary node 21 through the first DNI PW, and after the primary node 21 receives the traffic sent by the standby node 22, because the primary node 21 senses that the working PW fails, the primary node 21 quickly switches the traffic received on the first DNI PW to the second DNIPW and sends the traffic to the standby node 22; then, the standby node 22 directly forwards the traffic coming from the second DNI PW to the network side source node 23 according to a preset forwarding direction; therefore, through the above switching mechanism between the first DNI PW and the second DNI PW implemented on the active node 21, it can be ensured that when the working AC and the working PW fail at the same time, the traffic from the user side to the network side does not lose packets;

in addition, for the network side to the user side, the network side source node 23 sends the traffic to the standby node 22 through the protection PW, and the standby node 22 respectively forwards the traffic to the user side source node 24 through the protection AC and the second DNI PW according to the working state of the current working PW, so that it can be ensured that the traffic from the network side to the user side does not lose packets through this mechanism.

Fig. 3 is an exemplary structural diagram of a pseudowire dual-homing protection switching system according to an embodiment of the present invention; in fig. 3, PE1 is a network side source node, PE2 is a primary node, PE3 is a standby node, and PE4 is a user side source node; links 1, 2 are the input and output links, respectively, of PE 1; links 3 and 4 are respectively a working PW and a protection PW;

links

5 and 6 are two DNIPWs arranged between PE2 and PE3, wherein link 5 is DNI PW1, and link 6 is DNI PW 2; links 7, 8 are working AC and protection AC respectively; links 9, 10 are the output and input links on PE4, respectively;

the working principle of the pseudowire dual-homing protection switching system provided by the embodiment of the invention is described in detail below according to fig. 3.

Step S401: under the condition that all links work normally without faults, the pseudo wire protection of the PE1 and PE2 nodes works in a main mode, namely, the PE1 sends flow through a working PW (link 3), and the PE2 selects and receives the flow sent by the link 3; the MSP at PE4 node protects the master, i.e. PE4 chooses to receive traffic sent by the working AC (link 7).

At this time, there are two flows from the NNI side to the UNI side: (a) link 1 → link 3 → link 7 → link 9, i.e. traffic from link 1 goes through link 3, link 7 in turn to link 9, (b) link 1 → link 3 → link 5 → link 8 → link 9, the PE4 node working at the master option to receive traffic (a) according to the current MSP protection; there are also two flows from UNI side to NNI side: (a) link 10 → link 7 → link 3 → link 2, (b) link 10 → link 8 → link 5 → link 3 → link 2, the PE2 node selects and receives the traffic (a) according to the current working state, and blocks the traffic coming through link 5.

When the network side link 3 fails, go to step S402; when the user side link 7 fails, go to step S403; when the user side link 8 fails, the step S404 is executed; when the DNI master node PE2 loses power, the step S409 is switched;

step S402: under the condition that the NNI side link 3 has a fault, the working link fault is detected by the pseudo-wire protection of the PE1 and PE2 nodes and is quickly switched to the protection link, the UNI side does not sense the fault, and the MSP protection of the PE4 nodes is in the main state. At this time, there are two flows from the NNI side to the UNI side: (a) link 1 → link 4 → link 6 → link 7 → link 9, (b) link 1 → link 4 → link 8 → link 9, PE4 working at the primary election traffic (a) according to the current MSP protection; there are also two UNI side to NNI side traffic: (a) link 10 → link 7 → link 6 → link 4 → link 2, (b) link 10 → link 8 → link 4 → link 2, the PE2 node selects to receive traffic (b) according to the current operating state, and blocks traffic coming over link 6.

If the network side link 3 failure disappears, then go to step S401; if the user side link 7 fails, go to step S405; if the user side link 8 fails, go to step S407;

step S403: when the UNI side link 7 fails, the LMSP of the PE4 node detects that the working link fails and is quickly switched to the protection link, and the pseudo wire protection of the PE1 and PE2 nodes is mainly carried out. In this case, there are two flows from NNI side to UNI side: (a) link 1 → link 3 → link 7 (failure) → link 9, (b) link 1 → link 3 → link 5 → link 8 → link 9, PE4 working in alternative traffic reception (b) according to current LMSP protection, traffic coming over link 7 being blocked due to link failure; there are also two flows from UNI side to NNI side: (a) link 10 → link 7 (failure) → link 3 → link 2, (b) link 10 → link 8 → link 5 → link 3 → link 2, the PE2 node selects traffic (b) according to the current operating state, and traffic coming through link 7 is blocked due to the link failure.

If the network side link 7 failure disappears, then go to step S401; if the user side link 3 fails, step S406 is proceeded to.

Step S404: when the UNI side link 8 fails, the LMSP protection of the PE4 node works in the main state currently, the fault of the protection link is detected to still work in the main state, and the pseudo wire protection of the PE2 node works in the main state in PE 1. In this case, there are two flows from NNI side to UNI side: (a) link 1 → link 3 → link 7 → link 9, (b) link 1 → link 3 → link 5 → link 8 (failure) → link 9, PE4 working at the primary traffic (a) according to the current MSP protection, traffic coming over link 8 being blocked due to link failure; there is only one flow from UNI side to NNI side due to link 8 failure: link 10 → link 7 → link 3 → link 2.

If the network side link 8 failure disappears, then go to step S401; if the network side link 3 fails, go to step S408.

Step S405: if the NNI sideline 3 fails first, which is consistent with step S402, then the UNI sideline 7 fails, and the MSP protection of the PE4 node detects the working link failure and switches to the protection link quickly. In this case, there are two flows from NNI side to UNI side: (a) link 1 → link 4 → link 6 → link 7 (failure) → link 9, (b) link 1 → link 4 → link 8 → link 9, the PE4 node working at alternative traffic reception (b) according to current MSP protection, traffic coming over link 7 being blocked due to link failure; there are also two flows from UNI side to NNI side: (a) link 10 → link 7 (failure) → link 6 → link 4 → link 2, (b) link 10 → link 8 → link 4 → link 2, the PE2 node selects traffic (b) according to the current operating state, and traffic coming over link 7 is blocked due to the link failure.

If the user side link 7 failure disappears, step S402 is proceeded to.

Step S406: if the UNI side link 7 fails first, the step is consistent with the step S403, and then the NNI side link 3 fails, the PE1 and the PE2 node pseudowire protection detect that the working link fails and perform fast switch to the protection link. In this case, there are two flows from NNI side to UNI side: (a) link 1 → link 4 → link 6 → link 7 (failure) → link 9, (b) link 1 → link 4 → link 8 → link 9, the PE4 node working at alternative traffic reception (b) according to current MSP protection, traffic coming over link 7 being blocked due to link failure; UNI side to NNI side flow there is only one flow: link 10 → link 8 → link 4 → link 2.

If the network side link 3 failure disappears, step S403 is performed.

Step S407: if the NNI sideline 3 fails first, then the UNI sideline 8 fails, consistent with step S402. In this case, there are two flows from NNI side to UNI side: (a) link 1 → link 4 → link 6 → link 7 → link 9, (b) link 1 → link 4 → link 8 (failure) → link 9, the PE4 node working at the primary election traffic (a) according to the current MSP protection, traffic coming over link 8 being blocked due to link failure; UNI side to NNI side traffic there is only one traffic due to link 8 failure: link 10 → link 7 → link 6 → link 4 → link 2.

If the user side link 8 failure disappears, step S402 is proceeded to.

Step S408: if the UNI side link 8 fails first, consistent with step S404, then the NNI side link 3 fails, and the PE1, PE2 node pseudo-wire protection detects the working link failure and switches to the protection link quickly. In this case, there are two flows from NNI side to UNI side: (a) link 1 → link 4 → link 6 → link 7 → link 9, (b) link 1 → link 4 → link 8 (failure) → link 9, the PE4 node working at the primary election traffic (a) according to the current MSP protection, traffic coming over link 8 being blocked due to link failure; UNI side to NNI side traffic there is only one traffic due to link 8 failure: link 10 → link 7 → link 6 → link 4 → link 2.

If the network side link 3 failure disappears, go to step S404.

Step S409: a power down failure condition for the DNI master node PE 2. (1) PE1 node PW pseudo wire protection detects the working link trouble and carries out fast switch to the protection PW link, PE3 node DNI PW pseudo wire protection detects the working link trouble and carries out fast switch to the protection PW link, PE4 node LMSP protection detects the working link trouble and carries out fast switch to the protection AC link, and the condition is forwarded to the flow this moment, and NNI side to UNI side flow has two flows: (a) link 1 → link 4 → link 6 → link 7 (failure) → link 9, (b) link 1 → link 4 → link 8 → link 9, the PE4 node working at alternative traffic reception (b) according to current MSP protection, traffic coming over link 7 being blocked due to link failure; there are also two flows from UNI side to NNI side: (a) link 10 → link 7 (failure) → link 6 → link 4 → link 2, (b) link 10 → link 8 → link 4 → link 2, the PE2 node selects traffic (b) according to the current operating state, and traffic coming over link 7 is blocked due to the link failure.

If the DNI master node PE2 has failed away and is powered up, then step S401 is passed.

Other cases are as follows: if the working AC and the protection AC on the UNI side fail simultaneously, or the working PW and the protection PW on the NNI side fail simultaneously, namely the link 3 and the link 4 fail simultaneously, or the link 7 and the link 8 fail simultaneously, the forwarding of the network traffic does not change. Since the flow forwarding of the faulty pseudo wire dual-rule protection backup link 4 on the NNI side is consistent with step S401, the description is not repeated here. If the link 5 or the link 6 fails, the cross DNI pseudo wire dual-homing protection networking scene is degraded into a common pseudo wire dual-homing protection networking scene, so that the analysis is not performed here.

The working principle of PW APS and LAG/MSP similar to MC-PW APS and MC-LAG/MSP according to the embodiment of the present invention will be described based on FIG. 3;

the PW APS is a network protection mechanism, and is mainly used for detecting a network side fault and switching services, and when a working PW fails, the services are switched to a protection PW, so as to protect services carried on the working PW. PW APS detects the states of working PW and protection PW through a PW Bidirectional Forwarding Detection (BFD) mechanism or an Operation Administration and Maintenance (OAM) detection mechanism, when PE equipment detects that the working PW fails, PE equipment at two ends interacts APS protocols, PW APS switching is executed, and services are switched to the protection PW to realize service protection. PW APS supports two networking applications: an intra-device protection group and an inter-device (MC-PW APS) protection group. Under normal condition, the service is transmitted on the working PW, when the working PW fails, APS protection switching occurs, and the service is transmitted on the protection PW.

As shown in fig. 3, in PE1, PE2, and PE3, the PW APS status detection switching process is as follows:

step S501: and starting OAM/BFD message detection on the working PW of the PE1 equipment configured with the pseudo wire protection group, and turning to step S502.

Step S302: and judging whether the working PW of the working link of the pseudo wire protection group has OAM/BFD detection alarm or not, if so, determining that the working PW has a fault, and then, turning to the step S303.

Step S503: on the PE1 device, the APS performs protocol calculation to determine whether the pseudowire protection group is switched, if yes, go to step S504.

Step S504: on the main PW of the working link of the pseudo wire protection group, an alarm is generated by OAM/BFD message detection link failure, the APS carries out protocol calculation to switch the pseudo wire protection group to the protection link protection PW, and then the step S505 is switched.

Step S505: and judging whether the OAM/BFD detection alarm on the main PW of the pseudo wire protection working link disappears, if so, turning to step S506.

Step S506: and sending an OAM/BFD detection message on the main PW of the pseudo wire protection working link, notifying that the link failure disappears, and turning to the step S507.

Step S507: and when the OAM/BFD message detection link fault alarm disappears on the pseudo wire protection group working link main PW, the APS calculates the pseudo wire protection and switches back to the working link main PW, and the step S502 is switched.

LAG refers to a technique of aggregating a plurality of ethernet ports into one logical port. The LACP protocol is used to dynamically control whether a physical port is added to an aggregation group. In the non-load sharing link aggregation group, each LAG group can be configured with two members to form a 1:1 protection mode, the service is transmitted only on a working port, and when the working port fails, the protection port can be quickly started so as to ensure that the service flow normally works. LMSP is linear multiplex section protection, mainly used to emulate the protection of narrowband service ports. The LMSP completes the switching protocol exchange through the overhead K1/K2 bytes of the multiplex section in the SDH frame. LAG/MSP is mainly used for user side fault detection and link switching.

As shown in fig. 3, the user side link failure at PE2, PE3, and PE4, the switching flow of the link status detection of LAG/LMSP or MC-LAG/LMSP is as follows:

step S601: and starting LAG/SDH message detection on a working link main AC (namely a working AC) of the LAG/LMSP port protection group configuration device, and turning to the step S602.

Step S602: and judging whether the LAG/LMSP protection working link main AC has a link detection alarm or not, and if so, turning to the step S603.

Step S603: and (4) detecting the link failure on the working link main AC, generating an alarm, switching the alarm to a protection link standby AC (protection AC), and turning to the step S604.

Step S604: and judging whether the alarm on the LAG/MSP port protection group main AC disappears, and if so, turning to the step S605.

Step S605: and the working link main AC notifies that the link failure disappears, and the step S606 is carried out.

Step S606: the link failure alarm on the working link main AC disappears, the LAG/LMSP port protection switches back to the working link main AC, and step S602 is performed.

Example two

The second embodiment of the present invention provides a pseudo wire dual homing protection switching method, as shown in fig. 4, the method includes the following steps:

step 401: a network side source node sends flow to user side equipment through a working pseudo wire PW or a protection PW, and the user side equipment respectively sends flow to the network side equipment through a working AC and a protection AC;

step 402: when a network side source node sends flow to a user side source node, a main node protects a working AC through a first DNI PW and bears the flow from the network side source node; the standby node protects the protection AC through a second DNI PW and bears the flow from the source node at the network side;

specifically, the protecting, by the active node, the working AC through the first DNI PW includes: the primary node sends the flow to a standby node through a first DNI PW;

Further, when the primary node sends the traffic to the standby node through the first DNI PW, the standby node sends the traffic from the first DNI PW to a network side source node through a protection PW;

and when the standby node sends the traffic to the active node through the second DNI PW, the active node forwards the traffic from the second DNI PW to the source node at the user side through the working AC.

Step 403: when a user side source node sends flow to a network side source node, a main node protects a working PW through a second DNI PW and bears the flow from the user side source node; the standby node protects the PW through the first DNI PW and bears the flow from the source node at the user side;

specifically, the step of protecting the working PW by the primary node through the second DNI PW includes: the primary node sends the flow to a standby node through a second DNI PW;

Further, when the primary node sends the traffic to the standby node through the second DNI PW, the standby node sends the traffic from the second DNI PW to a network side source node through a protection PW;

Specifically, the working state of the working PW includes: failure and no failure;

It can be understood by those skilled in the art that the above steps 401-403 are not ordered in actual use.

EXAMPLE III

An embodiment of the present invention provides a pseudowire dual homing protection switching method, as shown in fig. 5, the method includes:

step 501: when a network side source node sends flow to a user side source node, a main node protects a working AC through a first DNI PW and bears the flow from the network side source node;

step 502: and when the user side source node sends the flow to the network side source node, the main node protects the working PW through the second DNI PW and bears the flow from the user side source node.

Specifically, the step of protecting the working PW by the primary node through the second DNI PW includes: the primary node sends the flow to the standby node through a second DNI PW

Specifically, the forwarding, by the active node, the traffic to the source node on the network side according to the working state of the working PW includes:

It will be appreciated by those skilled in the art that the

above steps

501 and 502 are not prioritized in actual use.

Example four

A fourth embodiment of the present invention provides a pseudo wire dual-homing protection switching apparatus, located on a primary node, as shown in fig. 6, the apparatus includes: a first DNI PW61 and a second DNI PW 62; wherein,

the first DNI PW61 is used for protecting the working AC and carrying the traffic from the network side source node when the network side source node sends the traffic to the user side source node;

and the second DNI PW 62 is used for protecting the working PW and carrying the traffic from the user side source node when the user side source node sends the traffic to the network side source node.

Specifically, the first DNI PW61 protects the working AC by:

Specifically, the second DNI PW 62 protects the working PW by:

Further, the apparatus further comprises: a first traffic forwarding module 63, configured to forward, when the primary node receives traffic sent by the standby node through the second DNI PW, the traffic sent by the second DNI PW to the user-side source node through the working AC; and the network node is also used for forwarding the traffic to a network side source node according to the working state of the working PW when the primary node receives the traffic sent by the standby node through the first DNI PW.

Further, the apparatus further includes a determining module 64, configured to determine a current working state of the working PW, where the working state includes: failure and no failure;

the traffic forwarding module 63 is configured to forward traffic from the first DNI PW61 to a source node on a network side through a working PW when the working PW has no fault;

and the traffic forwarding module 63 is configured to, when the working PW fails, quickly switch traffic received on the first DNI PW61 to the second DNI PW 62, send the traffic to the standby node, and forward the traffic to the network-side source node through the standby node.

EXAMPLE five

An embodiment of the present invention provides a pseudowire dual homing protection switching method, as shown in fig. 7, the method includes:

step 701: when the source node at the network side sends the flow to the source node at the user side, the standby node protects the protection AC through the second DNI PW and bears the flow from the source node at the network side;

specifically, the protecting the AC by the standby node through the second DNI PW includes: and the standby node sends the flow to the main node through a second DNI PW.

Step 702: when a user side source node sends flow to a network side source node, a standby node protects a PW through a first DNI PW and bears the flow from the user side source node;

specifically, the protecting the PW by the standby node through the first DNI PW includes: and the standby node sends the flow to the main node through the first DNI PW.

Further, the method further comprises: when receiving the traffic sent by the main node through the first DNIPW, the standby node sends the traffic on the first DNI PW to a network side source node through the protection PW;

It can be understood by those skilled in the art that the

above steps

701 and 702 do not distinguish the order in actual use.

EXAMPLE six

An embodiment of the present invention provides a pseudo wire dual-homing protection switching apparatus, which is located on a standby node, and as shown in fig. 8, the apparatus includes: a third DNI PW 81 and a fourth DNI PW 82; wherein,

the third DNI PW 81 is configured to protect a protection PW and carry traffic from the user side source node when the user side source node sends traffic to the network side source node;

and the fourth DNI PW 82 is configured to protect the protection AC and carry traffic from the network side source node when the network side source node sends the traffic to the user side source node.

Specifically, the third DNI PW 81 protects the protection PW by:

the fourth DNI PW 82 protects the protection AC by:

Further, the apparatus further comprises: a second traffic forwarding module 83, configured to send, when receiving traffic sent by the active node through the first DNI PW, the traffic from the first DNI PW to a network-side source node through the protection PW; and when receiving the traffic sent by the active node through the second DNI PW, sending the traffic from the second DNI PW to the source node on the network side through the protection PW.

In a specific implementation process, the first traffic forwarding module 63 and the determining module 64 may be implemented by a Central Processing Unit (CPU), a microprocessor unit (MPU), a Digital Signal Processor (DSP), or a programmable logic array (FPGA) in the main node; the second traffic forwarding module 83 may be implemented by a CPU, an MPU, a DSP, or an FPGA in the standby node; the first DNI PW61, the second DNI PW 62, the third DNI PW 81, and the fourth DNI PW 82 described above may be implemented by communication links.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

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

Claims

1. A pseudowire dual-homing protection switching system, the system comprising: the system comprises a main node, a standby node, a network side source node and a user side source node; a working Pseudo Wire (PW) is arranged between the main node and a network side source node, a protection PW is arranged between the standby node and the network side source node, a working aggregation link (AC) is arranged between the main node and a user side source node, and a protection AC is arranged between the standby node and the user side source node; the method is characterized in that a first dual-node interconnection pseudowire DNI PW and a second DNI PW are arranged between a main node and a standby node; wherein,

the first dual-node interconnection pseudo wire DNI PW is used for protecting a working AC on a primary node and carrying flow from a source node on a network side; the system is also used for protecting and protecting the PW on the standby node and bearing the flow from the source node at the user side;

the second DNI PW is used for protecting the working PW on the main node and bearing the flow from the source node at the user side; and the protection AC is also used for protecting the standby node and carrying the traffic from the source node on the network side.

2. The system of claim 1,

the primary node is used for forwarding the traffic from the first DNI PW to a network side source node according to the working state of the working PW, and is also used for forwarding the traffic from the second DNI PW to a user side source node through a working AC;

3. The system according to claim 2, wherein the active node is configured to forward traffic from the first DNI PW to a source node on a network side through the working PW when the working PW has no failure; or,

4. The system of any one of claims 1 to 3, wherein the system is further configured with an automatic pseudo-wire protection switch (PW) APS and an automatic cross-chassis pseudo-wire protection switch (MC-PW) APS for network side dual homing protection, and link aggregation/linear multiplexed segment protection (LAG/MSP) and cross-chassis link aggregation/linear multiplexed segment protection (MC-LAG/MSP) for customer side link protection.

5. The system according to claim 4, wherein the PW APS is configured to implement switching of traffic on a source node on a network side from a working PW to a protection PW when the working PW fails, and the MC-PW APS is simultaneously configured to implement switching from an active node to a standby node when the working PW fails; the LAG/MSP is used for switching the working state of a source node at a user side to receive and send traffic through a protection AC when the working AC fails, and the MC-PW APS is simultaneously used for realizing the switching from the active node to the standby node when the working AC fails.

6. The system according to any one of claims 1 to 3, wherein in a normal system condition, in the process of sending traffic from a network side source node to a user side source node via a working PW, after the traffic reaches a primary node, the traffic is sent to the user side source node via a working AC, and is sent to the user side source node via a first DNI PW and a protection AC; the user side source node selects one of the working AC and the protection AC according to the current working state to receive the flow;

7. A pseudo wire dual-homing protection switching method, a network side source node sends flow to a user side device through a working pseudo wire PW or a protection PW, and the user side device sends flow to the network side device through a working aggregation link AC and a protection AC respectively; characterized in that the method further comprises:

8. The method of claim 7, wherein the active node protecting the working AC via a first DNIPW comprises: the primary node sends the flow to a standby node through a first DNI PW;

the method for protecting the working PW by the main node through the second DNI PW comprises the following steps: the main node sends the flow to the standby node through a second DNIPW;

the standby node protects the AC through a second DNI PW, comprising: the standby node sends the flow to the main node through a second DNIPW;

the standby node protects the PW through the first DNI PW, and the method comprises the following steps: and the standby node sends the flow to the main node through the first DNIPW.

9. The method according to claim 8, wherein when the active node sends the traffic to a standby node through a first DNI PW, the standby node sends the traffic coming from the first DNI PW to a network-side source node through a protection PW;

10. The method according to claim 9, wherein the forwarding, by the active node, the traffic to a source node on a network side according to the working state of the working PW includes:

11. A pseudo wire dual homing protection switching method is characterized by comprising the following steps:

12. The method of claim 11, wherein the active node protecting the working AC with the first DNI PW comprises: the primary node sends the flow to a standby node through a first DNI PW;

the method for protecting the working PW by the main node through the second DNI PW comprises the following steps: and the primary node sends the flow to the standby node through the second DNIPW.

13. The method of claim 12, further comprising:

when the primary node receives the traffic sent by the standby node through the second DNI PW, forwarding the traffic from the second DNI PW to the source node at the user side through the working AC;

when receiving the traffic sent by the standby node through the first DNI PW, the primary node forwards the traffic to a network side source node according to the working state of the working PW.

14. The method according to claim 13, wherein the forwarding, by the active node, the traffic to a source node on a network side according to the working state of the working PW includes:

15. A pseudo wire dual-homing protection switching device, located on a primary node, the device comprising: a first dual-node interconnect pseudowire DNI PW and a second DNI PW; wherein,

the first dual-node interconnection pseudowire DNI PW is used for protecting a working aggregation link AC and bearing the traffic from a network side source node when the network side source node sends the traffic to a user side source node;

16. The apparatus of claim 15, wherein the first DNI PW protects the working AC by:

the second DNI PW protects the working PW by:

17. The apparatus of claim 16, further comprising: the first traffic forwarding module is used for forwarding the traffic from the second DNI PW to the source node at the user side through the working AC when the primary node receives the traffic sent by the standby node through the second DNI PW; and the network node is also used for forwarding the traffic to a network side source node according to the working state of the working PW when the primary node receives the traffic sent by the standby node through the first DNI PW.

18. The apparatus according to claim 15, wherein the apparatus further comprises a determining module, configured to determine a current working state of the working PW, where the working state includes: failure and no failure;

19. A pseudo wire dual homing protection switching method is characterized by comprising the following steps:

20. The method of claim 19, wherein protecting the PW with the first DNI PW comprises: the standby node sends the flow to the main node through a first DNI PW;

the standby node protects the AC through a second DNI PW, comprising: and the standby node sends the flow to the main node through the second DNIPW.

21. The method of claim 20, wherein when receiving traffic sent by the active node through the first DNI PW, the standby node sends the traffic coming from the first DNI PW to a source node on a network side through a protection PW;

22. A pseudowire dual homing protection switching device located on a standby node, the device comprising: a third dual-node interconnect pseudowire DNI PW and a fourth DNI PW; wherein,

the third dual-node interconnection pseudo wire DNI PW is used for protecting a pseudo wire PW and carrying the flow from the user side source node when the user side source node sends the flow to the network side source node;

23. The apparatus of claim 22, wherein the third DNI PW protects the protection PW by:

the fourth DNI PW protects the protection AC by:

24. The apparatus of claim 23, further comprising: the second traffic forwarding module is configured to send traffic from the third DNI PW to the network side source node through the protection PW when receiving traffic sent by the active node through the third DNI PW; and when receiving the traffic sent by the active node through the fourth DNI PW, the network node is further configured to send the traffic from the fourth DNI PW to the network side source node through the protection PW.