CN105306330A - Network protection method and device, and primary convergence network element in network - Google Patents

Abstract

The invention discloses a network protection method, a device, and an aggregation main network element in the network. The network includes a first network layer, a second network layer, and a convergence layer between the first network layer and the second network layer ; When it is detected that the active link of one of the two network layers and the aggregated link between the active network element and the backup network element in the aggregation layer fail at the same time, trigger another event that the active link has not failed. Network elements in a network layer are switched from the active link in the network layer to the backup link, so as to realize the linkage protection of the networking and avoid interruption of service flow.

Description

Networking protection method, device, and aggregation main network element in networking

technical field

The present invention relates to the communication field, in particular to a network protection method and device, and a main convergence network element in the network.

Background technique

The current MPLS-TP (based on "Multi-Protocol Label Switching" connection-oriented packet switching network technology, Multi-ProtocolLabelSwitching-TransportProfile) carrying LTE (Long Term Evolution, Long Term Evolution) solution uses L2VPN (Layer Two Virtual Private Network, LayerTwoVirtualPrivateNetwork) + L3VPN ( Three-layer virtual private network (LayerThreeVirtualPrivateNetwork) networking, that is, the Line (linear) networking technology is still used at the network access layer, the Line service at the access layer is terminated at the aggregation layer, and the L2VPN to L3VPN is completed inside the aggregation node. Bridging, entering the L3VPN processing and forwarding to the network core layer. In terms of end-to-end network protection, for this kind of networking, MPLS-TP provides powerful and rich OAM alarm detection methods, supports multiple carrier-class protection methods, has mature carrier-class protection capabilities, and can provide 50ms protection switching capabilities . In the L2VPN network, it is implemented through the cooperation of MPLS-TP linear protection or ring network protection and pseudo-wire dual-homing protection. In the L3VPN network, it is implemented through VRRP (Virtual Router Redundancy Protocol), MPLS-TP linear protection or ring network and L3VPNFRR ( Fast rerouting, FastReRoute) is implemented together. However, the current above-mentioned protection scheme still has a defect. The defect is that the protection of the L2VPN network and the L3VPN network have not been linked, resulting in service flow interruption in the following two situations:

1. When the L3VPN FRR switchover caused by network link failure occurs on the L3VPN network, and the link between the active node and the backup node of the aggregation layer is also faulty; the service flow from the core layer to the access layer will be switched to the aggregation layer On the standby node, the other direction from the access layer to the core layer is still normal due to the normal working path of the L2VPN network, and there will be no pseudo-wire dual-homing switching, so the service flow from the access layer to the core layer is still on the L2VPN network. Walking on the working path, but in fact at this time the active node of the aggregation layer has been isolated from the L3VPN network, resulting in the interruption of the service flow from the access layer to the core layer;

2. When the pseudo-wire dual-homing protection switching caused by network link failure occurs in the L2VPN network, and the link between the active node and the backup node of the aggregation layer is also faulty; the service flow from the access layer to the core layer will be Switching to the standby node of the aggregation layer, the core layer goes to the other direction of the access layer, but because the working path of the L3VPN network is still normal, there will be no FRR switching, so the service flow from the core layer to the access layer is in the L3VPN network part It is still on the working path, but at this time, the main NE at the aggregation layer is already isolated from the L2VPN network, which also interrupts the service flow from the core layer to the access layer.

Contents of the invention

The main technical problem to be solved by the present invention is to provide a network protection method, a device and a convergent active network element in the network, so as to solve the problem of service flow interruption caused by the lack of linkage protection in the existing network.

In order to solve the above technical problems, the present invention provides a network protection method, the network includes a first network layer and a second network layer, the first network element and the second network element respectively located in the first network layer and the second network layer network elements, and the aggregated active network element and aggregated standby network element located at the convergence of the first network layer and the second network layer; the link connecting the first network element and the aggregated active network element is the active network element of the first network layer link; the link connecting the second network element and the aggregated active network element is the active link of the second network layer; the link connecting the first network element and the aggregated standby network element is the standby link of the first network layer The link connecting the second network element and the aggregation standby network element is a backup link of the second network layer; the link connecting the aggregation main network element and the aggregation backup network element is an aggregation link; the method includes :

Detect whether the active link of one of the two network layers and the aggregated link fail at the same time, if so, trigger the network element in the other network layer where the active link has not failed to The primary link in the layer is switched to the standby link.

In one embodiment of the invention, when the failure of the failed active link and/or aggregated link is eliminated, triggering the network element in another network layer where the active link has not failed to start from the network layer The backup link in the switch is switched back to the active link.

In an embodiment of the invention, detecting whether the active link of one of the two network layers and the aggregation link fails simultaneously includes:

Detect whether the status detection message sent by the network element in one of the network layers of the two network layers can only be received normally; if so, the active link in the other network layer and the aggregation link simultaneously malfunction.

In an embodiment of the invention, the triggering the network element in another network layer where the active link has not failed to switch from the active link in the network layer to the standby link includes:

Triggering the aggregation active network element to stop feeding back the status detection message to the network element in the network layer normally, so that the network element judges that the active link fails and switches to the backup link;

Or directly send an instruction to switch to the standby link to the network element in the network layer, so that the network element switches from the active link in the network layer to the standby link.

In an embodiment of the invention, the triggering the network element in another network layer where the active link has not failed to switch back to the active link from the standby link in the network layer includes:

Triggering the aggregation active network element to feed back a normal state detection message to the network element in the network layer again, so that the network element judges that the failure of the active link is eliminated and switches to the backup link;

Or directly send an instruction to switch to the active link to the network element in the network layer, so that the network element

The standby link in the network layer is switched to the active link.

In one embodiment of the invention, the first network layer is a three-layer virtual private network layer, and the first network element is a core layer network element; the second network layer is a two-layer virtual private network layer, so The second network element is an access layer network element.

In order to solve the above problems, the present invention also provides a network protection device. The network includes a first network layer and a second network layer, and the first network element and the second network element respectively located in the first network layer and the second network layer Two network elements, as well as the aggregation main network element and the aggregation standby network element located at the convergence of the first network layer and the second network layer; the link connecting the first network element and the aggregation main network element is the main network element of the first network layer link; the link connecting the second NE and the converged active NE is the active link of the second network layer; the link connecting the first NE and the converged standby NE is the standby link of the first network layer road; the link connecting the second network element and the aggregation standby network element is the backup link of the second network layer; the link connecting the aggregation main network element and the aggregation backup network element is the aggregation link; the device Including the fault detection module and the first link switching module:

The failure detection module is used to detect whether the active link of one of the two network layers and the aggregation link fail at the same time, and if so, notify the first link switching module;

The first link switching module is configured to trigger a network element in another network layer whose active link has not failed to switch from the active link in the network layer to the standby link according to the notification.

In one embodiment of the invention, it also includes a second link switching module, configured to trigger another active link that has not failed when the faulty active link and/or aggregation link is eliminated. A network element in a network layer is switched back to the active link from the standby link in the network layer.

In one embodiment of the invention, the fault detection module includes a message detection sub-module, which is used to detect whether the status detection sent by the network element in one of the two network layers can only be received normally. message; if yes, it is determined that the active link in another network layer and the aggregated link fail at the same time.

In an embodiment of the invention, the first link switching module includes a first triggering submodule, configured to trigger the convergence active network element to stop feeding back status detection messages to network elements in the network layer normally, Make the network element judge that the active link fails and switch to the standby link;

Or include a first instruction sending submodule, which is used to directly send an instruction to switch to a backup link to a network element in the network layer, so that the network element is switched from the active link in the network layer to the backup link .

In an embodiment of the invention, the second link switching module includes a second triggering submodule, configured to trigger the convergence active network element to re-feed back a normal state detection message to the network element in the network layer, Make the network element judge that the failure of the active link is eliminated and switch to the standby link;

Or include a second instruction issuing submodule, which is used to directly send an instruction to switch to the active link to the network element in the network layer, so that the network element switches from the backup link in the network layer to the active link superior.

In one embodiment of the invention, the first network layer is a three-layer virtual private network layer, and the first network element is a core layer network element; the second network layer is a two-layer virtual private network layer, so The second network element is an access layer network element.

In order to solve the above-mentioned problems, the present invention also provides a kind of aggregation master network element in the networking, and the networking also includes a first network layer, a second network layer, and a convergence backup network element, which are respectively located in the first network layer and the The first network element and the second network element of the second network layer, the aggregation main network element and the aggregation standby network element are located at the convergence of the first network layer and the second network layer; the first network element is connected to the aggregation main network element The link is the active link of the first network layer; the link connecting the second NE and the aggregated active NE is the active link of the second network layer; the link connecting the first NE and the aggregated standby NE The link between the second NE and the aggregation standby NE is the backup link of the second network layer; the link between the aggregation master NE and the aggregation standby NE The path is an aggregation link; the aggregation main network element includes a memory and a processor; the memory is used to store instructions; the processor is used to call the instructions to perform the following steps:

Detect whether the active link of one of the two network layers and the aggregated link fail at the same time, if so, trigger the network element in the other network layer where the active link has not failed to The primary link in the layer is switched to the standby link.

The beneficial effects of the present invention are:

The present invention provides a network protection method, a device, and a main converged network element in the network. The network includes a first network layer and a second network layer, and the first network elements respectively located in the first network layer and the second network layer , the second network element, and the aggregation main network element and the aggregation backup network element located at the convergence of the first network layer and the second network layer; the link connecting the first network element and the aggregation main network element is the first network layer The link connecting the second NE and the aggregated active NE is the active link of the second network layer; the link connecting the first NE and the aggregated standby NE is the first network layer Standby link; the link connecting the second network element and the aggregation standby network element is the backup link of the second network layer; the link connecting the aggregation main network element and the aggregation standby network element is the aggregation link; detection When the active link and aggregation link of one of the two network layers fail at the same time, trigger the NEs in the other network layer whose active link has not failed to switch from the active link in this network layer to The link is switched to the standby link, so as to realize the linkage protection of the networking and avoid the interruption of service flow.

Description of drawings

FIG. 1 is a schematic diagram of a networking structure provided in Embodiment 1 of the present invention;

FIG. 2 is a first schematic flow diagram of a network protection method provided in Embodiment 1 of the present invention;

FIG. 3 is a second schematic flow diagram of a network protection method provided in Embodiment 1 of the present invention;

FIG. 4 is a schematic structural diagram of a network protection device provided in Embodiment 2 of the present invention;

FIG. 5 is a schematic diagram of the L3VPN+L2VPN networking structure provided in Embodiment 3 of the present invention;

FIG. 6 is a schematic diagram of four state transitions provided in Embodiment 3 of the present invention;

FIG. 7 is a schematic diagram of an L3VPN network link failure provided in Embodiment 3 of the present invention;

FIG. 8 is a schematic diagram of L3VPN network link elimination provided in Embodiment 3 of the present invention;

FIG. 9 is a schematic diagram of an L2VPN network link failure provided in Embodiment 3 of the present invention;

FIG. 10 is a schematic diagram of the elimination of L2VPN network links provided in Embodiment 3 of the present invention;

FIG. 11 is a schematic diagram of link failures of the L2VPN network and the L3VPN network provided in Embodiment 3 of the present invention.

detailed description

The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

Embodiment one:

Please refer to FIG. 1, the networking in this embodiment includes a first network layer and a second network layer, a first network element and a second network element located at the first network layer and the second network layer respectively, and a network element located at the second network layer. The aggregation main network element and the aggregation standby network element at the convergence of the first network layer and the second network layer; the link connecting the first network element and the aggregation main network element is the main link of the first network layer; the second network The link connecting the main network element and the aggregation main network element is the active link of the second network layer; the link connecting the first network element and the aggregation standby network element is the backup link of the first network layer; the second network element and the The link that aggregates the connection of the standby network element is the standby link of the second network layer; the link that aggregates the connection between the active network element and the aggregate standby network element is the aggregated link. Under normal circumstances, both the first NE and the second NE work on the active links of their respective network layers, and the transparent transmission of relevant information is realized by converging the active NEs; when the first NE and the second NE When the active link of the respective network layer fails, it will be switched to the backup link of the network layer; after the fault of the failed active link is eliminated, the backup link will be switched back to the active link.

Referring to Figure 2, the network protection method in this embodiment includes:

Step 201: Detect whether the active link of one of the network layers in the two network layers and the above-mentioned aggregated link fail at the same time, if so, go to step 202; otherwise, continue to detect;

Step 202: triggering a network element in another network layer where the active link has not failed to switch from the active link in the network layer to the standby link.

For example, when it is detected that the active link in the first network layer and the above-mentioned aggregated link fail at the same time, the first network element in the first network layer will switch to the backup link in the first network layer; It is necessary to trigger the switchover of the second network element in the second network layer where the main link has not failed to the backup link in the second network layer; otherwise, after the service flow in the second network layer reaches the converging main network element An interruption will occur. Through this linkage switching, the occurrence of the above situation can be avoided. On the contrary, when the active link in the second network and the above-mentioned aggregated link fail at the same time, but the active link in the first network does not fail, the process of linkage switching is similar to the above process.

Please refer to Fig. 3, on the basis of Fig. 2, the network protection method in this embodiment further includes:

Step 203: Detect whether the failure of the failed active link and/or aggregation link is eliminated, if so, go to step 204; otherwise, continue to detect;

Step 204: triggering a network element in another network layer whose active link has not failed to switch back to the active link from the standby link in the network layer.

For example, when the failure of the active link in the first network layer where the above failure occurs is eliminated, the first network element in the first network layer will switch back to the active link at this time; trigger the first network element in the second network layer The second network element also switches back to the active link from the standby link in the network layer. For another example, although the failure of the main link in the first network layer that has failed has not been eliminated, the failure of the above-mentioned aggregation link has been eliminated. At this time, the convergence of the main network element can realize the first network element and The transparent transmission of messages between the second network elements triggers the second network element in the second network layer to switch back to the active link from the backup link in the network layer at this time; When the faults of both the active link and the aggregated link in the network layer are eliminated, the switching process is the same as the above-mentioned switching process for eliminating the active link fault, which will not be repeated here.

In this embodiment, detecting whether there is a simultaneous failure of the active link and the aggregation link of one of the two network layers includes:

Detect whether the status detection message sent by the network element in one of the two network layers can only be received normally; if yes, it indicates that the active link and the aggregation link in the other network layer fail at the same time.

For example, in Figure 1, the converging master network element only receives the status detection packet sent by the first network element, but cannot receive the status detection packet sent by the second network element, which indicates that the master network element in the second network layer If the active link and the aggregated link between the aggregation master network element and the aggregation standby network element fail at the same time, otherwise the aggregation master network element can receive the status detection message sent by the second network element. It should be noted that in this embodiment, different network layers may adopt different status detection mechanisms, and corresponding status detection messages may also adopt different forms.

In this embodiment, triggering a network element in another network layer where the active link has not failed to switch from the active link in the network layer to the standby link includes:

Trigger the convergence of the active network element to stop feeding back the status detection message to the network element in the network layer, so that the network element judges that the active link fails and switches to the standby link;

Or directly send an instruction to switch to the standby link to the network element in the network layer, so that the network element switches from the active link in the network layer to the standby link.

In this embodiment, triggering a network element in another network layer where the active link has not failed to switch back to the active link from the standby link in the network layer includes:

Trigger the convergence of the active network element to re-feed back the normal state detection message to the network element in the network layer, so that the network element can judge that the failure of the active link is eliminated and switch to the standby link;

Or directly send an instruction to switch to the active link to the network element in the network layer, so that the network element switches from the backup link in the network layer to the active link.

Specifically, the first network layer in this embodiment may be a three-layer virtual private network layer (L3VPN, LayerThreeVirtualPrivateNetwork), and the first network element is a core layer network element; the second network layer is a two-layer virtual private network layer (L2VPN, LayerTwoVirtualPrivateNetwork) networking, the second network element is the access layer network element.

Embodiment two:

The networking provided by this embodiment is the same as that shown in Figure 1; this embodiment also provides a networking protection device, as shown in Figure 4, including a fault detection module and a first link switching module:

The failure detection module is used to detect whether the active link of one of the network layers in the two network layers and the aggregation link fail simultaneously, and if so, notify the first link switching module; in this embodiment, the failure detection module includes The message detection submodule is used to detect whether the state detection message sent by the network element in one of the network layers in the two network layers can only be received normally; The link and the aggregated link fail simultaneously.

The first link switching module is used to trigger a network element in another network layer where the active link has not failed to switch from the active link in the network layer to the standby link according to the notification. In this embodiment, the first link switching module specifically includes a first triggering sub-module, which is used to trigger the convergence of the active network element to stop feeding back the normal state detection message to the network element in the network layer, so that the network element can judge the active link In the event of a link failure, switch to the backup link. Or include a first instruction sending submodule, which is used to directly send an instruction to switch to a backup link to a network element in the network layer, so that the network element is switched from the active link in the network layer to the backup link .

The networking protection device also includes a second link switching module, which is used to trigger a network element in another network layer whose main link has not failed when the failure of the failed main link and/or aggregation link is eliminated. Switch back to the active link from the standby link in the network layer.

In this embodiment, the second link switching module includes a second triggering sub-module, which is used to trigger the converging active network element to re-feed back the normal state detection message to the network element in the network layer, so that the network element can judge the active link The fault is eliminated and switched to the standby link;

Or include a second instruction issuing submodule, which is used to directly send an instruction to switch to the active link to the network element in the network layer, so that the network element switches from the backup link in the network layer to the active link superior.

The network protection device in this embodiment may be a converging main network element in the network, or other third-party devices outside the network.

The first network layer in the present embodiment can be three layers of virtual private network layers (L3VPN, LayerThreeVirtualPrivateNetwork), and the first network element is a core layer network element; The second network layer is a two-layer virtual private network layer (L2VPN, LayerTwoVirtualPrivateNetwork) group network, and the second network element is an access layer network element.

Embodiment three:

This embodiment provides a main convergence network element in the network shown in FIG. 1, the main convergence network element includes a memory and a processor; the memory is used to store instructions; the processor is used to call the instructions to execute the instructions in the first embodiment the steps shown. In the following, the first network layer is the three-layer virtual private network layer (L3VPN, LayerThreeVirtualPrivateNetwork), the first network element is the core layer network element; the second network layer is the two-layer virtual private network layer, namely (L2VPN, LayerTwoVirtualPrivateNetwork) networking , the second network element is an access layer network element as an example for illustration, as shown in FIG. 5 . In this embodiment, link switching is realized by L3VPNFRR (fast rerouting, FastReRoute) in L3VPN, and the corresponding state detection message is a BFD (BidirectionalForwardingDetection, bidirectional forwarding detection) message; The corresponding state detection message is a CCM (Continuity check message, continuity check message) message. For ease of description, BFD packets and CCM packets are collectively referred to as OAM packets below. In addition, in this embodiment, the detection of the state message corresponding to the L3VPN can be realized through the L3VPN control module set on the main network element of the convergence, and the detection of the state message corresponding to the L2VPN can be realized through the L2VPN control module set on the main network element of the convergence accomplish. The networking shown in Figure 5 has the following four states:

In state 1, both the L3VPN control module and the L2VPN module on the aggregation master NE allow the OAM packets sent to the corresponding core NE and access NE, and both detect that they can receive the OAM packets sent by the core NE and access NE. OAM message, and there is no alarm at the same time;

State 2-1, the L3VPN control module releases the local OAM message, detects that the OAM message sent by the core network element cannot be received, and reports an alarm to the OAM; the L2VPN module blocks the local OAM message, and can detect the OAM message of the access network element. packets, OAM reports alarms.

State 2-2, the L2VPN control module releases the local OAM packets, detects that no OAM packets from the access network element are received, and reports an alarm to the OAM; the L3VPN module blocks the local OAM packets, and can detect the core network element OAM packets , OAM reports an alarm.

In state 3, both the L3VPN control module and the L2VPN control module allow local OAM packets, but both cannot detect the OAM packets sent by the core network element and the access network element, and the OAM reports an alarm.

Please refer to Figure 6 for the transition process of the above four states, as follows:

In state 1, when the L3VPN control module detects that the core network element OAM message cannot be received, the OAM reports an alarm and enters state 2-1; when the L2VPN control module detects no access network element OAM message, the OAM reports an alarm, Going to state 2-1 goes to state 2-2.

In state 2-1, when the L3VPN control module detects that the OAM message from the core network element can be received, and the OAM alarm disappears, enter state 1; when the L2VPN control module cannot detect the OAM message from the access network element, OAM reports an alarm, and enter state 3.

In state 2-2, when the L2VPN control module detects that the OAM message from the access network element can be received, and the OAM alarm disappears, enter state 1; when the L3VPN control module cannot detect the OAM message from the core network element, OAM reports an alarm, and enters state 3.

In state 3, when the L2VPN control module detects that the OAM message from the opposite end can be received, it enters state 2-1; when the L3VPN control module detects that the OAM message from the opposite end can be received, it enters state 2-2.

In this embodiment, the L2VPN and L3VPN networking protection linkage method includes the following steps:

In the first step, the main network element of the aggregation layer monitors the OAM status of the L2VPN network and the L3VPN network from the main network element of the aggregation layer in the protection network based on MPLS-TP L2VPN and L3VPN service bridging.

In the second step, when the converging master network element detects that the local end cannot receive the OAM message from the adjacent network and reports an OAM alarm, it will block the network element from sending OAM messages to another adjacent network to reach the L2VPN network and The purpose of L3VPN network linkage.

In the second step described in this embodiment, further meanings include:

1. When a state 2-1 failure occurs on the L3VPN network, the L3VPN network of the local network element cannot receive OAM packets from the peer end, and when the L3VPN network reports an OAM alarm, the L2VPN network of the local network element is blocked from sending to the network element at the access layer. OAM message, so the OAM of the access network element detects the failure of the main path, and the service is switched to the backup path, thus completing the linkage from the L3VPN network to the L2VPN;

2. When the state 2-2 occurs on the L2VPN network, the L3VPN network of the local network element cannot receive the OAM message from the peer end, and the L3VPN network reports an OAM alarm, blocking the L3VPN network of the local network element from sending OAM messages to the core layer network element. , so the access layer network element OAM detects the failure of the main path, and the service is switched to the backup path, thus completing the linkage from the L2VPN network to the L3VPN.

3. When the above state 3 failure occurs on the L2VPN network and the L3VPN network, the OAMs of the two networks cannot receive the OAM packets of the adjacent network, and both report OAM alarms. In this case, the OAM packets are not blocked.

Step 3: When the converging active network element detects that the OAM of the local network element can receive the OAM message of the adjacent network, the OAM alarm disappears, and the blocking of the OAM message of the local network element is released, so that the service is restored from the backup path to the active network element. path.

In the third step described in this embodiment, further meanings include:

1. When it is detected that the OAM alarm of the L3VPN network disappears and the OAM message from the opposite end can be received, the blockage of the OAM message on the L2VPN network of the local network element is released, so that the service of the network element at the access layer is restored from the backup path to the active one. path.

2. When it is detected that the OAM alarm of the L2VPN network disappears and the OAM message from the opposite end can be received, the blocking of the OAM message of the local network element L3VPN network is released, so that the service of the network element at the access layer is restored from the backup path to the active one. path.

The protection method when the above fault occurs will be described in detail below in conjunction with the accompanying drawings.

Please refer to Figure 7-8, which shows the failure of the L3VPN network link.

As shown in Figure 7, when the two links ① and ② fail, the FRR protection of the network element at the core layer detects the failure of the active path and switches to the backup path. The L3VPN module of the active network element at the aggregation layer detects that the core When the BFD packet of the layer NE is down, the BFD status is down, which triggers the convergence of the master NE to block the CCM packets of the L2VPN network. Therefore, the access NE cannot receive the CCM packet of the master NE at the convergence layer, and the master pseudowire OAM The LOC alarm is reported, and then the pseudowire dual-homing protection is triggered to switch to the backup path, so that the L3VPN and L2VPN networks complete the switching linkage.

As shown in Figure 8, when one or both of the links ① and ② return to normal (Figure 8 uses the recovery of both as an example), the core network element FRR detects that the main path alarm disappears, and the main path The path recovery is available, so FRR restores to the active path; at the same time, at the aggregation layer, the active network element, the L3VPN module detects that the L3VPN network can receive the core layer BFD packet, the BFD status is UP, and the alarm disappears, triggering the aggregation layer. The network element unblocks the OAMCCM message of the L2VPN network; then the access layer network element detects and receives the CCM message of the active network element at the aggregation layer, the LOC alarm disappears, and the active path is available, so the pseudo-wire dual-homing protection returns to the active path. The path is used, so that the L3VPN and L2VPN networks can restore linkage.

Please refer to Figure 9-10, which shows the failure of the L3VPN network link.

As shown in Figure 9, when the two links ③ and ② fail, the pseudowire dual-homing protection of the access network element detects the failure of the main path and switches to the backup path; at the same time, the main network element at the aggregation layer, the L2VPN The module detects that it cannot receive the pseudo-wire CCM message from the NE at the access layer, reports a LOC alarm, and triggers the convergence of the main NE to block the BFD message of the L3VPN network, so the NE at the core layer cannot receive the message from the main NE at the aggregation layer. BFD packets, the BFD state is down, and FRR protection is triggered to switch to the backup path, so that the L2VPN and L3VPN networks complete the switching linkage.

As shown in Figure 10, in this embodiment, when one or both of the links ③ and ② are restored to normal (Figure 10 uses both of them as an example to illustrate), the access layer network element detects the main path The alarm disappears and the active path becomes available again, so the pseudowire dual-homing returns to the active path; at the same time, the active network element at the aggregation layer, the L2VPN module detects that the L2VPN network can receive the pseudowire CCM message at the access layer, and the LOC When the alarm disappears, the aggregation master NE is triggered to unblock the BFD packets of the L3VPN network; then the core NE can detect and receive the BFD packets from the master NE of the aggregation layer, the BFD status is UP, and the master path is available, so the FRR protection is restored to the active path, so that the L2VPN and L3VPN networks complete the recovery linkage.

Please refer to Figure 11, which shows the situation that both the L3VPN network and the L2VPN network have link failures, and at this time, the aggregation master network element becomes an isolated island.

As shown in Figure 11, when the three links ①, ②, and ③ fail, the L2VPN control module of the main network element at the aggregation layer detects that it cannot receive the pseudowire CCM message from the access network element, reports the LOC alarm, and the L3VPN control The module detects that the BFD message from the core network element cannot be received, and the BFD status is down. In this case, neither the L2VPN control module nor the L3VPN control module blocks the CCM message or the BFD message. At this time, the link recovery will have the following situations:

The first case: when ① the link returns to normal, the network state becomes the state shown in Figure 9, and then go to the situation shown in Figure 9 for processing.

The second case: when ③ the link returns to normal, the network state becomes the state shown in Figure 7, and the situation shown in Figure 7 is turned to for processing.

The present invention solves the problem of one-way service interruption caused by the non-node failure of the main network element of the aggregation layer and the isolation of the L3VPN (or L2VPN) network in the prior art, through the linkage of protection between the L2VPN network and the L3VPN network, Greatly improved the reliability of the network.

The above content is a further detailed description of the present invention in conjunction with specific embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deduction or replacement can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (13)

1. A network protection method, wherein the network comprises a first network layer and a second network layer, a first network element and a second network element located at the first network layer and the second network layer respectively, and a network element located at the first network layer The aggregation main network element and the aggregation standby network element at the convergence of the network layer and the second network layer; the link connecting the first network element and the aggregation main network element is the main link of the first network layer; the second network element The link connected to the main network element of the aggregation is the main link of the second network layer; the link connecting the first network element to the standby network element of the aggregation is the backup link of the first network layer; the second network element and the aggregation The link connected by the backup network element is a backup link of the second network layer; the link that aggregates the connection between the main network element and the backup network element is an aggregation link; it is characterized in that the method includes: Detect whether the active link of one of the two network layers and the aggregated link fail at the same time, if so, trigger the network element in the other network layer where the active link has not failed to The primary link in the layer is switched to the standby link. 2. The networking protection method according to claim 1, characterized in that, when the failure of the failed active link and/or aggregated link is eliminated, trigger another network where the active link does not fail The network elements in the layer switch back to the active link from the standby link in the network layer. 3. The networking protection method according to claim 2, wherein detecting whether the active link of one of the network layers in the two network layers and the simultaneous failure of the aggregation link occurs includes: Detect whether the status detection message sent by the network element in one of the network layers of the two network layers can only be received normally; if so, the active link in the other network layer and the aggregation link simultaneously malfunction. 4. The networking protection method according to claim 3, characterized in that, the network element in another network layer in which the triggering active link has not failed is switched from the active link in the network layer to the backup Links include: Triggering the aggregation active network element to stop feeding back the status detection message to the network element in the network layer normally, so that the network element judges that the active link fails and switches to the backup link; Or directly send an instruction to switch to the standby link to the network element in the network layer, so that the network element switches from the active link in the network layer to the standby link. 5. The networking protection method according to claim 4, characterized in that, the network element in another network layer that does not fail to trigger the active link switches back to the active link from the standby link in the network layer. Links include: Triggering the aggregation active network element to feed back a normal state detection message to the network element in the network layer again, so that the network element judges that the failure of the active link is eliminated and switches to the backup link; Or directly send an instruction to switch to the active link to the network element in the network layer, so that the network element switches from the backup link in the network layer to the active link. 6. The networking protection method according to any one of claims 1-5, wherein the first network layer is a three-layer virtual private network layer, and the first network element is a core layer network element; The second network layer is a layer-2 virtual private network layer, and the second network element is an access layer network element. 7. A network protection device, the network includes a first network layer, a second network layer, a first network element and a second network element located at the first network layer and the second network layer respectively, and a network element located at the first network layer The aggregation main network element and the aggregation standby network element at the convergence of the network layer and the second network layer; the link connecting the first network element and the aggregation main network element is the main link of the first network layer; the second network element The link connected to the main network element of the aggregation is the main link of the second network layer; the link connecting the first network element to the standby network element of the aggregation is the backup link of the first network layer; the second network element and the aggregation The link connected by the backup network element is a backup link of the second network layer; the link that aggregates the connection between the main network element and the backup network element is an aggregation link; it is characterized in that the device includes a fault detection module And the first link switching module: The failure detection module is used to detect whether the active link of one of the two network layers and the aggregation link fail at the same time, and if so, notify the first link switching module; The first link switching module is configured to trigger a network element in another network layer whose active link has not failed to switch from the active link in the network layer to the standby link according to the notification. 8. The networking protection device according to claim 7, further comprising a second link switching module, configured to trigger A network element in another network layer where the active link has not failed is switched back to the active link from the standby link in the network layer. 9. The networking protection device according to claim 8, wherein the fault detection module includes a message detection sub-module for detecting whether only one of the two network layers can normally receive The status detection message sent by the network element in the network layer; if so, it is determined that the active link in the other network layer and the aggregated link are faulty at the same time. 10. The network protection device according to claim 9, wherein the first link switching module includes a first triggering sub-module, configured to trigger the aggregation main network element to stop sending to the network layer The network element normally feeds back the state detection message, so that the network element judges that the active link fails and switches to the standby link; Or include a first instruction sending submodule, which is used to directly send an instruction to switch to a backup link to a network element in the network layer, so that the network element is switched from the active link in the network layer to the backup link . 11. The networking protection device according to claim 10, wherein the second link switching module includes a second triggering sub-module, configured to trigger the convergence master network element to reconnect to the network element in the network layer. The network element normally feeds back the status detection message, so that the network element judges that the failure of the active link is eliminated and switches to the standby link; Or include a second instruction issuing submodule, which is used to directly send an instruction to switch to the active link to the network element in the network layer, so that the network element switches from the backup link in the network layer to the active link superior. 12. The networking protection device according to any one of claims 7-11, wherein the first network layer is a three-layer virtual private network layer, and the first network element is a core layer network element; The second network layer is a layer-2 virtual private network layer, and the second network element is an access layer network element. 13. A converging main network element in a networking, the networking also includes a first network layer, a second network layer, and a converging standby network element, respectively located in the first network layer of the first network layer and the second network layer network element, the second network element, the aggregation main network element and the aggregation standby network element are located at the convergence of the first network layer and the second network layer; the link connecting the first network element and the aggregation main network element is the first network layer The active link; the link connecting the second NE and the aggregated active NE is the active link of the second network layer; the link connecting the first NE and the aggregated standby NE is the backup of the first network layer link; the link connecting the second network element and the aggregation standby network element is the backup link of the second network layer; the link connecting the aggregation main network element and the aggregation standby network element is the aggregation link; its characteristics In that, the convergence master network element includes a memory and a processor; the memory is used to store instructions; and the processor is used to invoke the instructions to perform the following steps: Detect whether the active link of one of the two network layers and the aggregated link fail at the same time, if so, trigger the network element in the other network layer where the active link has not failed to The active link in the layer is switched to the standby link.