WO2011029249A1

WO2011029249A1 - Protection method and device for an ethernet tunnel

Info

Publication number: WO2011029249A1
Application number: PCT/CN2009/075570
Authority: WO
Inventors: 王斌; 吴少勇
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-09-09
Filing date: 2009-12-14
Publication date: 2011-03-17
Also published as: CN102025585A

Abstract

A protection method for an Ethernet tunnel is provided by the invention. More than one protection entities are set for one work entity in an Ethernet protection domain. The work entity and the protection entities share two same endpoint bridges. The method includes that: when an endpoint bridge detects that the work entity is in fault it switches the protected tunnel on the work entity to a protection entity, namely it modifies the exit port of the forwarding item of the protected tunnel associated with the port of the work entity to the port of the selected protection entity, and notifies the other endpoint bridge to perform port switching. A protection device for an Ethernet tunnel is also provided by the invention. The invention enables rapid protection for Traffic Engineered Service Instances (TESI), thus enhancing the robustness of the Provider Backbone Bridge Traffic Engineering (PBB-TE) network, and improving network performance.

Description

Ethernet tunnel protection method and device

The present invention relates to a protection switching technology in Ethernet, and in particular, to a method and apparatus for protecting an Ethernet tunnel. Background technique

With the concept of Carrier Ethernet (CE), in order to meet the ever-increasing high data rate requirements of telecommunication networks, the connection-oriented Ethernet technology (PBT, Provider Backbone Transport) was released in 2005. The month was raised. Since then, operators at home and abroad have adopted PBT technology networking, which provides a good start for the development of PBT technology in metropolitan area networks.

The foundation of PBT technology is the Carrier Backbone Bridge (PBB) technology defined by the IEEE, Institute of Electrical and Electronics Engineer (802.1ah). The IEEE refers to PBT technology as the backbone of operators supporting traffic engineering. Bridging Technology (PBB-TE, Provider Backbone Bridge Traffic Engineering). PBB-TE technology is based on PBB technology and its core is an improved technology for PBB. In the PBT technology, the source device of the CE is inserted into the destination MAC address of the backbone network (B-DA, Backbone Destination MAC Address) at the head of the packet, and the source MAC address of the backbone network (B-SA, Backbone Source MAC Address). A virtual local area network (B-VLAN, Backbone Virtual Local Area Network) and a service instance tag (I-TAG, Service Instance TAG). The forwarding path between the source device and the destination device of the CE is statically configured in advance. The CE device in the middle can forward the data frame based on the B-DA and B-VID in the forwarding table. The forwarding efficiency is high.

In order for Ethernet to meet telecom grade standards, PBB-TE typically employs protection techniques. FIG. 1 is a schematic diagram of end-to-end linear protection of an Ethernet tunnel in the prior art, as shown in FIG. Lines represent end-to-end working tunnels, dotted lines indicate end-to-end backup tunnels, and dotted lines with double-headed arrows indicate VLANs. The end-to-end primary tunnel TN1 of a traffic engineering service instance (TESI) is: PE1 → P1 → P2 → P3 → PE2, and PE1 and PE2 are the ends of the tunnel instance. The backup tunnel TN2 is: PE1 → P5 → P6 → PE2. TN2 is the end-to-end backup tunnel of the traffic engineering service instance. To distinguish the primary tunnel TN1 and the backup tunnel TN2, when pre-configuring, specify B- for the primary tunnel TN1. VLAN1, the standby tunnel TN2 specifies B-VLAN2. When the end-to-end primary tunnel TN1 fails, the data flow can be switched to the backup tunnel TN2.

PBB-TE uses the Connectivity Fault Management (CFM) mechanism in IEEE 802. lag to continuously monitor the tunnel status in the network. When the primary tunnel fails, the service is automatically transferred to the pre-established alternate path, and the tunnel protection technology is implemented.

In the prior art, tunnel connectivity is detected by sending a Continuity Check Message (CCM) defined in IEEE 802.1ag in a tunnel. Figure 2 is a schematic diagram of the end-to-end tunnel protection principle in PBB-TE. As shown in Figure 2, the solid line in the figure indicates the end-to-end working tunnel, and the dotted line indicates the end-to-end backup tunnel. The tunnel endpoints PE1 and PE2 send CCMs to each other along the primary tunnel TN1 and the backup tunnel TN2. The CCMs of the primary tunnel and the backup tunnel encapsulate B-VLAN1 and B-VLAN2 respectively. This method implements full path protection of the tunnel.

To achieve protection for two-way communication, a method of configuring TESI can be used. A point-to-point traffic engineering service instance TESI consists of a pair of bidirectional point-to-point ESP (IP Encapsulating Security Payload). A detailed description of the triplet and TESI can be found in the IEEE 802.1Qay standard.

Although the end-to-end protection technology of PBB-TE can effectively protect the tunnel, this end-to-end protection scheme not only protects the switching time longer, but also involves more nodes. Therefore, the IEEE organization proposed a PBB-TE local protection scheme. Figure 3 is a schematic diagram of the PBB-TE mid-section protection principle. As shown in Figure 3, the thin solid line in the figure represents the end-to-end working tunnel, the thin dotted line represents the end-to-end backup tunnel, the thick solid line represents the working segment, and the thick dotted line Lines represent end-to-end backup segments, A dotted line with a double-headed arrow indicates a VLAN. P1-P2-P3 is a physical link (called a segment) carrying a partial path of the end-to-end primary tunnel TN1 (PE1 → P1 → P2 → P3 → PE2), which can be performed by backing up the P1-P4-P3 physical link. protection. The biggest difference between the PBB-TE segment protection scheme and the PBB-TE end-to-end protection is that the segment protection scheme is based on physical link protection, and the end-to-end protection scheme is tunnel-based protection.

In order to implement the segment protection function in PBB-TE, CCM messages need to verify their integrity on both the working and protection entities of the protection domain. Figure 4 is another schematic diagram of the PBB-TE mid-section protection principle. As shown in Figure 4, the thin solid line in the figure represents the end-to-end working tunnel, the thick solid line indicates the working segment, and the thick dotted line indicates the end-to-end backup segment. The CCMs are respectively sent between the endpoints P1 and P3 along the working entity (P1—P2-P3) and the protection entity (P1-P4-P3), and the CCMs of the working entity and the protection entity respectively encapsulate the corresponding B-VLANs. The specific B-VLAN mode encapsulation has not been determined. The above method achieves good protection for the local path (physical path) of the tunnel.

Although the end-to-end TESI protection technology of PBB-TE can effectively protect the tunnel, this end-to-end TESI protection scheme protects the switching time. The segment-based protection switching described above does not yet have mature technology. Summary of the invention

In view of this, the main object of the present invention is to provide a method and device for protecting an Ethernet tunnel, which can enhance the robustness of the PBB-TE network and improve the network performance of the Ethernet.

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

A method for protecting an Ethernet tunnel, where one or more protection entities are set for one working entity in an Ethernet protection domain, where the working entity and the protection entity have the same two endpoint bridges; the method includes:

When the endpoint bridge detects that the working entity is faulty, the protected tunnel on the working entity is switched to a protection entity. Preferably, the switching the protected tunnel on the working entity to a protection entity comprises:

The outbound port of the forwarding entry of the protected tunnel associated with the port of the working entity is modified to the port of the selected protection entity.

Preferably, the port of the protection entity is selected, including:

When the endpoint bridge determines that there is an idle protection entity, the idle protection entity with the smallest port label is selected as the protection entity to be switched, and the outbound port of the forwarding entry of the protected tunnel associated with the port of the working entity is modified to be Select the port of the protection entity and notify the other endpoint bridge to perform port switching.

Preferably, the port of the protection entity is selected, including:

When the endpoint bridge determines that there is no idle protection entity, the protection entity with the lowest priority is selected as the protection entity to be switched, and the outbound port of the forwarding entry of the protected tunnel associated with the port of the working entity is modified to The port of the selected protection entity is notified, and the other endpoint bridge is notified to perform port switching.

Preferably, the method further includes:

When the endpoint bridge detects that the working entity fails, the egress port of the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located is modified to be the port of the working entity.

Preferably, the other end bridge is notified to perform port switching, including:

The other endpoint bridge is notified by a port modified to be an outgoing port of the forwarding entry, and the other endpoint bridge receives a notification of port switching through a corresponding one of the other endpoint bridges by the protection entity in which the egress port is located.

Preferably, the method further includes:

After receiving the notification of the switching, the another endpoint bridge modifies the egress port of the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located to the received switching The port of the notification.

A protection device for an Ethernet tunnel, comprising:

a setting unit, configured to set one or more protection entities for one working entity in an Ethernet protection domain, where the working entity and the protection entity have the same two endpoint bridges;

a detecting unit, configured to detect whether the working entity is faulty, and trigger a switching unit when the fault occurs;

The switching unit is configured to switch the protected tunnel on the working entity to a protection entity. Preferably, the switching unit includes:

a determining unit, configured to determine whether there is an idle protection entity, triggering the selecting unit when present; and selecting a unit, configured to select an idle protection entity with the smallest port label as the protection entity to be switched;

a modifying unit, configured to modify an egress port of the forwarding entry of the protected tunnel associated with the port of the working entity to a port of the selected protection entity;

The notification unit is configured to notify another endpoint bridge to perform port switching.

Preferably, the determining unit determines that there is no idle protection entity, triggering the selecting unit to select the protection entity with the lowest priority as the protection entity to be switched, and the modifying unit is associated with the port of the working entity. The outbound port of the forwarding entry of the protected tunnel is modified to the port of the selected protection entity, and the notification unit notifies the other endpoint bridge to perform port switching.

Preferably, when the detecting unit detects that the working entity fails, the modifying unit triggers the modifying unit to modify the egress port of the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located to be the working entity. port.

Preferably, the notification unit notifies another endpoint bridge by modifying a port that is an outbound port of the forwarding entry, and the other endpoint bridge receives the notification of the port switching through the corresponding port of the protection entity where the egress port is located in the other endpoint bridge. .

Preferably, the device further includes: The receiving unit is configured to receive the notification of the switching, and trigger the modifying unit to modify the egress port of the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located to the port that receives the notification of the switching.

In the present invention, by setting more than one protection entity for the working entity, and setting the endpoint bridge for the working entity and the protection entity in the Ethernet protection domain, when the endpoint bridge detects that the working entity is faulty or the fault disappears, the current service is modified. The outbound interface of the forwarding entry performs service switching. The present invention can quickly implement TESI fast protection, enhance the robustness of the PBB-TE network, and improve network performance. DRAWINGS

1 is a schematic diagram of end-to-end linear protection of an Ethernet tunnel in the prior art;

Figure 2 is a schematic diagram of the end-to-end tunnel protection principle in PBB-TE;

Figure 3 is a schematic diagram of the PBB-TE mid-section protection principle;

Figure 4 is another schematic diagram of the PBB-TE mid-section protection principle;

5 is a flowchart of a method for protecting an Ethernet tunnel according to the present invention;

6 is a schematic structural diagram of a working entity failure and an idle protection entity; FIG. 7 is a schematic diagram of a protection implementation structure when a working entity fails and has an idle protection entity; FIG. 8 is a schematic diagram of a working entity failure and no idle protection entity FIG. 9 is a schematic diagram of a protection implementation structure when a working entity fails and there is no idle protection entity; FIG. 10 is a schematic structural diagram of a protection device of an Ethernet tunnel according to the present invention. The basic idea of the present invention is: by setting more than one protection entity for the working entity, and setting the endpoint bridge for the working entity and the protection entity in the Ethernet protection domain, when the endpoint bridge detects that the working entity is faulty or the fault disappears, The service is switched by modifying the outbound interface of the forwarding entry of the current service, and the present invention can quickly implement TESI fast protection and enhance the PBB-TE network. Robustness improves network performance.

The present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 5 is a flowchart of a method for protecting an Ethernet tunnel according to the present invention. As shown in FIG. 5, the method for protecting an Ethernet tunnel of the present invention includes the following steps:

Step 501: Configure a "protection domain" on the specified Ethernet zone for the protected tunnel. The protection domain includes a working entity and N corresponding protection entities, where N is a natural number. The working entity and the protection entity have the same two endpoint bridges. A protection domain is used to protect a group of protected domains.

TESI. The structure of the endpoint bridge, working entity and protection entity is shown in Figure 6, Figure 7, Figure 8, or Figure 9.

Step 502: Configure a protected tunnel as a protection group on the endpoint bridge. The protection group includes a set of ports connected to the working entity and N backup ports connected to the protection entity. The priority of the port corresponds to the priority of the served service on the entity (path) to which the port is connected.

Step 503: The endpoint bridge detects whether the working entity has failed. If a failure occurs, step 504 is performed, and if no failure occurs, the working entity continues to be detected.

Step 504: Detecting that the working entity has failed. The endpoint bridge has a backup port in the protection group where the connected protection entity is idle and has no fault. If yes, go to step 505, otherwise go to step 506. After detecting the failure of the working entity, it continues to detect whether a protection entity is set for the working entity, and detects whether the protection entity of the working entity is idle and the port is not faulty. If there is a failure, it means that the service flow on the working entity cannot be performed. Switch to the protected entity of the port failure.

Step 505: The endpoint bridge selects the one with the smallest label in the backup port, and proceeds to step 507. In the present invention, the backup port that is idle in random can also be used as the port for protection switching. Generally, the port label matches the priority of its service, and the smallest port number also means that The service carried by the port has a lower priority. After the service on the working entity is switched to the port with the lowest priority, if the corresponding service flow passes after the port, the service flow affecting the port is for the user. The influence is also limited.

Step 506: The endpoint bridge selects the backup port with the lowest priority and the connected protection entity has no fault, and proceeds to step 507. If there is no free port, only one of the ports with the service flow can be selected as the switching object. In this case, the port through which the traffic with the lowest priority flows will be selected, even if the service of the port has an impact. It is the business with the lowest priority of business, and the impact of business is quite limited.

Step 507: The endpoint bridge modifies the egress port of the forwarding entry of the protected TESI tunnel associated with the port of the working entity to the selected backup port, and simultaneously moves to the other endpoint on the protection entity connected to the selected backup port. The bridge sends a switch notification message. The protection switching message can be implemented by carrying the RDI field in the CCM message, but is not limited to this method.

Step 508: After receiving the switching notification message, the another endpoint bridge modifies the egress port of the forwarding entry of the protected tunnel associated with the port of the working entity to the backup port that receives the switching notification message.

Step 509: The endpoint bridge detects whether the fault of the working entity has disappeared. If it disappears, step 510 is performed, otherwise, the fault state of the working entity is continuously detected.

Step 510: The endpoint bridge that detects the recovery of the working entity modifies the egress port of the forwarding entry of the protected tunnel associated with the selected backup port to a port connected to the working entity.

Figure 6 shows the structure of the working entity when there is a failure and there is an idle protection entity. As shown in Figure 6, the protection domain protects the local bearer links of TESI-1, TESI-2, TESI-3 and TESI-4. There are 1 working entity and 3 protection entities in the protection domain. In the case of no fault, TESI-1, TESI-2, TESI-3 and TESI-4 pass through the protection domain by the working entity. Both Endpoint Bridge 1 and Endpoint Bridge 2 are configured with a protection group. The protection group has one working port and three backup ports. The P4 ports of both are given the priority of the TESI-5 service, P2 and P3. The ports are configured with the lowest priority Predecessor (because the protected entity connected to both is idle). It is important to note that TESI-5 simply passes through the protection domain but is not protected by the protection domain. Wherein, it is assumed that the B-VID of the ESP of the T (the destination address) of the TESI-1 is X, the B-VID of the reverse ESP is 2, and the B-VID of the ESP of the TESI-2 of the M is M, The B-VID of the reverse ESP is 4; the B-VID of the ESP of the TESI-3 is U, the B-VID of the reverse ESP is 6, and the B-VID of the EESI of the TESI-4 is J. 7. The B-VID of the reverse ESP is 8; the B-VID of the ESP of the TESI-5 is P for P9, and the B-VID of the reverse ESP is 10; TESI-1, TESI-2, TESI-3, See Figure 6 for specific forwarding entries for TESI-4 and TESI-5 in Endpoint Bridge 1 and Endpoint Bridge 2.

Figure 7 is a schematic diagram of the protection implementation structure when the working entity fails and has an idle protection entity. As shown in Figure 7, the working entity fails, and the endpoint bridge 1 detects the fault first. It checks the backup port in its own protection group. It is found that the backup ports P2 and P3 are idle, and the endpoint bridge 1 selects the P2 port with the smallest label in the free port. Then, Endpoint Bridge 1 modifies its own forwarding table, TESI-1 ( <X, 1> ), TESI-2 ( <M, 3> ), TESI-3 ( <U, 5> ), and TESI-4 ( < J, 7> ) The corresponding outgoing port of the forwarding entry is changed from P1 to P2. At the same time, the endpoint bridge 1 sends a switching notification message on the protection entity 1, wherein the switching notification message can be carried by using the RDI field in the CCM message, but is not limited to this manner. Endpoint Bridge 2 modifies its own forwarding table after receiving the switch notification message on protection entity 1, and sets TESI-1 ( <Y, 2> ), TESI-2 ( <Ν, 4> ), TESI-3 ( <V, 6> ) The outgoing port of the forwarding entry corresponding to TESI-4 ( <K, 8> ) is modified from P1 to Ρ2.

Figure 8 shows the structure of the working entity when there is a failure and there is no idle protection entity. As shown in Figure 8, the protection domain only protects TESI-1. There are one working entity and three protection entities in the protection domain. Next, TESI-1 passes through the protection domain by the working entity. TESI-2, TESI-3 and TESI-4 are not protected by a protection domain, and TESI-2, TESI-3 and TESI-4 are passed through the protection domain by the protection entity 1, the protection entity 2 and the protection entity 3, respectively. Both Endpoint Bridge 1 and Endpoint Bridge 2 are configured with a protection group. The protection group has one working port and three backup ports. Three backup ports are assigned. priority. The priorities of the P2, P3, and P4 ports of the two endpoint bridges are the same as those of the TESI-2, TESI-3, and TESI-4, respectively. The order of priority is P2 > P3 > P4.

Figure 9 is a schematic diagram of the protection implementation structure when the working entity fails and there is no idle protection entity. As shown in Figure 9, the working entity fails, and the endpoint bridge 1 detects the fault first. It checks the backup port in its own protection group. Since no idle backup port is found, Endpoint Bridge 1 checks the priority of the backup port and finds that the P4 backup port has the lowest priority and Endpoint Bridge 1 selects the P4 port. Endpoint Bridge 1 modifies its own forwarding table and changes the outgoing port of the forwarding entry corresponding to TESI-1 ( <X, 1> ) from P1 to P4. At the same time, the endpoint bridge 1 sends a switching notification message on the protection entity 3 (the message can be implemented by using the RDI field in the CCM message, but is not limited to this method), and the endpoint bridge 2 receives the switching notification message after the protection entity 2 receives the switching notification message. Modify its own forwarding table and change the outgoing port of the forwarding entry corresponding to TESI-U <Y, 2> to P4 from 14.

The segment protection scheme of the present invention can achieve fast protection for TESI, enhance the robustness of the ΡΒΒ-ΤΕ network, and improve network performance.

10 is a schematic structural diagram of a protection device for an Ethernet tunnel according to the present invention. As shown in FIG. 10, the protection device for the Ethernet tunnel of the present invention includes a setting unit 1001, a detecting unit 1002, and a switching unit 1003, wherein the setting unit 1001 is used for Setting one or more protection entities for one working entity in the Ethernet protection domain, where the working entity and the protection entity have the same two endpoint bridges; the detecting unit 1002 is configured to detect whether the working entity is faulty or not. The switching unit 1003 is triggered; the switching unit 1003 is configured to switch the protected tunnel on the working entity to a protection entity. As shown in FIG. 10, the switching unit 1003 of the present invention further includes a determining unit 10030, a selecting unit 10031, a modifying unit 10032, and a notifying unit 10033, wherein the determining unit 10030 is configured to determine whether there is an idle protection entity, and when present, the selecting unit 10031 is triggered. The selecting unit 10031 is configured to select the idle protection entity with the smallest port label as the protection entity to be switched; the modifying unit 10032 is configured to modify the outgoing port of the forwarding entry of the protected tunnel associated with the port of the working entity to be selected. The port of the protection entity; the notification unit 10033 is used to notify another The endpoint bridge performs port switching.

Wherein, the determining unit 10030 determines that there is no idle protection entity, triggering the selection unit

10031: The protection entity with the lowest priority is selected as the protection entity to be switched, and the modification unit 10032 modifies the egress port of the forwarding entry of the protected tunnel associated with the port of the working entity to the port of the selected protection entity, The notification unit notifies another endpoint bridge to perform port switching.

When the detecting unit 1002 detects that the working entity failure has disappeared, the triggering modification unit 10032 modifies the outgoing port of the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located to the port of the working entity.

The notifying unit 10033 notifies another endpoint bridge by modifying the port of the egress port that forwards the entry, and the other endpoint bridge receives the notification of port switching through the corresponding port in the other endpoint bridge by the protection entity in which the egress port is located.

As shown in FIG. 10, the protection apparatus of the Ethernet tunnel of the present invention further includes a receiving unit 1004, configured to receive the notification of the switching, and trigger the forwarding unit 10032 to forward the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located. The outbound port is modified to the port that received the notification of the switchover.

It should be understood by those skilled in the art that the protection device of the Ethernet tunnel shown in FIG. 10 is provided to implement the foregoing protection method of the Ethernet tunnel, and the functions of the processing units in the apparatus shown in FIG. 10 can refer to the foregoing method. It is described and understood that the functions of the various processing units may be implemented by a program running on a processor or by a specific logic circuit.

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

Claims

Claim

A method for protecting an Ethernet tunnel, characterized in that: one or more protection entities are set for one working entity in an Ethernet protection domain, and the working entity and the protection entity have the same two endpoint bridges; The methods include:

When the endpoint bridge detects that the working entity is faulty, the protected tunnel on the working entity is switched to a protection entity.

2. The method according to claim 1, wherein the switching the protected tunnel on the working entity to a protection entity comprises:

One of the one or more protection entities is selected as the protection entity to be switched, and the egress port of the forwarding entry of the protected tunnel associated with the port of the working entity is modified to the port of the selected protection entity.

The method according to claim 2, wherein the switching the protected tunnel on the working entity to a protection entity comprises: selecting the port label when the endpoint bridge determines that there is an idle protection entity The smallest idle protection entity, as a protection entity that is switched over, modifies the egress port of the forwarding entry of the protected tunnel associated with the port of the working entity to the port of the selected protection entity, and notifies the other endpoint bridge to perform the port Switched.

The method according to claim 2, wherein the switching the protected tunnel on the working entity to a protection entity comprises: when the endpoint bridge determines that there is no idle protection entity, the method is selected The protection entity with the lowest priority is the protection entity that is switched over, and the egress port of the forwarding entry of the protected tunnel associated with the port of the working entity is modified to the port of the selected protection entity, and the other endpoint is notified. The bridge performs port switching.

The method according to any one of claims 1 to 4, wherein the method further comprises:

When the endpoint bridge detects that the working entity fails, the egress port of the forwarding entry of the protected tunnel associated with the port of the protection entity where the current service is located is modified to be the working entity. Port.

The method according to claim 5, wherein the notifying another endpoint bridge to perform port switching comprises:

The method according to claim 6, wherein the method further comprises: after receiving the notification of the switching, the another endpoint bridge associates the protected tunnel of the port of the protection entity where the current service is located The outgoing port of the forwarding entry is modified to the port that received the notification of the switching.

A protection device for an Ethernet tunnel, comprising: a setting unit, a detecting unit and a switching unit; wherein:

The detecting unit is configured to detect whether the working entity is faulty, and trigger a switching unit when the fault occurs; and the switching unit is configured to switch the protected tunnel on the working entity to a protection entity.

9. The apparatus according to claim 8, wherein the switching unit comprises a determining unit, a selecting unit, a modifying unit, and a notifying unit; wherein:

10. The apparatus according to claim 9, wherein the determining unit determines not to When there is an idle protection entity, the selection unit is triggered to select the protection entity with the lowest priority as the protection entity to be switched, and the modification unit will output the forwarding entry of the protected tunnel associated with the port of the working entity. The port is modified to be the port of the selected protected entity, and the notification unit notifies the other endpoint bridge to perform port switching.

The device according to claim 9, wherein the detecting unit detects that the working entity fails, and triggers the modified unit to associate the protected tunnel associated with the port of the protection entity where the current service is located. The outgoing port of the forwarding entry is modified to be the port of the working entity.

12. The apparatus according to claim 10 or 11, wherein the notification unit notifies another endpoint bridge by modifying a port that is an outgoing port of the forwarding entry, and the other endpoint bridge passes the protection entity where the outgoing port is located. A corresponding port in another endpoint bridge receives notification of port switching.

The device according to claim 12, wherein the device further comprises: a receiving unit, configured to receive a notification of the switching, and trigger the modifying unit to protect the port of the protection entity where the current service is located The outbound port of the forwarding entry of the tunnel is modified to the port that received the notification of the switchover.