CN106559234B

CN106559234B - Control message sending method and device

Info

Publication number: CN106559234B
Application number: CN201510626594.1A
Authority: CN
Inventors: 杨学成
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2015-09-28
Filing date: 2015-09-28
Publication date: 2021-02-19
Anticipated expiration: 2035-09-28
Also published as: WO2017054532A1; CN106559234A

Abstract

The invention provides a control message sending method and a control message sending device, wherein the method comprises the following steps: the method comprises the steps that a first network side edge device PE receives a first control message from a second PE, wherein the first control message is used for setting the state of a physical port of a first access circuit AC connected with the first PE to be a preset state; and the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC connected with the second PE. The invention solves the problem of deadlock of end-to-end fault transmission in the related technology, thereby achieving the effect of avoiding deadlock of end-to-end fault transmission.

Description

Control message sending method and device

Technical Field

The present invention relates to the field of communications, and in particular, to a method and an apparatus for sending a control message.

Background

In order to meet the trend of metropolitan area network service transformation and three-network convergence, network operators tend to adopt a high-efficiency and low-cost packet transport network to realize multi-service bearing, provide flexible network service, improve the utilization rate of network resources, reduce the complexity of network deployment, enhance the flexibility of network service, and bring more economic benefits for the network operators.

A Layer 2Virtual Private Network (L2 VPN) is a technology for establishing a Private data communication Network in a public Network by means of an Internet service provider and a Network service provider. The Virtual Private local area network Service (VPLS) and Virtual Private network Service (VLL) can be divided into two Service models, wherein the two Service models are Ethernet Service forwarding based and point-to-multipoint network deployment is supported; the latter is a virtual private line service, and only supports Point-to-Point network deployment based on two-layer service simulation such as ethernet, Asynchronous Transfer Mode (ATM for short), Time Division multiplexing (TDM for short), High Level Data Link Control (HDLC for short), Frame Relay (FR for short), Point-to-Point Protocol (PPP for short), and the like.

Due to the high reliability requirement of the carrier-grade ethernet, the service convergence speed of the network when a fault occurs is very important for operators, which needs to pay more attention to the fault response and protection switching capability when the network is deployed, and the technologies of pseudo wire operation, management and maintenance Message Mapping (PW OAM Message Mapping) and pseudo wire redundancy backup (backup PW redundancy) proposed by the PWE3 working group of the Internet Engineering Task Force (IETF) organization are considered for this purpose.

PW OAM Message Mapping (draft-ietf-pwe3-OAM-msg-map-12) is a pseudo-wire fault notification technique. When a point-to-point simulation service is carried out, the fault mapping between an Access Circuit (AC for short) and a Pseudo Wire (PW for short) is supported, namely when the AC fails, the linkage with Operation Administration and Maintenance (OAM for short) of a PW layer is realized, the fault is notified to a far end through a PWE3 protocol message, and the far end can quickly know that the service path has failed and carry out corresponding subsequent processing.

Link Status Transfer (LST) is a Fault detection technology, and when VLL is configured end-to-end, and Fault detection mechanisms such as Connectivity Fault Management (CFM)/last kilometer (Ethernet in the First Mile, EFM) are not supported between network-side Edge devices (Provider Edge, PE) and client Edge devices (CE), LST function may be used to power down a direct connection physical interface between PE and CE, and the direct connection port of CE device may sense the Fault and complete Fault delivery.

Fig. 1 is a schematic view of a VLL end-to-end network deployment in the related art, and as shown in fig. 1, PE1 deploys VLLs, access AC1 and PW 12; PE2 deploys the VLL, accesses AC2 and PW21, forming a VLL end-to-end networking. PE1 and PE2 deploy OAM MAPPING functions and LST functions, respectively. The AC faults can be transmitted to the opposite terminal through PW.

After detecting that the AC1 has a fault on the PE1, the OAMMAPPING function transmits the fault to the PE2 through a PWE3 protocol;

the LST function receives 'AC 1 fault information' transmitted by a PWE3 protocol on the PE2 and transmits the 'AC 1 fault information' to the AC2, a physical interface of the AC2 is set to be down, and CE2 equipment directly connected with the AC2 can sense the down operation of the interface and carry out fault processing on some services.

The symmetric networking scene has a problem:

PE1 and PE2 are symmetrically networked, both oamapping and LST are turned on.

When the AC1 and the AC2 simultaneously fail (such as fiber pulling operation), after the PE1 and the PE2 respectively detect, OAMMAPPING/DOWN are mutually transmitted to the opposite side through the PWE 3;

after receiving OAMMAPPING/DOWN, PE1 transmits the fault to AC1 through LST function, and sets AC1 physical port DOWN;

meanwhile, after receiving OAMMAPPING/DOWN, PE2 transmits the fault to AC2 through LST function, and sets AC2 physical port DOWN;

when the AC1 fault is recovered (such as fiber plugging operation), the fiber plugging operation cannot recover the AC1 state and cannot send OAMMAPPING/UP to the PE2 because the LST function caused by OAMMAPING/DOWN transmitted by the far end before the AC1 is put through physical DOWN.

Similarly, when the AC2 fault is recovered (e.g., a fiber plugging operation), the fiber plugging operation cannot recover the AC2 state and cannot send OAMMAPPING/UP to the PE1 because the LST function caused by oammping/DOWN previously transmitted by the AC2 from the remote end is put DOWN physically.

Therefore, the interfaces at two ends cannot be powered up, and the states at two ends are deadlocked. Therefore, there may be a deadlock problem of end-to-end fault delivery in the related art.

An effective solution is not provided at present for the deadlock problem of end-to-end fault delivery existing in the related art.

Disclosure of Invention

The invention provides a control message sending method and a control message sending device, which are used for at least solving the problem of deadlock of end-to-end fault delivery in the related technology.

According to an aspect of the present invention, there is provided a control message transmitting method, including: a first network side edge device PE receives a first control message from a second PE, wherein the first control message is used for setting the state of a physical port of a first access circuit AC connected with the first PE to be a preset state; and the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC connected with the second PE.

Optionally, the sending, by the first PE, the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes: and when the predetermined state is a power-down state and the actual state of the physical port of the first AC is a power-down state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be a power-up state.

Optionally, the sending, by the first PE, the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes: and when the predetermined state is a power-on up state and the actual state of the physical port of the first AC is a power-off down state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be down.

Optionally, the sending, by the first PE, the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes: and when the predetermined state is a power-on up state and the actual state of the physical port of the first AC is an up state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be up.

Optionally, before receiving the first control message from the second PE, the first PE further includes: the first PE receives a fault message transmitted by the first AC, wherein the fault message is used for identifying that the first AC fails; and the first PE sends a third control message to the second PE according to the fault message, wherein the third control message is used for controlling the state of a physical port of the second AC to be powered down.

According to another aspect of the present invention, there is provided a control message sending apparatus, which is applied in a first network-side edge device PE, and includes: a first receiving module, configured to receive a first control message from a second PE, where the first control message is used to set a state of a physical port of a first access circuit AC connected to the first PE to a predetermined state; a first sending module, configured to send a second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, where the second control message is used to control a state of a physical port of a second AC connected to the second PE.

Optionally, the first sending module comprises: and when the predetermined state is a power-down state and the actual state of the physical port of the first AC is a power-down state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be a power-up state.

Optionally, the first sending module comprises: and when the predetermined state is a power-on up state and the actual state of the physical port of the first AC is a power-off down state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be down.

Optionally, the first sending module comprises: and when the predetermined state is a power-on up state and the actual state of the physical port of the first AC is an up state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be up.

Optionally, the apparatus further comprises: a second receiving module, configured to receive a failure message delivered by the first AC before receiving the first control message from the second PE, where the failure message is used to identify that the first AC has failed; and a second sending module, configured to send a third control message to the second PE according to the fault message, where the third control message is used to control a state of a physical port of the second AC to be powered down.

According to the invention, a first network side edge device PE is adopted to receive a first control message from a second PE, wherein the first control message is used for setting the state of a physical port of a first access circuit AC connected with the first PE to be a preset state; and the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC connected with the second PE, so that the problem of deadlock of end-to-end fault transmission in the related technology is solved, and the effect of avoiding the deadlock of end-to-end fault transmission is achieved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a schematic view of VLL end-to-end network deployment in the related art;

fig. 2 is a flowchart of a control message transmission method according to an embodiment of the present invention;

fig. 3 is a block diagram of a structure of a control message transmission apparatus according to an embodiment of the present invention;

fig. 4 is a block diagram of a preferred structure of a control message transmission apparatus according to an embodiment of the present invention;

FIG. 5 is a scene topology diagram of an end-to-end networking OAMMAPPING according to an embodiment of the invention;

fig. 6 is a block diagram exchange according to an embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

In this embodiment, a control message sending method is provided, and fig. 2 is a flowchart of a control message sending method according to an embodiment of the present invention, as shown in fig. 2, the flowchart includes the following steps:

step S202, a first network-side edge device PE receives a first control message from a second PE, where the first control message is used to set a state of a physical port of a first access circuit AC connected to the first PE to a predetermined state;

step S204, the first PE sends a second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, where the second control message is used to control the state of the physical port of the second AC connected to the second PE.

Through the steps, after receiving the first control message sent by the second PE, the first PE sends the control message to the second PE according to the state of the physical port of the first AC controlled by the first control message and the actual state of the physical port of the first AC, so that the problem of deadlock of end-to-end fault delivery in the related art is solved, and the effect of avoiding deadlock of end-to-end fault delivery is achieved.

In an optional embodiment, the sending, by the first PE, the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes: and when the preset state is a power-down state and the actual state of the physical port of the first AC is a down state, the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be a power-up. When the actual state of the physical port of the first AC is a down state, the first AC sends a control message for controlling the state of the physical port of the second AC to be down to the second PE, and after the second AC fails, the first PE receives the first control message sent by the second PE.

In an optional embodiment, the sending, by the first PE, the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes: and when the preset state is a control message of power-on up and the actual state of the physical port of the first AC is a power-off down state, the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be down.

In an optional embodiment, the sending, by the first PE, the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes: and when the predetermined state is a control message of power-on up and the actual state of the physical port of the first AC is the up state, the first PE sends a second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be up.

In an alternative embodiment, the first PE, before receiving the first control message from the second PE, further comprises: the first PE receives a fault message transmitted by the first AC, wherein the fault message is used for identifying that the first AC fails; and the first PE sends a third control message to the second PE according to the fault message, wherein the third control message is used for controlling the state of the physical port of the second AC to be powered down.

Through the above description of the embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but the former is a better implementation mode in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (e.g., ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (e.g., a mobile phone, a computer, a server, or a network device) to execute the method according to the embodiments of the present invention.

In this embodiment, a control message sending apparatus is further provided, and the apparatus is used to implement the foregoing embodiments and preferred embodiments, and details of which have been already described are omitted. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 3 is a block diagram of a control message sending apparatus according to an embodiment of the present invention, which may be applied to a first network edge device PE, and as shown in fig. 3, the apparatus includes a first receiving module 32 and a first sending module 34, which will be described below.

A first receiving module 32, configured to receive a first control message from a second PE, where the first control message is used to set a state of a physical port of a first access circuit AC connected to the first PE to a predetermined state; and a first sending module 34, connected to the first receiving module 32, configured to send a second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, where the second control message is used to control the state of the physical port of the second AC connected to the second PE.

Optionally, the first sending module 34 includes: and when the preset state is a power-down state and the actual state of the physical port of the first AC is a down state, the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be a power-up.

Optionally, the first sending module 34 includes: and when the preset state is a power-on up state and the actual state of the physical port of the first AC is a power-off down state, the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be down.

Optionally, the first sending module 34 includes: and when the preset state is a power-on up state and the actual state of the physical port of the first AC is an up state, the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be up.

Fig. 4 is a block diagram of a preferred structure of a control message transmission apparatus according to an embodiment of the present invention, which includes a second receiving module 42 and a second transmitting module 44 in addition to all the modules shown in fig. 3, and the apparatus will be described below.

A second receiving module 42, configured to receive a failure message delivered by the first AC before receiving the first control message from the second PE, where the failure message is used to identify that the first AC fails; and a second sending module 44, connected to the second receiving module 42 and the first receiving module 32, configured to send a third control message to the second PE according to the failure message, where the third control message is used to control the state of the physical port of the second AC to be powered down.

The invention is described below with reference to specific application scenarios:

the embodiment of the invention provides a fault transmission technology of a virtual private network, which solves the deadlock problem of end-to-end fault transmission through the control of a state machine.

Fig. 5 is a scene topology diagram of an end-to-end networking oammaping according to an embodiment of the present invention, fig. 6 is a module switching diagram according to an embodiment of the present invention, and the following description is provided with respect to the PE1 device in fig. 5 and fig. 6. In an embodiment of the present invention, a switching system is provided, where a PE mainly includes: PWE3 protocol module 62 (like the first and second transmitting modules 34, 44 described above), LST module 64, first interface module 66, and failure detection module 68 (like the second receiving module 42 described above), CE includes a second interface module 610, wherein,

PWE3 protocol module 62: the method mainly realizes sending and receiving OAMMAPPING/down and OAMMAPPING/up messages according to the detected state of the physical port of the AC 1;

the LST module 64: the method mainly realizes that the LST down/up state is transmitted to an interface module of the AC1 according to OAMMAPPING/down and OAMMAPPING/up messages received by a PWE3 protocol module;

the first interface module 66: the method mainly realizes the operation of the physical port down/up according to the LST down/up state, and achieves the effect of fiber breaking/fiber inserting;

the fault detection module 68: mainly for detecting link failures of the AC.

The second interface module 610: mainly used for sensing the state of the physical interface of the AC1, so that the CE executes corresponding operation according to the state of the physical interface of the AC 1.

In the following embodiments, oammping down corresponds to OAMMAPPING down, and oamapping up corresponds to OAMMAPPING up.

With reference to fig. 5, a networking application scenario is introduced first, and then the implementation steps of the present invention are described in detail.

The embodiment of the invention comprises the following steps:

step A, the VLL end-to-end network deployment is carried out, and the step A specifically comprises the following steps:

a1, PE1 establishes VLL service, and configures AC1 and PW 12;

PE2 establishes VLL service, and configures AC2 and PW 21;

after step a is completed, VLL end-to-end network deployment is completed. The PW state established between PE1 and PE2 is normal, and the flow can be normal.

B, respectively starting OAMMAPPING and LST functions by PE1 and PE 2; the step B specifically comprises the following steps:

PW12 on PE1 turns on OAMMAPPING function, and LST function on AC 1;

PW21 on PE2 turns on OAMMAPPING function, and LST function on AC 2;

after step B is completed, after the AC1 fails, the AC1 can be transmitted to the PE2 through OAMMAPPING function; after the AC2 fails, it can be passed to PE1 via oamapping functionality. After receiving the oammping down message, PE1 and PE2 may set the physical interfaces of AC1 and AC2 down.

When the AC1 link fails, the fault detection module detects the AC1 fault, informs the PWE3 signaling module, and sends the OAMMAPPING down message to the opposite end PE 2;

when the AC2 link fails, the fault detection module detects the AC2 fault, informs the PWE3 signaling module, and sends the OAMMAPPING down message to the opposite end PE 1;

to this end, both AC1 and AC2 associated with PE1 and PE2 failed. The two ends send OAMMAPPING down message to the opposite end.

Step E, after receiving OAMMAPPING down message, the PWE3 signaling module of PE1 informs the LST module, and at this time, performs distinguishing processing according to the interface state + LST state, as shown in Table 1:

TABLE 1

Interface status	DOWN
		LST state	DOWN
Processing logic	Sending OAMMAPPING up to the opposite end

At this time, the interface state and the LST state are both DOWN, oammapping up is sent to PE2, and the previously sent fault is cleared.

After receiving OAMMAPPING up, PE2 informs the LST module, and at this time, the difference processing is carried out according to the interface state and the LST state, as shown in the table 2:

TABLE 2

Interface shapeState of the art	DOWN
		LST state	UP

Processing logic

Sending oammapping down to the opposite end

At this time, both AC1 and AC2 associated with PE1 and PE2 failed. PE1 sends oammping up to PE2, and PE2 sends oamapping down to PE 1.

The method comprises the following steps that (1) AC2 fault recovery is carried out, a fault detection module detects AC2 fault recovery, informs a PWE3 signaling module, and sends OAMMAPPING up message to an opposite terminal PE 1;

after receiving the oamapping up message, the "PWE 3 signaling module" of the step h.pe1 notifies the "LST module", and at this time, performs distinction processing according to the "interface state + LST state", as shown in table 3:

TABLE 3

Interface status	DOWN
		LST state	UP
Processing logic	Sending oammapping down to the opposite end

At this time, AC1 is in fault state, AC2 is in normal state, PE1 sends oamapping down to PE2, and PE2 sends oamapping up to PE 1.

The method comprises the steps that (1) AC1 fault recovery is carried out, a fault detection module detects AC1 fault recovery, informs a PWE3 signaling module and sends OAMMAPPING up messages to opposite end PE 2;

after receiving the oamtping up message, the PWE3 signaling module of the pe2 notifies the LST module, and performs distinction processing according to the interface state + LST state, as shown in table 4:

TABLE 4

Interface status	UP
		LST state	UP
Processing logic	Sending oammapping up to opposite terminal

At this time, the AC1 is in a normal state, the AC2 is in a normal state, the PE1 sends oammping up to the PE2, and the PE2 sends oammping up to the PE1, so that deadlock does not occur at two ends.

Compared with the related art, when VLL is symmetrically networked end to end, the problem of state deadlock exists when faults at two ends are mutually transmitted. The invention provides a state control method, which separates the state of a local terminal from the state of a remote terminal through the control of a state machine in the process of fault transmission and solves the problem of deadlock of the network. The mechanism is completely realized based on the existing hardware of the equipment, only needs to provide technical support of a software control layer, and is easy to implement.

It should be noted that, the above modules may be implemented by software or hardware, and for the latter, the following may be implemented, but not limited to: the modules are all positioned in the same processor; alternatively, the modules are respectively located in a plurality of processors.

The embodiment of the invention also provides a storage medium. Alternatively, in the present embodiment, the storage medium may be configured to store program codes for performing the following steps:

s1, the first PE receives a first control message from the second PE, where the first control message is used to set the state of the physical port of the first access circuit AC connected to the first PE to a predetermined state;

s2, the first PE sends a second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, where the second control message is used to control the state of the physical port of the second AC connected to the second PE.

Optionally, in this embodiment, the storage medium may include, but is not limited to: various media capable of storing program codes, such as a usb disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic disk, or an optical disk.

Alternatively, in the present embodiment, the processor performs the above-mentioned steps S1-S2 according to program codes already stored in the storage medium.

Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation manners, and this embodiment is not described herein again.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for transmitting a control message, comprising:

a first network side edge device PE receives a first control message from a second PE, wherein the first control message is used for setting the state of a physical port of a first access circuit AC connected with the first PE to be a preset state;

the first PE sends a second control message to the second PE according to the preset state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC connected with the second PE;

the sending, by the first PE, a second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC includes:

and when the predetermined state is a power-down state and the actual state of the physical port of the first AC is a power-down state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be a power-up state.

2. The method of claim 1, wherein sending, by the first PE, a second control message to the second PE according to the predetermined status and an actual status of a physical port of the first AC further comprises:

and when the predetermined state is a power-on up state and the actual state of the physical port of the first AC is a power-off down state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be down.

3. The method of claim 1, wherein sending, by the first PE, a second control message to the second PE according to the predetermined status and an actual status of a physical port of the first AC further comprises:

and when the predetermined state is a power-on up state and the actual state of the physical port of the first AC is an up state, the first PE sends the second control message to the second PE according to the predetermined state and the actual state of the physical port of the first AC, wherein the second control message is used for controlling the state of the physical port of the second AC to be up.

4. The method of any of claims 1-3, wherein the first PE, prior to receiving the first control message from the second PE, further comprises:

the first PE receives a fault message transmitted by the first AC, wherein the fault message is used for identifying that the first AC fails;

and the first PE sends a third control message to the second PE according to the fault message, wherein the third control message is used for controlling the state of a physical port of the second AC to be powered down.

5. A control message transmission apparatus, for use in a first network-side edge device PE, comprising:

a first receiving module, configured to receive a first control message from a second PE, where the first control message is used to set a state of a physical port of a first access circuit AC connected to the first PE to a predetermined state;

a first sending module, configured to send a second control message to the second PE according to the predetermined state and an actual state of a physical port of the first AC, where the second control message is used to control a state of a physical port of a second AC connected to the second PE;

the first transmitting module includes:

6. The apparatus of claim 5, wherein the first sending module further comprises:

7. The apparatus of claim 5, wherein the first sending module further comprises:

8. The apparatus of any of claims 5 to 7, further comprising:

a second receiving module, configured to receive a failure message delivered by the first AC before receiving the first control message from the second PE, where the failure message is used to identify that the first AC has failed;

and a second sending module, configured to send a third control message to the second PE according to the fault message, where the third control message is used to control a state of a physical port of the second AC to be powered down.