CN112202634B

CN112202634B - Network link fault detection and transmission method and system

Info

Publication number: CN112202634B
Application number: CN202011019128.4A
Authority: CN
Inventors: 康庄; 刘振华; 刘刘
Original assignee: Fiberhome Telecommunication Technologies Co Ltd
Current assignee: Fiberhome Telecommunication Technologies Co Ltd
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2022-04-15
Anticipated expiration: 2040-09-23
Also published as: CN112202634A

Abstract

The invention discloses a method and a system for detecting and transmitting network link faults, which relate to the technical field of communication, and the method comprises the steps that edge servers of a first link and a second link are respectively connected with each other through a virtual private network, and the first link and the second link respectively comprise a front-end device and an edge router; two edge servers send first state messages to each other, and two edge routers send second state messages to each other; if the link is abnormal, sending a state message with a fault alarm, and configuring a port of a user side of the user side as an alarm state; if the received state message has a fault alarm, configuring a port of a user side of the user side as an alarm state; the front-end device detects the alarm state of the port of the user side of the edge router of the same link and judges the fault position of the link according to the receiving states of the first state message and the second state message. The invention can quickly detect the link fault position in the network and improve the efficiency of positioning the link fault.

Description

Network link fault detection and transmission method and system

Technical Field

The invention relates to the technical field of communication, in particular to a method and a system for detecting and transmitting network link faults.

Background

Since birth, ethernet technology gradually becomes the leading technology of local area networks due to its characteristics of simplicity, easy use, low price, etc. In recent years, with the successive application of gigabit ethernet technology, ethernet has expanded towards metropolitan area networks and wide area networks.

A Virtual Private Network (VPN) is a technology for establishing a Private Network on a public Network. With the explosion of the internet, the technology of the virtual private network is developed rapidly, and the application is more and more extensive. In carrier-level or enterprise-level networks, accessing a VPN by a client device via ethernet is a typical and common networking approach. Although ethernet CFM can implement end-to-end connectivity detection and fault management within a maintenance domain in networking, problems remain to be solved.

Most typically, a client device is connected to a client edge router, then connected to a network edge server through an ethernet, and connected to an L2VPN network through the network edge server to form a network link, where an Access Circuit (AC) on the client edge router side and a Virtual Circuit (VC) on the operator edge server side are independent of each other, and do not affect each other or cannot sense the state of the other. Meanwhile, the client device as the end node cannot sense the operating state of a virtual link (PW) in the L2VPN network and the operating state of the remote AC side, which brings great difficulty to operation and maintenance.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a network link fault detection and transmission method and a network link fault transmission system, which can quickly detect the link fault position in a networking and improve the efficiency of locating the link fault.

To achieve the above object, in a first aspect, an embodiment of the present invention provides a method for detecting and transferring a network link failure, which includes:

compared with the prior art, the invention has the advantages that:

the invention relates to a method and a system for detecting and transmitting network link faults, wherein port state configurations of a first message and a second message which pass through a link and can carry fault alarms, an edge server and an edge router help a front-end device in the link to rapidly and intuitively obtain information about the two links, and accurately judge a node with a fault in the link according to the information. The fault detection mode has strong instantaneity, and ensures that the perception states of all equipment in the link to the fault can be quickly unified.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings corresponding to the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a network according to an embodiment of a method and system for detecting and transmitting a network link failure;

FIG. 2 is a flow chart of a method for detecting and communicating network link failures according to an embodiment of the present invention;

FIG. 3 is a flow chart of another embodiment of a method for detecting and communicating network link failures in accordance with the present invention;

fig. 4 is a schematic structural diagram of a CCM frame according to an embodiment of a method for detecting and transmitting a network link failure.

Detailed Description

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

The embodiment of the invention provides a method and a system for detecting and transmitting network link faults.

In order to achieve the technical effects, the general idea of the application is as follows:

the edge servers of a first link and a second link are respectively connected with each other through a virtual private network, and the first link and the second link respectively comprise a front-end device and an edge router;

the two edge servers mutually send first state messages, and the two edge routers mutually send second state messages;

and judging the abnormal position of the link according to the receiving states of the first state message and the second state message and whether the first state message and the second state message carry far-end fault information.

To sum up, the devices on the first link and the second link are connected in sequence: the system comprises a front-end device, an edge router, an edge server, another edge router and another front-end device, wherein the two edge servers are connected through a virtual private network, and the edge servers of the same link are connected with the edge router through Ethernet.

On the first link and the second link, the network related to the first state message is the link between the two edge servers and the link between the two edge servers, and the network related to the second state message is the link between the two edge servers and the two edge routers, and through the two state messages, the fault information can be ensured to be sequentially fed back to the related equipment and the link.

Furthermore, the two status messages can also carry fault alarms, notify the fault of the other link, and simultaneously distinguish which link of the two links has the fault, so that the status of a single device and the link can be accurately reflected finally.

Therefore, the final front-end device, according to the received information: the receiving states of the first state message and the second state message, whether the first state message and the second state message carry fault alarms or not and the state of the edge router port are judged accurately and quickly according to the node where the current fault occurs.

In order to better understand the technical solution, the following detailed description is made with reference to specific embodiments.

Referring to fig. 1, an embodiment of the present invention provides a method for detecting and transmitting a network link failure, including:

s1: the edge servers of the first link and the second link are respectively connected with each other through a virtual private network, and the first link and the second link respectively comprise a front-end device and an edge router.

Specifically, the first link and the second link each include an edge server, an edge router, and a front-end device, and when the first link and the second link are connected through the virtual private network, the connection order of each device is as follows: the edge server of the first link is connected with the edge server of the second link through a virtual private network, the edge server of the first link is connected with the edge router of the first link through an Ethernet, and the edge server of the second link is connected with the edge router of the second link through the Ethernet.

For example: as shown in fig. 2, a first customer needs to communicate or service with a second customer, a front-end device CPE1 of the first customer accesses an edge router CE1, the edge router accesses an edge server PE1 of a first operator, the edge server PE1 of the first operator establishes a virtual private network with an edge server PE2 of the second operator and completes connection, the edge server PE2 of the second operator connects with an edge router CE2 of the second customer, and the edge router CE2 of the second customer finally completes connection with a front-end device of a second account.

The invention also provides an embodiment:

the CPE1 is connected to an a interface of an edge router of a first operator, a B interface of the edge router of the first operator is connected to a C interface of an edge server of the first operator via an ethernet, a D interface of the edge server of the first operator is connected to an E interface of an edge server of a second operator via a private network, an F interface of the edge server of the second operator is connected to a G interface of an edge router of the second operator via an ethernet, and an H interface of the edge router of the second operator is connected to a CPE of a second customer.

S2: the two edge servers mutually send first state messages, and the two edge routers mutually send second state messages;

the first status message and the second status message ensure the status information intercommunication of the two links. After the first link and the second link are connected through the virtual private network, the two links are mutually independent and cannot be sensed, and the invention establishes two mechanisms for mutually sending messages: the two edge servers mutually send first state messages, and the two routers mutually send second state routes, so that the two links can provide link state information for each device through the messages.

Specifically, connectivity fault management maintenance end points MEPs are configured on two edge servers, a link between the two MEPs is used as a first maintenance domain CFM1, the two MEPs send a first state message to each other in a CFM1, the connectivity fault management maintenance end points MEPs are configured on two edge routers, the link between the two MEPs is used as a second maintenance domain CFM2, and the two MEPs send a second state message to each other in a CFM 2. It should be noted that, the CFM is a Connectivity Fault Management module (CFM) based on standard protocol (IEEE 802.1ag, ITU-T y.1731) ethernet, which is proposed to effectively improve the Management and maintenance capability of the ethernet and ensure the stable operation of the network. Meanwhile, in the technology of network-level ethernet OAM (Operation Administration and Maintenance), the ethernet CFM is mostly applied to an access convergence layer of a network, and is used for monitoring the connectivity of the entire network, locating connectivity faults of the network, and implementing functions such as end-to-end monitoring, management, diagnosis and performance detection.

It should be further noted that, the first status packet or the second status packet is used as a packet, which can achieve the effect of reflecting the status of the inter-sending packet path link, and the technical solutions that can achieve the effect are included in the step.

In an optional embodiment, the first status packet or the second status packet with the fault alarm includes a first status packet or a second status packet inserted with port status exception information.

Further, a data bit is set in the first status message or the second status message, and is used for describing a fault notification of a far-end link that the link is on or off, respectively, after the other end receives the message, it can be determined that the far-end link has a fault through the data bit, and further, a fault position is preliminarily determined through a difference that the first message and the second message feed back the on or off of the link (for example, the first message does not feed back, the second link feeds back the open circuit) (and link fault warning information of equipment in the link also needs to be combined).

In another optional embodiment, the determination may also be made only according to the sending states of the first status packet and the second status packet and the actual condition of the link, if the link message is found to be obstructed, the first status packet can be sent and received at the same time, and the second status packet is sent but not received, so as to preliminarily determine the location failure of the edge server and the edge router in the first link or the second link (in addition, link failure alarm information of the device in the link needs to be combined)

Preferably, the first status message is sent in the form of a CCM frame. The two edge servers mutually send CCM frames carrying the first state message, and the two edge routers mutually send CCM frames carrying the second state message;

and the first status message and the second status message can be inserted into port status abnormal information, and the port status abnormal information is used for identifying whether the equipment sending the first status message or the second status message has a fault alarm or not.

The edge server of the first link or the second link monitors the state of a direct connection port of an edge router of the same link, and if the state is an alarm state, port state abnormal information is inserted into a sent first state message;

in the first link or the second link, the edge router monitors the state of a direct connection port of the front-end equipment of the edge router and the same link, and if the state is in an alarm state, the edge router inserts port state abnormal information into a sent second state message.

For example, two MEPs on the edge server send a first status message in the form of a CCM frame to each other in CFM1, and two MEPs on the edge router send a second status message in the form of a CMM frame to each other in CFM2, where the first status message and the second status message each include a remote failure indication bit RDI. And configuring a link which can carry far-end fault information and can assist in judging the occurrence of the fault on the first state message and the second state message. Because the first link and the second link are symmetrical in structure, and both can receive and transmit the first status message and the second status message, the symmetrical structure causes that it is difficult to judge which link fails according to the message. After the first status message and the second status message carry the far-end fault information, the party receiving the far-end fault information can easily know that the link of the opposite end has a fault.

When the equipment finds the link fault, the far-end fault indication bit is set to be true, and a first state message or a second state message corresponding to the equipment is sent to the opposite-end link, so that the fault of which link is specifically confirmed by one party sending and one party receiving the far-end fault indication, and the fault sending position is pushed out according to the rule of sending the far-end fault indication by the message.

Preferably, the rule for sending the far-end fault indication by the message is that when the upper-level device and the lower-level device are in link fault, the message corresponding to the upper-level device sets the far-end fault indication position and sends the far-end fault indication position to the opposite-end link.

In a specific embodiment, after a link failure occurs between PE1 and CE1, the first status packet between PE1 and PE2 can be normally received and transmitted, and the second status packet between CE1 and CE2 cannot be normally received and transmitted. And both PE1 and CE1 detect a link failure, PE1 sets the RDI of the first state packet and sends it to PE2, and since the first state packet can be normally received and sent, PE2 can receive the first state packet sent by PE1 and find that its RDI is set.

In an optional embodiment, the edge server and the edge router determine whether to send a link failure alarm according to the transceiving state of the second message of the first message, and determine the location of the link failure through the link failure alarms of different devices and the RDI.

Further, in an optional embodiment, it is necessary to determine a fault location by combining a link fault alarm sent by an edge server and an edge router, and a link fault alarm bit carried by a first state message and a second state message, so that before this, if the first link or the second link has a fault, the edge server and the edge router send a link fault alarm, and link fault alarm information is inserted into the sent first state message or the sent second state message.

For example, when an ethernet connection between CE1 and PE1 or between CE2 and PE2 fails in a link:

firstly, because the second state message can not be smoothly received and sent, the MEP which is positioned in the CMF2 and on the edge router can generate a link fault alarm;

due to communication blockage with PE1 or PE2, a link fault occurs in CE1 or CE2, the state of a port A or H is set to be abnormal, and CPE1 or CPE2 equipment link fault is informed through the abnormal state of the port;

thirdly, since the PE1 or PE2 device can also check the status abnormality of the interface C side or interface F side, it notifies the opposite PE device of the AC side port abnormality of the home terminal through the RDI of the MEP located in the CMF1, and the opposite PE device can notify the front-end device step by step because the communication is normal.

It should be noted that, a CCM frame in the present invention refers to a Continuity Check Message (CCM) used for detecting and maintaining connectivity between Entity Group End points (MEPs), and actually plays a role of an ethernet CFM connectivity detection Message, that is, the CCM frame can be used as a first status Message and a second status Message that are sent to each other in the present invention. Where MEPs are maintenance nodes within an ethernet CFM domain, the CFM is deployed between CE1 and CE2, i.e.: the CE1 and the CE2 are a pair of maintenance nodes (MEPs) in a CFM maintenance domain, and the MEPs periodically transmit a connectivity check message (CCM frame) and receive a CCM message transmitted by an opposite MEP.

S3: if the edge server and/or the edge router finds that the link is abnormal, a first state message and/or a second state message with fault alarm is sent, a port of a user side of the edge server and/or the edge router is configured to be in an alarm state, and the link abnormality comprises the received first state message and/or the received second state message abnormality and the port of the user side directly connected with the link abnormality is in the alarm state.

When the first status message and the second status message are mutually sent and abnormal, if the first status message or the second status message cannot be received, the receiving equipment needs to transmit the information of finding the fault to the outside. Thus, the other link can confirm the fault of the fault alarm link end of the sending end through whether the first state message and/or the second state message carries the fault alarm; and the port of the user side configured with the port can prompt the equipment fault information of the section if the port is in an alarm state.

Similarly, when the port of the user side directly connected with the port is in the alarm state, the port of the user side is configured to be in the alarm state by sending the first state message and/or the second state message with the fault alarm, so as to inform the information related to the fault.

S4: and if the first state message and/or the second state message received by the edge server and/or the edge router have fault alarm, configuring a port of the user side of the edge server and/or the edge router to be in an alarm state.

Furthermore, after receiving the first status message and/or the second status message with the fault alarm, the user only needs to configure the port status of the user side without sending the fault alarm message to the other side, and the user side port transfers the relevant information of the fault step by step.

And S5, the front-end device detects the alarm state of the port of the user side of the edge router of the same link and judges the fault position of the link according to the receiving states of the first state message and the second state message.

As long as any position on the first link, the second link, and the virtual private network between the first link and the second link fails, after steps S1 to S4, any front-end device on the two links only needs to detect the alarm state of the port on the user side of the edge router of the same link, and can determine the position of the link failure according to the receiving states of the first state packet and the second state packet.

The front-end device acquires whether the link fault exists in the whole network according to the monitoring of the state of the direct connection interface between the front-end device and the edge router. According to the receiving and sending states of the messages in the link and whether the messages carry far-end fault information, the fault position of the link can be accurately judged. Meanwhile, the front-end equipment is used as judgment equipment, fault information related to the link is collected, a user can directly know the fault alarm at the position of the front-end equipment, and the method is more convenient and quicker.

Specifically, after finding a fault, the edge server adjusts the port states on the interfaces between itself and the edge router, and after finding a fault, the edge router adjusts the port states on the interfaces between itself and the front-end device, so that the edge router and the front-end device can read the port states of the connected interfaces to obtain link state information.

Taking an ethernet failure between the CE1 device and the PE1 device as an example, the MEP between the CE1 and the CE2 device generates a link failure alarm because it cannot receive the second message, that is, the CE1 and the CE2 detect the link failure, and immediately set the port state on each device to be abnormal, so that the CPE1 and the CPE2 at the ends can learn that the network between the CE devices has the link failure by detecting the port state connected to the CE devices.

Finally, the link fault alarm at the position corresponding to the MEP further informs the fault position of the current link, the link fault alarm of the link is the link fault alarm sent by the equipment when the link where the equipment is located is in fault, the fault position can be traced and judged according to the link fault alarm sending rule as long as the link fault alarm is sent according to the fault position of the link, and the position where the fault occurs at which end of the equipment to send the link fault alarm can be artificially selected, for example, when the edge server and the edge router link fault, the edge server sends the link fault alarm; when the edge router and the front-end equipment are in link failure, the edge router sends out a link failure alarm, and the current failure position can be further confirmed according to the judgment rule.

The present invention also provides an embodiment in which a first customer CPE1 accesses a first port a of a first customer edge router CE 1; between the second port B of the CE1 and the third port C of the first carrier edge server PE1 is an ethernet network; between the fourth port D of PE1 and the fifth port E of the second operator edge server PE2 is a virtual private network; the sixth port F of PE2 and the seventh port G of the second customer edge router CE2 were preceded by another segment of ethernet network; the second customer equipment CPE2 passes through the eighth port H of the first customer edge router CE 2.

Further, a connectivity fault management CFM1 is deployed on PE1 and PE2, and a CCM frame mutually transmitted by CFM1 detects a link fault between PE1 and PE2 devices; connectivity fault management CFM2 is deployed on CE1 and CE2, and CCM frames mutually transmitted through CFM2 detect a link between CE1 and CE2 devices. The maintenance domain of CFM2 contains CFM 1. The CCM frames sent by CFM1 are the first status messages, and the CCM frames sent by CFM2 are the second status messages.

Maintenance domains CFM1 and CFM2 are configured corresponding to PE1 and PE2CE1 and CE2, MEPs are configured corresponding to maintenance domains CFM1 and CFM2 on PE1, PE2, CE1 and CE2, and the MEPs mutually transmit CCM frames in corresponding CFM1 and CFM2

Specifically, when a link failure occurs in the VPN network between PE1 and PE2, CCM frames mutually sent by MEPs in CFM1 and CFM2 cannot reach the opposite end, and both the MEPs configured on CFM1 and CFM2 detect the link failure (the CCM frames cannot reach) and generate an alarm. The alarm issued by the MEP within CFM1 or CFM2 is detected by PE1 or PE 2. And immediately setting the bound port state on the respective equipment as an exception. The CE1 device can acquire the virtual link state in the vpn by detecting the state of the port connected to the PE1 device. The CE2 device can also learn the virtual link status by detecting the port status connected to the PE2 device. Similarly, when a CE device detects that an alarm of an MEP in the CFM2 is generated, a port state on a device corresponding to each MEP is immediately set to be abnormal, and a CEN device at the end can know that a link failure exists in a network between the CE devices by detecting a port state connected to the CE device. By the method, CPE, CE and PE equipment at two ends of the virtual private network can detect or acquire the virtual link state between the PE equipment in time.

When a link failure occurs in an ethernet network between a PE device and a CE device, taking the ethernet failure between the CE1 device and the PE1 device as an example, an MEP in a CFM2 between the CE devices generates an alarm, the CE devices detect the link failure, immediately set a port state on a device corresponding to each MEP to be abnormal, and a CPE device at the end can learn that the link failure occurs in the network between the CE devices by detecting the port state connected to the CE device. The CCM frame sent by the MEP of the CFM1 between the PE devices can still reach the opposite end, and no alarm is generated. When a port state abnormality can be detected on a PE1 device, when an MEP in CFM1 on PE1 sends a CCM frame, the state of its MEP bound port is inserted into the CCM frame in the form of TLV field and sent to an opposite end MEP (access circuit side port of PE2 device), and the PE2 device can learn the AC side port state of the PE1 device by analyzing the CCM frame, thereby learning the opposite end access circuit side port state. By the method, CEN, CE and PE equipment at two ends of the VPN network can detect or acquire the AC link state between the CE and the PE equipment in time.

When a link between a CE1 device and a customer equipment CPE1 fails, a port directly connected between the CE1 device and the CPE1 device (i.e., a port of a device corresponding to a home MEP) may detect a port state abnormality, and when a MEP on the CE1 transmits a CCM frame, the state of a home MEP binding port is inserted into a CCM frame in the form of a TLV field and transmitted to an opposite MEP (a direct connection port between a CE2 device and a CPE2 device), the CE2 device may analyze the CCM frame to know that a link state between the CE1 device and the CPE1 device is abnormal, and set the state of the direct connection port between the CE2 device and the CPE2 as abnormal. Thus, the CPE2 device can learn the link failure of the end-point device at the opposite end by detecting the status of the port directly connected to the CE2 device.

For example, a link between device PE1 and device PE2 configures a maintenance domain CFM1, and configures an inward MEP1 on port C of device PE1, configuring a maintenance domain and a maintenance set to which it belongs as CFM 1; another inward MEP2 is configured on port F of device PE2, MEP2 and MEP1 belong to the same maintenance domain and maintenance set CFM1, and are far-end with MEP1, and the CCM frame transmission period of MEP1 is the same as MEP 1.

On PE 1:

t1: as shown in fig. 4, MEP1 configured on PE1 mutually transmits CCM frames according to a preset period, where the CCM frames include a flag byte containing an RDI bit and an interface status TLV. The CCM frames are sent out via port D and across the VPN network to the PE2 device.

T2: PE1 receives a packet from the VPN network from port D, and when PE1 receives a CCM frame from port D, determines the maintenance domain to which it belongs: CCM frames belonging to the same maintenance domain are sent to MEP 1; low level CCM frames are discarded; and sending the high-level CCM frames to the corresponding ports for forwarding according to the maintenance domain and the maintenance set to which the high-level CCM frames belong. CCM frames belonging to CFM1 are sent to MEP1, and CCM frames belonging to CFM2 are sent to port C for forwarding

T3: if PE1 times out and does not receive CCM frames matching MEP1, LOC (loss of connectivity) alarm is generated; PE1 receives a CCM frame that matches MEP1, but the RDI in the frame is set, generating an RDI (remote fault indication) alarm. When an MEP1 alarm is generated, PE1 sets exception to the state of port C with MEP1 configured, so that CE1 connected with the port C senses link failure

T4: PE1 receives the CCM frame matched with MEP1, analyzes interface status TLV, if value is 1, the state of the AC side of the opposite terminal equipment is normal, if value is 2, the state of the AC side of the opposite terminal equipment is abnormal, PE1 sets the state of the port C configured with MEP1 to be abnormal, and CE1 connected with the port C senses link failure.

T5: when CFM1 on PE1 generates a LOC alarm, MEP1 sets the RDI bit in the transmitted CCM frame. Thus, when the link is single-pass (PE 1 has no received packet, but PE2 has a received packet), PE2 can receive the CCM frame with RDI set, and generate RDI alarm.

T6: MEP1 encapsulates the interface status TLV in the transmitted CCM frame. When PE1 senses a port C status exception (AC side link failure) connected to CE1, the value in the interface status TLV is set to status exception (2) and sent to PE2 with the CCM frame.

In another embodiment, the maintenance domain CFM2 is deployed on device CE1 and device CE 2. Configuring an inward MEP3 on a port A of equipment CE1, and configuring a maintenance domain and a maintenance set CFM2 to which the inward MEP belongs; another inward MEP4 is configured at port H of device CE2, MEP4 and MEP3 belong to a maintenance domain and maintenance set CFM2, and are remote from MEP3, and the CCM frame transmission period is the same as MEP 3. The maintenance domain level of CFM2 should be higher than CFM1 so that CCM frames of CFM2 can traverse the maintenance domain of CFM 1.

At CE 1:

u1: MEP1 configured on CE1 mutually sends CCM frames according to a preset period, wherein the CCM frames comprise a flag byte containing RDI bits and an interface status TLV. The CCM frames are sent out via port B and sent to the CE2 device via the network.

U2: the CE1 receives a packet from the network from the port B, and when the CE1 receives a CCM frame from the port B, it determines that the maintenance domain to which it belongs: CCM frames belonging to the same maintenance domain are sent to MEP 2; low level CCM frames are discarded; and sending the high-level CCM frames to the corresponding ports for forwarding according to the maintenance domain and the maintenance set to which the high-level CCM frames belong. CCM frames belonging to CFM2 are sent to MEP 3.

U3: the CE1 does not receive the CCM frame matching with the MEP3 after time-out, and then LOC (loss of connectivity) alarm is generated; the CE1 receives a CCM frame matching the MEP3, but the RDI in the frame is set, generating an RDI (remote fault indication) alarm. When a CFM2 alarm is generated, CE1 sets an exception to the port a status of the configured MEP3 so that CPE1 connected to it through port a senses the link failure.

U4: the CE1 receives the CCM frame matched with the MEP3, analyzes the interface status TLV, if the value is 1, the state of the user side of the opposite end device is normal, if the value is 2, the state of the user side of the opposite end device is abnormal, and the CE1 sets the state of the port a configured with the MEP3 to be abnormal, so that the CPE1 connected with the CE through the port a senses the link failure.

U5: when CFM2 on CE1 generates a LOC alarm, MEP3 sets the RDI bit in the transmitted CCM frame. Thus, when the link is single-pass (CE 1 has no received packet, but CE2 has received packet), CE2 can receive the CCM frame with RDI set, and generate RDI alarm.

U6: MEP3 encapsulates the interface status TLV in the transmitted CCM frame. When CE1 senses a port a status exception (customer side link failure) connected to CPE1, the value in the interface status TLV is set to status exception (2) and sent with the CCM frame to CE 2.

In a preferred embodiment, as shown in figure 3,

s30: if the first link edge server does not receive the first state message or the first state message has a fault alarm, the first link edge router does not receive the second state message or the second state message, or the second link edge server does not receive the first state message or the fault alarm in the first state message, and the second link edge router does not receive the second state message or the second state message, the virtual private network fault is judged;

when the virtual private network fails, the first status messages sent by the two edge servers cannot reach the destination device through the virtual private network, and the second status messages sent by the two edge routers cannot reach the destination device through the virtual private network, so that the first link cannot receive the first status messages and the second status messages.

For example, when a link between PE1 and PE2 fails, the MEPs corresponding to CFM1 and CFM2 send a link failure alarm because they do not receive the corresponding first status packet and second status packet, and finally transmit the link failure alarm to the front-end device via the edge server and the edge router, and the front-end devices of both links determine that the link location is between PE1 and PE2 according to the alarm.

S31: if the first link edge router does not receive the second state message or the second state message and the first link edge server receives the first state message with the fault alarm, judging that the link of the edge router and the edge server in the second link has a fault;

specifically, when a link failure occurs between the edge router and the edge server of the first link, the first status packet can still be received and transmitted through the virtual private network between the edge servers, but the first link edge server is in a failure position, and the first packet sent to the second link edge server will have far-end failure information. Meanwhile, because the edge router of the first link and the edge server have link failure, the second state message can not be received and transmitted, the two edge routers send link failure alarms, and the failure position is judged according to the far-end failure information carried by the alarms and the messages.

For example, when a link between PE1 and CE1 fails, MEPs in CFM1 can all normally receive and transmit first state packets, and a link noise alarm will not be sent out, but an MEP on PE1 in CFM1 of the first link is at a failure position, and the sent first state packet carries far-end failure information. MEPs in CFM2 cannot receive the second status message, MEPs in CFM2 all send link failure alarms, and at the same time, MEPs (CE 1) in CFM2 of the first link are also in a failure position, which directly notifies the front-end device of the first link. And the edge server of the second link sends the information related to the remote failure to the front-end equipment of the second link by the edge router.

S32: if the second link edge router does not receive the second state message or the fault alarm in the second state message and the edge server of the second link receives the first state message with the fault alarm, judging that the link of the edge router and the edge server in the first link has a fault;

similarly to step S32, when the failure location is symmetric, the states of the two links are exchanged.

S33: if the first link edge router receives the second state message with the fault alarm, judging the link fault of the front-end equipment and the edge router in the second link;

similarly to step S33, when the failure position is symmetrical, the states of the two links are exchanged.

S34: if the second link edge router receives the second state message with the fault alarm, the failure of the link between the front-end equipment in the first link and the edge router is judged.

Specifically, when the link between the front end device and the edge router in the first link fails, both the first status packet and the second status packet can be normally received and transmitted, but the second packet sent to the edge of the second link by the first link edge router at the failure position will have the far-end failure information.

For example, when an access circuit fault occurs in a link between the CE1 and the CPE1, both the CFM1 and the CFM2 can normally receive and transmit the first status packet and the second status packet, and a link fault alarm is not sent, but the CFM2 of the first link is in a fault position, and the two status packets sent by the CFM2 of the first link carry far-end fault information and directly notify the front-end device of the first link. And the edge server of the second link sends the information related to the remote failure to the front-end equipment of the second link by the edge router.

When a link fault occurs in the communication equipment, link fault alarms are generally sent out, the link fault alarms are collected, and the fault position can be further judged by combining the sending rule of the link fault alarms. Therefore, in the embodiment of the present invention, the receiving states of the first status packet and the second status packet, and whether the first status packet and the second status packet carry the remote failure information, are combined with the link failure alarm in the link, so as to determine the failure.

It should be noted that, although steps S30 to S34 in this embodiment are all in the transceiving state of the first link, because of the symmetric structure of the first link and the second link, a person skilled in the art can easily derive the similar situation of the second link according to this embodiment, and therefore, the description is not repeated here.

Based on the same inventive concept, the present application further provides an embodiment:

a network link failure detection and delivery system, comprising:

the first link and the second link respectively comprise an edge server, a front-end device and an edge router, and the two edge servers are connected with each other through a virtual private network;

the two edge servers are used for sending first state messages to each other, the two edge routers are used for sending second state messages to each other, if the edge servers and/or the edge routers find that a link is abnormal, the edge servers and/or the edge routers send the first state messages and/or the second state messages with fault alarms, a port of a user side of the edge servers and/or the second state messages is configured to be in an alarm state, the link abnormality comprises the received first state messages and/or the received second state messages are abnormal, and a port of the user side directly connected with the link abnormality is in the alarm state;

the edge server and/or the edge router is also used for configuring a port of a user side of the edge server and/or the edge router to be in an alarm state if the received first state message and/or the received second state message have fault alarm;

the front-end equipment is used for detecting the alarm state of a port at the user side of the edge router of the same link and judging the fault position of the link according to the receiving states of the first state message and the second state message.

As a preferred embodiment, the front end device is used for determining a link failure location, and includes:

if the first link edge server does not receive the first state message or the first state message has a fault alarm, the first link edge router does not receive the second state message or the second state message, or the second link edge server does not receive the first state message or the fault alarm in the first state message, and the second link edge router does not receive the second state message or the second state message, the virtual private network fault is judged;

if the first link edge router does not receive the second state message or the second state message and the first link edge server receives the first state message with the fault alarm, judging that the link of the edge router and the edge server in the second link has a fault;

if the second link edge router does not receive the second state message or the fault alarm in the second state message and the edge server of the second link receives the first state message with the fault alarm, judging that the link of the edge router and the edge server in the first link has a fault;

if the first link edge router receives the second state message with the fault alarm, judging the link fault of the front-end equipment and the edge router in the second link;

if the second link edge router receives the second state message with the fault alarm, the failure of the link between the front-end equipment in the first link and the edge router is judged.

Various modifications and specific examples in the foregoing method embodiments are also applicable to the system of the present embodiment, and the detailed description of the method is clear to those skilled in the art, so that the detailed description is omitted here for the sake of brevity.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Generally speaking, compared with the conventional technology and the like, the method and the system for detecting and transmitting the network link failure provided by the embodiment of the invention adopt a symmetric method with inward MEPs at two ends, are divided into two-stage deployment of a nested type according to different maintenance domains, and have the function of transmitting the failure (port state) by expanding CFM CCM frames and inserting Interface Status TLVs, so that the CFM detection and the port state monitoring of the MEPs are linked, rather than simply detecting a certain link through CFM, and the link failure in the network can be converted into the abnormal state of an end device and an adjacent Interface of the network.

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

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

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

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

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for detecting and transmitting network link failure is characterized in that the method comprises the following steps:

if the edge server and/or the edge router finds that the link is abnormal, sending a first state message and/or a second state message with a fault alarm, and configuring a port of a user side of the edge server and/or the edge router to be in an alarm state, wherein the link abnormality comprises the received first state message and/or the received second state message abnormality, and the port of the user side directly connected with the edge server and/or the edge router which finds that the link is abnormal is in the alarm state;

if the first state message and/or the second state message received by the edge server and/or the edge router has a fault alarm, configuring a port of a user side of the edge server and/or the edge router to be in an alarm state;

and the front-end equipment detects the alarm state of a port at the user side of the edge router of the same link and judges the fault position of the link according to the receiving states of the first state message and the second state message.

2. The method as claimed in claim 1, wherein said determining the location of the link failure comprises:

if the first link edge server does not receive the first state message or the first state message has a fault alarm, the first link edge router does not receive the first state message or the second state message, or the second link edge server does not receive the first state message or the fault alarm in the first state message, and the second link edge router does not receive the first state message or the second state message, the virtual private network fault is judged;

if the first link edge router does not receive the first state message or the second state message and the first link edge server receives the first state message with the fault alarm, judging that the link of the edge router and the edge server in the second link has a fault;

3. The method as claimed in claim 1, wherein the first status packet or the second status packet with the failure alarm includes a first status packet or a second status packet inserted with port status exception information.

4. The method according to claim 1, wherein the sending the first status packet and/or the second status packet with the failure alarm if the edge server and/or the edge router finds the link abnormality comprises:

in the first link or the second link, the front-end device monitors the state of a direct connection port of the edge router of the same link, and if the state is an alarm state, the front-end device inserts port state abnormal information into a sent second state message.

5. The method according to claim 1, wherein the step of sending the first status packet and/or the second status packet with the failure alarm if the edge server and/or the edge router finds the link abnormality, and the step of configuring the port on the user side of the edge server and/or the edge router to be in the alarm state comprises:

if the edge router does not receive the second state message or the second state message carries an alarm, the network link between the two edge routers has a fault, and the edge router sets a direct connection port between the edge router and the same link front-end device to be in an alarm state;

if the port in the second status message received by the edge router has a fault alarm, it indicates that the network link between the edge router and the front-end device in the other link has a fault, and the edge router sets the direct connection port between the edge router and the front-end device in the same link as the alarm state.

6. The method as claimed in claim 1, wherein the step of sending the first status message and the second status message to each other between the two edge servers and the two edge routers comprises:

and the two edge routers mutually send CCM frames carrying the second state message.

7. The method of claim 1 wherein the network link failure detection and delivery method,

the two front-end devices acquire whether a link fault exists in the network by monitoring the states of the ports directly connected with the edge router.

8. The method as claimed in claim 1, wherein the fault alarm is a data frame set in the first status packet and the second status packet.

9. A network link failure detection and delivery system, comprising:

the two edge servers are used for sending first state messages to each other, the two edge routers are used for sending second state messages to each other, if the edge servers and/or the edge routers find that a link is abnormal, the first state messages and/or the second state messages with fault alarms are sent, a port of a user side of the edge routers is configured to be in an alarm state, the link abnormity comprises the received first state messages and/or the received second state messages which are abnormal, and the port of the user side directly connected with the edge servers and/or the edge routers which find the link abnormity is in an alarm state;

10. The system of claim 9, wherein the front-end device is configured to determine a location of a link failure, comprising: