CN100446476C - Method and device for intercommunication of network fault detection results - Google Patents

Abstract

The invention discloses a method and a device for intercommunicating network fault detection results, belonging to the field of network management. In order to solve the problem of intercommunication of network fault detection results, the present invention proposes a method of establishing the state association of two adjacent links, and corresponding the association to the detection instance table of the corresponding link. The method effectively solves the problem of intercommunication of network fault detection results. The invention also provides a network fault detection result intercommunication device, which also realizes the problem of network fault detection result intercommunication.

Description

Method and device for intercommunication of network fault detection results

technical field

The invention relates to the field of network management, in particular to a method and device for intercommunicating network fault detection results.

Background technique

Ethernet technology is easy to use, low in price, and its bandwidth can be continuously improved. Whether it is a service or a network structure, it has been widely used in enterprise networks, metropolitan area networks, and wide area networks. However, traditional Ethernet The maintainability and operability capabilities are relatively weak. With the gradual expansion of the scope of Ethernet promotion, the demand for Ethernet OAM (Operations, Administration and Maintenance, operation, management and maintenance) functions is becoming stronger and stronger. OAM technology is a technology that provides operable and maintainable functions. It can automatically detect various failures in the network, and then take corresponding remedial measures to avoid the expansion of the failure or eliminate the negative impact of the failure as much as possible.

PWE3 (Pseudo Wire Emulation Edge-to-Edge end-to-end pseudowire emulation) was originally called Martini Draft (Martini Draft), which is an end-to-end Layer 2 service bearing technology. Emulate Ethernet over Multiprotocol Label Switching. PWE3 simulates various point-to-point service mechanisms on the Packet Switched Network (PSN). The simulated services can be TDM (Time Division Multiplex) leased line, ATM (Asynchronous Transfer Mode), FR (Frame Relay) or Ethernet, etc., PWE3 uses the tunnel mechanism on the PSN to simulate the necessary attributes of a service. The tunnel here is called a virtual wire (Pseudo Wire PW). PWE3 can encapsulate the protocol data unit (Protocol Data UnitPDU) of a specific service, and the PDU contains the data and control information necessary to simulate a specific service. Operators can use the PWE3 mechanism to transfer all transport services to a converged network, such as an IP/MPLS network. From the user's point of view, the virtual line simulated by PWE3 can be considered as a dedicated link or circuit.

802.1ag ETHOAM (Ethernet operation, management and maintenance) can solve the end-to-end Ethernet OAM problem, and can also span multiple bridge nodes. It is an OAM that can distinguish VLANs (Virtual Local Area Networks), and the fault detection function of 802.1ag ETHOAM It is realized through the continuity check message (CCM-Continuity Check Message). The main functions include: fault detection function, fault confirmation function (Ping), fault location and isolation function (TraceRoute), fault notification and alarm suppression function.

BFD detection technology can solve the problem of PW fault detection. BFD (Bidirectional Forwarding Detection) detection technology has the advantages of simple detection mechanism, strong flexibility, and good versatility, so it has been used in the fault detection of pseudo-wire simulation. Wide range of applications. BFD for PW is one of the PW fault detection methods, and its fault detection is implemented by detecting Hello packets.

A basic ETH PWE3 network architecture is shown in Figure 1. A PW is established between CE1 and CE2 at the customer edge, and Ethernet access is used between CE1 and CE2 and PE1 and PE2 at the provider edge. , here we do not distinguish the specific signaling implementation of the PW, and simply see that there is a PW between PE1 and PE2. At present, in order to quickly switch to other links when a fault occurs, it is necessary to quickly discover the fault. The Ethernet link between CE1 and PE1 can perform fast fault detection through the 802.1ag ETHOAM fault monitoring mechanism. For PW, we use BFD for PW detection technology to perform fast fault detection. The detection between CE2 and PE2 and between CE1 and PE1 The mechanism is the same. In this way, both the AC (Attachment Circuit) link and the PW link can perform independent fast fault detection, but how to notify the AC link of the PW link fault detection result, and how to report the remote AC link fault detection result It is notified to the PW side, and then further notified to the near end, so as to realize end-to-end fast detection, which is a problem to be solved.

Contents of the invention

In order to solve the problem of intercommunication of network fault detection results, the present invention proposes a method of establishing a state association of two adjacent links, and corresponding the associated index to the detection instance table of the corresponding link. The method It includes establishing a state association of two adjacent links, and corresponding the index of the association to the detection instance table of the corresponding link, and performing the following steps:

Step A: Detect the link, and after finding a link failure, search for the corresponding state association table according to the corresponding relationship between the detection instance table on the link and the index associated with the state, and save the state association table in the state association table The state bit of the link is set to an error state; step B: before sending a detection message to the adjacent link of the link, check the state of the link according to the state association of the two adjacent links;

Step C: If the status bit of the current link is in an error state, set a detection message containing an error flag bit, and send a detection message to the adjacent link.

The establishment of the state association of two adjacent links specifically includes: establishing a linearly indexed state association table on the common data area of the two adjacent links, and corresponding the state association table to the detection instance of the corresponding link on the table.

The establishment of the state association of two adjacent links specifically includes: adding an index of the detection instance table of the adjacent link and a state bit of the adjacent link to the detection instance table of the link.

The network is an Ethernet PWE3 network, and the two adjacent links are a PW link and an AC link.

The present invention also provides a network fault detection result intercommunication device, the device includes an initialization module, a link detection module, a status bit setting module, a status bit checking module, and a detection message sending module;

The initialization module is used to establish the state association of two adjacent links, and correspond the index of the association to the detection instance table of the corresponding link;

The link detection module is used to detect the link status, and send the link status to the status bit setting module;

The status bit setting module is used to receive the link status sent by the link detection module, and after finding a link failure, search for a corresponding status association table according to the detection instance table on the link, and associate the status The status bit of this link in the table is set to error status;

The status bit checking module is used to check the status of the link according to the status association of the two adjacent links before sending the detection message to the adjacent link of the link, and check the status of the link The status is sent to the detection message sending module;

The detection message sending module is used to receive the status of the link sent by the status bit viewing module, if the status bit of the link is an error state, set the detection message containing the error flag bit, and send to all The adjacent link sends a detection packet.

The initialization module establishes an association module for the state table, which is used to establish a state association table with a linear index on the public data area of two adjacent links, and correspond the index of the state association table to the detection instance of the corresponding link on the table;

The initialization module is a link monitoring module, which is used to add the index of the detection instance table of the adjacent link and the status bit of the adjacent link to the detection instance table of the link.

The technical proposal of the invention effectively solves the problem of intercommunication of network fault detection results.

Description of drawings

Figure 1 is a network architecture diagram of ETH PWE3;

Fig. 2 is the method flowchart of embodiment 1 of the present invention;

Fig. 3 is the method flowchart of embodiment 2 of the present invention;

Fig. 4 is the method flowchart of embodiment 3 of the present invention;

Fig. 5 is the method flowchart of embodiment 4 of the present invention;

Fig. 6 is a structural diagram of a device for intercommunicating network fault detection results according to the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Referring to Figure 1, the 802.1ag ETHOAM used between CE and PE is a way for both ends of the AC link to continuously send CCM (Continuity Check Message) messages to each other, so the network architecture of ETH PWE3 is a symmetrical model. At present, the control plane and the forwarding plane of most routers are separated. The detection of BFD for PW and ETHOAM is completed by the forwarding plane. In order to achieve the consistency between the control plane and the forwarding Faults detected by PW and ETH OAM require the forwarding plane to directly change the relevant link state table and send it to the control plane at the same time. In this case, some processing needs to be performed at the junction (PE1, PE2) to realize end-to-end fast detection intercommunication.

The present invention proposes to establish a linearly indexed PW and AC state table on the public data area at the junction of the PW link and the AC link, and associate the indexes of the PW and AC state tables with the corresponding BFD and ETHOAM detection In the example table of ETHOAM and BFD, you need to check the status bits of PW or AC in the corresponding PW and AC status tables when detecting ETHOAM and BFD, and send detection messages according to the results of the status bits of PW or AC. This method can simply Realize the intercommunication of fault detection results between PW and ETH.

Example 1

Referring to Figure 1 and Figure 2, when the PW link fails, that is, PE1 does not receive the Hello packet from PE2, or receives the Hello packet with the DOWN status bit from PE2, it needs to notify the fault detection result to AC link, the specific steps are as follows:

Step 101: Create a linearly indexed PW and AC state table in the public data area on PE1 and PE2 respectively, and associate the indexes of the state table with the instance tables corresponding to BFD detection and ETHOAM detection;

Step 102: Use BFD detection technology to detect the link PW, and detect that the link between PE1 and PE2 is faulty;

Step 103: The PE searches the corresponding PW and AC state table according to the state table index on the BFD detection instance table, and sets the PW state bit therein as DOWN;

Step 104: Use the ETHOAM detection technology to detect the AC link, the PE searches the corresponding PW and AC state table according to the state table index on the ETHOAM detection instance table, and the PE checks the corresponding PW and the PW state in the AC state table bit, according to the PW status bit, send a CCM message containing the RDI flag bit to 1 to CE1 and CE2 respectively;

Step 105: After CE1 and CE2 receive the CCM message with the RDI flag bit set to 1, they will know that the link is faulty. If there is a backup link, then CE1 and CE2 will quickly switch to the backup link, otherwise report Link failed.

Example 2

Referring to Figure 1 and Figure 3, when the remote AC link (the link between PE2 and CE2) fails, that is, PE2 does not receive the CCM message from CE2, or receives a CCM message with the RDI flag from CE2. CCM message, and notify the fault detection result to the near-end AC link (the link between PE1 and CE1). The specific steps are as follows:

Step 201: Create a linearly indexed PW and AC state table in the public data area on PE1 and PE2 respectively, and associate the indexes of the state table with the instance tables corresponding to BFD detection and ETHOAM detection;

Step 202: Use ETHOAM detection technology to detect the remote AC link, and detect that the link between PE2 and CE2 is faulty;

Step 203: PE2 searches the corresponding PW and AC state table according to the index of the PW and AC state table on the ETHOAM detection instance table, and sets the AC state bit in the state table to DOWN;

Step 204: Use the BFD detection technology to detect the PW link. PE2 searches the corresponding PW and AC state table according to the state table index on the BFD detection instance table, and PE2 checks the AC state in the corresponding PW and AC state table. bit, according to the AC status bit, send a Hello message containing the fault diagnosis log of the cascading path to PE1;

Step 205: After PE1 receives the Hello message containing the cascading path fault diagnosis log, PE1 searches the corresponding PW and AC state table according to the state table index in the BFD detection instance table, and sets the PW state bit in it to DOWN;

Step 206: Use the ETHOAM detection technology to detect the near-end AC link. PE1 searches the corresponding PW and AC state table according to the index of the PW and AC state table on the ETHOAM detection instance table, and PE1 checks its corresponding PW and AC The PW status bit in the status table, according to the PW status bit, send a CCM message with the RDI flag bit set to 1 to CE1;

Step 207: After CE1 receives the CCM message with the RDI flag bit set to 1, it knows that the link is faulty. If there is a backup link, CE1 will quickly switch to the backup link; otherwise, it will report that the link is faulty. .

In the technical scheme of the present invention, more flag bits can also be stored in the PW and AC state tables, for example: PWdown for expire, PW down for neighbor, PW down for AC, AC down for expire, AC down forRDI, AC down for PW, so that the location of the fault can be located by viewing the PW and AC status tables. In addition, when ETHOAM and BFD detect link recovery, they are respectively responsible for changing the status of the detected link AC or PW in the PW and AC status table to UP.

The present invention also proposes a method for establishing a direct correspondence between the ETHOAM monitoring the AC and the BFD monitoring the PW through the correspondence between the AC and the PW on the PE device, and also realizing the fault detection intercommunication of the Ethernet PWE3 network.

Example 3

Referring to Figure 1 and Figure 4, when the PW link fails, that is, PE1 does not receive the Hello packet from PE2, or receives the Hello packet with the status bit DOWN from PE2, it notifies the AC of the fault detection result. link, the specific steps are as follows:

Step 301: Add the index of the BFD detection instance table and the PW status bit in the ETHOAM detection instance table of the AC link;

Step 302: Add the index of the ETHOAM detection instance table and the AC status bit in the BFD detection instance table of the PW link;

Step 303: Use the BFD detection technology to detect the link PW, and detect that the link between PE1 and PE2 is faulty, and PE1 and PE2 respectively search for the corresponding ETHOAM according to the index of the ETHOAM detection instance table in the BFD detection instance table Detect the instance table, and set the PW status bit in the ETHOAM detection instance table to DOWN;

Step 304: Use the ETHOAM detection technology to detect the AC link. PE1 and PE2 check the PW status bits in their corresponding ETHOAM detection instance tables, and send CCM reports containing the RDI flag bit to 1 to CE1 and CE2 respectively according to the PW status bits. arts;

Step 305: After CE1 and CE2 receive the CCM message with the RDI flag bit as 1, they know that the link is faulty. If there is a backup link, then CE1 and CE2 will quickly switch to the backup link, otherwise they will report that the link is faulty. Road failure.

Example 4

Referring to Figure 1 and Figure 5, when the remote AC link (the link between PE2 and CE2) fails, that is, PE2 does not receive the CCM message from CE2, or receives a CCM message with the RDI flag from CE2. CCM message, and notify the fault detection result to the near-end AC link (the link between PE1 and CE1). The specific steps are as follows:

Step 401: Add the index of the BFD detection instance table and the PW status bit in the ETHOAM detection instance table of the AC link;

Step 402: Add the index of the ETHOAM detection instance table and the AC status bit in the BFD detection instance table of the PW link;

Step 403: Use the ETHOAM detection technology to detect the remote AC link, and detect that the link between PE2 and CE2 is faulty, and PE2 searches for its corresponding BFD detection instance according to the BFD detection instance table index in the ETHOAM detection instance table table, and set the AC status bit in the BFD detection instance table to DOWN;

Step 404: Use the BFD detection technology to detect the link PW, PE2 checks the AC status bit in its corresponding BFD detection instance table, and sends a Hello message containing the cascading path fault diagnosis log to PE1 according to the AC status bit;

Step 405: After PE1 receives the Hello packet containing the cascading path fault diagnosis log, PE1 searches for the corresponding ETHOAM detection instance table according to the ETHOAM detection instance table index in the BFD detection instance table, and saves the ETHOAM detection instance table in the ETHOAM detection instance table. The PW status bit is set to DOWN;

Step 406: Use the ETHOAM detection technology to detect the near-end AC link, PE1 checks the PW status bit in its corresponding ETHOAM detection instance table, and sends a CCM message with the RDI flag bit as 1 to CE1 according to the PW status bit;

Step 407: After CE1 receives the CCM message with the RDI flag bit set to 1, it knows that the link is faulty. If there is a backup link, then CE1 will quickly switch to the backup link; otherwise, it will report that the link is faulty. .

Referring to Fig. 6, the present invention also provides a device for intercommunicating network fault detection results, said device comprising an initialization module, a link detection module, a status bit setting module, a status bit checking module, and a detection message sending module;

The initialization module is used to establish the state association of two adjacent links, and correspond the association to the detection instance table of the corresponding link;

The link detection module is used to detect the link status, and send the link status to the status bit setting module;

The status bit setting module is used to receive the link status sent by the link detection module, and after finding a link failure, set the link according to the corresponding relationship between the detection instance table on the link and the status. status;

The status bit checking module is used to check the status of the link according to the status association of the two adjacent links before sending the detection message to the adjacent link of the link, and check the status of the link The status is sent to the detection message sending module;

The detection message sending module is used to receive the state of the link sent by the status bit checking module, set the detection message according to the state of the link, and send the detection message to the adjacent link.

The initialization module establishes an association module for the state table, which is used to establish a state association table of a linear index on the public data area of two adjacent links, and correspond the state association table to the detection instance table of the corresponding link ;

The status bit setting module is used to receive the link status sent by the link detection module, and after finding a link failure, search for a corresponding status association table according to the detection instance table on the link, and associate the status The status bit of this link in the table is set to error status;

The status bit checking module is used to check the status of the link according to the status association table on the public data area of the two adjacent links before sending the detection message to the adjacent link of the link, and Send the state of the current link to the detection message sending module;

The detection message sending module is used to receive the state of the link sent by the status bit viewing module, if the status bit of the link is an error state, then set the detection message containing the error flag bit, and send The adjacent link sends a detection message.

The initialization module is a link monitoring module, which is used to add the index of the detection instance table of the adjacent link and the status bit of the adjacent link in the detection instance table of the link;

The status bit setting module is used to receive the link status sent by the link detection module, and after finding a link failure, search the adjacent link detection instance table according to the detection instance table on this link, and set the The status bit of this link in the adjacent link detection instance table is set to an error state;

The status bit checking module is used to check the status of the link in the adjacent link detection instance table before sending the detection message to the adjacent link of the link, and compare the status of the link Send to the detection message sending module;

The detection message sending module is used to receive the state of the link sent by the status bit viewing module, if the status bit of the link is an error state, then set the detection message containing the error flag bit, and send The adjacent link sends a detection message.

The embodiments described above are only one of the more preferred specific implementation modes of the present invention, and the usual changes and substitutions performed by those skilled in the art within the scope of the technical solution of the present invention shall be included in the protection scope of the present invention.

Claims (7)

1. a method for network fault detection result intercommunication, it is characterized in that, set up the state association of two adjacent links, and the index of described association is corresponding on the detection example table of corresponding link, and perform the following steps: Step A: Detect the link, and after finding a link failure, search for the corresponding state association table according to the corresponding relationship between the detection instance table on the link and the index associated with the state, and save the state association table in the state association table The status bit of the link is set to an error state; Step B: Before sending a detection message to the adjacent link of the link, check the state of the link according to the state association of the two adjacent links; Step C: If the status bit of the current link is in an error state, set a detection message containing an error flag bit, and send a detection message to the adjacent link. 2. The method for intercommunication of network fault detection results as claimed in claim 1, wherein said setting up the state association of two adjacent links specifically comprises: A state association table of linear index is established on the common data area of two adjacent links, and the index of the state association table is corresponding to the detection instance table of the corresponding link. 3. The method for intercommunication of network fault detection results as claimed in claim 1, wherein said establishing the state association of two adjacent links specifically comprises: The index of the detection instance table of the adjacent link and the state bit of the adjacent link are added in the detection instance table of the link. 4. The method for intercommunication of network fault detection results as claimed in claim 1, 2 or 3, wherein the network is an Ethernet PWE3 network, and the two adjacent links are a PW link and an AC link . 5. A device for intercommunicating network fault detection results, characterized in that, The device includes an initialization module, a link detection module, a status bit setting module, a status bit checking module, and a detection message sending module; The initialization module is used to establish the state association of two adjacent links, and correspond the index of the association to the detection instance table of the corresponding link; The link detection module is used to detect the link status, and send the link status to the status bit setting module; The status bit setting module is used to receive the link status sent by the link detection module, and after finding a link failure, search for a corresponding status association table according to the detection instance table on the link, and associate the status The status bit of this link in the table is set to error status; The status bit checking module is used to check the status of the link according to the status association of the two adjacent links before sending the detection message to the adjacent link of the link, and check the status of the link The status is sent to the detection message sending module; The detection message sending module is used to receive the status of the link sent by the status bit viewing module, if the status bit of the link is an error state, set the detection message containing the error flag bit, and send to all The adjacent link sends a detection packet. 6. The device for intercommunicating network fault detection results as claimed in claim 5, characterized in that: The initialization module establishes an association module for the state table, which is used to establish a state association table with a linear index on the public data area of two adjacent links, and correspond the index of the state association table to the detection instance of the corresponding link on the table. 7. The device for intercommunicating network fault detection results as claimed in claim 5, characterized in that: The initialization module is a link monitoring module, which is used to add the index of the detection instance table of the adjacent link and the status bit of the adjacent link to the detection instance table of the link.

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