Evaluation and detection method of FRER redundant path based on switching delay accumulation function

Abstract

The invention discloses an FRER redundant path evaluation and detection method based on an exchange delay accumulation function, and the method comprises the steps: defining four new SV / GOOSE messages according to an existing SV / GOOSE message structure, transmitting the messages on an FRER redundant path, carrying out the start detection and cycle detection of the redundant path, and carrying out the detection of the FRER redundant path. Reliability evaluation, real-time fault detection and time delay measurement of the FRER redundant path are realized. By adopting the technical scheme disclosed by the invention, the problems that in the original FRER technology, reliability evaluation of redundant paths is insufficient, packet loss is caused by uncertainty of end-to-end time delay, repeated frame elimination is abnormal, and data consistency and deterministic transmission are influenced are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of time-sensitive networks (TSNs), and in particular to a method for evaluating and detecting redundant FRER paths based on a switching delay accumulation function. Background Art

[0002] FRER (Frame Replication and Elimination for Reliability) technology in TSN (Time-Sensitive Networking) improves network reliability through redundant transmission, but some issues still exist, including:

[0003] 1. Inadequate path reliability assessment: Traditional FRER mechanisms typically only consider whether the paths are disjoint when selecting redundant paths, without evaluating the reliability of the paths themselves (such as link quality and congestion). This can result in the selected redundant paths still having a high risk of packet loss or delay in actual transmission.

[0004] 2. Increased end-to-end delay uncertainty: FRER improves reliability by replicating frames and transmitting them over different paths, but it can also increase end-to-end delay jitter. For example, differences in transmission delay across different paths can cause the receiver to wait for frames that arrive later, affecting deterministic transmission. Summary of the Invention

[0005] To address the above technical issues, the present invention discloses a method for reliability assessment, real-time fault detection, and delay measurement of FRER redundant paths based on the exchange delay accumulation function. Four new SV / GOOSE messages are defined based on the existing SV / GOOSE message structure. These messages are transmitted over the FRER redundant paths, and startup and periodic detection are performed on the redundant paths, thereby achieving reliability assessment, real-time fault detection, and delay measurement of the FRER redundant paths. The technical solution disclosed in the present invention solves the problems of insufficient redundant path reliability assessment in existing FRER technology, as well as packet loss and duplicate frame elimination anomalies caused by end-to-end delay uncertainty, which affect data consistency and deterministic transmission.

[0006] In order to achieve the above-mentioned object, the technical solution of the present invention provides a method for evaluating and detecting FRER redundant paths based on a switching delay accumulation function, which includes performing FRER redundant path startup detection before the FRER function is enabled, and the FRER redundant path startup detection includes the following steps: S1: the FRER replication device configures a first path status table and a first timer, and after starting the first timer, sends a startup detection message to each redundant path, the first path status table includes a redundant path identifier Path ID, a redundant path connection port Port ID, a redundant path status Status, and a message transmission delay Latency; S2: the FRER elimination device configures a second path status table and a second timer, and after starting the second timer, performs a validity judgment on each received startup detection message, and based on the corresponding field value and delay of the received startup detection message, sets the Status of the corresponding entry in the second path status table to Fail and sends a path failure message to the corresponding redundant path, or sets the Status of the corresponding entry to Success and sends a path validation message to the corresponding redundant path, the second path status table includes a redundant path identifier Path ID, a redundant path connection port Port ID, a redundant path status Status, and a message transmission delay Latency. ID, redundant path status Status; if the FRER elimination device has not received any startup detection message at the end of the second timer, the FRER elimination device does not perform any processing; S3: before the end of the first timer, if the FRER replication device receives a path failure message, the Status of the corresponding entry in the first path status table is set to Fail; if a path validation message is received, the Status of the corresponding entry is set to Success, and then the Latency is updated according to the exchange delay accumulation function; if the FRER replication device has not received any path failure message and path validation message at the end of the first timer, the FRER replication device does not perform any processing; wherein, the startup detection message, the path failure message and the path validation message are defined according to the existing SV / GOOSE message structure.

[0007] Furthermore, the method further includes: after all FRER redundant paths have been detected by the FRER redundant path startup, the FRER function is started, and the FRER redundant path periodic detection is started while the FRER function is working, and the FRER redundant path periodic detection includes the following steps: T1: the FRER replication device is configured to indicate the duration of each cycle of the periodic detection. In each detection cycle, the FRER replication device first resets the Status in the first path status table to Fail, resets the Latency to 0, and after starting the third timer, sends a heartbeat detection message to each redundant path. The heartbeat detection message is defined according to the existing SV / GOOSE message structure; T2: the FRER elimination device sends a heartbeat detection message in each detection cycle. During the test, the FRER replication device receives a heartbeat detection message. If the received heartbeat detection message is legal and the corresponding field value and delay of the heartbeat detection message meet certain conditions, a path validation message is sent to the corresponding redundant path; otherwise, no processing is performed and the device continues to wait for the next heartbeat detection message until the cycle detection is closed; T3: before the end of the third timer, if the FRER replication device receives a path validation message, the Status of the corresponding entry in the first path status table is set to Success, and the Latency is updated according to the exchange delay accumulation function; T4: at the end of the third timer, the FRER replication device checks all Status in the first path status table. If Status = Fail exists, the fault is reported and the Path ID of the redundant path with the fault is carried, and then the cycle detection is ended; if Status = Fail does not exist, a new round of FRER redundant path cycle detection is automatically started.

[0008] Furthermore, the switching delay accumulation function uses reserved fields in the SV / GOOSE message, which include the test mode flag Test, the overflow flag OVF, the type field Type, the path identification field PID, the reserved bit and the application reference time ART, wherein different message types are defined by configuring the Type value.

[0009] Furthermore, in step S2, the legitimacy of the startup probe message is judged, including: using the port that receives the startup probe message as the Port ID, retrieving the corresponding Path ID in the second path status table; if the PID and Path ID of the startup probe message are inconsistent, the message is considered illegal, no processing is performed, and the next startup probe message is continued to be waited until the second timer ends; if they are consistent, the next judgment is continued.

[0010] Furthermore, in step S2, under the following circumstances, the Status of the corresponding entry in the second path status table is set to Fail, and a path failure message is sent to the corresponding redundant path: (1) If the OVF of the startup detection message is equal to 1, according to the switching delay accumulation function, it is considered that the corresponding redundant path cannot meet the normal operation of the FRER function; (2) If the OVF of the startup detection message is equal to 0, ART is also equal to 0, according to the switching delay accumulation function, it is considered that the corresponding redundant path does not support switching delay accumulation; (3) If the OVF of the startup detection message is equal to 0, ART is not equal to 0, then according to the switching delay accumulation function, the transmission delay on the redundant path is converted by the value of ART. If the delay is not within a reasonable range, it is considered that the corresponding redundant path cannot meet the normal operation of the FRER function.

[0011] Furthermore, in step S2, under the following circumstances, the Status of the corresponding entry in the second path status table is set to Success, and a path validation message is sent to the corresponding redundant path: if the OVF of the startup detection message is equal to 0, the ART is not equal to 0, and the delay calculated according to the switching delay accumulation function is within a reasonable range, then it is considered that the redundant path can meet the normal operation of the FRER function.

[0012] Furthermore, the method further includes: S4: performing reliability evaluation on the FRER redundant path according to the first path status table and in combination with the second path status table, wherein, (1) if Status=None in the first path status table and Status=None in the second path status table, then the corresponding redundant path has a fault in the transmission direction from the FRER replication device to the FRER elimination device, and the fault is caused by the risk of packet loss in the path; (2) if Status=None in the first path status table and Status=Success in the second path status table, then the corresponding redundant path has a fault in the transmission direction from the FRER elimination device to the FRER replication device, and the fault is caused by the risk of packet loss in the path; (3) if Status=Success in the first path status table If Status=None in the first path status table and Status=Fail in the second path status table, then the corresponding redundant path has faults in both transmission directions. The causes of the fault in the transmission direction from the FRER replication device to the FRER elimination device include excessive path delay or the path does not support the switching delay accumulation function. The causes of the fault in the transmission direction from the FRER elimination device to the FRER replication device are that there is a risk of packet loss on the path. (4) If Status=Fail in the first path status table and Status=Fail in the second path status table, then the corresponding redundant path has faults in the transmission direction from the FRER replication device to the FRER elimination device. The causes of the fault include excessive path delay, unstable path delay, and the path does not support the switching delay accumulation function.

[0013] Furthermore, in step T2, a path validation message is sent to the corresponding redundant path under the following circumstances: if the OVF of the heartbeat detection message is equal to 0, the ART is not equal to 0, and the delay converted according to the exchange delay accumulation function is within a reasonable range, then it is considered that the corresponding redundant path can currently continue to meet the normal operation of the FRER function.

[0014] Furthermore, in step T2, in the following cases, no processing is performed and the next heartbeat detection message is continued to be waited until the cycle detection is closed: (1) If the OVF of the heartbeat detection message is equal to 1, according to the switching delay accumulation function, it is considered that the corresponding redundant path has a large delay or an intermediate device failure problem, and the normal operation of the FRER function cannot continue to be satisfied; (2) If the OVF of the heartbeat detection message is equal to 0, ART is also equal to 0, according to the switching delay accumulation function, it is considered that the corresponding redundant path cannot continue to support switching delay accumulation; (3) If the OVF of the heartbeat detection message is equal to 0, ART is not equal to 0, then according to the switching delay accumulation function, the transmission delay on the redundant path is converted by the value of ART. If the delay is not within a reasonable range, it is considered that congestion or delay instability occurs on the corresponding redundant path, and the normal operation of the FRER function cannot continue to be satisfied.

[0015] Furthermore, in step T4, if all FRER redundant paths fail, the FRER replication device automatically stops the FRER function; if part of the FRER redundant paths fail, the FRER replication device chooses to stop transmitting data to the failed path or chooses not to process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the SV / GOOSE message format;

[0018] Figure 2 This is a diagram of the reserved fields of the SV / GOOSE message (switch delay mark format);

[0019] Figure 3 Schematic diagram of the transmission direction of the startup detection message / heartbeat detection message of the present invention;

[0020] Figure 4 Schematic diagram of the transmission direction of the path validation message / path failure message of the present invention;

[0021] Figure 5 It is a flow chart of the FRER redundant path startup detection at the FRER replication device end of the present invention;

[0022] Figure 6 This is a flow chart of starting detection of FRER redundant paths at the FRER elimination device end of the present invention;

[0023] Figure 7 It is a flow chart of FRER redundant path period detection at the FRER replication device end of the present invention;

[0024] Figure 8 This is a flow chart of the FRER redundant path period detection at the FRER elimination device end of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] The method provided by the present invention provides reliability evaluation, real-time fault detection and delay measurement of the FRER redundant path by performing FRER redundant path startup detection before the FRER function is turned on and performing FRER redundant path periodic detection after the FRER function is turned on.

[0027] 1. FRER redundant path startup detection

[0028] Before the FRER function is enabled, enable the FRER redundant path startup test on the FRER replication device and follow the Figure 5 The process shown is tested.

[0029] Timer 1 is configured on the FRER replication device. Startup detection is enabled, Timer 1 is initialized, and the timer is started.

[0030] The FRER replication device is configured with the path status table shown in Table 1. The Path ID in the table is Figure 3 / Figure 4 The table shows the identifier of the FRER redundant path. The Port ID in the table is the port of the FRER replication device connected to the corresponding redundant path. The Status in the table is the status of the corresponding redundant path. When the startup detection is turned on, the initial value of Status is None. The Latency in the table is the delay of the corresponding redundant path transmitting the startup detection message, and the initial value is 0.

[0031] Table 1

[0032] Path ID Port ID Status Latency

[0033] In Table 1, Path ID is the identifier of the FRER redundant path, Port ID is the local port of the FRER replication device used to connect to the FRER redundant path, Status is the status of the FRER redundant path, the initial value is None, and Latency is the delay of the FRER redundant path.

[0034] The FRER replication device sends a startup detection message to each redundant path, which can be an SV (Sampled Value) message or a GOOSE (Generic Object Oriented Substation Event) message. Figure 1 and Figure 2 The diagram shows the structure of the message. Figure 2 This is a structural diagram of the reserved fields for SV / GOOSE messages, which are also the message fields required for the switching delay accumulation function. Among them, Type and PID are two new definitions of the 5-bit width in the originally reserved 6-bit position in the present invention, and the specific meanings are as follows: Type (3 bits): type field, representing the SV / GOOSE message type, 1 is the startup detection message, 2 is the path validation message, 3 is the path failure message, and 4 is the heartbeat detection message; PID (2 bits): path index, path identification field, used to identify different FRER redundant paths, 1 is FRER redundant path one, and 2 is FRER redundant path two. In the startup detection message, set Test (test mode flag) = 0, OVF (overflow flag) = 0, Type = 1, PID = Path ID in the path status table shown in Table 1, Reserved = 0, ART = 0; the startup detection message is in accordance with Figure 3 Transmitted in the direction shown, it reaches the FRER elimination device, Figure 3 The intermediate devices 1 - 4 shown can calculate the transmission delay of the redundant path according to the switching delay accumulation function, and edit the OVF and ART fields of the startup detection message accordingly.

[0035] After receiving the first startup detection message, the FRER elimination device starts the FRER redundant path startup detection and Figure 6 The process shown is tested.

[0036] The FRER elimination device is configured with Timer 2. Startup detection is enabled, Timer 2 is initialized, and the timer is started.

[0037] The FRER elimination device is configured with the path status table shown in Table 2. The Path ID in the table is Figure 3 / Figure 4The table shows the identifier of the FRER redundant path. The Port ID in the table is the port to which the FRER elimination device is connected to the corresponding redundant path. The Status in the table is the status of the corresponding redundant path. When the startup detection is turned on, the initial value of Status is None.

[0038] Table 2

[0039] Path ID Port ID Status

[0040] In Table 2, Path ID is the identifier of the FRER redundant path, Port ID is the local port of the FRER elimination device used to connect to the FRER redundant path, Status is the status of the FRER redundant path, and the initial value is None.

[0041] Before Timer 2 expires, the FRER elimination device verifies the validity of each startup probe message it receives. Using the port on which the startup probe message was received as the Port ID, it retrieves the corresponding Path ID from the path status table shown in Table 2. If the startup probe message's PID and Path ID do not match, the message is considered invalid and is not processed. The device then waits for the next startup probe message until Timer 2 expires. If they match, the device proceeds to the next step.

[0042] If the OVF of the startup detection message is equal to 1, according to the switching delay accumulation function, it is considered that there are problems such as excessive delay or intermediate device failure on the redundant path, which cannot meet the normal operation of the FRER function.

[0043] If the OVF of the startup detection message is equal to 0 and the ART is also equal to 0, according to the switch delay accumulation function, it is considered that the redundant path does not support switch delay accumulation.

[0044] If the OVF of the startup probe message is equal to 0 and ART is not equal to 0, then according to the exchange delay accumulation function, the transmission delay on the redundant path is converted by the ART value. If the delay is not within a reasonable range, it is considered that there are congestion or delay instability on the redundant path, which cannot meet the normal operation of the FRER function.

[0045] If the judgment result is one of the above three situations, the Status of the corresponding entry in the path status table shown in Table 2 is set to Fail, and then the FRER elimination device will send a path failure message to the corresponding redundant path, which can be an SV message or a GOOSE message. Figure 1 and Figure 2The following is the structure of the message. In the path failure message, set Test = 0, OVF = 1, Type = 3, PID = Path ID in the path status table shown in Table 2, Reserved = 0, ART = 0xFFFFFF; the path failure message is as follows Figure 4 Transmitted in the direction shown, it reaches the FRER replication device, and according to the exchange delay accumulation function, Figure 4 The intermediate devices 1-4 shown do not edit the path failure message.

[0046] If the OVF of the startup detection message is equal to 0, the ART is not equal to 0, and the delay calculated by the exchange delay accumulation function is within a reasonable range, it is considered that the redundant path can meet the normal operation of the FRER function. Then, in the path status table shown in Table 2, the Status of the corresponding entry is set to Success, and then the FRER elimination device will send a path validation message to the corresponding redundant path, which can be an SV message or a GOOSE message. Figure 1 and Figure 2 The following is the structure of the message. In the path validation message, set Test = 0, OVF = 1, Type = 2, PID = Path ID in the path status table shown in Table 2, Reserved = 0, ART = ART in the startup detection message; the path validation message is as follows Figure 4 Transmitted in the direction shown, it reaches the FRER replication device, and according to the exchange delay accumulation function, Figure 4 The intermediate devices 1-4 shown do not edit the path validation message.

[0047] Before Timer 1 expires, the FRER replica device processes each received Path Failure / Path Validation message accordingly. If a Path Failure message is received, the Status of the corresponding entry in the Path Status Table (Table 1) is set to Fail. If a Path Validation message is received, the Status of the corresponding entry is set to Success. The switch delay accumulation function then calculates the latency using the ART in the message and sets the Latency of the corresponding entry in the Path Status Table (Table 1) to that latency.

[0048] If the FRER replica device does not receive any path failure message or path validation message when timer Timer 1 ends, the FRER replica device does not perform any processing.

[0049] If the FRER elimination device does not receive any startup detection message when timer Timer 2 ends, the FRER elimination device does not perform any processing.

[0050] 2. FRER redundant path startup detection result judgment

[0051] After the FRER redundant path startup test is completed, according to the path status table of the FRER replication device shown in Table 1, a preliminary reliability assessment can be performed on all redundant paths of FRER: if the redundant path has Status=None / Fail in Table 1, then the path is faulty; if the redundant path has Status=Success in Table 1, then the path is normal. At the same time, according to the Latency in Table 1, the reliability of the redundant path can be obtained. Figure 3 Delay in the direction of transmission shown.

[0052] After obtaining the preliminary reliability assessment results, you can continue to start the FRER redundant path test. Through the results of multiple tests, you can make an accurate assessment of the reliability of the FRER redundant path. You can also combine the path status table of the FRER elimination device shown in Table 2 to troubleshoot the faulty path, for example:

[0053] If the redundant path has Status=None in Table 1 and Status=None in Table 2, then the path Figure 3 There is a fault in the transmission direction shown. The fault is caused by the risk of packet loss along the path.

[0054] If the redundant path has Status=None in Table 1 and Status=Success in Table 2, then the path Figure 4 There is a fault in the transmission direction shown. The fault is caused by the risk of packet loss along the path.

[0055] If the redundant path has Status=None in Table 1 and Status=Fail in Table 2, then the path Figure 3 and Figure 4 There are faults in all transmission directions shown. Figure 3 The fault in the transmission direction shown may be caused by excessive path delay or the path not supporting the switch delay accumulation function. Figure 4 The fault cause in the transmission direction shown is the risk of packet loss along the path;

[0056] If the redundant path has Status=Fail in Table 1 and Status=Fail in Table 2, then the path Figure 3 A fault exists in the transmission direction. Possible causes include excessive path delay, unstable path delay, or the path not supporting the switching delay accumulation function.

[0057] By starting the detection of the FRER redundant path, the reliability of the FRER redundant path can be evaluated.

[0058] 3. FRER redundant path cycle detection

[0059] When all FRER redundant paths have passed the startup test, all Status = Success in the path status table of the FRER replication device shown in Table 1, and the FRER function can be enabled. While the FRER function is working, first enable the FRER redundant path periodic test on the FRER elimination device, and follow the Figure 8 Then start the FRER redundant path cycle detection on the FRER replication device and follow the Figure 7 The process shown is tested.

[0060] Timer 3 is configured on the FRER replication device, which determines the duration of each periodic detection cycle. When periodic detection is enabled, the FRER replication device first resets the Status in the path status table shown in Table 1 to Fail and the Latency to 0. It then initializes Timer 3 and starts the timer.

[0061] The FRER replication device sends a heartbeat detection message (or periodic detection message) to each redundant path, which can be an SV message or a GOOSE message. Figure 1 and Figure 2 The diagram shows the structure of the message. In the heartbeat detection message, set Test = 0, OVF = 0, Type = 4, PID = Path ID in the path status table shown in Table 1, Reserved = 0, ART = 0; the heartbeat detection message is as follows Figure 3 Transmitted in the direction shown, it reaches the FRER elimination device, Figure 3 The intermediate devices 1 - 4 shown can calculate the transmission delay of the redundant path according to the switching delay accumulation function, and edit the OVF and ART fields of the startup detection message accordingly.

[0062] The FRER elimination device verifies the legitimacy of each received heartbeat probe message. Using the port that received the heartbeat probe message as the port ID, it retrieves the corresponding path ID from the path status table shown in Table 2. If the PID and path ID of the heartbeat probe message do not match, the message is considered invalid and no action is taken. The device waits for the next heartbeat probe message until the cycle detection is closed. If they match, the device proceeds to the next step.

[0063] If the OVF of the heartbeat detection message is equal to 1, according to the switching delay accumulation function, it is considered that there are problems such as excessive delay or intermediate device failure on the redundant path, and the normal operation of the FRER function cannot continue to be satisfied.

[0064] If the OVF of the heartbeat detection message is equal to 0 and the ART is also equal to 0, according to the switching delay accumulation function, it is considered that the redundant path can no longer support switching delay accumulation.

[0065] If the OVF of the heartbeat detection message is equal to 0 and ART is not equal to 0, then according to the exchange delay accumulation function, the transmission delay on the redundant path is converted by the ART value. If the delay is not within a reasonable range, it is considered that congestion or delay instability occurs on the redundant path, and the normal operation of the FRER function cannot continue to be met.

[0066] If the judgment result is one of the above three situations, no processing is performed and the system continues to wait for the next heartbeat detection message until the periodic detection is closed.

[0067] If the OVF of the heartbeat detection message is equal to 0, the ART is not equal to 0, and the delay calculated by the exchange delay accumulation function is within a reasonable range, it is considered that the redundant path can continue to meet the normal operation of the FRER function. Then the FRER elimination device will send a path validation message to the corresponding redundant path, which can be an SV message or a GOOSE message. Figure 1 and Figure 2 The diagram shows the structure of the message. In the path validation message, set Test = 0, OVF = 1, Type = 2, PID = Path ID in the path status table shown in Table 2, Reserved = 0, ART = ART in the heartbeat detection message; the path validation message is as follows Figure 4 Transmitted in the direction shown, it reaches the FRER replication device, and according to the exchange delay accumulation function, Figure 4 The intermediate devices 1-4 shown do not edit the path validation message.

[0068] Before Timer 3 expires, the FRER replica device processes each received Path Validation message. If a Path Validation message is received, the corresponding entry's Status is set to Success. The switch delay accumulation function calculates the latency using the ART in the message and sets the Latency value of the corresponding entry in the path status table shown in Table 1 to that latency.

[0069] At the end of Timer 3, the FRER replica device checks all Status entries in the path status table shown in Table 1. If any entry has Status = Fail, the device reports the failure and includes the Path ID of the failed redundant path, ending the periodic detection. If no entry has Status = Fail, a new round of FRER redundant path periodic detection is automatically initiated. In each round of periodic detection, the latency of all FRER redundant paths is automatically updated, achieving latency measurement.

[0070] 4. Result processing of FRER redundant path cycle detection

[0071] Occurs during cycle detection Figure 7 In the fault reporting situation shown, if all FRER redundant paths fail, the FRER replication device automatically stops the FRER function; if part of the FRER redundant paths fail, the FRER replication device can choose to stop transmitting data to the failed path or choose not to process it.

[0072] Through FRER redundant path periodic detection, real-time fault detection and delay measurement of FRER redundant paths are achieved.

[0073] The key points of the present invention include:

[0074] 1. Figure 2 As shown in the figure, based on the existing SV / GOOSE message structure, new fields Type and PID are defined, thereby defining four new SV / GOOSE message types: startup detection message, path validation message, path failure message, and heartbeat detection message.

[0075] 2. As shown in Table 1, the newly defined path status table configured in the FRER replication device

[0076] 3. As shown in Table 2, the path status table configured in the FRER elimination device is newly defined

[0077] 4. Figure 5 and Figure 6 As shown, the new FRER redundant path startup detection complete process is defined

[0078] 5. Figure 7 and Figure 8 As shown, the complete process of FRER redundant path cycle detection is newly defined

[0079] 6. The FRER redundant path startup detection process in Article 4 flexibly uses the message in Article 1 and the path status table in Articles 2 / 3

[0080] 7. The FRER redundant path cycle detection process in Article 5 flexibly uses the message in Article 1 and the path status table in Articles 2 / 3

[0081] 8. Based on the message in Article 1, the path status table information in Articles 2 / 3 can be updated and maintained

[0082] 9. According to the FRER redundant path startup detection in Article 4, path reliability assessment can be provided for existing FRER technology

[0083] 10. The FRER redundant path cycle detection according to Article 5 can provide real-time fault detection and delay measurement for existing FRER technology, thereby ensuring path reliability, data consistency and deterministic transmission.

[0084] 11. Combined with the FRER redundant path periodic detection in Article 5, the fault path can be automatically shielded during the FRER function operation to flexibly avoid risks.

[0085] The present invention is only applicable to the scenario where there is only one FRER environment in the physical network. If you need to configure multiple FRER scenarios in the physical network at the same time, you can make the following changes:

[0086] Figure 2 In the message field definition shown, the reserved field is defined as FID (FRER Index, FRER sequence number), that is, FRER ID, which represents the identifier of the FRER environment. 0 is FRER environment one and 1 is FRER environment two.

[0087] The path state table shown in Table 1 supports configuring one path state table of Table 1 per FRER environment on a FRER replication device;

[0088] The path state table shown in Table 2 supports configuring one path state table of Table 2 per FRER environment on a FRER elimination device;

[0089] Figure 5 The flowchart shown supports configuring one timer Timer1 per FRER environment on a FRER replication device;

[0090] Figure 6 The flowchart shown supports configuring a timer Timer2 per FRER environment on a FRER elimination device;

[0091] Figure 7 The flowchart shown supports configuring one timer Timer3 per FRER environment on a FRER replication device;

[0092] Figure 5 As shown in the flowchart, the FRER replication device needs to edit the FID when generating the startup detection message; when the FRER replication device receives the path validation message / path failure message, it needs to parse the FID and set the path status table corresponding to the FID;

[0093] Figure 6 As shown in the flowchart, when the FRER elimination device receives the startup detection message, it needs to parse the FID and set the path status table corresponding to the FID; when the FRER elimination device generates the path validation message / path failure message, it needs to edit the FID;

[0094] Figure 7 As shown in the flowchart, the FRER replication device needs to edit the FID when generating a heartbeat detection message; when the FRER replication device receives a path validation message, it needs to parse the FID and set the path status table corresponding to the FID. The fault report needs to carry the FRER environment identifier;

[0095] Figure 8 As shown in the flowchart, when the FRER elimination device receives the heartbeat detection message, it needs to parse the FID; when the FRER elimination device generates the path validation message, it needs to edit the FID.

[0096] The present invention defines Figure 2 The Type field uses values ​​1-4, which consumes 3 bits. A variation on this is that the value can be changed to 0-3, which only consumes 2 bits, saving bits.

[0097] The present invention defines Figure 2 The PID field shown uses 1-2, consuming 2 bits, and supports 2 redundant FRER paths. A variation is as follows: 0-1 can be used, consuming 1 bit, saving bits. Alternatively, the variation on the Type field described in Article 2 can be combined to expand the PID bit to 3, or even expand the PID bit to 4 without using the first FID, thus supporting a FRER environment with a maximum of 15 redundant paths.

[0098] Figure 3 / Figure 4 The number of intermediate switches shown varies depending on the specific FRER environment.

[0099] Obviously, it can be understood that all of the above-mentioned variations should be included in the protection scope of the present invention.

[0100] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for evaluating and detecting redundant FRER paths based on a switching delay accumulation function, characterized in that: The method includes performing a FRER redundant path startup detection before the FRER function is enabled, wherein the FRER redundant path startup detection includes the following steps: S1: The FRER replication device configures a first path status table and a first timer, and sends a startup detection message to each redundant path after starting the first timer. The first path status table includes the redundant path ID, the redundant path connection port ID, the redundant path status, and the message transmission delay. S2: The FRER elimination device configures a second path status table and a second timer, and after starting the second timer, performs a validity judgment on each startup detection message received, and based on the corresponding field value and delay of the received startup detection message, sets the Status of the corresponding entry in the second path status table to Fail and sends a path failure message to the corresponding redundant path, or sets the Status of the corresponding entry to Success and sends a path validation message to the corresponding redundant path. The second path status table includes a redundant path identifier Path ID, a redundant path connection port Port ID, and a redundant path status Status. If the FRER elimination device does not receive any startup detection message when the second timer ends, the FRER elimination device does not perform any processing. S3: If the FRER replica device receives a path failure message before the first timer expires, it sets the Status of the corresponding entry in the first path status table to Fail; if it receives a path validation message, it sets the Status of the corresponding entry to Success, and then calculates and updates the Latency based on the exchange delay accumulation function; if the FRER replica device does not receive any path failure message or path validation message when the first timer expires, the FRER replica device does not perform any processing; wherein, The startup detection message, the path failure message and the path validation message are defined according to the existing SV / GOOSE message structure.

2. The method according to claim 1, characterized in that Also includes: After all FRER redundant paths have passed the FRER redundant path startup detection, the FRER function is started, and while the FRER function is working, the FRER redundant path periodic detection is started, and the FRER redundant path periodic detection includes the following steps: T1: The FRER replication device is configured with a third timer for indicating the duration of each period of periodic detection. In each detection period, the FRER replication device first resets the Status in the first path status table to Fail and resets the Latency to 0. After starting the third timer, the FRER replication device sends a heartbeat detection message to each redundant path. The heartbeat detection message is defined according to the existing SV / GOOSE message structure. T2: The FRER elimination device receives a heartbeat detection message during each detection cycle. If the received heartbeat detection message is legal and the corresponding field value and delay of the heartbeat detection message meet certain conditions, it sends a path validation message to the corresponding redundant path; otherwise, no processing is performed and the device continues to wait for the next heartbeat detection message until the cycle detection is closed. T3: If the FRER replica device receives a path validation message before the third timer expires, it sets the Status of the corresponding entry in the first path status table to Success and updates the Latency based on the exchange delay accumulation function. T4: At the end of the third timer, the FRER replication device checks all Status in the first path status table. If Status = Fail, it reports the fault and carries the Path ID of the failed redundant path, and then ends the cycle detection; if Status = Fail does not exist, a new round of FRER redundant path cycle detection is automatically started.

3. The method according to claim 2, characterized in that The switch delay accumulation function uses reserved fields in the SV / GOOSE message. These reserved fields include the test mode flag Test, overflow flag OVF, type field Type, path identifier field PID, reserved bits, and application reference time ART. Different message types are defined by configuring the Type value.

4. The method according to claim 3, characterized in that In step S2, the legitimacy of the startup probe message is judged, including: using the port that received the startup probe message as the Port ID, retrieving the corresponding Path ID in the second path status table; if the PID and Path ID of the startup probe message are inconsistent, the message is considered invalid and no processing is performed, and the next startup probe message is continued to be waited until the second timer expires; if they are consistent, the next judgment is continued.

5. The method according to claim 4, characterized in that In step S2, under the following circumstances, the Status of the corresponding entry in the second path status table is set to Fail, and a path failure message is sent to the corresponding redundant path: (1) If the OVF of the start-up detection message is equal to 1, according to the switching delay accumulation function, it is considered that the corresponding redundant path cannot meet the normal operation of the FRER function; (2) If the OVF of the start-up detection message is equal to 0 and the ART is also equal to 0, according to the switching delay accumulation function, it is considered that the switching delay accumulation is not supported on the corresponding redundant path; (3) If the OVF of the start-up probe message is equal to 0 and ART is not equal to 0, the transmission delay on the redundant path is converted by the value of ART according to the exchange delay accumulation function. If the delay is not within a reasonable range, it is considered that the corresponding redundant path cannot meet the normal operation of the FRER function.

6. The method according to claim 5, characterized in that In step S2, under the following circumstances, the Status of the corresponding entry in the second path status table is set to Success, and a path validation message is sent to the corresponding redundant path: If the OVF of the startup probe message is equal to 0, the ART is not equal to 0, and the delay calculated by the switching delay accumulation function is within a reasonable range, it is considered that the redundant path can meet the normal operation of the FRER function.

7. The method according to claim 6, characterized in that The method further comprises: S4: Based on the first path status table and in combination with the second path status table, the reliability of the FRER redundant path is evaluated, where (1) If Status=None in the first path status table and Status=None in the second path status table, then the corresponding redundant path has a fault in the transmission direction from the FRER replication device to the FRER elimination device. The cause of the fault is the risk of packet loss on the path. (2) If Status=None in the first path status table and Status=Success in the second path status table, then the corresponding redundant path has a fault in the transmission direction from the FRER elimination device to the FRER replication device. The cause of the fault is the risk of packet loss on the path. (3) If Status=None in the first path status table and Status=Fail in the second path status table, then the corresponding redundant path has faults in both transmission directions. The cause of the fault in the transmission direction from the FRER replication device to the FRER elimination device includes excessive path delay or the path does not support the switching delay accumulation function. The cause of the fault in the transmission direction from the FRER elimination device to the FRER replication device is the risk of packet loss on the path. (4) If Status = Fail in the first path status table and Status = Fail in the second path status table, then the corresponding redundant path has a fault in the transmission direction from the FRER replication device to the FRER elimination device. The causes of the fault include excessive path delay, unstable path delay, and the path not supporting the switching delay accumulation function.

8. The method according to claim 7, characterized in that In step T2, a path validation message is sent to the corresponding redundant path in the following situations: If the OVF of the heartbeat detection message is equal to 0, the ART is not equal to 0, and the delay converted by the switching delay accumulation function is within a reasonable range, it is considered that the corresponding redundant path can continue to meet the normal operation of the FRER function.

9. The method according to claim 8, characterized in that In step T2, in the following cases, no processing is performed and the system continues to wait for the next heartbeat detection message until the periodic detection is closed: (1) If the OVF of the heartbeat detection message is equal to 1, according to the switching delay accumulation function, it is considered that there is a large delay or an intermediate device failure on the corresponding redundant path, and the normal operation of the FRER function cannot continue to be met; (2) If the OVF of the heartbeat detection message is equal to 0 and the ART is also equal to 0, according to the switching delay accumulation function, it is considered that the corresponding redundant path can no longer support switching delay accumulation; (3) If the OVF of the heartbeat detection message is equal to 0 and ART is not equal to 0, the transmission delay on the redundant path is converted by the value of ART according to the exchange delay accumulation function. If the delay is not within a reasonable range, it is considered that congestion or delay instability occurs on the corresponding redundant path, and the normal operation of the FRER function cannot continue to be met.

10. The method according to claim 9, characterized in that In step T4, if all FRER redundant paths fail, the FRER replication device automatically stops the FRER function; if part of the FRER redundant paths fail, the FRER replication device chooses to stop transmitting data to the failed path or chooses not to process.

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