KR20190124314A - Protective switching method and apparatus for ring networks - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to the field of communications, and discloses a method and apparatus for protection switching for a ring network. The protection switching method and apparatus for a ring network of the present invention is to solve the conventional technical problem that can not implement the corresponding service protection due to the SD situation such as disconnection, error frame in the link. The method comprises the steps of: respectively detecting whether signal degradation has occurred in the link by an end node of the link; And when a signal degradation occurs in the link, performing a corresponding protection switching operation by a corresponding node.

Description

Protective switching method and apparatus for ring networks

TECHNICAL FIELD The present invention relates to the field of communications technology, and more particularly, to a protection switching method and apparatus for a ring network.

The ring network protection protocols (ERPS) and switching mechanism (g.8032) of Ethernet transport networks implement fast (<50ms) protection switching of Ethernet ring topology services.

However, current ERPS only implements a protection switching trigger mechanism that triggers a signal fail (SF) such as port down, fiber disconnect, etc. There is a problem in that corresponding service protection cannot be implemented in SD (signal degrade) situations such as blockage and error frames.

Accordingly, an object of the present invention is to provide a protection switching method and apparatus for a ring network in order to solve the problems of the prior art in which a corresponding service protection cannot be implemented due to the SD situation such as a link disconnection or an error frame.

In one aspect, the protection switching method for a ring network of the present invention comprises: detecting whether signal degradation has occurred in a link by an end node of the link, respectively; And when a signal degradation occurs in the link, performing a corresponding protection switching operation by a corresponding node.

Optionally, each detecting whether a signal degradation has occurred in a link by an end node of the link comprises receiving a ring network link state monitoring message from a link operation administration maintenance (oam), respectively, by the end node of the link. The ring network link state monitoring message conveying a frame event parameter; And determining, by the end node, whether signal degradation of the link occurs according to the frame event parameter.

Optionally, prior to detecting whether a signal degradation has occurred on the link by the end node of the link due to signal failure, respectively, the method further comprises: a ring network protection state machine and a ring network protection protocol message being processed for the signal degradation. Adding a processing mechanism for signal degradation in the ring network protection state machine upon signal failure and modifying the request / status bit value of the ring network protection protocol message upon signal failure to be compatible.

Optionally, adding a handling mechanism for signal degradation in a ring network protection state machine upon signal failure and modifying the request / status bit value of a ring network protection protocol message upon signal failure, the ring network protection request / state Adding a local signal degradation (local SD) entry, a local clear SD entry, and a ring network auto-protection switching (R-APS-SD) entry according to the signal degradation to a priority list, wherein In the R-APS-SD item, if the current end node is in the local SD state, the current end node informs the neighboring node that the current link is in a signal degradation state through the ring network protection protocol message after modification, The corresponding request / status bit value in the ring network protection protocol message indicates a signal degradation state.

Optionally, the frame event parameter comprises at least one of an error symbol event parameter, an error frame event parameter, an error frame cycle event parameter, and an error frame second aggregate event parameter.

Optionally, determining, according to the frame event parameter, whether a signal degradation has occurred in a ring network, when the cumulative number of occurrences of a frame event within a predetermined time exceeds a predetermined event threshold. Determining that signal degradation has occurred.

The method may further include establishing at least one ring network protection instance on the ring network before receiving a ring network link state monitoring message of the link oam (link operation administration maintenance). And receiving a registration message of each ring network protection instance, wherein the registration message further includes delivering a corresponding ring network protection instance indication.

Optionally, when signal degradation occurs in the ring network, the corresponding protection switching operation performed by the corresponding ring network node indicates a signal degradation indication to the corresponding ring network protection instance when signal degradation occurs in the ring network. Transmitting; And performing a corresponding protection switching operation according to different ring network protection instances.

In addition, if a signal degradation occurs in the ring network, after performing a corresponding protection switching operation by a corresponding ring network node, the method continues to receive a ring network link state monitoring message from a link oam, wherein the ring The network link status monitoring message may include delivering a frame event parameter; Each ring network node determining a ring network signal quality indicator according to the frame event parameter; And when the ring network signal quality indicator is higher than a predetermined restoration threshold, restoring the ring network that has performed the protection switching operation to the initial ring network.

Optionally, each detecting whether a signal degradation has occurred in the link by an end node of the link includes determining whether signal degradation has occurred in the link by detecting attenuation of a laser signal.

On the other side, the present invention is a detection unit for detecting whether or not a signal degradation occurred in the link by the end node of the link; And a protection switching unit configured to perform a corresponding protection switching operation by the corresponding node when a signal degradation occurs in the link.

Optionally, the detection unit comprises: a receiving module for receiving ring network link state monitoring messages from the link oam, respectively, by the end node of the link, the ring network link state monitoring messages passing frame event parameters; And a determination module for determining whether signal degradation occurs in the link according to the frame event parameter at the end node.

Optionally, the apparatus fails the signal so that a ring network protection state machine and a ring network protection protocol message are compatible with the processing for signal degradation before each detecting whether a signal degradation has occurred on the link by an end node of the link. And a modification for adding a processing mechanism for signal degradation in the ring network protection state machine according to the above and correcting a request / status bit value of a message of the ring network protection protocol according to the signal failure.

Optionally, the modifying unit may further include a local SD signal, a local clear SD item, and a ring network auto-protection switch according to the signal degradation in the ring network protection request / status priority list. R-APS-SD) item, wherein the R-APS-SD item is used when the current end node is in the local SD state. Informing the neighboring node that the current link is in a signal degradation state, a corresponding request / status bit value in the ring network protection protocol message indicates a signal degradation state.

Optionally, the frame event parameter includes at least one of an error symbol event parameter, an error frame event parameter, an error frame cycle event parameter, and an error frame second aggregate event parameter.

Optionally, the determination module is specifically used to determine that signal degradation has occurred in the ring network when the number of occurrences of a frame event within a predetermined time exceeds a predetermined event threshold.

The apparatus further includes a setting unit for setting at least one ring network protection instance on the ring network before receiving a ring network link state monitoring message from a link oam; And a registration unit for receiving a registration message of each ring network protection instance set by the setting unit, wherein the registration message transmits a corresponding ring network protection instance mark.

Optionally, the protection switching unit specifically sends a signal degradation indication to a corresponding ring network protection instance when signal degradation occurs in the ring network; And to perform corresponding protection switching operations according to different ring network protection examples.

Optionally, the apparatus further comprises a restoring unit, and in case the signal degradation occurs in the ring network, the receiving module performs a corresponding protection switching operation by a corresponding ring network node, and then performs a ring network link state from the link oam. Continue to receive the monitoring message, wherein the ring network link state monitoring message is further used to convey frame event parameters; The determining module is further used to determine a ring network signal quality indicator according to the frame event parameter; The restoration unit is used to restore the ring network that has performed the protection switching operation to the initial ring network when the ring network signal quality indicator is higher than a predetermined restoration threshold.

The protection switching method and apparatus for a ring network provided in an embodiment of the present invention can detect whether a signal degradation has occurred in a link by an end node of the link; When signal degradation occurs in the ring network, a corresponding ring network node performs a corresponding protection switching operation to perform communication and service using a node and a link having a good signal. In this way, the ring network is determined by the end node of the link whether the signal quality is determined by whether there is a signal degradation situation such as a disconnection or an error frame on the link, and at the same time, when a signal degradation situation occurs, a protection switching operation is performed correspondingly. Effectively improve link performance.

1 is a flowchart of a protection switching method for a ring network according to an embodiment of the present invention.
2 is a structural schematic diagram of a ring network according to an embodiment of the present invention.
3 is a structural schematic diagram of a ring network node according to an embodiment of the present invention.
4 is another structural schematic diagram of a ring network protection example according to an embodiment of the present invention.
5 is a schematic diagram of notifying ring network protection when an SD occurs in a link according to an embodiment of the present invention.
6 is a schematic diagram of ring network protection performing protection switching after receiving an SD occurrence message of a link according to an embodiment of the present invention.
7 is a schematic diagram of notifying ring network protection after restoration of a lost SD in a link according to an embodiment of the present invention.
8 is a structural schematic diagram of a protection switching device for a ring network according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the specific embodiments described herein are for interpreting the present invention, but the scope of the present invention is not limited by the following examples.

As shown in FIG. 1, a protection switching method for a ring network according to an exemplary embodiment of the present invention is provided.

Detecting whether signal degradation has occurred in the link at an end node of the link; And

And if signal degradation occurs in the link, step S12 of performing a corresponding protection switching operation by a corresponding node.

The protection switching method for a ring network provided by an embodiment of the present invention can detect whether a signal degradation has occurred in a link at an end node of the link; When signal degradation occurs in the ring network, a corresponding ring network node performs a corresponding protection switching operation to perform communication and service using a node and a link having a good signal. In this way, the signal is determined by the end node of the link whether there is a signal degradation situation such as disconnection or error frame on the link, and at the same time, if a signal degradation situation occurs, a corresponding protection switching operation is performed to perform a ring network link. Improve performance effectively.

Optionally, in step S11, it is determined whether signal degradation has occurred in the link, for example, by detecting attenuation of a laser signal, or whether signal degradation has occurred in the link through a ring network link status monitoring message from a link oam. The signal degradation of the link may be detected by various methods, such as determining. Embodiments according to the invention are not limited thereto.

Specifically, step S11 for detecting whether signal degradation has occurred in the link by the end node of the link,

Receiving, by the end node of the link, a ring network link state monitoring message from the link oam, respectively, the ring network link state monitoring message passing a frame event parameter; And

The end node may further include determining whether a signal degradation of a ring network occurs according to the frame event parameter.

In this manner, each link end node may each receive a ring network link state monitoring message from the link oam to determine whether signal degradation of the ring network occurs according to the frame event parameter conveyed by the ring network link state monitoring message; When signal degradation occurs in the ring network, a corresponding protection switching operation is performed by a corresponding node to perform communication and service using a node and a link having a good signal. In this way, the link oam can perform link manipulation, monitoring, and error positioning at the data link layer, and the end nodes of each link can degrade signals such as disconnection and error frames on the link according to the frame event parameters provided by the link oam. Whether there is a situation can be determined whether the signal quality, and at the same time, if a signal degradation situation occurs, a corresponding protective switching operation can be performed.

In a specific implementation, one ring network may have multiple nodes, and each node may perform state monitoring on the node itself and on the link directly connected to the node via the link oam. Optionally, in step S11, the frame event parameter conveyed by the ring network link state monitoring message includes at least one or more of an error symbol event parameter, an error frame event parameter, an error frame cycle event parameter, and an error frame second aggregation event parameter, Link end nodes can achieve the goal of monitoring link performance in real time by monitoring these frame event parameters.

According to a specific situation and request, the user may select one of the frame event parameters to reflect the link performance, or may use the combination of several frame events to reflect the link performance. Embodiments of the present invention are not limited in this regard.

For example, in one embodiment according to the present invention, the end node of the link determines whether the link performance is good or whether signal degradation has occurred in the link based on an error frame event parameter. Specifically, if the number of times link oam receives an error frame (RxErroredFrame) within the window monitoring cycle exceeds the prescribed error threshold (ErrThreshold), it is determined that an error frame event (ErrFrameEvent) has occurred on the link. In the event window and indicates that an error frame event occurred once.

That is, if RxErroredFrame≥ErrThreshold within Window monitoring time,

ErrFrameEvent = RxErroredFrame / ErrThreshold.

Optionally, it may be determined whether signal degradation has occurred in the ring network according to the frame event parameter conveyed by the ring network link state monitoring message. Specific determination methods and criteria for determining whether a signal is degraded may vary, and embodiments according to the present invention are not limited thereto. For example, in an embodiment of the present disclosure, when the cumulative number of occurrences of a frame event exceeds a predetermined event threshold within a predetermined time, it may be determined that signal degradation has occurred in the ring network.

In a specific embodiment, first, the cumulative time of the frame event parameter, that is, the cumulative time for how long the cumulative occurrence of the frame event is counted within a long time range may be set. Optionally, since link oam performs frame event monitoring within different monitoring windows, the corresponding cumulative time can be set by setting the number of windows (N).

Optionally, it may also be set for a predetermined event threshold value EvThresholdMax. When the cumulative number of frame events (ie, ring network performance indicators) ErrPef within t ≦ N * Window time is greater than a predetermined event threshold value EvThresholdMax, it may be determined that signal degradation has occurred in the ring network. Similarly, taking an error frame event as an example,

ErrPef + = ErrFrameEvent within the time of t≤N * Window;

If ErrPef ≥ EvThresholdMax, it is assumed that signal degradation has occurred on the link.

The above embodiment has described how to determine whether signal degradation occurs by using a frame event parameter as an error frame event parameter. However, the present invention is not limited thereto. Frame event parameters, such as error symbol event parameters, error frame cycle event parameters, and error frame second aggregate event parameters, can be derived according to a similar principle, and only need to replace corresponding parameters. For example, in another embodiment according to the present invention, the RxErroredFrame of the present embodiment may be replaced with RxErroredSymbol (which indicates the number of error symbols received in a cycle), and the corresponding frame event may be replaced with an error symbol event. . Various threshold values corresponding to different frame events may be adjusted as needed, and these threshold values may be the same or different from each other, and embodiments of the present invention are not limited thereto.

Correspondingly, with respect to the relationship between the number of frame event occurrences and a predetermined event threshold value, each can be aggregated according to different event types, and different types of frame events can be combined according to certain rules. For example, different types of frame events can be represented in one logical relationship and aggregated according to the logical relationship. For example, in one embodiment according to the present invention, since the ring network is most sensitive to the error frame cycle event ErrFramePeriodEvent and relatively sensitive to the error frame second cumulative event ErrFrameSecsSummaryEvent, a logical relationship can be established based on this. In other words,

ErrPef + = 3ErrFramePeriodEvent + ErrFrameSecs SummaryEvent

In this way, if the number of occurrences of ErrFrameSecsSummaryEvent is relatively high, the ErrPef increase is relatively fast and once the threshold is exceeded, the loop can immediately perform protection switching.

It should be noted that, since ring network protection also performs switching or restoration upon the creation or loss of link SF, when SF (signal failure) or SD (signal degradation) occurs on the link, the ring network all switches off. Only if both SF and SD disappear, the ring network can perform a restore. Since there is no SD processing mechanism in the existing ring network state machine, the embodiment according to the present invention should modify the ring network protection state machine with the processing mechanism for SD.

Specifically, in one embodiment according to the present invention, before each detecting whether a signal degradation has occurred on the link by an end node of the link, the method may further include a ring network protection state machine and a ring network protection protocol message. Adding a processing mechanism for signal degradation in the ring network protection state machine upon signal failure and modifying the request / status bit value of the message of the ring network protection protocol upon signal failure in order to be compatible with processing for signal degradation. It includes more.

According to a specific embodiment, a local network signal degradation (local SD) item, a local clear signal SD (local clear SD) item and ring network auto-protection switching according to signal degradation (R-APS-) in the ring network protection request / status priority list. SD) item can be added; In this case, the R-APS-SD item indicates that when the current end node is in the local SD state, the current end node informs an adjacent node that the current link is in a signal degradation state through the ring network protection protocol message after modification. Where the corresponding request / status bit value in the ring network protection protocol message indicates a signal degradation state.

Optionally, the ring network protection request / state priority after modification is as shown in Table 1 below.

Request / status type Priority Clear local Best FS local Gradually down R-APS (FS) remote Gradually down local SF local Gradually down local clear SF local Gradually down local SD (remarks) local Gradually down local clear SD (Remarks) local Gradually down R-APS (SF) remote Gradually down R-APS-SD (Remarks) remote Gradually down R-APS (MS) remote Gradually down MS local Gradually down WTR expire local Gradually down WTR running local Gradually down WTB expire local Gradually down WTB running local Gradually down R-APS (NR, RB) remote Gradually down R-APS (NR remote lowest Remarks: SD processing addition

Ring network protection protocol message request / status bit values are shown in Table 2. When the current end node is in the local SD state, the current end node uses the corresponding request / status bit value of the ring network protection protocol messages in Table 2 as the signal degradation state (i.e. 1010) to adjoin the ring network protection protocol message. It transmits to a node to inform neighboring nodes that the current link is in a signal degradation state.

area value Explanation Request / status 1101 Forced Switch (FS) 1110 Event 1011 Signal Fail (SF) 1010 Signal Degrade (SD) 0111 Manual Switch (MS) 0000 No Request (NR) Other Hold

Specifically, when signal degradation occurs, the corresponding node performs a specific protection switching operation to block both ends of the link where signal degradation occurs, and sends an R_SF message to protect when other nodes show a problem in link protection. Inform to perform switching. The RPL master node and the RPL neighbor node can change the transmission path of the link signal by changing both ends of the RPL link to the forward state.

This embodiment has described the overall situation of performing protective switching after signal degradation occurs in a ring network. In addition, in the physical architecture of the same ring network, it is possible to support a plurality of logically different ring network instances, and to implement corresponding services in corresponding ring network instances. As shown in FIG. 2, in one embodiment according to the present invention, one ring network instance is constructed in a ring network consisting of four nodes A, B, C, and D. FIG. Where A is the master node and D is an adjacent node. The link between ADs is an RPL backup link. There are two services in the ring network example: traffic1 and traffic2. In another embodiment of the present invention, the ring network may establish another ring network instance with other master nodes and corresponding backup links, and embodiments according to the present invention are not limited in this regard.

When establishing a ring network protection instance on a ring network, before each receiving of the ring network link state monitoring message from the link oam by the end node of the link, the protection switching method for the ring network of the embodiment according to the present invention,

Establishing at least one ring network protection instance on the ring network; And

Receiving a registration message of each ring network protection instance, the registration message may further include delivering a corresponding ring network protection instance indication.

Optionally, the registration message of the ring network protection instance includes the content as indicated in Table 3.

Msg-type (1 byte) value (1byte) SD-process (module id = 15) Erps-id (1-32)

As indicated in Table 3, the first row is the item name and the second row is the corresponding value. SD-process (module id id = 15) is the module number of the signal degradation detection process, and Erps-id (1 to 32) is the ring network protection instance number. That is, the ring network protection instance numbers 1 to 32 are informed to the signal detection module whose signal degradation detection step module number is 15.

Based on this, the corresponding protection switching operation performed by the corresponding node when the signal degradation occurs in the ring network in step S13, specifically,

When a signal signaling occurs in the ring network, transmitting a signal degradation indication to a corresponding ring network protection instance; And

And performing a corresponding protection switching operation according to different ring network protection instances.

Optionally, the signal degradation indication sent to the corresponding ring network protection instance may include the content shown in Table 4, which is specifically used to indicate in which ring network a signal degradation has occurred. For example, if three different ring network protection instances A1, A2, and A3 are configured on one physical ring network, if signal degradation occurs in the ring network protection instances corresponding to A1 and A3, ring network protection The signal degradation indication can be sent to the instances A1 and A3, respectively, which carries the ring network protection instance number and the signal degradation indication character (SD-state). Correspondingly, after ring signal protection examples A1 and A3 receive a signal degradation indication, they block both ends of the link where signal degradation occurs, respectively, and the RPL master node and the RPL neighbor node forward both ends of the RPL link. It is possible to change the transmission path of the link signal by changing to.

Msg-type (1 byte) Erps-id (1 byte) SD-state (1 byte) erps (module id = 12) 1 to 32 1 (SD) / 0 (SD clear)

As indicated in Table 4, the first row is the item name and the second row is the corresponding value. erps (module id = 12) is a ring network protection module number, 1 to 32 are ring network protection instance numbers, and 1 (SD) / 0 (SD clear) indicates whether signal degradation has occurred.

Further, when signal degradation occurs in the ring network, after performing a corresponding protection switching operation by a corresponding ring network node, the protection switching method for a ring network according to the embodiment of the present invention,

Continuing to receive a ring network link state monitoring message from a link oam, the ring network link state monitoring message passing a frame event parameter;

Each link end node determining a ring network signal quality indicator according to the frame event parameter; And

And when the ring network signal quality indicator is higher than a predetermined restoration threshold, restoring the ring network that has performed the protection switching operation to the initial ring network.

That is, in the case of a ring network that has already performed protection switching, the trusted link may be a backup link or an initial link. If the trusted link is the initial link, the signal quality on the initial link can be continuously monitored, and after the signal quality on the initial link is restored, the ring network that has performed the protection switching operation can be restored to the initial ring network to recover the initial ring network. You can continue to use it.

In addition, in the above-described embodiment, even after the protection switching or switching restoration is performed in the ring network, the network manager may report the link in which the SD is created or lost to comprehensively analyze and improve the link node and the overall situation of the link. .

Hereinafter, the protection switching method for a ring network of the present invention will be described in detail with reference to specific examples.

First of all, a node according to the protection switching method for a ring network provided in this embodiment will be briefly described. The node of the communication class Ethernet service of this embodiment is

A. linkoam link monitoring unit;

B. ring network protection switching unit; And

C. link performance calculation and alert processing.

Here, the link performance calculation and alarm processing unit acquires link state information data from the linkoam link monitoring unit, and determines whether to inform the ring network protection switching unit of the SD generation or loss after calculation, and again, the ring network protection switching unit. Protection switching can be performed at

The association of the three is a one-to-one relationship between link performance calculation and alert processing and linkoam link monitoring. Since one or more ring network protection instances can be set up on a single ring network node and the link performance calculation and alert processing must be informed of the current link SD status of the ring network instance, the link performance calculation and alert processing must be The "ring network instance number" shall be notified. The associations of the three of the corresponding one or more ring network instances are shown in Tables 3 (a) and 3 (b).

<Example 1>

Ring network protection switching trigger due to SD generation

In this embodiment, one ring network protection instance configuration is taken as an example, and attention is paid only to the creation and loss of the link SD. Since generation and loss of SF is not the focus of the present invention, not all links of the default protection group generate SF.

Step S21: Establish an Ethernet ring network protection group and add services that require protection to the protection group.

In a specific implementation, four nodes in a ring topology establish an Ethernet ring network protection group. A ring protection link (RPL) link and an RPL master node A and an RPL neighbor node D are set, and both ends of the RPL are in a block state and the network is prevented from forming a ring. Add two services that require protection to the ring network protection group. After the ring network is powered up, the master node A sends an R_NR_RB message to inform the other nodes that the RPL has been blocked so that all nodes enter idle state. The service is transmitted as shown in FIG. For example, the transmission path of traffic 2 is A-B-C-D.

Step S22: After the ring network protection group is established, as shown in FIG. 4, the linkoam protocol is automatically executed on two terminals, east and west of four protection group nodes, to monitor the performance of the corresponding working link.

In a specific implementation, the link event includes an error symbol event, an error frame event, an error frame cycle event, and an error frame second cumulative event, and may accomplish the purpose of monitoring link performance in real time. The user may reflect the performance parameter index of the link using various event combinations according to one or the actual situation.

For example, an error frame event

An error frame event (ErrFrameEvent) is considered to occur on the link when the number of times an error frame (RxErroredFrame) has been received within the window monitoring cycle exceeds the specified performance threshold.

If RxErroredFrame≥Threshold within Window monitoring time,

ErrFrameEvent = RxErroredFrame / Threshold.

In step S23, the link performance calculation and alarm processing unit is driven to record the number of error frame events shown on the link. As shown in FIG. 5, if the performance of the link A-B is monitored to be lower than a predetermined performance criterion, the SD is regarded as appearing on the link A-B and notified to the ring network protection group.

In a specific implementation, in order to drive the link performance calculation and alarm processing unit, the number N of window monitoring cycles and the event occurrence count performance threshold value PefThresholdMax must be set.

For example, an error frame event:

within the time of t≤N * Window,

ErrPef + = ErrFrameEvent;

If ErrPef≥PefThresholdMax, it is assumed that SD has occurred on the link.

Step S24: Nodes A and B of the ring network protection group receive the SD message and then perform corresponding protection switching. Blocks across the link where the SD appears, and sends an R_SF message to tell other nodes to perform protection switching if a problem occurs on the protected link. The RPL master node A and the RPL neighbor node D change both ends of the RPL link to the forward state. After performing protection switching, the service transmits as shown in FIG. For example, the transmission path of traffic 2 is A-D.

<Example 2>

Ring network protection switching restore trigger due to SD loss

In this embodiment, one ring network protection instance configuration is taken as an example, and attention is paid only to the creation and loss of the link SD. Since generation and loss of SF is not the focus of the present invention, not all links of the default protection group generate SF.

Step S31: The Ethernet ring network protection group is established and the link A-B has created the SD and is in the protection switching state.

In a specific implementation, it blocks both ends of the link where the SD appears, and sends an R_SF message to inform other nodes to perform protection switching when a problem occurs on the protection link. The RPL master node and the RPL neighbor node change both ends of the RPL link to the forward state. After performing protection switching, the service transmits as shown in Fig. 6 (5). For example, the transmission path of traffic 2 is A-D.

Step S32: After the ring network protection group is established, the linkoam protocol is automatically executed on the east and west terminals of four protection group nodes to monitor the performance of the working link.

In a specific implementation, the link event includes an error symbol event, an error frame event, an error frame cycle event, and an error frame second cumulative event, which can achieve the purpose of monitoring link performance in real time. The user may reflect the performance parameter index of the link using various event combinations according to one or the actual situation.

For example, an error frame event

When the number of times an error frame (RxErroredFrame) is received within the window monitoring cycle exceeds the specified performance threshold, it is assumed that an error frame event (ErrFrameEvent) has occurred on the link.

That is, if RxErroredFrame≥Threshold within Window monitoring time,

ErrFrameEvent = RxErroredFrame / Threshold.

In step S33, the link performance calculation and alarm processing unit is driven to record the number of error frame events shown in the link. As shown in FIG. 7, if the performance of the link is monitored to be lower than a predetermined performance criterion, the link is considered to have lost SD and notified to the ring network protection group.

In a specific implementation, in order to drive the link performance calculation and alert processing unit, the number N of window monitoring cycles and the event occurrence count performance threshold value ThresholdMin must be set.

within the time of t≥N * Window,

ErrPef + = ErrFrameEvent;

If ErrPefPef≤ThresholdMin, the link is considered to have lost SD.

In step S34, the ring network protection group nodes A and B perform a corresponding switching restoration after receiving the SD loss message. The RPL master node A starts a wait to restore (WTR) timer, and if the WTR times out, blocks the RPL terminal, sends an R_NR_RB message, and changes the SD loss terminal to the forward state. The RPL neighbor node D blocks the RPL terminal after receiving the R_NR_RB message. After Node B receives the R_NR_RB message, it transitions the SD loss terminal to the forward state. After performing the switching restoration, the service is transmitted as shown in FIG.

Here, the linkoam link performance monitoring unit includes a data acquisition module, a data calculation module, and a determination module, wherein. The data collection module is used to obtain performance data of any one of the protected links; The data calculation module is used to calculate the performance of the working link according to the performance data of the link; The decision module is used to determine whether SD is created or lost in the performance of the link.

Hereinafter, protection switching and restoration will be described in detail taking an example of measuring a link performance by an error symbol event.

Set: ErrSymbolWindow = 60 (s),

ErrSymbolThreshold = 1000, PefThresholdMax = 8, PefThresholdMin = 2, N = 10;

Collect performance data: RxErroredSymbol;

Calculate performance data: if RxErroredSymbol ≥ ErrSymbolThreshold;

ErrSymbolEvent = RxErroredSymbol / ErrSymbolThreshold;

ErrPef + = ErrSymbolEvent;

Window = N * ErrSymbolWindow.

Performance Indicators: If ErrPef ≥ PefThresholdMax in Window, it indicates that an SD has been created and tells the ring network protection node to perform protection switching. When the window is exceeded, if ErrPeft≤PefThresholdMin, the link is considered to have lost SD, informing the ring network protection node to perform a switch recovery.

The above-described embodiment has described a method of determining whether signal degradation or signal degradation has been lost, taking the frame event parameter as an error frame event parameter and an error symbol event parameter as an example. However, the present invention is not limited to this. Frame event parameters, such as error frame cycle event parameters and error frame super aggregate event parameters, can likewise be obtained according to similar principles and need only replace corresponding parameters. Various threshold values corresponding to different frame events may be adjusted according to demand, and may be the same or different from each other. Embodiments of the present invention are not limited in this regard.

Correspondingly, the embodiment according to the invention as shown in Figure 8,

A detector 81 which detects whether signal degradation has occurred in the link at the end node of the link; And

In the case where signal degradation occurs in the link, a protection switching device for a ring network further includes a protection switching unit 82 that performs a corresponding protection switching operation by a corresponding node.

The protection switching device for a network provided in the embodiment of the present invention can detect whether signal degradation has occurred in the link by an end node of the link; When signal degradation occurs in the ring network, the corresponding ring network node may perform a corresponding protection switching operation to perform communication and service using a node and a link having a good signal. In this way, whether the signal quality is determined by the end node of the link, whether there is a signal degradation situation such as disconnection or an error frame on the link, and if a signal degradation situation occurs, a corresponding protection switching operation is performed to improve ring network link performance. Can be effectively improved.

Optionally, the detection unit,

A receiving module, each receiving a ring network link state monitoring message from the link oam by an end node of the link, the ring network link state monitoring message passing a frame event parameter; And

And determining, by the end node, whether or not signal degradation occurs in the link according to the frame event parameter.

In this way, the link oam performs link operation, monitoring, and error positioning at the data link layer so that each ring network node has a signal degradation condition such as disconnection or error frame on the ring network according to the frame event parameter provided by the link oam. Determine whether the signal quality through, and if a signal degradation situation occurs, and performs a corresponding protection switching operation.

Optionally, the apparatus fails the signal so that a ring network protection state machine and a ring network protection protocol message are compatible with the processing for signal degradation before each detecting whether a signal degradation has occurred on the link by an end node of the link. And a modification for adding a processing mechanism for signal degradation in the ring network protection state machine according to the above and correcting a request / status bit value of a message of the ring network protection protocol according to the signal failure.

Optionally, the modifying unit may further include a local SD signal, a local clear SD item, and a ring network auto-protection switch according to the signal degradation in the ring network protection request / status priority list. R-APS-SD) is used to add items; Wherein the R-APS-SD-item indicates that when the current end node is in the local SD state, the current end node transmits to the adjacent node that the current link is in a signal degradation state through the ring network protection protocol message after modification. Where the corresponding request / status bit value in the ring network protection protocol message indicates a signal degradation state.

Optionally, the frame event parameter includes at least one of an error symbol event parameter, an error frame event parameter, an error frame cycle event parameter, and an error frame second aggregate event parameter.

Optionally, a determination module is specifically used to determine that signal degradation has occurred in the ring network when the cumulative number of occurrences of the frame event exceeds a predetermined event threshold.

In addition, the protection switching device for a ring network according to an embodiment of the present invention,

A setting unit for setting at least one ring network protection instance on the ring network before receiving a ring network link state monitoring message from a link oam; And

Receiving a registration message of each ring network protection instance set by the setting unit, wherein the registration message may further include a registration unit for transmitting a corresponding ring network protection instance indication.

Optionally, the protection switching unit 82 specifically sends a signal degradation indication to a corresponding ring network protection instance when signal degradation occurs in the ring network; It can be used to perform corresponding protection switching operations according to different ring network protection examples.

In addition, the protection switching device for a ring network according to an embodiment of the present invention may further include a recovery unit. Here, when a signal degradation occurs in the ring network, the receiving module performs a corresponding protection switching operation by a corresponding ring network node, and then continuously receives a ring network link state monitoring message from a link oam, and the ring network link The status monitoring message can be further used to convey frame event parameters;

The determining module may further be used to determine a ring network signal quality indicator according to the frame event parameter;

The restoration unit may be used to restore the ring network that has performed the protection switching operation to the initial ring network when the ring network signal quality indicator is higher than a predetermined restoration threshold.

Optionally, the detector 81 is used to determine whether signal degradation has occurred in the link, specifically by detecting attenuation of the laser signal.

As used herein, the terms “comprise,” “comprise,” or other variations of these terms encompass non-exclusive inclusion, and therefore, a process, method, article, or apparatus of a series of components may include such components. As well as other elements not explicitly listed, or elements specific to such processes, methods, articles or devices. In the absence of further limitations, an element defined as "comprising a" does not exclude including the process, method, article of the element, or any additional equivalent elements present in the device.

Through the description of the above embodiments, those skilled in the art can clearly realize that the method of the above-described embodiments can be implemented by adding a general-purpose hardware platform required for software, and may be implemented through hardware, but in many cases, the former is more preferable. Can be. Based on this understanding, the technical solutions of the present invention may be implemented in the form of software products in essential or contribution to the prior art, and the computer software products may comprise one storage medium (eg, ROM / RAM). , Magnetic disks, optical disks), which may include a plurality of instructions in one terminal device (which may be a mobile phone, a computer, a server, an air conditioner or a network device, etc.) described in each embodiment of the present invention. Performing.

As described above, the above embodiments are merely preferred embodiments according to the present invention, and the embodiments are not intended to limit the patent scope of the present invention. All equivalent structures or equivalent process transformations made by using the contents of the specification and drawings of the present invention, or directly or indirectly used in other related technical fields, are all understood to be included in the patent protection scope of the present invention for the same reason. Should be.

<Industrial practicality>

The present invention is applied to the field of communication technology, by the end node of the link to determine whether the signal quality through whether there is a signal degradation situation, such as disconnection, error frame on the link, and if the signal degradation situation occurs, the corresponding protection Switching operations can be performed to effectively increase ring network link performance.

Claims (16)

As a protection switching method for a ring network,
Detecting whether signal degradation has occurred in the link by an end node of the link, respectively; And
And performing a corresponding protective switching operation by a corresponding node when signal degradation occurs in the link. The method of claim 1,
Detecting whether or not signal degradation has occurred in the link by the end node of the link,
Receiving, by the end node of the link, a ring network link state monitoring message from the link oam, respectively, wherein the ring network link state monitoring message carries frame event parameters; And
And said terminating node determining, according to said frame event parameter, whether signal degradation has occurred in said link. The method of claim 2,
Before each detecting whether a signal degradation has occurred in the link by an end node of the link, the method further comprises:
Add a processing mechanism for signal degradation in the ring network protection state machine upon signal failure and ensure that the ring network protection state machine and ring network protection protocol message are compatible with the processing for signal degradation. Modifying the request / status bit value of the message. The method of claim 3,
Adding a handling mechanism for signal degradation in the ring network protection state machine upon signal failure and modifying the request / status bit value of the message of the ring network protection protocol upon signal failure,
Adding a local signal degradation (local SD) item, a local clear SD item, and a ring network auto-protection switching (R-APS-SD) item according to the signal degradation to the ring network protection request / status priority list. Including steps
In this case, the R-APS-SD item indicates that when the current end node is in the local SD state, the current end node informs an adjacent node that the current link is in a signal degradation state through the ring network protection protocol message after modification. Wherein the corresponding request / status bit value in the ring network protection protocol message indicates a signal degradation state. The method of claim 2,
The frame event parameter is
And at least one of an error symbol event parameter, an error frame event parameter, an error frame cycle event parameter, and an error frame second aggregate event parameter. The method of claim 2,
According to the frame event parameter, determining whether signal degradation has occurred in a ring network,
And determining that a signal degradation has occurred in the ring network when the cumulative number of occurrences of the frame event within a predetermined time exceeds a predetermined event threshold value. The method of claim 2,
Prior to receiving a ring network link status monitoring message from the link oam,
Establishing at least one ring network protection instance on the ring network; And
Receiving a registration message of each ring network protection instance, wherein the registration message carries a corresponding ring network protection instance indication. The method of claim 7, wherein
When signal degradation occurs in the ring network, the operation of performing a corresponding protection switching by the corresponding node,
When a signal degradation occurs in the ring network, sending a signal degradation indication to a corresponding ring network protection instance; And
And performing a corresponding protection switching operation in accordance with different ring network protection instances. The method according to any one of claims 2 to 8,
If a signal degradation occurs in the ring network, after performing the corresponding protection switching operation by the corresponding ring network node, the method further includes:
Continuing to receive a ring network link state monitoring message from a link oam, wherein the ring network link state monitoring message carries frame event parameters;
Determining, by the link end node, a ring network signal quality indicator according to the frame event parameter; And
If the ring network signal quality indicator is higher than a predetermined restoration threshold, restoring the ring network that has performed the protection switching operation to the initial ring network. The method of claim 1,
Detecting whether a signal degradation has occurred in the link by the end node of the link,
Determining whether signal degradation has occurred in the link by detecting attenuation of a laser signal. Protective switching device for a ring network,
A detector configured to respectively detect whether signal degradation has occurred in the link by an end node of the link; And
And a protection switching unit configured to perform a corresponding protection switching operation by a corresponding node when signal degradation occurs in the link. The method of claim 11,
The detection unit,
A receiving module, configured to respectively receive a ring network link state monitoring message from the link oam by an end node of the link, wherein the ring network link state monitoring message carries frame event parameters; And
And a determination module configured to determine, by the end node, whether signal degradation has occurred in the link according to the frame event parameter. The method of claim 12,
The ring network protection state upon signal failure such that a ring network protection state machine and a ring network protection protocol message are compatible with processing for signal degradation before each detecting whether a link degradation has occurred on the link by an end node of the link. And a modification configured to add a processing mechanism for signal degradation in the machine and to modify the request / status bit value of the ring network protection protocol message according to the signal failure. The method of claim 13,
Specifically, the correction unit
The local signal degradation (local SD) item, the local clear signal degradation (local clear SD) item, and the ring network auto-protection switching (R-APS-SD) item according to the signal degradation are added to the ring network protection request / status priority list. Configured to;
In this case, the R-APS-SD item indicates that when the current end node is in the local SD state, the current end node informs an adjacent node that the current link is in a signal degradation state through the ring network protection protocol message after modification. Wherein the corresponding request / status bit value in the ring network protection protocol message indicates a signal degradation state. The method of claim 12,
A setting unit configured to establish at least one ring network protection instance on the ring network before receiving a ring network link state monitoring message from a link oam; And
And a registration unit configured to receive a registration message of each ring network protection instance set by the setting unit, wherein the registration message conveys a corresponding ring network protection instance indication. A computer readable storage medium storing computer executable instructions, when the computer executable instructions are executed, implementing the protection switching method for the ring network described in any one of claims 1 to 10.

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