WO2008031347A1

WO2008031347A1 - Method and apparatus for realizing protection switching in the ring ethernet

Info

Publication number: WO2008031347A1
Application number: PCT/CN2007/070512
Authority: WO
Inventors: Suping Zhai; Yan Wang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-09-07
Filing date: 2007-08-17
Publication date: 2008-03-20
Also published as: CN101141364A

Abstract

A method for realizing protection switching in the ring Ethernet is provided, including: when the failure of the ring Ethernet have been detected in the ring Ethernet, initiating the delay timer which has been set predetermined, when the delay timer expired and the failure of the ring Ethernet have been detected for the second time, then switching the normal state to the failure state of the ring Ethernet. When the failure of the ring Ethernet have been eliminated, initiating the restoration waiting timer. When the restoration waiting timer expired, then performing the restoration of the normal state. An apparatus for realizing protection switching in the ring Ethernet is also provided.

Description

Method and device for implementing protection switching in ring Ethernet

Technical field

The present invention relates to Ethernet technology, and more particularly to a method and apparatus for implementing protection switching in a ring Ethernet. Background of the invention

Supporting multipoint connections is a unique feature of Ethernet. Multipoint connections can effectively support a wide range of communication services. In addition, in order to provide reliable communication in multipoint connections, a ring with protection switching mechanism can be used. Ethernet structure.

FIG. 1 is a schematic diagram of a conventional ring Ethernet structure. For convenience of description, the ring Ethernet structure is simply referred to as a ring network. As shown in Figure 1, as the only primary node in the ring network, S1 will block its secondary port for user data packets when the ring network is in normal communication to avoid broadcast storms caused by data loops. Generally, other non-primary nodes in the ring network other than the primary node S1 are referred to as transit nodes.

When a fault occurs in the ring network, S1 immediately triggers the corresponding protection switching operation. As shown in Figure 2, Figure 2 shows the schematic diagram of the existing ring Ethernet protection switching. In Figure 2, when a fault occurs in the ring network, S1 immediately enters the ring fault state, and opens its own secondary port for the user data message to allow the user data to pass; and, in S1 and the ring network The other nodes respectively refresh their forwarding tables to re-top the learning; in addition, S1 continuously sends polling messages in the ring network by its primary port. Once the ring network fault is removed, S1 can pass its secondary port. Receive the polling message sent by itself. In this case, S1 is restored to the normal state by the ring fault state, and its secondary port is blocked for user data packets to prohibit user data packets from passing.

In fact, the ring networks shown in Figure 1 and Figure 2 are hierarchical network structures, and each layer in the ring network. The network structure has a corresponding protection switching capability. When the underlying network structure in the ring network fails and fails to be repaired in time, it will affect the normal operation of the upper layer and cause the upper layer protection switching operation. The protection switching operation shown in Figure 2 is a protection switching operation at the data link layer.

Obviously, since the data link layer protection switching operation is performed immediately when a ring network failure occurs in the ring network, even if the lower layer network relative to the data link layer can eliminate the fault by its own protection switching operation, the lower layer The network structure also cannot obtain sufficient time to perform the corresponding protection switching operation before the protection switching operation at the data link layer. This will likely result in protection switching operations for both the underlying network fabric and the data link layer.

At this time, the protection switching operation performed by the data link layer is unnecessary.

In addition, since the fault state to the normal working state is resumed immediately after the ring network fault disappears in the ring network, if the link is unstable or intermittent defects occur, the data link layer performs frequent protection switching operations. .

The data link layer is used as an example. In fact, the network structure of each layer in the ring network has the problem of performing unnecessary or frequent protection switching operations, and unnecessary or frequent protection switching operations are performed. A lot of waste of network resources and a significant reduction in network performance. Summary of the invention

Embodiments of the present invention provide a method for implementing protection switching in a ring Ethernet to effectively avoid unnecessary protection switching operations.

Embodiments of the present invention provide a device for implementing protection switching in a ring Ethernet to effectively avoid unnecessary protection switching operations.

The technical solution of the embodiment of the present invention is implemented as follows:

A method for implementing protection switching in a ring Ethernet, the method comprising:

When a ring network fault is detected in the ring Ethernet, a preset delay timer is started; when the delay timer expires and the ring network fault is detected again, the normal work is performed. A protection switching operation in which the state switches to a ring fault state.

When the ring network fault is eliminated, a preset recovery wait timer is started; after the recovery wait timer expires, an operation for restoring to a normal working state is performed.

A device for implementing protection switching in a ring Ethernet, the device comprising: a ring network fault determination unit, a delay timer, and a protection switching unit;

The ring network fault determining unit is configured to control the delay timer to start when a ring network fault is detected in a normal working state, and perform loop network fault detection again when receiving the notification of the delay timer timeout. When the ring network fault is detected, the protection switching unit is controlled to perform a protection switching operation from a normal working state to a ring fault state;

The delay timer is configured to start according to the control of the ring network fault determining unit, and notify the ring network fault determining unit when timeout occurs;

The protection switching unit is configured to perform a protection switching operation of switching from a normal working state to a ring fault state according to the control of the ring network fault determining unit.

A device for implementing protection switching in a ring-shaped Ethernet, the device comprising: a recovery waiting timer, a ring network failure determining unit, and a protection switching unit;

The ring network failure determining unit is configured to control the recovery waiting timer to start when detecting that the ring network fault has been eliminated in the ring fault state, and continue to detect the link fault and control the recovery when the link fault is detected. Waiting for the timer to restart;

The recovery waiting timer is configured to start according to the control of the ring network failure determining unit, and notify the protection switching unit when timeout occurs;

The protection switching unit is configured to perform an operation for restoring to a normal working state according to the notification of the recovery waiting timer.

It can be seen that, by using the method and apparatus according to the embodiment of the present invention, when a ring network fault is detected in the ring Ethernet, a preset delay timer is started, and the timer is expired and checked again. When the ring network fault is detected, the protection switching operation is performed from the normal working state to the ring fault state. In this way, by setting the delay timer, the lower layer network obtains the time for performing the protection switching operation, so that the upper layer network does not perform unnecessary protection switching operations due to the fault that the lower layer network itself can solve.

When the ring network fault is eliminated, the preset recovery wait timer is started, and after the recovery wait timer expires, the operation for restoring to the normal working state is performed. In this way, by setting the recovery wait timer, it is ensured that the protection switching operation in the ring network is not frequently performed due to link instability or intermittent defects in the link, thereby avoiding unnecessary protection switching operations. BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent to those skilled in the <

1 is a schematic diagram of a conventional ring Ethernet structure;

2 is a schematic diagram of a conventional ring Ethernet protection switching;

3 is a flow chart of a preferred embodiment of the method of the present invention;

4 is a flow chart of another preferred embodiment of the method of the present invention;

FIG. 5 is a schematic structural diagram of a device according to an embodiment of the present invention; FIG.

Figure 6 is a schematic view showing the structure of another embodiment of the device of the present invention;

Figure 7 is a schematic view showing the structure of a device according to a preferred embodiment of the present invention. Mode for carrying out the invention

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

In an embodiment of the present invention, when a ring network fault is detected in the ring Ethernet, a preset delay timer is started, the delay timer expires, and the ring network fault is detected again. When performing the protection switching operation from the normal working state to the ring failure state; when the ring network failure is eliminated, the preset recovery waiting timer is started; after the recovery waiting timer expires, the execution is resumed to the normal working state. operating.

3 is a flow chart of a preferred embodiment of the method of the present invention. As shown in Figure 3, the following steps are included:

Step 310: When in a normal working state, the master node applies the prior art to detect a ring network fault in the ring network; when detecting the ring network fault, the process proceeds to step 320, and when no ring network fault is detected, the process returns to step 310.

The ring network fault is a link fault and/or a node fault; specifically, the master node can detect the ring network fault through a link state alarm mechanism or a polling mechanism. In the link state alarm mechanism, the transit node in the ring network can detect the ring network fault and send an alarm message to the master node by using the prior art; when receiving the alarm message from the transport node, the master node determines that the ring is detected. Network failure.

In the polling mechanism, the master node continuously sends polling messages in its ring network by its primary port. When the ring network works normally, the master node can receive the rounds sent by its own master port through its own secondary port. When the link is faulty, the master node cannot receive the polling message when the set failure period timer expires. In this case, the master node determines that the ring network fault is detected.

Step 320: The master node starts a preset delay timer.

Step 330: The master node determines whether the delay timer expires. If it times out, it proceeds to step 340; otherwise, returns to step 330.

Step 340: The master node detects a ring network fault in the ring network and determines whether a ring network fault is detected. If the ring network fault is detected, the process proceeds to step 350, and when no ring network fault is detected, the process returns to step 310.

Step 350: The primary node performs protection from the normal working state to the ring fault state. Change operation.

Specifically, the protection switching operation in this step includes: the primary node refreshes its own forwarding table, and opens its own secondary port for the user data packet to allow the user data packet to pass; and simultaneously sends a refresh to the transmission node in the ring network. The control message is advertised to notify the transmitting node to refresh the forwarding table. Further, the master node usually also continuously sends polling messages in the ring network by its primary port.

After this, the master node enters the ring failure state. The operation time setting required for the lower layer protection switching is to ensure the protection of the lower layer network structure as much as possible. The delay timer expires after the switching operation result. In this way, if the protection switching operation of the lower layer network structure is successfully completed, and the ring network failure is not detected again, there is no need to perform the protection switching operation of the current layer network structure; if the protection switching operation of the lower layer network structure fails to be successfully completed, Or the ring network fault is detected currently, and the protection switching operation of the current layer network structure is required.

It can be seen that, by setting the delay timer, the lower layer network structure obtains the time for performing the protection switching operation, so that the upper layer network structure does not perform unnecessary protection switching operations due to the fault that the lower layer network structure can solve, thereby making the current ring Unnecessary protection switching operations performed in the network are effectively avoided.

In the subsequent communication process, if the ring network failure in the ring network has been eliminated, the nodes in the ring network can perform the operations shown in FIG. In fact, the flow in Figure 4 is not necessarily related to the flow in Figure 3. In practical applications, the flow in Figure 3 can be performed separately, or the flow in Figure 4 can be performed separately.

4 is a flow chart of another preferred embodiment of the method of the present invention. As shown in FIG. 4, the following steps are included:

Step 410: The master node applies the existing technology to detect whether the ring network fault in the ring network has been eliminated. When it is determined that the ring network fault has been eliminated, the process proceeds to step 420, and when it is determined that the ring network fault has not been eliminated, the process returns to step 410.

Specifically, the master node may detect the ring network fault by using a link state alarm mechanism or a polling mechanism, and determine that the ring network fault has not been eliminated when the ring network fault is detected; and determine that the ring network fault has been detected when the ring network fault is not detected. eliminate.

Step 420: The master node starts a preset recovery wait timer.

Step 430: The primary node applies the prior art to detect the ring network fault in the ring network; when no ring network fault is detected, the process proceeds to step 440, and when the ring network fault is detected, the process returns to step 420.

Step 440: The master node determines whether the recovery wait timer expires. If it times out, it proceeds to step 450; otherwise, returns to step 430.

Step 450: The master node performs an operation for restoring to a normal working state.

Specifically, the operations performed by the master node include: refreshing the forwarding table of the user and re-blocking the secondary port of the user data packet to prohibit the user data packet from passing; sending a refresh notification control message to the transit node in the ring network, The forwarding node is notified to refresh the forwarding table; in addition, the primary node usually also continuously sends polling messages in the ring network by its primary port.

After this, the master node enters the normal working state.

The timing of the recovery wait timer may be set according to the actual application scenario, such as: according to the length of time required for link recovery to be stable and/or the possible duration of the link intermittent defect, to ensure that the link is stable or in the link. When the intermittent defect has not existed, the recovery wait timer expires.

It can be seen that by setting the recovery waiting timer, it can be ensured that the protection switching operation in the ring network is not frequently performed due to link instability or intermittent defects in the link, thereby avoiding unnecessary protection currently performed in the ring network. Switching operation.

Based on the foregoing method, in the embodiment of the present invention, two devices for implementing protection switching in a ring Ethernet are provided: FIG. 5 is a schematic structural diagram of an apparatus according to an embodiment of the present invention. As shown in FIG. 5, the device includes: a ring network failure determining unit 501, a delay timer 502, and a protection switching unit 503. The ring network fault determining unit 501 is configured to detect a ring network fault when the normal working state is detected. The delay timer 502 is started; and when the notification of the delay timer 502 is received, the ring network fault detection is performed again, and when the ring network fault is detected, the protection protection switching unit 503 performs the protection switching from the normal working state to the ring fault state. operating;

The delay timer 502 is configured to be started according to the control of the ring fault determining unit 501, and notify the ring fault determining unit 501 when timeout occurs;

The protection switching unit 503 is configured to perform a protection switching operation from the normal working state to the ring failure state according to the control of the ring network failure determining unit 501.

Figure 6 is a schematic view showing the structure of another embodiment of the apparatus of the present invention. As shown in FIG. 6, the device includes: a ring network failure decision unit 601, a recovery wait timer 602, and a protection switching unit 603;

The ring network fault determining unit 601 is configured to start the control recovery wait timer 602 when the ring network fault is detected in the ring fault state, and continue to detect the link fault and control the recovery wait timing when the link fault is detected. 602 restarts;

The recovery wait timer 602 is configured to start according to the control of the ring failure decision unit 601, and notify the protection switching unit 603 when the timeout occurs;

The protection switching unit 603 is configured to perform an operation for restoring to a normal working state according to the notification of the recovery waiting timer 602.

In practical applications, the functions shown in Figures 5 and 6 can be centralized in the same device, such as the master nodes mentioned in the processes of Figures 3 and 4, which are described below by way of a preferred embodiment:

Figure 7 is a schematic view showing the structure of a device according to a preferred embodiment of the present invention. As shown in FIG. 7, the ring network failure determining unit 710, the timing unit 720, and the protection switching unit 730 are respectively two or two. Connected, a delay timer 721 and a resume wait timer 722 are provided in the timing unit 720. Specifically, the ring network fault determining unit 710 is connected to the delay timer 721 and the protection switching unit 730, respectively, and the recovery waiting timer 722 is connected to the ring network fault determining unit 710 and the protection switching unit 730, respectively.

In a practical application, when a ring network fault is detected in a normal working state, the ring network fault determining unit 710 starts the delay timer 721 by using a transmission level signal or the like; the delay timer 721 sends a level signal when the timeout expires. The ring fault determining unit 710 is configured to perform the ring network fault detection again, and notify the protection switching unit 730 by sending a signal or the like when the ring network fault is detected, and the protection switching unit 730 performs normal operation. The protection switching operation of the state switching to the ring fault state.

Of course, if the ring network failure is not detected when the delay timer 721 times out, the ring network failure decision unit 710 may continue to detect the ring network fault later, and restart the delay by sending a level signal or the like when detecting the ring network fault. Timer 721.

When it is detected that the ring network failure has been eliminated in the ring failure state, the ring network failure decision unit 710 starts the recovery wait timer 722 in a manner of transmitting a level signal or the like, and performs ring network failure detection when the recovery wait timer 722 has not timed out. If the ring network failure is detected, the recovery wait timer 722 is restarted; otherwise, it returns to the state where the ring network failure detection is performed when the recovery wait timer 722 has not timed out.

The recovery wait timer 722 notifies the protection switching unit 730 by a transmission signal or the like at the time of timeout, and the protection switching unit 730 performs an operation for returning to the normal operation state.

It can be seen from the above that the method and apparatus provided by the embodiments of the present invention can effectively avoid unnecessary protection switching operations, thereby saving network resources and improving network performance.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements, etc., made within the spirit and principles of the present invention are It should be included in the scope of protection of the present invention.

Claims

Claim

A method for implementing protection switching in a ring Ethernet, characterized in that the method comprises:

When a ring network fault is detected in the ring Ethernet, a preset delay timer is started; when the delay timer expires and the ring network fault is detected again, protection from the normal working state to the ring fault state is performed. Switching operation.

The method according to claim 1, wherein the timing duration of the preset delay timer is an operation duration required for protection switching according to a current layer network structure requirement for protection switching speed and a lower layer network structure. Set.

3. The method according to claim 1, wherein the method further comprises: further detecting a ring network fault when the delay timer expires but not detecting a ring network fault, and detecting a ring network fault Restart the delay timer.

The method according to claim 1, wherein the protection switching operation comprises:

The primary node in the ring Ethernet refreshes its own forwarding table and opens its own secondary port for the user data packet, and sends a refresh notification control message to the transit node in the ring network.

The method according to claim 1, wherein the method further comprises: starting a recovery wait timer set in advance when the ring network fault is eliminated; performing recovery for recovery after the recovery wait timer expires Operation to normal working condition.

6. The method according to claim 5, wherein the method further comprises: restarting the recovery wait timer after detecting the ring network failure after the recovery wait timer is started.

The method according to claim 5, wherein the timing of the preset recovery wait timer is required to restore stability according to the link in the ring Ethernet network. Duration and/or duration of intermittent defects in the link are set.

The method according to claim 5, wherein the performing the operation for restoring to the normal working state comprises:

The master node refreshes its own forwarding table and re-blocks its own secondary port for user data packets, and sends a refresh notification control message to the transit node in the ring network.

The method according to any one of claims 1 to 8, wherein the method for detecting a ring network fault comprises:

The master node detects a ring network fault through a link state alarm mechanism or a polling mechanism.

The method according to claim 9, wherein the method for detecting a ring network fault by using a link state alarm mechanism comprises:

The master node determines that a ring network fault is detected when receiving an alarm message from the transport node.

The method according to claim 9, wherein the method for detecting a ring network fault by using a polling mechanism comprises:

In the case that the preset failure period timer expires, if the master node still does not receive the polling message that it has sent, the master node determines that the ring network fault is detected.

12. A method for implementing protection switching in a ring Ethernet, characterized in that the method comprises:

The method according to claim 12, wherein the method further comprises: restarting the recovery wait timer after detecting the ring network failure after the recovery wait timer is started.

The method according to claim 12, wherein the timing of the preset recovery wait timer is based on the link recovery stability in the ring Ethernet network. The length of time and/or the duration of the intermittent defect of the link is set.

The method according to claim 12, wherein the performing the operation for restoring to a normal working state comprises:

A device for implementing protection switching in a ring-shaped Ethernet, the device comprising: a ring network failure determining unit, a delay timer, and a protection switching unit; wherein, the ring network failure determining unit is configured to: Controlling the delay timer to start when a ring network fault is detected in a normal working state, and performing loop network fault detection again when receiving the notification of the delay timer timeout, and controlling the protection when a ring network fault is detected The switching unit performs a protection switching operation of switching from a normal working state to a ring fault state;

The device according to claim 16, wherein the device further includes a recovery waiting timer, wherein the recovery waiting timer is respectively connected to the ring network failure determining unit and the protection switching unit;

The ring network failure determining unit is further configured to control the recovery waiting timer to start when detecting that the ring network fault has been eliminated in the ring fault state, and continue to detect the link fault and control the link when the link fault is detected. Resume waiting for the timer to restart;

The protection switching unit is further configured to perform an operation for restoring to a normal working state according to the notification of the recovery waiting timer.

18. A device for implementing protection switching in a ring-shaped Ethernet, the device comprising: a recovery waiting timer, a ring network failure determining unit, and a protection switching unit;