CN104796329A - Automatic link switching method and automatic link switching device - Google Patents

Abstract

The present invention relates to the field of communication technology, in particular to a method and device for automatic link switching. In the prior art, when the port of the switching device connected to the transmission device has an electrical signal but some links fail, the switching device cannot detect the main link. If the link fails, automatic link switching cannot be realized, resulting in prolonged failure time of the long-distance transmission system and poor system stability. The present invention detects that the main transmission port does not receive the detection data frame in consecutive M cycles, then determines that the main link has a failure, closes the main link, and enables the standby link to work; avoids the failure of the switching equipment in the prior art Automatically identify the situation that the transmission equipment has electrical signals but the link is abnormal, which shortens the failure time of the long-distance transmission system and improves the reliability of the long-distance transmission system; There is a delay in receiving and detecting data frames on a port, and the probability of misjudging a link failure.

Description

A method and device for automatic link switching

technical field

The invention relates to the field of communication technology, in particular to a method and device for automatic link switching.

Background technique

With the continuous increase in the number of mobile users and the continuous update of user needs, the construction scale of the communication system is getting larger and larger, and each component in the system cannot be placed in the same physical location in the computer room. However, due to business requirements, the IP address of the entire system needs to be in the same network segment, so remote devices are usually connected to the system through long-distance transmission lines. In the process of long-distance transmission, in order to ensure the reliability of the transmission system, the "dual uplink" technology is usually used, that is, the main and standby two network cables are set on the switching device to connect to the peer device, and the switching device is connected to the peer device through the main network cable The corresponding link is called the active link, and the link that the switching device is connected to the peer device through the backup network cable is called the backup link. When the active link corresponding to the switching device fails, it switches to the standby link for data transmission.

The following is a specific example of the long-distance transmission system, which includes a first switching device, a first data server, a transmission device, a second switching device and a second data server; wherein the first switching device and the second switching device are respectively Contains two device ports and two transmission ports; each device port corresponds to a transmission port, that is, the active link in the switching device corresponds to the active device port and the active transmission port, and the standby link corresponds to the standby device port and The spare transmission port; the device port in the switching device is used for connecting with the data server, and the transmission port is used for connecting with the transmission device. When the first switching device is connected to the second switching device through the main link, the first switching device is connected to the first data server through the main device interface; the first switching device is connected to the transmission device through the main transmission port, and the second A part of the active link connecting the switching device to the transmission device through the active transmission port is designated as the active link segment 1; the second switching device is connected to the second data server through the main device interface; the second switching device is connected to the second data server through the active transmission The port is connected to the transmission device, and the part of the active link that the second switching device is connected to the transmission device through the active transmission port is designated as the active link segment 2.

The data transmission system performs data transmission through the main link as follows: the first data server sends the received service data frame to the first switching device; the first switching device receives the service sent by the first data server through the main device port data frame, the service data frame is forwarded from the main device port to the main transmission port; the main transmission port of the first switching device sends the service data frame to the transmission device through the main link segment 1, and the transmission device passes the main use Link segment 2 sends the service data frame to the second switching device; the second switching device receives the service data frame sent by the transmission device through the main transmission port, and forwards the service data frame from the main transmission port to the main device port ; The second switching device sends the service data frame to the second data server through the port of the active device. During the above data transmission process, when there is no abnormality in the active link segment 1 between the first switching device and the transmission device, the first switching device can detect the electrical signal of the main transmission port of the first switching device; The first switching device determines whether the active link fails according to whether there is an electrical signal at the active transmission port of the first switching device. When the first switching device detects the electrical signal of the active transmission port, it determines the active link Communication is normal. However, when the active link segment 2 between the second switching device and the transmission device fails, or the second switching device fails, but the active link segment 1 between the first switching device and the transmission device is not abnormal , the first switching device cannot know that the active link is abnormal, still determines that the active link is normal, and continues to send service data frames to the second transmission device through the active link. Only after receiving complaints from users, the operator determines that the active link is faulty, and manually enters the switching command to switch the active and standby links, so that the first switching device and the second switching device can return to normal through the standby link business.

Therefore, in the prior art, when there is an electrical signal at the transmission port of the switching device, but part of the active link fails, or the peer switching device fails, the switching device cannot detect that the active link is faulty, and cannot realize the failure of the link. Automatic switching leads to prolonged failure time of the long-distance transmission system and poor system stability.

Contents of the invention

Embodiments of the present invention provide a method and device for automatic link switching to solve the problem that in the prior art, when the transmission port of the switching device has electrical signals, but some active links fail, or the peer switching device fails, the switching device cannot Even if a failure of the active link is detected, the link cannot be switched automatically, resulting in prolonged failure time of the long-distance transmission system and poor system stability.

An embodiment of the present invention provides a method for automatic link switching, the method comprising:

After the first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device for M consecutive periods, it determines that the active link is faulty; wherein, the first switching device and the second switching device periodically send The other party sends the detection data frame;

The first switching device closes the active link and enables the standby link to work;

Wherein, M is a positive integer; the detection data frame is a specific data frame different from service data frames agreed in advance by the first switching device and the second switching device.

In the above-described embodiment, the first switching device detects that the active transmission port does not receive the detection data frame for M consecutive cycles, and then determines that the active link fails, and closes the active link and activates the standby link; In the existing technology, the switching equipment cannot automatically recognize that the transmission equipment has an electrical signal but the link is abnormal, which shortens the time for the failure of the long-distance transmission system; at the same time, it is determined that the main transmission port has not received the detection data frame through multiple cycles. Failure of the main link reduces the probability of misjudging the failure of the main link due to the poor network or network delay caused by the time delay of the main transmission port receiving the detection data frame, and improves the long-distance transmission system. reliability.

In the embodiment of the present invention, each switching device has a main/standby device port corresponding to the main/standby transmission port one by one, and the first switching device closes the main link and enables the standby link to work, specifically including:

triggering the active device port of the first switching device to stop receiving service data frames, and triggering to close the active device port of the first switching device;

The first switching device does not detect the electrical signal of the active device port for N consecutive periods, triggering the activation of the backup device port of the first switching device;

The first switching device triggers enabling the standby transmission port of the first switching device to transmit service data frames, and periodically sends detection data frames to the second switching device through the standby transmission port;

Wherein, N is a positive integer.

In the above embodiment, the power-on time of the backup device port and the shutdown time of the main transmission port are determined through the electrical signal of the main device port, and the automatic switching of the main and backup circuits is realized. The first switching device determines that the main link is abnormal, Then switch to the link corresponding to the second device port, and the second transmission port of the switching device periodically sends a detection data frame to the peer device corresponding to the switching device; the switching device realizes automatic link switching, and after switching the link according to Detecting the data frame determines the state of the link after switching, which shortens the failure time of the transmission system and improves the stability of the system.

In the embodiment of the present invention, after triggering and shutting down the active device port of the first switching device, it further includes:

After the first switching device triggers the active device port to be closed continuously for X periods, the first device triggers the active device port to be turned on;

The first switching device detects the electrical signal of the active device port for Y consecutive cycles, and triggers the active transmission port of the first switching device to send detection data frames to the second switching device for M consecutive cycles;

The first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device within the consecutive M periods, triggers to close the active port of the first switching device, and returns Trigger the active device port to shut down X cycle steps continuously;

The first switching device detects that the active transmission port has received the detection data frame sent by the second switching device within the consecutive M periods, then determines that the active link is restored, and triggers the active link of the first switching device. periodically sending a detection data frame to the second switching device by using a transmission port;

Wherein, X, Y, M are all positive integers, and X is not less than N.

In the above embodiment, after the port of the master device is closed for a set period of time, the first switching device notifies the port of the master device to enter the detection wait, powers on the port of the master device every set time length, and transmits data to the port of the master device through the master transmission port. The second switching device sends the detection data frame, and within the cycle of sending the detection data frame, detects whether the main transmission port receives the detection data frame sent by the second switching device, and if it is received, then determines that the main link returns to normal; After the active link returns to normal, the port of the active device is opened, and the detection data frame is periodically sent to the second switching device through the active transmission port. After the failure of the active link is restored, when the standby link fails, it can be switched to the active link at any time. The switching of the link by the switching device depends on the pre-agreed agreement between the first switching device and the second switching device; the closing or opening of the main transmission port does not depend on the electrical signal of the intermediate transmission device, so that the switching device can know the status of the link. Judgment is more accurate.

In the embodiment of the present invention, the method also includes:

When it is detected that the active link recovers from failure and the backup circuit fails, switch back to the active link to work.

The first switching device detects that the backup transmission port has not received the detection data frame sent by the second switching device for L consecutive cycles, and determines that the backup link is faulty;

The first switching device triggers the backup device port to stop receiving service data frames, and triggers to close the backup device port of the first switching device;

The first switching device does not detect the electrical signal of the standby device port for P consecutive periods, triggering the activation of the active device port of the first switching device;

The first switching device triggers enabling the primary transmission port of the first switching device to transmit service data frames, and periodically sends detection data frames to the second switching device through the standby transmission port;

Among them, L and P are both positive integers.

In the above embodiment, the power-on time of the main device port is determined through the electrical signal of the backup device port, and the automatic switching of the main and backup circuits is realized. When the first switching device determines that the backup link is abnormal, it switches to the main link. The main transmission port of the switching device periodically sends detection data frames; the switching device realizes automatic link switching, and after switching the link, determines the state of the switched link according to the detection data frame, shortening the failure time of the transmission system, Improved system stability.

In the embodiment of the present invention, after triggering to close the standby device port of the first switching device, it further includes:

The first switching device triggers the backup device port to be closed continuously for Z periods, and the first device triggers the backup device port to be turned on;

The first switching device detects the electrical signal of the backup device port for Q consecutive cycles, and triggers the backup transmission port of the first switching device to send detection data frames to the second switching device for L consecutive cycles;

The first switching device detects that the standby transmission port has not received the detection data frame sent by the second switching device in the continuous L cycles, triggers to close the standby device port of the first switching device, and returns to trigger the standby device port Close Z cycle steps consecutively;

The first switching device detects that the backup transmission port receives the detection data frame sent by the second switching device in the continuous L cycles, then determines that the backup link is restored, and triggers the backup transmission port of the first switching device periodically sending a detection data frame to the second switching device;

Among them, Z, L, Q are all positive integers, and Z is not less than P.

In the above-mentioned embodiment, after the standby device port is closed for a set period of time, the first switching device notifies the standby device port to enter the detection wait, powers up the standby device port once every set period of time, and sends a message to the second switching device through the standby transmission port. Detect the data frame, and in the cycle of sending the detection data frame, detect whether the standby transmission port has received the detection data frame sent by the second switching device, if received, then determine that the standby link is back to normal; after the standby link is back to normal , the standby device port is enabled, and the detection data frame is periodically sent to the second switching device through the standby transmission port. After the standby link is recovered from failure, when the active link fails, it can be switched to the standby link at any time. The switching of the link by the switching device depends on the pre-agreed agreement between the first switching device and the second switching device; the closing or opening of the standby transmission port does not depend on the electrical signal of the intermediate transmission device, so that the switching device can judge the link status more acurrate.

In the embodiment of the present invention, after the active device port of the first switching device is triggered to stop receiving the service data frame, before the standby transmission port of the first switching device is triggered to transmit the service data frame, the steps further include:

The first switching device detects that the active transmission port has received the service data frame sent by the second switching device side, forwards the service data frame from the active transmission port to the active device port, and the active device port sends and processes the service data frame .

In the above-mentioned embodiment, when the port of the main device is closed and the port of the backup device has not been activated, the service data frame sent by the second switching device is received, and it is still sent through the port of the main device; the loss of the service data frame is reduced, Improve the reliability of the system.

An embodiment of the present invention provides an automatic link switching device, which is applied to the automatic switching of the main/standby link established by two switching devices through the main/standby transmission port, and the device includes:

The detection unit is configured to detect that the primary transmission port of the first switching device has not received the detection data frame sent by the second switching device for M consecutive cycles, and determine that the primary link is faulty; wherein, the first switching device and The second switching device periodically sends the detection data frame to the other party; M is a positive integer; the detection data frame is a specific type that is different from the service data frame and is pre-agreed by the first switching device and the second switching device. Data Frame;

A switching unit, configured to close the active link and enable the standby link to work.

In the above-described embodiment, the first switching device detects that the active transmission port does not receive the detection data frame for M consecutive cycles, and then determines that the active link fails, and closes the active link and activates the standby link; In the existing technology, the switching equipment cannot automatically recognize that the transmission equipment has an electrical signal but the link is abnormal, which shortens the time for the failure of the long-distance transmission system; at the same time, it is determined that the main transmission port has not received the detection data frame through multiple cycles. Failure of the main link reduces the probability of misjudging the failure of the main link due to the poor network or network delay caused by the time delay of the main transmission port receiving the detection data frame, and improves the long-distance transmission system. reliability.

In the embodiment of the present invention, each switching device has a master/standby device port corresponding to the master/standby transmission port one by one, and the switching unit is specifically used for:

triggering the active device port of the first switching device to stop receiving service data frames, and triggering to close the active device port of the first switching device;

The detection unit is specifically configured to: not detect the electrical signal of the active device port of the first switching device for N consecutive periods; the switching unit is specifically configured to: trigger and activate the standby device port of the first switching device ; triggering the standby transmission port of the first switching device to transmit service data frames, and periodically sending detection data frames to the second switching device through the standby transmission port;

Wherein, N is a positive integer.

In the above embodiment, the power-on time of the backup device port and the shutdown time of the main transmission port are determined through the electrical signal of the main device port, and the automatic switching of the main and backup circuits is realized. The first switching device determines that the main link is abnormal, Then switch to the link corresponding to the second device port, and the second transmission port of the switching device periodically sends a detection data frame to the peer device corresponding to the switching device; the switching device realizes automatic link switching, and after switching the link according to Detecting the data frame determines the state of the link after switching, which shortens the failure time of the transmission system and improves the stability of the system.

The switching unit described in the embodiment of the present invention is also used for:

After triggering the active device port to be closed for X consecutive cycles, trigger to open the active device port;

The detection unit is further configured to detect the electrical signal of the main device port for Y consecutive cycles, and trigger the primary transmission port of the first switching device to send detection data frames to the second switching device for M consecutive cycles;

The detecting unit is further configured to detect that the primary transmission port has not received the detection data frame sent by the second switching device within the consecutive M periods; the switching unit is further configured to trigger the shutdown of the first The active device port of the switching device;

The detection unit is further configured to detect that the active transmission port receives a detection data frame sent by the second switching device within the consecutive M periods, then determine that the active link is restored; trigger the first switching device The primary transmission port periodically sends a detection data frame to the second switching device;

Wherein, X, Y, M are all positive integers, and X is not less than N.

In the above embodiment, after the port of the master device is closed for a set period of time, the first switching device notifies the port of the master device to enter the detection wait, powers on the port of the master device every set time length, and transmits data to the port of the master device through the master transmission port. The second switching device sends the detection data frame, and within the cycle of sending the detection data frame, detects whether the main transmission port receives the detection data frame sent by the second switching device, and if it is received, then determines that the main link returns to normal; After the active link returns to normal, the port of the active device is opened, and the detection data frame is periodically sent to the second switching device through the active transmission port. After the failure of the active link is restored, when the standby link fails, it can be switched to the active link at any time. The switching of the link by the switching device depends on the pre-agreed agreement between the first switching device and the second switching device; the closing or opening of the main transmission port does not depend on the electrical signal of the intermediate transmission device, so that the switching device can know the status of the link. Judgment is more accurate.

The detection unit described in the embodiment of the present invention is specifically used for:

Detecting that the standby transmission port has not received the detection data frame sent by the second switching device for L consecutive cycles, and determining that the standby link is faulty;

The switching unit is specifically configured to trigger the backup device port to stop receiving service data frames, and trigger to close the backup device port of the first switching device;

The detection unit is specifically configured to detect no electrical signal of the standby device port for P consecutive periods; the switching unit is specifically configured to trigger the activation of the primary device port of the first switching device; trigger the activation of the first switching device port; The main transmission port of the switching device transmits the service data frame, and notifies the detection unit to periodically send the detection data frame to the second switching device through the standby transmission port;

Among them, L and P are both positive integers.

In the above embodiment, the power-on time of the main device port is determined through the electrical signal of the backup device port, and the automatic switching of the main and backup circuits is realized. When the first switching device determines that the backup link is abnormal, it switches to the main link. The main transmission port of the switching device periodically sends detection data frames; the switching device realizes automatic link switching, and after switching the link, determines the state of the switched link according to the detection data frame, shortening the failure time of the transmission system, Improved system stability.

The switching unit described in the embodiment of the present invention is also used for:

Trigger the backup device port to close Z cycles continuously, and trigger the backup device port to open;

The detection unit is also used to detect the electrical signal of the backup device port for Q consecutive cycles, and trigger the backup transmission port of the first switching device to send detection data frames to the second switching device for L consecutive cycles;

The detection unit is specifically used to detect that the standby transmission port has not received the detection data frame sent by the second switching device in the continuous L cycles; the switching unit is used to trigger the shutdown of the standby transmission port of the first switching device. device port;

The detection unit is specifically configured to detect that the backup transmission port receives the detection data frame sent by the second switching device in the continuous L cycles, then determine that the backup link is restored, and trigger the backup of the first switching device. The transmission port periodically sends detection data frames to the second switching device;

Among them, Z, L, Q are all positive integers, and Z is not less than P.

In the above-mentioned embodiment, after the standby device port is closed for a set period of time, the first switching device notifies the standby device port to enter the detection wait, powers up the standby device port once every set period of time, and sends a message to the second switching device through the standby transmission port. Detect the data frame, and in the cycle of sending the detection data frame, detect whether the standby transmission port has received the detection data frame sent by the second switching device, if received, then determine that the standby link is back to normal; after the standby link is back to normal , the standby device port is enabled, and the detection data frame is periodically sent to the second switching device through the standby transmission port. After the standby link is recovered from failure, when the active link fails, it can be switched to the standby link at any time. The switching of the link by the switching device depends on the pre-agreed agreement between the first switching device and the second switching device; the closing or opening of the standby transmission port does not depend on the electrical signal of the intermediate transmission device, so that the switching device can judge the link status more acurrate.

The switching unit described in the embodiment of the present invention is also used for:

After the active port of the first switching device is triggered to stop receiving service data frames, before the standby transmission port of the first switching device is triggered to transmit service data frames, it is detected that the active transmission port of the first switching device receives the second switching device The service data frame sent by the side forwards the service data frame from the main transmission port to the main equipment port, and the main equipment port sends and processes the service data frame.

In the above-mentioned embodiment, when the port of the main device is closed and the port of the backup device has not been activated, the service data frame sent by the second switching device is received, and it is still sent through the port of the main device; the loss of the service data frame is reduced, Improve the reliability of the system.

In the embodiment of the present invention, after the first switching device detects that the primary transmission port has not received the detection data frame sent by the second switching device for M consecutive cycles, it determines that the primary link is faulty; the first switching device closes the primary link, Enable the standby link to work; the first switching device detects that the main transmission port does not receive the detection data frame by continuous M cycles, then it is determined that the main link fails, and the main link is closed, and the standby link is enabled; avoid It solves the situation that the switching equipment in the prior art cannot automatically recognize that the transmission equipment has an electrical signal but the link is abnormal, and shortens the time for the failure of the long-distance transmission system; at the same time, it detects that the main transmission port has not received the detection data frame through multiple cycles, It is determined that the main link is faulty, which reduces the probability of misjudgment that the main link is faulty due to poor network or network delay caused by the delay in receiving the detection data frame at the main transmission port, and improves the long-distance The reliability of the transmission system.

Description of drawings

FIG. 1 is a schematic flow diagram of a method for automatic link switching in an embodiment of the present invention;

FIG. 2 is a schematic flowchart of a specific method for automatic link switching in an embodiment of the present invention;

FIG. 3 is a schematic flowchart of another method for automatic link switching in an embodiment of the present invention;

Fig. 4 is a schematic diagram of an automatic link switching device in an embodiment of the present invention.

Detailed ways

Embodiments of the present invention provide a method and device for automatic link switching. The first switching device determines whether the active link fails according to the detection data frame periodically sent by the second switching device, and determines whether the active link fails and switches to Backup link; it avoids relying on the electrical signal of the transmission equipment to determine the current work of the link, improves the accuracy of judging the working status of the link, realizes the automatic switching of the link, shortens the time of failure of the long-distance transmission system, and improves the reliability of the link. Reliability of long-distance transmission systems.

The present invention will be further described below in conjunction with the accompanying drawings of the description.

As shown in Figure 1, it is a kind of link automatic switching method in the embodiment of the present invention, is applied to the automatic switching of the active/standby link that two switch devices establish through active/standby transmission port, and this method comprises:

Step 101: After the first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device for M consecutive periods, it determines that the active link is faulty; wherein, the first switching device and the second switching device cycle sending the detection data frame to the other party;

Step 102: the first switching device shuts down the active link, and enables the standby link to work;

Wherein, M is a positive integer; the detection data frame is a specific data frame different from the service data frame pre-agreed by the first switching device and the second switching device.

In step 101, the first switching device detects that the main transmission port has not received the detection data frame sent by the second switching device for M consecutive cycles, specifically including: the first switching device detects the detection data frame received by the main transmission port, when The first switching device detects that the main transmission port has not received the detection data frame within one cycle, and then enters the logic waiting state. When the first switching device enters the logic waiting state, it detects the main transmission port for M-1 consecutive cycles If the detection data frame is not received, it is determined that the active link fails, where M is a positive integer. If it is pre-set that the first switching device detects that the primary transmission port has not received the detection data frame for 5 consecutive cycles, it is determined that the primary link has failed; After detecting the data frame, it enters the logical waiting state. After the first switching device enters the logical waiting state, it detects that the active transmission port does not receive the detection data frame for 4 consecutive cycles, and then determines that the active link fails.

The first switching device detects that the main transmission port does not receive the detection data frame for M consecutive cycles, and then determines that the link corresponding to the main transmission port is faulty, avoiding that the switching device in the prior art cannot automatically identify that the transmission device has power The signal but the link is abnormal, which shortens the failure time of the long-distance transmission system and improves the reliability of the long-distance transmission system; at the same time, it is determined that the main transmission port has not received the detection data frame through multiple cycles The failure of the link reduces the probability of misjudging that the link corresponding to the main transmission port is faulty due to the delay in receiving the detection data frame due to poor network or network delay.

Each switching device has a primary/standby device port corresponding to a primary/standby transmission port one-to-one.

In step 102, the first switching device closes the active link and enables the standby link to work, specifically including: the first switching device determines that the active link fails, triggers the shutdown of the active device port corresponding to the active transmission port, and simultaneously A switching device performs power-on processing on the standby device port. After the first switching device triggers to close the port of the active device, the port of the active device no longer outputs electrical signals. If the first switching device does not detect the electrical signal of the port of the active device for N consecutive cycles, it triggers the opening of the first switching device. Standby device port; at the same time, the first switching device triggers to enable the standby transmission port of the first switching device to transmit service data frames, and periodically sends detection data frames to the second switching device through the standby transmission port; wherein, N is a positive integer.

After the first switching device triggers to close the active device port of the first switching device, it also includes: after the first switching device triggers the active device port to be closed continuously for X periods, the first device triggers to open the active device port; the first switch The device detects the electrical signal of the active device port for Y consecutive cycles, and triggers the active transmission port of the first switching device to send a detection data frame to the second switching device for M consecutive cycles; the first switching device detects that within M consecutive cycles If the main transmission port does not receive the detection data frame sent by the second switching device, it triggers the shutdown of the main device port of the first switching device, and returns to trigger the continuous shutdown of the main device port for X cycle steps; the first switching device detects that the continuous In M cycles, the active transmission port receives the detection data frame sent by the second switching device, then it is determined that the active link is restored, and the active transmission port of the first switching device is triggered to periodically send the detection data frame to the second switching device; wherein , X, Y, M are all positive integers, and X is not less than N.

If the first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device within 5 consecutive cycles, it determines that the active link is faulty and triggers the shutdown of the active port; If the electrical signal of the main device port is not detected within the period, the first switching device triggers the activation of the backup device port; the device connected to the first switching device detects that there is no electrical signal at the main device port, and then sends the service data frame through the backup device port To the first switching device, the first switching device forwards the service data frame from the backup device port to the backup transmission port, and sends the service data frame to the second switching device through the backup transmission port; the first switching device does not detect The electrical signal of the main transmission port triggers the opening of the main equipment port, and the first switching device detects the electrical signal of the main equipment port, then triggers the first main transmission port to send detection data frames to the second switching equipment for 5 consecutive cycles , if within these 5 cycles, the primary transmission port does not receive the detection data frame sent by the second switching device, then return to the step of closing the port of the primary device for consecutive cycles; if within these 5 cycles, the primary When the transmission port receives the detection data frame sent by the second switching device, it determines that the active link is back to normal, and triggers the active transmission port to periodically send the detection data frame to the second device; in order to switch back to the active link when the backup link fails. Use the link.

Preferably, the method further includes: switching back to the active link to work when it is detected that the active link fails and the backup circuit fails.

The first switching device detects that the backup transmission port has not received the detection data frame sent by the second switching device for L consecutive cycles, and determines that the backup link is faulty; the first switching device triggers the port of the backup device to stop receiving service data frames, and triggers the shutdown of the second switching device A backup device port of a switching device; the first switching device does not detect the electrical signal of the backup device port for P consecutive cycles, triggering the activation of the active device port of the first switching device; the first switching device triggers the activation of the primary device port of the first switching device Use the transmission port to transmit the service data frame, and periodically send the detection data frame to the second switching device through the standby transmission port; wherein, L and P are both positive integers.

After triggering to close the backup device port of the first switching device, it also includes: the first switching device triggers the backup device port to be closed continuously for Z cycles, and the first device triggers to open the backup device port; the first switching device detects the backup port for Q consecutive cycles The electrical signal of the device port triggers the standby transmission port of the first switching device to send detection data frames to the second switching device for L consecutive cycles; the first switching device detects that the standby transmission port has not received the second switching device for L consecutive cycles The detection data frame sent triggers the shutdown of the backup device port of the first switching device, and returns to the step of triggering the shutdown of the backup device port for Z consecutive cycles; the first switching device detects that the backup transmission port receives the second switching device in consecutive L cycles If the detection data frame is sent, it is determined that the backup link is restored, and the backup transmission port of the first switching device is triggered to periodically send a detection data frame to the second switching device; wherein, Z, L, and Q are all positive integers, and Z is not less than P .

If the first switching device detects that the standby transmission port has not received the detection data frame sent by the second switching device for 5 consecutive cycles, it determines that the backup link is faulty; the first switching device triggers the standby device port to stop receiving service data frames, and triggers Close the backup device port of the first switching device; the first switching device does not detect the electrical signal of the backup device port within one cycle, and the first switching device triggers the activation of the active device port; the device connected to the first switching device detects the backup device If there is no electrical signal at the port, the service data frame is sent to the first switching device through the port of the main device, and the first switching device forwards the service data frame from the port of the main device to the main transmission port, and transmits the service data through the main transmission port The frame is sent to the second switching device; the first switching device does not detect the electrical signal of the backup transmission port for two consecutive cycles, triggering the opening of the backup device port, and the first switching device detects the electrical signal of the backup device port, then triggers the first backup The transmission port sends the detection data frame to the second switching device for 5 consecutive cycles. If the standby transmission port does not receive the detection data frame sent by the second switching device within these 5 cycles, it returns to the standby device port and closes it for two consecutive cycles. The step; If within these 5 cycles, the standby transmission port receives the detection data frame sent by the second switching device, then it is determined that the standby link is back to normal, and the standby transmission port is triggered to periodically send the detection data frame to the second equipment; so that the master When the active link fails, switch back to the standby link.

In the embodiment of the present invention, when the service data frame is sent through the active link and the standby link does not fail, the standby link periodically sends a detection data frame to the second switching device through the standby transmission port to determine the current status of the standby link. No fault occurs; when the service data frame is sent through the standby link and the active link is not faulty, the active link periodically sends detection data frames to the second switching device through the active transmission port to determine the active link There is currently no failure; so that when a link in the first switching device fails, another link without failure can be used.

Preferably, when the device connected to the first switching device detects that there is no electrical signal at the port of the active device, it automatically stops sending service data frames to the port of the active device, and sends service data frames to the first switching device through the port of the standby device.

The first switching device receives the service data frame sent by the second switching device through the primary transmission port, and sends the received service data frame to the port of the primary device, and the first switching device sends the service data frame to the port of the primary device through the port of the primary device. A switching device is connected to the device. The first switching device detects that the port of the active device receives the service data frame sent by the connected device, and sends the service data frame to the active transmission port, and the first switching device sends the service data frame to the second through the active transmission port. Two switching devices.

After the first switching device triggers the active device port to stop receiving service data frames, before triggering the start of the standby transmission port of the first switching device to transmit service data frames, the first switching device detects that the active transmission port receives the second switch For the service data frame sent by the device side, the service data frame is forwarded from the active transmission port to the active device port, and the active device port sends and processes the service data frame.

Preferably, according to the IEEE802.3 protocol in the embodiment of the present invention, after being processed by the physical layer and the logical link layer, the data included in the data frame will be delivered to the high-level protocol specified in the type field. Although the Ethernet protocol does not explicitly specify the completion requirement, the minimum length of the data frame in the Ethernet frame should not be less than 46 bytes, so as to ensure that the maximum data frame length of the 802.3 protocol is 1518 bytes, and the minimum value is 64 bytes. Festival.

In order to reduce the amount of forwarding, the detection data frame length in the embodiment of the present invention is set to 46 bytes, plus fields such as the preamble, delimiter, type, check code of the detection data frame, just reach the minimum of the Ethernet data frame The length is 64 bytes. The detection data frame of 46 bytes in the present invention can adopt the following format: "1111000011110000..." or "0xF0F0F0F0F0F0F0F0F0...". The detection data frame exemplified in the above embodiment is a relatively common format of the detection data frame in the embodiment of the present invention, and detection data frames in other formats are also applicable to the present invention.

As shown in Figure 2, it is a specific method for link automatic switching in the embodiment of the present invention, the method includes:

Step 201: The primary transmission port of the first switching device periodically receives the detection data frame sent by the second switching device;

Step 202: The first switching device detects the detection data frame sent by the second switching device that has not been received by the active transmission port in the current cycle;

Step 203: The first switching device judges whether the active transmission port has received the detection data frame sent by the second transmission device in four consecutive cycles after the current cycle, and if so, returns to step 201, otherwise executes step 204;

Step 204: the first switching device triggers to shut down the active device port, and at the same time triggers to enable the standby device port of the first switching device;

Step 205: the first switching device does not detect the electrical signal of the port of the active device within the current cycle, triggering the shutdown of the active transmission port;

Step 206: The first switching device detects the electrical signal of the port of the backup device for two consecutive cycles, and triggers the first switching device to transmit the service data frame through the backup transmission port;

Step 207: The first switching device triggers the standby transmission port to periodically send a detection data frame to the second switching device; and ends this process.

In the above embodiment, step 205 and step 206 are not strictly in sequence, and step 205 may be executed first, and then step 206 may be executed, or step 205 and step 206 may be executed simultaneously. The period length exemplified in this embodiment is a preferred period length in the embodiment of the present invention, and other period lengths are also applicable to the embodiment of the present invention.

As shown in Figure 3, it is a detection method for link failure recovery in the embodiment of the present invention, the method includes:

Step 301: The first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device within 5 consecutive cycles, and triggers the shutdown of the active device port;

Step 302: The first switching device detects a signal that the port of the active device is closed for two consecutive cycles, and triggers the port of the active device to be turned on;

Step 303: The first switching device detects a signal that the port of the active device is turned on in the current cycle, and triggers the active transmission port to send detection data frames for 5 consecutive cycles;

Step 304: the first switching device detects whether the detection data frame sent by the second switching device is received within 5 cycles of the detection data frame sent by the main transmission port, if not received, return to step 301, otherwise execute step 305;

Step 305: The first switching device determines that the active link is back to normal, and periodically sends a detection data frame to the second switching device through the active transmission port, and ends the process.

In the embodiment of the present invention, the embodiments shown in Fig. 2 and Fig. 3 are both the process of switching the active link to the standby link. The process of switching the standby link to the active link in the present invention is similar, and will not be described here Further details; the period set in the embodiment is the preferred period length in the embodiment of the present invention, and other period lengths conforming to the concept of the present invention are also applicable to the present invention, and will not be listed here.

Based on the same inventive concept, an automatic link switching device is also provided in the embodiment of the present invention. Since the problem-solving principle of the device is similar to a link automatic switching method in the embodiment of the present invention, the implementation of the device can be found in the method The implementation of the implementation, the repetition will not repeat them.

As shown in Figure 4, it is a link automatic switching device in the embodiment of the present invention, which is applied to the automatic switching of the main/standby link established by two switching devices through the main/standby transmission port, the device includes a detection unit 401, Switching unit 402:

The detection unit 401 is configured to detect that the active transmission port of the first switching device has not received the detection data frame sent by the second switching device for M consecutive cycles, and determine that the active link is faulty; wherein, the first switching device and the second switching device The second switching device periodically sends a detection data frame to the other party; M is a positive integer; the detection data frame is a specific data frame different from the service data frame agreed in advance by the first switching device and the second switching device;

The switching unit 402 is configured to close the active link and enable the standby link to work.

The detection unit 401 is specifically used to detect the detection data frame received by the primary transmission port of the first switching device, and when it is detected that the primary transmission port of the first switching device does not receive the detection data frame within one cycle, enter the logic waiting state, after entering the logical waiting state, if it is detected that the active transmission port does not receive the detection data frame for M-1 consecutive cycles, it is determined that the active link is faulty, where M is a positive integer. If it is preset that the active transmission port of the first switching device does not receive the detection data frame for 5 consecutive cycles, it is determined that the active link has failed; After receiving the detection data frame, it enters the logical waiting state. After entering the logical waiting state, it is detected that the active transmission port does not receive the detection data frame for 4 consecutive cycles, and it is determined that the active link is faulty.

Using continuous M cycles to detect that the primary transmission port of the first switching device does not receive the detection data frame, it is determined that the link corresponding to the primary transmission port is faulty, which avoids the failure of the switching device in the prior art to automatically identify that the transmission device is faulty In case of electrical signal but link abnormality, the failure time of the long-distance transmission system is shortened, and the reliability of the long-distance transmission system is improved; at the same time, it is determined that the main The failure of the active link reduces the probability of misjudging that the link corresponding to the active transmission port is faulty due to the delay in receiving the detection data frame at the active transmission port due to poor network or network delay.

Each switching device has a primary/standby device port corresponding to a primary/standby transmission port one-to-one.

The switching unit 402 is specifically configured to: determine that the primary link of the first switching device fails, trigger shutdown of the primary device port corresponding to the primary transmission port, and simultaneously power on the backup device port of the first switching device. After triggering to close the active device port of the first switching device, the active device port no longer outputs electrical signals, and if no electrical signal is detected from the active device port of the first switching device for N consecutive cycles, the first switching device is triggered to be turned on. The backup device port of the device; at the same time, the first switching device triggers the activation of the backup transmission port of the first switching device to transmit service data frames, and periodically sends detection data frames to the second switching device through the backup transmission port; wherein, N is a positive integer.

The switching unit 402 is also used to trigger the opening of the port of the master device after triggering the port of the master device to be closed continuously for X cycles; the detection unit 401 detects the electrical signal of the port of the master device for Y consecutive cycles, and triggers the master port of the first switching device Use the transmission port to send the detection data frame to the second switching device for M consecutive cycles; the detection unit 401 detects that the primary transmission port has not received the detection data frame sent by the second switching device for M consecutive cycles, and the switching unit 402 triggers the shutdown of the second switching device. A main device port of the switching device, and return to trigger the step of closing the main device port continuously for X cycles; the detection unit 401 detects that the detection data frame sent by the second switching device is received by the main transmission port in M consecutive cycles, then Determine the recovery of the active link, and trigger the active transmission port of the first switching device to periodically send a detection data frame to the second switching device; where X, Y, and M are all positive integers, and X is not less than N.

If the detection unit 401 detects that the primary transmission port has not received the detection data frame sent by the second switching device within 5 consecutive cycles, then it is determined that the primary link is faulty, and the switching unit 402 triggers to close the port of the primary device; If the electrical signal of the active device port is not detected within one cycle, the switching unit 402 triggers the activation of the standby device port; the device connected to the first switching device detects that there is no electrical signal at the active device port, and then sends the service data frame through the standby device port To the first switching device, the first switching device forwards the service data frame from the backup device port to the backup transmission port, and sends the service data frame to the second switching device through the backup transmission port. The detection unit 401 does not detect the electrical signal of the main transmission port for two consecutive cycles, and the switching unit 402 triggers to open the main equipment port; the detection unit 401 detects the electrical signal of the main equipment port, then triggers the first main transmission port to continue Send detection data frames to the second switching device for 5 cycles, if within these 5 cycles, the detection unit 401 detects that the primary transmission port has not received the detection data frame sent by the second switching device, then return to the primary device port and continue to close The steps of consecutive cycles; if within these 5 cycles, the detection unit 401 detects that the primary transmission port receives the detection data frame sent by the second switching device, then it is determined that the primary link returns to normal, and triggers the primary transmission port to periodically send The second device sends a detection data frame so as to switch back to the active link when the standby link fails.

Preferably, the switching unit 402 is further configured to switch back to work on the active link after detecting that the active link fails and the standby circuit fails.

The detection unit 401 detects that the standby transmission port has not received the detection data frame sent by the second switching device for L consecutive periods, and determines that the standby link is faulty; the switching unit 402 triggers the standby device port to stop receiving service data frames, and triggers to close the first The backup device port of the switching device; the detection unit 401 does not detect the electrical signal of the backup device port for P consecutive cycles, and the switching unit 402 triggers the activation of the primary device port of the first switching device; triggers the activation of the primary transmission port of the first switching device The service data frame is transmitted, and the detection data frame is periodically sent to the second switching device through the standby transmission port; wherein, L and P are both positive integers.

Wherein the switching unit 402 is also used to: trigger the standby equipment port to be closed continuously for Z periods, and trigger to open the standby equipment port; the detection unit 401 detects the electrical signal of the standby equipment port for Q consecutive periods, and triggers the standby transmission port of the first switching equipment to continuously L cycles send the detection data frame to the second switching device; the detection unit 401 detects that the standby transmission port has not received the detection data frame sent by the second switching device in consecutive L cycles, and the switching unit 402 triggers off the backup of the first switching device device port, and return to trigger the backup device port to be closed continuously for Z cycles; the detection unit 401 detects that the backup transmission port receives the detection data frame sent by the second switching device in consecutive L cycles, then determines that the backup link is restored, and triggers the first The standby transmission port of the switching device periodically sends the detection data frame to the second switching device; wherein, Z, L, and Q are all positive integers, and Z is not less than P.

If the detection unit 401 detects that the standby transmission port has not received the detection data frame sent by the second switching device for 5 consecutive cycles, it is determined that the backup link is faulty; A backup device port of a switching device; the detection unit 401 does not detect the electrical signal of the backup device port within one cycle, and the switching unit 402 triggers to enable the main device port; the device connected to the first switching device detects that the backup device port has no electrical signal , the service data frame is sent to the first switching device through the port of the active device, the first switching device forwards the service data frame from the port of the active device to the active transmission port, and sends the service data frame to the first switching device through the active transmission port Two switching equipment; the detection unit 401 does not detect the electrical signal of the standby transmission port for two consecutive cycles, the switching unit 402 triggers to open the standby equipment port, and the detection unit 401 detects the electrical signal of the standby equipment port, then triggers the first standby transmission port to continue Send detection data frames to the second switching device for 5 cycles, if within these 5 cycles, the detection unit 401 detects that the standby transmission port has not received the detection data frame sent by the second switching device, then returns to the standby device port and closes two consecutive period; if within these 5 periods, the detection unit 401 detects that the standby transmission port receives the detection data frame sent by the second switching device, then it is determined that the standby link is back to normal, and the standby transmission port is triggered to periodically send the detection data frame to the second device ; In order to switch back to the standby link when the active link fails.

In the embodiment of the present invention, when the service data frame is sent through the active link and the standby link does not fail, the standby link periodically sends a detection data frame to the second switching device through the standby transmission port to determine the current status of the standby link. No fault occurs; when the service data frame is sent through the standby link and the active link is not faulty, the active link periodically sends detection data frames to the second switching device through the active transmission port to determine the active link There is currently no failure; so that when a link in the first switching device fails, another link without failure can be used.

Preferably, when the device connected to the first switching device detects that there is no electrical signal at the port of the active device, it automatically stops sending service data frames to the port of the active device, and sends service data frames to the first switching device through the port of the standby device.

The first switching device receives the service data frame sent by the second switching device through the primary transmission port, and sends the received service data frame to the port of the primary device, and the first switching device sends the service data frame to the port of the primary device through the port of the primary device. A switching device is connected to the device. The first switching device detects that the port of the active device receives the service data frame sent by the connected device, and sends the service data frame to the active transmission port, and the first switching device sends the service data frame to the second through the active transmission port. Two switching devices.

The switching unit is also used for: after triggering the port of the active device to stop receiving the service data frame, before triggering the standby transmission port of the first switching device to transmit the service data frame, detecting that the active transmission port has received the service sent by the second switching device The data frame forwards the service data frame from the main transmission port to the main equipment port, and sends and processes the service data frame through the main equipment port.

Preferably, according to the IEEE802.3 protocol in the embodiment of the present invention, after being processed by the physical layer and the logical link layer, the data included in the data frame will be delivered to the high-level protocol specified in the type field. Although the Ethernet protocol does not explicitly specify the completion requirement, the minimum length of the data frame in the Ethernet frame should not be less than 46 bytes, so as to ensure that the maximum data frame length of the 802.3 protocol is 1518 bytes, and the minimum value is 64 bytes. Festival.

In order to reduce the amount of forwarding, the detection data frame length in the embodiment of the present invention is set to 46 bytes, plus fields such as the preamble, delimiter, type, check code of the detection data frame, just reach the minimum of the Ethernet data frame The length is 64 bytes. The detection data frame of 46 bytes in the present invention can adopt the following format: "1111000011110000..." or "0xF0F0F0F0F0F0F0F0F0...". The detection data frame exemplified in the above embodiment is a relatively common format of the detection data frame in the embodiment of the present invention, and detection data frames in other formats are also applicable to the present invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (14)

1. a link automatic switching method, be applied to the automatic switching of the main/standby link that two switching devices set up by main/standby transmission port, it is characterized in that, the method comprises: After the first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device for M consecutive periods, it determines that the active link is faulty; wherein, the first switching device and the second switching device periodically send The other party sends the detection data frame; The first switching device closes the active link and enables the standby link to work; Wherein, M is a positive integer; the detection data frame is a specific data frame different from service data frames agreed in advance by the first switching device and the second switching device. 2. The method according to claim 1, wherein each switching device has a master/standby device port corresponding to a master/standby transmission port one by one, and the first switch device closes the active link, Enable backup link work, including: triggering the active device port of the first switching device to stop receiving service data frames, and triggering to close the active device port of the first switching device; The first switching device does not detect the electrical signal of the active device port for N consecutive periods, triggering the activation of the backup device port of the first switching device; The first switching device triggers enabling the standby transmission port of the first switching device to transmit service data frames, and periodically sends detection data frames to the second switching device through the standby transmission port; Wherein, N is a positive integer. 3. The method according to claim 2, further comprising: After the first switching device triggers the active device port to be closed continuously for X periods, the first device triggers the active device port to be turned on; The first switching device detects the electrical signal of the active device port for Y consecutive cycles, and triggers the active transmission port of the first switching device to send detection data frames to the second switching device for M consecutive cycles; The first switching device detects that the active transmission port has not received the detection data frame sent by the second switching device within the consecutive M periods, triggers to close the active port of the first switching device, and returns Trigger the active device port to shut down X cycle steps continuously; The first switching device detects that the active transmission port has received the detection data frame sent by the second switching device within the consecutive M periods, then determines that the active link is restored, and triggers the active link of the first switching device. periodically sending a detection data frame to the second switching device by using a transmission port; Wherein, X, Y, M are all positive integers, and X is not less than N. 4. The method of claim 3, further comprising: When it is detected that the active link recovers from failure and the backup circuit fails, switch back to the active link to work. 5. The method according to claim 4, characterized in that, specifically comprising: The first switching device detects that the backup transmission port has not received the detection data frame sent by the second switching device for L consecutive cycles, and determines that the backup link is faulty; The first switching device triggers the backup device port to stop receiving service data frames, and triggers to close the backup device port of the first switching device; The first switching device does not detect the electrical signal of the standby device port for P consecutive periods, triggering the activation of the active device port of the first switching device; The first switching device triggers enabling the primary transmission port of the first switching device to transmit service data frames, and periodically sends detection data frames to the second switching device through the standby transmission port; Among them, L and P are both positive integers. 6. The method according to claim 5, further comprising: The first switching device triggers the backup device port to be closed continuously for Z periods, and the first device triggers the backup device port to be turned on; The first switching device detects the electrical signal of the backup device port for Q consecutive cycles, and triggers the backup transmission port of the first switching device to send detection data frames to the second switching device for L consecutive cycles; The first switching device detects that the standby transmission port has not received the detection data frame sent by the second switching device in the continuous L cycles, triggers to close the standby device port of the first switching device, and returns to trigger the standby device port Close Z cycle steps consecutively; The first switching device detects that the backup transmission port receives the detection data frame sent by the second switching device in the continuous L cycles, then determines that the backup link is restored, and triggers the backup transmission port of the first switching device periodically sending a detection data frame to the second switching device; Among them, Z, L, Q are all positive integers, and Z is not less than P. 7. The method according to any one of claims 2 to 6, characterized in that, after the active device port of the first switching device is triggered to stop receiving the service data frame, the standby transmission port of the first switching device is triggered to transmit the service data frame Previously, also included: The first switching device detects that the active transmission port has received the service data frame sent by the second switching device side, forwards the service data frame from the active transmission port to the active device port, and the active device port sends and processes the service data frame . 8. A link automatic switching device, which is applied to the automatic switching of the main/standby link established by two switching devices through the main/standby transmission port, is characterized in that the device includes: The detection unit is configured to detect that the primary transmission port of the first switching device has not received the detection data frame sent by the second switching device for M consecutive cycles, and determine that the primary link is faulty; wherein, the first switching device and The second switching device periodically sends the detection data frame to the other party; M is a positive integer; the detection data frame is a specific type that is different from the service data frame and is pre-agreed by the first switching device and the second switching device. Data Frame; A switching unit, configured to close the active link and enable the standby link to work. 9. The device according to claim 8, wherein each switching device has a master/standby device port corresponding to the master/standby transmission port one-to-one, and the switching unit is specifically used for: triggering the active device port of the first switching device to stop receiving service data frames, and triggering to close the active device port of the first switching device; The detection unit is specifically configured to: not detect the electrical signal of the active device port of the first switching device for N consecutive periods; the switching unit is specifically configured to: trigger and activate the standby device port of the first switching device ; triggering the standby transmission port of the first switching device to transmit service data frames, and triggering the detection unit to periodically send detection data frames to the second switching device through the standby transmission port; Wherein, N is a positive integer. 10. The device according to claim 9, wherein the switching unit is further used for: After triggering the active device port to be closed for X consecutive cycles, trigger to open the active device port; The detection unit is further configured to detect the electrical signal of the main device port for Y consecutive cycles, and trigger the primary transmission port of the first switching device to send detection data frames to the second switching device for M consecutive cycles; The detecting unit is further configured to detect that the primary transmission port has not received the detection data frame sent by the second switching device within the consecutive M periods; the switching unit is further configured to trigger the shutdown of the first The active device port of the switching device; The detection unit is further configured to detect that the active transmission port receives a detection data frame sent by the second switching device within the consecutive M periods, then determine that the active link is restored; trigger the first switching device The primary transmission port periodically sends a detection data frame to the second switching device; Wherein, X, Y, M are all positive integers, and X is not less than N. 11. The device according to claim 10, wherein the switching unit is further used for: It is detected that the failure of the active link is recovered, and the backup circuit is faulty, switching back to work of the active link. 12. The device according to claim 11, wherein the detection unit is specifically used for: Detecting that the standby transmission port has not received the detection data frame sent by the second switching device for L consecutive cycles, and determining that the standby link is faulty; The switching unit is specifically configured to trigger the backup device port to stop receiving service data frames, and trigger to close the backup device port of the first switching device; The detection unit is specifically configured to detect no electrical signal of the standby device port for P consecutive periods; the switching unit is specifically configured to trigger the activation of the primary device port of the first switching device; trigger the activation of the first switching device port; The main transmission port of the switching device transmits the service data frame, and notifies the detection unit to periodically send the detection data frame to the second switching device through the standby transmission port; Among them, L and P are both positive integers. 13. The device according to claim 12, wherein the switching unit is further used for: Trigger the backup device port to close Z cycles continuously, and trigger the backup device port to open; The detection unit is also used to detect the electrical signal of the backup device port for Q consecutive cycles, and trigger the backup transmission port of the first switching device to send detection data frames to the second switching device for L consecutive cycles; The detection unit is specifically used to detect that the standby transmission port has not received the detection data frame sent by the second switching device in the continuous L cycles; the switching unit is used to trigger the shutdown of the standby transmission port of the first switching device. device port; The detection unit is specifically configured to detect that the backup transmission port receives the detection data frame sent by the second switching device in the continuous L cycles, then determine that the backup link is restored, and trigger the backup of the first switching device. The transmission port periodically sends detection data frames to the second switching device; Among them, Z, L, Q are all positive integers, and Z is not less than P. 14. The device according to any one of claims 8-13, wherein the switching unit is further used for: After the active port of the first switching device is triggered to stop receiving service data frames, before the standby transmission port of the first switching device is triggered to transmit service data frames, it is detected that the active transmission port of the first switching device receives the second switching device The service data frame sent by the side forwards the service data frame from the main transmission port to the main equipment port, and the main equipment port sends and processes the service data frame.