CN101272348A - Method and system for bandwidth control - Google Patents

Abstract

The present invention provides a method and system for bandwidth control, which monitors the cache of the switching network device by acquiring the cache status information of the switching network device, and when it is determined according to the buffer status information that data frame congestion or overflow occurs in the cache of the switching network device , adjusting the data frame sending bandwidth used by each virtual output queue (VOQ) according to the congestion or overflow situation. Therefore, a mechanism is provided during the data exchange process. If data frame congestion or overflow occurs in the cache of the switching network device, the data frame transmission bandwidth used by each VOQ can be adjusted in time to effectively avoid data loss during the data exchange process. Frame loss problem, to ensure the quality of service (QoS) of the data exchange business.

Description

Method and system for bandwidth control

technical field

The invention relates to network communication technology, in particular to a bandwidth control method and system.

Background technique

The switching network device is the core part of equipment such as modular routers and switches, and is responsible for data exchange between line cards at each port or slot. The composition of the existing switching network device is shown in Figure 1. The switching network device mainly includes a core switching unit (FU, Fabric Unit) and a switching access unit (FAU, FabricAccess Unit). Each FAU is responsible for the communication between the FU and each line card. Connection, the FU is connected to the packet processor (PP, Packet Processor) in each line card through each FAU, and is used to complete the data exchange between each line card. Wherein, the FAU can be set on the line card, and the FU can be set on the switching fabric board.

In order to reduce the cost of the switching network device and ensure high compatibility of the device, data exchange is usually performed in the form of non-fixed-length switching, that is, the line card adds a switching network frame header to the data frame and sends it directly to the switching network device. The data frame is sliced and reassembled, and the switching network device forwards the received data frame to a corresponding line card. For a clearer description, the line card that sends the data frame to the switching network device is called the incoming line card, the line card that receives the data frame forwarded by the switching network device is called the outgoing line card, and the direction from the incoming line card to the switching network device is called the is the uplink direction, and the direction from the switching network device to the outgoing line card is called the downlink direction.

The specific implementation is usually: multiple virtual output queues (VOQ, Virtual Output Queue) and output queues (OQ, Output Queue) are set for each line card in the switching network device, and multiple VOQs set for one line card correspond to different outgoing line card. Among them, in the uplink direction, the FAU sends the data frame sent by the incoming line card to the VOQ corresponding to the destination outgoing line card, and the VOQ sends its own data frame to the FU, and the FU forwards the received data frame to the corresponding VOQ of the destination outgoing line card. FAU, in the downlink direction, the FAU corresponding to the destination outgoing line card sends the received data frame to the OQ set for the destination outgoing line card, and the OQ sends its own data frame to the destination outgoing line card. Taking Figure 2 as an example, after receiving the data frame sent by line card 1 to line card 2, FAU 1 sends the data frame to the VOQ set for line card 1 and corresponding to line card 2 for buffering, reaching the preset When the first trigger condition is met, VOQ sends the data frame it caches to FU. After FU caches it, the FU forwards it to FAU 2. FAU 2 sends the received data frame to the OQ set for line card 2. When the preset second trigger condition is met, the OQ set for the line card 2 sends the data frame buffered by itself to the line card 2 . Wherein, the first trigger condition may be according to a preset time interval, or the data frame in the VOQ reaches a certain number, etc., and the second trigger condition may be according to a preset time interval, or, the data frame in the OQ reaches a certain number etc., which can be preset according to actual needs.

However, the switching network device using this non-fixed-length switching method only has the function of data exchange, does not have the scheduling function, and cannot adjust the transmission bandwidth of the data frame sent by each VOQ to the FU. Therefore, when a data frame occurs in the cache of the switching network device When frames are congested or overflowed, data frames may be lost, and the QoS of data exchange services cannot be guaranteed. For example, when the transmission bandwidth of the data frame sent from the FAU to the FU is too small, causing VOQ congestion, or when the transmission bandwidth of the data frame sent from the FAU to the FU is too large, causing the buffer overflow of the FU, etc., all of which will cause the loss of the data frame.

Contents of the invention

In view of this, the present invention provides a bandwidth control method and system, so as to guarantee the QoS of the data exchange service.

A method for bandwidth control, the method comprising:

Acquiring cache state information of the switching network device;

When it is determined according to the buffer state information that data frame congestion or overflow occurs in the buffer of the switching network device, the data frame sending bandwidth used by each virtual output queue VOQ is adjusted according to the congestion or overflow situation.

A bandwidth control system, the system includes: a centralized scheduler and a switching network device;

The centralized scheduler is used to obtain the cache state information of the switching network device; when it is determined according to the cache state information that data frame congestion or overflow occurs in the cache of the switching network device, according to the congestion or overflow situation, adjust The data frame sending bandwidth used by each VOQ in the switching network device;

The switching network device is configured to provide its own cache status information to the centralized scheduler.

A bandwidth control system, the system includes at least two FAUs; and each FAU includes: a cache information acquisition unit, a monitoring unit, and an adjustment unit;

The cache information obtaining unit is used to obtain the cache state information of the switching network device where the FAU is located;

The monitoring unit is configured to monitor the buffer status of the switching network device according to the buffer status information, and when it is determined according to the buffer status information that data frame congestion or overflow occurs in the buffer of the switching network device, send the The adjustment unit sends an adjustment notice;

The adjustment unit is configured to adjust the data frame transmission bandwidth used by each VOQ according to the congestion or overflow condition after receiving the adjustment notification.

It can be seen from the above technical solutions that the method and system provided by the present invention monitor the cache of the switching network device by acquiring the cache status information of the switching network device. or when overflowing, adjust the data frame sending bandwidth used by each VOQ according to the congestion or overflowing situation. Therefore, a mechanism is provided during the data exchange process. If data frame congestion or overflow occurs in the cache of the switching network device, the data frame transmission bandwidth used by each VOQ can be adjusted in time to effectively avoid data loss during the data exchange process. Frame loss problem, to ensure the QoS of the data exchange service.

Description of drawings

FIG. 1 is a structural diagram of a switching network device in the prior art;

Figure 2 is a schematic diagram of data exchange in the prior art!

FIG. 3 is a schematic diagram of a centralized bandwidth control method provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of an out-of-band method in a distributed bandwidth control method provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of an in-band method in a distributed bandwidth control method provided by an embodiment of the present invention;

FIG. 6 is a structural diagram of a centralized bandwidth control system provided by an embodiment of the present invention;

FIG. 7 is a structural diagram of a centralized scheduler provided by an embodiment of the present invention;

FIG. 8 is a structural diagram of a distributed bandwidth control system provided by an embodiment of the present invention;

Fig. 9 is a schematic diagram of the structure of the FAU provided by the embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The method provided by the present invention mainly includes: acquiring the cache state information of the switching network device; when it is determined according to the cache state information that data frame congestion or overflow occurs in the cache of the switching network device, adjusting The data frame sending bandwidth used.

Wherein, the method may acquire one or more of the following cache status information: VOQ status information, FU cache status information and OQ status information. That is, one or more of these state information are monitored.

According to the different execution subjects of this method, it can be divided into two types: centralized and distributed. Firstly, the centralized bandwidth control method is described in detail. Arrows indicate data flow.

First, the situation of monitoring the status of each VOQ is described: each FAU sends the status information of each VOQ set for the line card connected to itself to the centralized scheduler, and the centralized scheduler receives the status information of the VOQ sent by each FAU The state of each VOQ is monitored, and when the state information of a certain VOQ indicates that the length of the data frame queue in the VOQ exceeds a preset first length threshold, it is determined that the VOQ is congested.

When it is determined that VOQ is congested, the following two adjustment methods can be used:

First, the centralized scheduler determines the OQ corresponding to the congested VOQ, and determines whether the output bandwidth of the OQ is surplus, that is, whether the standard configuration bandwidth of the OQ is greater than the data frame bandwidth currently used by the OQ; if there is surplus, Then the difference between the standard configuration bandwidth of the OQ and the data frame transmission bandwidth currently used by the OQ can be allocated to each VOQ corresponding to the OQ according to the preset allocation strategy, and the adjustment information can be provided to the corresponding VOQ of the OQ. Each VOQ, each VOQ adjusts its own data frame transmission bandwidth according to the adjustment information. Wherein, the preset distribution strategy may be an average distribution strategy, a weighted average distribution strategy, and the like.

Second, the centralized scheduler determines that among other VOQs corresponding to the same OQ as the congested VOQ, there are VOQs with remaining transmission bandwidth, that is, VOQs whose standard configuration bandwidth is greater than the currently used data frame transmission bandwidth, will determine the remaining VOQs of these VOQs The bandwidth allocated to the congested VOQ, and the adjustment information is provided to each VOQ corresponding to the OQ, and each VOQ adjusts its own data frame transmission bandwidth according to the adjustment information.

The above two methods can also be used at the same time, that is, if the congestion problem cannot be solved after the allocation by the first method, the second method can be used again.

In this method, the adjustment of the sending bandwidth of each VOQ can be realized by setting a token bucket, and each FAU injects a token corresponding to the assigned sending bandwidth into the token bucket of each VOQ according to the sending bandwidth allocated for each VOQ , each VOQ controls its own sending bandwidth according to the number of tokens in its own token bucket. The centralized scheduler can first send the scheduling information to the corresponding FAU, and each FAU adjusts the token injection rate to the token bucket of the VOQ according to the received scheduling information, so as to realize the adjustment of the transmission bandwidth of each VOQ. This method can be adopted in the following embodiments, and will not be repeated one by one.

When monitoring the cache status of the FU, the FU sends the cache status information of the FU to the centralized scheduler, and the centralized scheduler can judge whether a cache overflow occurs in the FU according to the received cache information. Another way can also be used, each FAU sends the data frame transmission bandwidth currently used by each VOQ to the centralized scheduler, and the data frame transmission bandwidth currently used by each OQ, and determines the data frame transmission bandwidth currently used by each VOQ and the data frame transmission bandwidth used by each VOQ. If the difference between the sending bandwidth of the data frame currently used by the OQ is greater than the maximum buffer value of the FU, it is determined that the buffer overflow of the FU occurs.

When the centralized scheduler determines that FU buffer overflow occurs, it adjusts the data frame transmission bandwidth used by each VOQ to 0, and provides the adjustment information to each VOQ, and each VOQ adjusts its own data frame transmission bandwidth according to the adjustment information. For example, when the centralized scheduler determines that the FU buffer overflows, it can send a close (Close) command to each FAU, each FAU stops injecting tokens into the token bucket, and each VOQ stops sending data frames. When the FU cache returns to normal, the centralized scheduler sends an Open command to each FAU, and each FAU injects tokens into the token bucket at the original token injection rate, and each VOQ resumes sending bandwidth.

In addition, the centralized scheduler can also adopt a hierarchical adjustment method. If the centralized scheduler determines that the overflow degree of the FU buffer reaches the first standard, it will reduce the data frame transmission bandwidth used by each VOQ to the currently used data frame transmission bandwidth. Half, when the FU cache returns to normal, restore the sending bandwidth of each VOQ. If the centralized scheduler determines that the overflow degree of the FU cache reaches the second standard, then the data frame transmission bandwidth used by each VOQ is adjusted to 0, the data frame transmission of each VOQ is stopped, and when the FU cache returns to normal, the bandwidth of each VOQ is restored. send bandwidth. That is to say, when the FU buffer overflow situation is serious, the data frame transmission of each VOQ is stopped, and if the FU buffer situation is not serious, the data frame transmission bandwidth of each VOQ can be adjusted to half of the original one. Of course, the adjustment to 0 and the original half is just an example, and other adjustment ratios can also be used.

When monitoring the status of the OQ, each FAU sends the status information of the OQ it is connected to the centralized scheduler, and the centralized scheduler receives the status information of the OQ. When the status information of an OQ indicates that the queue length of the OQ is greater than When the second length threshold is set, it is determined that data frame congestion occurs in the OQ. At this time, the centralized scheduler can reduce the data frame transmission bandwidth of each VOQ corresponding to the congested OQ. For example, the centralized scheduler can send a close command to each FAU corresponding to the congested OQ, and each FAU stops the VOQ corresponding to the OQ. VOQ data frame transmission. When the OQ returns to normal, an open command is sent to each FAU to restore the sending bandwidth of each VOQ corresponding to the OQ.

The distributed bandwidth control method is described in detail below. The centralized bandwidth control method is to centralize the scheduling function on the centralized scheduler to complete it, while the distributed bandwidth control method is to distribute the scheduling function to each FAU. The distributed bandwidth control method can be divided into out-of-band and in-band according to the transmission mode of the adjustment information. The data channel transmits the adjustment information. When the data channel is multiplexed, two queues can be set in the data channel to transmit signaling and data frames respectively, and the priority of the two queues can be set. High priority Queues can be used for signaling. The structural form of the out-of-band type can be shown in Figure 4, and the structural form of the in-band type can be shown in Figure 5, wherein the single-line arrow indicates the signaling flow direction, and the double-line arrow indicates the data flow direction.

Firstly, the situation of monitoring the status of each VOQ is described: each FAU sends the status information of each VOQ set for the line card connected to itself to the FAU of the destination line card corresponding to each VOQ through a multiplexed data channel or a signaling switch , and receive the VOQ status information sent by the FAU with the line card connected to itself as the destination line card. Each FAU monitors the received status information of each VOQ, and when the status information of a certain VOQ indicates that the length of the data frame queue in the VOQ exceeds the preset first length threshold, it is determined that the VOQ is congested.

When a FAU determines that VOQ is congested, the following two adjustment methods can be used:

The first one is to determine whether the FAU with VOQ congestion occurs to determine whether the output bandwidth of the OQ connected to itself is surplus, that is, to judge whether the standard configuration bandwidth of the OQ is greater than the data frame bandwidth currently used by the OQ; if there is surplus, it can follow the preset According to the assigned allocation strategy, the difference between the standard configuration bandwidth of the OQ and the data frame transmission bandwidth currently used by the OQ is allocated to each VOQ corresponding to the OQ, and through the multiplexing data channel or signaling switch, the The adjustment information is provided to each VOQ corresponding to the OQ; each VOQ adjusts its data frame transmission bandwidth according to the adjustment information after receiving the adjustment information. Wherein, the preset distribution strategy may be an average distribution strategy, a weighted average distribution strategy, and the like.

The second type is to determine the FAU where the VOQ is congested. According to the received VOQ status information, determine the VOQ whose standard configuration bandwidth is greater than the currently used data frame transmission bandwidth, and compare the determined standard configuration bandwidth of the VOQ with the data currently used by the VOQ. The difference between frame transmission bandwidths is allocated to the VOQ that is congested, and the adjustment information is provided to each VOQ corresponding to the OQ through the multiplexed data channel or signaling switch, and each VOQ is adjusted according to the received adjustment information Its own data frame sending bandwidth.

The above two methods can also be used at the same time, that is, if the congestion problem cannot be solved after the allocation by the first method, the second method can be used again.

In this method, the adjustment of the sending bandwidth of each VOQ can be realized by setting a token bucket, and each FAU injects a token corresponding to the assigned sending bandwidth into the token bucket of each VOQ according to the sending bandwidth allocated for each VOQ , each VOQ controls its own sending bandwidth according to the number of tokens in its own token bucket. The centralized scheduler can first send the scheduling information to the corresponding FAU, and each FAU adjusts the token injection rate to the token bucket of the VOQ according to the received scheduling information, so as to realize the adjustment of the transmission bandwidth of each VOQ. This method can be adopted in the following embodiments.

When monitoring the buffer status of the FU, the FU sends the buffer status information of the FU to each FAU, and each FAU can judge whether the buffer overflow occurs in the FU according to the received buffer information.

When each FAU determines that the FU buffer overflow occurs, the data frame transmission bandwidth used by each VOQ of the line card connected to itself as the destination line card is adjusted to 0, and the adjustment information is provided to each VOQ, and each VOQ adjusts the bandwidth according to the adjustment The message adjusts its own data frame sending bandwidth. For example, when each FAU determines that the FU buffer overflow occurs, it can send a close (Close) command to the FAU with the line card connected to itself as the destination line card, each FAU stops injecting tokens into the token bucket, and each VOQ stops sending data frames . When the FU cache returns to normal, each FAU sends a re-open (Open) command to each FAU with the line card connected to itself as the destination line card, and each FAU injects tokens into the token bucket at the original token injection rate. VOQ restores the sending bandwidth.

In addition, a hierarchical adjustment method can also be adopted. If each FAU determines that the overflow degree of the FU buffer reaches the first standard, the data frame transmission bandwidth used by each VOQ of the line card connected to itself is reduced to the current used one. Half of the data frame transmission bandwidth, when the FU cache returns to normal, restore the transmission bandwidth of each VOQ of the line card connected to itself as the destination line card. If each FAU determines that the overflow degree of the FU cache reaches the second standard, then the data frame transmission bandwidth used by each VOQ of the line card connected to itself is adjusted to 0, and the data frame transmission of each VOQ is stopped, and the FU When the cache returns to normal, the transmission bandwidth of each VOQ is restored. That is to say, when the FU buffer overflow situation is serious, the data frame transmission of each VOQ is stopped, and if the FU buffer situation is not serious, the data frame transmission bandwidth of each VOQ can be adjusted to half of the original one. Of course, the adjustment to 0 and the original half is just an example, and other adjustment ratios can also be used.

When monitoring the status of the OQ, each FAU obtains the status information of the OQ connected to itself, and when the status information of the OQ indicates that the queue length of the OQ is greater than the set second length threshold, it is determined that the OQ has data frame congestion. At this time, the FAU that determines that the OQ is congested can reduce the data frame transmission bandwidth of each VOQ corresponding to the congested OQ, and provide adjustment information to each VOQ corresponding to the congested OQ through a multiplexed data channel or a signaling switch. Each VOQ adjusts its own data frame transmission bandwidth according to the received adjustment information. For example, the FAU may send a close command to each FAU corresponding to the OQ that transmits congestion, and each FAU stops sending data frames of the VOQ corresponding to the OQ after receiving the close command. When the OQ returns to normal, an open command is sent to each FAU to restore the sending bandwidth of each VOQ corresponding to the OQ.

In addition, each FAU can also send the data frame transmission bandwidth information currently used by the VOQ connected to itself to the FAU corresponding to the destination line card, and obtain the data frame transmission bandwidth information currently used by the OQ connected to itself; each FAU determines the current bandwidth of the OQ connected to itself. The difference between the data frame transmission bandwidth used and the received data frame transmission bandwidth sum currently used by each VOQ, when the determined difference is greater than 0, the difference is allocated to each corresponding OQ connected to itself VOQ. When the difference is greater than 0, that is, the data frame transmission bandwidth currently used by OQ is greater than the sum of the data frame transmission bandwidth currently used by the corresponding VOQ. Part of the redistribution, so as to fully utilize the bandwidth.

Wherein, the data frame transmission bandwidth currently used by the OQ may be the standard output bandwidth configured by the OQ, or the actual current transmission rate obtained by performing output speed measurement on the OQ set for the line card. If the PP has wire-speed processing capability, the OQ output data frame regardless of the packet size, the data frame transmission bandwidth currently used by OQ can remain constant, reaching the standard output bandwidth of the OQ configuration; if the PP does not have wire-speed processing capability, then The output bandwidth of the OQ is related to the packet size of the data frame. Therefore, it is necessary to measure the output speed of the OQ to obtain the actual current sending rate.

Initially, the present invention does not specifically limit the allocation method of each VOQ bandwidth. Usually, the output bandwidth of the OQ can be allocated to each VOQ corresponding to the OQ. The specific allocation can be average allocation, weighted average allocation, on-demand allocation or Methods such as allocation according to priority are not described in detail here.

The above is a detailed description of the method provided by the present invention, and the system provided by the present invention will be described in detail below. The system provided by the present invention can be divided into a centralized bandwidth control system and a distributed bandwidth control system, and the two systems will be described respectively below. FIG. 6 is a structural diagram of a centralized bandwidth control system provided by an embodiment of the present invention. In the figure, the single-line arrow indicates the signaling flow direction, and the double-line arrow indicates the data frame flow direction. As shown in Figure 6, the system mainly includes: a centralized scheduler and a switch network device.

The centralized scheduler is used to obtain the cache state information of the switching network device; when it is determined according to the cache state information that data frame congestion or overflow occurs in the cache of the switching network device, according to the congestion or overflow status, adjust the switching network device Data frame transmission bandwidth used by each VOQ.

The switch network device is used to provide the centralized scheduler with its own cache state information.

Wherein, the switch network device may include: FAU and VOQ set for each line card.

Each FAU is used to obtain the state information of each VOQ set for the line card connected to itself, and send the obtained state information of the VOQ to the centralized scheduler.

The VOQ is used to accept the adjustment of the data frame transmission bandwidth of the VOQ by the centralized scheduler.

The switching network device may further include: a FU, configured to send FU cache status information to the centralized scheduler.

The FU may be provided with a physical interface that provides FU cache status information to the centralized scheduler, such as peripheral component expansion interface (PCI) or GE.

The switch network device may further include: OQ set for each line card.

Each FAU can also be used to obtain the status information of the OQ set for the line card connected to itself, and provide the status information of the OQ to the centralized scheduler.

The switching network device may also include: a token bucket set for each VOQ, for storing tokens allocated for each VOQ;

Each FAU is also used to adjust the token injection rate into the token bucket of each VOQ according to the token injection rate corresponding to the adjusted data frame transmission bandwidth of each VOQ according to the adjusted data frame transmission bandwidth of each VOQ.

Each VOQ uses the sending bandwidth corresponding to the number of tokens in its own token bucket to send data frames.

That is to say, the process of the centralized scheduler providing the adjustment information to each VOQ can be realized by means of tokens, that is, the centralized scheduler sends the adjustment information to the FAU corresponding to each VOQ, and the FAU is adjusted according to the data frame of each VOQ Send the token injection rate corresponding to the bandwidth, adjust the rate of injecting tokens into the token buckets of each VOQ, and each VOQ uses the sending bandwidth corresponding to the number of tokens in its own token bucket to send data frames, so as to realize the VOQ Adjustment of data frame sending bandwidth.

The centralized scheduler in the system is described in detail below. FIG. 7 is a structural diagram of the centralized scheduler provided by the embodiment of the present invention. As shown in FIG. 7, the centralized scheduler includes: a status information acquisition unit 700, A monitoring unit 710 and an adjusting unit 720 .

The state information obtaining unit 700 is configured to obtain cache state information of switching network devices.

The monitoring unit 710 is configured to monitor the buffer status information, and send an adjustment notification to the adjustment unit 720 when it is determined according to the buffer status information that data frame congestion or overflow occurs in the buffer of the switching network device.

The adjustment unit 720 is configured to adjust the data frame transmission bandwidth used by each VOQ according to the congestion or overflow situation after receiving the adjustment notification.

Since the cache status information of the switching network device obtained by the centralized scheduler can be one or any combination of VOQ status information, FU cache status information, and OQ status information, the centralized scheduler can also be the following three: One or any combination of these structures:

The first type: when the cache status information acquired by the status information acquisition unit 700 is the status information of each VOQ, the monitoring unit 710 may include: a first judging subunit 711 and a first notification sending subunit 712 .

The first judging subunit 711 is configured to judge whether the length of the data frame queue in the VOQ exceeds a preset first length threshold according to the received status information of the VOQ.

The first notification sending subunit 712 is configured to determine that the VOQ is congested when the judgment result of the first judging subunit 711 is yes, and send a first adjustment notification to the adjustment unit 720 .

Correspondingly, the adjustment unit 720 may include: a first adjustment subunit 721 and a first adjustment information sending subunit 722 .

The first adjustment subunit 721 is configured to determine the OQ corresponding to the congested VOQ after receiving the first adjustment notification, and allocate the difference between the standard configuration bandwidth of the OQ and the data frame transmission bandwidth currently used by the OQ For each VOQ corresponding to the OQ, or determine the VOQ whose standard configuration bandwidth is greater than the currently used data frame transmission bandwidth among other VOQs corresponding to the same OQ as the congested VOQ, compare the determined standard configuration bandwidth of the VOQ with the current bandwidth of the VOQ The difference between the used data frame transmission bandwidths is allocated to the congested VOQ.

The first adjustment information sending subunit 722 is configured to provide the adjustment information of the first adjustment subunit 721 to each VOQ corresponding to the OQ.

The second type: when the cache status information acquired by the status information acquiring unit 700 is FU cache status information, the monitoring unit 710 may include: a second judging subunit 713 and a second notification sending subunit 714 .

The second judging subunit 713 is configured to judge whether FU buffer overflow occurs according to the received FU buffer status information.

The second notification sending subunit 714 is used to determine that the buffer overflow of the FU occurs when the judgment result of the second judgment subunit 713 is yes, and send a second adjustment notification to the adjustment unit 720; When the FU cache returns to normal, a recovery notification is sent to the adjustment unit 720 .

Correspondingly, the adjustment unit 720 may include: a second adjustment subunit 723 and a second adjustment information sending subunit 724 .

The second adjustment subunit 723 is configured to reduce the data frame transmission bandwidth used by each VOQ after receiving the second adjustment notification; and restore the data frame transmission bandwidth of each VOQ after receiving the recovery notification.

The second adjustment information sending subunit 724 is configured to provide the adjustment information of the second adjustment subunit 723 to each VOQ.

Thirdly, when the cache status information acquired by the status information acquiring unit 700 is OQ status information, the monitoring unit 710 may include: a third judging subunit 715 and a third notification sending subunit 716 .

The third judging subunit 715 is configured to judge whether the length of the data frame queue in the OQ exceeds a preset second length threshold according to the received status information of the OQ.

The third notification sending subunit 716 is used to determine that the OQ has data frame congestion when the judgment result of the third judging subunit 715 is yes, and sends the third adjustment notification to the adjustment unit 720; in the third judging subunit 715 When it is judged that the OQ returns to normal, a recovery notification is sent to the adjustment unit 720 .

Correspondingly, the adjustment unit 720 includes: a third adjustment subunit 725 and a third adjustment information sending subunit 726 .

The third adjustment subunit 725 is configured to reduce the data frame transmission bandwidth of each VOQ corresponding to the congested OQ after receiving the third adjustment notification; after receiving the recovery notification, restore the data frame transmission bandwidth of each VOQ corresponding to the OQ .

The third adjustment information sending subunit 726 is configured to provide the adjustment information of the third adjustment subunit 725 to each VOQ.

The above-mentioned centralized scheduler can be realized by using FPGA or application specific integrated circuit (ASIC, Application Specific Integrated Circuit).

FIG. 8 is a structural diagram of a distributed bandwidth control system provided by an embodiment of the present invention. In the figure, a single-line arrow indicates a signaling flow direction, and a double-line arrow indicates a data frame flow direction. As shown in FIG. 8, the system includes at least two FAUs set for each line card.

Each FAU obtains the cache status information of the switching network device where it is located, and when it is determined that data frame congestion or overflow occurs in the cache in the switching network, according to the congestion or overflow situation, adjust the VOQ of each VOQ of the line card connected to itself as the destination line card. Data frame sending bandwidth.

The cache status information of the switching network device acquired by each FAU may be one or any combination of VOQ status information, FU cache status information, and OQ status information. The specific structure and operation of each FAU will be described in detail in the structure shown in FIG. 9 .

The distributed bandwidth control system can be divided into two types: out-of-band and in-band. When the out-of-band structure is adopted, the system can also include: a signaling switch, used to send the status information of each VOQ connected to each FAU To the FAU of the destination line card corresponding to each VOQ, and forward the information that each FAU adjusts the data frame sending bandwidth of the VOQ to the corresponding VOQ.

When the in-band structure is adopted, the system may also include: FU, which is used to send the status information of each VOQ connected to each FAU to the FAU of the destination line card corresponding to each VOQ through a multiplexed data channel, and send Each FAU forwards the information about adjusting the data frame sending bandwidth of the VOQ to the corresponding VOQ; or, provides each FAU with FU buffer state information.

Similarly, the adjustment of the transmission bandwidth of each VOQ data frame can be done by means of tokens. At this time, the system can also include: a token bucket set for each VOQ, which is used to store tokens allocated for each VOQ.

Each FAU is also used to adjust the token injection rate into the token bucket of each VOQ according to the token injection rate corresponding to the adjusted data frame transmission bandwidth of each VOQ according to the adjusted data frame transmission bandwidth of each VOQ.

Each VOQ uses the sending bandwidth corresponding to the number of tokens in its own token bucket to send data frames.

The FAU structure in the above-mentioned distributed bandwidth control system is described in detail below. FIG. 9 is a schematic diagram of the FAU structure provided by the embodiment of the present invention. As shown in FIG. 9 , the FAU may include: a cache information acquisition unit 900 and a monitoring unit 910 and adjustment unit 920 .

The cache information acquiring unit 900 is configured to acquire cache status information of the switching network device where the FAU is located.

The monitoring unit 910 is configured to monitor the buffer status of the switching network device according to the buffer status information, and send an adjustment notification to the adjustment unit 920 when it is determined according to the buffer status information that data frame congestion or overflow occurs in the buffer of the switching network device.

The adjustment unit 920 is configured to adjust the data frame transmission bandwidth used by each VOQ according to the congestion or overflow situation after receiving the adjustment notification.

Also according to the acquired cache state information, the structure of the FAU may include one or any combination of the following three types:

Type 1: The cache information acquiring unit 900 includes: a first information sending subunit 901 and a first information acquiring subunit 902 .

The first information sending subunit 901 is configured to send the state information of each VOQ connected to the FAU to the FAU of the destination line card corresponding to each VOQ.

The first information acquiring subunit 902 is configured to receive VOQ status information sent by other FAUs whose destination line card is the line card connected to the FAU.

The monitoring unit 910 may include: a first judgment subunit 911 and a first notification subunit 912 .

The first judging subunit 911 is configured to judge whether the length of the data frame queue in the VOQ exceeds a preset first length threshold according to the received status information of the VOQ.

The first notification subunit 912 is configured to determine that the VOQ is congested when the determination result of the first determination subunit 911 is yes, and send a first adjustment notification to the adjustment unit 920 .

The adjustment unit 920 may include: a first adjustment subunit 921 and a first adjustment information sending subunit 922 .

The first adjustment subunit 921 is configured to allocate the difference between the standard configuration bandwidth of the OQ connected to the FAU and the data frame transmission bandwidth currently used by the OQ to each corresponding OQ after receiving the first adjustment notification. VOQ; or, determine the VOQ whose standard configuration bandwidth is greater than the currently used data frame transmission bandwidth, and allocate the difference between the determined standard configuration bandwidth of the VOQ and the data frame transmission bandwidth currently used by the VOQ to the congested VOQ.

The first adjustment information sending subunit 922 is configured to send the adjustment information of the first adjustment subunit 921 to each VOQ corresponding to the OQ.

The second type: the cache information acquiring unit 900 includes: a second information acquiring subunit 903, configured to receive the FU cache status information sent by the FU.

The monitoring unit 910 may include: a second judgment subunit 913 and a second notification subunit 914 .

The second judging subunit 913 is configured to judge whether FU buffer overflow occurs according to the FU buffer state information received by the second information acquiring subunit 903 .

The second notification subunit 914 is used to send a second adjustment notification to the adjustment unit 920 when the judgment result of the second judgment subunit 913 is yes; 920 Send a recovery notification.

The adjustment unit 920 includes: a second adjustment subunit 923 and a second adjustment information sending subunit 924 .

The second adjustment subunit 923 is configured to, after receiving the second adjustment notification, reduce the data frame transmission bandwidth of each VOQ whose destination line card is the line card connected to the FAU; after receiving the restoration notification, restore the data frame of each VOQ send bandwidth.

The second adjustment information sending subunit 924 is configured to send the adjustment information of the second adjustment subunit 923 to each VOQ.

The third type: the cache information acquisition unit 900 includes: a third information acquisition subunit 904, configured to receive the state information of the OQ connected to the FAU.

The monitoring unit 910 includes: a third judgment subunit 915 and a third notification subunit 916 .

The third judging subunit 915 is configured to judge whether the OQ queue length is greater than the set second length threshold according to the OQ status information acquired by the third information acquiring subunit 904 .

The third notification subunit 916 is used to send the third adjustment notification to the adjustment unit 920 when the judgment result of the third judgment subunit 915 is yes; when the third judgment subunit 915 judges that the state of the OQ returns to normal, send The adjustment unit 920 sends a recovery notification.

The adjustment unit 920 includes: a third adjustment subunit 925 and a third adjustment information sending subunit 926 .

The third adjustment subunit 925 is configured to reduce the data frame transmission bandwidth of each VOQ corresponding to the congested OQ after receiving the third adjustment notification; and restore the data frame transmission bandwidth of each VOQ after receiving the recovery notification.

The third adjustment information sending subunit 926 is configured to send the adjustment information of the third adjustment subunit 925 to each VOQ.

In addition, in the above three structures, the FAU may further include: a bandwidth information sending unit 931 , a bandwidth information acquiring unit 932 and a remaining status determining unit 933 .

The bandwidth information sending unit 931 is configured to send the data frame currently used by the VOQ connected to the FAU to send the bandwidth information to the FAU corresponding to the destination line card.

The bandwidth information obtaining unit 932 is configured to receive the data frame transmission bandwidth information currently used by the VOQ sent by other FAUs, and obtain the data frame transmission bandwidth information currently used by the OQ connected to the FAU where it is located.

Remaining status determination unit 933, for determining the difference between the data frame sending bandwidth information currently used by OQ and the sending bandwidth sum of data frame currently used by VOQ received by the bandwidth information acquisition unit, and when the determined difference is greater than 0, send to the adjustment unit 920 Send a fourth adjustment notification.

The adjustment unit 920 may further include: a fourth adjustment subunit 927 and a fourth adjustment information sending subunit 928 .

The fourth adjusting subunit 927 is configured to distribute the difference determined by the remaining status determining unit 933 to each VOQ corresponding to the OQ connected to the FAU.

The fourth adjustment information sending subunit 928 is configured to send the adjustment information of the fourth adjustment subunit 927 to each VOQ.

In addition, the FAU may also include: a token injection unit 934, configured to adjust the token injection rate corresponding to the adjusted data frame transmission bandwidth of each VOQ according to the adjusted data frame transmission bandwidth of the VOQ connected to the FAU. The rate at which tokens are injected into the token bucket of each VOQ.

The above-mentioned FAU can be realized by using FPGA or ASIC. In addition, during specific implementation, the functions of the above FAU may also be integrated into the PP of the line card for implementation.

It can be seen from the above description that the method and system provided by the present invention monitor the cache of the switching network device by acquiring the cache status information of the switching network device. When it is determined according to the cache status information that data frame congestion or When overflowing, adjust the data frame sending bandwidth used by each VOQ according to the congestion or overflow situation. Therefore, a mechanism is provided during the data exchange process. If data frame congestion or overflow occurs in the cache of the switching network device, the data frame transmission bandwidth used by each VOQ can be adjusted in time to effectively avoid data loss during the data exchange process. Frame loss problem, to ensure the QoS of the data exchange service.

Moreover, the method and system provided by the present invention provide specific monitoring and adjustment schemes for three possible situations that may occur in the switching network device, namely, VOQ congestion, FU buffer overflow, and OQ congestion, so as to avoid the occurrence of VOQ Data frame loss caused by congestion, FU buffer overflow, and OQ congestion.

In addition, the present invention essentially superimposes the control plane on the data exchange plane of the switching network, thereby realizing the adjustment of the data frame transmission bandwidth of each VOQ, and specifically provides two system structures, that is, a centralized bandwidth control system and a Distributed bandwidth control system.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (28)

1. A method of bandwidth control, the method comprising:

acquiring cache state information of a switching network device;

and when the data frame congestion or overflow occurs in the cache of the switching network device is determined according to the cache state information, adjusting the data frame sending bandwidth used by each virtual output queue VOQ according to the congestion or overflow condition.

2. The method of claim 1, wherein the caching of the switching network device comprises: VOQ, core switch unit FU buffer, or output queue OQ.

3. The method of claim 2, wherein the obtaining the buffer status information of the switching network device is performed by a centralized scheduler.

4. The method of claim 3, wherein obtaining the buffer status information of the switching network device comprises: the centralized scheduler receives the state information of each VOQ connected with the centralized scheduler, which is sent by each exchange access unit FAU;

the determining that data frame congestion occurs in a buffer of the switching network device includes: when the state information of the VOQ indicates that the length of a data frame queue in the VOQ exceeds a preset first length threshold, determining that the VOQ is congested;

the adjusting of the data frame transmission bandwidth used by each VOQ includes: the centralized scheduler determines an OQ corresponding to a congested VOQ, allocates a difference value between a standard configuration bandwidth of the OQ and a data frame sending bandwidth currently used by the OQ to each VOQ corresponding to the OQ, and provides the adjustment information to each VOQ corresponding to the OQ, and each VOQ adjusts the data frame sending bandwidth thereof according to the adjustment information; or, determining a VOQ with a standard configuration bandwidth larger than a currently used data frame transmission bandwidth in other VOQs corresponding to the same OQ with the congested VOQ, allocating a difference value between the determined standard configuration bandwidth of the VOQ and the currently used data frame transmission bandwidth of the VOQ to the congested VOQ, and providing the adjustment information to each VOQ corresponding to the OQ, wherein each VOQ adjusts the data frame transmission bandwidth thereof according to the adjustment information; or a combination of the two.

5. The method of claim 3, wherein obtaining the buffer status information of the switching network device comprises: and the centralized scheduler receives the FU buffer state information sent by the FU.

6. The method of claim 3, wherein obtaining the buffer status information of the switching network device comprises: the centralized scheduler acquires a data frame sending bandwidth currently used by each VOQ and a data frame sending bandwidth currently used by each OQ, determines a difference value between the data frame sending bandwidth currently used by each VOQ and the data frame sending bandwidth currently used by each OQ, and acquires the buffer state information of the FU according to the determined difference value;

the determining that the data frame overflow occurs in the buffer of the switching network device includes: determining that a buffer overflow of the FU occurs when the determined difference is greater than a maximum buffer value of the FU.

7. The method according to claim 5 or 6, wherein the adjusting the data frame transmission bandwidth used by each VOQ comprises: when the centralized scheduler determines that FU buffer overflow occurs, reducing data frame sending bandwidth used by each VOQ, providing the adjustment information to each VOQ, and adjusting the data frame sending bandwidth of each VOQ according to the adjustment information; or,

if the centralized scheduler determines that the overflow degree of the FU buffer reaches a first standard, reducing the data frame sending bandwidth used by each VOQ to be half of the currently used data frame sending bandwidth; if the overflow degree of the FU buffer memory reaches the second standard, adjusting the data frame sending bandwidth used by each VOQ to be 0, providing the distribution information for each VOQ, and adjusting the data frame sending bandwidth of each VOQ according to the adjustment information;

the method further comprises the following steps: and when the centralized scheduler determines that the FU cache is recovered to be normal, recovering the transmission bandwidth of each VOQ.

8. The method of claim 3, wherein obtaining the buffer status information of the switching network device comprises: the centralized scheduler receives OQ state information which is sent by each FAU and connected with the centralized scheduler;

the determining that data frame congestion occurs in a buffer of the switching network device includes: when the state information of the OQ indicates that the queue length of the OQ is larger than a set second length threshold, determining that data frame congestion occurs to the OQ;

the adjusting of the data frame transmission bandwidth used by each VOQ includes: the centralized controller reduces the data frame sending bandwidth of each VOQ corresponding to the congested OQ, provides the adjustment information for each VOQ, and the VOQ adjusts the data frame sending bandwidth of the VOQ according to the adjustment information;

the method further comprises the following steps: and when the centralized controller determines that the OQ is recovered to be normal, recovering the transmission bandwidth of each VOQ corresponding to the OQ.

9. The method of claim 2, wherein the obtaining the buffer status information of the switching network device is performed by each FAU.

10. The method of claim 9, wherein obtaining the buffer status information of the switching network device comprises:

each FAU sends the state information of each VOQ connected with the FAU to the FAU of a target line card corresponding to each VOQ through a multiplexing data channel or a signaling exchanger, and receives the state information of the VOQ sent by the FAU taking the line card connected with the FAU as the target line card;

the determining that data frame congestion occurs in a buffer of the switching network device includes: when the state information of the VOQ indicates that the length of a data frame queue in the VOQ exceeds a preset first length threshold, determining that the VOQ is congested;

the adjusting of the data frame transmission bandwidth used by each VOQ includes: determining that an FAU with VOQ congestion distributes a difference value between standard configuration bandwidth of an OQ connected with the FAU and data frame sending bandwidth currently used by the OQ to each VOQ corresponding to the OQ, and providing the adjustment information to each VOQ corresponding to the OQ through a multiplexing data channel or a signaling exchanger, wherein each VOQ adjusts the data frame sending bandwidth of the FAU according to the adjustment information; or, determining the FAU with the congested VOQ, determining the VOQ with the standard configuration bandwidth larger than the currently used data frame transmission bandwidth according to the received VOQ state information, allocating the difference between the determined VOQ standard configuration bandwidth and the currently used data frame transmission bandwidth of the VOQ to the congested VOQ, and providing the adjustment information to each VOQ corresponding to the OQ through a multiplexing data channel or a signaling exchanger, wherein each VOQ adjusts the data frame transmission bandwidth thereof according to the adjustment information; or a combination of the two.

11. The method of claim 9, wherein obtaining the buffer status information of the switching network device comprises: each FAU receives FU buffer state information sent by the FU;

the adjusting of the data frame transmission bandwidth used by each VOQ includes: when each FAU determines that FU buffer overflow occurs, reducing data frame sending bandwidth used by each VOQ of a line card taking a line card connected with each FAU as a target line card, and providing the adjustment information to each VOQ through a multiplexing data channel or a signaling exchanger, wherein each VOQ adjusts the data frame sending bandwidth of each VOQ according to the adjustment information; or, if each FAU determines that the overflow degree of the FU buffer memory reaches the first standard, reducing the data frame transmission bandwidth used by each VOQ of the line card taking the own connected line card as the target line card to half of the currently used data frame transmission bandwidth; if the overflow degree of the FU buffer memory is determined to reach the second standard, adjusting the data frame sending bandwidth used by each VOQ of the line card taking the own connecting line card as the target line card to be 0, providing the distribution information to each VOQ through a multiplexing data channel or a signaling exchanger, and adjusting the data frame sending bandwidth of each VOQ according to the adjustment information;

the method further comprises the following steps: and when each FAU determines that the FU cache is recovered to be normal, recovering the transmission bandwidth of each VOQ of the line card which takes the line card connected with the FAU as a target line card.

12. The method of claim 9, wherein obtaining the buffer status information of the switching network device comprises: each FAU acquires the state information of the OQ connected with the FAU;

the determining that data frame congestion occurs in a buffer of the switching network device includes: when the state information of the OQ indicates that the queue length of the OQ is larger than a set second length threshold, determining that data frame congestion occurs to the OQ;

the adjusting of the data frame transmission bandwidth used by each VOQ includes: determining that the FAU with the OQ congestion reduces the data frame sending bandwidth of each VOQ corresponding to the OQ with the congestion, and providing the adjustment information to each VOQ corresponding to the OQ with the congestion through a multiplexing data channel or a signaling exchanger, wherein each VOQ adjusts the data frame sending bandwidth thereof according to the adjustment information;

the method further comprises the following steps: and when the FAU which determines that the OQ congestion occurs determines that the OQ is recovered to be normal, recovering the transmission bandwidth of each VOQ corresponding to the OQ.

13. The method of claim 4, 7, 8, 10 or 11, further comprising: each FAU injects tokens into a token bucket of each VOQ connected with each FAU according to the token injection rate corresponding to the data frame transmission bandwidth allocated to each VOQ; each VOQ controls the sending bandwidth of the VOQ according to the number of tokens in the token bucket of the VOQ;

providing the adjustment information to the VOQs comprises: and providing the adjustment information to FAUs corresponding to the VOQs, and adjusting the token injection rate of the token bucket of the VOQs by the FAUs receiving the adjustment information according to the adjustment information.

14. A system for bandwidth control, the system comprising: a centralized scheduler and a switching network device;

the centralized scheduler is used for acquiring cache state information of the switching network device; when the congestion or overflow of the data frame in the cache of the switching network device is determined according to the cache state information, the data frame sending bandwidth used by each VOQ in the switching network device is adjusted according to the congestion or overflow condition;

and the switching network device is used for providing self cache state information for the centralized scheduler.

15. The system of claim 14, wherein the switching network means comprises: FU and each VOQ;

the FU is used for sending FU buffer state information to the centralized scheduler;

each VOQ is configured to receive adjustment of the data frame transmission bandwidth of the VOQ by the centralized scheduler.

16. The system of claim 14, wherein the switching network means comprises: FAU, VOQ and OQ set for each line card;

each FAU is used for acquiring the state information of each VOQ connected with the FAU and/or the state information of the OQ connected with the FAU, and sending the state information of each VOQ and/or the state information of the OQ connected with the FAU to the centralized scheduler;

the VOQ is configured to receive the adjustment of the centralized scheduler on the data frame transmission bandwidth of the VOQ.

17. The system according to claim 15 or 16, wherein the switching network device further comprises: a token bucket set for each VOQ for storing tokens allocated for each VOQ;

each FAU is further used for adjusting the rate of token injection into the token bucket of each VOQ according to the token injection rate corresponding to the adjusted data frame sending bandwidth of each VOQ;

each VOQ transmits a data frame using a transmission bandwidth corresponding to the number of tokens in its token bucket.

18. The system of claim 14, wherein the centralized scheduler comprises: the device comprises a state information acquisition unit, a monitoring unit and an adjusting unit;

the state information acquiring unit is used for acquiring the cache state information of the switching network device;

the monitoring unit is used for monitoring the cache state information and sending an adjustment notice to the adjusting unit when determining that data frame congestion or overflow occurs in the cache of the switching network device according to the cache state information;

and the adjusting unit is used for adjusting the data frame sending bandwidth used by each VOQ according to the congestion or overflow condition after receiving the adjustment notification.

19. The system according to claim 18, wherein when the buffer status information acquired by the status information acquiring unit is status information of each VOQ, the monitoring unit includes: a first judging subunit and a first notification sending subunit;

the first judging subunit is configured to judge, according to the received state information of the VOQ, whether the length of the data frame queue in the VOQ exceeds a preset first length threshold;

the first notification sending subunit is configured to, when the determination result of the first determining subunit is yes, determine that the VOQ is congested, and send a first adjustment notification to the adjusting unit;

the adjusting unit includes: a first adjustment subunit and a first adjustment information sending subunit;

the first adjusting subunit is configured to, after receiving the first adjustment notification, determine an OQ corresponding to a congested VOQ, allocate a difference between a standard configuration bandwidth of the OQ and a data frame transmission bandwidth currently used by the OQ to each VOQ corresponding to the OQ, or determine, of other VOQs corresponding to the same OQ as the congested VOQ, a standard configuration bandwidth of the VOQ that is greater than the data frame transmission bandwidth currently used, and allocate a difference between the standard configuration bandwidth of the determined VOQ and the data frame transmission bandwidth currently used by the VOQ to the congested VOQ;

and the first adjustment information sending subunit is configured to provide the adjustment information of the first adjustment subunit to each VOQ corresponding to the OQ.

20. The system according to claim 18, wherein when the buffer status information acquired by the status information acquiring unit is FU buffer status information, the monitoring unit comprises: a second judgment subunit and a second notification transmission subunit;

the second judgment subunit is used for judging whether FU cache overflow occurs or not according to the received FU cache state information;

the second notification sending subunit is configured to determine that buffer overflow of the FU occurs when the determination result of the second determining subunit is yes, and send a second adjustment notification to the adjusting unit; when the second judging subunit judges that the FU cache is recovered to be normal, a recovery notification is sent to the adjusting unit

The adjusting unit includes: a second adjustment subunit and a second adjustment information sending subunit;

the second adjusting subunit is configured to reduce a data frame sending bandwidth used by each VOQ after receiving the second adjustment notification; after receiving the recovery notification, recovering the data frame transmission bandwidth of each VOQ;

and the second adjustment information sending subunit is configured to provide the adjustment information of the second adjustment subunit to each VOQ.

21. The system according to claim 18, wherein when the cache status information acquired by the status information acquiring unit is OQ status information, the monitoring unit includes: a third judging subunit and a third notification sending subunit;

the third judging subunit is configured to judge, according to the received state information of the OQ, whether the length of the data frame queue in the OQ exceeds a preset second length threshold;

the third notification sending subunit is configured to, when the determination result of the third determining subunit is yes, determine that data frame congestion occurs in the OQ, and send a third adjustment notification to the adjusting unit; when the third judging subunit judges that the OQ is recovered to normal, a recovery notification is sent to the adjusting unit;

the adjusting unit includes: a third adjustment subunit and a third adjustment information sending subunit;

the third adjusting subunit is configured to reduce, after receiving the third adjustment notification, a data frame transmission bandwidth of each VOQ corresponding to the congested OQ; after receiving the recovery notification, recovering the data frame transmission bandwidth of each VOQ corresponding to the OQ;

and the third adjustment information sending subunit is configured to provide the adjustment information of the third adjustment subunit to each VOQ.

22. A system for bandwidth control, the system comprising at least two FAUs; and, each of the FAUs includes: the device comprises a cache information acquisition unit, a monitoring unit and an adjusting unit;

the cache information obtaining unit is used for obtaining cache state information of the switching network device where the FAU is located;

the monitoring unit is used for monitoring the cache state of the switching network device according to the cache state information, and sending an adjustment notice to the adjusting unit when determining that data frame congestion or overflow occurs in the cache of the switching network device according to the cache state information;

and the adjusting unit is used for adjusting the data frame sending bandwidth used by each VOQ according to the congestion or overflow condition after receiving the adjustment notification.

23. The system according to claim 22, wherein the cache information obtaining unit comprises: a first information sending subunit and a first information acquiring subunit;

the first information sending subunit sends the state information of each VOQ connected with the FAU to the FAU of the destination line card corresponding to each VOQ;

the first information acquisition subunit is used for receiving the VOQ state information sent by other FAUs of the line card which is connected with the FAU and used as a target line card;

the monitoring unit includes: a first judging subunit and a first notifying subunit;

the first judging subunit is configured to judge, according to the received state information of the VOQ, whether the length of the data frame queue in the VOQ exceeds a preset first length threshold;

the first notification subunit is configured to, when the determination result of the first determination subunit is yes, determine that the VOQ is congested, and send a first adjustment notification to the adjustment unit;

the adjusting unit includes: a first adjustment subunit and a first adjustment information sending subunit;

the first adjusting subunit is configured to, after receiving the first adjustment notification, allocate a difference between a standard configuration bandwidth of an OQ connected to the FAU and a data frame transmission bandwidth currently used by the OQ to each VOQ corresponding to the OQ; or determining a VOQ with a standard configuration bandwidth larger than the currently used data frame transmission bandwidth, and allocating the difference value between the determined VOQ standard configuration bandwidth and the VOQ currently used data frame transmission bandwidth to the VOQ with congestion;

and the first adjustment information sending subunit sends the adjustment information of the first adjustment subunit to each VOQ corresponding to the OQ.

24. The system according to claim 22, wherein the cache information obtaining unit comprises: the second information acquisition subunit is used for receiving FU buffer state information sent by the FU;

the monitoring unit includes: a second judging subunit and a second notifying subunit;

the second judging subunit is configured to, according to the FU buffer status information received by the second information obtaining subunit, judge whether FU buffer overflow occurs;

the second notification subunit is configured to send a second adjustment notification to the adjustment unit when the determination result of the second determination subunit is yes; when the second judging subunit judges that the FU cache is restored to normal, sending a restoration notification to the adjusting unit;

the adjusting unit includes: a second adjustment subunit and a second adjustment information sending subunit;

the second adjusting subunit is configured to reduce, after receiving the second adjustment notification, a data frame transmission bandwidth of each VOQ of the line card using the line card connected to the FAU as a destination line card; after receiving the recovery notification, recovering the data frame transmission bandwidth of each VOQ;

and the second adjustment information sending subunit is configured to send the adjustment information of the second adjustment subunit to each VOQ.

25. The system according to claim 22, wherein the cache information obtaining unit comprises: a third information obtaining subunit, configured to receive state information of the OQ connected to the FAU;

the monitoring unit includes: a third judging subunit and a third notifying subunit;

the third judging subunit is configured to judge whether the queue length of the OQ is greater than a set second length threshold according to the OQ state information acquired by the third information acquiring subunit;

the third notification subunit is configured to send a third adjustment notification to the adjustment unit when the determination result of the third determination subunit is yes; when the third judging subunit judges that the state of the OQ returns to normal, a recovery notification is sent to the adjusting unit;

the adjusting unit includes: a third adjustment subunit and a third adjustment information sending subunit;

the third adjusting subunit is configured to reduce, after receiving the third adjustment notification, a data frame transmission bandwidth of each VOQ corresponding to the congested OQ; after receiving the recovery notification, recovering the data frame transmission bandwidth of each VOQ;

and the third adjustment information sending subunit is configured to send the adjustment information of the third adjustment subunit to each VOQ.

26. The system of claim 23, 24 or 25, further comprising: a token bucket set for each VOQ for storing tokens allocated for each VOQ;

the FAU further includes: and the token injection unit is used for adjusting the rate of injecting the tokens into the token bucket of each VOQ according to the adjusted data frame sending bandwidth of the VOQ connected with the FAU and the token injection rate corresponding to the adjusted data frame sending bandwidth of each VOQ.

27. The system of any one of claims 22 to 25, further comprising: and the signaling exchanger is used for sending the state information of each VOQ connected with each FAU to the FAU of the destination line card corresponding to each VOQ, and forwarding the information of each FAU for adjusting the data frame sending bandwidth of the VOQ to the corresponding VOQ.

28. The system of any one of claims 22 to 25, further comprising: and the FU is used for sending the state information of each VOQ connected with each FAU to the FAU of the destination line card corresponding to each VOQ through the multiplexing data channel, and forwarding the information of each FAU for adjusting the data frame sending bandwidth of the VOQ to the corresponding VOQ.

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