阅读说明：本技术 基于动态虚拟门限的缓存管理方法 (Cache management method based on dynamic virtual threshold ) 是由 张冰 凌楠玮 张奭 赵辉 张�诚 于 2020-03-13 设计创作，主要内容包括：本发明公开了一种基于动态虚拟门限的缓存管理方法,主要解决现有技术在高缓存利用率情况下不能保证各个队列门限设置公平的问题。其实现方案是：1)初始化各队列缓存管理参数；2)判断当前数据帧能否进入缓存空间,并判断缓存管理器是否需要丢弃数据帧,当没有数据帧到达缓存空间时本次缓存管理操作结束；3)对于没有被缓存丢弃的数据帧进入缓存空间；4)每隔T时刻修改一次各队列的虚拟门限值；5)出队调度器在每个周期取走缓存中的数据帧,返回2)。本发明只在缓存满的时候才丢弃数据帧且为每个队列设置了动态虚拟门限缓存,具有缓存空间利用率高,各个队列之间公平性较好的优点,可用于网络交换设备。(The invention discloses a cache management method based on a dynamic virtual threshold, which mainly solves the problem that the prior art can not ensure the fairness of the threshold setting of each queue under the condition of high cache utilization rate. The implementation scheme is as follows: 1) initializing each queue buffer management parameter; 2) judging whether the current data frame can enter a cache space or not, judging whether a cache manager needs to discard the data frame or not, and finishing the cache management operation when no data frame reaches the cache space; 3) entering a buffer space for the data frames which are not discarded by the buffer; 4) modifying the virtual threshold value of each queue every T moments; 5) the dequeue scheduler takes the data frame in the buffer away every cycle, return 2). The invention discards the data frame only when the buffer is full and sets the dynamic virtual threshold buffer for each queue, has the advantages of high utilization rate of buffer space and better fairness among the queues, and can be used for network switching equipment.)

1. A cache management method based on a dynamic virtual threshold is characterized by comprising the following steps:

(1) initializing cache management service parameters:

setting P users N of buffer management service_iI is from 1 to P;

let belong to user N_iThe data frames are stored in high, medium and low 3 priority queues, and the virtual threshold value of each priority queue is Q_ijJ is from 1 to 3;

let belong to user N_iEach priority queue has a weighted proportion R of the number of data frames_ij；

Setting the number of data frame frames which can be accommodated in the whole cache space as M, and the number of data frame frames which can be accommodated in the whole cache space in real time as MN;

setting the dynamic virtual threshold adjustment period of cache management as T, wherein T is more than 0;

setting the proportionality coefficient of the static initial value of the virtual threshold as w, wherein w is more than 0 and less than 1;

let belong to user N_iThe average weighted ratio of the number of data frames in the last period of each priority queue is RO_ij；

Let belong to user N_iThe average weighted proportion value of the data frame number of each priority queue in the period is RN_ij；

Let belong to user N_iOf the last period of each of the high, medium and low priority queues, and the average weighted ratio RO of the number of data frames of the last period of each of the high, medium and low priority queues_i1、RO_i2、RO_i3All initial values of (1) are 0;

let belong to user N_iEach priority queue of (1)_ij；

Designing the proportional coefficient t of the average weighted proportional value of the frame number of the data frames belonging to one period of the high, medium and low priority queues of P users₁Calculating the average weighted ratio of the frame numbers of the data frames belonging to one period of the high, medium and low priority queues of P users as t₂；

Designing weighted proportion R of data frame number belonging to high, medium and low priority queues of P users_i1、R_i2、R_i3Respectively is k₁、k₂、k₃；

(2) The data frame arrives at the cache, if the MN is equal to M at the moment, the cache space is executed fully (3), otherwise, the cache space is executed not fully (6);

(3) the real-time queue length l of the queue to which the data frame arriving at the buffer belongs_ijVirtual threshold value Q of queue to which the queue belongs_ijComparing: if l is_ij≥Q_ijDiscarding the data frame arriving at the buffer if l_ij＜Q_ijIf so, executing (4);

(4) judging whether all low priority queues belonging to P users have queue length l_i3Exceeds its virtual threshold value Q_i3The queue (2) of (1): if yes, selecting the queue and discarding a data frame of the selected queue, and then executing (6), otherwise, executing (5);

(5) judging whether queue length l exists in all medium priority queues belonging to P users_i2Exceeds its virtual threshold value Q_i2The queue (2) of (1): if yes, selecting the queue and discarding a data frame of the selected queue, and then executing (6); otherwise, selecting a queue length l from all high priority queues belonging to P users_i3Exceeds its virtual threshold value Q_i3And discarding a data frame of the selected queue, and then performing (6);

(6) the data frame arriving at the buffer memory enters a buffer memory space;

(7) judging whether a data frame arriving at the buffer exists: if the data frame arriving at the buffer memory exists, executing (8), otherwise, the dequeue scheduler takes out all the data frames in the buffer memory, and finishing the buffer memory management operation;

(8) modifying the virtual threshold value of the queue every T time, namely if the current time is an integer multiple of T, modifying the virtual threshold value of the queue, and executing (9); otherwise, executing (2);

(9) in the scheduling period, the weighting proportion R of the number of the data frames belonging to the high, medium and low priority queues of the P users is calculated respectively_i1、R_i2、R_i3；

(10) According to the result of (9), calculating the average weighted proportion value RN of the frame number of the data frame in the period belonging to the high, medium and low priority queues of the P users respectively_i1、RN_i2、RN_i3：

RN_i1＝(1-w)×RO_i1+w×R_i1，

RN_i2＝(1-w)×RO_i2+w×R_i2，

RN_i3＝(1-w)×RO_i3+w×R_i3；

(11) According to the result of (10), respectively calculating the dynamic virtual threshold values Q of high, medium and low priority queues belonging to P users_i1、Q_i2、Q_i3：

Q_i1＝RN_i1×t₁+t₂，Q_i2＝RN_i2×t₁+t₂，Q_i3＝RN_i3×t₁+t₂；

(12) According to the result of (10), calculating average weighted ratio value RO of data frame number of one period on high, medium and low priority queues belonging to P users_i1、RO_i2、RO_i3：

RO_i1＝RN_i1，RO_i2＝RN_i2，RO_i3＝RN_i3；

(13) And (4) the dequeue scheduler fetches all data frames in the buffer and returns to the step (2).

2. The method of claim 1, wherein in (9) the weighted ratio R of the number of data frames in the high, medium and low priority queues of P users is calculated_i1、R_i2、R_i3Calculated by the following formula:

wherein, a is the frame number of high priority data frames which arrive at all users in the current period, b is the frame number of medium priority data frames which arrive at all users in the current period, c is the frame number of low priority data frames which arrive at all users in the current period, and m is the frame number of low priority data frames which arrive at all users in the current period_i1Belonging to user N for the arrival of the current period_iNumber of high priority data frames, m_i2Belonging to user N for the arrival of the current period_iNumber of medium priority data frames, m_i3Belonging to user N for the arrival of the current period_iThe number of low priority data frames.

3. The method of claim 1, wherein the data frames arriving at the buffer in (2) are fixed length data frames.

Technical Field

The invention belongs to the technical field of communication, and particularly relates to a dynamic virtual threshold cache management method which can be used for network switching equipment.

Background

The cache management is a key technology in the network switching equipment, and a good cache management method can improve the utilization efficiency of cache resources in the switching equipment and reduce the frame loss rate of network switching data frames.

The existing cache management algorithm is mainly divided into three types, namely a static threshold strategy, a dynamic threshold strategy and a PUSH-OUT strategy, wherein:

and the static threshold strategy allocates a buffer with a fixed size for each queue, and data frames arriving at the queue can enter the queue buffer when the queue has residual buffer space, and the data frames arriving at the queue are discarded when the queue has no residual buffer space. The method is simple and easy to implement, but the buffer strategy may cause the situation that part of the queues have to discard the arriving data frames because the number of the arriving data frames occupies the queue buffer fully, and the situation that a large amount of buffer space is idle because the number of the arriving data frames is too small, thereby wasting the buffer resources and increasing the discarding probability of the data frames.

And the dynamic threshold strategy is that the size of the buffer distributed to the queues is dynamically changed according to the size of the real-time service flow of each queue. The cache strategy enables the cache size to adapt to the condition of a network in real time, but the change value of the cache size is difficult to accurately match the cache size occupied by the real-time service flow, so that the dynamically allocated cache size is often larger than the cache size required by the actual service flow, and therefore, a part of cache space is idle by the cache strategy, and the use efficiency of the cache is influenced.

The PUSH-OUT strategy allows data frames belonging to a queue without buffer space to be stored in a queue with residual buffer space, and the strategy discards the data frames only when the whole buffer space is full, so that the strategy has a lower frame loss rate. However, the strategy cannot match real-time data frame information of each queue in real time, and when the whole buffer space is full and a data frame is discarded, the data frame cannot be discarded according to the historical queue lengths of other queues, so that certain fairness is lacked.

Disclosure of Invention

The present invention aims to provide a cache management method based on a dynamic virtual threshold to ensure fairness among users as much as possible while ensuring a low dropping rate of data frames in view of the above-mentioned deficiencies of the prior art.

In order to achieve the purpose, the technical scheme of the invention comprises the following steps:

(1) initializing cache management service parameters:

setting P users N of buffer management service_iI is from 1 to P;

let belong to user N_iThe data frames are stored in high, medium and low 3 priority queues, and the virtual threshold value of each priority queue is Q_ijJ is from 1 to 3;

let belong to user N_iEach priority queue has a weighted proportion R of the number of data frames_ij；

Setting the number of data frame frames which can be accommodated in the whole cache space as M, and the number of data frame frames which can be accommodated in the whole cache space in real time as MN;

setting the dynamic virtual threshold adjustment period of cache management as T, wherein T is more than 0;

setting the proportionality coefficient of the static initial value of the virtual threshold as w, wherein w is more than 0 and less than 1;

let belong to user N_iThe average weighted ratio of the number of data frames in the last period of each priority queue is RO_ij；

Let belong to user N_iThe average weighted proportion value of the number of data frames of the current period of each priority queue isRN_ij；

Let belong to user N_iOf the last period of each of the high, medium and low priority queues, and the average weighted ratio RO of the number of data frames of the last period of each of the high, medium and low priority queues_i1、RO_i2、RO_i3All initial values of (1) are 0;

let belong to user N_iEach priority queue of (1)_ij；

Designing the proportional coefficient t of the average weighted proportional value of the frame number of the data frames belonging to one period of the high, medium and low priority queues of P users₁Calculating the average weighted ratio of the frame numbers of the data frames belonging to one period of the high, medium and low priority queues of P users as t₂；

Designing weighted proportion R of data frame number belonging to high, medium and low priority queues of P users_i1、R_i2、R_i3Respectively is k₁、k₂、k₃；

(2) The data frame arrives at the cache, if the MN is equal to M at the moment, the cache space is executed fully (3), otherwise, the cache space is executed not fully (6);

(3) the real-time queue length l of the queue to which the data frame arriving at the buffer belongs_ijVirtual threshold value Q of queue to which the queue belongs_ijComparing: if l is_ij≥Q_ijDiscarding the data frame arriving at the buffer if l_ij＜Q_ijIf so, executing (4);

(4) judging whether all low priority queues belonging to P users have queue length l_i3Exceeds its virtual threshold value Q_i3The queue (2) of (1): if yes, selecting the queue and discarding a data frame of the selected queue, and then executing (6), otherwise, executing (5);

(5) judging whether queue length l exists in all medium priority queues belonging to P users_i2Exceeds its virtual threshold value Q_i2The queue (2) of (1): if yes, selecting the queue and discarding a data frame of the selected queue, and then executing (6); otherwise, in all high priority queues belonging to P usersOptionally a queue length l therein_i3Exceeds its virtual threshold value Q_i3And discarding a data frame of the selected queue, and then performing (6);

(6) the data frame arriving at the buffer memory enters a buffer memory space;

(7) judging whether a data frame arriving at the buffer exists: if the data frame arriving at the buffer memory exists, executing (8), otherwise, the dequeue scheduler takes out all the data frames in the buffer memory, and finishing the buffer memory management operation;

(8) modifying the virtual threshold value of the queue every T time, namely if the current time is an integer multiple of T, modifying the virtual threshold value of the queue, and executing (9); otherwise, executing (2);

(9) in the scheduling period, the weighting proportion R of the number of the data frames belonging to the high, medium and low priority queues of the P users is calculated respectively_i1、R_i2、R_i3；

(10) According to the result of (9), calculating the average weighted proportion value RN of the frame number of the data frame in the period belonging to the high, medium and low priority queues of the P users respectively_i1、RN_i2、RN_i3：

RN_i1＝(1-w)×RO_i1+w×R_i1，

RN_i2＝(1-w)×RO_i2+w×R_i2，

RN_i3＝(1-w)×RO_i3+w×R_i3；

(11) According to the result of (10), respectively calculating the dynamic virtual threshold values Q of high, medium and low priority queues belonging to P users_i1、Q_i2、Q_i3：

Q_i1＝RN_i1×t₁+t₂，Q_i2＝RN_i2×t₁+t₂，Q_i3＝RN_i3×t₁+t₂；

(12) According to the result of (10), calculating average weighted ratio value RO of data frame number of one period on high, medium and low priority queues belonging to P users_i1、RO_i2、RO_i3：

RO_i1＝RN_i1，RO_i2＝RN_i2，RO_i3＝RN_i3；

(13) And (4) the dequeue scheduler fetches all data frames in the buffer and returns to the step (2).

Compared with the prior art, the invention has the following advantages:

first, since the present invention discards the data frame only when the entire buffer space is full, the utilization efficiency of the buffer space can be improved, and the discarding probability of the data frame can be reduced.

Secondly, because the invention sets the dynamic virtual threshold for each user queue according to the size of the historical use buffer space of different user queues, when the whole buffer space is full and the data frame has to be discarded, the buffer manager can discard the data frame of the queue with part of the queue length exceeding the virtual threshold according to the size of the virtual threshold of each user queue, thereby improving the fairness among the user queues.

Drawings

FIG. 1 is a general flow chart of an implementation of the present invention;

fig. 2 is a network topology of the present invention.

Detailed Description

The following describes in detail the embodiments and effects of the present invention with reference to the drawings.

Referring to fig. 1, the implementation steps of this embodiment are as follows:

step 1, initializing cache management service parameters.

Setting P users N of buffer management service_iIn this embodiment, the cache management service is provided for 2 users N_iI is from 1 to 2;

let belong to user N_iThe data frames are stored in high, medium and low 3 priority queues, and the virtual threshold value of each priority queue is Q_ijJ is from 1 to 3;

let belong to user N_iEach priority queue has a weighted proportion R of the number of data frames_ij；

Setting the number of data frames which can be accommodated in the whole cache space as M, the number of data frames which can be accommodated in the whole cache space in real time as MN, and setting the whole cache space without data frames, namely MN at the initial moment;

setting the dynamic virtual threshold adjustment period of cache management as T, wherein T is more than 0;

setting the proportionality coefficient of the static initial value of the virtual threshold as w, wherein w is more than 0 and less than 1;

let belong to user N_iThe average weighted ratio of the number of data frames in the last period of each priority queue is RO_ij；

Let belong to user N_iThe average weighted proportion value of the data frame number of each priority queue in the period is RN_ij；

Let belong to user N_iOf the last period of each of the high, medium and low priority queues, and the average weighted ratio RO of the number of data frames of the last period of each of the high, medium and low priority queues_i1、RO_i2、RO_i3All initial values of (1) are 0;

let belong to user N_iEach priority queue of (1)_ij；

Designing the proportional coefficient t of the average weighted proportional value of the frame number of the data frames belonging to one period of the high, medium and low priority queues of P users₁Calculating the average weighted ratio of the frame numbers of the data frames belonging to one period of the high, medium and low priority queues of P users as t₂。

Designing weighted proportion R of data frame number belonging to high, medium and low priority queues of P users_i1、R_i2、R_i3Respectively is k₁、k₂、k₃。

And 2, constructing a network topology.

Referring to fig. 2, the network topology is composed of one master user and a plurality of slave users. The network topology of this example consists of one master user N₀And two slave users N₁、N₂The data frame is sent from a master user to two slave users, and the cache management is positioned in a master user N₀In (1).

This embodiment is generallyThe duration is three cycle durations, and each cycle duration T is 1088 us. Master user N of each cycle₀Needs to be sent to the first subordinate subscriber N₁The number of data frames is shown in Table 1, and each period is a primary user N₀Needs to be sent to the second subordinate subscriber N₂The number of data frame of (2) is shown in table 2.

TABLE 1N₀Needs to be sent to N₁Number of data frames of

TABLE 2N₀Needs to be sent to N₂Number of data frames of

And 3, judging the cache entering condition of the arriving data frame.

After the data frame with fixed length arrives at the buffer memory, whether the data frame can enter the buffer memory space is judged:

if the number MN of data frame frames contained in the whole cache space in real time is less than the number M of data frame frames contained in the whole cache space, the data frame can enter the cache space, and the step 7 is executed;

and if the number of data frame frames MN which can be accommodated in the whole cache space in real time exceeds the number of data frame frames M which can be accommodated in the whole cache space, executing the step 4.

In the embodiment of the present invention, the number of data frame frames M that the entire buffer space can accommodate is 100.

And 4, judging whether to discard the data frame arriving at the buffer.

The real-time queue length l of the queue to which the data frame arriving at the buffer belongs_ijVirtual threshold value Q of queue to which the queue belongs_ijComparing:

if the real-time queue length l of the queue to which the buffered data frame belongs is reached_ijExceeding the virtual threshold value Q of the associated queue_ijIf yes, discarding the data frame arriving at the buffer;

if the arrival is slowReal-time queue length l of queue to which stored data frame belongs_ijNot reaching the virtual threshold Q of the queue_ijThen step 5 is performed.

And 5, comparing the length of the low-priority queue with the virtual threshold value of the queue.

Judging whether it belongs to N₁、N₂Whether there is a queue length l in all low priority queues of a user_i3Exceeds its virtual threshold value Q_i3The queue (2) of (1): if so, the queue is selected and a data frame of the selected queue is discarded, and then step 7 is performed, otherwise step 6 is performed.

And 6, comparing the lengths of the medium and high priority queues with the virtual threshold value of the queues.

Judging whether it belongs to N₁、N₂Whether there is a queue length l in all medium priority queues of a user_i2Exceeds its virtual threshold value Q_i2The queue (2) of (1): if yes, selecting the queue and discarding a data frame of the selected queue, and then executing step 7; otherwise, in the case of belonging to N₁、N₂Optionally selecting a queue length l from all high priority queues of a user_i3Exceeds its virtual threshold value Q_i3And discards a data frame of the selected queue, and then performs step 7.

And 7, entering the data frame reaching the buffer into a buffer space.

In the embodiment of the invention, the sum of the number of the data frames in the first period is less than 100, so that all the data frames in the period can enter the buffer space. The sum of the number of the data frames in the second period is less than 100, so that all the data frames in the period can enter the buffer space. When the third period reaches the first 99 data frames, the number MN of data frames held in the whole cache space in real time is 99 smaller than the number M of data frames held in the whole cache space, which is 100, and the data frames can also enter the cache space. 4 arriving after the third period belong to user N₂Because the number of data frames MN that can be accommodated in the whole cache space in real time is not less than the number of data frames M that can be accommodated in the whole cache space, and belongs to the user N₂Of low priority data framesQueue real-time queue length l₂₃40 exceeding the virtual threshold value Q of the associated queue₂₃These 4 data frames are therefore discarded, 6.

And 8, judging the situation that the data frame reaches the buffer memory.

Judging whether a data frame arriving at the buffer exists: if there are more data frames arriving in the buffer, step 9 is executed, otherwise, the dequeue scheduler fetches all data frames in the buffer, and the buffer management operation is finished.

In the embodiment of the present invention, the buffered data frame is not reached only after the last data frame of the third period reaches the buffer, so that at this time, the dequeue scheduler fetches all the data frames in the buffer, and the buffer management operation is finished. After other data frames arrive in the buffer, the data frames arrive in the buffer, and step 9 is executed.

And 9, judging whether to modify the virtual threshold of the queue.

Modifying the virtual threshold value of the queue every T time, namely if the current time is an integer multiple of T, modifying the virtual threshold value of the queue, and executing the step 10; otherwise, returning to the step 3.

In the embodiment of the present invention, only when the last moment of the first period and the last moment of the second period are integer multiples of T, the virtual threshold of the queue needs to be modified, step 10 is executed, and when the first period, the second period, and the other moments of the third period are, the step 3 is returned to.

Step 10, calculating the value of N₁、N₂Weighted proportion R of data frame number of high, medium and low priority queues of user_i1、R_i2、R_i3。

Is of N₁、N₂Weighted proportion R of data frame number of high, medium and low priority queues of user_i1、R_i2、R_i3Calculated by the following formula:

wherein, a is the frame number of high priority data frames which arrive at all users in the current period, b is the frame number of medium priority data frames which arrive at all users in the current period, c is the frame number of low priority data frames which arrive at all users in the current period, and m is the frame number of low priority data frames which arrive at all users in the current period_i1Belonging to user N for the arrival of the current period_iNumber of high priority data frames, m_i2Belonging to user N for the arrival of the current period_iNumber of medium priority data frames, m_i3Belonging to user N for the arrival of the current period_iThe number of low priority data frames.

If the period belongs to N₁、N₂The high, medium and low priority data frame numbers a, b and c of the user are all 0, and belong to N₁、N₂Weighted proportion R of data frame number of high, medium and low priority queues of user₁₁、R₁₂、R₁₃、R₂₁、R₂₂、R₂₃Are all 0.

In an embodiment of the present invention, the calculation belongs to N₁、N₂Weighted ratio R of data frame number of high, medium and low priority queues of user_i1、R_i2、R_i3Coefficient of proportionality k₁＝3、k₂＝2、k₃1. Calculated as belonging to N in the first period₁、N₂The weighting ratios of the number of data frames of the three priority queues of the user high, medium and low are shown in table 3, for example. Calculated as belonging to N for the second period₁、N₂The weighting ratios of the number of data frames of the three priority queues of the user high, medium and low are shown in table 4, for example.

TABLE 3 frame number weighting ratio of data frames calculated in the first period

TABLE 4 frame number weighting ratio of data frames calculated in the second period

And 11, calculating the average weighted proportion value of the frame numbers of the data frames in the period.

Respectively calculating the N-values according to the result of step 10₁、N₂Average weighted proportion value RN of frame number of data frame in current period of high, medium and low priority queue of user_i1、RN_i2、RN_i3：

RN_i1＝(1-w)×RO_i1+w×R_i1，

RN_i2＝(1-w)×RO_i2+w×R_i2，

RN_i3＝(1-w)×RO_i3+w×R_i3；

In the embodiment of the invention, the proportionality coefficient w of the static initial value of the virtual threshold is 0.5, and the first period is calculated to belong to N₁、N₂The average weighted ratio of the frame numbers of the data frames in the period of the high, middle and low priority queues of the user is shown in table 5. Calculated as belonging to N for the second period₁、N₂The average weighted ratio of the data frame numbers of the current period of the user's high, middle and low priority queues is shown in table 6.

TABLE 5 average weighted ratio of data frame number calculated in the first period

TABLE 6 average weighting ratio of data frames in the second period

And step 12, calculating a dynamic virtual threshold value of the queue.

Respectively calculating the attributes according to the result of the step 11In N₁、N₂Dynamic virtual threshold value Q of user high, medium and low priority queue_i1、Q_i2、Q_i3：

Q_i1＝RN_i1×t₁+t₂，Q_i2＝RN_i2×t₁+t₂，Q_i3＝RN_i3×t₁+t₂；

In the embodiment of the invention, the N belongs to₁、N₂The proportionality coefficient of average weighted proportionality value of data frame number of one period on user high, medium and low priority queues is t₁70 to N₁、N₂The fixed offset coefficient of the average weighted proportion value of the data frame number of one period on the high, medium and low priority queues of the user is t₂5. Calculated as belonging to N in the first period₁、N₂The dynamic virtual threshold values of the user high, medium and low priority queues are shown in table 7. Calculated as belonging to N for the second period₁、N₂The dynamic virtual threshold values of the user high, medium and low priority queues are shown in table 8.

TABLE 7 dynamic virtual threshold values calculated for the first cycle

TABLE 8 dynamic virtual threshold values calculated for the second cycle

Step 13, calculating the average weighted ratio value RO of the number of data frames in the last period of the queue_i1、RO_i2、RO_i3。

Respectively calculating the N-belongings according to the results of the step 11₁、N₂Average weighted ratio value RO of data frame number of one period on user high, medium and low priority queue_i1、RO_i2、RO_i3：

RO_i1＝RN_i1，RO_i2＝RN_i2，RO_i3＝RN_i3；

In the embodiment of the present invention, the average weighting ratio of the number of frames of the data frame in the previous period calculated in the first period is shown in table 9. The average weighting ratio of the data frame numbers in the previous period calculated in the second period is shown in table 10.

TABLE 9 average weighting ratio of the number of data frames in the previous cycle calculated in the first cycle

TABLE 10 average weighting ratio of the data frames in the previous period calculated in the second period

And step 14, the dequeue scheduler takes out all the data frames in the buffer and returns to step 3.

In the embodiment of the invention, the first period dequeue scheduler takes out all data frames in the buffer, returns to the step 3 and starts the second period; and the dequeue scheduler in the second period takes out all the data frames in the buffer, returns to the step 3 and starts a third period.

The foregoing description is only a specific example of the present invention and is not intended to limit the invention, so that it will be apparent to those skilled in the art that modifications and variations in form and detail may be made without departing from the principles and structures of the invention, but such modifications and variations are within the scope of the invention as defined by the appended claims.