WO2020125647A1

WO2020125647A1 - Data retransmission method, device, and system

Info

Publication number: WO2020125647A1
Application number: PCT/CN2019/126073
Authority: WO
Inventors: 张龙; 黄凡夫; 王兴鹤
Original assignee: 杭州海康威视数字技术股份有限公司
Priority date: 2018-12-17
Filing date: 2019-12-17
Publication date: 2020-06-25
Also published as: CN111327402A; CN111327402B

Abstract

The present disclosure relates to a data retransmission method, a device and a system, belonging to the field of data transmission technology. Said method comprises: upon detection of a packet loss event, sending, to a sending end, a retransmission request for a lost data packet; acquiring an RTT, and determining, on the basis of the RTT, a retransmission parameter threshold; and when a retransmission duration has elapsed since the retransmission request was sent, if no data packet is received, sending, to the sending end, a retransmission request for the data packet, updating the RTT, and proceeding to the process of determining the retransmission parameter threshold on the basis of the RTT; and when the numerical value of the retransmission parameter reaches the corresponding retransmission parameter threshold, if no data packet is received, stopping sending a retransmission request for the data packet. The present disclosure can easily shorten the total time consumed by retransmission, avoiding a long wait time for a lost data packet, and improving the flexibility of data transmission.

Description

Method, device and system for retransmitting data

This application requires the priority of the Chinese patent application filed on December 17, 2018 with the application number 201811544881.8 and the invention titled "Method, Device and System for Retransmitting Data", the entire contents of which are incorporated by reference in this application.

Technical field

The present disclosure relates to the field of data transmission technology, and in particular, to a method, device, and system for retransmitting data.

Background technique

In the process of transmitting data in real time, due to the instability of the network, a packet loss event occurs in the transmitted data packet. At the receiving end, the sequence number of the lost data packet can be determined based on the sequence number of the received data packet. Subsequently, the receiving end may send a retransmission request to the sending end, and the retransmission request carries the sequence number of the lost data packet. After receiving the retransmission request, the sending end can find whether there is a missing data packet in the cache based on the sequence number of the missing data packet, if there is a missing data packet in the cache, then obtain the missing data packet and send the missing data packet to the receiving end . In the above process, due to the instability of the network, it is still not certain that the sending end will be able to receive the retransmission request sent by the receiving end. Similarly, it cannot be sure that the receiving end will be able to receive the lost data packet returned by the sending end. After the receiver sends the retransmission request, no response is received.

Therefore, for the receiving end, after sending out the retransmission request, it cannot wait for the lost data packet returned by the sending end indefinitely. In practical applications, after the receiver sends a retransmission request, if it has not received a lost packet after waiting for RTT (Round-Trip Time), it will send a retransmission request to the receiver again. The RTT duration is calculated by the receiving end according to the current network condition and a preset estimation algorithm according to a preset period. The value of the RTT duration indicates the expected duration of the retransmission request from the receiving end to the sending end and the sending end to return a lost packet one round trip. In the case of poor network conditions, the RTT duration is longer, in the case of better network conditions , RTT duration is shorter. NPQ (Network Protocol Quality, network protocol quality library) specifies the specific method of calculating the RTT duration.

The receiving end will repeat the process described above until it receives a lost data packet or the value of the retransmission parameter corresponding to the same retransmission request exceeds the corresponding preset retransmission parameter threshold. Among them, the retransmission parameters include the total retransmission time and the number of retransmissions. The preset retransmission parameter threshold corresponding to the total retransmission time is the total retransmission time threshold, and the preset retransmission corresponds to the number of retransmissions. The parameter threshold is the threshold of retransmission times. The threshold for the total retransmission time duration can be a fixed value, or it can be the maximum length of time that you can wait for a lost packet when the network conditions are poor. The threshold of the number of times of retransmission may also be a fixed value such as 10 times. When the total retransmission consumption duration corresponding to the same retransmission request is greater than the total retransmission consumption duration threshold, or the number of retransmissions corresponding to the same retransmission request exceeds the threshold of the number of retransmissions, it may stop continuing to send the retransmission request to the receiving end.

In the process of implementing the present disclosure, the inventor found that there are at least the following problems:

In the case of poor network conditions, the RTT time is long and it is easy to lose packets. The receiving end often requires a long total retransmission time to receive the lost packet returned, even in some cases, after the retransmission timeout , Still cannot receive the lost packet returned. Therefore, in the application scenarios of real-time data transmission, such as video conference application scenarios, using the above retransmission mechanism in the case of poor network conditions will cause a longer time to wait for the lost data packets, and the flexibility of data transmission is more difference.

Summary of the invention

In order to overcome the problems in the related art, the present disclosure provides the following technical solutions:

According to a first aspect of an embodiment of the present disclosure, a method for retransmitting data is provided. The method includes:

When a packet loss event is detected, a retransmission request for the lost data packet is sent to the sender;

Obtain the RTT duration and determine the retransmission parameter threshold based on the RTT duration;

When the retransmission duration is reached after the retransmission request is sent, if the data packet is not received, the RTT duration is updated, and the process of determining the retransmission parameter threshold based on the RTT duration is performed;

When the value of the retransmission parameter reaches the corresponding threshold of the retransmission parameter, if the data packet is not received, stop sending the retransmission request of the data packet.

Optionally, the retransmission parameters include the total retransmission time and/or the number of retransmissions, and the threshold of the retransmission parameter corresponding to the total retransmission time is the threshold of the total retransmission time and the number of retransmissions The corresponding threshold of the retransmission parameter is the threshold of the number of retransmissions.

Optionally, the threshold value of the retransmission parameter is a threshold value of the total consumption time of the retransmission. The acquiring the RTT duration and determining the threshold of the retransmission parameter based on the RTT duration includes:

Obtain the RTT duration, determine the retransmission duration corresponding to the RTT duration, and determine the product of the retransmission duration corresponding to the RTT duration and the first reference number of retransmissions;

The sum of the product and the preset reserved duration is determined as a total consumption duration threshold for retransmission.

Optionally, after obtaining the RTT duration, the method further includes:

Based on the correspondence relationship between the preset RTT duration range and the reference retransmission times, determine the first reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs, wherein in the correspondence, the larger the value of the RTT duration range corresponds to The fewer the number of retransmissions.

Optionally, the threshold of the retransmission parameter is a threshold of the number of retransmissions, and the acquiring the RTT duration, and determining the threshold of the retransmission parameter based on the RTT duration includes:

Obtain the RTT duration, and determine the second reference retransmission number corresponding to the RTT duration range to which the acquired RTT duration belongs based on the correspondence relationship between the preset RTT duration range and the reference retransmission times, wherein, in the correspondence, the RTT duration range The larger the value, the fewer the retransmission times;

Based on the comparison result of the second reference retransmission times and the third reference retransmission times determined when the retransmission request was sent last time, the threshold value of the retransmission times is determined.

Optionally, the determining the threshold of the number of retransmissions based on the comparison result of the second reference number of retransmissions and the third reference number of retransmissions determined when the retransmission request was sent last time includes:

If the second reference retransmission number is greater than or equal to the previously determined third reference retransmission number, determine the second reference retransmission number as the retransmission number threshold;

If the second reference retransmission number is less than the third reference retransmission number and the retransmission number is greater than or equal to the second reference retransmission number, the retransmission number is determined as a threshold of retransmission times;

If the second reference retransmission count is less than the third reference retransmission count and the retransmitted count is less than the second reference retransmission count, then the second reference retransmission count is determined as the retransmission count threshold.

Optionally, the acquiring the RTT duration, based on the correspondence between the preset RTT duration range and the reference retransmission times, determining the second reference retransmission count corresponding to the RTT duration range to which the acquired RTT duration belongs includes:

Get RTT duration;

If the type of the data packet is in the preset type set, then based on the first correspondence between the preset RTT duration range and the reference retransmission times, determine the second reference weight corresponding to the RTT duration range to which the acquired RTT duration belongs Transmission times

If the type of the data packet is not in the preset type set, based on the second correspondence between the preset RTT duration range and the reference retransmission times, determine the second corresponding to the RTT duration range to which the acquired RTT duration belongs Reference number of retransmissions, where the number of reference retransmissions corresponding to the same RTT duration range in the first correspondence is greater than or equal to the number of reference retransmissions corresponding to the second correspondence.

According to a second aspect of the embodiments of the present disclosure, a method for retransmitting data is provided. The method includes:

When it is detected that the data packet has been sent and stored in the buffer, the RTT duration is obtained, and based on the RTT duration, the first data storage reference duration is determined;

Determine a data storage duration threshold based on the first data storage reference duration and the second data storage reference duration determined when the previous data packet was stored in the cache;

Delete data packets that have been stored in the cache for longer than the data storage duration threshold;

Update the RTT duration and go to the process of acquiring the RTT duration when it is detected that the data packet has been sent and stored in the buffer.

Optionally, the determining the data storage duration threshold based on the first data storage reference duration and the second data storage reference duration determined when the previous data packet was stored in the cache includes:

The data storage duration threshold is determined based on the first data storage reference duration, the second data storage reference duration determined when the previous data packet was stored in the cache, and the pre-acquired reservation duration.

Optionally, the determining the data storage duration threshold based on the first data storage reference duration, the second data storage reference duration determined when the previous data packet was stored in the cache, and the pre-acquired reservation duration includes: :

Calculating the time difference between the time point when the current data packet is stored in the cache and the time point when the previous data packet is stored in the cache;

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is less than the second data storage reference duration, the second data storage reference duration is obtained in advance The sum of the reserved time is determined as the data storage time threshold;

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is greater than or equal to the second data storage reference duration, it is determined that the first data storage reference duration is equal to A duration difference between the second data storage reference durations, determining a product between the duration difference and a preset scale factor, and determining a sum between the product and the first data storage reference duration , The sum of the sum value and the reserved duration is determined as the data storage duration threshold;

If the first data storage reference duration is greater than the second data storage reference duration, the sum of the first data storage reference duration and the reserved duration is determined as a data storage duration threshold.

Optionally, the method further includes:

The reserved duration is determined based on the frame rate of the video frame to which the data packet belongs.

According to a third aspect of the embodiments of the present disclosure, an apparatus for retransmitting data is provided. The apparatus includes:

The sending module is used to send a retransmission request for the lost data packet to the sending end when a packet loss event is detected;

The determining module is used to obtain the RTT duration, and determine the retransmission parameter threshold based on the RTT duration;

The update module is used to update the RTT duration when the data packet is not received when the retransmission request is reached after the retransmission request is sent, and go to the process of determining the retransmission parameter threshold based on the RTT duration;

The stopping module is configured to stop sending the retransmission request of the data packet if the value of the retransmission parameter reaches the corresponding threshold value of the retransmission parameter, if the data packet is not received.

Optionally, the threshold of the retransmission parameter is a threshold of the total retransmission duration, and the determining module is configured to:

Optionally, the determination module is also used to:

Optionally, the threshold of the retransmission parameter is a threshold of the number of retransmissions, and the determination module is configured to:

Optionally, the determination module is configured to:

If the second reference retransmission times are less than the third reference retransmission times and the retransmission times are greater than or equal to the second reference retransmission times, the retransmission times are determined as a threshold of retransmission times;

Optionally, the determination module is configured to:

Get RTT duration;

According to a fourth aspect of the embodiments of the present disclosure, an apparatus for retransmitting data is provided. The apparatus includes:

The determining module is used to obtain the RTT duration when it is detected that the data packet has been sent and stored in the cache, and determine the first data storage reference duration based on the RTT duration; based on the first data storage reference duration and the previous data packet storage The second data storage reference duration determined when entering the cache, to determine the data storage duration threshold;

A deletion module, configured to delete a data packet that has been stored in the cache for more than the data storage duration threshold;

The update module is used to update the RTT duration and go to the process of acquiring the RTT duration when it is detected that the data packet is sent and stored in the buffer.

Optionally, the determination module is configured to:

Optionally, the determination module is also used to:

According to a fifth aspect of the embodiments of the present disclosure, a system for retransmitting data is provided. The system includes a sending end and a receiving end, where:

The receiving end is used to send a retransmission request of the lost data packet to the sending end when a packet loss event is detected; obtain the RTT duration, determine the retransmission parameter threshold based on the RTT duration; During the transmission time, if the data packet is not received, the RTT time is updated, and the process of determining the retransmission parameter threshold based on the RTT time is performed; when the value of the retransmission parameter reaches the corresponding retransmission parameter threshold, if If the data packet is not received, stop sending the retransmission request of the data packet;

The sending end is used to obtain the RTT duration when it is detected that the data packet has been sent and stored in the cache, and determine the first data storage reference duration based on the RTT duration; based on the first data storage reference duration and the previous data The second data storage reference duration determined when the packet is stored in the cache to determine the data storage duration threshold; deleting the data packets that have been stored in the cache for longer than the data storage duration threshold; updating the RTT duration , Go to the process of acquiring the RTT duration when it is detected that the data packet has been sent and stored in the buffer.

According to a sixth aspect of the embodiments of the present disclosure, there is provided a receiving end, the receiving end includes a processor, a communication interface, a memory, and a communication bus, wherein:

The processor, the communication interface, and the memory complete communication with each other through the communication bus;

The memory is used to store computer programs;

The processor is configured to execute the program stored on the memory to implement the method provided in the first aspect.

According to a seventh aspect of the embodiments of the present disclosure, there is provided a computer-readable storage medium in which a computer program is stored. When the computer program is executed by a processor, the method provided in the first aspect described above is implemented.

According to an eighth aspect of an embodiment of the present disclosure, there is provided a sending end, the sending end includes a processor, a communication interface, a memory, and a communication bus, wherein:

The memory is used to store computer programs;

The processor is configured to execute the program stored on the memory to implement the method provided in the second aspect.

According to a ninth aspect of the embodiments of the present disclosure, there is provided a computer-readable storage medium in which a computer program is stored, and when the computer program is executed by a processor, the method provided in the second aspect described above is implemented.

The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects:

Through the method provided by the embodiment of the present disclosure, the threshold value of the retransmission parameter is adjusted in real time according to the correlation between the RTT duration and the network status. Due to the high correlation between the RTT duration and the network status, the RTT duration is longer under poor network conditions, and the RTT duration is shorter under better network conditions. Therefore, the RTT duration reflects the network status and then passes The method of adjusting the retransmission parameter threshold according to the RTT duration can achieve the purpose of adjusting the retransmission parameter threshold in real time according to the network conditions. When the retransmission parameter reaches the retransmission parameter threshold, it stops sending the retransmission request to the initiator in time. In this way, the total retransmission time can be adjusted in real time according to the network conditions. In the case of poor network conditions, it is easier to shorten the total retransmission time by using the method provided in this embodiment, and avoid using a longer time to wait for lost packets. The flexibility of data transmission is better.

It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present disclosure.

BRIEF DESCRIPTION

The drawings herein are incorporated into and constitute a part of this specification, show embodiments consistent with this disclosure, and are used together with the specification to explain the principles of this disclosure. In the drawings:

Fig. 1 is a schematic flowchart of a method for retransmitting data according to an exemplary embodiment;

Fig. 2 is a schematic flowchart of a method for retransmitting data according to an exemplary embodiment;

Fig. 3 is a schematic structural diagram of an apparatus for retransmitting data according to an exemplary embodiment;

Fig. 4 is a schematic structural diagram of an apparatus for retransmitting data according to an exemplary embodiment;

Fig. 5 is a schematic structural diagram of a computer device according to an exemplary embodiment.

Through the above drawings, a clear embodiment of the present disclosure has been shown, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the concept of the present disclosure in any way, but to explain the concept of the present disclosure to those skilled in the art by referring to specific embodiments.

detailed description

Exemplary embodiments will be described in detail here, examples of which are shown in the drawings. When referring to the drawings below, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Rather, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

An exemplary embodiment of the present disclosure provides a method for retransmitting data. As shown in FIG. 1, the processing flow of the method may include the following steps:

Step S110: When the receiving end detects a packet loss event, it sends a retransmission request for the lost data packet to the sending end.

The receiving end may determine the sequence number of the lost data packet based on the sequence number of the received data packet. The receiving end stores the received data packets in the cache, and sorts the received data packets in the cache.

Whenever the receiving end receives a data packet, it can obtain the sequence number N1 of the data packet. If the sequence number N1 is equal to the sequence number N2 of the expected data packet, the data packet with the sequence number N1 can be directly output to the subsequent data packet processing module for subsequent Processing, such as decoding processing.

If the sequence number N1 is less than the sequence number N2 of the expected data packet, the data packet with the sequence number N1 is a late data packet and can be directly discarded.

If the sequence number N1 is greater than the sequence number N2 of the expected data packet, and the sequence number N1 is less than or equal to the maximum sequence number N3 of the data packets stored in the cache, it can be determined whether there is a data packet with the sequence number N1 in the cache, if it does not exist, the sequence number is The data packets of N1 are inserted into the corresponding positions in the cache in sequence. At the same time, the data packets with the sequence number N1 are retransmission data packets or out-of-sequence data packets. Pass the data packet with sequence number N1.

If the sequence number N1 is greater than the sequence number N2 of the expected data packet, and the sequence number N1 is equal to the maximum sequence number N3+1 of the data packets stored in the cache, it is determined whether there is a data packet with the sequence number N1 in the cache, if it does not exist, the sequence number is N1 The data packets are inserted into the corresponding locations in the cache in order.

If the sequence number N1 is greater than the sequence number N2 of the expected data packet, and the sequence number N1 is greater than the maximum sequence number N3+1 of the data packets stored in the cache, it is determined whether there is a data packet with the sequence number N1 in the cache, if it does not exist, the sequence number is N1 The data packets are inserted into the corresponding positions in the cache in order. At the same time, the data packets with the sequence numbers N3+1 to N1-1 are lost data packets. The heavy packets with the sequence numbers N3+1 to N1-1 can be constructed. Pass the request. After constructing the retransmission request for the lost data packet at the receiving end, you can wait 10 ms to eliminate the out-of-order data packets. After waiting for 10 ms, you can send the retransmission request for the missing data packet to the sending end.

In step S120, the receiving end obtains the RTT duration, and determines the threshold of the retransmission parameter based on the RTT duration.

The receiving end may calculate the RTT duration according to the current network condition and a preset estimation algorithm according to a preset period such as 1s. The value of the RTT duration indicates the expected time required for the retransmission request to return from the receiving end to the sending end and the sending end one round trip. In the case of poor network conditions, the RTT duration is longer, and in the case of better network conditions The RTT duration is shorter, and the specific method for calculating the RTT duration is specified in NPQ. You can use 500ms as the dividing line. If the RTT duration is greater than 500ms, you can consider the network condition to be extremely poor.

The receiving end may calculate the RTT duration according to a preset period, and determine the retransmission parameter threshold based on the RTT duration. Due to the high correlation between the RTT duration and the network status, the RTT duration is longer under poor network conditions, and the RTT duration is shorter under better network conditions. Therefore, the current RTT duration can be used to determine The current network condition determines the retransmission parameter threshold according to the current network condition. In this way, the threshold value of the retransmission parameter can be adjusted according to the current network condition, and the real-time performance is better, avoiding the use of a fixed threshold value of the retransmission parameter, and improving the flexibility of the data transmission process.

The threshold of the retransmission parameter may include a threshold of total retransmission consumption duration and a threshold of the number of retransmissions.

Step S130, when the retransmission time is reached after the retransmission request is sent, if the receiving end does not receive the data packet, the retransmission request for the data packet is sent to the sending end, the RTT duration is updated, and the execution is determined based on the RTT duration. Handling of parameter thresholds.

Among them, the retransmission duration is determined based on the RTT duration. The retransmission duration may be the RTT duration plus a preset error duration such as 10ms. The error duration is used to eliminate errors caused by factors such as thread start-up time and non-corresponding system time.

After the receiving end sends the retransmission request to the sending end, it can be timed. If the retransmission time exceeds the receiving end and the data packet returned by the sending end has not been received, the retransmission request may not be able to arrive smoothly due to network reasons. The sending end, or the data packets sent by the sending end cannot reach the receiving end smoothly. At this time, the retransmission request can be sent again.

In addition to sending the retransmission request again, when the retransmission request reaches the retransmission duration and the receiving end does not receive the data packet, you can obtain the current RTT duration to determine whether the current RTT duration is equal to the previous RTT duration . If the network status changes, the current RTT duration is not equal to the previous RTT duration. If the network status remains unchanged, the current RTT duration is equal to the previous RTT duration. After the RTT duration is updated, if the RTT duration changes, the retransmission parameter threshold also changes accordingly. Therefore, steps S120-S130 can be repeatedly performed to update the RTT duration and re-determine the retransmission parameter threshold until a certain value is met. Conditions so far.

Step S140: When the value of the retransmission parameter reaches the corresponding threshold of the retransmission parameter, if the receiving end does not receive the data packet, it stops sending the retransmission request of the data packet.

In a possible implementation manner, the retransmission parameters may include the total retransmission time or the number of retransmissions, or the retransmission parameters may include the total retransmission time and the number of retransmissions. The threshold of the retransmission parameter corresponding to the total retransmission time is the threshold of the total retransmission time, and the threshold of the retransmission parameter corresponding to the number of retransmissions is the threshold of the number of retransmissions.

When the total retransmission consumption time exceeds the total retransmission consumption time threshold, if the receiving end does not receive the data packet, it may stop repeating steps S120-S130. Or, when the number of retransmissions reaches the threshold of the number of retransmissions, if the receiving end does not receive the data packet, it may stop repeating steps S120-S130. At this time, it can be considered that the retransmission process has failed. Since the real-time data transmission requires high real-time performance of the data transmission, if any lost data packet cannot successfully reach the receiving end within a short time, it will no longer continue to wait for the lost data Packets, directly handle other data packets. If you continue to wait for the lost data packets, such as in the video conference scene, there will be a phenomenon of video live video stuck, and the stuck phenomenon will continue for a period of time, and the video conference scene has high requirements for real-time Therefore, if the receiving end cannot successfully receive any lost data packet within a short time, it can directly give up using the lost data packet to draw the video frame.

In a possible implementation, the threshold of the retransmission parameter is the threshold of the total retransmission time. The method for determining whether the retransmission timed out may include: obtaining the RTT duration, and determining the product of the retransmission duration and the first reference number of retransmissions; The sum of the product and the preset reserved duration is the threshold of the total retransmission consumption duration.

The first reference retransmission number may be a preset fixed reference retransmission number, such as 10 times, or may be a reference retransmission number determined based on a correspondence between a preset RTT duration range and a reference retransmission number.

Under the current network conditions, it is expected that if the receiving end never receives the data packet, it needs to send a retransmission request of the first reference retransmission number to the sending end. After each retransmission request, it needs to wait for the length of the retransmission before receiving The total time the terminal needs to wait is the product of the retransmission time and the first reference retransmission times. Due to the possibility of out-of-order data packets, 10ms can be reserved as the length of time to wait for out-of-order data packets. In addition, considering other circumstances, different time lengths can also be reserved, and all the reserved time lengths are added together as the default Reserve time. Then, the sum of the total duration of the product that the receiving end needs to wait and the preset reserved duration can be determined and used as the threshold of the total retransmission consumption duration. If the lost data packet is the expected data packet, and the receiving end has not received the data packet after exceeding the threshold of the total retransmission time after sending the retransmission request of the lost data packet for the first time, it can be judged that the retransmission timed out, indicating Retransmission processing failed.

Since the network condition generally changes, the threshold of the total retransmission time duration determined through steps S120-S130 also changes, but no matter how the threshold of the total retransmission time duration changes, as long as the retransmission is checked for timeout, the receiving end is determined After the first retransmission request for the lost data packet is sent and the data packet is not received when the current total retransmission time threshold is exceeded, it can be judged that the retransmission timed out and the retransmission processing failed. Since the threshold for the total retransmission time consumption can be changed according to the network conditions, the judgment conditions for judging whether the retransmission timed out can be adjusted in real time according to the network conditions, to avoid poor network conditions and to wait for a long time for lost packets, and improve the flexibility of data transmission .

The receiving end can check whether a retransmission times out every time a data packet is stored in the cache. In order to save processing overhead, it is not necessary to set a timer for the retransmission request separately to count down. The length of the packet with the smallest sequence number in the cache stays in the cache to help determine whether the retransmission timed out, because the packet with the lowest sequence number in the cache is in The length of time spent in the cache is approximately equal to the total time spent on retransmissions. By not setting a timer for the retransmission request separately for countdown, but using the length of the packet with the smallest sequence number in the cache to stay in the cache to assist in determining whether the retransmission has timed out, it can save the amount of calculations for determining whether the retransmission has timed out .

In a possible implementation, if the network condition is poor, the receiving end may not request the sending end to retransmit any lost data packets, because even if the sending end retransmits the lost data packets, the success rate is low and time-consuming Longer, real-time data transmission is extremely poor. Therefore, it can be determined whether the RTT duration is greater than the preset duration threshold, such as 500ms. If the RTT duration is greater than 500ms, the total retransmission consumption duration threshold is directly set to the preset duration, such as 10ms, because the total retransmission consumption duration threshold is shorter , Within the shorter total retransmission duration threshold, all the lost packets cannot be successfully retransmitted, that is, the retransmission of all lost packets will time out, and it can reach the automatic retransmission request to stop sending all the lost packets Effect. If the RTT duration is less than or equal to 500 ms, the product of the RTT duration and the first reference retransmission number is determined, and the sum of the product and the preset reserved duration is determined as the total consumption duration threshold for retransmission. If the receiving end does not receive the data packet after the first time it sends a retransmission request for the lost data packet and exceeds the total retransmission time threshold, the minimum sequence number of the data packet in the cache may be determined as the sequence number of the expected data packet. After the minimum sequence number of the data packet in the cache is determined as the sequence number of the expected data packet, if a data packet smaller than the sequence number of the expected data packet can be received, the received data packet is a late data packet, and it is directly discarded. can.

The following describes a method for determining the first reference retransmission number based on the correspondence between the preset RTT duration range and the reference retransmission number. In a possible implementation, after acquiring the RTT duration, the method provided by the embodiment of the present disclosure may further include: determining the RTT to which the acquired RTT duration belongs based on the correspondence between the preset RTT duration range and the reference retransmission times The number of first reference retransmissions corresponding to the duration range.

In the correspondence, the larger the value of the RTT duration range, the fewer the number of retransmissions. The correspondence between the preset RTT duration range and the reference retransmission times may be a reference retransmission times mapping table, as shown in Table 1:

Table 1

The first reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs can be determined by looking up Table 1. For example, if the current RTT duration is 80 ms, the first reference retransmission times are 4 times. If the receiving end sends 4 retransmission requests to the sending end, the total waiting time is 320 ms.

When designing Table 1, the main consideration is that, first, the larger the value of the RTT duration range, the fewer the number of retransmissions. In this way, when the network is in poor condition, fewer retransmission requests are sent to the sender. Retrieve lost packets by means of retransmission. Secondly, the larger the value of the RTT duration range, the greater the threshold of the total retransmission consumption duration. Lastly, the sum of the total retransmission consumption duration thresholds corresponding to any two RTT duration ranges is less than or equal to the RTT update period, such as 1s.

In addition to stopping the retransmission request of the data packet when the retransmission timed out, the retransmission request of the data packet should also be stopped when the number of retransmissions reaches the threshold of the number of retransmissions. In a possible implementation manner, the threshold of the retransmission parameter is a threshold of the number of retransmissions, and a method for determining whether the number of times of retransmissions reaches the threshold of the number of retransmissions may include: acquiring an RTT duration, and retransmitting based on a preset RTT duration range and reference Correspondence of times, determine the second reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs; based on the comparison result of the second reference retransmission times and the third reference retransmission times determined when the retransmission request was sent last time To determine the threshold of retransmission times.

In the correspondence, the larger the value of the RTT duration range, the fewer the number of retransmissions.

You can still refer to Table 1 to determine the second reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs. For the specific determination method, please refer to the description in the related part above. After determining the second reference retransmission number, the threshold value of the number of retransmission times may be determined based on the comparison result of the second reference retransmission number and the third reference retransmission number determined when the retransmission request was previously sent. The correlation between the size of the reference retransmission times and the network status is also high, so the current network status can also be reflected by the size of the retransmission times. The greater the number of retransmissions, the better the network condition. Conversely, the fewer the retransmissions, the worse the network condition.

If the second reference retransmission number is greater than or equal to the previously determined third reference retransmission number, the second reference retransmission number is determined as the retransmission number threshold. The second reference retransmission times are the currently determined reference retransmission times. If the second reference retransmission times are equal to the previously determined third reference retransmission times, it means that the current network condition remains unchanged and the second reference retransmission times can be changed. Determined as the threshold for the number of retransmissions. If the second reference retransmission number is greater than the previously determined third reference retransmission number, it indicates that the current network condition is getting better, and the second reference retransmission number can be determined as the threshold of the retransmission number. Since the threshold of the number of retransmissions changes from the third reference retransmission number to the second reference retransmission number, the duration that the receiving end can wait for the data packet can be updated to: retransmission consumed time + (current RTT duration + error duration) × ( The second reference number of retransmissions-the current number of retransmissions).

If the second reference retransmission count is less than the third reference retransmission count and the retransmitted count is greater than or equal to the second reference retransmission count, the retransmitted count is determined as the retransmission count threshold. The second reference retransmission count is less than the third reference retransmission count, indicating that the current network condition has deteriorated, and the current retransmission count is greater than or equal to the second reference retransmission count, indicating that the current retransmission request has been retransmitted many times. If the number of retransmissions is sufficient, the threshold for the number of retransmissions can be set to the number of retransmissions, and the length of time that the receiving end can wait for a data packet is set to the length of time spent for retransmission. Since the current number of retransmissions has definitely reached the threshold of the number of retransmissions, the receiving end can automatically stop sending the retransmission request of the data packet to the sending end.

If the second reference retransmission count is less than the third reference retransmission count and the retransmitted count is less than the second reference retransmission count, the second reference retransmission count is determined as the retransmission count threshold. The second reference retransmission count is less than the third reference retransmission count, indicating that the current network condition has deteriorated, and the current retransmission count is less than the second reference retransmission count, indicating that the current retransmission count is insufficient. The terminal retransmits several retransmission requests, and the threshold of the number of retransmissions may be set as the second reference number of retransmissions. Since the threshold of the number of retransmissions changes from the third reference retransmission number to the second reference retransmission number, the duration that the receiving end can wait for the data packet can be updated to: retransmission consumed time + (current RTT duration + error duration) × ( The second reference number of retransmissions-the current number of retransmissions).

In a possible implementation, if the data packet is an important data packet, such as an encoded information data packet, an I frame data packet, a frame start data packet, etc., the number of reference retransmissions in Table 1 may be increased or Keep the same, so that if important data packets are lost, you can transmit several more important data packet retransmission requests to ensure the reliability of data transmission. The RTT duration can be obtained. If the type of the data packet is in the preset type set, the second corresponding to the RTT duration range to which the acquired RTT duration belongs is determined based on the first correspondence between the preset RTT duration range and the reference retransmission times Refer to the number of retransmissions; if the type of the data packet is not within the preset type set, then based on the second correspondence between the preset RTT duration range and the reference retransmission times, determine the number corresponding to the RTT duration range to which the acquired RTT duration belongs 2. Refer to the number of retransmissions.

Wherein, the set of preset types may include encoding information data packet types, I frame data packet types, frame start data packet types, and the like. The number of reference retransmissions corresponding to the same RTT duration in the first correspondence is greater than or equal to the number of reference retransmissions in the second correspondence.

If the lost data packet is not an important data packet, you can refer to Table 1 to query the reference retransmission times corresponding to the RTT duration range to which the current RTT duration belongs. If the lost data packet is an important data packet, you can refer to Table 2 To query the number of reference retransmissions corresponding to the RTT duration range to which the current RTT duration belongs.

Table 2

An exemplary embodiment of the present disclosure provides a method for retransmitting data. As shown in FIG. 2, the processing flow of the method may include the following steps:

Step S210, when the sending end detects that the data packet has been sent and stored in the buffer, the RTT duration is obtained, and based on the RTT duration, the first data storage reference duration is determined.

When the sending end detects that the data packet has been sent, it can store the data packet in the cache, in case the data packet is lost during transmission, and the data packet needs to be retransmitted. However, due to the limited storage space of the cache, all the sent data packets cannot be stored in the cache without time limit. Therefore, the sent data packets need to be cleaned according to certain conditions, but they need to be kept as much as possible and may need to be retransmitted. Data packets to improve the hit rate of retransmission requests. Specifically, the storage duration of the data packet can be adjusted according to the network condition and the mechanism of the retransmission request sent by the receiving end.

The RTT duration can be obtained, and the product of the RTT duration and the target reference retransmission times can be determined as the first data storage reference duration. The target number of reference retransmissions may be a preset fixed number of reference retransmissions, such as 10 times, or a reference retransmission number determined based on a correspondence between a preset RTT duration range and a reference retransmission number. In a possible implementation, after acquiring the RTT duration, the sending end may determine the target reference retransmission corresponding to the RTT duration range to which the acquired RTT duration belongs based on the correspondence between the preset RTT duration range and the number of reference retransmissions frequency.

The correspondence between the preset RTT duration range and the reference retransmission times may be a reference retransmission times mapping table, as shown in Table 3:

table 3

The target reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs can be determined by looking up Table 3. For example, if the current RTT duration is 80 ms, the target reference retransmission times are 4 times, and the first data storage reference duration is 320 ms.

When designing Table 3, the main consideration is that, first, the larger the value of the RTT duration range, the fewer the number of retransmissions. In this way, when the network condition is not good, fewer retransmission requests are sent to the sender. Retrieve lost packets by means of retransmission. Secondly, the larger the value of the RTT duration range, the greater the threshold of the total retransmission consumption duration. Lastly, the sum of the total retransmission consumption duration thresholds corresponding to any two RTT duration ranges is less than or equal to the RTT update period, such as 1s.

Step S220: The sending end determines the data storage duration threshold based on the first data storage reference duration and the second data storage reference duration determined when the previous data packet was stored in the cache.

The sending end can obtain the current RTT duration, determine the first data storage reference duration based on the current RTT duration, and determine the first data storage reference duration based on the first data storage reference duration and the second data storage reference duration determined when the previous data packet was stored in the cache, determine Data storage duration threshold.

In a possible implementation, step S220 may include determining the data storage duration based on the first data storage reference duration, the second data storage reference duration determined when the previous packet was stored in the cache, and the pre-acquired reservation duration Threshold.

The reserved duration can be set according to the situation. The reserved duration can include the out-of-order data packet waiting duration such as 10 ms, and can also include the frame interval duration. The frame interval duration may be determined according to the code rate corresponding to the video frame to which the current data packet belongs. For example, the bit rate corresponding to the video frame to which the current data packet belongs is 25 frames per second, then 25 video frames need to be transmitted in one second, and the frame interval between each video frame is 40 ms. For packets belonging to video frames with a low frame rate, if the frame interval duration is taken into consideration within the data storage duration threshold, the hit rate of the retransmission request can be improved.

In a possible implementation, the step of determining the data storage duration threshold based on the first data storage reference duration, the second data storage reference duration determined when the previous data packet was stored in the cache, and the pre-acquired reservation duration may be Including: calculating the time difference between the time point when the current data packet is stored in the cache and the time point when the previous data packet is stored in the cache; if the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference If the value is less than the second data storage reference duration, the sum of the second data storage reference duration and the pre-obtained reserved duration is determined as the data storage duration threshold; if the first data storage reference duration is less than or equal to the second data storage reference duration , And the time difference is greater than or equal to the second data storage reference duration, determine the duration difference between the first data storage reference duration and the second data storage reference duration, and determine the difference between the duration difference and the preset scale factor Product, determine the sum of the product and the first data storage reference duration, and determine the sum of the sum and the reserved duration as the data storage duration threshold; if the first data storage reference duration is greater than the second data storage reference duration, then The sum of the first data storage reference duration and the reserved duration is determined as the data storage duration threshold.

The first data storage reference duration is the data storage reference duration determined when the current data packet is stored in the cache, and the second data storage reference duration is the data storage duration threshold determined when the previous data packet is stored in the cache. If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is less than the second data storage reference duration, that is, the data storage reference duration is unchanged or shortened, and the previous data packet is stored in the cache If the determined data storage duration is not exhausted, you can still use the data storage duration threshold determined when the previous packet was stored in the cache, and the data storage duration threshold can be maintained as the second data storage reference duration and the pre-acquired reservation The sum of time. In the above manner, when the data storage reference duration becomes shorter, the shortened data storage reference duration may not be temporarily selected as the data storage duration threshold, so that as many data packets in the cache as possible can be retained as much as possible, which can improve retransmission The requested hit rate.

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is greater than or equal to the second data storage reference duration, that is, the data storage reference duration is unchanged or shortened, and the previous data packet is stored in the cache When the data storage duration determined by Zhongshi has been exhausted, the data storage duration determined when the previous packet is stored in the cache needs to be slowly reduced to the first data storage reference duration, and the first data storage reference duration and the second data can be determined Store the duration difference between the reference durations, determine the product of the duration difference and the preset scale factor, determine the sum of the product and the first data storage reference duration, and sum the sum with the reserved duration, Determined as the data storage duration threshold.

If the first data storage reference duration is greater than the second data storage reference duration, that is, the data storage reference duration becomes longer, you can directly set the data storage duration threshold to the maximum data storage reference duration. You can set the first data storage reference duration to The sum of the reserved duration is determined as the threshold of the data storage duration.

Step S230: The sending end deletes the data packets that have been stored in the buffer for a time period that exceeds the data storage duration threshold.

The sending end can determine the current system time, subtract the data storage duration threshold from the current system time to obtain the data expiration time point, and delete all the data packets in the cache before the data expiration time point.

In step S240, the sending end updates the RTT duration, and then proceeds to execute the process of acquiring the RTT duration when it is detected that the data packet has been sent and stored in the buffer.

The RTT duration is updated according to the period, so the RTT duration is not a fixed value, and the RTT duration can be updated each time a data packet is stored in the cache. You can obtain the current RTT duration to determine whether the current RTT duration is equal to the previous RTT duration. If the network status changes, the current RTT duration is not equal to the previous RTT duration. If the network status remains unchanged, the current RTT duration is equal to the previous RTT duration. After the RTT duration is updated, if the RTT duration changes, the first data storage reference duration also changes accordingly, so steps S210-S240 need to be repeated.

According to the method provided by the embodiment of the present disclosure, the storage duration of the data packet is adjusted according to the network condition and the mechanism of the retransmission request sent by the receiving end. In this way, the storage space of the cache can be appropriately saved, and at the same time, the hit rate of the retransmission request can be improved.

Yet another exemplary embodiment of the present disclosure provides an apparatus for retransmitting data. As shown in FIG. 3, the apparatus includes:

The sending module 310 is configured to send a retransmission request for the lost data packet to the sending end when a packet loss event is detected;

The determining module 320 is used to obtain the RTT duration, and determine the threshold of the retransmission parameter based on the RTT duration;

The update module 330 is configured to send a retransmission request of the data packet to the sending end to update the RTT duration when the retransmission duration reaches the retransmission duration after the retransmission request is sent. To execute the process of determining the retransmission parameter threshold based on the RTT duration;

The stopping module 340 is configured to stop sending the retransmission request of the data packet if the value of the retransmission parameter reaches the corresponding threshold value of the retransmission parameter, if the data packet is not received.

Optionally, the threshold of the retransmission parameter is a threshold of total retransmission consumption duration, and the determination module 320 is configured to:

Optionally, the determination module 320 is also used to:

Optionally, the threshold of the retransmission parameter is a threshold of the number of retransmissions, and the determination module 320 is configured to:

Optionally, the determination module 320 is configured to:

Get RTT duration;

Yet another exemplary embodiment of the present disclosure provides an apparatus for retransmitting data. As shown in FIG. 4, the apparatus includes:

The determining module 410 is configured to obtain the RTT duration when it is detected that the data packet has been sent and stored in the cache, and determine the first data storage reference duration based on the RTT duration; based on the first data storage reference duration and the previous data packet The second data storage reference duration determined when stored in the cache, to determine the data storage duration threshold;

The deleting module 420 is configured to delete a data packet that has been stored in the cache for a duration that exceeds the data storage duration threshold;

The update module 430 is used to update the RTT duration and go to the process of acquiring the RTT duration when it is detected that the data packet has been sent and stored in the buffer.

Optionally, the determination module 410 is configured to:

Optionally, the determination module 410 is also used to:

Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment related to the method, and will not be elaborated here.

With the apparatus provided by the embodiment of the present disclosure, the threshold of the retransmission parameter is adjusted in real time according to the correlation between the RTT duration and the network status. Due to the high correlation between the RTT duration and the network status, the RTT duration is longer under poor network conditions, and the RTT duration is shorter under better network conditions. Therefore, the RTT duration reflects the network status and then passes The method of adjusting the retransmission parameter threshold according to the RTT duration can achieve the purpose of adjusting the retransmission parameter threshold in real time according to the network conditions. When the retransmission parameter reaches the retransmission parameter threshold, it stops sending the retransmission request to the initiator in time. In this way, the total retransmission time can be adjusted in real time according to the network conditions. In the case of poor network conditions, it is easier to shorten the total retransmission time by using the device provided in this embodiment, avoiding the use of a longer time to wait for lost data packets. The flexibility of data transmission is better.

It should be noted that the device for retransmitting data provided in the above embodiments only uses the division of the above functional modules as an example for retransmission of data. In practical applications, the above functions can be allocated by different functional modules as needed Completion means dividing the internal structure of the sending end and the receiving end into different functional modules to complete all or part of the functions described above. In addition, the device for retransmitting data provided in the above embodiments and the method embodiment for retransmitting data belong to the same concept. For the specific implementation process, see the method embodiment, and details are not described here.

Yet another exemplary embodiment of the present disclosure provides a system for retransmitting data. The system includes a sending end and a receiving end, where:

The receiving end is used to send a retransmission request of the lost data packet to the sending end when a packet loss event is detected; obtain the RTT duration, determine the retransmission parameter threshold based on the RTT duration; During the transmission time, if the data packet is not received, send a retransmission request of the data packet to the sending end, update the RTT duration, and proceed to perform the process of determining the retransmission parameter threshold based on the RTT duration; When the value of the retransmission parameter reaches the corresponding threshold of the retransmission parameter, if the data packet is not received, stop sending the retransmission request of the data packet;

Regarding the system in the above embodiments, the specific manners in which the sending end and the receiving end perform operations have been described in detail in the embodiments of the method, and will not be elaborated here.

FIG. 5 shows a schematic structural diagram of a computer device 1900 provided by an exemplary embodiment of the present disclosure. The computer device 1900 may be a sending end or a receiving end in the foregoing embodiments, and may have a relatively large difference due to different configurations or performances, and may include one or more processors (central processing units 1910) and one or more The above memory 1920. Wherein, at least one instruction is stored in the memory 1920, and the at least one instruction is loaded and executed by the processor 1910 to implement the method for retransmitting data described in the foregoing embodiment.

Those skilled in the art will easily think of other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptive changes of the present disclosure that follow the general principles of the present disclosure and include common general knowledge or common technical means in the technical field not disclosed in the present disclosure . The description and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are pointed out by the claims.

It should be understood that the present disclosure is not limited to the precise structure that has been described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

A method for retransmitting data, characterized in that the method includes:

When a packet loss event is detected, a retransmission request for the lost data packet is sent to the sender;

Obtain the RTT duration and determine the retransmission parameter threshold based on the RTT duration;

When the retransmission time is reached after the retransmission request is sent, if the data packet is not received, the retransmission request of the data packet is sent to the sending end, the RTT duration is updated, and the execution proceeds to the determination based on the RTT duration Retransmission parameter threshold processing;

When the value of the retransmission parameter reaches the corresponding threshold of the retransmission parameter, if the data packet is not received, stop sending the retransmission request of the data packet.
The method according to claim 1, wherein the retransmission parameters include a total retransmission consumption duration and/or the number of retransmissions, and the threshold of the retransmission parameter corresponding to the total retransmission consumption duration is the total retransmission consumption Duration threshold, the threshold of the retransmission parameter corresponding to the number of retransmissions is the threshold of the number of retransmissions.
The method according to claim 2, wherein the threshold of the retransmission parameter is a threshold of total retransmission duration, and the acquiring RTT duration and determining the threshold of the retransmission parameter based on the RTT duration include:

Obtain the RTT duration, determine the retransmission duration corresponding to the RTT duration, and determine the product of the retransmission duration corresponding to the RTT duration and the first reference number of retransmissions;

The sum of the product and the preset reserved duration is determined as a total consumption duration threshold for retransmission.
The method according to claim 3, wherein after obtaining the RTT duration, the method further comprises:

Based on the correspondence relationship between the preset RTT duration range and the reference retransmission times, determine the first reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs, wherein in the correspondence, the larger the value of the RTT duration range corresponds to The fewer the number of retransmissions.
The method according to claim 2, wherein the threshold of the retransmission parameter is a threshold of the number of retransmissions, and the obtaining the RTT duration, and determining the threshold of the retransmission parameter based on the RTT duration includes:

Obtain the RTT duration, and determine the second reference retransmission number corresponding to the RTT duration range to which the acquired RTT duration belongs based on the correspondence relationship between the preset RTT duration range and the reference retransmission times, wherein, in the correspondence, the RTT duration range The larger the value, the fewer the retransmission times;

Based on the comparison result of the second reference retransmission times and the third reference retransmission times determined when the retransmission request was sent last time, the threshold value of the retransmission times is determined.
The method according to claim 5, wherein the threshold value of the number of retransmissions is determined based on a comparison result of the second reference number of retransmissions and the third reference number of retransmissions determined when the retransmission request was sent last time, include:

If the second reference retransmission number is greater than or equal to the previously determined third reference retransmission number, determine the second reference retransmission number as the retransmission number threshold;

If the second reference retransmission times are less than the third reference retransmission times and the retransmission times are greater than or equal to the second reference retransmission times, the retransmission times are determined as a threshold of retransmission times;

If the second reference retransmission count is less than the third reference retransmission count and the retransmitted count is less than the second reference retransmission count, then the second reference retransmission count is determined as the retransmission count threshold.
The method according to claim 5, wherein the acquiring RTT duration determines the second reference corresponding to the RTT duration range to which the acquired RTT duration belongs based on the correspondence between the preset RTT duration range and the number of reference retransmissions Number of retransmissions, including:

Get RTT duration;

If the type of the data packet is in the preset type set, then based on the first correspondence between the preset RTT duration range and the reference retransmission times, determine the second reference weight corresponding to the RTT duration range to which the acquired RTT duration belongs Transmission times

If the type of the data packet is not in the preset type set, based on the second correspondence between the preset RTT duration range and the reference retransmission times, determine the second corresponding to the RTT duration range to which the acquired RTT duration belongs Reference number of retransmissions, where the number of reference retransmissions corresponding to the same RTT duration range in the first correspondence is greater than or equal to the number of reference retransmissions corresponding to the second correspondence.
A method for retransmitting data, characterized in that the method includes:

When it is detected that the data packet has been sent and stored in the buffer, the RTT duration is obtained, and based on the RTT duration, the first data storage reference duration is determined;

Determine a data storage duration threshold based on the first data storage reference duration and the second data storage reference duration determined when the previous data packet was stored in the cache;

Delete data packets that have been stored in the cache for longer than the data storage duration threshold;

Update the RTT duration and go to the process of acquiring the RTT duration when it is detected that the data packet has been sent and stored in the buffer.
The method according to claim 8, wherein the data storage duration threshold is determined based on the first data storage reference duration and the second data storage reference duration determined when the previous data packet is stored in the cache ,include:

The data storage duration threshold is determined based on the first data storage reference duration, the second data storage reference duration determined when the previous data packet was stored in the cache, and the pre-acquired reservation duration.
The method according to claim 9, wherein the second data storage reference duration determined when the previous data packet is stored in the cache based on the first data storage reference duration and the pre-acquired reservation Duration, determine the data storage duration threshold, including:

Calculating the time difference between the time point when the current data packet is stored in the cache and the time point when the previous data packet is stored in the cache;

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is less than the second data storage reference duration, the second data storage reference duration is obtained in advance The sum of the reserved time is determined as the data storage time threshold;

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is greater than or equal to the second data storage reference duration, it is determined that the first data storage reference duration is equal to A duration difference between the second data storage reference durations, determining a product between the duration difference and a preset scale factor, and determining a sum between the product and the first data storage reference duration , The sum of the sum value and the reserved duration is determined as the data storage duration threshold;

If the first data storage reference duration is greater than the second data storage reference duration, the sum of the first data storage reference duration and the reserved duration is determined as a data storage duration threshold.
The method according to claim 9 or 10, wherein the method further comprises:

The reserved duration is determined based on the frame rate of the video frame to which the data packet belongs.
An apparatus for retransmitting data, characterized in that the apparatus includes:

The sending module is used to send a retransmission request for the lost data packet to the sending end when a packet loss event is detected;

The determining module is used to obtain the RTT duration, and determine the retransmission parameter threshold based on the RTT duration;

The update module is used to send a retransmission request of the data packet to the sending end to update the RTT time when the retransmission time reaches the retransmission time after the retransmission request is sent, and go to Perform the process of determining the threshold of retransmission parameters based on the RTT duration;

The stopping module is configured to stop sending the retransmission request of the data packet if the value of the retransmission parameter reaches the corresponding threshold value of the retransmission parameter, if the data packet is not received.
The apparatus according to claim 12, wherein the retransmission parameters include a total retransmission consumption duration and/or the number of retransmissions, and the threshold of the retransmission parameter corresponding to the total retransmission consumption duration is the total retransmission consumption Duration threshold, the threshold of the retransmission parameter corresponding to the number of retransmissions is the threshold of the number of retransmissions.
The apparatus according to claim 13, wherein the threshold of the retransmission parameter is a threshold of total retransmission duration, and the determination module is configured to:

Obtain the RTT duration, determine the retransmission duration corresponding to the RTT duration, and determine the product of the retransmission duration corresponding to the RTT duration and the first reference number of retransmissions;

The sum of the product and the preset reserved duration is determined as a total consumption duration threshold for retransmission.
The apparatus according to claim 14, wherein the determination module is further used to:

Based on the correspondence relationship between the preset RTT duration range and the reference retransmission times, determine the first reference retransmission times corresponding to the RTT duration range to which the acquired RTT duration belongs, wherein in the correspondence, the larger the value of the RTT duration range corresponds to The fewer the number of retransmissions.
The apparatus according to claim 13, wherein the threshold of the retransmission parameter is a threshold of the number of retransmissions, and the determination module is configured to:

Obtain the RTT duration, and determine the second reference retransmission number corresponding to the RTT duration range to which the acquired RTT duration belongs based on the correspondence relationship between the preset RTT duration range and the reference retransmission times, wherein, in the correspondence, the RTT duration range The larger the value, the fewer the retransmission times;

Based on the comparison result of the second reference retransmission times and the third reference retransmission times determined when the retransmission request was sent last time, the threshold value of the retransmission times is determined.
The apparatus according to claim 16, wherein the determination module is configured to:

If the second reference retransmission number is greater than or equal to the previously determined third reference retransmission number, determine the second reference retransmission number as the retransmission number threshold;

If the second reference retransmission times are less than the third reference retransmission times and the retransmission times are greater than or equal to the second reference retransmission times, the retransmission times are determined as a threshold of retransmission times;

If the second reference retransmission count is less than the third reference retransmission count and the retransmitted count is less than the second reference retransmission count, then the second reference retransmission count is determined as the retransmission count threshold.
The apparatus according to claim 16, wherein the determination module is configured to:

Get RTT duration;

If the type of the data packet is in the preset type set, then based on the first correspondence between the preset RTT duration range and the reference retransmission times, determine the second reference weight corresponding to the RTT duration range to which the acquired RTT duration belongs Transmission times

If the type of the data packet is not in the preset type set, based on the second correspondence between the preset RTT duration range and the reference retransmission times, determine the second corresponding to the RTT duration range to which the acquired RTT duration belongs Reference number of retransmissions, where the number of reference retransmissions corresponding to the same RTT duration range in the first correspondence is greater than or equal to the number of reference retransmissions corresponding to the second correspondence.
An apparatus for retransmitting data, characterized in that the apparatus includes:

The determining module is used to obtain the RTT duration when it is detected that the data packet has been sent and stored in the cache, and determine the first data storage reference duration based on the RTT duration; based on the first data storage reference duration and the previous data packet storage The second data storage reference duration determined when entering the cache, to determine the data storage duration threshold;

A deletion module, configured to delete a data packet that has been stored in the cache for more than the data storage duration threshold;

The update module is used to update the RTT duration and go to the process of acquiring the RTT duration when it is detected that the data packet is sent and stored in the buffer.
The apparatus according to claim 19, wherein the determination module is configured to:

The data storage duration threshold is determined based on the first data storage reference duration, the second data storage reference duration determined when the previous data packet was stored in the cache, and the pre-acquired reservation duration.
The apparatus according to claim 20, wherein the determination module is configured to:

Calculating the time difference between the time point when the current data packet is stored in the cache and the time point when the previous data packet is stored in the cache;

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is less than the second data storage reference duration, the second data storage reference duration is obtained in advance The sum of the reserved time is determined as the data storage time threshold;

If the first data storage reference duration is less than or equal to the second data storage reference duration, and the time difference is greater than or equal to the second data storage reference duration, it is determined that the first data storage reference duration is equal to A duration difference between the second data storage reference durations, determining a product between the duration difference and a preset scale factor, and determining a sum between the product and the first data storage reference duration , The sum of the sum and the reserved duration is determined as a threshold of the data storage duration;

If the first data storage reference duration is greater than the second data storage reference duration, the sum of the first data storage reference duration and the reserved duration is determined as a data storage duration threshold.
The apparatus according to claim 20 or 21, wherein the determination module is further used to:

The reserved duration is determined based on the frame rate of the video frame to which the data packet belongs.
A system for retransmitting data, characterized in that the system includes a sending end and a receiving end, wherein:

The receiving end is used to send a retransmission request for a lost data packet to the sending end when a packet loss event is detected; obtain the RTT duration, and determine the retransmission parameter threshold based on the RTT duration; after sending the retransmission request When the retransmission duration is reached, if the data packet is not received, a retransmission request for the data packet is sent to the sending end, the RTT duration is updated, and the process of determining the retransmission parameter threshold based on the RTT duration is performed ; When the value of the retransmission parameter reaches the corresponding threshold of the retransmission parameter, if the data packet is not received, stop sending the retransmission request of the data packet;

The sending end is used to obtain the RTT duration when it is detected that the data packet has been sent and stored in the cache, and determine the first data storage reference duration based on the RTT duration; based on the first data storage reference duration and the previous data The second data storage reference duration determined when the packet is stored in the cache to determine the data storage duration threshold; deleting the data packets that have been stored in the cache for longer than the data storage duration threshold; updating the RTT duration , Go to the process of acquiring the RTT duration when it is detected that the data packet has been sent and stored in the buffer.
A receiving end, characterized in that the receiving end includes a processor, a communication interface, a memory, and a communication bus, wherein:

The processor, the communication interface, and the memory complete communication with each other through the communication bus;

The memory is used to store computer programs;

The processor is configured to execute the program stored on the memory to implement the method steps of any one of claims 1-7.
A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the method steps of any one of claims 1-7 are realized.
A sending end, characterized in that the sending end includes a processor, a communication interface, a memory, and a communication bus, wherein:

The processor, the communication interface, and the memory complete communication with each other through the communication bus;

The memory is used to store computer programs;

The processor is configured to execute the program stored on the memory to implement the method steps of any one of claims 8-11.
A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the method steps of any one of claims 8-11 are realized.