WO2011144141A1

WO2011144141A1 - Method, system and network device for congestion control

Info

Publication number: WO2011144141A1
Application number: PCT/CN2011/075163
Authority: WO
Inventors: 崔翔嵩
Original assignee: 华为技术有限公司
Priority date: 2010-09-13
Filing date: 2011-06-02
Publication date: 2011-11-24
Also published as: CN102404187A

Abstract

The embodiments of the present invention provide a method, system and network device for congestion control. The method for congestion control comprises the following steps: obtaining the network bandwidth information of the data transmission path between a transmission end device and a reception end device; adjusting a data transmission rate according to the network bandwidth information; transmitting packet data to the reception end device on the basis of the adjusted data transmission rate. In the embodiments of the present invention, the transmission end device performs adjustment on the data transmission rate with higher accuracy and without wide fluctuation. Further more, not only can the packet data be transmitted on a non congestion data transmission path, but also the network performance can be exhibited sufficiently, and thereby the waste of network resources is avoided.

Description

Congestion control method and system and network device

The present application claims priority to Chinese Patent Application No. 201010281210.4, entitled "Congestion Control Method and System and Network Equipment", filed on September 13, 2010, the entire contents of in. Technical field

The embodiments of the present invention relate to communication technologies, and in particular, to a congestion control method and system, and a network device. Background technique

The Transmission Control Protocol (TCP) is a commonly used transport layer protocol and can be used for reliable data transmission between nodes in a packet network. Congestion control is an important control function for TCP to ensure reliable transmission of data in a packet network. Congestion control refers to the control of sending data to the network to avoid congestion caused by excessive data and beyond the limits that the intermediate network can withstand.

The sender device adjusts the size of the transmission window according to the number of received ACK messages, thereby adjusting the data transmission rate, thereby implementing congestion control. The receiving end device receives the packet data and returns the ACK message, which is affected by many network factors. Therefore, the sending end device calculates the sending window size according to the number of received ACK messages, and performs congestion control according to the size of the sending window, thereby causing low control precision. . Summary of the invention

The embodiments of the present invention provide a congestion control method and system, and a network device, to solve the problem that the control precision of the transmitting device is low when performing congestion control.

In one aspect, a congestion control method is provided, including:

Obtaining network bandwidth information of a data transmission path between the sender device and the sink device; And adjusting the data transmission rate according to the network bandwidth information; and sending the packet data to the receiving end device according to the adjusted data transmission rate. In one aspect, a network device is provided, including:

An acquiring module, configured to acquire network bandwidth information of a data transmission path between the sender device and the receiver device;

a processing module, configured to perform an adjustment process on the data sending rate according to the network bandwidth information acquired by the acquiring module;

And a sending module, configured to send, according to the processing module, the processed data transmission rate, to send the packet data to the receiving end device.

In one aspect, a congestion control system is provided, including: a sender device and a receiver device, where the sender device is configured to acquire a network bandwidth of a data transmission path between the sender device and the receiver device. And adjusting the data transmission rate according to the network bandwidth information; and sending the packet data to the receiving end device according to the adjusted data transmission rate;

The receiving end device is configured to receive packet data sent by the sending end device.

In the congestion control method provided by the embodiment of the present invention, the transmitting end device adjusts the data transmission rate by using the network bandwidth information, so that the data sending rate changes around the network bandwidth information, and therefore, the sending end device adjusts the data sending rate. The precision is high so that there is no large fluctuation in the sliding window mechanism. Moreover, the data transmission rate of the packet data sent by the sender device is matched with the capability of the data transmission path, so that the packet data can be transmitted on the uncongested data transmission path, and the network performance can be fully utilized to avoid waste of network resources. . DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description of the drawings used in the embodiments or the prior art description will be briefly described below. The drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive labor.

1 is a flowchart of Embodiment 1 of a congestion control method according to the present invention;

2 is a flowchart of Embodiment 2 of a congestion control method according to the present invention;

3 is a flowchart of Embodiment 3 of a congestion control method according to the present invention;

4 is a flowchart of Embodiment 4 of a congestion control method according to the present invention;

5 is a flowchart of Embodiment 5 of a congestion control method according to the present invention;

6 is a schematic structural diagram of an embodiment of a network device according to the present invention;

Figure Ί is a schematic structural view of Embodiment 1 of the congestion control system of the present invention;

FIG. 8 is a schematic structural diagram of Embodiment 2 of a congestion control system according to the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

1 is a flowchart of Embodiment 1 of a congestion control method according to the present invention. As shown in FIG. 1, the method in this embodiment may include:

Step 101: Obtain network bandwidth information of a data transmission path between the source device and the receiver device.

Packet networks have two capabilities: packet data forwarding capabilities and packet data caching capabilities. There is no direct connection between these two capabilities. As a packet storage and forwarding device, the router has a strong queue storage function. That is to say, the packet data sent by the sending device to the receiving device can be cached in the router and then forwarded to the receiving device. Therefore, For this part of the buffered packet data, the time when the ACK message is fed back to the sender device will be Delay. Or, the data transmission path, under the influence of many other network factors, discards the ACK message fed back to the sender device, causing the sender device to mistakenly believe that the network data is congested, resulting in packet data transmission failure. Therefore, if the prior art is used, since the delayed ACK message is not received within a certain period of time, the transmitting device will consider that congestion occurs, and then reduce the size of the transmission window, and subsequently receive these delayed ACK messages. At the same time, the transmitting device will consider the congestion state to be eliminated, and then increase the size of the sending window. Therefore, the congestion control method of the prior art is likely to cause a large fluctuation in the size of the transmission window, and the network forwarding capability cannot be fully utilized effectively. Moreover, the transmitting device cannot confirm whether the packet data is transmitted in the adjusted transmission window, and congestion occurs. When the transmission window is increased beyond the actual packet forwarding capability of the network, the excess packet data will be discarded by the network, resulting in waste of network resources.

For the above-mentioned prior art, the size of the transmission window of the transmitting device, that is, the problem of adjusting the data transmission rate, in this embodiment, the transmitting device can adjust the packet according to the current network environment. The data transmission rate of the data to avoid congestion.

Specifically, the sender device can obtain network bandwidth information of a data transmission path between the sender device and the receiver device.

The embodiment does not limit the manner in which the source device obtains the network bandwidth information. For example, the network bandwidth information is not included in the message, and the network device obtains the network bandwidth information from the network entity. For example, the network bandwidth information is not limited to be sent by the receiving device, and may be sent to any network entity in the network that has network bandwidth monitoring or network bandwidth management functions. Moreover, a person skilled in the art can adjust the monitoring or management period of the network bandwidth information as needed, or adjust the bandwidth management monitoring mode to event triggering, so that the sending end device can flexibly provide according to the network bandwidth monitoring or the network bandwidth management unit. The network bandwidth information adjusts the data transmission rate.

Step 102: Perform adjustment processing on a data transmission rate according to the network bandwidth information. After obtaining the network bandwidth information, the sending device can learn the current network environment. Ben Those skilled in the art can understand that the network bandwidth information is not limited to the network bandwidth itself, but represents any parameter that can reflect the network bandwidth information.

Specifically, if the network environment reflected by the network bandwidth information is better, the transmitting device can increase the data sending rate correspondingly, and the network bandwidth reflected by the network bandwidth information is poor. For example, when congestion has occurred, The sender device can reduce the data transmission rate accordingly. Therefore, in this embodiment, the network bandwidth information can be used as a reference standard for adjusting the data transmission rate, so that the data transmission rate changes around the network bandwidth information. Therefore, the accuracy of the data transmission rate adjustment by the transmitting device is higher. High, without the large fluctuations of the sliding window mechanism.

It should be noted that the operation of adjusting the data transmission rate may be performed by the sender device directly adjusting the data transmission rate according to the network bandwidth information, or may be expressed by the sender device according to the network bandwidth information. Adjust the size of the send window. In addition, the data transmission rate may be the number of data packets transmitted per unit time or the number of data bits transmitted per unit time.

Step 103: Send packet data to the receiving end device according to the data transmission rate after the adjustment processing.

Since the network bandwidth information can objectively reflect the network environment, and does not depend on the number of ACK messages received by the sending end device and the size of the sending window, the sending end device sends the packet data at the adjusted data sending rate. The capabilities of the data transmission path are matched, so that the packet data can be transmitted on the uncongested data transmission path, and the network performance can be fully utilized to avoid waste of network resources.

In the congestion control method of the embodiment, the source device adjusts the data transmission rate by using the network bandwidth information, so that the data transmission rate changes around the network bandwidth information, so the sender device adjusts the data transmission rate. The accuracy is high without significant fluctuations. Moreover, the sending end device transmits the packet data at the adjusted data transmission rate to match the capability of the data transmission path, thereby enabling the packet data to be transmitted without congestion. Transmission on the transmission path can fully utilize the network performance and avoid waste of network resources.

The technical solutions of the present invention will be described in detail below using three specific embodiments.

2 is a flowchart of Embodiment 2 of the congestion control method of the present invention. As shown in FIG. 2, in the method of this embodiment, the network bandwidth information is obtained by the device at the sending end. The method in this embodiment may include:

Step 201: The sending end device establishes a TCP connection with the receiving end device.

The initiator of establishing a TCP connection can be either a sender device or a sink device. Step 202: The sending device initializes a congestion control parameter.

After the sender device establishes a TCP connection with the receiver device, the sender device can initialize congestion control parameters, such as the number of packets that can be sent before receiving the acknowledgment message, the bandwidth/rate calculation period 1, the data transmission rate, and the increase of the path bandwidth. The measurement factor, the decrement factor _{q of the} data transmission rate and the path bandwidth when congestion occurs, and at least one of the number K of repeated acknowledgment messages triggering the fast retransmission.

Step 203: The sending end device sends the first packet data packet to the receiving end device, and records the sending time Γ0, and then continues to send other packet data packets until the N packet data packets are completely sent.

Step 204: The sending end device receives the first acknowledgement message sent by the receiving end device, records the receiving time 71, and calculates an initial data sending rate Rate.

After receiving the first packet data packet sent by the sending end device, the receiving end device may send an ACK message to the sending end device, where the ACK message includes a byte sequence number of the expected next packet data packet, the byte The sequence number can be used to indicate the packet data byte that has been received. For example, the expected byte sequence number of the next packet data packet is X, which means that the byte sequence number is the packet data byte before X-1. All have been received continuously, so that the sender device packet data byte can be successfully received.

After receiving the first ACK message, the sending device can record the receiving time Γ1 of the ACK message and enter the rate controlled phase.

In this embodiment, it can be assumed that during the period from TO to 71, the transmitting device sends a total of N Packet data packet, therefore, this embodiment can calculate the initial data transmission rate Rate by applying formula (4).

N ■

8 ^x packet _ size _i

Rate = ~ ^ ( 4 )

71 - 70 where 4 packet — s represents the sum of the number of bits of the N packet data packets initially transmitted. It should be noted that formula (4) is used for the first time that the transmitting device calculates the sending rate of the packet data packet. In a more general case, the rate calculation can use the formula (3).

y

8 ^x packet _ size _i

Rate = -

Ty - Tx

(3)

Wherein, Rate represents the data transmission rate during the transmission of the packet data packets X to y by the transmitting device, Ty represents the time at which the packet data packet y is transmitted, and Tx represents the time at which the packet data packet X is transmitted.

8 ^χ packet _ size _i represents the sum of the total number of bits transmitted by the transmitting device during the transmission of the packet data X ~ y.

Step 205: The sending end device receives multiple ACK messages sent by the receiving end device, and calculates and obtains network bandwidth information according to the received ACK message.

Specifically, the sending end device may calculate and obtain network bandwidth information according to the received acknowledgment information included in the at least two ACK messages sent by the receiving end device and the receiving time of the acknowledgment message. The acknowledgement information is sent by the receiving end device to the sending end device in an ACK message.

After receiving the packet data packet sent by the sending end device, the receiving end device may send an ACK message to the sending end device, indicating that the packet data packet sent by the sending end device is successfully received, and the acknowledgement information included in the ACK message may be expected. The byte sequence number of the next packet packet may also contain a selective acknowledgment parameter. The selective confirmation parameter is used to indicate the sending end device, and the receiving end device receives the packet data packet that is not continuously received in sequence. For example, the receiving end device indicates that the byte sequence number of the next packet data packet expected by the transmitting end device is XI. At the same time The selective acknowledgement parameter indicates that the packet data byte with sequence number X2 ~ X3 has been received, which means that the receiving device waits to receive the packet data packet with the byte sequence number XI - X2-1 and the byte sequence number greater than X3. . After receiving each ACK message, the transmitting device records the receiving time of the ACK message, for example, time T2, Τ3, Τ4, and confirms the amount of data that has been successfully received by the receiving device according to the received ACK message and the received data. The receiving time of the previous ACK message and the last ACK message is calculated to obtain network bandwidth information. In this process, the sending device may select two acknowledgment messages as needed, or select the first acknowledgment message and the last acknowledgment message in the period according to the bandwidth measurement period, and the bandwidth calculation period has passed after establishing the TCP connection in step 201. The parameter initialization in step 202 is given. It can be understood by those skilled in the art that by adjusting the bandwidth calculation period, the update frequency of the packet transmission rate can be adjusted.

For example, in this embodiment, the network bandwidth information can be calculated by using the formula (1), π _J . _{Λ Λ} 8x [(Seq2 - Seql) + (SACK2 block - SACK1 block)], ₁

Bandwidth —————— ― ~ = = — I (丄 )

T ACK2 - T ACK1 ^J where Bandwidth is the network bandwidth, Seq2 is the consecutive acknowledgment sequence number of the next ACK message, Seql is the consecutive acknowledgment sequence number of the previous ACK message, and SACK2_block is the word of the selective acknowledgment parameter in the latter ACK message. The number of sections, SACKl_block is the number of bytes of the selective acknowledgment parameter in the previous ACK message, T_ACK2 is the reception time of the latter ACK message, and T_ACK1 is the reception time of the previous ACK message.

It should be noted that the sender device can only use the continuous acknowledgment message or the ACK message with the selective acknowledgment parameter for bandwidth calculation, and cannot use the duplicate acknowledgment message for bandwidth calculation.

It should be specially noted that Seql and Seq2 are the sequence numbers of the packet data packets, because the packet sequence number is used for cyclic scrolling. For example, the cycle number of the sequence number is 0 ~ 65535, then the next sequence number of 65535 is 0. For the case of Seql<Seq2, use the formula (1) to calculate

When Seql>Seq2, the formula (1) can be further adjusted to the formula (2):

Bandwidth - ^{8 x} [( ² - ^Se ^ + Q ^c/g ) + (SACK2_block - SACKl block)] ₍₂ a ^{n W1} _ T ACK2 - T ACKl

Cycle is the sequence number cycle. It should be noted that when the ACK message has a timestamp option parameter, T_ACK1 and T ACK2 can be replaced by the value of the timestamp in the respective ACK message. The timestamp option parameter in the ACK message refers to the time information of the ACK message sent by the receiving device in the message when the ACK message is sent by the receiving device, and the transmitting device uses the time information to calculate the bandwidth parameter relative to the time. The calculated reception time calculates the bandwidth parameter, and the calculation accuracy is high.

Steps 202 to 205 above complete the process of the network device acquiring the network bandwidth information.

Step 206: Perform adjustment processing on the data transmission rate according to the network bandwidth information. The adjustment processing may adopt a periodic processing manner, for example, periodically measuring a transmission rate of packet data, acquiring network bandwidth information, and adjusting a data transmission rate according to network bandwidth information during data transmission.

Specifically, if the normal acknowledgment message is received, that is, the acknowledgment message is not repeated, the sending end device adjusts the data sending rate to be greater than the rate of the network bandwidth information; if the repeated acknowledgment message is received or continuously received within the data sending rate adjusting period After multiple repeated acknowledgement messages, the sender device adjusts the data transmission rate to a rate less than the network bandwidth, and after receiving the normal acknowledgement message, calculates new network bandwidth information, and re-adjusts the network bandwidth information according to the new network bandwidth information. Data transmission rate; if no acknowledgment message is received within the data transmission rate adjustment period, the transmitting device adjusts the data transmission rate to a rate less than the network bandwidth or maintains a rate equal to the known network bandwidth, and re-receives After the confirmation message, the new network bandwidth information is calculated, and the data transmission rate is adjusted according to the new network bandwidth information.

For example, the sender device can increase the data transmission rate by using the increment factor p set during parameter initialization, such as Rate = Bandwidth + , or Rate = Bandwidth χ ( 1+ρ ). When the transmitting device receives a plurality of repeated acknowledgment messages set, for example, when the parameter is initialized, it is necessary to immediately resend the missing packet data, and immediately reduce the data transmission rate Rate of the transmitted packet data, for example, using parameter initialization. The set reduction factor q is used to reduce the data transmission rate, such as Rate = Bandwidth - q, or Rate = Bandwidth xq, etc. After the sending end device receives the new ACK message, the sending end device can recalculate the network bandwidth information, and adjust the data sending rate of the packet data packet according to the new network bandwidth information. When the timeout is not confirmed after data transmission occurs, the sender device needs to immediately resend the packet data with timeout unacknowledged, and immediately reduce the rate of sending the packet Rate, for example, Rate = Bandwidth-q, and wait until the sender device receives the new packet. After the ACK message, the source device can recalculate the network bandwidth information and adjust the data transmission rate of the packet data according to the new network bandwidth information.

Alternatively, the sending end device may also use the ratio of the average size of the sent packet data packet to the network bandwidth as the data sending rate, and the ratio is used as the number of packet data packets sent per second, and controls the sending end device to send the packet data packet. s speed.

Step 207: Send packet data to the receiving end device according to the data transmission rate after the adjustment processing.

It should be noted that, in the process of the entire TCP session, the foregoing step 206 and step 207 are repeated, and the sending device records the time of all the data packets being sent. If the data transmission rate is calculated periodically, as long as the rate calculation period arrives, the transmitting device calculates the data transmission rate according to the packet data and the cycle time transmitted in the rate calculation period. If the network bandwidth is calculated periodically, the transmitting device calculates the network bandwidth information as soon as the bandwidth calculation period arrives, and adjusts the data transmission rate in the data transmission rate adjustment period according to the newly calculated network bandwidth information.

Preferably, the bandwidth calculation period and the data transmission rate calculation period used by the transmitting device can be set to be the same or close, so that the adjusted data transmission rate is as close as possible to the current network environment, thereby improving the adjustment precision.

In the congestion control method of the embodiment, the sender device can calculate the network bandwidth information according to the ACK message received in the bandwidth calculation period, so that the data transmission rate can be adjusted by using the network bandwidth information, so that the data transmission rate is around the network bandwidth. The information changes and changes. Therefore, the accuracy of the data transmission rate adjustment by the transmitting device is high, and there is no significant Degree of fluctuations. Moreover, the transmitting end device transmits the packet data at the adjusted data transmission rate to match the capability of the data transmission path, so that the packet data can be transmitted on the uncongested data transmission path, and the network performance can be fully utilized to avoid Waste of network resources.

In addition, in the method of this embodiment, no modification to the receiving end device is required, as long as the receiving end device supports the basic TCP protocol function, and has good generality and compatibility.

3 is a flowchart of Embodiment 3 of a congestion control method according to the present invention. As shown in FIG. 3, in the method of this embodiment, network bandwidth information is calculated by a receiving device and sent to a transmitting device, and the method in this embodiment is used. Can include:

Step 301: The sending end device sends a synchronization/start message (SYN) to the receiving end device, where the synchronization/start message includes a bandwidth parameter indication, where the bandwidth parameter indication is used to indicate that the requesting end device includes network bandwidth information in the ACK message.

The sender device may include a bandwidth parameter indication in the establishment of the connection connection of the TCP connection, for example, the SYN message, the bandwidth parameter indication may indicate the receiving device, and the sending device supports the network bandwidth information in the ACK message, and the The device uses network bandwidth information in this TCP session. Optionally, the SYN message may also include a bandwidth/rate calculation period recommended by the source device.

It should be noted that, in this embodiment, only the sending end device initiates the establishment of a TCP connection to the receiving end. It can be understood by those skilled in the art that the originating TCP connection may also be the receiving end device.

Step 302: The receiving end device sends a synchronization/confirmation message (SYN/ACK) to the sending end device, where the synchronization/confirmation message includes a bandwidth parameter indication.

After the receiving end device receives the synchronization/start message with the bandwidth parameter indication, if the receiving end device also supports the bandwidth parameter in the ACK message, and is willing to use the network bandwidth information in the current TCP session with the transmitting device, then The receiving end device may also include a bandwidth parameter indication in the SYN/ACK message fed back to the transmitting device. Optionally, the S YN/ACK message is also It can include the bandwidth/rate calculation period that the receiving device can support.

Step 303: The sending end device sends an ACK message to the receiving end device, where the ACK message includes a bandwidth parameter indication.

Optionally, the ACK message may also include a bandwidth/rate calculation period negotiated between the sender device and the sink device.

At this point, the TCP connection between the sender device and the sink device is established, and the sender device and the receiver device agree to include network bandwidth information in the ACK message.

Step 304: The sender device initializes a congestion control parameter.

The implementation process is similar to the foregoing step 202, and details are not described herein again.

Step 305: The sending end device sends a packet data packet to the receiving end device.

Optionally, after sending each packet data packet, the sender device can record the sending time of each packet data packet.

Step 306: After receiving the packet data packet sent by the sending end device, the receiving end device records the receiving time of each packet data packet, and sends an ACK message to the sending end device, where the ACK message includes network bandwidth information.

After receiving the packet data packet sent by the sending end device, the receiving end device may send an ACK message to the sending end device, indicating that the packet data packet sent by the sending end device is successfully received, and the ACK message may include the expected next packet. The byte order number of the packet may also contain a selective acknowledgment parameter. The selective confirmation parameter is used to indicate the sending end device, and the receiving end device receives the packet data packet that is not continuously received in sequence. For example, the receiving end device indicates that the byte sequence number of the next packet data packet expected by the transmitting end device is XI. At the same time, the selective acknowledgement parameter indicates that the packet data byte with the sequence number is X2 ~ X3 has been received, which means that the receiving device waits to receive the packet data with the byte sequence number XI - X2-1 and the byte sequence number greater than X3. package.

After receiving the two or more packet data packets, the receiving device may obtain network bandwidth information by calculating the data amount of the average received packet data in a unit time, for example, according to The sum of the data amounts of all the packet data packets received in a certain period of time, and the receiving time of the first packet data packet received during the time period and the receiving time of the last packet data packet, and calculating the network bandwidth information, specifically The calculation method may be the sum of the data amounts of all the data packets in a certain period of time divided by the duration of the time period.

After receiving the first ACK message, the sending end device may calculate the initial data sending rate Rate according to formula (4), and calculate the data sending rate Rate according to the formula (3) period in the subsequent data sending process, and the implementation principle thereof. Similar, it will not be described here.

Step 307: After receiving the ACK message including the network bandwidth information, the sending device may adjust the data sending rate according to the network bandwidth information.

The adjustment processing can be implemented by using the specific implementation manner described in the foregoing step 206, and details are not described herein again.

Step 308: The sending end device sends a packet data packet to the receiving end device according to the data sending rate after the adjustment processing.

It should be noted that, in the process of the entire TCP session, the foregoing steps 306 to 308 are repeated. As soon as the bandwidth calculation period arrives, the receiving device can calculate the network bandwidth information, and calculate the acquired network bandwidth information. The device sends the data to the sending device, so that the sending device can adjust the data sending rate in the data sending rate adjustment period according to the newly calculated network bandwidth information.

Preferably, the bandwidth calculation period and the data transmission rate adjustment period used by the transmitting device can be set to be the same or close, so that the adjusted data transmission rate is as close as possible to the current network environment, thereby improving the adjustment precision.

In the congestion control method of this embodiment, the receiving end device may calculate the difference between the number of packet data packets received during the period and the reception time of the first packet data packet in the bandwidth calculation period and the reception time of the last packet data packet. The value, the network bandwidth information is calculated, and the calculated network bandwidth information is sent to the sending device by using an acknowledgement message, so that the sending device can adjust the data sending rate according to the network bandwidth information, so that the data sending rate is around the network. The bandwidth information changes due to changes in the bandwidth information. Therefore, the accuracy of the data transmission rate adjustment by the transmitting device is high without significant fluctuations. Moreover, the network bandwidth information calculated by the embodiment is more accurate than the technical solution of the second embodiment of the congestion control method. In addition, the sending end device transmits the packet data packet at the adjusted data transmission rate to match the capability of the data transmission path, so that the packet data packet can be transmitted on the uncongested data transmission path, and the network performance can be fully utilized. , to avoid wasting network resources.

4 is a flowchart of Embodiment 4 of a congestion control method according to the present invention. As shown in FIG. 4, in the method of this embodiment, a sender device may obtain network bandwidth information from a network function entity having a bandwidth measurement or bandwidth management function. The method of an embodiment may include:

Step 401: The sending end device establishes a TCP session with the receiving end device.

Step 402: The source device acquires network bandwidth information from a network function entity having a bandwidth measurement or bandwidth management function.

Specifically, the manner in which the sending end device obtains the network bandwidth information may be that the sending end device directly sends a query request to the network function entity, and receives a response message that is sent by the network function entity and carries the network bandwidth information, or may be a network function entity actively The sender device sends network bandwidth information. The above two methods can be used to query/response and indicate transactions periodically, or event-triggered query/response and indication transactions. For example, the sending device queries the network bandwidth information after successfully establishing a TCP session, and the sending device receives the information. After the acknowledgment message is repeated, the network bandwidth information is queried, the network bandwidth information is queried when the sending device fails to confirm the timeout, or the network function entity detects the network bandwidth information and sends the network bandwidth information to the sending device immediately.

It should be specially noted that the network function entity with bandwidth measurement or bandwidth management function can be either on the sender device or on other devices. If the network function entity is on other devices, the sender device can Establish a network connection with the device.

For example, the network function entity may be a channel management unit of an Asynchronous Transfer Mode (ATM), which may obtain a configured bandwidth of an ATM channel, or may be a wireless network control unit of a radio access network. It can get empty The bandwidth capability of the medium interface radio bearer, or may be a resource management unit of the router, which can obtain the packet forwarding capability allocated for the specified interface.

It should be noted that, when the sending end device continuously receives multiple duplicate acknowledgment messages to reach the threshold, for example, if the number exceeds K, the sending end device may immediately retransmit the missing packet data packet, and immediately query the network function entity for the network bandwidth information; When there is a packet data packet timeout and no ACK message is received, the missing packet data packet can also be retransmitted immediately, and the network function entity is immediately queried for network bandwidth information.

Step 403: Perform adjustment processing on the data sending rate according to the network bandwidth information.

Step 404: Send packet data to the receiving end device according to the data transmission rate after the adjustment processing.

Step 403 and step 404 can be repeatedly executed in the TCP session, and the implementation methods of the steps 403 and 404 are similar to the implementation methods of the first embodiment to the third embodiment of the congestion control method, and are not described herein again.

In the congestion control method of the embodiment, the sender device can obtain the network bandwidth information from a network function entity having a bandwidth measurement or bandwidth management function, thereby eliminating the burden of calculating the network bandwidth information by the sender device or the receiver device itself. And can obtain more accurate network bandwidth information, the sending device can directly use the network function entity to monitor the acquired network bandwidth information to adjust the data transmission rate, so that the data sending rate changes around the network bandwidth information, therefore, The transmitting device adjusts the data transmission rate with high precision without significant fluctuations. Moreover, the transmitting end device transmits the packet data at the adjusted data transmission rate to match the capability of the data transmission path, so that the packet data can be transmitted on the uncongested data transmission path, and the network performance can be fully utilized to avoid Waste of network resources. In addition, the network function entity can be maintained separately without changing the sender device and the sink device.

5 is a flowchart of Embodiment 5 of a congestion control method according to the present invention. As shown in FIG. 5, in this embodiment, a receiving end device may be a network functional entity having bandwidth measurement or bandwidth management functions. Obtaining the network bandwidth information, and then sending the network bandwidth information to the sending device, the method in this embodiment may include:

Step 501: The sending end device establishes a TCP session with the receiving end device.

Step 502: The receiving end device acquires network bandwidth information from a network function entity having a network bandwidth measurement function or a network bandwidth management function.

Specifically, the manner in which the receiving end device obtains the network bandwidth information may be that the receiving end device directly sends a query request to the network function entity having the network bandwidth measurement function or the network bandwidth management function, and receives the network bandwidth information sent by the network function entity. The response message may also be that the network function entity having the network bandwidth measurement function or the network bandwidth management function actively sends the network bandwidth information to the receiving end device. The above two methods can be used for query/response and indication transactions periodically, or event-triggered query/response and indication transactions. For example, the receiving device queries the network bandwidth information after successfully establishing a TCP session, and the receiving device is in the direction. The network function entity that queries the network bandwidth information or has the network bandwidth measurement function or the network bandwidth management function after transmitting the duplicate acknowledgement message sends the network bandwidth information to the receiving end device immediately after the network bandwidth changes.

It should be specially noted that the network function entity having the network bandwidth measurement function or the network bandwidth management function may be on the receiving end device or on other devices, if the network functional entity is on other devices, The receiving device can establish a network connection with the device.

For example, the network function entity may be an ATM channel management unit, which may obtain the configured bandwidth of the ATM channel, or may be a radio network control unit of the radio access network, which may obtain the bandwidth capability of the air interface radio bearer allocation. Or it may be a resource management unit of the router, which can obtain the packet forwarding capability assigned to the specified interface.

Step 503: The receiving end device sends the network bandwidth information to the sending end device.

The receiving end device may send network bandwidth information to the sending end device through an ACK message, or may send network bandwidth information to the sending end device by using a new session message. Sending terminal After receiving the message containing the network bandwidth information, if the sending device does not support the method of adjusting the data sending rate according to the network bandwidth information, the message may be discarded. If the sending device supports, the network bandwidth may be received according to the received network bandwidth. The information adjusts the data transmission rate of the packet data packet.

Step 504: The sending end device adjusts the data sending rate according to the network bandwidth information.

Step 505: Send packet data to the receiving end device according to the data transmission rate after the adjustment processing.

Steps 502 to 505 can be repeatedly executed in the TCP session, and the implementation methods of the steps 504 and 505 are similar to the implementation methods of the first embodiment to the third embodiment of the congestion control method, and are not described herein again.

In the congestion control method of the embodiment, the receiving end device may acquire the network bandwidth information from a network function entity having a network bandwidth measurement function or a network bandwidth management function, and send the network bandwidth information to the sending end device, thereby eliminating The sender device or the receiver device itself calculates the burden of network bandwidth, and can obtain more accurate network bandwidth information. The transmitting device can directly adjust the data sending rate by using the network bandwidth information acquired from the receiving device, so that the data sending rate changes around the network bandwidth. Therefore, the accuracy of the data transmission rate adjustment by the transmitting device is higher. High, without significant fluctuations. Moreover, the transmitting end device transmits the packet data at the adjusted data transmission rate to match the capability of the data transmission path, so that the packet data can be transmitted on the uncongested data transmission path, and the network performance can be fully utilized to avoid Waste of network resources. In addition, the network function entity can be maintained separately without changing the sender device and the sink device.

FIG. 6 is a schematic structural diagram of an embodiment of a network device according to the present invention. As shown in FIG. 6, the network device in this embodiment includes: an obtaining module 11, a processing module 12, and a sending module 13, where the obtaining module 11 is configured to acquire a sending end device. And the network bandwidth information of the data transmission path between the device and the receiving device; the processing module 12 is configured to adjust the data sending rate according to the network bandwidth information acquired by the acquiring module 11; the sending module 13 is configured to adjust the processing according to the processing module 12 Number Packet data is transmitted to the receiving device according to the transmission rate.

The network device of this embodiment may be used to implement the technical solution of the first embodiment of the congestion control method shown in FIG. 1, and the implementation principle is similar to the technical effect, and details are not described herein again.

Further, in another embodiment of the network device of the present invention, the obtaining module 1 1 may be specifically configured to calculate, according to the received confirmation information in the acknowledgement message sent by the receiving device and the receiving time of the acknowledgement message, Calculating the network bandwidth information; or calculating and acquiring the network according to the received confirmation information in the confirmation message sent by the receiving end device, the time information included in the subsequent confirmation message, and the time information included in the previous confirmation message. And receiving the acknowledgment message sent by the receiving end device, where the acknowledgment message includes network bandwidth information, where the network bandwidth information is obtained by the receiving end device to calculate the data volume of the average received packet data packet per unit time Or obtained from a network function entity having bandwidth measurement or bandwidth management functions; or acquiring the network bandwidth information from a network function entity having bandwidth measurement or bandwidth management functions.

The obtaining module 1 1 can obtain the network bandwidth information in the foregoing manner, and the methods respectively correspond to the second embodiment to the fourth embodiment of the congestion control method shown in FIG. 2 to FIG. 4, and the implementation principle and technical effects are similar, and details are not described herein again. .

Figure Ί is a schematic structural diagram of Embodiment 1 of the congestion control system of the present invention. As shown in Figure ,, the system in this embodiment may include: a sender device 1 and a receiver device 2, where the sender device 1 is configured to acquire a sender device. 1 and network bandwidth information of the data transmission path between the receiving device 2; adjusting the data transmission rate according to the network bandwidth information; and transmitting the packet data to the receiving device 2 according to the adjusted data transmission rate; The device 2 is configured to receive packet data sent by the source device 1.

The system of the present embodiment can be used to implement the technical solution of the first embodiment of the congestion control method shown in FIG. 1, and the implementation principle is similar and technical effects, and details are not described herein again.

In another embodiment of the congestion control system of the present invention, based on the first embodiment of the system, the transmitting device 1 may be specifically configured to be sent according to the received device by the receiving device. Confirming the receipt time of the confirmation information and the confirmation message included in the message, and calculating the network bandwidth information; or receiving the confirmation information in the confirmation message sent by the receiving device, and the time included in the subsequent confirmation message. The information and the time information included in the previous confirmation message are calculated to obtain the network bandwidth information. In this embodiment, the transmitting device 1 and the receiving device 2 can perform the technical solution of the second embodiment of the congestion control method shown in FIG. 2, which has similar implementation principles and technical effects, and details are not described herein again.

Further, in another embodiment of the congestion control system of the present invention, based on the first embodiment of the system, the receiving device 2 can be specifically configured to send an acknowledgement message including network bandwidth information to the transmitting device 1, and the network bandwidth information is a receiving device. 2 Calculate the amount of data of the average received packet data per unit time. In this embodiment, the transmitting device 1 and the receiving device 2 can perform the technical solution of the third embodiment of the congestion control method shown in FIG. 3, and the implementation principle is similar and technical effects, and details are not described herein again.

FIG. 8 is a schematic structural diagram of Embodiment 2 of a congestion control system according to the present invention. As shown in FIG. 8, the system in this embodiment further includes: a network function entity 3, based on the system embodiment 1 shown in FIG. The entity 3 is configured to monitor and acquire network bandwidth information, and send the network bandwidth information to the sending device 1 or send the network bandwidth information to the receiving device 2, and send the data to the transmitting device 1 through the receiving device 2.

In this embodiment, the transmitting end device 1, the receiving end device 2, and the network function entity 3 may perform the technical solution of Embodiment 5 of the congestion control method shown in FIG. 4 or the congestion control method embodiment shown in FIG. 5, The implementation principle is similar and technical effects, and will not be described here.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, and not The invention is described in detail with reference to the foregoing embodiments, and those skilled in the art should understand that the technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced. These modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

Rights request

A congestion control method, comprising:

Obtaining network bandwidth information of a data transmission path between the source device and the receiving device; and adjusting the data transmission rate according to the network bandwidth information;

The packet data is transmitted to the receiving device according to the data transmission rate after the adjustment processing.

The method according to claim 1, wherein the acquiring the network bandwidth information of the data transmission path between the source device and the receiving device includes:

Acquiring the network bandwidth information according to the received time information of the at least two acknowledgement messages sent by the receiving end device and the acknowledgement information included in the at least two acknowledgement messages, where the time information includes the at least two The receipt time of the confirmation message or the time information contained in the at least two confirmation messages.

The method according to claim 1, wherein the acquiring the network bandwidth information of the data transmission path between the transmitting device and the receiving device comprises: applying the formula (1) to obtain the network bandwidth information,

Bandwidth = { ^{8 X [(Seq2} - ¹ ) + (SACK2_block - SACKl_block)] _χ

T ACK2 - T ACK1

Wherein, Bandwidth is the network bandwidth information, Seq2 is the consecutive acknowledgment sequence number of the subsequent acknowledgment message, Seq1 is the consecutive acknowledgment sequence number of the previous acknowledgment message, and SACK2_block is the number of bytes of the selective acknowledgment parameter in the subsequent acknowledgment message, SACK1_block is the number of bytes of the selective acknowledgment parameter in the previous acknowledgment message, T_ACK2 is the time of receiving the subsequent acknowledgment message or the time information contained in the latter acknowledgment message, and T_ACK1 is the reception of the previous acknowledgment message. The time or the time information included in the previous acknowledgment message, where the next acknowledgment message is the last one of the at least two acknowledgment messages sent by the receiving device, where the previous acknowledgment message is sent by the receiving device The previous one of the at least two confirmation messages confirms

The network bandwidth information of the data transmission path between the sender device and the sink device is obtained from a network function entity having a bandwidth measurement or bandwidth management function.

Receiving an acknowledgment message sent by the receiving end device, and acquiring network bandwidth information included in the acknowledgment message; the network bandwidth information is obtained by the receiving end device according to an amount of data of an average received packet data packet per unit time, Or the network bandwidth information is obtained by the receiving end device from a network function entity having a bandwidth measurement or a bandwidth management function.

The method according to claim 5, wherein before the obtaining the network bandwidth information of the data transmission path between the source device and the receiving device, the method further includes:

Sending a connection establishment message to the receiving end device, where the connection establishment message includes a bandwidth parameter indication, where the bandwidth parameter indication is used to indicate that the receiving end device includes the network bandwidth information in the acknowledgement message.

Receiving a connection establishment confirmation message sent by the receiving end device, where the establishing connection confirmation message includes a bandwidth parameter indication.

The method according to any one of claims 1 to 6, wherein the adjusting the data transmission rate according to the network bandwidth information comprises at least one of the following processing modes Ways:

Adjusting the data transmission rate to be equal to the rate of the network bandwidth;

The data transmission rate is adjusted to be greater than the rate of the network bandwidth.

The method according to any one of claims 1 to 6, wherein the adjusting the data transmission rate according to the network bandwidth information comprises:

The data transmission rate is adjusted to be lower than the network bandwidth, and after the network bandwidth information is acquired again, the data transmission rate is adjusted according to the new network bandwidth information.

The ratio of the average size of the transmitted packet data packet to the network bandwidth information is taken as the packet transmission rate of the packet data packet.

The method according to any one of claims 1 to 6, wherein before the acquiring network bandwidth information of the data transmission path between the transmitting end device and the receiving end device, the method further includes: applying an 3) obtaining the data transmission rate,

8 ^x packet _ size _t

Rate = ―

Ty - Tx

(3)

Wherein, Rate represents the data transmission rate during the transmission of the packet data packet X to the transmission packet data packet y by the transmitting device, Ty represents the time at which the packet data packet y is transmitted, and Tx represents the time at which the packet data packet X is transmitted, 8 X packet _ _S ize _t represents the sum of the total number of bits transmitted by the transmitting device during the transmission of the packet data packet X to the transmission of the packet data packet y.

A network device, comprising:

The network device according to claim 11, wherein the acquiring module is specifically configured to obtain, according to the received confirmation information in the confirmation message sent by the receiving end device, and the receiving time of the confirmation message. The network bandwidth information.

The network device according to claim 11, wherein the acquisition module has The method is configured to acquire the network bandwidth information according to the received time information of the at least two acknowledgement messages sent by the receiving end device and the acknowledgement information included in the at least two acknowledgement messages, where the time information includes The receiving time of the at least two acknowledgement messages or the time information included in the at least two acknowledgement messages.

The network device according to claim 11, wherein the acquiring module is configured to receive an acknowledgement message sent by the receiver device, obtain network bandwidth information, and the network bandwidth information from the acknowledgement message. Obtained by the receiving end device according to the data amount of the packet data packet received in an average unit time, or the network bandwidth information is obtained by the receiving end device from a network function entity having a bandwidth measurement or a bandwidth management function.

The network device according to claim 11, wherein the acquiring module is specifically configured to acquire, by using a network function entity having a bandwidth measurement or a bandwidth management function, a data transmission path between the transmitting end device and the receiving end device. Network bandwidth information.

A congestion control system, comprising: a transmitting device and a receiving device,

The sending end device is configured to acquire network bandwidth information of a data transmission path between the sending end device and the receiving end device, and perform adjustment processing on the data sending rate according to the network bandwidth information; Data transmission rate, sending packet data to the receiving device;

The congestion control system according to claim 16, wherein the sending end device is specifically configured to: according to the received time information of the at least two acknowledgement messages sent by the receiving end device, and the at least two The confirmation information included in the confirmation message acquires the network bandwidth information, where the time information includes a reception time of the at least two acknowledgement messages or time information included in the at least two acknowledgement messages.

The congestion control system according to claim 16, wherein the receiving end device is specifically configured to send, to the sending end device, an acknowledgement message including network bandwidth information, where The network bandwidth information is obtained by the receiving end device according to the data amount of the packet data packet received in an average unit time.

The congestion control system according to claim 16, further comprising: a network function entity, configured to monitor and acquire network bandwidth information, and send the network bandwidth information to the sending end device, or The network bandwidth information is sent to the receiving end device, and is sent by the receiving end device to the sending end device.