WO2018145481A1

WO2018145481A1 - Method and device for transmitting packet

Info

Publication number: WO2018145481A1
Application number: PCT/CN2017/105870
Authority: WO
Inventors: 坎图瓦塔瓦苏; 曹振; 陈胜旗
Original assignee: 华为技术有限公司
Priority date: 2017-02-13
Filing date: 2017-10-12
Publication date: 2018-08-16
Also published as: CN108429700B; CN108429700A

Abstract

Provided in embodiments of the present invention are a method and device for transmitting a packet, where a transmitting end of a first TCP connection transmits a first packet of the first TCP connection, the transmitting end determines that a change occurs in link state information of the first TCP connection, the link state information is used for expressing the transmission performance of the TCP connection; an MFL of the first TCP connection is adjusted to a second value on the basis of the change in the link state information; the transmitting end transmits a second packet of the first TCP connection to the correspondent end, and the specification of a TLS record of the second packet is the second value. As such, the specification of the TLS record can be flexibly adjusted on the basis of the network environment, thus allowing increased smoothness in the transmission of data.

Description

Method and device for transmitting message

Technical field

The present invention relates to the field of communications, and more particularly to a method and apparatus for transmitting a message.

Background technique

People's lives are now increasingly inseparable from the Internet, while privacy and security issues are increasingly important. Encryption has always been an important feature to protect the privacy of user communications. SSL (Secure Sockets Layer) and TLS (Transport Layer Security) protocols are widely used protocols. In fact, TLS is an upgraded version of SSL, so the industry sometimes uses SSL to represent TLS. According to data from some foreign research institutions, nearly 60% of network traffic has been encrypted with SSL/TLS. SSL/TLS is used to secure data transmission over the Internet. Data encryption (Encryption) technology ensures that data is not intercepted and eavesdropped during transmission over the network. The SSL/TLS protocol is located between the TCP/IP protocol and various application layer protocols to provide security support for data communication.

SSL is a layer protocol between the application layer and the TCP/IP (Transmission Control Protocol/Internet Protocol) layer. The application data needs to be processed by the SSL layer before the data can pass through the TCP/IP layer. Send it out. In the process of processing through the SSL layer, the application data is processed in units of TLS records (SSL Record), and the TLS record size has a specification limit. When the application data size exceeds the TLS record specification, the SSL protocol divides the application data according to the TLS record. After the fragmentation is completed, the SSL protocol stack compresses each MAC address, adds a MAC address, encrypts and decrypts the data, and so on. The encrypted data is sent to the TCP interface in turn.

However, in the prior art, the specifications of the TLS records used are fixed and cannot adapt to the changing network environment, thereby causing problems such as a long delay in acquiring data by the application layer.

Summary of the invention

In view of this, the embodiments of the present invention provide a method and a device for transmitting a message, which can adjust the specification of the TLS record more flexibly according to the network environment, reduce the delay of acquiring data by the application layer, and make the data transmission more smooth. .

An embodiment of the present invention provides a method for sending a message, where the method includes: sending, by the sending end of the first TCP connection, the first packet of the first TCP connection, where the first TCP connection is the largest. The slice length MFL is a first value, and the MFL indicates a specification of a maximum transport layer security TLS record used by the first TCP connection to transmit data, and the specification of the TLS record of the first packet is the first The value of the link state information of the first TCP connection is changed, the link state information is used to indicate the transmission performance of the TCP connection; and the sender is changed according to the change of the link state information. Adjusting the MFL of the first TCP connection to a second value; the sending end sends the second packet of the first TCP connection to the opposite end of the first TCP connection, and the MFL of the second packet Is the second value.

It should be understood that this TCP connection is any TCP connection that uses the TLS layer to process data. The link state information includes at least one of a round trip delay RTT, a congestion window CWND, and a packet loss ratio.

It should be understood that the sender may send the peer end of the sender to the first TCP connection, that is, the device represented by the destination address in the TCP packet corresponding to the first packet. Alternatively, it may be transmitted to an I/O (input/output) device of a physical machine corresponding to the transmitting end.

In an implementation manner, the MFL ranges from 1300 Bytes to greater than or equal to 16 KB.

In an implementation manner, the sending, by the sending end, adjusting the MFL of the first TCP connection to a second value according to the change of the link state information, including: using the changed link state information, Calculating the range of values of the MFL The probability that the packet corresponding to the multiple values is successfully sent; the MFL of the TCP connection is adjusted to the second value of the plurality of values, and the probability that the packet corresponding to the second value is successfully sent is The maximum value of the probability that the packet corresponding to the multiple values is successfully transmitted.

In an implementation manner, the sending, by the sending end, adjusting the MFL of the first TCP connection to a second value according to the change of the link state information, including: using the changed link state information, Calculating a probability that the packet of the first TCP connection is successfully sent; if the probability is increased, adjusting the MFL of the first TCP connection to a second value, where the second value is greater than the first value a value; the MFL of the first TCP connection is adjusted to a second value if the probability is reduced, wherein the second value is less than the first value.

In an implementation manner, the link state information includes a round-trip delay RTT, and the sending end adjusts the MFL of the first TCP connection to a second value according to the change of the link state information, including Resetting, in the case of the RTT, the MFL of the first TCP connection to a second value, the second value being less than or equal to a first value; if the RTT is decreased, The MFL of the first TCP connection is adjusted to a second value, the second value being greater than or equal to the first value.

In an implementation manner, the MFL is pre-set with a value range, the link state information includes a round-trip delay RTT, and the sending end uses the first TCP according to the change of the link state information. Adjusting the connected MFL to a second value, comprising: adjusting, when the RTT is increased, and the first value is less than a maximum value of the value range, adjusting the MFL of the first TCP connection to Binary value, the second value is half of the first value; in a case where the RTT is decreased, and the first value is greater than a minimum value of the value range, the first TCP is The connected MFL is adjusted to a second value, the second value being twice the first value; in the case where the RTT is increased, and the first value is a maximum value in the range of values Or, if the RTT is decreased, and the first value is a minimum value of the value range, adjusting the MFL of the first TCP connection to a second value, the second value Equal to the first value.

In an implementation manner, the MFL is pre-set with a value range, and the MFL is pre-set with a value range, the link state information includes a congestion window CWND, and the change according to the link state information is performed. Adjusting, by the sending end, the MFL of the first TCP connection to a second value, including: adjusting, when the CWND is increased, the MFL of the first TCP connection to a second value, the second value The first value is less than or equal to; in the case that the CWND is decreased, the MFL of the first TCP connection is adjusted to a second value, and the second value is greater than or equal to the first value.

In an implementation manner, the MFL is pre-set with a value range, the link state information includes a congestion window CWND, and the sending end connects the first TCP according to the change of the link state information. Adjusting the MFL to the second value, including: adjusting, in the case that the CWND is increased, the MFL of the first TCP connection to a second value, where the second value is the CWND and the first TCP a product of a maximum message length MSS of the connection, and a smaller value of the first value, wherein, in a case where the product is smaller than a minimum value of the value range, the second value is the a minimum value in the range of values; adjusting the MFL of the first TCP connection to a second value, where the CWND is decreased, the second value being the CWND connected to the first TCP a product of a maximum message length MSS, and a larger value of the first value, wherein, in a case where the product is greater than a maximum value in the value range, the second value is the value The maximum value in the range.

In an implementation manner, the determining the link state information of the first TCP connection is changed, including: detecting link state information of the first TCP connection when receiving a packet or sending a packet, Determining that the link state information changes; or detecting the link state information of the first TCP connection at a preset time or according to a preset time interval to determine that the link state information changes. On the other hand, the link state information may be periodically detected according to a preset time or a preset time interval.

It should be understood that the sender is a terminal or a network device (such as a server), and the terminal or network device can also receive The terminal receives the data. That is to say, the determination of the link state information may be triggered in the form of an event trigger, for example, the event is that a message is received or a message is to be sent. It should be understood that when a message is received or a message is sent, it is indicated that the sender detects the received message or determines that the message is to be sent, due to the running process of the device (for example, the execution of the program or task). The delay should be tolerated.

In the embodiment of the present invention, a method for sending a message is provided, which involves adjusting a size of a TLS record, and the method uses the MFL as a specification of the TLS record, based on the link information of the TCP connection corresponding to the TLS. The value of the MFL is adjusted so that the specification of the TLS record can be flexibly adjusted according to the link state of the TCL connection, which reduces the delay of obtaining data by the application layer, and makes the data transmission smoother, thereby improving the communication performance.

On the other hand, the embodiment of the present invention further provides an apparatus for transmitting a message, where the apparatus includes a sending module, where the sending module is configured to send the first packet of the first TCP connection, the first TCP connection. The maximum fragment length MFL is a first value, and the MFL represents a specification of a maximum transport layer security TLS record used by the first TCP connection to transmit data, and the specification of the TLS record of the first packet is a first value; an adjustment module, configured to determine a change in link state information of the first TCP connection, where the link state information is used to indicate a transmission performance of the TCP connection; the adjustment module is further configured to: Adjusting, according to the change of the link state information, the MFL of the first TCP connection to a second value; the sending module is further configured to send the first TCP connection to a peer end of the first TCP connection a second packet, where the MFL of the second packet is the second value.

Since the device is a device corresponding to the above method, please refer to the foregoing description of the method for explaining various implementations, descriptions and beneficial effects of the device.

In a third aspect, the embodiment of the present invention further provides a device, configured to send a message, where the device includes: a processing circuit, a communication interface, and a storage medium, where the storage medium stores a protocol stack program, and the communication interface For transmitting and receiving information with other devices by executing a program in the storage medium, the processor is configured to implement the methods in the implementations of the first aspect by executing instructions in the storage medium.

In a fourth aspect, there is also provided a storage medium for storing program code for implementing the method of the implementations of the first aspect.

Since the third aspect and the fourth aspect correspond to the method of the first aspect, please refer to the foregoing description of the method for explaining the various implementation manners, descriptions, and beneficial effects of the third aspect and the fourth aspect.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly described below, and those skilled in the art can, without any creative work, Other drawings can be obtained from these figures.

1 is a schematic diagram of a process of processing application data through an SSL layer according to an embodiment of the present invention;

2 is a simplified block diagram of a communication system according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a transmitting end according to an embodiment of the present disclosure;

4 is a schematic diagram of a method according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a device according to an embodiment of the present disclosure;

FIG. 6 is a structural diagram of another apparatus of a transmitting end according to an embodiment of the present invention.

detailed description

The embodiment of the invention provides a method and a device for transmitting a message, and the following will be combined with the drawings in the embodiment of the present invention. The technical solutions in the embodiments of the present invention are clearly and completely described. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The following are some technical terms involved in the embodiments of the present invention:

The CWND congestion window refers to the maximum number of data packets that can be sent at the source end of the data transmission in the case of congestion control. It should be understood that the congestion window is abbreviated as cwnd or CWND. For example, in some code, use cwnd to indicate.

Transport layer security (TLS), a communication security protocol used to protect data transfers between clients and/or server applications. The protocol is located between the application layer and the TCP/IP stack.

The Message Authentication Code (MAC) is a small piece of inspection information used to verify the integrity of a message.

Head of Line blocking (HoL), a phenomenon that limits transmission performance. Some packets caused by, for example, out-of-order transmission or HTTP piplining are caused by other data packets (for example, other data). Packet loss needs to be retransmitted) Delayed reporting to the application layer. It should be understood that the head blocking is abbreviated as HoL or HOL.

RTT (Round-trip Time), round trip delay. It indicates the delay experienced by the transmitting end from the time of transmitting data to the process of receiving the receiving confirmation information (such as ACK or NACK) corresponding to the data sent by the receiving end. It should be understood that, in an implementation manner, the receiving end immediately sends the acknowledgement information corresponding to the data, and the “immediately” should be understood to include the necessary processing time from the receiving end to receiving the acknowledgement message. . It should be understood that the round trip delay can be abbreviated as RTT or rtt. For example, in some code, use rtt.

RTTVAR, a parameter in the tcp_info structure (tcp_info_struct), which is used to describe the performance of the TCP connection, the RTT changes.

Maximum fragment length (MFL), a parameter used to describe the size of the largest TLS record that can be used to transfer data.

MSS, a parameter in the tcp_info structure (tcp_info_struct), which is used to describe the size of the largest fragment of the TCP payload.

MAC, Message Authentication Code. A tool used to guarantee the data integrity of a message.

The technical solution provided by the embodiment of the present invention can be typically applied to a wireless communication system, such as, for example, a Global System of Mobile communication (GSM) network, Code Division Multiple Access (CDMA). Network, Time Division-Synchronous Code Division Multiple Access (TDSCDMA) network, Wideband Code Division Multiple Access (WCDMA) network, General Packet Radio Service (GPRS, General Packet Radio Service) Network, Long Term Evolution (LTE) network, Software Defined Network (SDN), Wireless Sensor Network, etc.

In fact, TLS is an upgraded version of SSL, so the industry sometimes uses SSL to represent TLS. Thereby providing at least one of the following services for communication in the network: authenticating the user and the server, ensuring that the data can be sent to the correct destination (such as a client or server); encrypting the data to prevent the data from being stolen during transmission; maintaining The integrity of the data to ensure that the data is not altered during transmission. TLS is a fundamental protocol included in the operating environment in many commercial deployments. Almost half of Internet traffic is protected by TLS. However, its design does not consider how to effectively use low-latency or low-bandwidth types of networks, such as wireless and telecommunications networks. Because there is a head-of-line (HoL) blocking phenomenon when using TCP protocol transmission, that is, if some data in a packet is lost in transmission, other received data will be saved in The part of the buffer until the lost data is retransmitted successfully will be reported to the application layer. For example, if a packet length is 16K and 1K data is lost during transmission, the remaining 15K data needs to wait for the 1K data to be retransmitted successfully before the data of the packet is provided to the application layer.

The process of processing the data of the application layer by the TLS layer will be described below with reference to FIG. 1, which shows the processing procedure of the application data through the TLS layer. In the TLS protocol, application data is processed in units of TLS records. When the amount of data of the application data to be transmitted exceeds the specification of the TLS record, the TLS layer fragments the application data in units of TLS records, assuming that the data is divided into n slices, the data length of the preceding n-1 fragments, and TLS. The length of the record specification is the same. Finally, the length of the nth slice data may generally be less than the length of one TLS record specification. For the previous n-1 fragments, because the length and the specification length of the TLS record are the same, we call the fragment length at this time the maximum fragment length MFL (Maximum fragment length), due to the maximum fragment length and the TLS record size. The same, the MFL mentioned later, can also be considered as the TLS record size. After the fragmentation is completed, the TLS protocol stack compresses, adds MAC, encrypts and decrypts each record, and finally sends the encrypted data to the TCP interface for transmission.

As can be seen from this flow, the amount of data transmitted by the TLS protocol through tcp is strongly related to the amount of data of the TLS record. If the TLS record specification is larger, the packet sent by a tcp will be larger, if the TLS record specification The smaller, the smaller the packet sent by a tcp.

The TCP protocol requires strict data transmission in order, that is, for a group of data, when a Transport Protocol Data Unit (TPDU) is lost, the subsequent data unit can only wait for the TPDU that has been lost. After retransmission and reception, this set of data will be reported to the application layer. This is the blocking problem of the head (of the head-of-line) of TCP. For example, a packet is processed by the TLS layer, and the data stream is sequentially included as data 1 to data 4. After the data 3 is lost, the peer needs to wait until the source retransmits the data 3 and receives the data 3, that is, After the data in the packet is received, the data 1 to 4 are parsed, and the parsed data is delivered to the application layer.

After receiving the packet, the receiving end processes the TLS layer between the application layer and the TCP protocol layer, specifically encrypting and decrypting the application data and processing the MAC address. For example, in the decryption process, when a TLS record is received, the record is decrypted in the TLS protocol stack, and the MAC address is verified after successful decryption. If data loss occurs during TCP transmission, the TLS decryption process will fail because TLS does not receive a complete TLS record (the TLS can also be configured with no encryption mode, but in this mode, the MAC check of the data When the data is also verified to fail, the TLS decryption and verification will succeed only when the data of the entire TLS record is complete, and the decrypted data can be successfully sent to the application layer for processing.

Under the TLS mechanism, even if the receiver receives 15k data in a record (for example, this record specification is 16k, 1k data loss during transmission), the application layer data cannot be processed at this time, and this time, the HoL problem will be suffered. Only after the lost packet is retransmitted, the TLS can decrypt the data normally after the entire recorded data is received, and the waiting time is a large delay.

Currently, open source implementations in the industry generally use fixed-size TLS record specifications for communication. For example, Section 6.2.1 of the TLS standard document RFC5246 states that the specification of a TLS record cannot exceed 2^14 bytes (16 KB). OpenTLS is the industry's most widely used open source code for implementing TLS. In the OpenTLS implementation, the TLS record size defaults to 16KB, and the size cannot be adjusted. For example, the Mbedtls open source code implementation, Mbedtls implements the TLS layer function, widely used, in the Mbedtls open source code implementation, gives the user the right to configure the specifications of the TLS record, the user is configured during the business initialization phase, not easy to configure Change, that is to say, once the specification of the TLS record is determined, it will be used in the subsequent communication process. If the specification of the TLS record needs to be adjusted, the user can re-initialize the service to reconfigure the specifications of the TLS record. It is only possible to start the business, and this process requires manual participation. It should be understood that the larger the specification of the TSL record, the more data is included in the record, and the easier it is to lose data in the transmission. Users can choose to configure the following five TLS record specifications for user configuration: 512 bytes, 1024 bytes, 2048 bytes, 4096 bytes, 8192 bytes, and 16384 bytes.

However, due to the complex and varied network environment, the above usage may bring a variety of problems. For example, if the link condition is too poor, if the TLS record size is too large, the network delay will be too large and the head of the network will be blocked. If the TLS record size is too small, the network throughput and utilization will be too low. waste.

As can be seen from the above discussion, fragmentation (small fragmentation) and large packet reassembly that occur at the TCP layer can lead to huge delays. When the application data is lost during transmission, it will at least cause an RTT (Round-trip Time) delay. Let's use a test as an example to describe the impact of a packet loss behavior on the size of a TLS record. In this test, the application load of 1600K is used, the TLS server is configured in Hong Kong, the TLS client is configured in Bangalore, and the TLS server and the TLS client are transmitted over a network with an average RTT of 300ms. Based on the client's request, the data is sent from the TLS server via TLS encryption. The following are the test results:

1) The specification (size) of the TLS record is 16K, the packet loss rate is 0.1%, and the total delay is 9.1775121s;

2) The size of the TLS record is 16K, the packet loss rate is 5%, and the total delay is 67.4828414s;

3) The size of the TLS record is 1.5K, the packet loss rate is 0.1%, and the total delay is 13.1105458s.

4) The specification (size) of the TLS record is 1.5K, the packet loss rate is 5%, and the total delay is 78.5495714s.

Therefore, as can be seen from the above results, as the specification of the TLS record increases and the packet loss rate increases, the total delay (handshake + data transmission delay) increases. Even if the specification of the TLS record is simply reduced to a smaller value, there is no reduction in latency, but instead more peaks are generated at high packet loss rates (ie, the delay suddenly increases at some point).

FIG. 2 is a simplified block diagram of a communication system 100 according to an embodiment of the present invention. The communication system 100 is only used as an application scenario of the present invention, and should not be construed as limiting the application scenario of the present invention.

The terms "first", "second", "third", "fourth", etc. (if present) in the specification and claims of the present invention and the above figures are used to distinguish similar objects without being used for Describe a specific order or order.

According to FIG. 2, the communication system comprises: a terminal 10, a server 20 and a network 30; wherein the terminal 10 is connected through an access device, such as a WLAN (Wireless Local Area Network), or a cellular network. The ingress accesses the network 30 and establishes a connection with the server 20 based on a specific network protocol. The server 20 transmits data, such as a video stream, to the terminal 10 using the established connection according to the request of the terminal 10.

A terminal, a device that provides voice and/or data connectivity to a user, including a wireless terminal or a wired terminal. The wireless terminal can be a handheld device with wireless connectivity, or other processing device connected to a wireless modem. For example, the wireless terminal can be a mobile phone (or "cellular" phone) or a computer with a mobile terminal. As another example, the wireless terminal can also be a portable, pocket, handheld, computer built-in or in-vehicle mobile device. For another example, the wireless terminal can be part of a mobile station (mobile station) or user equipment (English: user equipment, UE for short). The term "data packet" in the specification and claims of the present invention and the above-mentioned drawings is the basic unit of network transmission, data organized in a certain format. Different types of network protocols have different definitions of packet formats, but in general, a packet can be divided into a header and a payload, where the header contains the necessary data transmission process. Information, such as address information, flag bits, etc., the payload, also known as the data portion, contains the content of the data being sent.

Network 30 may include a public network, a private network, a portion of the Internet, and/or any combination thereof. For the sake of brevity, other portions of network 30 have not been described.

Server 20 can be an application server, a server proxy, a data center server or a gateway. One of ordinary skill in the art will appreciate that a communication system can generally include fewer or more components than those shown in FIG. 2, and FIG. 2 only shows Components that are more relevant to implementations disclosed by embodiments of the present invention. For example, although three terminals 10 and one server 20 are shown in FIG. 2, those skilled in the art will appreciate that a communication system can include any number of terminals and servers.

Figure 3 shows the main components of the transmitting end of the embodiment of the present invention. The transmitting end may be a server or a terminal. The following is a description of the sending end as a server. According to FIG. 3, the transmitting end includes a processor 201, a memory 202, and a network card (network). Interface card, NIC) 203. The executable 202 is stored in the memory 202, and the executable program 21 includes an operating system and an application. The processor 201 can execute the executable program 21 in the memory 202 to implement a particular function. To establish a communication connection between the sender and the receiver and to transmit data packets based on the established connection, a variety of network protocols must be used. These protocols are combined in a hierarchy to form a protocol suite, and the components implementing the protocol family function are called It is a protocol stack. As shown in FIG. 3, the server 20 and the terminal 10 include a protocol stack 204 and a protocol stack 11, respectively. After the data packet is processed by the protocol stack 204, it is sent to the terminal 10 through the transmitting circuit 231 of the network card 203. The receiving circuit 232 receives the data packet of the application 12 running on the terminal 10 and transmits it to the protocol stack 204 for processing. Wherein, the protocol stack can be implemented by a suitable combination of software, hardware and/or firmware. In one embodiment, the protocol stack 204 and the protocol stack 11 include a TCP/IP (Transmission Control Protocol/Internet Protocol) protocol stack, and the TCP/IP protocol stack refers to a protocol stack implemented by a protocol family defined by the TCP/IP reference model. The protocol family includes two core protocols: TCP (Transmission Control Protocol) and IP (Internet Protocol). According to the definition of the TCP/IP reference model, the protocol family contains protocols that are classified into five abstract "layers": The physical layer, the link layer, the network layer, the transport layer, and the application layer are all defined in the prior art, and are not described in detail in the embodiments of the present invention.

It should be understood that between the TCP/IP protocol stack and the application layer is the SSL layer 13 described above. The SSL layer 13 is only schematically depicted in the terminal in FIG. In the server, the SSL layer can also exist. It should also be understood that in the prior art, the SSL layer in the upper layer cannot know the information of the lower layer (for example, the link state information of the TCP connection, and may include a round trip delay RTT, a congestion window CWND, etc.).

In the solution described in the present application, an adjustment module is deployed under the application layer above the TCP protocol layer, and the module can detect the link state of the TCP connection, thereby adjusting the MFL according to the link state of the connection, so that the MFL flexibly Match the link status of the network connection and improve the performance of the TCP connection, such as transmission delay. It should be understood that this module is used at the origin of the data. Since the TCP connection is used for transmitting data, the data may be transmitted between the network devices or between the network device and the terminal, and the network device may be the server described above, or may be other devices in the network that can run the application layer. device. In a TCP connection, a network device or a terminal may be the origin of data.

The adjustment module can be a set of programs inserted in the TLS layer, or a thread, process, or container for implementing the above functions. This application file does not limit the specific implementation of the adjustment module.

That is to say, the solution described in the present application provides a method for adjusting the size of a TLS record, which is based on information of a TCP layer (for example, tcp_info_struct), and the information of these TCP layers can be in actual communication process. , continuously learn from TCP data and get it. For example, the method uses at least one of the RTTVAR or CWND parameters to adjust the specifications of the TLS record. It learns from the delay of TCP data, specifications, or changes in the congestion window, so that the length of the packet can be changed multiple times. Therefore, the length of the packet can match the TCP window. In this way, the bottleneck of HoL due to larger size packets can be overcome to some extent. In one implementation, the default MFL record specification can be maintained during the handshake process. Once the handshake process is completed, the TLS record specification can be adjusted according to RTTVAR during the application data transmission process.

Moreover, those skilled in the art will appreciate that server 20 may include fewer or more components than those shown in FIG. 3, and FIG. 3 only shows more relevant to the various implementations disclosed in the embodiments of the present invention. component.

Hereinafter, the communication process involved in the present application will be briefly described. First, since SSL is based on the TCP protocol for data transmission, between the receiving end and the originating end of the data transmission (that is, the client and the server), it is necessary to establish a TCP link first, that is, Three-way handshake (TCP Handshake). Next, perform an SSL handshake, including Client/Server key exchange, Cert/Key/Cipher spec Negotiation and Exchange, and Handshake Complete. )three phases. During the SSL handshake process, the client and server need to complete the SSL link establishment. The TLS record specifications are not dynamically adjusted during this phase. As shown in Figure 4, in an implementation manner, before the SSL is established, the sender configures the default MFL. After the SSL handshake is established, the sender sends the data to the receiver using the default MFL. In technology, the connection will always use the MFL to fragment the application data. In the method provided by the present application, as the data packet is transmitted, the transmitting end adjusts the size of the MFL, so that the transmitting end can use the adjusted MFL fragment data. Adjusting the MFL can be considered as the function of the above adjustment module. In other words, the specification of the TLS record is equal to the MFL. Adjusting the value of MFL is to adjust the specifications of the TLS record.

That is, the present application describes a method for transmitting a message, the method comprising: sending, by the sending end of the first TCP connection, the first packet of the first TCP connection, the maximum fragment length of the first TCP connection The MFL is a first value, and the MFL indicates a specification of a maximum transport layer security TLS record used by the first TCP connection to transmit data, and a specification of the TLS record of the first packet is the first value; Determining, by the sending end, that the link state information of the first TCP connection is changed, the link state information is used to indicate a transmission performance of the TCP connection; according to the change of the link state information, the sending end is to be The MFL of the first TCP connection is adjusted to a second value; the sending end sends the second packet of the first TCP connection to the opposite end of the first TCP connection, where the MFL of the second packet is the Two values.

The first TCP connection is a TCP connection.

The method for transmitting a message, which involves adjusting a size of a TLS record, the method uses the MFL as a specification of the TLS record, and adjusts the value of the MFL based on the link information of the TCP connection corresponding to the TLS, thereby causing the TLS record The specifications can be flexibly adjusted according to the link state of the TCL connection, which reduces the delay of obtaining data by the application layer, and makes the data transmission smoother, thereby improving the communication performance.

The link state information includes at least one of a round trip delay RTT, a congestion window CWND, and a packet loss ratio.

The value range of the MFL is greater than or equal to 1300 Bytes and less than or equal to 16 KB.

In an implementation manner, the transmitting end adjusts the MFL of the first TCP connection to a second value according to the change of the link state information, including: using the changed link state information, Calculating a probability that the packet of the first TCP connection is successfully sent; if the probability is increased, adjusting the MFL of the first TCP connection to a second value, where the second value is greater than the first value a value; the MFL of the first TCP connection is adjusted to a second value if the probability is reduced, wherein the second value is less than the first value.

Specifically described below according to P _x (L) takes the MFL match the current link state may refer to the relevant paragraphs.

For details, refer to the description of the relevant paragraphs of the MFL that match the current link state according to P _x (L), and related codes.

In an implementation manner, the MFL is pre-set with a value range, the link state information includes a round-trip delay RTT, and the sending end uses the first TCP according to the change of the link state information. Adjusting the connected MFL to a second value, comprising: adjusting, when the RTT is increased, and the first value is less than a maximum value of the value range, adjusting the MFL of the first TCP connection to Binary value, the second value is half of the first value; in a case where the RTT is decreased, and the first value is greater than a minimum value of the value range, the first TCP is The connected MFL is adjusted to the second a value, the second value being twice the first value; in the case where the RTT is increased, and the first value is a maximum value in the value range, or, in the RTT And decreasing, and if the first value is a minimum value in the value range, adjusting the MFL of the first TCP connection to a second value, the second value being equal to the first value.

Specifically, the link state can be measured by rtt later, so that the rtt change affects the relevant paragraph of the MFL change.

In an implementation manner, the MFL is pre-set with a value range, the link state information includes a congestion window CWND, and the sending end connects the first TCP according to the change of the link state information. Adjusting the MFL to a second value, comprising: adjusting, when the CWND is increased, the MFL of the first TCP connection to a second value, the second value being less than or equal to a first value; in the CWND In the case of a decrease, the MFL of the first TCP connection is adjusted to a second value, and the second value is greater than or equal to the first value.

Specifically, the link state can be measured by CWND in the following text, so that the CWND change affects the relevant paragraph of the MFL change.

In an implementation manner, the determining the link state information of the first TCP connection is changed, including: detecting, when receiving a packet or sending a packet, link state information of the first TCP connection, Determining that the link state information changes; or detecting link state information of the first TCP connection according to a preset time or a preset time interval to determine that the link state information changes.

For details, reference may be made to the following description of the adjustment module using a plurality of ways to trigger the adjustment of the paragraph of P _x (L).

The implementation of the method described above is specifically described below. To implement these implementations, the adjustment module described above needs to be added.

The scheme of the present application can be considered to measure the link state to dynamically adjust the MFL according to the link state. The main logic of its implementation is as follows:

The link state is measured using the probability P (i.e., P _x (L)), where P _x (L) represents the probability that a packet of data amount X is transmitted successfully in the case where the link state is L. It should be understood that P _x (L) should actually be P(X, L), which is a binary function related to X and L, but for the convenience of analysis, one of the two variables is often fixed, and another variable is discussed. The relationship with P, for example, when focusing on the relationship between L and P, is written as P _x (L). In the analysis below, X is used to represent the MFL, that is, the size of TLS record used to identify the TLS record.

It should be understood that the probability of successfully transmitting the data packet indicates that the data packet is successfully transmitted from the originating end to the receiving end at one time without any problems such as packet loss or retransmission. Where P _x (L) is related to link state L, and L can be measured by factors such as round trip delay (RTT), loss rate, congestion window (CWND), etc. L is larger, indicating link status. The worse, so P _x (L) will be smaller accordingly. Specifically, follow the rules below

(a) When the round-trip delay RTT of the link becomes large, L becomes large, and P _x (L) becomes small;

(b) When the loss rate of the packet loss rate becomes larger, L becomes larger, and P _x (L) becomes smaller;

(c) When the congestion window CWND becomes large, L becomes large, and P _x (L) becomes small.

For example, in one implementation, it can be assumed here that when the packet size is fixed to X, P _x (L) and link state L are power-rate distribution relations, that is, P _x (L)=cL ^-r , where , c, r are constants greater than zero.

The adjustment module can trigger adjustments P _x (L) in a number of ways. For example, it can be an event trigger mechanism. Specifically, when the sending end sends the application data through the TLS layer, or the receiving end receives the application data through the TLS layer, the current link state is detected. Of course, the link state may also be saved. In this way, when the originating end sends the application data through the TLS layer, or the receiving end receives the application data through the TLS layer, it compares with the previously recorded link status, in the case of a link state change (for example, detecting RTT, loss rate, and CWND) At least one of the changes occurs, and according to the above rule, the value of P _x (L) is adjusted using the relationship between the preset link state and P.

It should be understood that when the transmitting end sends the application data through the TLS layer, or the receiving end receives the application data through the TLS layer, it indicates that the sending end sends the application data through the TLS layer, or the receiving end receives the application data through the TLS layer. Or a short period of time after the above events occur (it should be understood that the delay due to program execution, or processing delay can be tolerated).

In another implementation, a timer mechanism can also be used to trigger. Specifically, the time threshold may be set, and when the timer runs beyond the time threshold, the current link state is detected and compared with the previously recorded link state. (It should be understood that, in the case that the timer expires, Record the detected link status). Then, when the link state change is detected (for example, at least one of the RTT, the loss rate, and the CWND is detected to change), according to the above rule, the relationship between the preset link state and the P is used to adjust the P. The value of _x (L), and restart the timer to wait for the next timeout, and then detect the link state.

It should be understood that other methods may be used to trigger the adjustment of the value of P _x (L), which is not limited in the embodiment of the present invention.

The adjustment module can adjust the value of the MFL based on the change in P _x (L). It should be understood that _X in P _x (L) represents the amount of data of the packet. Since the data packet is encapsulated using MFL specifications, so in the case where P _x (L) takes a value, which is P _x (L) corresponding to the value of X is a value corresponding to the MFL P _x (L) . In one implementation, the MFL is first set to a suitable range of values, that is, the MFL is always within this range regardless of how the subsequent MFL changes. Specifically, the Min_MFL=1300 bytes and Max_MFL=16384 bytes are set, and the MFL ranges from Min_MFL to Max_MFL. This is because: (1) The Maximum Transmission Unit (MTU) in the TCP protocol is generally 1500 bytes (Byte). Because SSL encrypts data, it needs to fill data and add MAC to a record. The operation is such that the original data size before the 1500-byte (TCP) data is encrypted is about 1300 bytes (Byte), so the minimum Min_MFL is 1300 bytes (Byte); (2) The maximum specified in the SSL RFC The TLS record is 16 KB (Byte), so the maximum Max_MFL is taken as 16 KB (Byte).

The adjustment module can use a variety of methods to adjust the MFL based on P _x (L). In one form, the MFL matching the current link state can be taken from P _x (L). For example, according to the foregoing, it is assumed that the range of values of X is: {1300, 2k, 3k, 4k, 5k, 6k, 7k, 8k, 9k, 10k, 11k, 12k, 13k, 14k, 15k, 16k}, it should be understood that 2k means 2KB, 3k means 3KB, 4k means 4KB, and the rest 5k to 16k are similar. . Calculate P _x (L) according to the possible value X of the MFL, and then set the MFL to X corresponding to the maximum P _x (L), that is, MFL=X{Max(P _x (L)), X={1300 , 2k, 3k...16k}}. In one case, if it is calculated that the transmission probabilities of multiple Xs are equal and greater than the values of other Xs, that is, if there are multiple Xs that can make P _x (L) get the maximum value, then The larger X values of these Xs are taken as MFL (ie, if P _X1 (L) = P _X2 (L) = MAX (P _x (L)), but X2 > X1, then MFL = X2). This way can theoretically ensure that the currently selected MFL value corresponds to the highest probability of successful transmission.

In another implementation, an exponential relationship adjustment can be used, that is, the MFL changes exponentially with a change in P _x (L). For example, when L changes to cause P _x (L) to become larger, MFL is adjusted to twice the original value of MFL; when L changes to cause P _x (L) to become small, MFL is adjusted to the original value of MFL. One; when there is no change in P, there is no change in MFL. It should be understood that the range of the MFL is always within the preset range, that is, [1300 bytes, 16384 bytes].

In another implementation, it can be adjusted in a progressive manner. For example, when P _x (L) becomes larger, the MFL is adjusted to the product of CWND and MSS, and the larger value among the original values of the MFL is expressed by formula, that is, MFL=Max(old_MFL, CWND*MSS); When P _x (L) becomes small, the MFL is adjusted to the product of CWND and MSS, and the smaller of the MFL original values, which is expressed by formula, that is, MFL=min(old_MFL, CWND*MSS); when P is absent When changing, the MFL has no change. It should be understood that the range of the MFL is always within the preset range, that is, [1300 bytes, 16384 bytes].

It should be understood that other methods may be used to adjust the value of the MFL according to P _x (L), which is not limited in the embodiment of the present invention.

On the other hand, the probability of successful data transmission can be considered from the perspective of the amount of data (or the number of data). That is to say, the specification of the TLS record (indicated by S, that is, the MFL) can also be adjusted in the following manner. It is assumed that Pr_s(K) is the probability that data K is successfully transmitted in a TLS record, and that the data arranged before the data K in the TLS record has been successfully transmitted. The data K can be understood as the number of the TCP data of the data at the receiving end is K. It should be understood by those skilled in the art that the actual size refers to the size of the data included from the data numbered 1 to the data K. The unit of K is KB. For example, K=1, that is, Pr_s(K) can be considered as the probability of successful transmission of 1Kb of data. In other words, the meaning of Pr_s(K) is P _x (L) as described above, and K can be regarded as _X in P _x (L). That is, the specification (S) of the TLS record can be expressed by K, where Pr_s(K) is related to at least one of the RTT, the loss rate, and the congestion window (cwnd). A change in CWND causes a change in Pr_s(K). For example, if cwnd increases, Pr_s(K) decreases. On the other hand, a change in the packet loss rate also causes a change in Pr_s(K). For example, if the packet loss rate increases, Pr_s(K) decreases. That is, S will change with Pr_s(K), and Pr_s(K) will vary with link quality parameters such as RTT, loss rate, and congestion window (cwnd).

If Pr_s(K) decreases, S also decreases. Let K=1, 2, 4, 8, 16 and Pr_s(K=1)>Pr_s(K=2)>Pr_s(K=4)>Pr_s(K=8)>Pr_s(K=16). Usually, the initial value will start from a value that is smaller than K, for example, K = 1, so that more data cannot be flooded into the network. At each updated time point, S is updated to S_i such that S_i=i max{Pr_s(K=i), i=1, 2, 4, 8, 16}, that is, the value of K is updated. In order to obtain the point in time of the update, Pr_s(K) can be made to take the corresponding value of K of the maximum value.

The following describes the method by which the adjustment module performs the adjustment of the MFL value in combination with the code. First, explain the definition of some of the parameters involved in the following code:

a) curr_mfl is the maximum fragment length (MFL) used for current data transmission.

b) default_mfl is the default value of MFL. For example, it can be 16K.

c) max_mfl is the maximum value that MFL can increase to.

d) min_mfl is the minimum value that the MFL can be reduced to.

e) new_mfl is the new value of the MFL to be set for data transmission.

f) curr_rtt is estimated from tcp_info, the current value of rtt.

g) prev_rtt is the previous value of rtt, which is estimated during the last message transmission.

h) curr_cwnd is the current value of cwnd estimated from tcp_info.

i) prev_cwnd is the previous value of cwnd, which is estimated during the last message transmission.

j) MSS is the value of the largest segment estimated from tcp_info.

In one implementation, the link state is measured by rtt such that the rtt change affects the MFL change. For example, can this Sample design: MFL has a preset initial value, and the range of MFL is limited to {1300, 2k, 4k, 8k, 16k}. It should be understood that 2k represents 2KB, 4k represents 4KB, and the remaining 8k, 16k are similar. When it is detected that rtt becomes large, indicating that the link condition is deteriorated, the MFL is reduced to half of the original value (that is, the value before the change of rtt) (but for the MFL is 2k, due to the value range limitation, MFL The value is reduced to 1300 bytes. When the rtt is detected to be small, indicating that the link condition is good, the MFL is expanded to twice the original value (but for the MFL is 1300 bytes, due to the value range limitation, The MFL is expanded to 2k); if the TCP link status is detected to have other changes or if the TCP link status is not detected to change, the MFL size is maintained.

In one case, the C language design code is as follows:

In another case, in the initialization phase, some parameters are assigned initial values, wherein curr_mfl is set to default_mfl, that is, a preset value is set to the MFL, max_mfl is set to 16 KB, and min_mfl is 1300 Byte. Then you can use the following code to achieve:

That is, when the rtt change is detected, only the original value of the MFL (ie, the value before the change of rtt, that is, curr_mfl) is greater than min_mfl (ie, 1300 Byte), or the original value of the MFL is less than max_mfl (ie, 16 KB). In the case of the MFL, otherwise the value of the MFL is changed (ie, curr_mfl=1300Byte or curr_mfl=16KB), and the value of the MFL does not change even if rtt changes. It should be understood that for the above code to be able to adjust the MFL value according to the rtt change, the default_mfl should be set to a value greater than min_mfl less than max_mfl.

In another implementation, the link state is measured by cwnd, such that the cwnd change affects the MFL change. For example, it can be designed to estimate the current cwnd value according to the trigger condition (such as timing). If the cwnd value is found to change, then the MFL is assigned a new value, that is, the original value of the MFL is increased or decreased (ie, Cwnd The value before this change, which is curr_mfl). In an implementation manner, in the initialization phase, some parameters are assigned initial values, wherein curr_mfl is set to default_mfl, that is, a preset value is first set to the MFL, max_mfl is set to 16 KB, and min_mfl is 1300 Byte. In addition, MSS can be introduced to control changes in MFL values along with cwnd. It can be implemented with the following code:

That is to say, in the case where cwnd becomes smaller, that is, the detected cwnd is smaller than the previous cwnd (curr_cwnd<prev_cwnd), if the product of the current cwnd and the MSS (curr_cwnd*MSS) is smaller than min_mfl, the MFL is adjusted (new_mfl). ) is min_mfl, that is, to ensure that the value of MFL is not less than the preset minimum value; if the current product of cwnd and MSS is less than curr_mfl (the original value of MFL), then adjust MFL(new_mfl) as the product of cwnd and MSS; in other cases Next, the original value of the MFL is not changed (new_mfl=curr_mfl).

In the case where cwnd becomes larger, that is, the detected cwnd is larger than the previous cwnd (curr_cwnd>prev_cwnd), if the current product of cwnd and MSS (curr_cwnd*MSS) is greater than max_mfl, the MFL (new_mfl) is adjusted to max_mfl, That is, the value of the MFL is not greater than the preset maximum value; if the current product of cwnd and MSS is greater than curr_mfl (the original value of the MFL), the MFL (new_mfl) is adjusted to be the product of cwnd and MSS; in other cases, the value is not changed. The original value of the MFL (new_mfl=curr_mfl).

In other cases, that is, if cwnd is unchanged, or if there is a change in the TCP link state or if there is no change in the TCP link state detected, the MFL size is maintained.

In summary, the solution described in the present application provides a method for transmitting a message, which involves adjusting a size of a TLS record, and the method uses the MFL as a specification of the TLS record, based on the chain of the TCP connection corresponding to the TLS. The road information adjusts the value of the MFL so that the specification of the TLS record can be flexibly adjusted according to the link state of the TCL connection, so that the data transmission is smoother, thereby improving the communication performance.

On the other hand, as shown in FIG. 5, the present application describes a device 500 for transmitting a message, the device 500 includes a sending module 501 and an adjusting module 502, wherein the sending module 501 is configured to send the first TCP connection. a first packet, a maximum fragment length MFL of the first TCP connection is a first value, and the MFL indicates a specification of a maximum transport layer security TLS record used by the first TCP connection to transmit data, where The specification of the TLS record of a message is the first value;

The adjusting module 502 is configured to determine that link state information of the first TCP connection changes, the link state information For indicating the transmission performance of the TCP connection; and adjusting the MFL of the first TCP connection to a second value according to the change of the link state information; the sending module 501 is further configured to connect to the first TCP connection Sending, by the terminal, the second packet of the first TCP connection, where the MFL of the second packet is the second value.

In an implementation manner, the adjusting module 502 is configured to determine that the link state information of the first TCP connection changes when the device receives the packet or sends a packet.

In another implementation manner, the adjusting module 502 is configured to periodically determine that the link state information of the first TCP connection changes at a preset time or according to a preset time interval.

The link state information includes at least one of a round trip delay RTT, a congestion window CWND, an average congestion window, and a packet loss ratio.

It should be understood that the sending device may send, to the first TCP connection, the opposite end (that is, the receiving end) of the transmitting end, that is, the device represented by the destination address in the TCP packet corresponding to the first packet. Alternatively, it may be transmitted to an I/O (input/output) device of a physical machine corresponding to the transmitting end.

The device is a device corresponding to the method embodiment described above. Therefore, regarding various implementations, specific implementation details, and related technical effects of the device, please refer to the foregoing description. In particular, how to adjust the MFL according to the change of the link state information, please refer to the various implementations described above.

It should be understood that, in the device, the adjustment module can be understood as being located between the application layer and the TCP protocol layer, and the adjustment module can be a process or a thread, or can be a piece of executable code.

Thus, the present application provides an apparatus for transmitting a message, which involves adjusting a size of a TLS record. The apparatus uses the MFL as a specification of the TLS record, and adjusts the MFL based on the link information of the TCP connection corresponding to the TLS. The value of the TLS record can be flexibly adjusted according to the link state of the TCL connection, so that the data transmission is smoother, thereby improving the communication performance.

It can be understood that the transmitting end and the receiving end described in the foregoing method embodiments can be implemented by any device having data transceiving capability. For example, the sender can be a terminal or a server. As shown in FIG. 5, the transmitting device 300 includes a processing circuit 302, and a communication interface 304 and a storage medium 320 connected thereto.

The adjustment module mentioned above, and the method for sending a message mentioned above, may be implemented by the processing circuit 302 executing a program in the storage medium 320, which should be understood to involve sending or receiving other devices to other devices. The information processing circuit 302 needs to execute a program in the storage medium 320 to invoke the communication interface 304.

Processing circuitry 302 is used to process data, control data access and storage, issue commands, and control other devices to perform operations. Processing circuitry 302 may be implemented as one or more processors, one or more controllers, and/or other structures that may be used to execute a program or the like. Processing circuitry 302 may specifically include at least one of a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic component. A general purpose processor may include a microprocessor, as well as any conventional processor, controller, microcontroller, or state machine. Processing circuit 302 can also be implemented as a computing component, such as a combination of a DSP and a microprocessor.

The storage medium 306 may include a computer readable storage medium such as a magnetic storage device (eg, a hard disk, a floppy disk, a magnetic strip), an optical storage medium (eg, a digital versatile disk (DVD)), a smart card, a flash memory device, a random access memory. (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), registers, and any combination thereof. Storage medium 306 can be coupled to processing circuitry 302 such that processing circuitry 302 can read information and write information to storage medium 306. In particular, storage medium 306 can be integrated into processing circuit 302, or storage medium 306 and processing circuit 302 can be separate.

Communication interface 304 may include circuitry and/or programs to enable two-way communication between user device 300 and one or more wireless network devices (eg, servers). Communication interface 304 can be coupled to one or more antennas (not shown in FIG. 6) and includes at least one receiving circuit 316 and/or at least one transmitting circuit 318. In one embodiment, communication interface 304 may be implemented in whole or in part by a wireless modem.

In accordance with one or more aspects of embodiments of the present invention, processing circuit 302 is adapted to execute protocol stack program 320 stored in storage medium 306 to implement some or all of the steps of the above method embodiments.

It should also be understood that the apparatus 500 is a device that can transmit a TCP message processed through the TLS protocol layer, and may be, for example, a terminal or a network device.

It should also be understood that the apparatus 500 can also be implemented by the transmitting device shown in FIG. For example, the sending module 501 can execute the program in the storage medium 320 by the processing circuit 302 to invoke the communication interface 304. On the other hand, the adjusting module 502 can execute the program execution in the storage medium 320 by the processing circuit 302. As another example, the TCP/IP protocol stack or the like mentioned above may be stored in the storage medium 320.

The foregoing is a detailed description of a method and an apparatus for transmitting a message according to an embodiment of the present invention. The principles and implementation manners of the present invention are described in the following, and are generally described by those skilled in the art. The present invention is not limited by the scope of the present invention.

Claims

A method for sending a message, the method comprising:

The sending end of the first TCP connection sends the first packet of the first TCP connection, the maximum fragment length MFL of the first TCP connection is a first value, and the MFL indicates that the first TCP connection is used for transmission The specification of the maximum transport layer security TLS record of the data, the specification of the TLS record of the first packet is the first value;

The sending end determines that the link state information of the first TCP connection changes, and the link state information is used to indicate the transmission performance of the TCP connection;

The transmitting end adjusts the MFL of the first TCP connection to a second value according to the change of the link state information;

The sending end sends the second packet of the first TCP connection to the opposite end of the first TCP connection, where the MFL of the second packet is the second value.
The method according to claim 1, wherein the link state information comprises at least one of a round trip delay RTT, a congestion window CWND, and a packet loss ratio.
The method according to claim 1 or 2, wherein the MFL has a value range of 1300 Bytes or more and 16 KB or less.
The method according to any one of claims 1 to 3, wherein the transmitting end adjusts the MFL of the first TCP connection to a second value according to the change of the link state information, including:

Calculating, by using the changed link state information, a probability that a packet corresponding to the multiple values in the MFL value range is successfully sent;

The MFL of the TCP connection is adjusted to a second value of the plurality of values, and the probability that the packet corresponding to the second value is successfully sent is the probability that the packet corresponding to the multiple values is successfully sent. The maximum value.
The method according to any one of claims 1 to 3, wherein the transmitting end adjusts the MFL of the first TCP connection to a second value according to the change of the link state information, including:

Calculating, by using the changed link state information, a probability that the first TCP connection is successfully sent;

Adjusting, in the case of the increased probability, the MFL of the first TCP connection to a second value, wherein the second value is greater than the first value;

In case the probability is reduced, the MFL of the first TCP connection is adjusted to a second value, wherein the second value is smaller than the first value.
The method according to any one of claims 1 to 3, wherein the link state information comprises a round-trip delay RTT, and the transmitting end will be the first according to the change of the link state information The MFL of the TCP connection is adjusted to the second value, including:

In the case that the RTT is increased, the MFL of the first TCP connection is adjusted to a second value, and the second value is less than or equal to the first value;

In the case that the RTT is reduced, the MFL of the first TCP connection is adjusted to a second value, and the second value is greater than or equal to the first value.
The method according to any one of claims 1 to 3, wherein the MFL is pre-set with a value range, the link state information includes a round-trip delay RTT, and the change according to the link state information The sending end adjusts the MFL of the first TCP connection to a second value, including:

And adjusting, when the RTT is increased, and the first value is smaller than a maximum value of the value range, adjusting the MFL of the first TCP connection to a second value, where the second value is Half of the first value;

And adjusting, when the RTT is decreased, and the first value is greater than a minimum value of the value range, adjusting the MFL of the first TCP connection to a second value, where the second value is Double the first value;

In a case where the RTT is increased, and the first value is a maximum value in the value range, or the RTT is decreased, and the first value is in the value range In the case of the minimum value, the MFL of the first TCP connection is adjusted to a second value, the second value being equal to the first value.
The method according to any one of claims 1 to 3, wherein the MFL is pre-set with a value range, the link state information includes a congestion window CWND, and the change according to the link state information, The sending end adjusts the MFL of the first TCP connection to a second value, including:

When the CWND is increased, adjusting the MFL of the first TCP connection to a second value, where the second value is less than or equal to the first value;

In the case that the CWND is reduced, the MFL of the first TCP connection is adjusted to a second value, and the second value is greater than or equal to the first value.
The method according to any one of claims 1 to 3, wherein the MFL is pre-set with a value range, the link state information includes a congestion window CWND, and the change according to the link state information, The sending end adjusts the MFL of the first TCP connection to a second value, including:

And increasing, in the case that the CWND is increased, the MFL of the first TCP connection to a second value, where the second value is a product of the CWND and a maximum packet length MSS of the first TCP connection, And a smaller value of the first value, wherein, in a case where the product is smaller than a minimum value of the value range, the second value is a minimum value of the value range;

And adjusting, in the case that the CWND is reduced, the MFL of the first TCP connection to a second value, where the second value is a product of the CWND and a maximum message length MSS of the first TCP connection, And a larger value of the first value, wherein, in a case where the product is greater than a maximum value in the value range, the second value is a maximum value in the value range.
The method according to any one of claims 1 to 9, wherein the determining the link state information of the first TCP connection changes comprises:

When receiving the packet or sending the packet, detecting link state information of the first TCP connection to determine that the link state information changes;

Or detecting link state information of the first TCP connection according to a preset time or a preset time interval to determine that the link state information changes.
An apparatus for transmitting a message, the apparatus comprising:

a sending module, where the sending module is configured to send the first packet of the first TCP connection, where a maximum fragment length MFL of the first TCP connection is a first value, and the MFL is used to indicate the first TCP connection The specification of the maximum transport layer security TLS record for transmitting data, the specification of the TLS record of the first packet being the first value;

An adjustment module, configured to determine a change in link state information of the first TCP connection, where the link state information is used to indicate a transmission performance of the TCP connection;

The adjusting module is further configured to adjust the MFL of the first TCP connection to a second value according to the change of the link state information;

The sending module is further configured to send the second packet of the first TCP connection to the opposite end of the first TCP connection, where the MFL of the second packet is the second value.
The apparatus according to claim 11, wherein said link state information comprises a round trip delay RTT, At least one of a congestion window CWND and a packet loss rate.
The apparatus according to claim 11 or 12, wherein the MFL has a value range of 1300 Bytes or more and 16 KB or less.
The apparatus according to any one of claims 11 to 13, wherein said adjusting said MFL of said first TCP connection to a second value according to said change of said link state information, said adjusting The module is configured to calculate, by using the changed link state information, a probability that a packet corresponding to the multiple values in the MFL value range is successfully sent; and adjusting the MFL of the TCP connection to the multiple The second value of the value, the probability that the packet corresponding to the second value is successfully sent is the maximum value of the probability that the packet corresponding to the multiple values is successfully sent.
The apparatus according to any one of claims 11 to 13, wherein in the adjusting module, the MFL of the first TCP connection is adjusted to a second value according to a change of the link state information. to:

Calculating, by using the changed link state information, a probability that the first TCP connection is successfully sent; and if the probability is increased, adjusting the MFL of the first TCP connection to a second value And wherein the second value is greater than the first value; and if the probability is decreased, adjusting the MFL of the first TCP connection to a second value, wherein the second value is less than the first value.
The apparatus according to any one of claims 11 to 13, wherein the link state information comprises a round trip delay RTT, and the MFL of the first TCP connection is adjusted according to a change of the link state information. For the second value aspect, the adjustment module is used to:

In the case that the RTT is increased, the MFL of the first TCP connection is adjusted to a second value, the second value is less than or equal to a first value; and in a case where the RTT is decreased, the first The MFL of a TCP connection is adjusted to a second value, the second value being greater than or equal to the first value.
The apparatus according to any one of claims 11 to 13, wherein the MFL is pre-set with a value range, and the link state information includes a round-trip delay RTT, in the information according to the link state information. Changing, the aspect of adjusting the MFL of the first TCP connection to a second value, wherein the adjusting module is configured to increase when the RTT is greater than the maximum value of the value range And adjusting the MFL of the first TCP connection to a second value, where the second value is half of the first value;

And adjusting, when the RTT is decreased, and the first value is greater than a minimum value of the value range, adjusting the MFL of the first TCP connection to a second value, where the second value is Double the first value;

In a case where the RTT is increased, and the first value is a maximum value in the value range, or the RTT is decreased, and the first value is in the value range In the case of the minimum value, the MFL of the first TCP connection is adjusted to a second value, the second value being equal to the first value.
The device according to any one of claims 11 to 13, wherein the MFL is pre-set with a value range, and the link state information includes a congestion window CWND, and the change according to the link state information Adjusting the MFL of the first TCP connection to a second value, the adjustment module is used

When the CWND is increased, the MFL of the first TCP connection is adjusted to a second value, the second value is less than or equal to a first value; and in a case where the CWND is decreased, the first The MFL of a TCP connection is adjusted to a second value, the second value being greater than or equal to the first value.
The device according to any one of claims 11 to 13, wherein the MFL is pre-set with a value range, and the link state information includes a congestion window CWND, and according to the change of the link state information, The MFL of the first TCP connection is adjusted to an aspect of a second value, and the adjustment module is used for

Adjusting the MFL of the first TCP connection to a second value, where the CWND is increased, the second value a product of a maximum message length MSS of the CWND and the first TCP connection, and a smaller value of the first value, wherein the product is less than a minimum value of the value range The second value is a minimum value in the range of values;

And adjusting, in the case that the CWND is reduced, the MFL of the first TCP connection to a second value, where the second value is a product of the CWND and a maximum message length MSS of the first TCP connection, And a larger value of the first value, wherein, in a case where the product is greater than a maximum value in the value range, the second value is a maximum value in the value range.
The apparatus according to any one of claims 11 to 19, wherein said adjustment module is used for determining that a change in link state information of said first TCP connection is made

When receiving the packet or sending the packet, detecting link state information of the first TCP connection to determine that the link state information changes;

Or detecting link state information of the first TCP connection according to a preset time or a preset time interval to determine that the link state information changes.
A device for transmitting a message, the device comprising: a processing circuit, a communication interface, and a storage medium, wherein the storage medium stores a protocol stack program, and the communication interface is configured to perform the storage A program in the medium transmits and receives information to and from other devices, the processor being operative to implement the method of claims 1 to 10 by operating instructions in the storage medium.