WO2013117090A1

WO2013117090A1 - Data transmission method and device

Info

Publication number: WO2013117090A1
Application number: PCT/CN2012/083403
Authority: WO
Inventors: 叶波; 来传远
Original assignee: 华为技术有限公司
Priority date: 2012-02-08
Filing date: 2012-10-24
Publication date: 2013-08-15
Also published as: CN102594505A

Abstract

Disclosed are a data transmission method and device, which relate to the field of communications, and are used for avoiding generating fragments when transmitting a data message. The method provided in the present invention comprises: a first network element obtaining the length of an extra message which is added when transmitting a data message; and in the process of establishing a communication channel between the first network element and a second network element, according to the length of the added extra message, modifying a maximum transmission unit (MTU) value determined by the first network element and the second network element, so that the first network element transmits the data message according to the modified MTU value. The present invention is applied to the field of communications, and is used for transmitting a data message.

Description

Data transmission method and device The application is submitted to the Chinese Patent Office on February 8, 2012, and the application number is

201 21 0027471. The priority of the invention is the priority of the Chinese patent application, the entire disclosure of which is incorporated herein by reference. Technical field

The present invention relates to the field of communications, and in particular, to a data transmission method and apparatus. Background technique

The mobile data service based on 3G (3rd-generation mobile communication technology, 3rd-generation) network can meet the needs of users to access broadband network services anytime and anywhere, and the speed of data transmission is fast, which has been favored by the market to a large extent. However, due to the high frequency of 3G and large attenuation, the indoor coverage of 3G networks is not ideal, which directly affects the popularity and promotion of 3G services. In order to ensure the coverage of the 3G network indoors and to ensure the security of users' information, it is necessary to configure an SGW (Securtiy GateWay, Security Gateway) to establish an IPSEC (Internet Protocol Security) tunnel and encrypt the communication data content. . The voice service and the data service in the 3G network can be encrypted by the IPSEC tunnel between the AP (Acess Point) and the SGW as needed, thereby increasing the length of the packet. When the length of the packet is too long, the AP needs to perform fragmentation processing on the packet for fragment transmission. When the fragment transmission is used, the transmission delay occurs during the transmission, which increases the burden on the AP. If there are too many slices, the load of the AP will be exceeded, which will cause the transmission of the packet to fail and reduce the stability of data transmission. Summary of the invention

The embodiment of the present invention provides a data transmission method and device, which can avoid fragmentation of a message that needs to be transmitted, thereby reducing transmission delay and reducing the load of the AP, so as to improve transmission stability and transmission efficiency of the data message.

In order to achieve the above object, embodiments of the present invention use the following technical solutions:

In one aspect, the embodiment of the present invention provides a data transmission method, where the method includes: acquiring, by a first network element, a length of an additional message added when transmitting a data message; During the establishment of the communication channel between the first network element and the second network element, the MTU (Maximum Transmission Unit) determined by the first network element and the second network element according to the length of the added additional message The maximum transmission unit value is modified such that the first network element transmits the data message according to the modified MTU value.

On the other hand, the embodiment of the present invention further provides a data transmission apparatus, including a first network element, where the first network element includes:

An obtaining unit, configured to acquire a length of an additional message added when transmitting a data message;

An MTU modifying unit, configured to determine, according to the length of the added additional packet, the first network element and the second network element, in a process of establishing a communication channel between the first network element and the second network element The maximum transmission unit MTU value is modified such that the first network element transmits the data message according to the modified MTU value.

The data transmission method and device provided by the embodiment of the present invention can modify the MTU value according to the length of the added additional message when the MTU value is negotiated between the first network element and the second network element, so as to avoid the datagram that needs to be transmitted. The text is fragmented. The method provided by the embodiment of the present invention can avoid fragmentation in the process of transmitting data packets, reduce network processing delay, reduce the load of the first network element, and improve transmission stability and transmission efficiency of service data. . DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic flowchart of a data transmission method according to an embodiment of the present invention;

2 is a schematic flowchart of a data transmission method according to another embodiment of the present invention;

3 is a schematic flowchart of a data transmission method according to still another embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a data transmission apparatus according to another embodiment of 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 obvious that the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. 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.

An embodiment of the present invention provides a data transmission method. As shown in FIG. 1, the method includes:

101. The first network element acquires the length of the additional message that is added when the data packet is transmitted.

Specifically, the first network element is a network element device involved in a data transmission process, and may be

The AP (Acess Point) may be another network element device that has a data transmission function. The additional packet may be an encrypted message added when the data packet to be transmitted is encrypted, or may be a preset. The message for other purposes is not limited here.

102. The first network element performs the first network element and the second network element according to the length of the added additional information in the process of establishing a communication channel between the first network element and the second network element. The determined MTU value is modified such that the first network element transmits the data message according to the modified MTU value. The second network element is a device that receives the data packet, and may be an SGW (Securtiy Gate Way) that receives the data packet, or may be another type of data packet receiving device. No restrictions are imposed.

It is worth noting that the MTU value is the maximum amount of data that can be transmitted by a single data packet in the current communication channel determined by the first network element and the second network element when establishing a communication channel according to the TCP protocol. When the data packet needs to be encrypted in the data transmission process, the encrypted packet is added to the data packet, so that the length of the entire packet is increased, so that the first network element transmits the encrypted packet. The need for fragmentation increases the load on the first network element and increases the transmission delay.

Specifically, in the data transmission method provided in this embodiment, the modified MTU value is smaller than the initial MTU value, so that when the data packet to be transmitted by the first network element is encrypted, the packet length is increased, The data packet to be transmitted is fragmented, where the initial MTU value is determined by the first network element and the second network element after being negotiated according to a Transmission Control Protocol (TCP).

In the data transmission method provided by the embodiment of the present invention, when the MTU value is negotiated between the first network element and the second network element, the first network element can modify the MTU value according to the length of the added additional message to avoid the need for the data. The message to be transmitted is fragmented. The method provided by the embodiment of the present invention can avoid fragmentation in the process of transmitting data packets, reduce network processing delay, reduce the load of the first network element, and improve transmission stability and transmission efficiency of service data. . Another embodiment of the present invention provides a data transmission method. As shown in FIG. 2, the method includes:

201. The first network element receives a data packet sent by the terminal.

Specifically, the first network element may be an AP (Acess Point), but is not limited thereto; the terminal may be a smart phone, a tablet, or the like. Generally, the terminal sends the data packet to be transmitted to the first network element through an air interface, so that the first network element encrypts the data packet to ensure information security of the user data. Optionally, the terminal may also be other terminal devices such as a notebook computer.

202. The first network element acquires, according to a preset rule, a length of the additional message that is added when the data packet is transmitted.

Specifically, the additional packet includes a packet header of a TCP packet specified by a Transmission Control Protocol (TCP), and an encrypted packet added when the data packet to be transmitted is encrypted according to a preset rule, but Not limited to this. For example, if the communication data packet is IPSEC encrypted during data transmission, an encrypted message needs to be added to the communication data packet to ensure the security of the user communication data.

Generally, before the data is transmitted, the three-way handshake is performed according to the TCP protocol to establish a communication channel. The method provided by the embodiment of the present invention may modify the MTU value in the process of establishing a communication channel between the first network element and the second network element. The specific process is as follows:

203. The first network element modifies its own MTU value according to the length of the added additional message, and uses the obtained result as the first modified MTU value. Specifically, the first network element may subtract the length of the additional packet from its own MTU value, and use the obtained result as the first modified MTU value.

The first network element sends a first SY (Synchronize Sequence Numbers) packet to the second network element to complete the first handshake. The first SYN packet is used to notify the second network element to establish a connection. The MTU value of the first network element is included. Specifically, the second network element may be an SGW (Securtiy GateWay, security gateway) that receives the data packet, or may be another type of data packet receiving device, which is not limited herein.

205. The second network element receives the first SYN packet, and returns a first ACK (Acknowledgement) message and a second SYN packet to the first network element to complete a second handshake, where the first ACK is performed. The message is a response message about the first SYN packet, and the second SYN packet is used to indicate that the first network element establishes a connection, where the MTU value of the second network element is included.

The first network element obtains the MTU value of the second network element from the second SYN packet, and subtracts the length of the additional packet from the MTU value of the second network element, and the obtained result is obtained. As the second modified MTU value.

207. The first network element compares the first modified MTU value with the second modified MTU value, and selects a smaller value as the modified MTU value, according to the modified The MTU value modifies the MSS (Maximum Segment Size) value in the second SYN packet, and the MSS value is used to characterize the MTU value.

208. The first network element sends a second ACK message to the second network element to complete a third handshake, to establish a communication channel between the first network element and the second network element to transmit a data packet. The second ACK message is a response message about the second SYN packet.

209. The first network element performs encryption processing on the received data packet according to a preset rule to obtain an encrypted data packet. Specifically, after the data packet is encrypted, the encrypted packet is added, so the length of the data packet is increased after being encrypted. Generally, the first network element can establish an IPSEC (Internet Protocol Security) tunnel with the second network element, and perform IPSEC encryption on the data packet.

It is worth noting that the MTU value is the maximum amount of data that can be transmitted by a single data packet in the current communication channel determined by the first network element and the second network element when establishing a communication channel according to the TCP protocol. When the data packet needs to be encrypted in the data transmission process, the encrypted packet is added to the data packet, so that the length of the entire packet is increased, so that the first network element transmits the encrypted packet. The need for fragmentation increases the load on the first network element and increases the transmission delay. In the embodiment of the present invention, since the modified MTU value is smaller than the MTU value that can be actually transmitted in the current network, the difference is the length of the increased encrypted message, so when the encrypted data packet is transmitted, Avoid sharding. Optionally, when the MTU value is modified, the first network element may further reduce the modified MTU value, so that the modified MTU value is greater than or equal to the MTU value that can be actually transmitted in the current network, to ensure encryption. The length of the data packet is less than or equal to the maximum packet length that can be transmitted in the current network.

210. The first network element sends the encrypted data packet to the second network element to complete the transmission of the data packet.

It should be noted that the data transmission method provided by the embodiment of the present invention is mainly applied to the uBro networking mode, and can also be applied to an Ethernet network using other networking modes, which is not limited herein.

The method provided by the embodiment of the present invention implements a scenario in which an AP sends a data packet to the SGW. It can be seen that the method provided by the embodiment of the present invention can also implement a scenario in which the SGW sends a data packet to the AP. At this time, the first network element is the SGW, and the second network element is the AP. That is to say, the method provided by the embodiment of the present invention can implement data transmission between two network element devices in a data transmission process, and details are not described herein again.

In the data transmission method provided by the embodiment of the present invention, when the first network element negotiates the MTU value with the second network element, the first network element can modify the MTU value according to the length of the added additional message to avoid the need for transmission. The message is fragmented. The method provided by the embodiment of the present invention can avoid fragmentation in the process of transmitting data packets, reduce network processing delay, reduce the load of the first network element, and improve transmission stability and transmission efficiency of the service data. Another embodiment of the present invention provides a data transmission method. As shown in FIG. 3, the method includes: 301. A first network element receives a data packet sent by a terminal.

Specifically, the first network element may be an AP (Acess Point), but is not limited thereto; the terminal may be a smart phone, a tablet computer, etc. Generally, the data packet that the terminal needs to transmit is The text is sent to the first network element through an air interface, so that the first network element performs encryption processing on the data packet to ensure information security of the user data. Optionally, the terminal may also be other terminal devices such as a notebook computer.

302. The first network element acquires, according to a preset rule, a length of the additional message that is added when the data packet is transmitted.

Specifically, the additional packet includes a packet header of a TCP packet specified by a TCP protocol, and a root The encrypted message added when the data packet to be transmitted is encrypted according to a preset rule, but is not limited thereto. For example, if the communication data packet is IPSEC encrypted during data transmission, an encrypted message needs to be added to the communication data packet to ensure the security of the user communication data.

303. Perform a three-way handshake between the first network element and the second network element according to the TCP protocol to establish a communication channel, and obtain, by the network element device between the first network element and the second network element, the first network. The minimum MTU value allowed to pass between the element and the second network element. Specifically, the second network element may be an SGW that receives the data packet, or may be another type of data packet receiving device, which is not limited herein.

Specifically, the network element device between the first network element and the second network element supports an ICMP (Internet Control Message Protocol) detection, and the first network element and the first network element During the process of establishing a communication channel between the two network elements, the minimum MTU value allowed to pass between the first network element and the second network element is detected. The network element device can automatically detect the minimum MTU value allowed to pass between the first network element and the second network element. The network element device can be a router or a switch, and is not limited thereto.

304. The first network element subtracts the length of the additional packet from the minimum MTU value allowed to pass between the first network element and the second network element, to obtain a modified MTU value, according to the modified MTU. The value is modified for the SYN packet sent during the three-way handshake.

Specifically, the first network element may modify the MSS value in the SYN packet according to the modified MTU value, where the MSS value is used to represent the MTU value.

305. The first network element performs encryption processing on the received data packet according to a preset rule, to obtain an encrypted data packet. Specifically, after the data packet is encrypted, the encrypted packet is added, so the length of the data packet is increased after being encrypted. Generally, the first network element can establish an IPSEC tunnel with the second network element, and perform IPSEC encryption on the data packet.

It is worth noting that the MTU value is the maximum amount of data that can be transmitted by a single data packet in the current communication channel determined by the first network element and the second network element when establishing a communication channel according to the TCP protocol. When the data packet needs to be encrypted in the data transmission process, the encrypted packet is added to the data packet, so that the length of the entire packet is increased, so that the first network element transmits the encrypted packet. The need for fragmentation increases the load on the first network element and increases the transmission delay. In the embodiment of the present invention, since the modified MTU value is smaller than the MTU value that can be actually transmitted in the current network, the difference is the increased encrypted message. Length, so fragmentation can be avoided when transmitting encrypted data packets.

Optionally, when the MTU value is modified, the first network element may further reduce the modified MTU value, so that the modified MTU value is greater than or equal to the MTU value that can be actually transmitted in the current network, to ensure encryption. The length of the data packet is less than or equal to the maximum packet length that can be transmitted in the current network.

306. The first network element sends the encrypted data packet to the second network element to complete the transmission of the data packet.

According to the data transmission method provided by the embodiment of the present invention, the network element device can detect the minimum MTU value allowed to pass between the first network element and the second network element, and the first network element can be configured according to the length of the added additional message. The minimum MTU value is modified to avoid fragmentation of the packets that need to be transmitted. By using the method provided by the embodiment of the present invention, fragmentation can be avoided in the process of transmitting data packets, network processing delay can be reduced, load of the first network element can be reduced, and transmission stability and transmission efficiency of service data can be improved. A further embodiment of the present invention provides a data transmission apparatus. As shown in FIG. 4, the data transmission apparatus includes a first network element, and the method of the first network element side in the foregoing method embodiment is implemented. The network element includes:

The obtaining unit 41 is configured to acquire a length of the additional message that is added when the data message is transmitted;

The MTU modifying unit 42 is configured to: when the communication channel is established between the first network element and the second network element, the first network element and the second network element according to the length of the added additional message The determined MTU value is modified such that the first network element transmits the data message according to the modified MTU value. The second network element is a device that receives the data packet.

Specifically, the length of the additional packet acquired by the first acquiring unit 41 may be the datagram. The length of the encrypted message added when the file is encrypted.

The MTU modifying unit 42 is specifically configured to: when the first network element and the second network element perform a three-way handshake according to a Transmission Control Protocol (TCP) to establish a communication channel, according to the additional message The length of the MTU value determined by the first network element and the second network element is modified, so that the first network element transmits the data packet according to the modified MTU value.

Further, as shown in FIG. 5, the MTU modification unit 42 includes a first modification subunit 421, a second modification subunit 422, and a processing subunit 423, where:

The first modification sub-unit 421 is configured to: when the first network element performs the first handshake with the second network element, subtract the length of the additional message from the MTU value of the first network element to obtain the first time The modified MTU value;

The second modification sub-unit 422 is configured to: when the first network element performs a second handshake with the second network element, obtain the MTU value of the second network element, and subtract the MTU value of the second network element from the The length of the additional message is obtained, and the MTU value after the second modification is obtained;

The processing sub-unit 423 is configured to compare the first modified MTU value with the second modified MTU value, and select a smaller value as the modified MTU value, so that the first The network element transmits the data packet according to the modified MTU value.

According to the data transmission apparatus shown in FIG. 4, further, as shown in FIG. 6, the MTU modification unit 42 further includes an MTU acquisition subunit 424 and a third modification subunit 425, where:

The MTU obtaining sub-unit 424 is configured to acquire the foregoing information from the network element device between the first network element and the second network element in the process of establishing a communication channel between the first network element and the second network element. a minimum MTU value allowed to pass between a network element and a second network element, where the network element device supports ICMP detection, and can detect a minimum MTU value allowed to pass between the first network element and the second network element. The network element device may be a router or a switch, which is not limited herein;

The third modification sub-unit 425 is configured to subtract the length of the additional packet from the minimum allowed MTU value to obtain a modified MTU value, so that the first network element is based on the modified MTU value. Transmitting the data message.

It should be noted that the data transmission apparatus provided by the embodiment of the present invention is mainly applied to the uBro networking mode, but can also be applied to an Ethernet network that uses other networking modes, which is not limited herein. The data transmission device provided by the embodiment of the present invention can modify the minimum MTU value allowed to be transmitted between the data transmission devices according to the length of the added additional message to avoid fragmentation of the message to be transmitted. The device provided by the embodiment of the present invention can avoid fragmentation in the process of transmitting data packets, reduce network processing delay, reduce the load of the first network element, and improve transmission stability and transmission efficiency of service data.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general hardware, and of course, by hardware, but in many cases, the former is a better implementation. . Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a readable storage medium, such as a floppy disk of a computer. A hard disk or optical disk or the like includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

Claim WO 2013/117090 PCT/CN2012/083403

A data transmission method, comprising:

The first network element acquires the length of the additional message added when transmitting the data packet;

And a maximum transmission unit MTU determined by the first network element and the second network element according to the length of the added additional information in the process of establishing a communication channel between the first network element and the second network element. The value is modified such that the first network element transmits the data message according to the modified MTU value.

The data transmission method according to claim 1, wherein the additional message is an encrypted message added when the data message is encrypted.

The data transmission method according to claim 2, wherein in the process of establishing a communication channel between the first network element and the second network element, according to the length of the added additional message The MTU value of the maximum transmission unit determined by the first network element and the second network element is modified, so that the first network element transmits the data packet according to the modified MTU value, including:

In the process of the third network element and the second network element performing a three-way handshake according to the transmission control protocol TCP to establish a communication channel, the first network element is configured to the first network element according to the length of the additional packet. The MTU value of the maximum transmission unit determined by the second network element is modified, so that the first network element transmits the data packet according to the modified MTU value.

The data transmission method according to claim 3, wherein in the process that the first network element and the second network element perform a three-way handshake according to a transmission control protocol TCP to establish a communication channel, the Modifying, by the network element, the maximum transmission unit MTU value determined by the first network element and the second network element according to the length of the additional packet, so that the first network element transmits the modified MTU value according to the modified Data message, including:

When the first network element performs the first handshake with the second network element, the MTU value of the first network element is subtracted from the length of the additional packet, and the MTU value after the first modification is obtained;

Obtaining, by the first network element, the second handshake of the second network element, obtaining an MTU value of the second network element, and subtracting an MTU value of the second network element from a length of the additional packet, Obtain the MTU value after the second modification;

Comparing the first modified MTU value with the second modified MTU value, and selecting a smaller value as the modified MTU value, so that the first network element is modified according to the The subsequent MTU value transmits the data message.

The method according to claim 2, wherein, in the process of establishing a communication channel between the first network element and the second network element, according to the length of the added additional message The MTU value of the maximum transmission unit determined by the first network element and the second network element is modified, so that the first network element transmits the data packet according to the modified MTU value, and further includes:

Obtaining, by the network element device between the first network element and the second network element, the first network element and the second network in a process of establishing a communication channel between the first network element and the second network element The minimum MTU value allowed to pass between the elements, wherein the network element device supports the control message protocol ICMP detection, and can detect the minimum MTU value allowed to pass between the first network element and the second network element;

The first network element subtracts the length of the additional packet from the minimum MTU value allowed to pass between the first network element and the second network element, to obtain a modified MTU value, so that the first network The element transmits the data packet according to the modified MTU value.

A data transmission apparatus, comprising a first network element, wherein the first network element comprises: an obtaining unit, configured to acquire a length of an additional message added when transmitting a data message;

The data transmission device according to claim 6, wherein the length of the additional message acquired by the first acquiring unit is the length of the encrypted message added when the data message is encrypted.

The data transmission device according to claim 7, wherein the MTU modification unit is configured to perform a three-way handshake between the first network element and the second network element according to a transmission control protocol TCP to establish a communication channel. The MTU value determined by the first network element and the second network element is modified according to the length of the additional packet, so that the first network element transmits the data packet according to the modified MTU value. .

The data transmission device according to claim 8, wherein the MTU modification unit comprises:

a first modifying subunit, configured to: when the first network element and the second network element perform the first handshake, subtract the length of the additional message from the MTU value of the first network element to obtain the first time The modified MTU value; a second modifying subunit, configured to: when the first network element performs a second handshake with the second network element, obtain the MTU value of the second network element, and subtract the MTU value of the second network element from the The length of the additional message is obtained, and the MTU value after the second modification is obtained;

a processing subunit, configured to compare the first modified MTU value with the second modified MTU value, and select a smaller value as the modified MTU value, so that the first The network element transmits the data packet according to the modified MTU value.

10. The apparatus according to claim 7, wherein the MTU modification unit comprises:

An MTU acquiring subunit, configured to acquire, according to a network element device between the first network element and the second network element, in a process of establishing a communication channel between the first network element and the second network element A minimum MTU value that is allowed to pass between a network element and a second network element, where the network element device supports the control packet protocol ICMP detection, and can detect that the first network element and the second network element are allowed to pass. Minimum MTU value;

a third modification subunit, configured to subtract a length of the additional packet from a minimum MTU value allowed to pass between the first network element and the second network element, to obtain a modified MTU value, so that the first A network element transmits the data packet according to the modified MTU value.