WO2016176818A1

WO2016176818A1 - Method and device for transmitting data

Info

Publication number: WO2016176818A1
Application number: PCT/CN2015/078252
Authority: WO
Inventors: 胡农达
Original assignee: 华为技术有限公司
Priority date: 2015-05-05
Filing date: 2015-05-05
Publication date: 2016-11-10
Also published as: CN107078999A; CN107078999B

Abstract

Disclosed are a method and device for transmitting data. A communication link of a network system applying the method comprises currently an n-number of sub-streams. The method comprises: determining to establish an n+1-ordinal sub-stream on the basis of the load intensity of a current n-number of sub-streams in a communication link, where n is a positive integer; and transmitting a to be transmitted first packet on the n+1-ordinal sub-stream. In addition, the method may further comprise: determining the presence among the current sub-streams of the communication link of a sub-stream having a load intensity less than the first threshold and provided with an available transmission window; and transmitting a to be transmitted second packet on the sub-stream determined. The method and device of embodiments of the present invention for transmitting data determine to establish the new sub-stream on the basis of the load intensity of current sub-streams of the communication link, transmit the packet on the newly established sub-stream, allow the number of sub-streams in the communication link to be adjusted dynamically, balance the load intensity among the sub-streams, and increase the utilization rate and transmission efficiency of the network.

Description

Method and device for transmitting data

Technical field

Embodiments of the present invention relate to the field of communications and, more particularly, to methods and apparatus for transmitting data in the field of communications.

Background technique

Network topologies in modern data centers (such as fat-tree network topologies) provide multiple paths between source and destination nodes, potentially providing conditions for parallel data transfer and increased data transfer throughput. However, the traditional network transmission protocol does not adapt to this, such as the Transmission Control Protocol (TCP), each communication connection only establishes one stream, so only one of the paths can be used for data transmission at the same time. The path diversity of modern data center networks cannot be effectively utilized to improve transmission efficiency.

In order to obtain better transmission performance, a transport layer multipath transmission protocol represented by the Multipath Transmission Control Protocol (MPTCP) has appeared. MPTCP can establish multiple sub-streams for each communication connection. Each sub-flow can potentially transmit in parallel using different paths of the network, and aggregate the idle bandwidth of different paths, thereby achieving better transmission performance.

However, the use of more substreams introduces a new cost to the multipath transport protocol, the magnitude of which is positively related to the number of substreams. Especially when the communication load intensity is small, using too many sub-flows can have serious negative effects. First, the process of creating and destroying too many substreams increases communication latency and control traffic. For a small data communication connection, the original data transmission using a single or a few substreams in a number of Round Trip Time (RTT), creating too many substreams increases the completion time of the entire communication connection. Second, each substream needs to maintain an independent data transmission control block. Too many substreams mean excessive central processing unit (CPU) resources and memory resource consumption. Third, the multi-path transport protocol allows more sub-streams to exist in the network. For some networks (such as Software Defined Networking (SDN)), this will increase the demand for network device flow table capacity. Subflows can cause network device flow table overflows, which can lead to network scalability issues.

At present, the transport layer multipath transmission protocol represented by MPTCP usually uses a fixed number of substreams, and the number of substreams cannot be dynamically adjusted during the lifetime of the communication connection. Since the load strength of the communication connection is usually unknown in advance, the system aggregates the different paths in order to fully utilize the multipath transmission protocol. The ability to idle bandwidth usually sets a larger number of substreams according to the demand of large data traffic transmission. This leads to a small amount of data traffic dominated by the network, using too many substreams, which in turn introduces excessive substream cost. Conversely, if the setting uses only a small number of substreams, the transmission efficiency will be greatly reduced for communication connections with large traffic.

Another problem with the existing transport layer multipath transport protocol is that the shaping of network traffic is neglected, that is, the load strength of each substream in the network is unbalanced. Related studies have shown that the characteristics of data traffic have an important impact on the overall transmission efficiency of the network. For example, for the Equal Cost Multipath (ECMP) technology of the mainstream network load balancing technology, it is easier to achieve high network utilization and high transmission efficiency by scheduling a large number of smooth small stream traffic compared to the network traffic with mixed stream size. . Multi-path transmission protocol has the opportunity to reshape network traffic characteristics due to the use of multiple sub-streams to transmit data. However, the existing multi-path transmission protocol does not allocate data between multiple sub-flows from the perspective of shaping network traffic. Design.

Summary of the invention

Embodiments of the present invention provide a method and apparatus for transmitting data, which can dynamically adjust the number of substreams in a communication connection, and improve network utilization and transmission efficiency.

In a first aspect, a method for transmitting data is provided, where a communication connection of a network system to which the method is applied currently includes n sub-streams, the method comprising:

Determining to create an n+1th substream according to a load strength of the current n substreams in the communication connection, where n is a positive integer;

Transmitting the first data packet to be sent on the (n+1)th substream.

With the first aspect, in a first possible implementation manner of the first aspect, the determining, according to the load strength of the current n substreams in the communication connection, determining to create the (n+1)th substream includes:

After acquiring the first data packet, determining to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the determining, according to the load strength of the current n substreams in the communication connection, determining to create the (n+1)th substream includes:

The load strength of the current n substreams in the communication connection is detected according to a preset first period, and the n+1th substream is determined to be created according to the load strength of the n substreams.

With reference to the first aspect and any one of the possible implementations of the first to the second possible implementations of the first aspect, in a third possible implementation of the first aspect, the substream is a base The sub-stream of the transmission control protocol TCP, the determining, according to the load strength of the n sub-streams, the creation of the (n+1)th sub-stream, including:

Determining that there is no substream in the n substreams whose load strength is less than a preset first threshold and having an available transmission window;

It is determined that the n+1th substream is created.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation of the first aspect, before the determining to create the (n+1)th substream, the method further includes:

Determining that the current number of substreams n in the communication connection is less than a preset maximum number of substreams m, where m is a positive integer.

In conjunction with the third or fourth possible implementation of the first aspect, in a fifth possible implementation of the first aspect, the method further includes:

Determining that there is a substream in the current substream of the communication connection that has a load strength less than the first threshold and has an available transmission window;

Sending a second data packet to be transmitted on the determined substream.

With reference to the first aspect, and any one of the first to the fifth possible implementation manners of the first aspect, in a sixth possible implementation manner of the first aspect, the method further includes:

When the first data packet is transmitted, the load strength of the (n+1)th substream is updated.

With reference to the first aspect, and any one of the first to the sixth possible implementation manners of the first aspect, in a seventh possible implementation manner of the first aspect, the method further includes:

Determining, according to a preset second period, whether there is a substream that needs to be destroyed in the current substream of the communication connection;

When there is a substream that needs to be destroyed, the substream that needs to be destroyed is destroyed.

In conjunction with the seventh possible implementation of the first aspect, in an eighth possible implementation manner of the first aspect, the determining, by the preset second period, whether the current substream of the communication connection needs to be destroyed Subflows, including:

Determining, according to the second period, the number p of current substreams of the communication connection, where p is a positive integer;

Determining the load strength of each of the p substreams when p is greater than or equal to 2;

Determining the q substreams satisfying the preset condition as substreams to be destroyed, where q is less than p An integer of the preset condition that the load strength of the substream is less than a preset second threshold.

In conjunction with the seventh possible implementation of the first aspect, in a ninth possible implementation manner of the first aspect, the determining, by the preset second period, whether the current substream of the communication connection needs to be destroyed Subflows, including:

Determining, according to the second period, the number p of current communication streams of the communication connection, where p is a positive integer;

A substream having the smallest load intensity among the p substreams is determined as a substream that needs to be destroyed.

With reference to any one of the possible implementations of the fourth to the ninth possible implementations of the first aspect, in a tenth possible implementation manner of the first aspect, the method further includes:

When the communication connection is established, s substreams are created, where s is a positive integer greater than or equal to 1, and s is less than the maximum number of substreams m.

With reference to the first aspect and any one of the first to the tenth possible implementation manners of the first aspect, in an eleventh possible implementation manner of the first aspect, the load strength is The normalized throughput rate, which is the amount of data transmitted by the substream in unit time over the unit network interface bandwidth.

A second aspect provides an apparatus for transmitting data, where a communication connection of a network system to which the apparatus belongs currently includes n substreams, and the apparatus includes:

a first determining unit, configured to determine to create an n+1th substream according to a load strength of the current n substreams in the communication connection, where n is a positive integer;

a first sending unit, configured to send, on the n+1th substream determined on the first determining unit, the first data packet to be sent.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the first determining unit is specifically configured to:

With reference to the second aspect, in a second possible implementation manner of the second aspect, the first determining unit is specifically configured to:

Combining the second aspect with any of the first to second possible implementations of the second aspect In a third possible implementation manner of the second aspect, the sub-flow is a sub-flow based on a transmission control protocol (TCP), where the first determining unit is specifically configured to:

It is determined that the n+1th substream is created.

In conjunction with the third possible implementation of the second aspect, in a fourth possible implementation of the second aspect, before determining to create the (n+1)th substream, the first determining unit is further configured to:

In conjunction with the third or fourth possible implementation of the second aspect, in a fifth possible implementation of the second aspect, the device further includes:

a second determining unit, configured to determine that there is a substream in the current substream of the communication connection that has a load strength less than the first threshold and has an available transmission window;

a second sending unit, configured to send, on the substream determined by the second determining unit, a second data packet to be sent.

With reference to the second aspect, and any one of the first to the fifth possible implementation manners of the second aspect, in a sixth possible implementation manner of the second aspect, the device further includes:

And an updating unit, configured to update a load strength of the (n+1)th substream when the first data packet is transmitted.

With reference to the second aspect, and any one of the first to the sixth possible implementation manners of the second aspect, in a seventh possible implementation manner of the second aspect, the device further includes:

a third determining unit, configured to determine, according to a preset second period, whether a substream that needs to be destroyed exists in a current substream of the communication connection;

The destruction unit is configured to destroy the substream that needs to be destroyed when there is a substream that needs to be destroyed.

In conjunction with the seventh possible implementation of the second aspect, in the eighth possible implementation of the second aspect, the third determining unit is specifically configured to:

The q substreams satisfying the preset condition are determined as substreams to be destroyed, wherein q is an integer smaller than p, and the preset condition includes that the load strength of the substream is less than a preset second threshold.

With reference to the seventh possible implementation of the second aspect, in a ninth possible implementation manner of the second aspect, the third determining unit is specifically configured to:

With reference to any one of the possible implementations of the fourth to the ninth possible implementations of the second aspect, in a tenth possible implementation manner of the second aspect, the device further includes:

a creating unit, configured to create s substreams when the communication connection is established, where s is a positive integer greater than or equal to 1, and s is less than the maximum number of substreams m.

With reference to the second aspect and any one of the first to the tenth possible implementation manners of the second aspect, in the eleventh possible implementation manner of the second aspect, the load strength is The normalized throughput rate, which is the amount of data transmitted by the substream in unit time over the unit network interface bandwidth.

In a third aspect, a network system is provided, comprising the apparatus for transmitting data according to any one of the implementations of the second aspect.

Based on the foregoing technical features, the method and apparatus for transmitting data according to the embodiment of the present invention determines that a new substream is created according to the load strength of the current substream of the communication connection, and the data packet is sent on the newly created substream, and the communication can be dynamically adjusted. The number of substreams in the connection, and balance the load strength between the substreams, improving network utilization and transmission efficiency.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative work.

1 is a schematic flow chart of a method of transmitting data according to an embodiment of the present invention.

2 is a schematic flow chart of a method of transmitting data according to another embodiment of the present invention.

FIG. 3 is a schematic flowchart of a method for transmitting data according to still another embodiment of the present invention.

4 is a schematic block diagram of an apparatus for transmitting data according to an embodiment of the present invention.

FIG. 5 is a schematic block diagram of an apparatus for transmitting data 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 a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

This article first briefly introduces the existing related technology MPTCP. MPTCP is currently the most representative and promising transport layer multipath transport protocol. MPTCP performs parallel transmission of data using multiple substreams. Each sub-flow is similar to the traditional TCP, with its own transmission queue, transmission window (congestion window), sequence number space; sub-flow uses independent congestion control mechanism or sub-stream coupling congestion control mechanism; all sub-streams are sent The host side shares the transmission buffer maintenance total transmission window, records the receiving window notified by the receiving end, all sub-streams share the receiving buffer on the receiving host side, maintain the total receiving window, and a set of outer sequence number space can guarantee transmission and reception. The order of the data in the buffer.

The data transmission process of the MPTCP communication connection is: the data is obtained from the transmission buffer at the transmitting host end, and the data packet is distributed to each sub-flow for transmission according to the corresponding sub-stream data distribution mechanism; the data of each sub-flow is in accordance with the respective The sequence number is numbered and transmitted in a sequence, potentially flowing through different network paths, and finally to the receiving host; on the receiving host, multiple substreams are received and recombined into one data stream, which is placed in the receiving buffer.

In MPTCP, the number of substreams is already determined when establishing a communication connection, and is fixed during the lifetime of the communication connection and cannot be dynamically adjusted. At present, the number of substreams of the MPTCP communication connection is specified by configuring the system parameter "net.mptcp.mptcp_path_manager" of the MPTCP. This leads to MPTCP not being able to weigh the advantages and disadvantages of multiple substreams and optimize transmission performance. At the same time, the use of a fixed number of substreams is also disadvantageous for smoothing the fluctuation of the communication load and providing the transmission capability of dynamic scaling.

In addition, the current MPTCP provides two sub-stream data distribution mechanisms: one is the minimum RTT-first mechanism, that is, the data is preferentially scheduled to the smallest sub-stream of the RTT; the other is the Round-Robin mechanism, that is, at all The data is rotated on the substream. Which sub-stream data distribution mechanism is used can be specified by configuring the system parameter "net.mptcp.mptcp_scheduler" of MPTCP. These sub-stream data distribution mechanisms do not consider shaping the characteristics of sub-flow traffic, sub-flow traffic It is easy to fluctuate with the strength of the communication load, is not stable, and the throughput between substreams may also vary greatly, which will bring difficulties to network load balancing.

The present invention is directed to improvements in the above-described problems in the transport layer multipath transmission protocol represented by MPTCP. 1 illustrates a method 100 of transmitting data, which is performed by a device that transmits data in a communication connection, and in particular, by a sub-flow control mechanism and a module corresponding to a sub-stream data distribution mechanism, in accordance with an embodiment of the present invention. The communication connection of the network system of the application method 100 currently includes n sub-streams, and the method 100 includes:

S101. Determine, according to the current load strength of the n substreams in the communication connection, that the n+1th substream is created, where n is a positive integer.

S102. Send a first data packet to be sent on the (n+1)th substream.

Specifically, with respect to the existing data transmission mechanism, the embodiment of the present invention controls the allocation of data between substreams by considering the load strength of the substream. Moreover, in order to match the aggregate transmission capacity of the communication load and the substream, and smooth the fluctuation of the communication load, the substream number is managed by the load adaptive subflow control technique. When the load strength of the current substream of the communication connection rises, a new substream can be created according to a preset rule to increase the transmission capability. When there is a data packet to be transmitted, for example, the first data packet, the apparatus for transmitting data according to the embodiment of the present invention determines that the load of the n substreams in the communication connection is too high according to the load strength of the n substreams in the communication connection. Determining to create an n+1th substream to transmit the first data packet on the (n+1)th substream.

It should be understood that, in the embodiment of the present invention, after acquiring the first data packet to be sent, determining, according to the load strength of the current n substreams in the communication connection, determining to create the (n+1)th substream; or according to a certain period. The load strength of the current n substreams in the communication connection is detected, and then the n+1th substream is determined to be created. That is, the embodiment of the present invention does not limit the foregoing, after the first data packet to be sent is obtained, and the first data packet to be sent is obtained.

In another aspect, the embodiment of the present invention provides a communication load adaptive sub-flow control method and a sub-stream data distribution mechanism, and the combination of the two mechanisms can solve the sub-flow number unadjustable and sub-flow in the existing multi-path transmission protocol. Traffic shaping is poor.

Therefore, the method for transmitting data according to the embodiment of the present invention determines that a new substream is created according to the load strength of the current substream of the communication connection, and the data packet is sent on the newly created substream, and the substream in the communication connection can be dynamically adjusted. Count and balance the load strength between substreams to improve network utilization and transmission efficiency.

Optionally, as an embodiment, S101 is based on the negative of the current n substreams in the communication connection. Load strength, determine the creation of the n+1th substream, including:

Specifically, whenever there is a new data packet to be transmitted, the load strength of the current n substreams in the communication connection is detected. When the load strength of the current substream of the communication connection is strong (for example, when the load strength of all current substreams is greater than a preset threshold), a new substream may be created according to a preset rule to increase the transmission capability. That is, when there is a first data packet to be transmitted, the load strength of the current n substreams in the communication connection is detected, and when the transmission capability of the current n substreams in the communication connection is insufficient, a new n+1th substream is created. Transmitting the first data packet to be transmitted on the (n+1)th substream.

Optionally, as an embodiment, S101 determines to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection, including:

Specifically, the load strength of the current n substreams in the communication connection is detected according to a first period preset by the system. When the load strength of the current substream of the communication connection is strong (for example, when the load strength of all current substreams is greater than a preset threshold), a new substream may be created according to a preset rule to increase the transmission capability. That is, when the transmission capacity of the current n substreams in the communication connection is insufficient, a new n+1th substream is created. When there is a first data packet to be transmitted, one sub-flow is selected from the sub-streams in the communication connection to send the first data packet to be transmitted. Preferably, the newly created n+1th substream in the communication connection is selected to send the first data packet to be sent.

Optionally, in the embodiment of the present invention, the sub-flow is a sub-flow based on the transmission control protocol (TCP), and S102 determines to create the (n+1)th sub-stream according to the load strength of the n sub-streams, including:

Make sure to create the n+1th substream.

Specifically, for a substream having a transmission window concept, such as a TCP-based substream, whether data can be transmitted on the substream, on which substream the data is transmitted, whether a new substream needs to be created, in addition to considering the substream Load strength, you can also consider whether the substream currently has an available send window (ie, the send window is not full). Therefore, in the embodiment of the present invention, when performing sub-stream data distribution, it is further considered whether the sub-stream currently has an available transmission window. When there is no sub-flow with a load strength less than the preset first threshold and the available transmission window is in the communication connection, a new sub-flow is created. among them, The first threshold may be determined according to the load capacity of the sub-flow, and the different sub-flows may be corresponding to different first thresholds. For the sake of simplicity, the same first threshold may be preset for different sub-flows. limited.

For a substream of a multipath transmission protocol that does not have a transmission window concept, such as a User Datagram Protocol (UDP) based substream, embodiments of the present invention do not consider whether there is a factor of available transmission window. Alternatively, it can be considered that its send window is infinite, that is, it always has an available send window.

Optionally, in the embodiment of the present invention, before determining to create the (n+1)th substream, the method 100 further includes:

It is determined that the current number of substreams n in the communication connection is less than a preset maximum number of substreams m, where m is a positive integer.

Specifically, the embodiment of the present invention allows a new substream to be created when the load strength of the current substream in the communication connection is large, or when the current substream does not exist, and the data packet cannot be sent. The packet is transmitted on the substream. In the embodiment of the present invention, in order to avoid an infinite growth of the substream, the maximum number of substreams may be preset to be m. The maximum number of substreams m can be specified in advance by an artificial configuration. It should be understood that the current sub-flow in the communication connection of the embodiment of the present invention may be a TCP-based sub-flow, or may be a sub-flow based on UDP or other protocols, which is not limited by the embodiment of the present invention.

In order to fully utilize the transmission capability of the network, the embodiment of the present invention may further allow: when the number of substreams in the communication link reaches the maximum number of substreams m, and the load strengths of all substreams having available transmission windows have reached the preset value. At the first threshold, the substream may send more data than the first threshold.

Optionally, as an embodiment, the method 100 further includes:

Determining that there is a substream in the current substream of the communication connection that has a load strength less than the first threshold and having an available transmission window;

Sending a second data packet to be sent on the determined substream.

Specifically, in the embodiment of the present invention, for the second data packet, when there is a sub-flow in the communication connection whose load strength is less than the first threshold and has an available transmission window, the first packet may be sent on the determined sub-flow. Two packets. For example, the second data packet may be sent on a substream whose detected first load strength is less than a first threshold and has an available transmission window; and the detected multiple load strengths may be less than a first threshold, and have The second data packet is sent by using a sub-stream with the smallest load strength, and the specific implementation manner is not limited in the embodiment of the present invention. Preferably, the detected load strength may be less than the first threshold in a round robin manner, and And transmitting the second data packet on the first substream having an available transmission window.

The embodiment of the present invention can provide better transmission performance by creating a new substream at a high load, and by limiting the load strength of each substream, it can shape good traffic to optimize the overall transmission efficiency of the network. The embodiment of the present invention, especially when combined with a low load, can reduce the number of substreams, and can control the number of substreams within a suitable range, so that the number of substreams can satisfy the load requirement of the communication connection. On the other hand, the overhead required to maintain the substream can be balanced with the load requirements, so that the communication system has high transmission performance.

Optionally, in the embodiment of the present invention, the load strength is a normalized throughput rate, and the normalized throughput rate is a data volume transmitted by the sub-flow in a unit time and a unit network interface bandwidth.

Specifically, in the embodiment of the present invention, the normalized throughput rate of the substream can be used to characterize the load strength of the substream, and the small stream characteristic of the substream can be ensured by controlling the load strength of the substream. The normalized throughput rate is the amount of data transmitted by the substream in unit time over the unit network interface bandwidth. When the normalized throughput rate of the substream is used to characterize the load strength of the substream, the normalized throughput rate of the substream can be statistically obtained by periodically dividing the lifetime of the communication connection, for example, dividing the lifetime into several A time slice of equal length. The amount of data that has been sent by the substream in each time slice is independently counted, and the amount of data is divided by the entire time slice length to obtain the current on-chip average throughput rate. In order to facilitate setting and comparing the first threshold, the throughput rate is generally further expressed as a normalized form, ie, the throughput rate is divided by the network interface bandwidth to obtain a value between 0 and 1, as a normalized throughput rate. It should be noted that the length of the time slice here can be specified by the artificial configuration. Generally, the value should be able to tolerate unequal bursts of several to dozens of data packets, so as to avoid the throughput value for the communication load. The short-term fluctuations are too sensitive.

The specific calculation of the normalized throughput rate of the substream can be exemplified as follows: assuming that the time slice length is L, the amount of data that the substream i has sent in the current time slice is C _i , and the network interface bandwidth is B _i , then the substream i The normalized throughput rate R _i is C _i /(L × B _i ). It should be noted that the normalized throughput rate of the substream is only one way to measure the load strength of the substream, and the embodiment of the present invention allows other indicators to be used to characterize the load strength of the substream to be replaced.

Optionally, in the embodiment of the present invention, the method 100 further includes:

When the transmission of the first data packet is completed, the load strength of the (n+1)th substream is updated.

Specifically, when the first data packet is transmitted on the newly created n+1th substream, the load strength of the (n+1)th substream is updated, so that before the next data packet to be transmitted is allocated. The substream for transmitting the data packet is determined according to the load strength of each substream. Taking the load strength as the normalized throughput rate, the substream j updates its statistical value of the amount of data transmitted on the current time slice after the data packet is transmitted, C _j =C _j '+Pkt_Len; the substream j is transmitted in the data packet. After completion, update its normalized throughput rate on the current time slice R _j =C _j /(L×B _j ), where C _j ' is the amount of data transmitted by the sub-stream j before the data packet is transmitted on the current time slice. , Pkt_Len is the amount of data of the packet.

It should be understood that the load strength of each substream may be stored in a memory of the network system or in a storage unit to which the substream control mechanism and/or the inter-stream data distribution mechanism can read and write. When the first data packet transmission is completed, the corresponding module of the sub-flow control mechanism and/or the sub-stream data distribution mechanism calculates a new load strength and updates the newly calculated load strength to the above-mentioned memory or storage unit. When there is a new data packet to be transmitted, or when a predetermined first period arrives to determine whether a newly created substream needs to be newly created, the subflow control mechanism and/or the corresponding module of the substream interflow data distribution mechanism are The load strength of each substream is read in a memory or storage unit for use.

It should also be understood that in the embodiment of the present invention, not only the (n+1)th substream is updated in its load strength after the data packet is transmitted. When there are data packets sent on other sub-flows in the communication connection, the load strength of the sub-flow should be updated after the transmission is completed to ensure the accuracy of the load strength of each sub-flow, and it is convenient to determine according to the load strength of each sub-flow. Whether you need to create a new subflow or destroy some substreams, and assign the next packet to be sent. In addition, in the solution of the embodiment of the present invention, the load strength of each substream in the communication connection may be updated according to a period (for example, according to a time slice) to ensure the accuracy of the load strength of each substream when the data packet is distributed.

Specifically, when the communication connection of the transport layer multipath protocol is established, one or a specified number of s initial substreams are created. When the current substream load strength is large, or when the current substream does not exist, the available transmission window cannot transmit the data packet, a new substream is created, and the data packet is transmitted on the new substream. It can provide better transmission performance and optimize the overall transmission efficiency of the network.

Determining, according to a preset second period, whether there is a substream to be destroyed in the current substream of the communication connection;

Specifically, the embodiment of the present invention may determine, according to a preset second period (for example, at the end of each time slice), whether there is a need to destroy the current substream of the communication connection according to a preset rule. Subflow. The first period and the second period in the embodiment of the present invention may be the same or different. That is, the creation and destruction of the sub-flows may be performed in the same period or in different periods, which is not limited in the embodiment of the present invention. For example, the embodiment of the present invention can determine the substream to be destroyed according to the load strength of each substream (for example, the normalized throughput rate). The embodiment of the present invention may determine, according to other attributes of the communication connection, such as the round trip time RRT of the data transmission, whether there is a substream that needs to be destroyed in the current substream, and when there is a substream that needs to be destroyed, destroy the substream that needs to be destroyed, The embodiment of the invention is not limited thereto.

It should be understood that, in the embodiment of the present invention, after determining the substream that needs to be destroyed, the substream destruction may be performed after waiting for a certain time. For example, the substream can be destroyed after waiting for the data on the substream to be destroyed to be transferred. Alternatively, after the substream is destroyed, the data originally transmitted on the substream is transferred to other substreams for transmission. Other measures may be taken to ensure that the data transmission task can be completed normally, which is not limited by the embodiment of the present invention.

Optionally, in the embodiment of the present invention, determining, according to the preset second period, whether there is a substream that needs to be destroyed in the current substream of the communication connection, including:

Specifically, the specific method for determining whether there is a substream to be destroyed in the current substream of the communication connection may be as follows: determining the current substream of the communication connection according to a preset second period (eg, at the end of each time slice) The quantity p; when p is greater than or equal to 2, determining the load strength of each of the p substreams, that is, when more than one substream is included in the communication connection, performing the process of determining the substreams to be destroyed, when When the number of substreams is 1, regardless of the load strength of the substream, the substream is retained, that is, at least one available substream is always maintained; and q substreams whose load strength is less than a preset second threshold are determined to be destroyed. The substream, that is, the q substreams with less load strength in the p current substreams are determined as substreams to be destroyed. The second threshold may be determined according to the load capacity of the sub-flow, and the different sub-flows may be corresponding to different second thresholds. For the sake of simplicity, the same second threshold may be preset for different sub-flows. This is not limited. The second threshold should be less than the first threshold according to an embodiment of the invention, so the second threshold can be determined according to the first threshold, for example, the second threshold can be a first threshold multiplied by a constant θ, θ being greater than zero and less than one.

Preferably, in the embodiment of the present invention, determining, according to the preset second period, whether there is a substream to be destroyed in the current substream of the communication connection, including:

The substream having the smallest load strength among the p substreams is determined as the substream to be destroyed.

Specifically, in the embodiment of the present invention, according to the preset second period, when the current number of substreams is greater than or equal to 2, each substream is destroyed, and the load intensity of the p current substreams is minimized. Stream destruction.

A method for transmitting data according to an embodiment of the present invention is described below with a specific example. This example mainly describes the perspective of a data distribution mechanism between sub-streams. 2 illustrates a method 200 of transmitting data in accordance with another embodiment of the present invention. The method 200 can be performed by a module corresponding to a sub-stream data distribution mechanism. The current transport layer multipath protocol communication connection establishment includes n substreams. When the data packet to be transmitted needs to be transmitted, the module corresponding to the inter-stream data distribution mechanism performs S201 to S208 to determine that one substream transmits the data packet, and when there are multiple data packets to be transmitted, S201 to S208 are repeatedly executed. The method 200 specifically includes:

S201. Acquire a data packet to be sent.

S202. Determine whether there is a substream F _A that satisfies the condition. Wherein, the substream F _A is a first substream v having a normalized throughput rate less than a first threshold (R _v <R _th ) detected by the round robin method and having an available transmission window. If yes, execute S203; if not, execute S204.

S203. Send a data packet on the sub-flow F _A , and update a statistical value (C _v = C _v '+Pkt_Len) and a normalized throughput rate (R _v ) of the data volume sent by the sub-flow v=F _A in the current time slice. =C _v /(L × B _v )), and then S208 is performed.

S204. Determine whether the current number of substreams is less than the maximum number of substreams m. If yes, execute S205; if no, execute S206.

S205, notifies the sub-flow control mechanism module corresponding to a newly created sub-stream F _New, and transmits the data packet on the F _New sub newly created stream while updating the sub-stream v = F _New send statistic data amount in the current time slot (C _v = C _v '+Pkt_Len) and the normalized throughput rate (R _v = C _v / (L × B _v )), and then S208 is performed.

S206. Determine whether there is a substream F _B that satisfies the condition. The substream F _B is a first substream v having a normalized throughput rate greater than or equal to a first threshold (R _v ≥R _th ) detected by the method of rotation and having an available transmission window. If yes, execute S207. If not, the current round does not send a data packet, and S208 is performed.

S207. Send a data packet on the substream F _B , and update a statistical value (C _v = C _v '+Pkt_Len) and a normalized throughput rate (R _v ) of the data volume sent by the substream v=F _B in the current time slice. =C _v /(L×B _v )).

S208, the processing ends.

FIG. 3 illustrates a method 300 for transmitting data according to still another embodiment of the present invention. The method 300 may be performed by a module corresponding to a sub-flow control mechanism, and is mainly described from the perspective of a sub-flow control mechanism. The module corresponding to the sub-flow control mechanism creates s initial sub-flows when the communication connection is established, where s is greater than or equal to 1; and when receiving the notification of creating a new sub-flow sent by the sub-flow management module, creating a New subflow. At the end of each time slice, the subflow management module also determines whether to destroy the subflow according to the following steps included in method 300:

S301. Determine whether the current sub-flow number p is greater than or equal to 2: if yes, execute S302; if not, execute S304 to end processing.

S302, determining whether there is a substream, is always available in a plurality of time slices (for example, K time slices), and the normalized throughput rate is less than a second threshold θ×R _th (0<θ<1); if yes, Go to S303; if no, execute S304 to end the process. Where K is a configurable time slice constant, such as K = 10; θ is a configurable constant between 0 and 1, such as θ = 0.5.

S303. Destroy the substream that has the smallest throughput rate in the substream that satisfies the condition of S302.

S304, the processing ends.

It should be understood that, in various embodiments of the present invention, the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be taken to the embodiments of the present invention. The implementation process constitutes any limitation.

Embodiments of the present invention control the allocation of data between substreams by combining a normalized throughput rate constraint and a rotation mechanism—controlling the amount of data transmitted by each substream in a unit time so that the normalized throughput rate does not exceed Specify thresholds and distribute data in a round-robin fashion across all subflows where the normalized throughput does not reach the specified threshold—to shape the small stream flow characteristics. Moreover, in order to match the aggregate transmission capacity of the communication load and the substream, and smooth the fluctuation of the communication load, the number of substreams is managed by the load adaptive subflow control technique. When the communication load rises and the existing substream cannot transmit more data due to reaching the threshold of the normalized throughput rate, a new substream is created to increase the transmission capability; when the communication load is decreased, the existing substream transmission capability is insufficient. When used, destroy sub-flows with poor performance.

The sub-flow control mechanism and the inter-stream data distribution mechanism proposed by the embodiments of the present invention are used to perform data distribution and creation and destruction of sub-streams. Subflow control mechanism and substream interflow data distribution mechanism can be The implementation of the corresponding module is also implemented by a unified management module or device, which is not limited by the embodiment of the present invention.

In the method for transmitting data according to the embodiment of the present invention, the number of substreams can be dynamically adjusted according to the load strength, realizing dynamic expansion and contraction of communication capabilities, and shaping traffic with smooth small substream characteristics. Compared with the existing MPTCP, the number of substreams can be greatly reduced at a low load, the transmission efficiency is better than MPTCP at a high load, and the overall transmission of the network is optimized by shaping the traffic. effectiveness. The embodiment of the present invention can increase the communication load strength adaptive sub-flow adjustment capability, and on the one hand, the number of small-sized data communication that is dominant can be used much less than the current sub-flow number setting value of the existing multi-path transmission protocol. The number of substreams, thereby substantially reducing the substream cost described above; on the other hand, for large data traffic, it is still possible to provide sufficient transmission capability using more substreams.

Therefore, the method for transmitting data according to the embodiment of the present invention determines a substream for transmitting a data packet according to a load strength of a current substream of the communication connection, where the substream is a current substream of the communication connection or a newly created substream. Transmitting data packets on the substream enables dynamic adjustment of the number of substreams in the communication link and equalizes the load strength between the substreams, thereby improving network utilization and transmission efficiency.

The method of transmitting data according to an embodiment of the present invention is described in detail above with reference to FIGS. 1 through 3, and an apparatus for transmitting data according to an embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

FIG. 4 illustrates an apparatus 400 for transmitting data in accordance with an embodiment of the present invention. The communication connection of the network system to which the device 400 belongs currently includes n substreams. As shown in FIG. 4, the apparatus 400 includes:

The first determining unit 401 is configured to determine, according to the current load strength of the n substreams in the communication connection, that the n+1th substream is created, where n is a positive integer;

The first sending unit 402 is configured to send the first data packet to be sent on the n+1th substream determined by the first determining unit 401.

Therefore, the apparatus for transmitting data according to the embodiment of the present invention determines to create a new substream according to the load strength of the current substream of the communication connection, and sends a data packet on the newly created substream, so that the substream in the communication connection can be dynamically adjusted. Count and balance the load strength between substreams to improve network utilization and transmission efficiency.

In the embodiment of the present invention, the first determining unit 401 is specifically configured to:

In the embodiment of the present invention, the sub-flow is a sub-flow based on the transmission control protocol TCP, and the first determining unit 401 is specifically configured to:

Make sure to create the n+1th substream.

In the embodiment of the present invention, optionally, before determining to create the (n+1)th substream, the first determining unit 401 is further configured to:

In the embodiment of the present invention, optionally, the device 400 further includes:

And a second sending unit, configured to send, on the substream determined by the second determining unit, the second data packet to be sent.

a third determining unit, configured to determine, according to the preset second period, whether there is a substream that needs to be destroyed in the current substream of the communication connection;

In the embodiment of the present invention, optionally, the third determining unit is specifically configured to:

According to the second period, the number p of current substreams of the communication connection is determined, where p is a positive integer number;

In the embodiment of the present invention, optionally, the load strength is a normalized throughput rate, and the normalized throughput rate is the amount of data transmitted by the sub-flow in a unit time and the unit network interface bandwidth.

It should be understood that apparatus 400 in accordance with embodiments of the present invention may correspond to an executing body in an embodiment of the method of the present invention, and that the above and other operations and/or functions of the various modules in apparatus 400 are respectively implemented in order to achieve the operations of FIGS. 1 through 3. The corresponding processes of the various methods are not described here for brevity.

Therefore, the apparatus for transmitting data according to the embodiment of the present invention determines a substream for transmitting a data packet according to a load strength of a current substream of the communication connection, where the substream is a current substream of the communication connection or a newly created substream. Transmitting data packets on the substream enables dynamic adjustment of the number of substreams in the communication link and equalizes the load strength between the substreams, thereby improving network utilization and transmission efficiency.

As shown in FIG. 5, an embodiment of the present invention further provides an apparatus 500 for transmitting data, where a communication connection of a network system to which the apparatus 500 belongs currently includes n substreams. The apparatus 500 includes a processor 501, a memory 502, a bus system 503, and a transceiver 504. The processor 501, the memory 502 and the transceiver 504 are connected by a bus system 503 for storing instructions for executing the instructions stored by the memory 502 to control the transceiver 504 to send or receive signals. among them,

The processor 501 is configured to: determine to create an n+1th substream according to a load strength of the current n substreams in the communication connection, where n is a positive integer;

The transceiver 504 is configured to: send the first data packet to be sent on the (n+1)th substream.

It should be understood that, in the embodiment of the present invention, the processor 501 may be a central processing unit ("CPU"), and the processor 501 may also be other general-purpose processors, digital signal processors (DSPs). , application specific integrated circuit (ASIC), off-the-shelf programmable gate array (FPGA) Or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, and the like. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like.

The memory 502 can include read only memory and random access memory and provides instructions and data to the processor 501. A portion of the memory 502 can also include a non-volatile random access memory. For example, the memory 502 can also store information of the device type.

The bus system 503 may include a power bus, a control bus, a status signal bus, and the like in addition to the data bus. However, for clarity of description, various buses are labeled as bus system 503 in the figure.

In the implementation process, each step of the foregoing method may be completed by an integrated logic circuit of hardware in the processor 501 or an instruction in a form of software. The steps of the method disclosed in the embodiments of the present invention may be directly implemented as a hardware processor, or may be performed by a combination of hardware and software modules in the processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory 502, and the processor 501 reads the information in the memory 502 and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

Optionally, as an embodiment, the processor 501 determines to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection, including:

Optionally, as an embodiment, the sub-flow is a sub-flow based on the Transmission Control Protocol (TCP), and the processor 501 determines, according to the load strength of the n sub-streams, the creation of the (n+1)th sub-stream, including:

Make sure to create the n+1th substream.

Optionally, as an embodiment, before determining to create the (n+1)th substream, the processor 501 is further configured to:

Optionally, as an embodiment, the processor 501 is further configured to: determine that there is a substream in the current substream of the communication connection that has a load strength less than the first threshold and has an available send window;

The transceiver 504 is further configured to: send the second data packet to be sent on the determined substream.

Optionally, as an embodiment, the processor 501 is further configured to: when the first data packet is transmitted, update a load strength of the (n+1)th substream.

Optionally, as an embodiment, the processor 501 is further configured to:

When there is a subflow that needs to be destroyed, destroy the subflow that needs to be destroyed.

Optionally, as an embodiment, the processor 501 determines, according to the preset second period, whether there is a substream that needs to be destroyed in the current substream of the communication connection, including:

Optionally, as an embodiment, the processor 501 is further configured to:

Optionally, as an embodiment, the load strength is a normalized throughput rate, and the normalized throughput rate is the amount of data transmitted by the sub-flow in a unit time on a unit network interface bandwidth.

It should be understood that the apparatus 500 for transmitting data according to an embodiment of the present invention may correspond to the apparatus 400 in the embodiment of the present invention, and may correspond to a corresponding body in the method according to an embodiment of the present invention, and each module in the apparatus 500 The above and other operations and/or functions are respectively implemented in order to implement Figure 1 The corresponding processes of the respective methods in FIG. 3 are not described herein again for the sake of brevity.

The embodiment of the present invention further provides a network system, including the device 400 or the device 500 for transmitting data described in the embodiment of the present invention. Specifically, the switching device in the network system may be the device 400 or the device 500 for transmitting data according to an embodiment of the present invention.

It should be understood that in the embodiment of the present invention, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B from A does not mean that B is only determined based on A, and that B can also be determined based on A and/or other information.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in various embodiments of the present invention may be integrated in one processing unit In addition, each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

The above is only a 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 protection of the present invention should be determined by the scope of the claims.

Claims

A method for transmitting data, characterized in that a communication connection of a network system to which the method is applied currently includes n sub-streams, the method comprising:

Determining to create an n+1th substream according to a load strength of the current n substreams in the communication connection, where n is a positive integer;

Transmitting the first data packet to be sent on the (n+1)th substream.
The method according to claim 1, wherein the determining to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection comprises:

After acquiring the first data packet, determining to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection.
The method according to claim 1, wherein the determining to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection comprises:

The load strength of the current n substreams in the communication connection is detected according to a preset first period, and the n+1th substream is determined to be created according to the load strength of the n substreams.
The method according to any one of claims 1 to 3, wherein the substream is a subflow based on a Transmission Control Protocol (TCP), and the determining is based on a load strength of the n substreams to create an n+th 1 substream, including:

Determining that there is no substream in the n substreams whose load strength is less than a preset first threshold and having an available transmission window;

It is determined that the n+1th substream is created.
The method according to claim 4, wherein before the determining to create the (n+1)th substream, the method further comprises:

Determining that the current number of substreams n in the communication connection is less than a preset maximum number of substreams m, where m is a positive integer.
The method according to claim 4 or 5, wherein the method further comprises:

Determining that there is a substream in the current substream of the communication connection that has a load strength less than the first threshold and has an available transmission window;

Sending a second data packet to be transmitted on the determined substream.
The method according to any one of claims 1 to 6, wherein the method further comprises:

When the first data packet is transmitted, the load strength of the (n+1)th substream is updated.
The method according to any one of claims 1 to 7, wherein the method further comprises:

Determining, according to a preset second period, whether there is a substream that needs to be destroyed in the current substream of the communication connection;

When there is a substream that needs to be destroyed, the substream that needs to be destroyed is destroyed.
The method according to claim 8, wherein the determining, according to the preset second period, whether there is a substream to be destroyed in the current substream of the communication connection comprises:

Determining, according to the second period, the number p of current substreams of the communication connection, where p is a positive integer;

Determining the load strength of each of the p substreams when p is greater than or equal to 2;

The q substreams satisfying the preset condition are determined as substreams to be destroyed, wherein q is an integer smaller than p, and the preset condition includes that the load strength of the substream is less than a preset second threshold.
The method according to claim 8, wherein the determining, according to the preset second period, whether there is a substream to be destroyed in the current substream of the communication connection comprises:

Determining, according to the second period, the number p of current communication streams of the communication connection, where p is a positive integer;

Determining the load strength of each of the p substreams when p is greater than or equal to 2;

A substream having the smallest load intensity among the p substreams is determined as a substream that needs to be destroyed.
The method according to any one of claims 5 to 10, wherein the method further comprises:

When the communication connection is established, s substreams are created, where s is a positive integer greater than or equal to 1, and s is less than the maximum number of substreams m.
The method according to any one of claims 1 to 11, wherein the load strength is a normalized throughput rate, and the normalized throughput rate is a sub-flow in a unit time, on a unit network interface bandwidth. The amount of data transferred.
An apparatus for transmitting data, characterized in that a communication connection of a network system to which the apparatus belongs currently includes n substreams, and the apparatus includes:

a first determining unit, configured to determine to create an n+1th substream according to a load strength of the current n substreams in the communication connection, where n is a positive integer;

a first sending unit, configured to send, on the n+1th substream determined on the first determining unit, the first data packet to be sent.
The device according to claim 13, wherein the first determining unit is specifically configured to:

After acquiring the first data packet, determining to create the (n+1)th substream according to the load strength of the current n substreams in the communication connection.
The device according to claim 13, wherein the first determining unit is specifically configured to:

The load strength of the current n substreams in the communication connection is detected according to a preset first period, and the n+1th substream is determined to be created according to the load strength of the n substreams.
The device according to any one of claims 13 to 15, wherein the sub-flow is a sub-flow based on a Transmission Control Protocol (TCP), and the first determining unit is specifically configured to:

Determining that there is no substream in the n substreams whose load strength is less than a preset first threshold and having an available transmission window;

It is determined that the n+1th substream is created.
The apparatus according to claim 16, wherein before determining to create the (n+1)th substream, the first determining unit is further configured to:

Determining that the current number of substreams n in the communication connection is less than a preset maximum number of substreams m, where m is a positive integer.
The device according to claim 16 or 17, wherein the device further comprises:

a second determining unit, configured to determine that there is a substream in the current substream of the communication connection that has a load strength less than the first threshold and has an available transmission window;

a second sending unit, configured to send, on the substream determined by the second determining unit, a second data packet to be sent.
The device according to any one of claims 13 to 18, wherein the device further comprises:

And an updating unit, configured to update a load strength of the (n+1)th substream when the first data packet is transmitted.
The device according to any one of claims 13 to 19, wherein the device further comprises:

a third determining unit, configured to determine, according to a preset second period, whether a substream that needs to be destroyed exists in a current substream of the communication connection;

The destruction unit is configured to destroy the substream that needs to be destroyed when there is a substream that needs to be destroyed.
The device according to claim 20, wherein the third determining unit is specifically configured to:

Determining, according to the second period, the number p of current substreams of the communication connection, where p is a positive integer;

Determining the load strength of each of the p substreams when p is greater than or equal to 2;

The q substreams satisfying the preset condition are determined as substreams to be destroyed, wherein q is an integer smaller than p, and the preset condition includes that the load strength of the substream is less than a preset second threshold.
The device according to claim 20, wherein the third determining unit is specifically configured to:

Determining, according to the second period, the number p of current substreams of the communication connection, where p is a positive integer;

Determining the load strength of each of the p substreams when p is greater than or equal to 2;

A substream having the smallest load intensity among the p substreams is determined as a substream that needs to be destroyed.
The device according to any one of claims 17 to 22, wherein the device further comprises:

a creating unit, configured to create s substreams when the communication connection is established, where s is a positive integer greater than or equal to 1, and s is less than the maximum number of substreams m.
The apparatus according to any one of claims 13 to 23, wherein the load strength is a normalized throughput rate, and the normalized throughput rate is a sub-flow in a unit time, on a unit network interface bandwidth The amount of data transferred.
A network system comprising the apparatus for transmitting data according to any one of claims 13 to 24.