KR101524472B1 - Method and Device for Routing Multipath of Network - Google Patents

Abstract

Disclosed are a method and a device for setting multi-paths which minimize a transmission delay in network. The disclosed method for setting multi-paths comprises the steps of: generating self-similarity information of the network and transmission capacity information of the network link; determining the number of data transmission paths to a destination node which minimizes the transmission delay by using the self-similarity information and the transmission capacity information; and setting the transmission paths in less than the number above and allocating a traffic to the transmission path, by using the self-similarity information and the transmission capacity information.

Description

[0001] The present invention relates to a method and an apparatus for setting a multi-path in a network,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for multipath establishment in a network, and more particularly, to a multipath establishment method and apparatus capable of minimizing transmission delay in a network.

When data is transmitted in the network, multipath routing is used. Multipath routing is a method in which a plurality of paths are set up for data transmission between two terminals and a necessary path is used for data transmission. When a part of the paths is lost or an error occurs, data transmission is performed in another path. There is an advantage to be maintained. Multipath routing is a technology that requires optimization of various technologies such as transmission path management, transmission scheduling, and congestion control technology by using two or more paths.

Multipath routing protocols include Stream Control Transmission Protocol (SCTP), Multipath Transmission Control Protocol (MPTCP), and Ad hoc On-Demand Distance Vector (AODV), which are enacted in RFC 2960 in October 2000 by the IETF. And the AOMDV (Ad hoc On-Demand Multipath Distance Vector) protocol, which is extended for multipathing.

There are ADM (Average Delay Minimization) algorithm and MDM (Maximum Delay Minimization) algorithms for distributing traffic to multiple paths after multipath is established according to multipath routing protocol. The AMD algorithm and the MDM algorithm assume that the network traffic follows the Poisson distribution, the ADM algorithm minimizes the average time delay of the multipath, and the MDM can minimize the maximum time delay of the multipath.

However, since the traffic of the actual network has a self-similar characteristic, when traffic distribution is performed according to the ADM and MDM algorithms, there is a disadvantage in that optimization is not performed due to erroneous traffic modeling.
As a prior art related thereto, there is Korean Patent Publication No. 2003-0033711 (published on 2003.05.01).

The present invention provides a multi-path establishment method and apparatus capable of minimizing transmission delay in a network.

According to an embodiment of the present invention, there is provided a method for providing a service providing method, the method comprising: generating self similarity information and transmission capacity information of a network link of the network; Determining a number of data transmission paths to a destination node that minimizes transmission delay using the self similarity information and transmission capacity information; And establishing a transmission path using the self similarity information and the transmission capacity information, the transmission path being less than or equal to the number, and allocating traffic to the transmission path.

According to another aspect of the present invention, there is provided a method for controlling a network link, the method comprising: determining a number of data transmission paths to a destination node that minimizes a transmission delay according to a queue length of the network link; Setting a transmission path below the number using the transmission capacity information of the network link; And allocating traffic to the transmission path using the self similarity information and the transmission capacity information of the network

According to another aspect of the present invention, there is provided a method of transmitting data, comprising: receiving data; Using the data to generate self similarity information of the node; Generating a message including the self similarity information and the transmission capacity information of the node; And transmitting the message to a predetermined node.

According to another embodiment of the present invention, there is provided an information generating apparatus for generating self similarity information and transmission capacity information of a network link, A determination unit for determining the number of data transmission paths to a destination node that minimizes a transmission delay using the self similarity information and transmission capacity information; And a path setting unit for setting a transmission path below the number using the self similarity information and transmission capacity information, and allocating traffic to the transmission path.

According to the present invention, it is possible to set a multipath that can minimize the transmission delay from the network to the destination node.

According to the present invention, the number of data transmission paths for minimizing the transmission delay is calculated first, the transmission path is selected below the calculated number, and the traffic is allocated, so that the calculation amount and time required for setting the optimum multiple transmission path .

1 is a diagram for explaining a concept of a multipath setting method according to the present invention.
2 is a diagram for explaining a multipath setting method according to an embodiment of the present invention.
3 is a diagram for explaining a message exchanged between nodes according to an embodiment of the present invention.
FIGS. 4 and 5 are diagrams for comparing the performance of the multi-path establishment method (SDM), the ADM and the MDM algorithm according to an embodiment of the present invention.
6 is a diagram for explaining a multipath setting apparatus according to an embodiment of the present invention.
7 is a diagram for explaining a multipath setting apparatus according to a specific embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

1 is a diagram for explaining a concept of a multipath setting method according to the present invention. In Fig. 1, a network composed of 17 routers is described as an embodiment.

As shown in Fig. 1, there may be a plurality of data transmission paths between each node (router or user terminal). For example, when data is transmitted from the first node to the eighth node, data is not transmitted only through one path, but one or more paths among a plurality of data transmission paths are selected, traffic is allocated, Is transmitted.

The present invention provides a multipath setting method capable of minimizing a transmission delay time among a plurality of data transmission paths existing in a network. As shown in Fig. 1, since there are many transmission paths between nodes, considerable computation and time are required to set an optimum transmission path. The present invention can reduce the computation time required for setting an optimal path . To this end, the present invention first calculates the number of data transmission paths that minimize the transmission delay, selects transmission paths below the calculated number, and allocates traffic.

The multipath setting method according to the present invention can be performed in a node of a network and can be performed in both a source node and a destination node. A node in the network may also be a user terminal connected to a router or router.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram for explaining a multipath setting method according to an embodiment of the present invention.

The router according to the present invention generates self-similarity information of the network and transmission capacity information of the network link (S201). The router may receive traffic information and network information from other nodes in the network, and may generate self similarity information and transmission capacity information of the network link. Traffic information and network information can be transmitted and received in the form of a message.

The self similarity information is traffic related information and may include a standard deviation of traffic, an average transmission rate of traffic, an overflow probability, and a Hurst parameter. The Hurst parameter is a parameter indicating the degree of self-similarity. The transmission capacity information may be information on the average transmission capacity of the link.

The router determines the number of data transmission paths from the self similarity information and the transmission capacity information to the destination node that minimizes the transmission delay (S203). The router can calculate the queue length of each link by using the self similarity information and the transmission capacity information, and determines that the link having the smallest remaining queue length, that is, a small load, is a data transmission path that minimizes the transmission delay. For example, if the number of data transmission paths is determined to be five, the router can select five or less transmission paths and allocate traffic in step S205 described later.

, 트래픽 표준 편차를

, 트래픽 분배율을

, Hurst parameter를

, 오버플로우 확률을

, 각 링크(u,v)의 전송 용량(캐패시티)를

라 할 때, 각 링크의 큐 길이

는 [수학식 1]과 같이 구할 수 있다. 여기서, 트래픽 분배율은 기 설정된 값으로 할당될 수 있으며, 예를 들어 균등하게 분포되는 값으로 설정될 수 있다.As one embodiment, the router may determine the number of data transmission paths according to the convex optimization algorithm. The average traffic transfer rate of the i th transmission path

, The traffic standard deviation

, The traffic distribution rate

, Hurst parameter

, The overflow probability

, The transmission capacity (capacity) of each link (u, v)

, The queue length of each link

Can be obtained as shown in Equation (1). Here, the traffic distribution rate may be assigned to a predetermined value, and may be set to, for example, an evenly distributed value.

를 정의하면, n개의 전송 경로를 구성하는 링크의 큐 길이를 합산한 값과 대응되는, 전송 지연 시간 d(n)은 [수학식 2]와 같이 얻을 수 있다. 즉, d(1)은 제1경로를 구성하는 링크의 큐 길이를 합산한 값이 되며, d(2)는 제2경로를 구성하는 링크의 큐 길이를 합산한 값이 된다.To simplify the expression

, The transmission delay time d (n) corresponding to the sum of the queue lengths of the links constituting the n transmission paths can be obtained as shown in Equation (2). That is, d (1) is a value obtained by summing the queue lengths of the links constituting the first path, and d (2) is a value obtained by summing the queue lengths of the links constituting the second path.

)는 평균 캐패시티(

) 및 종단간 평균 홉 수(l)로 추정될 수 있으며, 이에 따라 [수학식 2]는 아래 [수학식 3]과 같이 표현될 수 있다.The capacity of all links (u, v)

) Is the average capacity (

) And the end-to-end average number of hops (1), and thus, Equation (2) can be expressed as Equation (3) below.

은 평균 캐패시티 값을 이용한 d(n)의 추정치로 그 값의 차이가 있으나, 그 차이

값은 고정 값으로 수렴한다. 즉, 링크 캐패시티의 최소값을

이라할 때

가 성립하며, 링크 캐패시티의 최대값을

라 할 때

가 성립하므로

는

보다 작은 값을 가진다.

Is the estimated value of d (n) using the average capacity value,

The value converges to a fixed value. That is, the minimum value of the link capacity

When you say

And the maximum value of the link capacity is

When

So that

The

Lt; / RTI >

는 컨벡스 함수이므로 전송 경로의 수 n에 대해 다음과 같이 컨벡스 최적화를 수행할 수 있다.

을 n에 대해 미분한 함수

는

일 때 그 값이 0이 되며, 미분값

이 성립하는 n은 전송 경로의 전송 지연 시간(

)을 최소화 하는 경로의 개수가 된다. 이로부터, 전송 경로의 전송 지연 시간 추정값(

)을 최소화하는 데이터 전송 경로의 개수(

)를 [수학식 4]와 같이 구할 수 있다. At this time,

Is a convex function, convex optimization can be performed on the number n of transmission paths as follows.

The derivative function for n

The

The value becomes 0, and the derivative value

N is the transmission delay time of the transmission path (

) Is minimized. From this, the transmission delay time estimation value (

The number of data transmission paths (

) Can be obtained as shown in Equation (4).

는 천장 함수(ceiling function)로

와 같이 정의되며, Z는 정수의 집합이다.
here,

Is a ceiling function.

And Z is a set of integers.

The router sets the transmission path to a number equal to or less than the number of data transmission paths determined in step S203 using the self similarity information and the transmission capacity information of the network link, and allocates the traffic to the set transmission path (S205). More specifically, the router sets the transmission path, which is the minimum cost path, using the transmission capacity information, and allocates the traffic to the transmission path using the self similarity information and the transmission capacity information.

In one embodiment, the router can determine the minimum cost path by calculating the reciprocal of the link's transmission capacity as the routing cost, according to the Suurballe algorithm. In other words, the transmission capacity and the routing cost are inversely related. For example, if the network has a total transmission path of 100 and the number of transmission paths that minimizes the transmission delay is 5, then the router may transmit a set of five or less transmission paths that can minimize the routing cost to the transmission path And the thus set transmission path becomes the minimum cost path.

Then, the router allocates the traffic to the transmission path using the self similarity information and the transmission capacity information. More specifically, the router calculates the traffic distribution ratio that minimizes the transmission delay using the self similarity information and the transmission capacity information, and allocates the traffic to the set transmission path according to the traffic distribution ratio. As one embodiment, the router can allocate traffic by calculating a traffic distribution rate according to game theory.

)은 [수학식 5]와 같이 정의될 수 있다. 전송 경로의 협력 함수

를 위해 i번째 전송 경로에 대한 트래픽 분배

의 초기값은 균등 배분 1/n이며, 트래픽의 표준편차

는

라 가정한다. 즉, 트래픽은 균등분포(Uniform Distribution)를 따른다.The gain for the transmission time delay when n transmission paths included in the least cost path set cooperate to transmit data

) Can be defined as [Equation 5]. Cooperative function of transmission path

Lt; RTI ID = 0.0 > i < / RTI >

Is equal to 1 / n, and the standard deviation of traffic

The

. That is, the traffic follows a uniform distribution.

,{1},{2},{3},{1,2},{1,3},{2,3},{1,2,3}이며, A는 {

,{1},{2},{3},{1,2},{1,3},{2,3},{1,2,3}}일 수 있다.
Here, S represents a coalition set between transmission paths, and A represents a grand coalition set. For example, when there are three transmission paths (n), S

, {2}, {3}, {1,2}, {1,3}, {2,3}, {1,2,3}

, {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, {1,2,3}}.

는 Shapley value로 설정된다.From Equation (5), the Shapley value can be obtained as shown in Equation (6). The Shapley value represents the year in which the utility for the transmission path cooperation becomes the maximum, that is, the minimum transmission time delay. Percentage of traffic distributed across each transmission path

Is set to the Shapley value.

는

번째 경로에 대한 Shapley value를 의미한다.
here,

The

The second path is the Shapley value for the second path.

As described above, according to the present invention, it is possible to set up a multiplex transmission path capable of minimizing a transmission delay, to first calculate the number of data transmission paths that minimize the transmission delay, to select a transmission path below the calculated number, It is possible to reduce the amount of computation and the time required for setting the optimum multiple transmission path.

Also, according to the present invention, since a packet is transmitted by selecting a path having a small queue length and a small transmission delay, the average queue length of the router is reduced, so that a packet drop due to RED (Random Early Detection) The transmission reliability can be guaranteed.

On the other hand, when the data transmission path is recalculated in response to a small change in the communication environment, frequent transmission path re-establishment may cause network instability. On the other hand, if the response to the change in the communication environment is insensitive, the end-to-end time delay experienced by the network and the terminal may be significantly different from the optimal solution.

The multi-path setting method according to an exemplary embodiment of the present invention may further include determining whether a rate of change of the transmission delay time exceeds a predetermined threshold range in order to more efficiently set a multi-path. The router can update the number of data transmission paths according to whether the threshold range is exceeded or not.

That is, according to the present invention, when the transmission time delay increases or decreases in the transmission path set by the change of the network environment, the number of data transmission paths is determined again according to whether the rate of change of the transmission delay time exceeds a preset threshold range Reset the transmission path and allocate traffic.

The rate of change of the transmission delay time can be expressed as in Equation (7), and can be derived from Equation (3).

과

는 각각 임계 범위의 하한(lower bound) 및 상한(upper bound)를 의미하며,

은 변화한 트래픽의 평균 전달 속도를 의미한다.
here,

and

Respectively denote a lower bound and an upper bound of the critical range,

Means the average transmission speed of the changed traffic.

3 is a diagram for explaining a message exchanged between nodes according to an embodiment of the present invention.

), 트래픽 표준 편차(

), 허스트 파라미터(

), 오버플로우 확률(

)를 포함한다. 오버플로우 확률이란 노드로 입력되는 트래픽에 의한 데이터가 해당 노드의 큐 길이보다 길 확률을 나타낸다.In the message shown in FIG. 3, a Hop Count, a Prefix Size, a Destination IP Address, a Destination Sequence Number, an Originator IP Address, and an Originator Sequence Number field are fields included in a message used in conventional routing. The message field according to the present invention includes self similarity information of the node and transmission capacity information of the node. The self-similarity information includes the traffic average transfer rate (

), Traffic standard deviation (

), Hurst parameter (

), An overflow probability (

). The overflow probability indicates the probability that data due to traffic input to the node is longer than the queue length of the corresponding node.

According to an embodiment of the present invention, a node of the network generates data of self similarity of the node using data received according to the traffic occurrence. Then, a message including the self similarity information of the node and the transmission capacity information of the node is generated and transmitted to the predetermined node.

The node receiving the message according to the present invention can generate the self similarity information and the transmission capacity information of the network by using the traffic information and the network information of the node constituting the network and set the multipath according to the present invention.

FIG. 4 and FIG. 5 are diagrams for comparing the performance of the ADM and MDM algorithms with the Multipath Establishment Method (SDM) according to an embodiment of the present invention, and show simulated results on the network shown in FIG.

More specifically, the network of FIG. 1 is an optical network, which includes 17 routers and is connected to a backbone network and a uniform random distribution that supports a transmission rate of 155.52 Mbps with Carrier 3 (OC-3) It consists of a random network consisting of 40 nodes.

)를 1 Gbps에서 4 Gbps까지 변화시키며 속도 변화에 따른 종단간 시간 지연 결과를 분석한 시뮬레이션 결과이다. 백본 네트워크에서 트래픽 평균 전달 속도(

)가 4 Gbps일 때 SDM은 4.76 초의 전송 시간 지연을 보이며, MDM은 12.39 초, ADM은 9.97초의 전송 시간 지연 성능을 보인다. 랜덤 네트워크에서 트래픽 평균 전달 속도(

)가 4 Gbps일 때 SDM은 2.63 초, MDM은 5.85 초, ADM은 4.27 초의 시간 지연을 보인다. 1~4 Gbps에서의 시간 지연 성능 평균을 비교할 때, 백본 네트워크에서 SDM의 전송 지연 시간은 MDM과 ADM에 비해 각각 51.40%, 66.06% 단축되며, 랜덤 네트워크에서 SDM의 전송 지연 시간은 MDM과 ADM에 비해 각각 32.47%, 45.80% 단축된다.4 is a graph illustrating the average traffic delivery rate

) Is changed from 1 Gbps to 4 Gbps and the end-to-end time delay results according to the speed change are analyzed. Average traffic throughput on the backbone network (

) Is 4 Gbps, the SDM shows a transmission time delay of 4.76 seconds, the MDM is 12.39 seconds, and the ADM is 9.97 seconds. Average traffic throughput in random networks (

) Is 4 Gbps, SDM has 2.63 seconds, MDM has 5.85 seconds and ADM has 4.27 seconds. The transmission delay time of the SDM in the backbone network is reduced by 51.40% and 66.06%, respectively, compared with that of the MDM and the ADM, and the transmission delay time of the SDM in the random network is compared with the MDM and ADM Compared with 32.47% and 45.80%, respectively.

)를 1 Gbps에서 4 Gbps까지 변화해갈 때, 백본 네트워크와 랜덤 네트워크에서 RED에 의한 패킷 손실을 0 초에서 10,000 초까지 관찰한 시뮬레이션 결과이다. 백본 네트워크에서 SDM의 패킷 손실율은 MDM, ADM의 패킷 손실율의 74.44%, 67.78%에 해당하며, 랜덤 네트워크에서 SDM의 패킷 손실율은 MDM, ADM의 패킷 손실율의 77.08%, 68.21%에 해당한다.
5 is a graph illustrating the average traffic delivery rate

) Is changed from 1 Gbps to 4 Gbps, and the packet loss due to RED is observed from 0 to 10,000 seconds in the backbone network and the random network. In the backbone network, the packet loss rate of SDM corresponds to 74.44% and 67.78% of the packet loss rate of MDM and ADM, and the packet loss rate of SDM in the random network corresponds to 77.08% and 68.21% of the packet loss rate of MDM and ADM.

6 is a diagram for explaining a multipath setting apparatus according to an embodiment of the present invention.

6, the multipath routing apparatus according to the present invention includes an information generation unit 601, a determination unit 603, and a path setting unit 605.

The information generation unit 601 generates self similarity information of the network and transmission capacity information of the network link. The information generation unit 601 may receive the traffic related information and the transmission capacity information from another node and generate the self similarity information and the transmission capacity information of the network link.

The determination unit 603 uses the self similarity information and the transmission capacity information to determine the number of data transmission paths to the destination node that minimizes the transmission delay. The path setting unit 605 sets the multiplex transmission path to a number less than the determined number and allocates the traffic to the multiplex transmission path using the self similarity information and the transmission capacity information.

Meanwhile, the determination unit 603 of the multipath routing apparatus according to the present invention can determine whether the rate of change of the transmission delay time exceeds a predetermined threshold range, and updates the number of data transmission paths according to whether the threshold value range is exceeded or not can do.

7 is a diagram for explaining a multipath setting apparatus according to a specific embodiment of the present invention.

7, the multipath routing apparatus according to the present invention includes a communication unit 710, a processor unit 720, and a power supply unit 730.

The communication unit 710 may include an input / output interface for transmitting / receiving data to / from a peripheral node. The communication unit 710 transmits data according to the control of the processor unit 720 and transfers the received data to the processor unit 720.

The processor unit 720 includes a controller 721 and a storage unit 729. The controller 721 performs the convex optimization using the information generation unit 723 that scans the network status and traffic parameters and generates the self similarity information and the transmission capacity information of the network link, the self similarity information and the transmission capacity information, A determination unit 725 that determines the number of data transmission paths that minimize a transmission delay time to a node, a minimum cost path set as a transmission path using self similarity information and transmission capacity information, And a transmission path setting unit 727 for allocating traffic according to the theory. The storage unit 729 stores the data processed by the controller 721 and the data received through the communication unit 710.

The power supply unit 730 supplies power to the communication unit 710 and the processor unit 720.

The above-described technical features may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (13)

In a multipath setting method in a network,
Generating self similarity information of the network and transmission capacity information of the network link;
Determining a number of data transmission paths to a destination node that minimizes transmission delay using the self similarity information and transmission capacity information; And
Setting a transmission path below the number using the self similarity information and transmission capacity information, and allocating traffic to the transmission path;
The step of assigning traffic to the transmission path
Setting a minimum cost path set as the transmission path using the transmission capacity information; And
Allocating traffic to the transmission path using the self similarity information and transmission capacity information
/ RTI >
delete The method according to claim 1,
The step of assigning traffic to the transmission path
Calculating a traffic share ratio that minimizes the transmission delay using the self similarity information and the transmission capacity information; And
Allocating the traffic according to the traffic distribution rate
/ RTI >
The method according to claim 1,
The step of assigning traffic to the transmission path
According to game theory,
How to set up multipath.
The method according to claim 1,
The self similarity information
Standard deviation of traffic, average transmission rate of traffic, overflow probability and Hurst parameter
/ RTI >
The method according to claim 1,
Further comprising the step of determining whether the rate of change of the transmission delay time exceeds a predetermined threshold range,
The step of determining the number of data transmission paths
And updates the number of the data transmission paths according to whether the threshold range is exceeded or not
How to set up multipath.
The method according to claim 1,
The data transmission path to the destination node that minimizes the transmission delay is
Is determined according to the queue length of the network link
How to set up multipath.
The method according to claim 1,
The step of determining the number of data transmission paths
According to the convex optimization algorithm, the number of the data transmission paths is determined
How to set up multipath.
In a multipath setting method in a network,
Determining a number of data transmission paths to a destination node that minimizes a transmission delay according to a queue length of the network link; And
Setting a transmission path below the number using the transmission capacity information of the network link; And
Allocating traffic to the transmission path using the self similarity information and the transmission capacity information of the network
/ RTI >
delete delete 1. A multipath setting apparatus for a network,
An information generating unit for generating self similarity information of the network and transmission capacity information of the network link;
A determination unit for determining the number of data transmission paths to a destination node that minimizes a transmission delay using the self similarity information and transmission capacity information; And
And a path setting unit that sets a transmission path below the number using the self similarity information and transmission capacity information and allocates traffic to the transmission path,
The determination unit
Determines whether the rate of change of the transmission delay time exceeds a predetermined threshold range, and updates the number of the data transmission paths according to whether the rate exceeds the threshold range
Multipathing device.
13. The method of claim 12,
The multipath setting device
A router or a user terminal connected to the router
Multipathing device.

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