RU2530279C1 - Method for automatic adaptive control of network traffics in software configured networks - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method for automatic adaptive control of network traffics in software configured networks involves variation of network traffic tables of OpenFlow-commutators and OpenFlow-routers, consists in the fact that a network packet is sent to a controller of a software configured network with an additionally activated unit for determination of a network traffic priority, in which a set of quality parameters of network traffic as to ToS bite is determined; in case ToS bite in a network packet is not specified, the least record priority in the network traffic table is assigned to the network packet; if ToS bite in the network packet is specified, then, there determined is priority for network traffic formed with this network packet and al the subsequent network packets that are similar to it on the basis of a method of optimisation as to Priority parameters; the first three bits of ToS bite; Delay, the fourth bit of ToS bite; Carrying Capacity, the fifth bit of ToS bite, and Reliability, the sixth bit of ToS bite; then, in a controller of the software configured network there shaped is OpenFlow-command, by means of which a new record is added to the network traffic table of OpenFlow-commutator or OpenFlow-router.

EFFECT: improving quick action and carrying capacity of OpenFlow-commutators and OpenFlow-routers.

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Description

The invention relates to the field of automation of management of network switches and routers in software-configurable networks, namely, to increase the performance of OpenFlow switches and OpenFlow routers, which constitute the infrastructure of software-configurable networks, based on the dynamic change of priorities of network flows in accordance with changes in network quality parameters traffic specified in network packets.

The rapid growth in the use of automated information systems, distributed computer systems, data centers and network storage systems stimulates the urgent need for reliable, high-performance, well-managed computer networks. Currently, the most actively developing network technology is software-configured networks, in which, unlike traditional computer networks, the decision to change the transmission routes of network packets is made by a dedicated device - the controller of the software-configured network.

To control the transmission of network packets in switches and routers, tables of network flows are used, in which each entry defines a route for a set of similar network packets (network stream) between adjacent network devices. In traditional computer networks, the records that make up the network flow table of each switch and router included in the network are manually set by the system administrator by issuing control commands from the terminal using the FTP, TFTP, SNMP, Telnet, HTTP, HTTPS, SSH control protocols. With the complication of computer network topology, an increase in the number of switches and routers involved, an increase in the number of constantly changing network characteristics that need to be controlled when defining network flow tables, this approach becomes unpromising, since it does not allow dynamic monitoring of constant connections and disconnections of switches and routers, changes in network infrastructure, changes in the volume of data transmitted over the network, increase and decrease in the volume of transmitted data about the data network. For this reason, in software-configured networks, switches and routers are not controlled by a person, but by a controller of a software-configured network, which, according to the OpenFlow protocol, allows you to monitor the state of network nodes and automatically manage them, sending the necessary commands to change the network flow tables to change the route of packets. In software-configured networks, switches and routers controlled by the OpenFlow protocol are called OpenFlow switches and OpenFlow routers.

In OpenFlow switches and OpenFlow routers, the route for a received network packet is determined by comparing the parameters of this network packet with the parameters specified in each record of the network flow table stored on the network device. If a match is found, the network packet is sent along the route specified in the found record. If no record for this packet is found in the network flow table, the packet is sent to the controller for the software-configured network for processing, which generates a new record for this network packet and for all subsequent network packets of the same type, thus adding a new route for this network flow to the network flow table of the corresponding OpenFlow switch and OpenFlow router (US 2011286324, H04L 12/26, publ. 2011-11-24; EP 2408155, H04L 12/56, publ. 2012-01-18).

In existing solutions for managing OpenFlow switches and OpenFlow routers, all entries in the network flow tables are equal, that is, the order of their processing in the table is not specified, which leads to the need to iterate over all entries in the network flow table in search of the desired entry and, accordingly, to temporary delays in the transmission of network packets.

We need a method that allows us to quickly find the desired record that defines the route for newly arriving network packets to the OpenFlow switch and OpenFlow router, and thereby speed up the process of finding the necessary route and, accordingly, increase the performance of the OpenFlow switch and OpenFlow router.

The basis of the invention is the creation of a method for automatically adaptive control of network flows in software-configured networks by implementing dynamic changes to the network flow tables, in which for each record a priority is dynamically calculated based on the quality parameters of network traffic passing through OpenFlow switches and OpenFlow Routers This allows, when determining the route for an incoming network packet, to compare the parameters of this network packet with the parameters specified in each record of the network stream table, in the strict order of decreasing the priority values of the records and thereby reduce the search time for the necessary record in the network stream table and thereby increase the speed processing network packets in OpenFlow switches and OpenFlow routers. The application of this method improves the speed and throughput of OpenFlow switches and OpenFlow routers, improves the reliability of the communication environment, improves the availability of network nodes, reduces administration errors by automating management by dynamically changing the priorities of network flows according to changes in the quality parameters of network traffic.

The solution of the technical problem is provided by the fact that in the method of automatic adaptive control of network flows in software-configurable networks, including the formation of tables of flows of OpenFlow switches and OpenFlow routers, the network packet is sent to the controller of the software-configured network with an additional block for determining the priority of network flow , in which a set of quality parameters of network traffic is determined by ToS byte; if the ToS byte in the network packet is not set, the network packet is assigned the lowest write priority in the network stream table; if the ToS byte in the network packet is specified, then the priority is determined for the network stream generated by this network packet and all subsequent network packets of the same type, based on the multicriteria optimization according to the Priority parameters, the first three bits of the ToS byte; "Delay", the fourth bit of the ToS byte; “Bandwidth”, fifth bit of the ToS byte, and “Reliability”, sixth bit of the ToS byte; then, in the controller of the software-configurable network, an OpenFlow command is formed, with which a new record is added to the network flow table of the OpenFlow switch or OpenFlow router.

The invention is illustrated using figure 1 and figure 2. Figure 1 shows a diagram of adaptive control of network flows in software-configured networks. Figure 2 presents a diagram of adaptive control of network flows in software-configurable networks, correlated with the components of the management of a software-configured network, namely, with an OpenFlow switch (OpenFlow router) and a controller of a software-configured network.

During the operation of a software-configured network, the main task is to set up routing information for organizing and maintaining the transmission of network packets by OpenFlow switches and OpenFlow routers. The solution to this problem is to determine the method of adaptive control of network flows in software-configured networks based on the calculation of priorities of network flows. When a network packet arrives at the input of an OpenFlow switch or OpenFlow router for which there are no corresponding entries in the network flow table, this network device transmits the network packet to the controller of the software-configured network, which receives it, selects the necessary information to create a new entry in the network flow table information is the ToS byte in the network packet. Next, the controller of the software-configured network calculates the priority for the network stream specified by the processed network packet and all subsequent network packets of the same type and creates a new entry in the network stream table of the corresponding network device.

To improve the performance of OpenFlow switches and OpenFlow routers and, accordingly, to ensure the most efficient data transfer, the controller of the software-configured network allocates a byte that is responsible for the transmission quality characteristics of network packets - the ToS byte contained in the network packet. The proposed method for generating network flow tables for a software-configured network is to generate network flow table data based on the priorities of network flows, determined by the contents of the ToS byte of the first network packet of the incoming network stream, for which there is no entry in the network stream table of the corresponding network device.

The controller of the software-configurable network selects the parameters of the packet transmission quality: packet priority; required delay in packet transmission; the required bandwidth when transmitting a packet; and the required reliability when transmitting a packet.

To calculate the priority of the network stream, the priority is calculated using the multicriteria optimization method [Steuer R. Multicriteria optimization: theory, calculations and applications. M .: Radio and communication. 1992].

The essence of the multicriteria optimization method is the simultaneous optimization of two or more conflicting objective functions in a given domain of definition. The problem of multicriteria optimization in the general form is formulated as follows:

$$\underset{}{\underset{\overrightarrow{x}}{\min }\left\{f_{\mathrm{one}}(\overrightarrow{x}),f_2(\overrightarrow{x}),f_3(\overrightarrow{x}),...,f_k(\overrightarrow{x})\right\},\overrightarrow{x}\in S}$$

$$f_i:R^n\to R$$

$$\overrightarrow{x}={(x_{\mathrm{one}},x_2,x_3,...x_n)}^T$$

where f _i - k objective functions, x - solution vectors, S - non-empty domain of definition of functions, k - number of objective functions, R - set of real numbers, n - dimension of the space of the domain of definition of the objective function. The task of multicriteria optimization is to find a vector of target variables that satisfies the constraints and optimizes a vector function whose elements correspond to the objective functions. These functions form a mathematical description of the satisfactory criterion and, as a rule, mutually conflict.

называется оптимальным по Парето, если не существует $${\overrightarrow{x}}_1$$

, такого, что $$f_i(\overrightarrow{x})\le f_i({\overrightarrow{x}}_1)$$

для всех i=1,…, k и $$f_i(\overrightarrow{x})<f_i({\overrightarrow{x}}_1)$$

для хотя бы одного i. Множество оптимальных по Парето решений обозначим как Р(S). Целевой вектор является оптимальным по Парето, если соответствующий ему вектор из области определения также оптимален по Парето. Множество оптимальных по Парето целевых векторов обозначим как P(Z). Множество оптимальных по Парето векторов является подмножеством оптимальных по Парето в слабом смысле векторов. Вектор $${\overrightarrow{x}}_1\in S$$

является слабым оптимумом по Парето тогда, когда не существует вектора $${\overrightarrow{x}}_1\in S$$

такого, что $$f_i(\overrightarrow{x})<f_i({\overrightarrow{x}}_1)$$

для всех i=1,…,k.As a performance criterion, the Pareto criterion is used. Solution Vector $$\overrightarrow{x}$$

called Pareto optimal if not exist $${\overrightarrow{x}}_{\mathrm{one}}$$

such that $$f_i(\overrightarrow{x})\le f_i({\overrightarrow{x}}_{\mathrm{one}})$$

for all i = 1, ..., k and $$f_i(\overrightarrow{x})<f_i({\overrightarrow{x}}_{\mathrm{one}})$$

for at least one i. The set of Pareto optimal solutions is denoted by P (S). The target vector is Pareto optimal if the corresponding vector from the domain is also Pareto optimal. The set of Pareto optimal target vectors is denoted by P (Z). The set of Pareto optimal vectors is a subset of the Pareto optimal in the weak sense of the vectors. Vector $${\overrightarrow{x}}_{\mathrm{one}}\in S$$

is a weak Pareto optimum when there is no vector $${\overrightarrow{x}}_{\mathrm{one}}\in S$$

such that $$f_i(\overrightarrow{x})<f_i({\overrightarrow{x}}_{\mathrm{one}})$$

for all i = 1, ..., k.

. Его компоненты z_i получены путем минимализации каждой целевой функции в пределах области определения.The range of values of Pareto optimal solutions in the range of admissible values gives useful information about the problem under study if the objective functions are limited by the domain of definition. The lower bounds of the Pareto optimal set are represented in the “ideal target vector” $$\overrightarrow{z}\in R^k$$

. Its components z _{i are} obtained by minimizing each objective function within the domain of definition.

To obtain Pareto optimal solutions, the scalarization method is used by weighted summation in accordance with the formula

. $$F_{\mathrm{one}}\left(\overrightarrow{f}(\overrightarrow{x})\right)=w_{\mathrm{one}}{f}_{\mathrm{one}}(\overrightarrow{x})+...+w_r{f}_r(\overrightarrow{x})$$

.

Significant ToS bits are used as components of the vector x: X ₁ - priority value (3 ToS bits), X ₂ - delay requirements, X ₃ - bandwidth requirements, X ₄ - reliability requirements. The following functions are defined as objective functions:

$$f_{\mathrm{one}}(\overrightarrow{x})=\{\begin{array}{l}{X}_{\mathrm{one}}0\le X_{\mathrm{one}}\le 2\\ 2X_{\mathrm{one}}\mathrm{,\; 3}\le X_{\mathrm{one}}\le 5\\ 3X_{\mathrm{one}}\mathrm{,\; 6}\le X_{\mathrm{one}}\le 7\end{array}$$

$$f_2(\overrightarrow{x})=X_{\mathrm{one}}{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="00000023.png"\; state="\{\{state\}\}">X</figure-callout>}}_2$$

$$f_3(\overrightarrow{x})=X_{\mathrm{one}}{X}_3$$

$$f_{\mathrm{four}}(\overrightarrow{x})=X_{\mathrm{one}}{X}_{\mathrm{four}}$$

Scalarization using a weighted sum when generating network flow tables includes four components.

$$F_{\mathrm{one}}\left(\overrightarrow{f}(\overrightarrow{x})\right)=w_{\mathrm{one}}{f}_{\mathrm{one}}(\overrightarrow{x})+w_2{f}_2(\overrightarrow{x})+w_3{f}_3(\overrightarrow{x})+w_{\mathrm{four}}{f}_{\mathrm{four}}(\overrightarrow{x})$$

This method is universal due to the fact that for each network interaction system, its own values of the weight coefficients w _i can be determined.

.Thus, to set the recording priority in the flow table of the OpenFlow switch or OpenFlow router, the value of the function is used $$F_{\mathrm{one}}\left(\overrightarrow{f}(\overrightarrow{x})\right)$$

.

Consider the example of determining the priority for a network packet whose TOS byte has a binary value of 10110100. According to the ToS byte format, this means that the priority value is 101, the delay requirement is high, and the reliability of packet transmission is high.

$$\begin{array}{l}T\mathrm{about}gd\mathrm{but}{f}_{\mathrm{one}}=2*5=\mathrm{10,}{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="00000023.png"\; state="\{\{state\}\}">f</figure-callout>}}_2=10*\mathrm{one}=\mathrm{10,}{f}_3=10*0=0\\ f_{\mathrm{four}}=10*\mathrm{one}=\mathrm{10,}{F}_{\mathrm{one}}\left(\overrightarrow{f}(\overrightarrow{x})\right)=w_{\mathrm{one}}\times f_{\mathrm{one}}(\overrightarrow{x})+{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="00000023.png"\; state="\{\{state\}\}">w</figure-callout>}}_2\times f_2(\overrightarrow{x})+\\ w_3\times f_3(\overrightarrow{x})+w_{\mathrm{four}}\times f_{\mathrm{four}}(\overrightarrow{x})=w_{\mathrm{one}}\times 10+{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="00000023.png"\; state="\{\{state\}\}">w</figure-callout>}}_2\times 10+w_3\times 0+w_{\mathrm{four}}\times 10\end{array}$$

. Таким образом, значение приоритета записи для соответствующего сетевого потока, создаваемой в таблице сетевых потоков, составляет $$F_1\left(\overrightarrow{f}(\overrightarrow{x})\right)=35$$

. Все сетевые потоки, у которых в записи в таблице сетевых потоков установлен более высокий приоритет, будут обработаны раньше, более низкий - позже. Приоритезация записей и, соответственно, сетевых потоков, позволяет сократить время обнаружения записи в таблице сетевых потоков за счет создания очередности записей по приоритетам.Let this segment of the software-configured network should provide the fastest data transfer, but at the same time take into account the priority of this traffic. Then we set the weight coefficients w ₁ = 1, w ₂ = 2, w ₃ = 0.5, w ₄ = 0.5. Then $$F_{\mathrm{one}}\left(\overrightarrow{f}(\overrightarrow{x})\right)=w_{\mathrm{one}}\times f_{\mathrm{one}}(\overrightarrow{x})+{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="00000023.png"\; state="\{\{state\}\}">w</figure-callout>}}_2\times f_2(\overrightarrow{x})+w_3\times f_3(\overrightarrow{x})+w_{\mathrm{four}}\times f_{\mathrm{four}}(\overrightarrow{x})=\mathrm{one}\times 10+2\times 10+0.5\times 10=35$$

. Thus, the write priority value for the corresponding network stream created in the network stream table is $$F_{\mathrm{one}}\left(\overrightarrow{f}(\overrightarrow{x})\right)=35$$

. All network streams that have a higher priority in the entries in the network stream table will be processed earlier, lower - later. Prioritization of records and, accordingly, network streams allows reducing the time of record detection in the table of network streams by creating a sequence of records by priority.

The described method provides an increase in the speed and throughput of OpenFlow switches and OpenFlow routers, an increase in the reliability of the data exchange medium, an increase in the availability of network nodes, and reduction of administration errors due to automation of control by dynamically changing the priorities of network flows according to changes in the quality parameters of network traffic.

Claims (1)

 A method for automatically adaptive control of network flows in software-configurable networks, including changing the network flow tables of OpenFlow switches and OpenFlow routers, characterized in that the network packet is sent to the controller of the software-configured network with an additional network flow priority determining unit, in which it is determined set of network traffic quality parameters by ToS byte; if the ToS byte in the network packet is not set, the network packet is assigned the lowest write priority in the network stream table; if the ToS byte in the network packet is specified, then the priority is determined for the network stream generated by this network packet and all subsequent network packets of the same type, based on the multicriteria optimization according to the Priority parameters, the first three bits of the ToS byte; "Delay", the fourth bit of the ToS byte; “Bandwidth”, fifth bit of the ToS byte, and “Reliability”, sixth bit of the ToS byte; then, in the controller of the software-configurable network, an OpenFlow command is formed, with which a new record is added to the network flow table of the OpenFlow switch or OpenFlow router.

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