Українська   Русский
DonNTU   Masters' portal

Abstract

Maintenance

Introduction

Modern rates of development of multimedia services, systems of automation of business processes and growth of the amount of information resources impose more severe demands on telecommunication systems. First of all, the convergence of services in the networks of the new generation requires from the communication channels high quality indicators: lower delays and its variations, guaranteed throughput, etc. In turn, most business processes of a modern enterprise require timely provision of reliable information, for this telecommunications network should have a sufficient level of reliability. On the other hand, improving the characteristics of the network requires additional costs to use more, more quality channels of communication, the installation of additional equipment. Thus, there is a problem of efficient use of economical and technical resources of the enterprise.

The solution to the problem lies in the development of effective methods for optimizing the distribution of data flows and designing telecommunications networks, taking into account effective allocation.

1. Relevance of the topic

Telecommunication networks are developing incredibly fast. Every year, the requirements for quality are growing, as are the needs of subscribers to the network. The issue of optimizing the distribution of data flows in telecommunication networks is considered by scientists and specialists of different countries. Providing services with guaranteed parameters are considered in academia. Considerable attention is paid to the company-developers of network equipment CISCO Systems, Juniper Networks, Huawei Technologies, etc.

2. Goal and tasks of the research

The goal of the work is to minimize the cost of operating the transport segment of the corporate network while preserving the quality of service by developing an algorithm for distributing data flows depending on traffic parameters and characteristics of communication channels.

The main objectives of the research:

  1. To analyze the traffic that is transmitted in the corporate network
  2. Develop criteria for assessing the performance of the transport segment of the corporate network
  3. Consider the option of building a corporate network using the proposed special router
  4. Develop a mathematical and software model for the operation of a special router
  5. Conduct an experimental research of the router, using the data of the considered version of the corporate network
  6. To analyze the simulation results
  7. To analyze the indicators of the economical efficiency of the proposed solution
  8. Provide recommendations of the use of the developed technique of the construction of the enterprise network using a special router and its models

3. General questions of building multiservice networks of corporate networks

3.1 Trends in the development of corporate networks

There are three factors that determine the development of telecommunications networks: traffic growth, the need of society for new services and the latest advances in technology. All these factors are inextricably interrelated, but each of them influences the ideology of the development of telecommunications.

The need for new services, traffic growth lead to a change in the principles of building networks. In the 1980s, optical technologies, analog wireless networks were innovative, and networks based on the X.25 standard were widely used. In the 1990s, mobile networks of the second generation were actively developed and introduced;[1] optical technologies were developed based on multiplexing with separation and multiplexing along the wavelength, the global Internet network was rapidly developing.[2]

To date, the vector of development of telecommunications networks is aimed at the concept of convergent networks of a new generation (Next Generation Networks – NGN). [3] NGN is the concept of building communication networks that provide an unlimited range of services with flexible capabilities to manage, personalize and create new services by unifying network solutions, providing for the implementation of a universal transport network with distributed switching, rendering the functions of providing services to finite network nodes and integrating with traditional communication networks.

Directions of modern developments associated with the creation of integrated solutions that allow the development of next-generation networks to maintain existing connections and ensure continuous operation in any network, and where to obtain the full range of services. Similarly, corporate multiservice networks are being built. By definition, corporate networks are enterprise-wide networks. Such networks unite a large number of nodes in all the territories of a single enterprise.[4] They can be difficult to connect and cover the city, region or even the continent. The number of users and computers can vary depending on the nature of the enterprise, the purpose of the branch, on the size of the company. Branches of one company can be located within the same city, country, as well as located on different continents. To connect remote local networks and individual computers in a corporate network, separate wired and wireless communication channels are used, logical channels are organized both on public networks (the Internet) and on closed networks of telecom operators.

3.2 Architecture of corporate networks

In general, each corporate network by analogy of the OSI model can be represented in the form of several interacting layers.

The lower level is the subscriber terminals (computers, IP telephones, servers). Subscriber terminals are connected by a different level – the transport system. The main purpose of the first two levels is to ensure the accumulation, processing and reliable transmission of data.

The next level is network operating systems. At this level, the work of additions of different terminals is organized, which interact with each other through the transport system.

Separate level of service systems. System services include a database management system, web servers, mail servers, as well as server additions to the enterprise resource planning system. Databases provide the ability to maintain the basic corporate information in an orderly manner and implement basic

Search for it and ensure the operation of the ERP-system. Web, mail servers, instant messaging servers and others provide the work of information exchange services in the enterprise, processing of user data.

At the next level, there are applications that represent an interface for accessing databases, system services, and give users all the information in a form that is convenient for decision making.

The levels considered are typical for any enterprise. More specific tools are highlighted at the next level. Special software systems that perform tasks specific to a given enterprise or enterprise of this type. Examples of such systems can serve ERP-systems, which form a standardized unified information space of the enterprise. For example, the bank's automation systems, accounting organizations, design automation, process management, etc.

The main purpose of the corporate network is to ensure the operation of the upper two levels of a single hierarchy. Strategic decisions about the organization of these levels, as a rule, affect several parts of this hierarchy at the same time, although at first only one specific level or even a separate subsystem of this level is concerned. Such mutual influence of products and solutions must be taken into account when planning the technical policy of network development, otherwise you may face the need for urgent and unforeseen replacement, for example, network technology, because this new application is more demanding for the bandwidth of communication channels or data transfer delays.

3.3 Features of providing services in corporate networks

Recently, the actual development of telecommunication networks of the enterprise is the convergence of telecommunication services. At the same time, each service presents its own requirements to communication channels, and also the question of quality of service (Qos) in these networks appears. Qos is the ability of the communication system to provide a certain level of quality of services depending on the type of data that is transmitted under the existing technological limitations of the network.

Quality parameters include the following parameters:

All values of service quality indicators are normalized in accordance with the recommendation of the International Telecommunication Union Y.1541 (13).

At the moment the most used services are:

  1. Data transmission service. For example, text messages, e-mail, documents, service information, etc. Refers to the 4th class.
  2. Database management service. It is designed for centralized management and organization of access to user information in the enterprise. Refers to the 3rd class.
  3. Voice communication service. Refers to 0 or 1 class.
  4. Video conferencing service. Similarly, voice communication refers to 0 or 1 class.

3.4 Principle of organization of telecommunication infrastructure of corporate networks

A corporate network consists of different subsystems, which can be a local network.[5] The network of subsystems is integrated into a single corporate network using global communication channels – a transport network. There are several options for the organization:

- use of dedicated communication channelsuse of dedicated communication channels

- use of virtual communication channels within the network of the operator of communication

- the use of virtual channels on a public network

[6]For the organization of virtual networks, different technologies can be used. For example:

3.5 Service quality assurance mechanisms in multiservice networks

The most important task in building a network is to provide the necessary level of service (QoS) created by the network. Quality of service means that the network will transmit a certain data stream between the two nodes, respectively, to the requirements of the programs or the user. The network must guarantee the specific quality of service parameters formulated for each individual add-on.

When providing quality of service, the following network indicators are analyzed:

Quality of service is guaranteed for some data flow. Threads such as aggregation and differentiation are applied to flows. So the data stream from one computer can be represented as a set of threads from different additions, and flows from computers of one enterprise are combined into one stream of a subscriber of some service provider.

Using some methods to provide QoS, in addition to providing a guaranteed quality of services, allows you to efficiently use the network resources.

There are such methods of quality assurance:

4. Setting research objectives

As already mentioned, the main goal of a multiservice corporate network is to facilitate and accelerate the exchange of information within the enterprise, as well as between the enterprise and other business structures.[7] In this case, the use of the network should be justified and constitute the smallest item of expenditure. Having considered the principles of building corporate networks, their architecture, as well as the properties and conditions of traffic transmission, we come to the conclusion that the most costly element of the network is the transport network. Such a conclusion was made considering the following properties of this element:

Non-optimized projects of digital systems, regardless of the basis of implementation, can have a significant redundancy and, therefore, Inefficient use of hardware resources. This leads to the actualization of the task of hardware optimization, which, in the context of FPGA, is reduced to a decrease in the percentage of use of certain internal units: LUT-elements (LUT-Look-Up Table), memory modules, synchronization schemes.

Thus, it is very important to efficiently use the available resources of the enterprise when designing, and to increase the efficiency of the transport network.

Increasing the efficiency of the transport network is possible due to the optimal use of several communication channels between the networks of branches of the enterprise with different characteristics and cost of operation. The solution to this problem can be a border router, which is a link between the branch network and the transport network.

The idea of using an edge router is as follows: in real time, the router analyzes the status of each of the available transport network links at specific times and distributes the information flows depending on the quality of service, the cost of transmission is required.

5. The final goal of the research

The purpose of the research: minimizing the cost of operating the transport segment of the corporate network while maintaining the quality of service by developing an algorithm for the distribution of data streams depending on traffic parameters and characteristics of communication channels.

Conclusion

In this paper, we examined the basic principles of building and the composition of multi-service corporate networks, data streams that are transferred to them. Also, ways to increase the efficiency of using the transport segment of the corporate network were considered.

References

  1. Docuchaev V.A., Lopatina E.V., Timofeeva L.N. (2004). Corporate communication on the basis of IP-telephony: the problem of choice. Vestnik svyazi. no. 11, pp. 59-67.
  2. Хелеби С., Мак-Ферсон Д. Принципы маршрутизации в Internet. 2-е издание, Москва-Санкт-Петербург-Киев, 2001. Режим доступа: http://muff.kiev.ua/files/books/Routing_Internet.pdf
  3. ITU-T: General principles and general reference model for Next Generation Networks. REC-Y.2011. Режим доступа: https://www.itu.int/rec/T-REC-Y.2011-200410-I/en
  4. Вишневский В. М. Теоретические основы проектирования компьютерных сетей. – М.: Техносфера, 2003. – 512 с.: ил; Режим доступа: http://mirknig.su/knigi/seti/59289-vishnevskiy-vm-teoreticheskie-osnovy-proektirovaniya-kompyuternyh-setey.html
  5. Новиков Ю. В. Локальные сети. Архитектура. Алгоритмы. Проектирование. Мониторинг и анализ сетей / Новиков Ю. Кондратенко С. В, Уилсон Э. – М. : ЭКОМ, 2000. – 30S с.
  6. Сторожук Д. О. Методы и алгоритмы для систем мониторинга локальных сетей / Сторожук Д. О. – М., 2008. – 121 с. Режим доступа: http://www.dslib.net/sys-analiz/metody-i-algoritmy-dlja-sistem-monitoringa-lokalnyh-setej.html
  7. Las kin N.. Lamhadaris /.. Harmantzis F. C.. Devetsikiotis M. Fractional Levy motion and its application to network traffic modeling // Elsevier, Computer Networks, 2002. №40. Режим доступа: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.22.5441&rep=rep1&type=pdf
  8. Букатов А.А. Методы распределения емкости телекоммуникационных каналов и обеспечения качества сетевого обслуживания. / Букатов А.А., Шаройко О. В. // Всероссийский конкурсный отбор обзорно-аналитических статей по приоритетному направлению «Информационно-телекоммуникационные системы». – 2008. Режим доступа: http://window.edu.ru/resource/790/58790