Irina Gaskova

ABSTRACT of the Master's Work

"Research and development methodology of modeling processes multiservice telecommunications systems"

Introduction

One of tendencies of development of telecommunication networks is basic change of character and told traffic structure that can be possible to explain prompt growth for quantity of new Internet appendices. Proportions between exist already and again created network services, convergence of telecommunication systems with Internet network.

At the analysis of the corporate networks traffic. Access to the statistics it is possible to tell that the traffic is multimedia, that it is rather uniform distribution of shares of audio-, video- and other types of data flows is traced. Besides, all new algorithms, reports and the technologies directed on improvement of quality of transfer of the traffic of real time in IP-networks constantly are developed and take root.

Such changes complicate in the structure of traffic, and sometimes and eliminate in general, application of analytical design for the created algorithms and processes. An alternative decision an imitation design which allows creating models and terms of work networks most close to reality can serve as.

Actuality

A problem of planning multiservice networks is actual, because of impossibility application for old approaches and known methods.

Informative streams, necessary for the grant of different sort of services in multiservice networks, strongly differentiate on the composition, requirements and volume of necessary network resources. Absence of clear calculation methods for multiservice networks complicates work of designers and prognostication.

Possibilities to physical design at the analysis of networks are strongly limited: it is practically impossible to check up her work for variants with the use of plenty of communication devices  — routers, switchboards; the analysis results differs in calculations complication.

Therefore at an analysis and optimization of networks at planning the use of imitation design appears in many cases preferable. Known application packages, used for planning of multiservice communication networks, in the work directed, as a rule, on the design of network structure, not taking into account here in a due volume important factor of compatibility with an already present equipment and network structure, optimization of economic parameters of the designed network, questions of prognostication of traffic. Thus, development of complex of methods and tools, wrap-round a design and optimization of project decisions at planning of multiservice network, is an actual task. Development of methods of design of planning exactly of multiservice network will help not only in teaching in universities but also application at direct development of projects of such networks will find.

Connection of work with the scientific programs, plans, themes

Qualifying work of master's degree is executed during 2009-2010 pursuant to scientific direction of department of "Automation and telecommunications" of the Donetsk national technical university

Purpose and tasks of development

Purpose of the work:

The purpose of this qualifying work of master's degree is upgrading of planning of multiservice TCNS, choice of optimal decision for the construction of network, decline of expenses on building and exploitation of network.

Idea of the work:

The idea of work is development of recommendations on planning and planning of multiservice telecommunication networks with the use of simulation techniques, on the example of different decisions of construction of the telecommunication systems the criteria of estimation quality of work network are described.

Basic tasks of development:

• research construction process of multiservice communication networks, exposure the basic stages of planning, analysis existent technologies telecommunications networks;
• setting essence and planning problem of multiservice communication networks with the use of telecommunication equipment of different producers;
• Choice criteria estimation of quality construction the designed network with the use imitation design facilities;
• Exposure and decision of design problems, arising up at planning existent decisions construction of networks and at planning of networks with the use of new technologies and methods;
• Choice effective decision network construction with the use of different technologies
• development of complex methods and facilities optimization of different parameters project decisions, such as economic expenses, network performance, routing in the kernel of network and other parameters
• Estimation of efficiency of the accepted project decisions and development of methods of design of planning multiservice networks.

Article of development:
The article of development are methods of design of planning of multiservice TCNS.

Object of working out:

Object of working out is the technique of designing of multiservice networks with use of means of imitating modeling

Methodology and methods of researches:

• Methods of optimization
• Methods of theory of mass service
• Petri nets
• Simulation techniques
• Methods of management the traffic of network

Supposed scientific novelty and practical meaningfulness of the got results:

During implementation works will be certain fundamental principles of design of multiservice networks in the package of design of OPNET and possible purviews of these principles. It is needed to mark that the package of OPNET IT Guru Edition is worked out especially for the academic use, so that the offered methods can be used in the process of teaching in higher educational establishments and at preparation of specialists in the field of telecommunications.

Review of developments and researches on the topic:

At local level

• Chitnikova A. N. Master's degree work. Development methods of estimation parameter of traffic multiservice network.
• Shishkin E. S. Master's Degree work. Cluster system of the up-diffused design of computer networks
• Latorcev A. A. Master's degree work. Development subsystem design of the distributed computer informative systems
• Timonov S. Master's Degree work. Development and research multiservice network of subscriber access on the basis of technology of VoDSL for the terms of CTS Donetsk



At national level

• Olifer N. A., Olifer B. Use of design for optimization of the productivity of network
• Domdrovskiy K. A. Simulation model of transmission of multimedia traffic in a multiservice network with the adaptive routing on the basis of the object-oriented approach: dissertation.
• Luntovskiy A. O. Methodology and tool of planning of corporate ñåòåé: dissertation
• Berkman L. N. Methods and methods of increase of indexes of quality of control system by the telecommunication systems: dissertation.
• Savinkov A. Avtomatization planning of the systems the digital signal processing on the basis of the integrated environment of imitation design of optimization

Raising of problem and feature of passing to the multiservice networks

At planning of multiservice network aim to find such variant of construction of a transport network, which would satisfy a necessary requirement in connection at the least total expenses on a construction, service and subsequent development of network. Planning of main and distributive level can present an intricate problem. It is caused by a few factors: construction of multiservice network over past technical decisions (optimize an old network for maintenance of multiservice traffic), choice of optimal technology construction of network from the ground up. Also at creation and exploitation of any communication of size of capital costs and running expenses network must be minimum on condition that a network executes with the set high-quality indexes the functions laid on her on a transmission and distribution of informative streams, actings from consumers [1].

Quality functioning of telecommunications network is characterized by plenty of technical parameters which conditionally can be divided into parameters internals of transmission of signal and parameters of quality of favour. To the parameters of quality of transmission of signal such indexes behave, foremost, as: latency (delay), jitter (shaking) and packet loss (loss of packages). The favor quality parameters can be unique for different services. Such parameters can be, for example, amount channels of ether video accessible in networks and quality of these channels.

Except for the parameters of functioning quality network her cost, which includes capital costs, and also running expenses, has large importance.

A Multiservice network is characterized by plenty of various criteria, qualificatory her optimality such as: parameter of quality of functioning of network (delay, shaking, loss of packages et al), cost parameters (capital costs, running expenses) It results in the origin of multicriterion vagueness, that, in turn, impossibility of correct decision of task of the optimal planning of multiservice network stipulates without the account of interests of parties, interested in her functioning. The different groups of persons are interested in the high-quality functioning of multiservice network. First of all, it is an operator of network, which invests facilities in building of network and bears expenses on maintenance of her capacity, and consumers of services of connection. And, interests of different groups of consumers and operators of services clash at planning and use of modern multiservice network.

For the high-quality planning of multiservice network the account of all requirements, produced to the network is needed. This task can be decided by means of design to the network, that allows beforehand to plan, define the possible future problems of exploitation and development, test a rightness and possibilities of work of network equipment for the different situations of functioning, to conduct the study of new technologies and mechanisms, and most important due to facilities of imitation design there is considerable cost effectiveness.

As for passing to the multiservice networks, then today yet there are not technologies which fully would satisfy to the queries of perspective multiservice network. However technological decisions, capable to become her basis, exist already now, i.e. it is possible to build the prototype of multiservice network, which in course of time will be able easily to evolve to the multiservice network of the future.

Imitation design

An imitation design is a method of research at which the studied system is replaced by a model with sufficient exactness describing the real system and with her experiments is conducted with the purpose of receipt of information about this system.

To the imitation design come running, when:

• expensive or it is impossible to experiment on the real object;
• it is impossible to build an analytical model, because in the system there is time, causal connections, consequences, to non-linearity, stochastic (casual) variables;
• it is necessary ñûìèòèðîâàòü conduct of the system in time.

An imitation design allows imitating the conduct of the system in time. Thus a plus is that in a model it is possible time to manage: to slow in case with stop-actions and accelerate for the design of the systems with slow changeability. It is possible to imitate the conduct of those objects, real experiments with which roads, impossible or dangerous.

Advantage above other types of design

Application of simulation models gives the great number of advantages as compared to implementation of experiments above the real system and use of other methods.

Cost. The construction of network requires considerable expenses, a design includes the cost of corresponding programmatic package only Time. In reality to estimate efficiency, for example, of new network will occupy years, and if to take into account speed of development of the telecommunication systems, then forecast possibility of change and optimization is initially necessary. A simulation model allows defining the optimality of changes for the counted minutes, necessary for realization of experiment.

Repetition. Modern life requires from enterprises and operators of connection of rapid reaction on development of technologies. By means of simulation model it is possible to conduct the unlimited amount of experiments with different parameters, to define the best variant. Exactness. Traditional calculation mathematical methods require application of high degree of abstraction and important details do not take into account. An imitation design allows describing the structure of the system and her processes in a natural kind, not coming running to the use of formulas and strict mathematical dependences.

Evidentness. A simulation model possesses possibilities of visualization of process of work of the system in time, scheme task of her structure and delivery of results in a graphic kind. It allows evidently presenting the got decision and carrying the ideas stopped up in him to the client and colleagues.

Universality. An imitation design allows to decide tasks from any areas. A model imitates in every case, reproduces, real life and allows to conduct the wide set of experiments without influence on the real objects.

At planning an imitation design can be applied both with the purpose of choice of project decision and with the purpose of verification of the chosen project decision. At the choice of project decision make the plan of imitation experiments, in which the entrance of model are different project decisions, and by an output are indexes of work of object designs, corresponding to the requirement specification.

Review of facilities of imitation design

BONeS (firm Systems and Networks) is the graphic system of design of the general setting for the analysis of architecture of the systems, networks and protocols. Describes models at transport level and at the level of appendixes. A client enables analysis of influence of appendixes of type is a server and new technologies to work of network.

Netmaker (firm OPNET Technologies) is planning of topology, facilities of planning and analysis of networks of wide class. Consists the different modules for a calculation, analysis, planning, visualization, planning and analysis of results.

Optimal Perfomance (firm Compuware Optimal Networks) - has possibilities of rapid evaluation and exact design, helps to optimize the up-diffused software.

Prophesy (company Abstraction Software) is the simple system for the design of local and global networks. Allows estimating time computer reaction upon request, amount of "hits" on WWW-server, the work stations for maintenance of active equipment, supply of network performance at breakage of certain equipment.

Family of CANE (company ImageNet) the planning of the computer system, estimation of different variants, scenarios "that, if". Design on the different levels of model of OSI. Developed library of devices, which includes physical, electric, temperature and other descriptions of objects. Creation of the libraries is possible.

Family of OPNET (firm OPNET Technologies) is a mean for planning and design of local and global networks, computer systems, appendixes and distributed systems. Possibility of import and export of data about a topology and network traffic. Analysis of influence of appendixes of type client-server and new technologies to work of network. Design of hieratical networks, multiprotocol local and global networks account of algorithms of routing. Object-oriented approach. Exhaustive library of protocols and objects. Includes next foods: Netbiz (planning and optimization of the computer system), Modeler (design and analysis of the productivity of networks, computer systems, appendixes and distributed systems), IT Guru (estimation of the productivity of communication networks and distributed systems). In hired the package of OPNET IT Guru Edition is used. A choice is conditioned, foremost, that this package is in free distribution, because was worked out specially for the academic use. In addition, he is the industrial powerful design of networks and analysis of instruments.

OPNET IT GURU allows:

• to create a virtual network, consisting of corresponding vehicle facilities, protocols, and also application software;
• it is a programmatic interface which can work on an individual workplace cleanly;
• allows to study and collect useful statistics about a virtual network, built with his help;
• to create to the virtual network in area of software, and also gives instruments for dinamically gainings information about a network.

Description of technology, used for the construction of multiservice network

The successful choice of principle of construction and direction of development of network can substantially influence on the long-term prospect of activity of any modern enterprise. Exactly these enhance able interest is explained to technologies of construction of the universal multiservice systems which are able to provide a grant or receipt of all complex of informative services. If to examine modern tendencies construction of networks of main level, then leading positions are occupied by technology of MPLS, passing ATM and SDH.

Main dignity of MPLS is multi-variant approach of the use, and from the point of view of today's situation with the grant of services, similar possibilities very interesting operators.

We will consider bases of functioning of technology.

The basic difference of this technology became already a long ago well-known  — IP-routers analyzes heading of every package, to choose direction for his sending to the next router, in technology of MPLS heading analysed only one time on a netn logon MPLS, set whereupon accordance between a package and stream.

Principle of commutation of MPLS is based on the exchange of marks

Any transferrable a package is associated with one or another class of network layer of FEC (Forwarding Equivalence Class), each of which is identified by a certain mark.

The value of mark is unique only for the area of way between the nearby knots of network of MPLS, which are named also routers, commutation on the marks of LSR (Label Switching Router). On the fig. 1 principle of commutation is shown where a boundary router of LSR1 is an entrance, and LSR4 is an output router. The sequence of routers (LSR1,.., LSR4), which packages, belongings one FEC, pass through, forms the virtual highway of LSP, commutation on marks, LSP (Label Switching Path).

Entrance LER analyses heading of coming from outside package, sets, what FEC he belongs, provides with this package a mark which is appropriated this FEC, and sends a package to corresponding LSR. Further, passing in general case through a few LSR, a package gets to the weekend of LER, which deletes a mark from a package, analyses heading of package and sends it to the addressee, to being outside MPLS -network.

The sequence (LERin, LSR1, .., LSRn, LERout) of routers, which packages, belongings one FEC, pass through, forms the virtual êîììóòèðóåìûé on marks highway of LSP (Label Switched Path). Because the same LER for one streams is an entrance, and for other - by a weekend, in a network, containing N LER, in simplest case can exist N(N - 1) FEC and, accordingly, N(N - 1) LSP.

Figure 2.  — Principles of MPLS commutation

Guarantee QoS

In MPLS -ñåòÿõ on the base of marks a transmission with the quality guarantee of service of network (QoS) will be realized comfortably. Inwardly MPLS- domain transmission of different flows of data is absolutely safe due to their clear logical division. For the increase of reliability the functions of Fast Reroute and LSP Protection are realized in technology of MPLS, which allow beforehand to create the duplicate routes of commutation and in the case of death basic way to pass to the reserve route without the loss of transferrable data.

Introduction and maintenance of networks of MPLS is more compatible and simplified as compared to ordinary IP -ñåòÿìè due to the use of protocols of LDP and RSVP. First from them intended for the automatic laying of new ways in MPLS-domain. Protocol of RSVP allows managing distribution of carrying capacity between virtual circuits in a network, providing the assured required level of quality of service.

A design of network of MPLS is in OPNET

The model in the environment of modeling is collected, is shown in figure 3.

Options of the equipment and the network traffic have been made for the given network, modules LSR are besides adjusted, parameters FEC are configured, is created two profiles of users for tracing multimedia. The received results are presented in figure 4.

Figure 4.  — Results of modeling

Direction of further development:

Creation of methods of design of planning of multiservice networks for different variants construction of network, implementation of the methodical pointing on laboratory works in the environment of design of OPNET for the students of specialty telecommunication systems and networks.

Conclusions:

In there were describing motion of work basic problems of planning of multiservice communication networks, chosen facilities of imitation design, the review programming foods and design methods is produced, on the basis of analysis as a package further researches will be produced in which, OPNET IT Guru Edition is chosen. The example of realization of multiservice network is considered on the base of technology of MPLS in this package.

Literature:

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Note

When writing this autosummary master work was not yet completed. The final completion on December 10, 2010. Full text of the work and materials on the topic can be obtained from the author or his manager after that date.