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1

Influence of Self-Similar Traffic Type on Performance of QoS Routing Algorithms

Czarkowski M., Kaczmarek S., Wolff M.

International Journal of Electronics and Telecommunications

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2016

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Vol. 62, No. 1

81--87

EN

Providing a Quality of Services (QoS) into current telecommunication networks based on packet technology is a big challenge nowadays. Network operators have to support a number of new services like voice or video which generate new type of traffic. This traffic serviced with QoS in consequence requires access to appropriate network resources. Additionally, new traffic type is mixed with older one, like best-effort. Analysis of these new and mixed traffic types shows that this traffic is self-similar. Network mechanisms used for delivery of quality of services may depend on traffic type especially from the performance point of view. This paper presents a feasibility study done into the effect of traffic type influence on performance of routing algorithm while the routing algorithm is treated as one of the mechanisms to support QoS in the network.

2

Traffic type influence on performance of OSPF QoS routing

Czarkowski M., Kaczmarek S., Wolff M.

Journal of Telecommunications and Information Technology

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2013

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nr 3

19--28

EN

Feasibility studies with QoS routing proved that the network traffic type has influence on routing performance. In this work influence of self-similar traffic for network with DiffServ architecture and OSPF QoS routing has been verified. Analysis has been done for three traffic classes. Multiplexed On-Off model was used for self-similar traffic generation. Comparison of simulation results was presented using both relative and non-relative measures for three traffic classes. Results were commented and analyzed. The basic conclusion is that performance for streaming and best-effort class for self-similar traffic is higher than performance for the same class with exponential traffic (Poisson). The other important conclusion is relation between performance differences and offered traffic amount.

3

Simulation model for evaluation of QOS routing algorithm in large packet networks

Czarkowski M., Kaczmarek S., Stępnicki S.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2010

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T. 18

167-172

EN

The variety of traffic transferred via current telecommunication networks includes also voice, which should meet quality requirements. One of mechanisms, which can support QoS in current packet networks, is routing. There exist many routing proposals which should introduce the QoS into the network but practically they don't. Following paper presents the realization of simulation model for evaluation of a new routing algorithm DUMBRA (Dynamic Unattended Measurement Based Routing Algorithm). The proposed algorithm is based on dynamic measurements of differentiated class of serviced traffic and provides mechanisms which introduce QoS when the traffic fluctuations are present in the network. Also load balancing techniques have been introduced using KSP (K-shortest path) algorithm for utility optimization. The simulation model has been implemented in Omnet++ and results have been performed for many different network topologies. Selected results are presented.

PL

Wielka różnorodność ruchu przesyłanego w obecnych sieciach telekomunikacyjnych zawiera w znacznej mierze przenoszenie pakietów dla usług typu mowa, które powinny spełniać wymagania QoS. Jednym z mechanizmów, który może wspierać QoS w obecnych sieciach pakietowych jest ruting. Istnieje wiele propozycji na działanie tego mechanizmu, jednak praktycznie żadna z nich nie gwarantuje QoS. Zaprezentowany artykuł przedstawia realizację modelu symulacyjnego do weryfikacji propozycji nowego algorytmu rutingu DUMBRA (ang. Dynamic Unattended Measurement Based Routing Algorithm). Zaproponowany algorytm działa w oparciu o pomiary sieci i zapewnia QoS również w czasie zmian charakteru ruchu. Zawiera on również mechanizmy równoważenia obciążenia zasobów za pomocą algorytmu KSP (ang. K-shortest path). Model zrealizowano w oparciu o symulator Omnet++ i za jego pomocą przebadano wiele różnych topologii sieci. W artykule, z uwagi na ograniczoną objętość, Zaprezentowano i omówiono wybrane wyniki badań.

4

Simulation model for evaluation of packet sequence changed order of stream in DiffServ network

Czarkowski M., Kaczmarek S.

Advances in Electronics and Telecommunications

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2010

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Vol. 1, no. 2

30--34

EN

Current packet networks use a large variety of mechanisms which should support QoS (Quality of Service). One of those mechanisms is routing (calculating connection paths for incoming service requests). The most effective mechanism in QoS context is dynamic routing, based on the current network state described by the offered traffic matrix and link states. After switching between calculated available paths, connection path changes may cause received packets to change order within a single stream. This paper includes the problem definition and the analysis of all additional effects. A combined simulation/analytic model was proposed in order to answer whether the number of changed-order packets is significant and if it should be considered when calculating the end-to-end delay balance in analytical models for packet networks with differentiated services. Furthermore, the proposed model gave the answer on how often calculated paths may be switched to avoid the network beingout of tune.

5

System wspierający testowanie platform telekomunikacyjnych czasu rzeczywistego

Czarkowski M., Kaczmarek S., Kawiak R.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2008

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T. 15

13-18

PL

Publikacja ma na celu omówienie systemu, jaki został stworzony z myślą o testowaniu platform telekomunikacyjnych czasu rzeczywistego. System został zrealizowany jako na narzędzie, które jest w stanie w pełni automatycz-nie wykonywać testy oraz analizować ich wyniki, bez konieczności nadzorowania procesu egzekucji testów. Dokument zawiera opis struktury systemu, opartej na koncepcji agentów softwareowych, która pozwoliła na pełną automatyzację procedury testowej. Szczególna uwaga przywiązana jest przy tym do zastosowania systemu w testach wydajnościowych, jako że w ramach systemu testowego zintegrowano sprzętowe generatory oraz analizatory ruchu, będące w stanie generować oraz analizować w czasie rzeczywistym duże ilości ruchu. Możliwości sys-temu omówione są na przykładzie jego zastosowania w testach wydajnościowych dla Kontrolera Sieci Radiowej RNC (ang. Radio Netwok Controller) w systemie UMTS.

EN

The aim of this paper is to present a test system, which has been created for testing real-time telecommunication platforms. The system has been created as an automate test tool, that can execute and analyze tests without the supervision of the test personnel. This paper describes the design of the tool, which is based on the concept of software agents that allowed achieving full automation of the test procedure. Attention is paid to the system's usage in performance tests, where the test system utilizes hardware traffic generators that can generate vast amount of traffic, simulating data streams from many users, and where hardware traffic analyzers are used for processing this data and providing statistics which are used in the test's analysis. The system has been initially created to conduct performance tests on the Intel's UMTS Radio Network Controller, but its design allowed using it testing other telecommunication platforms.