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Search results for: QOS (QUALITY OF SERVICE)
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Subjective quality evaluation of 8- and 10-bit MP4-coded video sequences from Netflix
PublicationRecently, many researchers have been intensively conducting quality of service (QoS), quality of experience (QoE), and user experience (UX) studies in the field of video analysis. This paper is intended to make a new, complementary contribution to this field. Currently, streaming platforms are key products in relation to delivering video content online. Most often, they include the MP4 video format, which is most widely utilized...
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Practical issues for the implementation of survivability and recovery techniques in optical networks
PublicationFailures in optical networks are inevitable. They may occur during work being done for the maintenance of other infrastructures, or on a larger scale as the result of an attack or large-scale disaster. As a result, service availability, an important aspect of Quality of Service (QoS), is often degraded. Appropriate fault recovery techniques are thus crucial to meet the requirements set by the Service Level Agreements (SLAs) between...
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Attempt to a Video-Transmission Capability in MV Mine Cable Network Using BPL-PLC Technology
PublicationThis article presents and discusses the attempt to transmit video content using the BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It includes simulation results of a specially developed digital transmitter and receiver, dedicated to a given predefined 6 kV mining power cable. The effect of two different transmission modes (2-7 MHz and 3-7.5 MHz) and two types of coupling (capacitive-inductive and induction-inductive),...
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Messmethoden zur beurteilung der qualität von VoIP-verbindungen
PublicationPraca jest poświęcona tematyce QoS (Quality of Service) w sieciach IP. Na początku pracy opisano i porównano standaryzowane metody oceny jakości połączeń telefonicznych, tzn. MOS, PAMS, PSQM, PESQ, 3SQM, E-Modell. Następnie przedstawiono nowy efektywny system pomiarowy TraceView®:VoIP. Przy jego użyciu jest możliwy objektywny pomiar jakości usługi VoIP (Voice over IP) w sieciach IP. System ten umożliwia również dokonanie w...
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Mechanizm dostarczania usług w chmurze: roxzwiązanie NOR-STA
PublicationArtykuł prezentuje mechanizmy udostępniania w chmurze usług rozwijanych w ramach projektu NOR-STA. Są one ukierunkowane na wspomaganie procesów dochodzenia do zgodności i oceny zgodności z normami i standardami. W projekcie NOR-STA prowadzone są obecnie eksperymentalne badania wdrożeniowe we współpracy z partnerami z sektorów ochrony zdrowia i biznesu. Usługi NOR-STA są udostępniane zgodnie z modelem Software as a Service (SaaS)....
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Analiza jakości transmisji treści audio-wideo w symulowanym łączu telekomunikacyjnym z wykorzystaniem techniki OFDM
PublicationWdrożenie niezawodnego systemu komunikacji audio-wideo przynosi wiele korzyści. Z uwagi na fakt, że ilość dostępnego pasma stale się kurczy, badacze koncentrują się na nowatorskich metodach transmisji. Obecnie technika OFDM (Orthogonal Frequency Division Multiplexing) jest szeroko stosowana zarówno w mediach przewodowych, jak i bezprzewodowych. W pracy przedstawiono badania jakości QoS (Quality of Service) symulowanego łącza transmisji...
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Relay-aided Wireless Sensor Network Discovery Algorithm for Dense Industrial IoT utilizing ESPAR Antennas
PublicationIndustrial Internet of Things (IIoT) applicationsrequire reliable and efficient wireless communication. Assumingdense Wireless Sensor Networks (WSNs) operating in a harshenvironment, a concept of a Time Division Multiple Access(TDMA) based WSN enriched with Electronically SteerableParasitic Array Radiator (ESPAR) antennas is proposed andexamined in this work. The utilized...
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Practical Approach to IP Scheduled Throughput Measurements in Dual Connectivity Systems
PublicationIP scheduled throughput defined according to 3GPP TS 36.314 reflects user throughput regardless of traffic characteristics, and therefore has become one of the most important indicators for monitoring Quality of Service (QoS) of the end user in Evolved Universal Terrestrial Radio Access Network (E-UTRAN). However, networks built on a distributed architecture make the above definition impossible to be applied directly due to the...
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Traffic Model of IMS/NGN Architecture with Transport Stratum Based on MPLS Technology
PublicationGrowing expectations for a fast access to information create strong demands for a universal telecommunication network architecture, which provides various services with strictly determined quality. Currently it is assumed that these requirements will be satisfied by Next Generation Network (NGN), which consists of two stratums and includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS) all NGN stratums...
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Ensuring the QoE-Related Fairness to Reduce the User Abandonment Ratio
PublicationThese days, it is quite a challenge for app owners to keep users engaged with an app. Currently, the level of user abandonment is one of the key parameters that application owners are interested in. To meet these challenges, we are conducting an extended study of a previously proposed solution that significantly reduces the abandonment rate of a given application. The investigated solution is based on the methods of fairness using...
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Simulation model for assessment of IMS-based NGN call processing performance
PublicationIn current telecommunications it is assumed that demands of information society for quickly delivered services will be satisfied by Next Generation Network (NGN) architecture, which includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS), proper design and dimensioning of NGN is absolutely necessary, for which appropriate models have to be proposed. As NGN architecture is very complicated, the most...
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Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture
PublicationCurrently is it assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...
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Simulation model of IMS/NGN call processing performance
PublicationIn current telecommunications it is assumed that demands of the information society for quickly delivered services will be satisfied by the Next Generation Network (NGN) architecture, which includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS), proper design and dimensioning of NGN is absolutely necessary, for which appropriate models have to be proposed. As the NGN architecture is very complicated,...
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Call processing performance in multidomain IMS/NGN architecture
PublicationThe Next Generation Network (NGN) architecture, which bases on the IP Multimedia Subsystem (IMS) concept, is a proposition of a telecommunication network dedicated to the needs of the modern information society. The main goal of NGN is to provide Quality of Service (QoS), for which proper network design and dimensioning are necessary. This also requires appropriate traffic models, which should be efficient and not excessively complicated...
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QoS Resource Reservation Mechanisms for Switched Optical Networks
PublicationThe paper regards the problem of resource reservation mechanisms for Quality of Service support in switched optical networks. The authors propose modifications and extensions for resources reservation strategy algorithms with resources pools, link capacity threshold and adaptive advance reservation approach. They examine proposed solutions in Automatically Switched Optical Network with Generalized Multi-Protocol Label Switching...
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Approximation of Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture Using Phase-Type Distributions
PublicationCurrently it is assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...
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Grzegorz Zieliński dr inż.
PeopleAuthor of over 100 scientific publications (both in Polish and English) in the field of service management, entity improvement, including medical entities. Scientific and research interests include areas related to the maturity and excellence of enterprises in various aspects of their activities. He participated in research projects of the National Science Center and projects implemented by international consortia under the European...
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Traffic model for evaluation of call processing performance parameters in IMS-based NGN
PublicationIn the modern world requirements for accurate and fast information distribution are becoming more and more important, which creates a strong necessity for appropriate telecommunication network architecture. Proposition of such an architecture is the Next Generation Network (NGN) concept, which in order to guarantee Quality of Service (QoS), should be correctly designed and dimensioned. For this reason proper traffic models must...
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Modeling a Traffic Remapping Attack Game in a Multi-hop Ad Hoc Network
PublicationIn multi-hop ad hoc networks, selfish nodes may unduly acquire high quality of service (QoS) by assigning higher priority to source packets and lower priority to transit packets. Such traffic remapping attacks (TRAs) are cheap to launch, impossible to prevent, hard to detect, and harmful to non-selfish nodes. While studied mostly in single-hop wireless network settings, TRAs have resisted analysis in multi-hop settings. In this paper...
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Discouraging Traffic Remapping Attacks in Local Ad Hoc Networks
PublicationQuality of Service (QoS) is usually provided in ad hoc networks using a class-based approach which, without dedicated security measures in place, paves the way to various abuses by selfish stations. Such actions include traffic remapping attacks (TRAs), which consist in claiming a higher traffic priority, i.e., false designation of the intrinsic traffic class so that it can be mapped onto a higher-priority class. In practice, TRAs...
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Service-based Resilience for Embedded IoT Networks
PublicationEmbedded IoT networks are the backbone of safety-critical systems like smart factories, autonomous vehicles, and airplanes. Therefore, resilience against failures and attacks should be a prior concern already in their design stage. In this study, we introduce a service-based network model as an MILP optimization problem for the efficient deployment of a service overlay to the embedded network by meeting QoS and resilience requirements....
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Application tool for IP QoS network design
PublicationDespite the fact that differentiated-service-aware network implementation has been a widely discussed topic for quite some time, network design still proofs nontrivial. Well developed software could put an end to network designer's problems. This chapter describes work, which has been aimed at creating a comprehensive network design tool, offering a fair range of functionality and high reliability. The presented tool is able to...
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QoS/QoE in the Heterogeneous Internet of Things (IoT)
PublicationApplications provided in the Internet of Things can generally be divided into three categories: audio, video and data. This has given rise to the popular term Triple Play Services. The most important audio applications are VoIP and audio streaming. The most notable video applications are VToIP, IPTV, and video streaming, and the service WWW is the most prominent example of data-type services. This chapter elaborates on the most...
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Double-Blind Reputation vs. Intelligent Fake VIP Attacks in Cloud-Assisted Interactions
PublicationWe consider a generic model of Client-Server interactions in the presence of Sender and Relay, conceptual agents acting on behalf of Client and Server, respectively, and modeling cloud service providers in the envisaged "QoS as a Service paradigm". Client generates objects which Sender tags with demanded QoS level, whereas Relay assigns the QoS level to be provided at Server. To verify an object's right to a QoS level, Relay detects...
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Traffic Type Influence on QoS Network Performance of Streaming Traffic Class
PublicationFeasibility study on QoS routing proved that the traffic type influence the network performance. The performance is defined here as a number of packets serviced by the network. In the paper additional element - buffers lengths used in service system was verified in terms of dependencies with routing performance. We present results obtained by simulation for many simulation scenarios. Analysis was done for two different network...
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Tomasz Korol dr hab. inż.
PeopleEducation Gdańsk University of Technology, Faculty of Management and Economics (2001) University of Applied Sciences Stralsund (1999) Degree / scientific title Habilitation – Gdańsk University of Technology, Faculty of Management and Economics (2015) Ph.D. – Gdańsk University of Technology, Faculty of Management and Economics (2004) Employment Gdańsk University of Technology - associate professor (since 2017); assistant professor...
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Opóźnienie efektywne i jego zastosowanie do sterowania ruchem w sieciach pakietowych
PublicationW rozprawie doktorskiej przeanalizowano problem zapewnienia gwarancji jakości usług (Quality of Service, QoS) w sieciach pakietowych, ze szczególnym uwzględnieniem usług o ściśle określonych wymaganiach opisujących opóźnienie pakietów i jego zmienność w sieciach z agregacją strumieni, takich jak np. sieć IP QoS z Differentiated Services (DiffServ) realizująca schemat obsługi Expedited Forwarding Per Hop Behavior (EF PHB) lub sieć...
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Mateusz Muchlado dr
PeopleMateusz Muchlado - assistant professor at the Department of Management and Quality Engineering. He obtained a doctoral degree in management and quality sciences in 2020 at the Faculty of Management and Economics of the Gdańsk University of Technology, defending his thesis entitled "Outsourcing in selected medical entities of the Pomeranian Voivodeship". Associated with the Gdańsk University of Technology since 2010, a graduate...
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Bożena Kostek prof. dr hab. inż.
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Międzynarodowa Konferencja Naukowa w Sopocie
EventsTrzecia z cyklu Międzynarodowa Konferencja Naukowa organizowana przez Katedry Zarządzania z PG oraz UG, która odbędzie się w dn. 19–20.09.2019 r. w Sopocie.
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Piotr Grudowski dr hab. inż.
PeopleProfessor Dr hab. Eng. Piotr Grudowski heads the Department of Quality and Commodity Management at the Faculty of Management and Economics of Gdansk University of Technology. In the years 1987-2009 he worked at the Faculty of Mechanical Engineering of the Gdansk University of Technology, where he obtained a doctoral degree in technical sciences in the discipline of construction and operation of machines and he headed the Department...
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Jakość usług w optycznej sieci wielodomenowej z hierarchiczną strukturą płaszczyzn sterowania
PublicationW rozprawie przedstawiono przegląd architektur sieci z gwarancją jakości klas usług oraz stan prac w zakresie realizacji optycznych sieci ASON, GMPLS oraz ASON/GMPLS. Opisano wymagania i zaawansowanie prac w realizacji sieci ASON/GMPLS z hierarchiczną strukturą płaszczyzn sterowania oraz problemy związane z zagadnieniem jakości klas usług w tej sieci. Zaprezentowano założenia, koncepcję oraz realizację modelu symulacyjnego optycznej...
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JAKOŚĆ USŁUG W ARCHITEKTURZE SIECI ASON/GMPLS A MECHANIZMY REZERWACJI ZASOBÓW
PublicationW artykule przedstawiono mechanizmy rezerwacji zasobów w architekturze sieci ASON/GMPLS, która spełnia wymagania nowoczesnych sieci optycznych, a jednocześnie umożliwia sterowanie siecią z gwarancją jakości usług. W artykule porównano dwa mechanizmy rezerwacji zasobów z gwarancją jakości i podejściem typu POOL. Efektywność prezentowanych mechanizmów zweryfikowano metodą symulacji komputerowej w środowisku OMNeT++.
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Sterowanie optyczną siecią wielodomenową z hierarchiczną strukturą płaszczyzn sterowania
PublicationW artykule przedstawiono problem sterowania wielodomenową siecią optyczną z hierarchiczną strukturą płaszczyzn sterowania. Autorzy proponują wykorzystanie koncepcji sieci ASON/GMPLS, która spełnia wymagania nowoczesnych sieci optycznych, a jednocześnie umożliwia sterowanie wielodomenową siecią z gwarancją jakości usług. W artykule zaproponowano algorytm sterowania z gwarancją jakości, którego efektywność zweryfikowano metodą symulacji...
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Metaheuristic algorithms for optimization of resilient overlay computing systems
PublicationThe idea of distributed computing systems has been gaining much interest in recent years owing to the growing amount of data to be processed for both industrial and academic purposes. However, similar to other systems, also distributed computing systems are vulnerable to failures. Due to strict QoS requirements, survivability guarantees are necessary for provisioning of uninterrupted service. In this article, we focus on reliability...
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Wybrane elementy logistycznej obsługi klienta
PublicationMarketing relacji zakłada wynegocjowaną obietnicę obsługi, która na rynku transportu miej-skiego oznacza pewność zrealizowania usługi przewozowej dla określonego pasażera, w danej relacji, danym środkiem transportu, po określonej cenie, w oczekiwanych warunkach przewozu i w założonym przez organizatora transportu zbiorowego czasie. Uniwersalność zasad obsługi klienta powoduje, że Zarząd Komunikacji Miejskiej w Gdyni od początku...
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Efekty egoistycznych ataków na poziomie mac w sieciach ad hoc o topologii wieloskokowej
PublicationStacje sieci ad hoc mogą manipulować parametrami dostępu do medium transmisyjnego dla osiągnięcia nienależnie wysokiej jakości usług. Dla środowiska sieci ad hoc o topologii wieloskokowej rozważane są ataki na mechanizmy odłożenia transmisji i klasyfikacji ruchu, przeprowadzane zarówno w stosunku do przepływów źródłowych jak i tranzytowych. Wyniki pozwalają wstępnie ocenić efekty takich ataków oraz skuteczność mechanizmów obronnych.
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Service and service decomposition model - theoretical foundation of it service management
PublicationThe publication contains different definitions of Service - one of the fundamental IT Service Management term. It describes types of Service attributes nad introduces so-called ''distinguish functions'' in order to propose different categories of Services. It proposes both general model of Service decomposition and practical model based on CMDB implementation limitations. In summarizes obtained results and gives some remarks about...
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EMULACJA ŚRODOWISKA DLA ZASTOSOWANIA PROTOKOŁU IN-BAND NETWORK TELEMETRY
PublicationOkreślenie jakości obsługi strumieni pakietów w sieci przełączników wymaga odpowiedniego środowiska badawczego w którym prowadzi się doświadczenia i pomiary wybranych wielkości. Protokół In-band Network Telemetry jest jednym z narzędzi, które można wykorzystać do realizacji tych zadań. W pracy zaproponowano zwirtualizowane środowisko badawcze w którym można emulować sieć przełączników programowalnych w języku P4 wraz z implementacją...
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Influence of Self-Similar Traffic Type on Performance of QoS Routing Algorithms
PublicationProviding 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...
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QoS Extensions for Flow-Awareness Networks
PublicationThe paper contains a description and research results of the proposal for distributed QoS extensions for Flow-Based Networking. These QoS extensions let the network accept or reject flows based on current network load and QoS promises for each of the flows. Proposed solution consists of two distributed components, each of them performing in every node, measurement system and access control. The solution could be applied in any...
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QoS w lokalnych sieciach bezprzewodowych.
PublicationZaprezentowano dwa najpopularniejsze obecnie rozwiązania lokalnych sieci bezprzewodowych (Wireless LAN - WLAN). Zarówno sieci standardu IEEE 802.11 jak i ETSI HIPERLAN/2, są postrzegane jako istotne elementy systemów łączności bezprzewodowej czwartej generacji (4G). Ze względu na ograniczoną szerokość pasma radiowego, w sieciach tych niebagatelną rolę zaczynają odgrywać mechanizmy dopasowujące jakość obsługi (QoS) do wymagań aplikacji...
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QoS w lokalnych sieciach bezprzewodowych
PublicationZaprezentowano dwa najpopularniejsze obecnie rozwiązania lokalnych sieci bezprzewodowych (Wireless LAN - WLAN). Zarówno sieci standardu IEEE 802.11, jak i ETSI HIPERLAN/2, są postrzegane jako istotne elementy systemów łączności bezprzewodowej czwartej generacji (4G). Ze względu na ograniczoną szerokość pasma radiowego, w sieciach tych niebagatelną rolę zaczynają odgrywać mechanizmy dopasowujące jakość obsługi (QoS) do wymagań aplikacji...
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Ruting QOS w sieciach NGN
PublicationZnaczna różnorodność usług dostępnych w dzisiejszych sieciach pakietowych wymaga architektur wspierających różnicowanie tych usług, przy jednoczesnym gwarantowaniu jakości usług (QoS). Zapewnienie QoS osiągnąć można jedynie poprzez zastosowanie efektywnych mechanizmów zarówno na poziomie obsługi pakietów jak i strumieni. Jednym z bardzo istotnych mechanizmów na poziomie pakietów jest wyznaczanie dróg połączeniowych. Jest to proces...
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Simulation model for evaluation of QoS routing algorithm in large packet networks
PublicationThe 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...
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Traffic Type Influence on Performance of OSPF QoS Routing
PublicationFeasibility 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 were presented using both relative and...
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Current mechanisms of IGP routing - expectations and possibilities in terms of QoS constraints
PublicationOd mechanizmów rutingu oczekuje się nowych możliwości z chwilą wprowadzenia wymagań QoS. W tym kontekście aktualne techniki rutingu IGP nie oferuja rozwiązań określających ścieżki gwarantujące QoS. W pracy przedstawiono propozycję rozszerzenia OSPF, które umożliwia uwzględnienie ograniczeń wynikających z QoS, gwarantując jednocześnie usługi na żądanym poziomie. To rozszerzenie zawiera zarówno liniowe jak i nieliniowe metryki. Wartości...
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Traffic Type Influence on Performance of OSPF QoS Routing
PublicationFeasibility 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...
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Simulation model for evaluation of QOS dynamic routing
PublicationCurrent informational networks use a large variety of technologies to support data exchange. Most of them are focused on IP protocol and include mechanisms which by definition should supply demanded QoS. One of those mechanisms is efficient path calculation - routing. Traffic offered to the network can change very rapidly in short term. Routing should support such traffic changes and all the time calculate valid paths in terms...
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