Made available in DSpace on 2014-06-12T15:59:17Z (GMT). No. of bitstreams: 2 arquivo4992_1.pdf: 465621 bytes, checksum: beb55c17d095bd73e42ae404d38057fa (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2002 / A crescente demanda e o explosivo crescimento da Internet está impondo novos desafios para a garantia de serviços em termos de performance, confiabilidade e Qualidade de Serviço (QoS). Muitas aplicações de missão crítica que dependem das tecnologias de rede não podem funcionar sem garantias expressas de entrega. Entretanto, as redes de dados atuais não oferecem nenhuma garantia de que as exigências feitas a nível de serviço possam ser garantidas sem algum tipo de degradação a qualquer hora, do dia ou da noite, a despeito de outros usuários da rede. Para atender essas exigências, a infra-estrutura da rede precisa ser melhorada com novas tecnologias que ofereçam aos operadores de rede ferramentas para controlar o comportamento da mesma. Juntas, as capacidades oferecidas pela Engenharia de Tráfego, pelo MPLS (Multiprotocol Label Switching) e pelo DiffServ possibilitam o controle e o balanceamento de carga na rede necessários à entrega de serviço de acordo com contratos personalizados. Este trabalho apresenta o MPLS associado à Engenharia de Tráfego como solução para o problema de alocação ineficiente dos recursos em uma rede e o conseqüente congestionamento provocado por tal problema. O esquema de encaminhamento de pacotes do MPLS é empregado como estratégia para minimizar o congestionamento ou alternativamente maximizar a utilização dos recursos, através da alocação eficiente dos mesmos, garantindo, num ambiente com diferenciação de serviço, uma melhor Qualidade de Serviço em termos de redução na perda de pacotes, no atraso e na variação de atraso, e no aumento da vazão agregada

Quality of Service (QoS) for IP networks is a set of methods for establishing better and more reliable performance for today's and tomorrow's networks. When transmitting real-time data from such applications as IP telephony, video conferencing and IP broadcasting, it is imperative that the data is transmitted quickly and with even delays. Longer delays mean problems when communicating, varying transfer times means that data packets are delivered too late to be used, or even dropped. As network applications grow more demanding, the networks can not always keep up. Even though a network may offer more bandwidth than needed, disturbances to sound and picture is to be expected because of the competition with other data traffic. QoS can solve many such problems by reserving private channels through a network, or differentiating classes of traffic to prioritise the sensitive data. QoS also contains methods to speed up backbone data transfers by in advance planning complete routes over a network, and avoiding congested or broken connections. This report explains QoS as it stands today, together with suggestions on how it could work for Axis Communications AB. It also presents an experiment to test some QoS methods in a real-time sensitive situation, demonstrating the effectiveness and priceworthiness of QoS. / Quality Of Service (QoS) för IP-nätverk är en uppsättning metoder för att erbjuda garantier i hastighet och pålithlighet för överföringar i IP-nätverk. I takt med att nätverk blir snabbare och att flera former av kommunikation flyttas till IP-nätverk, kommer krav på stabilare och mer pålitliga överföringar. QoS gör det möjligt att använda vanliga datornätverk till att exempelvis ringa och genomföra videokonferanser, applikationer som vanligtvis plågas av bristande kvalité på grund av att nätverkstrafik tappas eller försenas. Denna rapport presenterar nuvarande problem och dess lösningar i form av QoS. För att testa vissa QoS-funktioner och mognaden av Open Source-implementationer för QoS görs tester som även visar effektiviteten och de ekonomiska fördelarna av QoS. / Magnus von Rosen Juryvägen 35 226 57 Lund 046 - 13 89 61 pt98mvo@student.bth.se magnusvr@telia.com

The world has emerged as a global village. Internet has brought an amazing change in the era of modern communications. Demand for multimedia applications and an ever increasing amount of VoIP traffic have increased data rate and bandwidth requirements. It has become a big chal-lenge to provide best quality applications. Traffic engineers are working hard over Internet Protocol (IP) and Routing Protocols (RPs) in order to cope with this challenge. IP networks have offered these services efficiently until now, but there are several issues with IP routing that affect the Quality of Service (QoS). Multi-Protocol Label Switching (MPLS) has emerged as an agile technology which promises effective security together with high speed data delivery. MPLS networks use switching instead of conventional routing. MPLS doesn’t replace existing IP networks, but guarantees instead better QoS in existing IP networks as well as future routing technologies, providing thus a suitable environment for Traffic Engineering (TE). The Class of Service (CoS) architecture provided by MPLS can easily be coordinated with IP QoS mecha-nisms. Traffic can be switched based on resource utilization and network performance instead of using static routing techniques such as selecting a path with least cost, optimizing thus the MPLS network for heavy application at desired quality. / Världen har blivit en global by. Internet har inneburit en fantastisk förändring i en tid präglad av modern kommunikation. Efterfrågan på multimediaapplikationer och en allt större mängd VoIP-trafik har ökat datahastighet och krav på bandbredd. Det har blivit en stor utmaning att ge bästa kvalitet ansökningar. Trafiken tekniker arbetar hårt over Internet Protocol (IP) och routingprotokoll (RPS) för att klara av denna utmaning. IP-nät har erbjudit dessa tjänster på ett effektivt fram tills nu, men det finns flera problem med IP-routing som påverkar Quality of Service (QoS). Multi-Protocol Label Switching (MPLS) har utvecklats till en flexibel teknik som utlovar effektiv säkerhet tillsammans med hög hastighet leverans. MPLS-nätverk används byte istället för konventionella routing. MPLS ersätter inte de befintliga IP-nät, utan garantier i stället bättre QoS i befintliga IP-nät samt framtida routing-teknik, vilket har en lämplig miljö för trafikteknik (TE). Den klass som (COS) arkitektur som MPLS kan enkelt styras med IP QoS meka-nismer. Trafiken kan kopplas grundas på resursutnyttjande och nätverksprestanda istället för att använda statisk routing tekniker som att välja en väg med lägsta kostnad, vilket optimerar därmed MPLS nät för tunga ansökan till önskad kvalitet.

The development of 3G (the 3rd generation telecommunication) value-added services brings higher requirements of Quality of Service (QoS). Wideband Code Division Multiple Access (WCDMA) is one of three 3G standards, and enhancement of QoS for WCDMA Core Network (CN) becomes more and more important for users and carriers. The dissertation focuses on enhancement of QoS for WCDMA CN. The purpose is to realize the DiffServ (Differentiated Services) model of QoS for WCDMA CN. Based on the parallelism characteristic of Network Processors (NPs), the NP programming model is classified as Pool of Threads (POTs) and Hyper Task Chaining (HTC). In this study, an integrated programming model that combines both of the two models was designed. This model has highly efficient and flexible features, and also solves the problems of sharing conflicts and packet ordering. We used this model as the programming model to realize DiffServ QoS for WCDMA CN. The realization mechanism of the DiffServ model mainly consists of buffer management, packet scheduling and packet classification algorithms based on NPs. First, we proposed an adaptive buffer management algorithm called Packet Adaptive Fair Dropping (PAFD), which takes into consideration of both fairness and throughput, and has smooth service curves. Then, an improved packet scheduling algorithm called Priority-based Weighted Fair Queuing (PWFQ) was introduced to ensure the fairness of packet scheduling and reduce queue time of data packets. At the same time, the delay and jitter are also maintained in a small range. Thirdly, a multi-dimensional packet classification algorithm called Classification Based on Network Processors (CBNPs) was designed. It effectively reduces the memory access and storage space, and provides less time and space complexity. Lastly, an integrated hardware and software system of the DiffServ model of QoS for WCDMA CN was proposed. It was implemented on the NP IXP2400. According to the corresponding experiment results, the proposed system significantly enhanced QoS for WCDMA CN. It extensively improves consistent response time, display distortion and sound image synchronization, and thus increases network efficiency and saves network resource.

Currently, a viable solution to provide multicast provision over a multiprotocol label switch with traffic engineering (MPLS-TE) domain is unavailable because of the missing link able to couple multicast traffic distribution with an MPLS-TE enabled network. This is due to the limited or less research investigation that was done in this area. Most of the investigation methods tackle the problem individually such as deploying internet protocol (IP) multicast in a plain network or MPLS domain but without considering a combination of both technologies that is aware of differentiated services requirements. This thesis presents an alternative solution for the multicast differentiated services provision problem over a MPLS-TE enabled network. The approach is exposed and analyzed through a practical solution that was developed within a network simulation environment. The research presented in this thesis orchestrates the already available technologies offered by the multicast protocols suite and differentiated services (DiffServ) aware MPLS-TE that allows applying separately the constraint-based routing and admission control to different classes of services. The novelty and solution of this thesis relies on using MPLS constraint-based routing concepts (e.g.traffic trunks) in order to solve TE issues revealed during multicast traffic distribution.

The main goal of today’s wireless Service Providers (SPs) is to provide optimum and ubiquitous service for roaming users while maximizing the SPs own monetary profits. The fundamental objective is to support such requirements by providing solutions that are adaptive to varying conditions in highly mobile and heterogeneous, as well as dynamically changing wireless network infrastructures. This can only be achieved through well-designed management systems. Most techniques fail to utilize the knowledge gained from previously tested reconfiguration strategies on system and network behaviour. This dissertation presents a novel framework that automates the cooperation among a number of wireless SPs facing the challenge of meeting strict service demands for a large number of mobile users. The proposed work employs a novel policy-based system configuration model to automate the process of adapting new network policies. The proposed framework relies on the assistance of a real-time simulator that runs as a constant background process in order to continuously find optimal policy configurations for the SPs’ networks. To minimize the computational time needed to find these configurations, a modified tabu-search scheme is proposed. An objective is to efficiently explore the space of network configurations in order to find optimal network decisions and provide a service performance that adheres to contracted service level agreements. This framework also relies on a distributed Quality of Service (QoS) monitoring scheme. The proposed scheme relies on the efficient identification of candidate QoS monitoring users that can efficiently submit QoS related measurements on behalf of their neighbors. These candidate users are chosen according to their devices’ residual power and transmission capabilities and their estimated remaining service lifetime. Service monitoring users are then selected from these candidates using a novel user-to-user semantic similarity matching algorithm. This step ensures that the monitoring users are reporting on behalf of other users that are highly similar to them in terms of their mobility, used services and device profiles. Experimental results demonstrate the significant gains achieved in terms of the reduced traffic overhead and overall consumed users’ devices power while achieving a high monitoring accuracy, adaptation time speedup, base station load balancing, and individual providers’ payoffs.

More and more sensitive information is communicated digitally and with thatcomes the demand for security and privacy on the services being used. An accurateQoS metric for these services are of interest both for the customer and theservice provider. This thesis has investigated the impact of different parameterson the perceived voice quality for encrypted VoIP using a PESQ score as referencevalue. Based on this investigation a parametric prediction model has been developedwhich outputs a R-value, comparable to that of the widely used E-modelfrom ITU. This thesis can further be seen as a template for how to construct modelsof other equipments or codecs than those evaluated here since they effect theresult but are hard to parametrise. The results of the investigation are consistent with previous studies regarding theimpact of packet loss, the impact of jitter is shown to be significant over 40 ms.The results from three different packetizers are presented which illustrates theneed to take such aspects into consideration when constructing a model to predictvoice quality. The model derived from the investigation performs well withno mean error and a standard deviation of the error of a mere 1:45 R-value unitswhen validated in conditions to be expected in GSM networks. When validatedagainst an emulated 3G network the standard deviation is even lower.v

The diploma thesis is focusing on middleware layer in distributed systems. It introduces typically used communication protocols and standards operating on this layer. In theoretical part it brings closer look at OMG DDS specification. This part contains fundamental functionalities of this specification along with its architecture blocks. Thesis also describes the RTPS protocol functionality. Existing implementations of OMG DDS standard are described at the end of theoretical part. OpenDDS 3.13 implementation is used in practical part of thesis. It is deployed and tested on various platforms. Next part verifies option of securing RTPS data stream using beta version of OMG DDS Security, which OpenDDS 3.13 implementation contains. Secured and unsecured data flows are being compared. Latency of data stream is also important, especially in distributed systems. DDS system, which measures latency of RTPS stream is created in practical part. Latency of this DDS system can be measured in various configurations. Difference of devices’ performance used in measurements can be clearly seen in latency results where the size of data samples is increasing. Differences of measured latency are also recognizable between reliable and unreliable and secure and unsecure RTPS stream. Part of measurements is made between 2 physical devices with and without an attacker. Type of attack is MITM and it captures RTPS flow, which does not belong to attacking machine.

This thesis deals with data distribution service and is divided into three parts. The first part of this thesis focuses on theoretical knowledge of data distribution service. This section gradually introduces the model used in data distribution service, quality of service and the RTPS protocol, which was specially developed for the needs of data distribution service. The most comprehensive part of the theoretical part deals with security in data distribution service. At the end of the first part of this thesis, selected impelementations of data distribution service are introduced. The second part of this thesis deals with practical use of data distribution service, while OpenDDS implementation is chosen for the practical part. This part initially deals with the design of basic communication scenarios, followed by the design of complex communication scenarios. In the next chapters, within the practical part, the thesis is focused on verifyng security of the data distribution service selected implementation, design of security incidents and their subsequent simulation. Content of the final part of this thesis is the introduction of a tool designed for this thesis, which is used to implement selected types of attacks.

The aim of this thesis is to choose the proper measurement system for evaluating the performance of the LTE mobile networks based on long-term measurements. The thesis describes mobile network LTE, its architecture and introducts the Quality of Service in the LTE. In the next part are studied the known measurement methods and furthermore, there is proposed a solution in the form of long-term measurement. This measurement uses the mobile phone application Open-RMBT, which stores the measurement results into the database on the chosen server. The following part focuses on the issue of choosing a suitable mobile device for the measurement, then it describes a pilot testing and the followed run of the long-term measurements. In the last part is introduced the interractive application to plot graphs. Measurement results are discussed in the conclusion.