Internet has dominated the modern communication and information exchange and it is growing enormously day by day. Initially it is designed to off?er various applications like World Wide Web (WWW), Electronic Mail (E-Mail) and File Transfer (FTP). WWW has become very popular and today, Web traffic constitutes 70-80% in global Internet traffic. Web traffic generates by the end users, when they request for a web page. The web page transfers between various Web servers via different service networks to the end users. Web traffic has become very significant in the present world and the service providers have to offer best service to the customers. Quality of Service (QoS) is a measure of describing the performance of the service. Quality of Experience (QoE) explains the user perceived performance and it is subjective in nature. QoE influences the user satisfaction level, so QoS has to ensure to promote better QoE. User perceived QoE depends on page download time and it is an important parameter in evaluating the performance of web service. In this work we try to correlate the web page download times at both application-level and network-level. In particular, when there is a considerable delay in the network, we tried to correlate the application perceived download time with network-level download time. We explained the difference between application and network download times and how it varies with the applied delay. This work also shows how the download times at both levels are related to each other and their coefficient of correlation. / Internet har dominerat modern kommunikation och informationsutbyte och den växer enormt varje dag. Inledningsvis är det för att stänga? ER olika tillämpningar som World Wide Web (WWW), elektronisk post (e-post) och filöverföring (ftp). WWW har blivit mycket populärt och idag utgör webbtrafik 70-80% i den globala Internet-trafiken. Webbtrafik genererar av slutanvändarna, när de begär för en webbsida. Webbsidan överföringar mellan olika webbservrar via olika tjänsteleverantörer nätverk för slutanvändarna. Webbtrafik har blivit mycket betydande i dagens värld och tjänsteleverantörerna har att erbjuda bästa service till kunderna. Quality of Service (QoS) är ett mått för att beskriva utförandet av tjänsten. Kvalitet på Experience (QoE) förklarar användaren uppfattat utfall och det är en subjektiv karaktär. QoE påverkar hur nöjda användarna, så QoS måste se till att främja bättre QoE. Användare uppfattas QoE beror på sidan ladda ner tid och det är en viktig parameter vid utvärdering av prestanda av webbtjänsten. I detta arbete försöker vi att korrelera webben gånger sidan ladda ner på både program-nivå och på nätverksnivå. I synnerhet när det finns en betydande fördröjning i nätet, försökte vi att korrelera ansökan upplevda tid för nedladdning med nät-nivå nedladdning tid. Vi förklarade skillnaden mellan applikationer och nätverk gånger hämta och hur den varierar med den tillämpade dröjsmål. Detta arbete visar också hur hämtningstider på båda nivåerna är relaterade till varandra och deras korrelationskoefficient.

Le besoin des applications de streaming multimédia en temps réel sur Internet ne cesse d’accroître. Dans ce contexte, les réseaux Pair-à-Pair (P2P) jouent un rôle prépondérant afin d’assurer une transmission robuste et extensible (scalable) de contenu multimédia à grand-échelle. Cependant, le déploiement des applications de streaming multimédia à travers les réseaux P2P présente plusieurs verrous. En effet, les applications de streaming vidéo nécessitent une garantie de performances temps réel en termes de : délai minimal de bout-en-bout, faible taux de perte de paquets et garantie de la bande passante. Par ailleurs, un réseau P2P est composé d’un ensemble de terminaux interconnectés à travers des réseaux hétérogènes, n’ayant pas forcément les mêmes caractéristiques requises afin d’offrir la même qualité vidéo aux clients finaux.Dans cette thèse, nous analysons différents problèmes liés au streaming en-direct (Live) ou à la demande (VoD) de la vidéo sur les réseaux P2P, et nous proposons un ensemble de mécanismes pour y remédier. / There is an increasing demand for efficient deployment of real-time multimedia streaming applications over Internet. In this context, Peer-to-Peer (P2P) networks are playing an important role for supporting robust and scalable transmission of multimedia content to large-scale and massive receivers. P2P networks consist of different heterogeneous networks and devices, which may not have symmetric characteristics to offer the same video quality to end clients. The deployment of streaming applications such as live and on-demand over P2P networks is challenging. Indeed, video streaming applications require real-time performance guarantee in terms of low end-to-end delay, low packet loss and guaranteed available bandwidth. Moreover, P2P video streaming also experiences the problems of long start-time and churn-induced instability. The situation leads to affect the viewing experience of the users in P2P networks.The aim of this thesis is to analyze these issues and to propose quality-aware mechanisms for both live and on-demand streaming over P2P networks. Our contributions in this dissertation are threefold. First, we propose a small world overlay organization mechanism allowing efficient organization of peers to reduce the end-to-end delay for live streaming applications. Second, we propose a mechanism for cooperative prefetching with differentiated chunks scheduling suitable for P2P video-on-demand (VoD) to efficiently handle seek operations while reducing the response latency and increasing the hit ratio. Finally, we present a smoothing mechanism for layered streaming in P2P networks. The mechanism aims to reduce the number of layer changes under varying network conditions while at the same time achieving a high delivery ratio.

Jönköping Energi AB (JEAB) is a local energy supplier for the county of Jönköping. JEAB also maintain the local Metropolitan Area Network (MAN). They have recently installed GPON in a portion of their network and have connected it to the MAN via an Extreme switch. However JEAB would prefer to use Cisco equipment instead of Extreme since the MAN comprises of Cisco hardware. They require a solution to connect GPON to the MAN with a recently purchased line card (Cisco 7600 ES20) which can be installed in a Cisco 6500 Catalyst switch. There is also a possible solution with an Alcatel-Lucent 7450 ESS-1 switch. The proposed solution is to use Virtual Private LAN Service (VPLS), though the exact implementation required is unknown. Additionally JEAB have asked for research into GPON and VPLS in order to improve their understanding of both techniques. This would be of benefit to them both now and in the future. In order to achieve the stated objectives the following questions are raised: • How does GPON work? • How does VPLS work? • How can GPON be connected to the MAN via Cisco Systems 6500 Catalyst switch/7600 Router? • How can GPON be connected to the MAN via Alcatel-Lucents 7450 ESS-1? The research into GPON and VPLS provides the required background knowledge in order to investigate how GPON can be connected to the MAN. The main body of the work is to analyse the requirements of the company and build a configuration which satisfies them. The desired implementation via Cisco Systems solution was deemed unsuitable due to a feature of DHCP option 82 which did not function as required. The focus then turned to Alcatel-Lucents solution. The resulting solution uses a part of VPLS via Alcatel-Lucents 7450 ESS-1. All the key elements are included, including hiding customer VLANs from the ISP and per-service QoS bandwidth management. The conclusion is that whilst using Alcatel-Lucents solution means a deviation from the all-Cisco implementation that had been planned; the benefit of including all the desired functionality outweighs the mixing of manufacturers. The techniques of GPON and VPLS are extremely versatile and can be used in a variety of networks. Therefore there is scope for further research into how these two techniques can be used together in other types of MAN.

Avsikten med detta arbete har varit att undersöka huruvida någon prestandaskillnad föreligger mellan nätverksnodernas vidarebefordring av prioriterad trafik i en nätverksmiljö med Quality of service-funktioner (QoS) implementerade och nätverksnodernas arbete i samma nätverksmiljö med separata, virtuella nätverk uppsatta med hjälp av Virtual routing and forwarding (VRF). Målet var att resultatet ska ha möjlighet att väga in när för- och nackdelar mellan olika sätt att separera nätverkstrafik jämförs ur prestandasynpunkt. Rapporten beskriver arbetet med samt resultatet av ett empiriskt experiment som kontrollerade VRF:ers påverkan på QoS-funktioner. Ett fysiskt nätverk sattes upp för att kontrollera hur QoS påverkades av logisk separering av experimentmiljöns nätverk på lager tre med hjälp av VRF. I detta nätverk utfördes även ett kontrollexperiment utan logisk separation för att skapa en baseline samt ett experiment där separering utfördes med hjälp av accesslistor. För varje experimentfas skickades en videoström genom experimentmiljön för att mäta End to end delay, Packet loss och Jitter, samt webbside requests för att upp mäta Round trip time. Detta testförfarande utfördes tre gånger per experimentfas.   I experimenten kunde ingen Packet loss uppmätas vilket tyder på att QoS fungerade som avsett, även med VRF. Vissa förändringar för nätverksnoderna behövde genomföras beroende på teknik, vilket gjorde att det blev svårt att dra en slutsats av resultaten för End to end delay, Jitter och Round trip time.

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Video streaming through IP networks has risen rapidly over the recent years, and will continue to do so over the coming years. In addition to this, new technologies such as Virtual Reality and robotics will lead to many new applications that will put high pressure on the networks. To combat these challenges, networks need to be application sensitive, and be able to provide Quality of Service (QoS) based on requirement. Network paradigms like Software Defined Networking (SDN) enables the network to be directly programmable, and could thus solve the challenge. In this thesis, the objective is to research if SDN can provide High QoS. Methods are developed to achieve High QoS with SDN. A combination of Differentiated Services Code Point (DSCP) values and DSCP remarking with Meters are used enable High QoS and together they can give bandwidth guarantee. As a result of the thesis, a solid theoretical method is provided for achieving QoS, tests are performed and show that QoS can be implemented in SDN, but it is unable to implement High QoS due to the lack of implementation for Meters with DSCP remarking.

[pt] Este trabalho enfoca os efeitos provocados pelas características auto-similares do tráfego agregado na gerência de redes de serviços integrados. Para isso, disciplinas de serviço,mecanismos essenciais para o controle de congestionamento em uma rede, foram implementadas, fontes de tráfego, elementos a serem gerenciados, foram utilizadas e análises de desempenho realizadas quando estas fontes compartilham uma rede. Adicionalmente, este trabalho mostra por meio de simulações as garantias e propriedades fornecidas por tais disciplinas. / [en] This work concerns on the effects caused by the traffic self-similar characteristics aggregated in the management of the networks´ services. With this objective, service disciplines, which are essential mechanisms used to control networks` congestion, were implemented; traffic sources, which are elements to be managed, were used; and performance analysis were developed when all the sources shared the network. Furthermore, this work shows through simulations the guarantees and properties provided by the disciplines.

Les accidents de la circulation sont un des plus grands problèmes de sureté publique. Par conséquent la sécurité routière a toujours été la principale préoccupation des acteurs de la sécurité des transports. Durant les dernières décennies, les pouvoirs publics et les entreprises du secteur automobile ont été impliqués dans l'amélioration de nos systèmes de transport de la sécurité en réduisant les conséquences des accidents imminents et en diminuant le nombre d'accidents de la route. Néanmoins, la plupart de ces mesures préventives ne peut assurer la sécurité passive , car ils se concentrent sur la phase de collision. En fait, les matériaux comme les airbags réduisent l'impact d'un accident, mais ne l'empêchent pas. Cette reconnaissance de l'insuffisance de ces mesures passives a orienté à des perspectives industrielles nouvelles et innovantes qui cherchent à éviter les accidents et de détecter les dangers à l'avance au lieu de minimiser les dommages. En fait, selon des études pertinentes, 60 pers des accidents peuvent être évités si le conducteur avait été alerté d'une demi-seconde avant la collision. Des mesures drastiques sont déjà prises par les constructeurs automobiles afin d'offrir aux conducteurs une télématique plus large et donc d'améliorer leur gamme de sensibilisation. Si une collision est inévitable, la technologie de sécurité active peut préparer de manière proactive le véhicule pour l'impact à réduire les dommages. Par exemple, les capteurs de véhicules sont utilisés pour mesurer et évaluer l'état et de l'environnement d'un véhicule, permettant l'émission d'alertes précoces aux conducteurs. [...] / Road traffic crashes are one of the world's largest public health and injury problems. Therefore road security has always been the main concern of transportation security stakeholders. During the last decades, public authorities and automotive companies have been involved in the safety improvement of our transportation systems by reducing the consequences of imminent accidents and decreasing the number of road injuries. Nevertheless, most of these preventive measures can only provide passive safety since they focus on the post collision phase. In fact, materials of energy absorption like airbags reduce the impact of an accident but do not prevent it. This recognition of the inadequacy of these passive measures has oriented industrials to new and innovative perspectives that seek to avoid accidents and detect dangers in advance rather than minimize the damage. In fact, according to relevant studies, 60pers of accidents can be avoided if the driver had been alerted half a second before the collision. Drastic steps are already taken by automobile manufacturers to offer to drivers a larger telematics horizon and therefore enhance their range of awareness. If a collision is inevitable, active safety technology can proactively prepare the vehicle for the impact to reduce injuries. For example, vehicles' sensors are employed to measure and assess a vehicle' s condition and environment, enabling the issuance of early warnings to drivers. On the other hand, a remarkable and similar step in that direction is achieved by networking research community using vehicular networks within Intelligent Transportation Systems (ITS)

The Internet supports a diverse number of applications, which have different requirements for a number of services. Next generation networks provide high speed connectivity between hosts, which leaves the service provider to configure network devices appropriately, in order to maximize network performance. Service provider settings are based on best recommendation parameters, which give an opportunity to optimize these settings even further. This dissertation focuses on a packet discarding algorithm, known as random early detection (RED), to determine parameters which will maximize utilization of a resource. The two dominant traffic protocols used across an IP backbone are UDP and TCP. UDP traffic flows transmit packets regardless of network conditions, dropping packets without changing its transmission rates. However, TCP traffic flows concern itself with the network condition, reducing its packet transmission rate based on packet loss. Packet loss indicates that a network is congested. The sliding window concept, also known as the TCP congestion window, adjusts to the amount of acknowledgements the source node receives from the destination node. This paradigm provides a means to transmit data across the available bandwidth across a network. A well known and widely implemented simulation environment, the network simulator 2 (NS2), was used to analyze the RED mechanism. The network simulator 2 (NS2) software gained its popularity as being a complex networking simulation tool. Network protocol traffic (UDP and TCP) characteristics comply with theory, which verifies that the traffic generated by this simulator is valid. It is shown that the autocorrelation function differs between these two traffic types, verifying that the generated traffic does conform to theoretical and practical results. UDP traffic has a short-range dependency while TCP traffic has a long-range dependency. Simulation results show the effects of the RED algorithm on network traffic and equipment performance. It is shown that random packet discarding improves source transmission rate stabilization, as well as node utilization. If the packet dropping probability is set high, the TCP source transmission rates will be low, but a low packet drop probability provides high transmission rates to a few sources and low transmission rates to the majority of other sources. Therefore, an ideal packet drop probability was obtained to complement TCP source transmission rates and node utilization. Statistical distributions were fitted to sampled data from the simulations, which also show improvements to the network with random packet discarding. The results obtained contribute to congestion control across wide area networks. Even though a number of queuing management implementation exists, RED is the most widely used implementation used by service providers. / Dissertation (MEng)--University of Pretoria, 2013. / Electrical, Electronic and Computer Engineering / unrestricted

Cloud computing realizes the long-held dream of converting computing capability into a type of utility. It has the potential to fundamentally change the landscape of the IT industry and our way of life. However, as cloud computing expanding substantially in both scale and scope, ensuring its sustainable growth is a critical problem. Service providers have long been suffering from high operational costs. Especially the costs associated with the skyrocketing power consumption of large data centers. In the meantime, while efficient power/energy utilization is indispensable for the sustainable growth of cloud computing, service providers must also satisfy a user's quality of service (QoS) requirements. This problem becomes even more challenging considering the increasingly stringent power/energy and QoS constraints, as well as other factors such as the highly dynamic, heterogeneous, and distributed nature of the computing infrastructures, etc. In this dissertation, we study the problem of delay-sensitive cloud service scheduling for the sustainable development of cloud computing. We first focus our research on the development of scheduling methods for delay-sensitive cloud services on a single server with the goal of maximizing a service provider's profit. We then extend our study to scheduling cloud services in distributed environments. In particular, we develop a queue-based model and derive efficient request dispatching and processing decisions in a multi-electricity-market environment to improve the profits for service providers. We next study a problem of multi-tier service scheduling. By carefully assigning sub deadlines to the service tiers, our approach can significantly improve resource usage efficiencies with statistically guaranteed QoS. Finally, we study the power conscious resource provision problem for service requests with different QoS requirements. By properly sharing computing resources among different requests, our method statistically guarantees all QoS requirements with a minimized number of powered-on servers and thus the power consumptions. The significance of our research is that it is one part of the integrated effort from both industry and academia to ensure the sustainable growth of cloud computing as it continues to evolve and change our society profoundly.