482 research outputs found
Analyzing Methods and Opportunities in Software-Defined (SDN) Networks for Data Traffic Optimizations
Computer networks are dynamic and require constant updating and monitoring of operations to meet the growing volume of data trafficked. This generates a number of cost issues as well as performance management and tuning to deliver granular quality of service (QoS), balancing data load, and controlling the occurrence of bottlenecks. As an alternative, a new programmable network paradigm has been used under the name of Software Defined Networks (SDN). The SDN consists of decoupling the data plane and controlling the network, where a programmable controller is responsible for managing rules for routing the data to various devices. Thus, the hardware that remains in the network data stream simply addresses the routing of the packets quickly according to these rules. In this context, this article conducts a study on different methods and approaches that are being used in the literature to solve problems in the optimization of data traffic in the network through the use of SDN. In particular, this study differs from other reviews of SDN because it focuses on issues such as QoS, load balancing, and congestion control. Finally, in addition to the review of the SDN's state-of-the-art in the areas mentioned, a survey of future challenges and research opportunities in the area is also presented. load balancing and congestion control. Finally, in addition to the review of the SDN's state-of-the-art in the areas mentioned, a survey of future challenges and research opportunities in the area is also presented. load balancing and congestion control. Finally, in addition to the review of the SDN's state-of-the-art in the areas mentioned, a survey of future challenges and research opportunities in the area is also presented
Intelligent Management and Efficient Operation of Big Data
This chapter details how Big Data can be used and implemented in networking
and computing infrastructures. Specifically, it addresses three main aspects:
the timely extraction of relevant knowledge from heterogeneous, and very often
unstructured large data sources, the enhancement on the performance of
processing and networking (cloud) infrastructures that are the most important
foundational pillars of Big Data applications or services, and novel ways to
efficiently manage network infrastructures with high-level composed policies
for supporting the transmission of large amounts of data with distinct
requisites (video vs. non-video). A case study involving an intelligent
management solution to route data traffic with diverse requirements in a wide
area Internet Exchange Point is presented, discussed in the context of Big
Data, and evaluated.Comment: In book Handbook of Research on Trends and Future Directions in Big
Data and Web Intelligence, IGI Global, 201
A policy-based framework towards smooth adaptive playback for dynamic video streaming over HTTP
The growth of video streaming in the Internet in the last few years has been highly
significant and promises to continue in the future. This fact is related to the growth of
Internet users and especially with the diversification of the end-user devices that happens
nowadays.
Earlier video streaming solutions didn´t consider adequately the Quality of
Experience from the user’s perspective. This weakness has been since overcame with the
DASH video streaming. The main feature of this protocol is to provide different versions,
in terms of quality, of the same content. This way, depending on the status of the network
infrastructure between the video server and the user device, the DASH protocol
automatically selects the more adequate content version. Thus, it provides to the user the
best possible quality for the consumption of that content.
The main issue with the DASH protocol is associated to the loop, between each
client and video server, which controls the rate of the video stream. In fact, as the network
congestion increases, the client requests to the server a video stream with a lower rate.
Nevertheless, due to the network latency, the DASH protocol in a standalone way may
not be able to stabilize the video stream rate at a level that can guarantee a satisfactory
QoE to the end-users.
Network programming is a very active and popular topic in the field of network
infrastructures management. In this area, the Software Defined Networking paradigm is
an approach where a network controller, with a relatively abstracted view of the physical
network infrastructure, tries to perform a more efficient management of the data path.
The current work studies the combination of the DASH protocol and the Software
Defined Networking paradigm in order to achieve a more adequate sharing of the network
resources that could benefit both the users’ QoE and network management.O streaming de vídeo na Internet é um fenómeno que tem vindo a crescer de forma
significativa nos últimos anos e que promete continuar a crescer no futuro. Este facto está
associado ao aumento do número de utilizadores na Internet e, sobretudo, à crescente
diversificação de dispositivos que se verifica atualmente. As primeiras soluções utilizadas no streaming de vídeo não acomodavam adequadamente o ponto de vista do utilizador na avaliação da qualidade do vídeo, i.e., a Qualidade de Experiência (QoE) do utilizador. Esta debilidade foi suplantada com o protocolo de streaming de vídeo adaptativo DASH. A principal funcionalidade deste protocolo é fornecer diferente versões, em termos de qualidade, para o mesmo conteúdo. Desta forma, dependendo do estado da infraestrutura de rede entre o servidor de vídeo e o dispositivo do utilizador, o protocolo DASH seleciona automaticamente a versão do conteúdo mais adequada a essas condições. Tal permite fornecer ao utilizador a melhor
qualidade possível para o consumo deste conteúdo. O principal problema com o protocolo DASH está associado com o ciclo, entre cada cliente e o servidor de vídeo, que controla o débito de cada fluxo de vídeo. De facto, à medida que a rede fica congestionada, o cliente irá começar a requerer ao servidor um
fluxo de vídeo com um débito menor. Ainda assim, devido à latência da rede, o protocolo
DASH pode não ser capaz por si só de estabilizar o débito do fluxo de vídeo num nível
que consiga garantir uma QoE satisfatória para os utilizadores. A programação de redes é uma área muito popular e ativa na gestão de infraestruturas de redes. Nesta área, o paradigma de Software Defined Networking é uma abordagem onde um controlador da rede, com um ponto de vista relativamente abstrato
da infraestrutura física da rede, tenta desempenhar uma gestão mais eficiente do encaminhamento de rede.
Neste trabalho estuda-se a junção do protocolo DASH e do paradigma de Software Defined Networking, de forma a atingir uma partilha mais adequada dos recursos da rede. O objetivo é implementar uma solução que seja benéfica tanto para a qualidade de experiência dos utilizadores como para a gestão da rede
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