345 research outputs found
RODMRP - resilient on demand multicast routing protocol
ODMRP (On-Demand Multicast Routing Protocol) [6] [8] [2] is a popular multicast protocol for wireless ad hoc networks. The strengths of ODMRP are simplicity, high packet delivery ratio, and non-dependency on a specific unicast protocol. ODMRP floods a route request over the entire network to select a set of forwarding nodes for packet delivery. However, a single forwarding path is vulnerable to node failures, which are common due to the dynamic nature of mobile ad hoc networks. Furthermore, a set of misbehaving or malicious nodes can create network partitions and mount Denial-of-Service (DoS) attacks. This thesis proposes a ODMRP-based wireless multicast protocol named RODMRP that offers more reliable forwarding paths in face of node and network failures. A subset of the nodes that are not on forwarding paths rebroadcast received packets to nodes in their neighborhoods to overcome perceived node failures. This rebroadcasting creates redundant forwarding paths to circumvent failed areas in the network. Each node makes this forwarding decision probabilistically. Our simulation results indicate that RODMRP improves packet delivery ratio with minimal overheads, while retaining the original strengths of ODMRP
Application-Independent Based Multicast Routing Protocols in Mobile Ad hoc Network (MANET)
Multicasting is an efficient communication service for supporting multipoint applications. The main goal of most ad hoc multicast protocols is to build and maintain a multicast tree or mesh in the face of a mobile environment, with fast reactions to network changes so that the packet loss is minimized. The topology of a wireless mobile network can be very dynamic, and hence the maintenance of a connected multicast routing tree may cause large overhead. To avoid this, a different approach based on meshes has been proposed. Meshes are more suitable for dynamic environments because they support more connectivity than trees; thus they support multicast trees. In multicast routing protocols many type of risk are involve like rushing, black hole, jellyfish attacks. Many features improve the performance of multicast routing protocol robustness, efficiency, control overhead .in this article mainly focus on application independent based multicast routing protocols, features, and comparison of multicast routing protocols. Keywords: Ad hoc Network, CAMP, ODMRP, AMRIS, MAODV etc
A P2P Platform for real-time multicast video streaming leveraging on scalable multiple descriptions to cope with bandwidth fluctuations
In the immediate future video distribution applications will increase their diffusion thanks tothe ever-increasing user capabilities and improvements in the Internet access speed and performance.The target of this paper is to propose a content delivery system for real-time streaming services based ona peer-to-peer approach that exploits multicast overlay organization of the peers to address thechallenges due to bandwidth heterogeneity. To improve reliability and flexibility, video is coded using ascalable multiple description approach that allows delivery of sub-streams over multiple trees andallows rate adaptation along the trees as the available bandwidth changes. Moreover, we have deployeda new algorithm for tree-based topology management of the overlay network. In fact, tree based overlaynetworks better perform in terms of end-to-end delay and ordered delivery of video flow packets withrespect to mesh based ones. We also show with a case study that the proposed system works better thansimilar systems using only either multicast or multiple trees
Scalability and Resilience Analysis of Software-Defined Networking
Software-defined Networking (SDN) ist eine moderne Architektur fĂŒr Kommunikationsnetze, welche entwickelt wurde, um die EinfĂŒhrung von neuen Diensten und Funktionen in Netzwerke zu erleichtern. Durch eine Trennung der Weiterleitungs- und Kontrollfunktionen sind nur wenige Kontrollelemente mit Software-Updates zu versehen, um VerĂ€nderungen am Netz vornehmen zu können. Allerdings wirft die Netzstrukturierung von SDN neue Fragen bezĂŒglich Skalierbarkeit und Ausfallsicherheit auf, welche in dezentralen Netzstrukturen nicht auftreten. In dieser Arbeit befassen wir uns mit Fragestellungen zu Skalierbarkeit und Ausfallsicherheit in Bezug auf Unicast- und Multicast-Verkehr in SDN-basierten Netzen. Wir fĂŒhren eine Komprimierungstechnik fĂŒr Routingtabellen ein, welche die Skalierungsproblematik aktueller SDN WeiterleitungsgerĂ€te verbessern soll und ermitteln ihre Effizienz in einer Leistungsbewertung. AuĂerdem diskutieren wir unterschiedliche Methoden, um die Ausfallsicherheit in SDN zu verbessern. Wir analysieren sie auf öffentlich zugĂ€nglichen Netzwerken und benennen Vor- und Nachteile der AnsĂ€tze. AbschlieĂend schlagen wir eine skalierbare und ausfallsichere Architektur fĂŒr Multicast-basiertes SDN vor. Wir untersuchen ihre Effizienz in einer Leistungsbewertung und zeigen ihre Umsetzbarkeit mithilfe eines Prototypen.Software-Defined Networking (SDN) is a novel architecture for communication networks that has been developed to ease the introduction of new network services and functions. It leverages the separation of the data plane and the control plane to allow network services to be deployed solely in software. Although SDN provides great flexibility, the applicability of SDN in communication networks raises several questions with regard to scalability and resilience against network failures. These concerns are not prevalent in current decentralized network architectures. In this thesis, we address scalability and resilience issues with regard to unicast and multicast traffic for SDN-based networks. We propose a new compression method for inter-domain routing tables to address hardware limitations of current SDN switches and analyze its effectiveness. We propose various resilience methods for SDN and identify their key performance indicators in the context of carrier-grade and datacenter networks. We discuss the advantages and disadvantages of these proposals and their appropriate use cases. Finally, we propose a scalable and resilient software-defined multicast architecture. We study the effectiveness of our approach and show its feasibility using a prototype implementation
04411 Abtracts Collection -- Service Management and Self-Organization in IP-based Networks
From 03.10.04 to 06.10.04,
the Dagstuhl Seminar
04411 ``Service Management and Self-Organization in IP-based Networks\u27\u27 was held
in the International Conference and Research Center (IBFI), Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
Optimizing Network Coding Algorithms for Multiple Applications.
Deviating from the archaic communication approach of treating information as a fluid moving through pipes, the concepts of Network Coding (NC) suggest that optimal throughput of a multicast network can be achieved by processing information at individual network nodes. However, existing challenges to harness the advantages of NC concepts for practical applications have prevented the development of NC into an effective solution to increase the performance of practical communication networks. In response, the research work presented in this thesis proposes cross-layer NC solutions to increase the network throughput of data multicast as well as video quality of video multicast applications. First, three algorithms are presented to improve the throughput of NC enabled networks by minimizing the NC coefficient vector overhead, optimizing the NC redundancy allocation and improving the robustness of NC against bursty packet losses. Considering the fact that majority of network traffic occupies video, rest of the proposed NC algorithms are content-aware and are optimized for both data and video multicast applications. A set of content and network-aware optimization algorithms, which allocate redundancies for NC considering content properties as well as the network status, are proposed to efficiently multicast data and video across content delivery networks. Furthermore content and channel-aware joint channel and network coding algorithms are proposed to efficiently multicast data and video across wireless networks. Finally, the possibilities of performing joint source and network coding are explored to increase the robustness of high volume video multicast applications. Extensive simulation studies indicate significant improvements with the proposed algorithms to increase the network throughput and video quality over related state-of-the-art solutions. Hence, it is envisaged that the proposed algorithms will contribute to the advancement of data and video multicast protocols in the future communication networks
Reconfigurable remote nodes for hybrid passive optical networks
Mestrado em Engenharia Electrónica e TelecomunicaçÔesO presente documento tem por objectivo demonstrar, analisar e optimizar nós remotos passivos para redes ópticas passivas baseadas numa topologia de anel de dupla fibra com multiplexagem no comprimento de onda onde estão
penduradas ĂĄrvores mono fibra baseadas na multiplexagem no tempo. A rede âScalable Advanced Ring-based passive Dense Access Network Architectureâ (SARDANA) baseada nesta topologia Ă© apresentada e demonstrada.
Na rede SARDANA a interligação entre o anel e as ĂĄrvores Ă© realizada pelo intermĂ©dio de um nĂł especial denominado de nĂł remoto. Esse nĂł remoto Ă© um elemento fundamental para o funcionamento, resiliĂȘncia e escalabilidade da
rede. Neste documento são apresentadas e comparadas diferentes topologias para a implementação desse nó remoto. à também apresentada a reconfigurabilidade remota desses mesmos nós remotos através de módulos de conversão energética e controlo, implementada nos nós remotos.
Um factor importante para a optimização dos nós remotos é a amplificação remota realizada por intermédio de fibras dopadas de érbio pelo que o seu estudo é também apresentado.
Finalmente Ă© demonstrado um protĂłtipo de um nĂł remotamente reconfigurado e eficiente.
ABSTRACT: The objective of this document is to demonstrate, analyze and optimize remote nodes for passive optical networks based on double fiber ring multiplexed in wavelength connected to single fiber trees multiplexed in time. The network
âScalable Advanced Ring-based passive Dense Access Network Architectureâ (SARDANA) based on this topology is presented and demonstrated.
In the SARDANA network the interconnection between the ring and the trees is done by means of a special node, the remote node. This node is a fundamental element to the operation, resiliency and scalability of the network. This document presents and compares different topologies to the implementation of the remote node. Remotely reconfigurability of the remote nodes is also
demonstrated by means of optical conversion and control modules.
An important factor to the optimization of the remote nodes is the remote amplification done by means of erbium doped fibers being presented the
analysis of the amplifier.
Finally is demonstrated a prototype of a node remotely reconfigured and efficient
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