Emulating opportunistic networks with KauNet Triggers

In opportunistic networks the availability of an end-to-end path is no longer required. Instead opportunistic networks may take advantage of temporary connectivity opportunities. Opportunistic networks present a demanding environment for network emulation as the traditional emulation setup, where application/transport endpoints only send and receive packets from the network following a black box approach, is no longer applicable. Opportunistic networking protocols and applications additionally need to react to the dynamics of the underlying network beyond what is conveyed through the exchange of packets. In order to support IP-level emulation evaluations of applications and protocols that react to lower layer events, we have proposed the use of emulation triggers. Emulation triggers can emulate arbitrary cross-layer feedback and can be synchronized with other emulation effects. After introducing the design and implementation of triggers in the KauNet emulator, we describe the integration of triggers with the DTN2 reference implementation and illustrate how the functionality can be used to emulate a classical DTN data-mule scenario

Implementation of a virtualized 5G network

Dissertação de mestrado integrado em Informatics EngineeringMany organizations have developed open software components for 5G (Fifth Generation) networks and recognize the importance of new technologies based on virtualization and softwarization. With these solutions, it is possible to implement a 5G virtualized network without having access to a mobile network, which has many restrictions. Implementing a 5G testbed is essential because it allows the creation of a framework that can enable the development and research of new solutions related to 5G. This dissertation proposes a solution that uses open-source software to emulate the access network and deploys software modules that implement core network functionalities. Moreover, network capabilities, as well as interoperability, are described.Muitas organizações têm desenvolvido soluções de software aberto para componentes da rede 5G (Fifth Generation) e reconhecido a importância de novas tecnologias baseadas em virtualização e em princípios de software. É possível implementar uma rede virtualizada 5G com base nestas soluções, sem necessidade de ter acesso a uma rede móvel, o que possui muitas restrições. A criação de um ambiente de testes 5G é importante, uma vez que permite criar uma estrutura que pode possibilitar o desenvolvimento e o estudo de novas soluções relacionadas com o 5G. Nesta dissertação, é proposta uma solução emulando a rede de acesso e implementando um core recorrendo a software de código aberto. As capacidades da rede são descritas, bem como a interoperabilidade entre as diferentes soluções

Topology and congestion invariant in global internet-scale networks

PhDInfrastructures like telecommunication systems, power transmission grids and the Internet are complex networks that are vulnerable to catastrophic failure. A common mechanism behind this kind of failure is avalanche-like breakdown of the network's components. If a component fails due to overload, its load will be redistributed, causing other components to overload and fail. This failure can propagate throughout the entire network. From studies of catastrophic failures in di erent technological networks, the consensus is that the occurrence of a catastrophe is due to the interaction between the connectivity and the dynamical behaviour of the networks' elements. The research in this thesis focuses particularly on packet-oriented networks. In these networks the tra c (dynamics) and the topology (connectivity) are coupled by the routing mechanisms. The interactions between the network's topology and its tra c are complex as they depend on many parameters, e.g. Quality of Service, congestion management (queuing), link bandwidth, link delay, and types of tra c. It is not straightforward to predict whether a network will fail catastrophically or not. Furthermore, even if considering a very simpli ed version of packet networks, there are still fundamental questions about catastrophic behaviour that have not been studied, such as: will a network become unstable and fail catastrophically as its size increases; do catastrophic networks have speci c connectivity properties? One of the main di culties when studying these questions is that, in general, we do not know in advance if a network is going to fail catastrophically. In this thesis we study how to build catastrophic 5 networks. The motivation behind the research is that once we have constructed networks that will fail catastrophically then we can study its behaviour before the catastrophe occurs, for example the dynamical behaviour of the nodes before an imminent catastrophe. Our theoretical and algorithmic approach is based on the observation that for many simple networks there is a topology-tra c invariant for the onset of congestion. We have extended this approach to consider cascading congestion. We have developed two methods to construct catastrophes. The main results in this thesis are that there is a family of catastrophic networks that have a scale invariant; hence at the break point it is possible to predict the behaviour of large networks by studying a much smaller network. The results also suggest that if the tra c on a network increases exponentially, then there is a maximum size that a network can have, after that the network will always fail catastrophically. To verify if catastrophic networks built using our algorithmic approach can re ect real situations, we evaluated the performance of a small catastrophic network. By building the scenario using open source network simulation software OMNet++, we were able to simulate a router network using the Open Shortest Path First routing protocol and carrying User Datagram Protocol tra c. Our results show that this kind of networks can collapse as a cascade of failures. Furthermore, recently the failure of Google Mail routers [1] con rms this kind of catastrophic failure does occur in real situations

Simulation and Evaluation of Wired and Wireless Networks with NS2, NS3 and OMNET++

Communication systems are emerging rapidly with the revolutionary growth in terms of networking protocols, wired and wireless technologies, user applications and other IEEE standards. Numbers of industrial as well as academic organizations around the globe are bringing in light new innovations and ideas in the field of communication systems. These innovations and ideas require intense evaluation at initial phases of development with the use of real systems in place. Usually the real systems are expensive and not affordable for the evaluation. In this case, network simulators provide a complete cost-effective testbed for the simulation and evaluation of the underlined innovations and ideas. In past, numerous studies were conducted for the performance evaluation of network simulators based on CPU and memory utilization. However, performance evaluation based on other metrics such as congestion window, throughput, delay, packet delivery ratio and packet loss ratio was not conducted intensively. In this thesis, network simulators such as NS2, NS3 and OMNET++ will be evaluated and compared for wired and wireless networks based on congestion window, throughput, delay, packet delivery and packet loss ratio. In the theoretical part, information will be provided about the wired and wireless networks and mathematical interpretation of various components used for these networks. Furthermore, technical details about the network simulators will be presented including architectural design, programming languages and platform libraries. Advantages and disadvantages of these network simulators will also be highlighted. In the last part, the details about the experiments and analysis conducted for wired and wireless networks will be provided. At the end, findings will be concluded and future prospects of the study will be advised.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Modelação e simulação de equipamentos de rede para Indústria 4.0

Currently, the industrial sector has increasingly opted for digital technologies in order to automate all its processes. This development comes from notions like Industry 4.0 that redefines the way these systems are designed. Structurally, all the components of these systems are connected in a complex network known as the Industrial Internet of Things. Certain requirements arise from this concept regarding industrial communication networks. Among them, the need to ensure real-time communications, as well as support for dynamic resource management, are extremely relevant. Several research lines pursued to develop network technologies capable of meeting such requirements. One of these protocols is the Hard Real-Time Ethernet Switch (HaRTES), an Ethernet switch with support for real-time communications and dynamic resource management, requirements imposed by Industry 4.0. The process of designing and implementing industrial networks can, however, be quite time consuming and costly. These aspects impose limitations on testing large networks, whose level of complexity is higher and requires the usage of more hardware. The utilization of network simulators stems from the necessity to overcome such restrictions and provide tools to facilitate the development of new protocols and evaluation of communications networks. In the scope of this dissertation a HaRTES switch model was developed in the OMNeT++ simulation environment. In order to demonstrate a solution that can be employed in industrial real-time networks, this dissertation presents the fundamental aspects of the implemented model as well as a set of experiments that compare it with an existing laboratory prototype, with the objective of validating its implementation.Atualmente o setor industrial tem vindo cada vez mais a optar por tecnologias digitais de forma a automatizar todos os seus processos. Este desenvolvimento surge de noções como Indústria 4.0, que redefine o modo de como estes sistemas são projetados. Estruturalmente, todos os componentes destes sistemas encontram-se conectados numa rede complexa conhecida como Internet Industrial das Coisas. Certos requisitos advêm deste conceito, no que toca às redes de comunicação industriais, entre os quais se destacam a necessidade de garantir comunicações tempo-real bem como suporte a uma gestão dinâmica dos recursos, os quais são de extrema importância. Várias linhas de investigação procuraram desenvolver tecnologias de rede capazes de satisfazer tais exigências. Uma destas soluções é o "Hard Real-Time Ethernet Switch" (HaRTES), um switch Ethernet com suporte a comunicações de tempo-real e gestão dinâmica de Qualidade-de-Serviço (QoS), requisitos impostos pela Indústria 4.0. O processo de projeto e implementação de redes industriais pode, no entanto, ser bastante moroso e dispendioso. Tais aspetos impõem limitações no teste de redes de largas dimensões, cujo nível de complexidade é mais elevado e requer o uso de mais hardware. Os simuladores de redes permitem atenuar o impacto de tais limitações, disponibilizando ferramentas que facilitam o desenvolvimento de novos protocolos e a avaliação de redes de comunicações. No âmbito desta dissertação desenvolveu-se um modelo do switch HaRTES no ambiente de simulação OMNeT++. Com um objetivo de demonstrar uma solução que possa ser utilizada em redes de tempo-real industriais, esta dissertação apresenta os aspetos fundamentais do modelo implementado bem como um conjunto de experiências que o comparam com um protótipo laboratorial já existente, no âmbito da sua validação.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

Virtualization to build large scale networks

Abstract. There is not much research concerning network virtualization, even though virtualization has been a hot topic for some time and networks keep growing. Physical routers can be expensive and laborious to setup and manage, not to mention immobile. Network virtualization can be utilized in many ways, such as reducing costs, increasing agility and increasing deployment speed. Virtual routers are easy to create, copy and move. This study will research into the subjects of networks, virtualization solutions and network virtualization. Furthermore, it will show how to build a virtual network consisting of hundreds of nodes, all performing network routing. In addition, the virtual network can be connected to physical routers in the real world to provide benefits, such as performance testing or large-scale deployment. All this will be achieved using only commodity hardware

Survey and Evaluation of Advanced Mobility Management Schemes in the Host Identity Layer

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Pre-study on Multi-access Edge Computing at Communication Technology lab: simulator/emulator

Multi-access edge computing has been on the rise since the evolution of 5G. There are challenges that 5G has been fighting with, such as latency and data being transferred. In this paper, it will talk about the background of Multi-access edge computing, the state of the art of Multi-access edge computing research and then implementing a simulator to demonstrate Multi-access edge computing functionalities

Cross-layer RaCM design for vertically integrated wireless networks

Includes bibliographical references (p. 70-74).Wireless local and metropolitan area network (WLAN/WMAN) technologies, more specifically IEEE 802.11 (or wireless fidelity, WiFi) and IEEE 802.16 (or wireless interoperability for microwave access, WiMAX), are well-suited to enterprise networking since wireless offers the advantages of rapid deployment in places that are difficult to wire. However, these networking standards are relatively young with respect to their traditional mature high-speed low-latency fixed-line networking counterparts. It is more challenging for the network provider to supply the necessary quality of service (QoS) to support the variety of existing multimedia services over wireless technology. Wireless communication is also unreliable in nature, making the provisioning of agreed QoS even more challenging. Considering the advantages and disadvantages, wireless networks prove well-suited to connecting rural areas to the Internet or as a networking solution for areas that are difficult to wire. The focus of this study specifically pertains to IEEE 802.16 and the part it plays in an IEEE vertically integrated wireless Internet (WIN): IEEE 802.16 is a wireless broadband backhaul technology, capable of connecting local area networks (LANs), wireless or fixed-line, to the Internet via a high-speed fixed-line link