8 research outputs found

    Performance Analysis of SNMP in OLSRv2-routed MANETs

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    Mobile Ad Hoc NETworks (MANETs) are generally thought of as infrastructure-less and largely "un-managed", capable of accommodating highly dynamic network topologies. Yet, while the network may be un-managed, monitoring performance and setting configuration parameters post-deployment, remains important in order to ensure proper ''tuning'' and maintenance of a MANET. While SNMP is sometimes considered too ''heavy'' for MANETs -- a too chatty a protocol with too large protocol messages -- it remains the predominant management and monitoring protocol in the Internet, and many implementations exist. This \articleformat analyzes SNMP in an OLSRv2-routed MANET, with the purpose of investigating performance metrics, such as delivery ratio, delay, management overhead, collisions and performance monitoring accuracy. In order to address concerns both regarding SNMP being "heavy", as well as regarding the accuracy of performance reports obtained via SNMP polling in MANETs, where path delays can be highly variable, the utility of performance reporting proxies, i.e. the REPORT-MIB, is studied. The obtained results show that a significant benefit can be obtained by so deploying performance reporting proxies in an SNMP managed MANET. The investigations are supported by way of network simulations (NS2).Lorsquon parle de réseaux mobiles ad-hoc (MANETs), on pense généralement à des réseaux sans infrastructure et à des déploiements en réseaux largement non-gérés, pouvant s'adapter à des topologies de réseau très changeantes. Néanmoins, bien que l'infrastructure du réseau est de nature non-gérée, la surveillance des performances du réseau et le choix des paramètres de configuration une fois le réseau déployé demeurent primordiaux pour la maintenance et le réglage fin d'un réseau MANET. Alors que SNMP est parfois considéré trop "lourd" pour des MANETs, il demeure le protocole prédominant de management et monitorage d'Internet, et beaucoup implémentations du protocole existent. Ce rapport analyse SNMP dans des MANETs basés sur OLSRv2, avec l'intention de déterminer des métriques de performance, comme le taux de remise, délai, overhead et collisions dans le simulateur de réseaux NS2

    MANET Network Management and Performance Monitoring for NHDP and OLSRv2

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    Mobile Ad Hoc NETworks (MANETs) are generally thought of as infrastructureless and largely ``un-managed'' network deployments, capable of accommodating highly dynamic network topologies. Yet, while the network infrastructure may be ``un-managed'', monitoring the network performance and setting configuration parameters once deployed, remains important in order to ensure proper ``tuning'' and maintenance of a MANET. This memorandum describes a management framework for the MANET routing protocol OLSRv2, and its constituent protocol NHDP. It does so by presenting considerations for ``what to monitor and manage'' in an OLSRv2 network, and how. The approach developed is based on the Simple Network Management Protocol (SNMP), and thus this paper details the various Management Information Bases (MIBs) for router status monitoring and control -- as well as a novel approach to history-based performance monitoring. While SNMP may not be optimally designed for MANETs, it is chosen due to it being the predominant protocol for IP network management -- and thus, efforts are made in this paper to ``adapt'' the management tools within the SNMP framework for reasonable behavior also in a MANET environment

    Performance Analysis of SNMP in OLSRv2-routed MANETs

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    Mobile Ad Hoc NETworks (MANETs) are generally thought of as infrastructure-less and largely "un-managed", capable of accommodating highly dynamic network topologies. Yet, while the network may be un-managed, monitoring performance and setting configuration parameters post-deployment, remains important in order to ensure proper ''tuning'' and maintenance of a MANET. While SNMP is sometimes considered too ''heavy'' for MANETs -- a too chatty a protocol with too large protocol messages -- it remains the predominant management and monitoring protocol in the Internet, and many implementations exist. This \articleformat analyzes SNMP in an OLSRv2-routed MANET, with the purpose of investigating performance metrics, such as delivery ratio, delay, management overhead, collisions and performance monitoring accuracy. In order to address concerns both regarding SNMP being "heavy", as well as regarding the accuracy of performance reports obtained via SNMP polling in MANETs, where path delays can be highly variable, the utility of performance reporting proxies, i.e. the REPORT-MIB, is studied. The obtained results show that a significant benefit can be obtained by so deploying performance reporting proxies in an SNMP managed MANET. The investigations are supported by way of network simulations (NS2).Lorsquon parle de réseaux mobiles ad-hoc (MANETs), on pense généralement à des réseaux sans infrastructure et à des déploiements en réseaux largement non-gérés, pouvant s'adapter à des topologies de réseau très changeantes. Néanmoins, bien que l'infrastructure du réseau est de nature non-gérée, la surveillance des performances du réseau et le choix des paramètres de configuration une fois le réseau déployé demeurent primordiaux pour la maintenance et le réglage fin d'un réseau MANET. Alors que SNMP est parfois considéré trop "lourd" pour des MANETs, il demeure le protocole prédominant de management et monitorage d'Internet, et beaucoup implémentations du protocole existent. Ce rapport analyse SNMP dans des MANETs basés sur OLSRv2, avec l'intention de déterminer des métriques de performance, comme le taux de remise, délai, overhead et collisions dans le simulateur de réseaux NS2

    Towards a network management solution for vehicular delay-tolerant networks

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    Vehicular networks appeared as a new communication solution where vehicles act as a communication infrastructure, providing data communications through vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communications. Vehicular Delay-Tolerant Networks (VDTNs) are a new disruptive network architecture assuming delay tolerant networking paradigm where there are no end-to-end connectivity. In this case the incial node transmits the data to a closed node, the data will be carried by vehicles, hop to hop until the destination. This dissertation focuses on a proposal of a network management solution, based standard protocol Simple Network Management Protocol (SNMP) to VDTN networks. The developed solution allows control a VDTN netowork through a Network Management System (NMS) with the objective to detect and, if it’s possible, anticipate, possible errors on network. The research methodology used was the prototyping. So, it was built a network management module to the laboratorial prototype, called VDTN@Lab. The system built include a MIB (Management Information Base) placed in all vehicular network nodes. The solution was built, demonstrated, validated and evaluated their performance, being ready for use.As redes veiculares foram desenhadas para permitir que os veículos possam transportar dados criando assim um novo tipo de redes, caracterizando-se por dois tipos de comunicação: comunicações veículo-para-veículo (V2V) ou comunicações veículo-parainfra-estrutura (V2I). Redes veiculares intermitentes (do Inglês Vehicular Delay-Tolerant Networks - VDTNs) surgiram como uma nova arquitectura de rede de dados onde os veículos são utilizados como infra-estruturas de comunicação. As VDTNs caracterizam-se por serem redes veiculares baseadas no paradigma de comunicações intermitentes. Nas redes VDTN não existe uma ligação permanente extremo a extremo entre o emissor e o receptor. Neste caso, o nó inicial transmite os dados para um nó que esteja junto dele e assim sucessivamente, os dados vão sendo transportados pelos veículos, salto a salto até ao destinatário final. Esta dissertação centra-se na proposta de uma solução de gestão de rede, baseada no protocolo estandardizado Simple Network Management Protocol (SNMP) para redes VDTN. A solução construída permite controlar uma rede VDTN através de um sistema de gestão de rede (do Inglês Network Management System - NMS) com o objectivo de detectar e, se possível antecipar, possíveis erros na rede. A metodologia de investigação utilizada foi a prototipagem. Assim, foi construído um módulo de gestão de redes para o protótipo laboratorial, chamado VDTN@Lab. O sistema construído inclui uma MIB (Management Information Base) que é colocada em todos os nós de uma rede veicular, tanto fixos como móveis. A solução foi construída, demonstrada, validade e avaliado o seu desempenho, estando assim pronta para ser utilizada

    Initial design and concept of operations for a clandestine data relay UUV to circumvent jungle canopy effects on satellite communications

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    Communications within jungle environments has always been a difficult proposition. This is especially true of collection assets beneath triple canopy jungle that need to communicate with overhead national assets. The traditional methods of countering the negative effects of the canopy on EM signals have been to increase the power to offset the losses, or to utilize new, more canopy transparent portions of the EM spectrum. However, there are complications with both of these methods. Simply increasing transmitted power increases the drain on the system's power supply, thus lowering effective on-station time. Shifting to a different portion of the EM spectrum can negatively affect the transmission rate of the system and requires specialized equipment such as antennas and modulators. This work addresses the issue by designing a semi-autonomous UUV, which will clandestinely relay data from the embedded jungle systems to overhead national assets. Rather than trying to punch through the canopy directly, the proposed UUV will take advantage of the fact that most jungle water ways have, at the very least, a thinner canopy overhead if not a clear view of the sky for less lossy satellite communications. This shifts the primary communications from an Earth-Sky problem to a lateral wave model where the communications travels parallel to the canopy. While the jungle is still not an ideal medium for communications, other methods can be used to address these losses. The proposed UUV will be designed to be cheap and constructed from existing systems. It will also be small, and lightweight, enough to be delivered and deployed in theater via aircraft, boats, and operators on the ground. Additionally it will be capable of long on station times due to the ability recharge on station.http://archive.org/details/initialdesignndc109455537Approved for public release; distribution is unlimited

    An analysis of voice over internet protocol in wireless mesh networks

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    Magister Scientiae - MScThis thesis presents an analysis of the impact of node mobility on the quality of service for voice over Internet Protocol in wireless mesh networks. Voice traffic was simulated on such a mesh network to analyze the following performance metrics: delay, jitter, packet loss and throughput. Wireless mesh networks present interesting characteristics such as multi-hop routing, node mobility, and variable coverage that can impact on quality of service. A reasonable deployment scenario for a small organizational network, for either urban or rural deployment, is considered with three wireless mesh network scenarios, each with 26 mesh nodes. In the first scenario, all mesh nodes are stationary. In the second scenario, 10 nodes are mobile and 16 nodes are stationary. Finally, in the third scenario, all mesh nodes are mobile. The mesh nodes are simulated to move at a walking speed of 1.3m per second. The results show that node mobility can increase packet loss, delay, and jitter. However, the results also show that wireless mesh networks can provide acceptable quality of service, providing that there is little or no background traffic generated by other applications. In particular, the results demonstrate that jitter across all scenarios remains within humanacceptable tolerances. It is therefore recommended that voice over Internet Protocol implementations on wireless mesh networks with background traffic be supported by quality of service standards; otherwise they can lead to service delivery failures. On the other hand, voice-only esh networks, even with mobile nodes, offer an attractive alternative voice over Internet Protocol platform.South Afric

    Routing and Mobility on IPv6 over LoWPAN

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    The IoT means a world-wide network of interconnected objects based on standard communication protocols. An object in this context is a quotidian physical device augmented with sensing/actuating, processing, storing and communication capabilities. These objects must be able to interact with the surrounding environment where they are placed and to cooperate with neighbouring objects in order to accomplish a common objective. The IoT objects have also the capabilities of converting the sensed data into automated instructions and communicating them to other objects through the communication networks, avoiding the human intervention in several tasks. Most of IoT deployments are based on small devices with restricted computational resources and energy constraints. For this reason, initially the scientific community did not consider the use of IP protocol suite in this scenarios because there was the perception that it was too heavy to the available resources on such devices. Meanwhile, the scientific community and the industry started to rethink about the use of IP protocol suite in all IoT devices and now it is considered as the solution to provide connectivity between the IoT devices, independently of the Layer 2 protocol in use, and to connect them to the Internet. Despite the use of IP suite protocol in all devices and the amount of solutions proposed, many open issues remain unsolved in order to reach a seamless integration between the IoT and the Internet and to provide the conditions to IoT service widespread. This thesis addressed the challenges associated with the interconnectivity between the Internet and the IoT devices and with the security aspects of the IoT. In the interconnectivity between the IoT devices and the Internet the problem is how to provide valuable information to the Internet connected devices, independently of the supported IP protocol version, without being necessary accessed directly to the IoT nodes. In order to solve this problem, solutions based on Representational state transfer (REST) web services and IPv4 to IPv6 dual stack transition mechanism were proposed and evaluated. The REST web service and the transition mechanism runs only at the border router without penalizing the IoT constrained devices. The mitigation of the effects of internal and external security attacks minimizing the overhead imposed on the IoT devices is the security challenge addressed in this thesis. Three different solutions were proposed. The first is a mechanism to prevent remotely initiated transport level Denial of Service attacks that avoids the use of inefficient and hard to manage traditional firewalls. It is based on filtering at the border router the traffic received from the Internet and destined to the IoT network according to the conditions announced by each IoT device. The second is a network access security framework that can be used to control the nodes that have access to the network, based on administrative approval, and to enforce security compliance to the authorized nodes. The third is a network admission control framework that prevents IoT unauthorized nodes to communicate with IoT authorized nodes or with the Internet, which drastically reduces the number of possible security attacks. The network admission control was also exploited as a management mechanism as it can be used to manage the network size in terms of number of nodes, making the network more manageable, increasing its reliability and extending its lifetime.A IoT (Internet of Things) tem suscitado o interesse tanto da comunidade académica como da indústria, uma vez que os campos de aplicação são inúmeros assim como os potenciais ganhos que podem ser obtidos através do uso deste tipo de tecnologia. A IoT significa uma rede global de objetos ligados entre si através de uma rede de comunicações baseada em protocolos standard. Neste contexto, um objeto é um objeto físico do dia a dia ao qual foi adicionada a capacidade de medir e de atuar sobre variáveis físicas, de processar e armazenar dados e de comunicar. Estes objetos têm a capacidade de interagir com o meio ambiente envolvente e de cooperar com outros objetos vizinhos de forma a atingirem um objetivo comum. Estes objetos também têm a capacidade de converter os dados lidos em instruções e de as comunicar a outros objetos através da rede de comunicações, evitando desta forma a intervenção humana em diversas tarefas. A maior parte das concretizações de sistemas IoT são baseados em pequenos dispositivos autónomos com restrições ao nível dos recursos computacionais e de retenção de energia. Por esta razão, inicialmente a comunidade científica não considerou adequado o uso da pilha protocolar IP neste tipo de dispositivos, uma vez que havia a perceção de que era muito pesada para os recursos computacionais disponíveis. Entretanto, a comunidade científica e a indústria retomaram a discussão acerca dos benefícios do uso da pilha protocolar em todos os dispositivos da IoT e atualmente é considerada a solução para estabelecer a conetividade entre os dispositivos IoT independentemente do protocolo da camada dois em uso e para os ligar à Internet. Apesar do uso da pilha protocolar IP em todos os dispositivos e da quantidade de soluções propostas, são vários os problemas por resolver no que concerne à integração contínua e sem interrupções da IoT na Internet e de criar as condições para a adoção generalizada deste tipo de tecnologias. Esta tese versa sobre os desafios associados à integração da IoT na Internet e dos aspetos de segurança da IoT. Relativamente à integração da IoT na Internet o problema é como fornecer informação válida aos dispositivos ligados à Internet, independentemente da versão do protocolo IP em uso, evitando o acesso direto aos dispositivos IoT. Para a resolução deste problema foram propostas e avaliadas soluções baseadas em web services REST e em mecanismos de transição IPv4 para IPv6 do tipo pilha dupla (dual stack). O web service e o mecanismo de transição são suportados apenas no router de fronteira, sem penalizar os dispositivos IoT. No que concerne à segurança, o problema é mitigar os efeitos dos ataques de segurança internos e externos iniciados local e remotamente. Foram propostas três soluções diferentes, a primeira é um mecanismo que minimiza os efeitos dos ataques de negação de serviço com origem na Internet e que evita o uso de mecanismos de firewalls ineficientes e de gestão complexa. Este mecanismo filtra no router de fronteira o tráfego com origem na Internet é destinado à IoT de acordo com as condições anunciadas por cada um dos dispositivos IoT da rede. A segunda solução, é uma framework de network admission control que controla quais os dispositivos que podem aceder à rede com base na autorização administrativa e que aplica políticas de conformidade relativas à segurança aos dispositivos autorizados. A terceira é um mecanismo de network admission control para redes 6LoWPAN que evita que dispositivos não autorizados comuniquem com outros dispositivos legítimos e com a Internet o que reduz drasticamente o número de ataques à segurança. Este mecanismo também foi explorado como um mecanismo de gestão uma vez que pode ser utilizado a dimensão da rede quanto ao número de dispositivos, tornando-a mais fácil de gerir e aumentando a sua fiabilidade e o seu tempo de vida

    Performance Analysis of SNMP in OLSRv2-routed MANETs

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    Abstract-Mobile Ad Hoc NETworks (MANETs) are generally thought of as infrastructure-less and largely "un-managed". Yet, while the network may be un-managed, monitoring performance and setting configuration parameters post-deployment, remains important in order to ensure proper "tuning" and maintenance of a MANET. While SNMP is sometimes considered too "heavy" for MANETs, it remains the predominant management and monitoring protocol in the Internet. This paper evaluates SNMP in an OLSRv2-routed MANET, with the purpose of investigating performance metrics. In order to address concerns both regarding SNMP being "heavy", as well as regarding the accuracy of performance reports obtained via SNMP polling in MANETs, the utility of performance reporting proxies is studied. The obtained results show that a significant benefit can be obtained by deploying performance reporting proxies in an SNMP managed MANET
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