• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 68
  • 24
  • 23
  • 14
  • 10
  • 7
  • 6
  • 3
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 170
  • 76
  • 67
  • 61
  • 53
  • 41
  • 36
  • 25
  • 21
  • 20
  • 19
  • 19
  • 17
  • 16
  • 15
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Monitoring of a Modelled Real-Time System : with Data Diode Enabled Unidirectional Network / Övervakning av ett modellerat realtidssystem : Enkelriktat nätverk möjliggjort av dioder

Sterneling, Hanna January 2020 (has links)
Monitoring and logging is fundamental in systems. Today, these techniques are widely used to detect functionality issues as well as malicious event. This thesis compares and evaluates two techniques commonly used for this purpose: the Simple Network Management Protocol (SNMP) and the Syslog protocol. The protocols are evaluated with regard to their vulnerability to traffic pattern analysis, impact on network load and performance of the system, and the attack surface of the technique. Each protocol’s applicability is investigated on a modelled system, containing a data diode, using experiments and analysis of their individual features. We observe only small differences in traffic load and performance of the two techniques. The findings suggest that each of the two techniques can successfully be applied on the modelled system, and the decision on which technique should be used at each instance can therefore be left to the customer of each specific system implementation instance.
142

Analysis of network management protocols in optical networks

Lim, Kok Seng 03 1900 (has links)
Approved for public release, distribution is unlimited / In this thesis, the scalability issues of Simple Network Management Protocol (SNMP) in optical network management are explored. It is important to understand the effect of varying the number of nodes, the request inter-arrival times and the polling interval on the performance of SNMP and number of nodes that can be effectively managed. The current study explored the effect of varying these parameters in a controlled test environment using the OPNET simulation package. In addition, traffic analysis was performed on measured SNMP traffic and statistics were developed from the traffic analysis. With this understanding of SNMP traffic, an SNMPv1 model was defined and integrated into an OPNET network model to study the performance of SNMP. The simulation results obtained were useful in providing needed insight into the allowable number of nodes an optical network management system can effectively manage. / Civilian, Singapore Ministry of Defense
143

Správa sítí na bázi protokolu IP / Management of data networks based on IP protocol

Patala, Petr January 2012 (has links)
The objective of this master’s thesis is monitoring and management of computer networks via SNMP protocol and its practical application. The main part describes working with SNMPc program in an experimental network through implementation of its parts into the network and configuration of SNMP agents on routers, switch and end station. This thesis includes the results of traffic testing, disconnected links, effects of traffic load on QoS parameters, making longterm statistics, baselines and alarms. The thesis also includes parametres obtained with SNMP protocol from network nodes and end station.
144

Réseaux Ad Hoc : Performance, Dimensionnement, Gestion Automatisée et Intégration dans l'Internet

Herberg, Ulrich 20 May 2011 (has links) (PDF)
Le présent rapport fournit plusieurs extensions des protocoles de réseau ad hoc et leurs évaluations, qui permettent d'augmenter la performance, de dimensionner la taille des réseaux et d'intégrer les réseaux ad hoc dans l'Internet : Premièrement, ce rapport présente plusieurs outils de logiciel qui permettent d'étudier des protocoles de routage sans modifications, implémentés en Java, dans le simulator de réseaux NS2. Deuxièmement, ce rapport fournit une discussion architecturale des réseaux ad hoc, qui explique les problèmes de la configuration automatique des adresses IP (nommé autoconfiguration) des routeurs ad hoc. Ensuite, le rapport présente un modèle architectural pour des réseaux ad hoc qui est compatible avec l'Internet. Un protocole d'autoconfiguration, basé sur le modèle architectural proposé, est spécifié, et ses propriétés sont formellement vérifiées au moyen de Model Checking. Troisièmement, plusieurs extensions du protocole de routage des réseaux ad hoc OLSRv2 sont présentées : La performance du protocole est augmentée d'ordre de grandeur en utilisant un algorithme dynamique pour calculer les plus courts chemins. Une autre optimisation proposée est un framework basé sur SNMP pour gérer et contrôler des objets liés à la performance sur des routeurs tournant OLSRv2. Une extension d'OLSRv2 est présentée dans laquelle des paquets sont retransmis ultérieurement lorsque les destinations sont indisponibles temporairement, au lieu de les rejeter. Cette extension mène à un taux de remis considérablement plus élevé que OLSRv2 par défaut dans certains scenarios. Ce rapport présente alors une analyse des menaces de sécurité pour OLSRv2, suivie par la spécification d'un mécanisme de contrôle d'accès pour OLSRv2, qui empêche nombre de ces attaques. Quatrièmement, ce rapport explore le dimensionnement des réseaux de capteurs sans fil, et évalue un protocole de routage des réseaux de capteurs, nommé RPL, spécifié par l'IETF en 2011. En outre, étant donné que RPL ne contient pas de mécanisme de broadcast efficace, plusieurs mécanismes de broadcast optimisés dans RPL sont présentés et comparés.
145

Granskning och optimering av data- och IP-telefoninätverk

Eriksson, Jhonny, Karlsson, Joel January 2010 (has links)
<p>The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption.</p> / <p>Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.</p>
146

Das MTA-Protokoll: Ein transaktionsorientiertes Managementprotokoll auf Basis von SNMP

Mandl, Peter 30 January 2013 (has links) (PDF)
Die sich in den letzten Jahren abzeichnende Verteilung von Anwendungssystemen auf viele Rechner in Netzwerken, die sich in der Praxis unter dem Begriff Client/Server-Computing etabliert hat, brachte zwangsläufig eine Lücke im Management dieser Systeme mit sich. Es wurde schnell deutlich, daß die Verteilung der Systeme wesentlich kompliziertere Techniken benötigt, um sie zu administrieren, als man dies von zentralistischen Systemen her kannte. Anstrengungen von Standardisierungsgremien und Herstellervereinigungen führten zwar zu einer gewissen Administrierbarkeit, diese beschränkt sich aber derzeit noch weitgehend auf die beteiligten Knoten und auf die Netzkomponenten. Anwendungen, für die ja letztendlich die Rechner eingesetzt werden, sind bisher nur rudimentär in die heute vorliegenden und in der Praxis eingesetzten Managementstandards integriert. Die Anzahl der zu managenden Objekte innerhalb der Anwendungen wird aber immer größer und die Komplexität der Beziehungen unter den Objekten steigt immer mehr an. Diese Komplexität erfordert fehlertolerante Mechanismen in den Managementsystemen, über die Anwendungen administriert werden. Dieser Beitrag befaßt sich mit Mechanismen zum transaktionsgesicherten Management, wobei das Anwendungsmanagement im Vordergrund steht. Transaktionskonzepte, die vorwiegend im Datenbankbereich entwickelt wurden, werden auf die Verwendbarkeit im Management verteilter Anwendungen hin untersucht. Es wird ein neues Protokoll (Management-Transaktions-Protokoll, kurz MTAProtokoll) als Erweiterung zu SNMP vorgestellt, das die Abwicklung von verteilten Transaktionen auf Managementobjekte ermöglicht.
147

Granskning och optimering av data- och IP-telefoninätverk

Eriksson, Jhonny, Karlsson, Joel January 2010 (has links)
The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption. / Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.
148

Uma solução para composição de serviços de gerenciamento de redes utilizando padrões web services / A Solution for network management services composition using web services standards

Vianna, Ricardo Lemos January 2007 (has links)
Nos últimos anos, a tecnologia de Web Services vem sendo pesquisada nas mais diversas áreas da computação, incluindo a de gerenciamento de redes de computadores. A composição de serviços, uma nova funcionalidade surgida recentemente, parece ter a potencialidade de resolver diversos problemas de diversas áreas da computação, incluindo a área de gerenciamento de redes e seu respectivo protocolo padrão de facto, o SNMP. Através da composição de serviços, é possível construir serviços mais sofisticados, usando-se serviços mais simples como componentes. Este trabalho tem por objetivo investigar a composição de Web Services aplicada ao gerenciamento de redes de computadores. Para tanto, modelos e padrões para composição foram estudados e uma arquitetura de composição, usando o padrão WS-BPEL, aplicada ao gerenciamento foi proposta. Tal arquitetura permite iniciar uma cadeia de ações de gerenciamento em gerentes de nível mais baixo baseados em Web Services através de uma única requisição Web Service. Para definir novas composições, uma ferramenta Web foi desenvolvida, a qual gera automaticamente o código WS-BPEL. Além disso, foram realizadas avaliações de desempenho para verificar o impacto na rede das composições. Os resultados obtidos mostraram que composições podem reduzir o tráfego gerado na rede junto à estação de gerenciamento, pois permitem concentrar diversas informações em uma única requisição Web Services. O tempo de resposta também pôde ser reduzido em algumas situações devido às requisições nativamente paralelas do WS-BPEL. / In the recent years, the Web Services technology has been researched in many areas of computer science, including computers network management. Service composition, a new feature recently raised, seems to have the potentiality to solve several problems in computer science, including the network management field and its Simple Network Management Protocol (SNMP). Through service composition, it is possible to build up more sophisticated services using simpler services as components. Therefore, this work aims at investigating Web Services composition applied to network management. Towards this goal, models and standards for composition were reviewed and a WS-BPEL-based composition architecture devoted to management was proposed. Such architecture allows starting a chain of management actions on lowerlevel Web Services-based managers through only one Web Services request. In order to define new compositions, a Web-based tool was developed to automatically generate the WS-BPEL required code. In addition, performance evaluations were carried out in order to verify the compositions’ impact on the managed network. The results showed that compositions can reduce the management traffic in the surroundings of the management station by aggregating several information in only one Web Services request. Response time could also be decreased in some situations due to the native parallel requests of WS-BPEL.
149

Segurança em gerenciamento de redes baseado em web services / Security in web services-based network management

Rohr, Estêvão Miguel Zanette January 2009 (has links)
A área de gerência de redes encontra uma série de desafios desde seu príncipio. O protocolo que surgiu como padrão para gerência de redes, o SNMP, possui uma série de limitações, por exemplo, no tocante à segurança, configuração de equipamentos e composição de serviços. Por essa razão, tecnologias alternativas para o gerenciamento de redes têm sido pesquisadas. A tecnologia de Web Services surgiu como forte alternativa, por características como o uso de padrões amplamente suportados (HTTP e XML) e modelo de desenvolvimento orientado a serviços. Pesquisas iniciais demonstraram que os Web Services são uma alternativa viável em termos de desempenho. Assim, o uso de Web Services em áreas específicas de gerência de redes, como notificações e gerência por delegação, tem sido pesquisado. Porém, há carência de estudos sobre o uso de segurança no gerenciamento de redes via Web Services. Os Web Services trazem facilidade para uso de segurança, que é vital para a gerência de redes, e este é o foco deste trabalho. É proposta uma arquitetura de integração de segurança à comunicação de mensagens de gerenciamento de redes via Web Services. Para isso, foram utilizados o padrão WS-Security, para segurança em Web Services, e o padrão WS-Management, para gerenciamento de redes via Web Services. Também foi integrado controle de acesso à arquitetura, com uso do padrão XACML. Uma avaliação de desempenho foi realizada para verificar o impacto do uso de segurança, e comparações com SNMPv3 foram realizadas na solução de controle de acesso via XACML. Os testes mostram que, como é tradicional, a segurança tem impacto considerável no tempo de processamento e tráfego na rede. Porém, a arquitetura e implementação realizadas comprovam que, também na área de segurança, a tecnologia de Web Services tem aplicação eficaz para o gerenciamento de redes. / The network management field has several challenges since its beginning. The standard protocol for network management, SNMP, has many drawbacks, related to security, device configuration, and service composition. For these reason, alternative technologies for network management have been investigated. Web Services technology emerged as a strong solution, due to advantages such as employing widely supported standards (HTTP and XML) and service-oriented development model. The first performed investigations in the area showed that Web Services are a valid alternative to SNMP in terms of performance. Thus, Web Services usage in specific areas of network management, such as notifications and management by delegation, have been researched. However, there are currently no studies on security aspects of Web Services-based network management. Web Services enable easy integration of security, which is mandatory for network management, and this is the main goal of this work. An architecture is proposed for security integration in a network management message communication using Web Services. The standards used in this architecture were WSSecurity, which enables security in Web Services, and WS-Management, which targets Web Services-based network management. Access control integration was also developed, using XACML standard. A performance evaluation was carried out in order to verify security usage impact, and comparisons with SNMPv3 were performed in XACML access control solution. Tests showed that, as expected, security has a considerable impact in processing time and network traffic. However, the architecture and implementation show that, also in the security area, the Web Services technology has effective aplication in network management.
150

Segurança em gerenciamento de redes baseado em web services / Security in web services-based network management

Rohr, Estêvão Miguel Zanette January 2009 (has links)
A área de gerência de redes encontra uma série de desafios desde seu príncipio. O protocolo que surgiu como padrão para gerência de redes, o SNMP, possui uma série de limitações, por exemplo, no tocante à segurança, configuração de equipamentos e composição de serviços. Por essa razão, tecnologias alternativas para o gerenciamento de redes têm sido pesquisadas. A tecnologia de Web Services surgiu como forte alternativa, por características como o uso de padrões amplamente suportados (HTTP e XML) e modelo de desenvolvimento orientado a serviços. Pesquisas iniciais demonstraram que os Web Services são uma alternativa viável em termos de desempenho. Assim, o uso de Web Services em áreas específicas de gerência de redes, como notificações e gerência por delegação, tem sido pesquisado. Porém, há carência de estudos sobre o uso de segurança no gerenciamento de redes via Web Services. Os Web Services trazem facilidade para uso de segurança, que é vital para a gerência de redes, e este é o foco deste trabalho. É proposta uma arquitetura de integração de segurança à comunicação de mensagens de gerenciamento de redes via Web Services. Para isso, foram utilizados o padrão WS-Security, para segurança em Web Services, e o padrão WS-Management, para gerenciamento de redes via Web Services. Também foi integrado controle de acesso à arquitetura, com uso do padrão XACML. Uma avaliação de desempenho foi realizada para verificar o impacto do uso de segurança, e comparações com SNMPv3 foram realizadas na solução de controle de acesso via XACML. Os testes mostram que, como é tradicional, a segurança tem impacto considerável no tempo de processamento e tráfego na rede. Porém, a arquitetura e implementação realizadas comprovam que, também na área de segurança, a tecnologia de Web Services tem aplicação eficaz para o gerenciamento de redes. / The network management field has several challenges since its beginning. The standard protocol for network management, SNMP, has many drawbacks, related to security, device configuration, and service composition. For these reason, alternative technologies for network management have been investigated. Web Services technology emerged as a strong solution, due to advantages such as employing widely supported standards (HTTP and XML) and service-oriented development model. The first performed investigations in the area showed that Web Services are a valid alternative to SNMP in terms of performance. Thus, Web Services usage in specific areas of network management, such as notifications and management by delegation, have been researched. However, there are currently no studies on security aspects of Web Services-based network management. Web Services enable easy integration of security, which is mandatory for network management, and this is the main goal of this work. An architecture is proposed for security integration in a network management message communication using Web Services. The standards used in this architecture were WSSecurity, which enables security in Web Services, and WS-Management, which targets Web Services-based network management. Access control integration was also developed, using XACML standard. A performance evaluation was carried out in order to verify security usage impact, and comparisons with SNMPv3 were performed in XACML access control solution. Tests showed that, as expected, security has a considerable impact in processing time and network traffic. However, the architecture and implementation show that, also in the security area, the Web Services technology has effective aplication in network management.

Page generated in 0.0382 seconds