41 |
Modelování protokolu PIM-SM v prostředí OMNeT++ / Modelling PIM-SM in OMNeT++Procházka, Tomáš January 2013 (has links)
In this master's thesis I deal with modelling and simulating of multicast routing protocol PIM Sparse Mode in OMNeT++. I also describe basic information about multicast, protocol PIM-SM, its configuration and multicast data streams visualization in computer networks. The thesis is especially focused on design and implementation of PIM-SM in OMNeT++ and extension of ANSAINET library.
|
42 |
Modelování protokolů IS-IS a TRILL / Modelling IS-IS and TRILLMarek, Marcel January 2013 (has links)
In this thesis, we describe the principles of IS-IS routing protocol. We introduce the current state of implementation of this protocol within the simulation framework OMNeT++. We present the implementation of the IS-IS protocol created within the ANSA project. Moreover, we employ its variant called TRILL that is nowadays deployed as replacement of STP in data-center environment. The aim is to enable the modelling of the protocols without the need having to build physical architecture.
|
43 |
Modelování a analýza spolehlivosti počítačové sítě VUT / Modelling and Reliability Analysis of Campus Network at the BUTKraus, Zdeněk January 2011 (has links)
This thesis informs about technologies and architecture of computer network at BUT. It describes chosen technologies and some of theirs variants. Further, it contains simulation model design of a network switch device. That is followed by the model implementation with detailed description of model parts. Then, the model is tested on a set of simulation scenarios and it is evaluated in comparison with theoretical basis and real devices. In conclusion, thesis suggests future model development and improvements.
|
44 |
Diseño e Implementación de un Framework Integrado para Simulaciones de Sistemas Inteligentes de Transporte en OMNeT ++ y Paramics : Memoria para optar al grado de Ingeniero Civil en ComputaciónOlguín Muñoz, Manuel Osvaldo January 2017 (has links)
El presente trabajo de memoria presenta el diseño, implementación y validación de unframework de integración de un simulador de transporte, Quadstone Paramics con un simuladorde redes comunicaciones inalámbricas, OMNeT++, para la simulación y estudio deSistemas Inteligentes de Transporte.Los Sistemas Inteligentes de Transporte surgen como una respuesta a la necesidad de optimización, modernización y mejoramiento de los actuales sistemas de transporte. Los Sistemas de Transporte Inteligente pretenden proveer servicios innovadores que otorguen información a los usuarios y les permitan utilizar el sistema de transporte de manera más segura, coordinada e inteligente. Resulta fundamental la recopilación y transmisión de información enestos sistemas, lo cual se realiza mediante implementación de redes comunicación inalámbrica,tanto entre vehículos como entre vehículos e infraestructura. Es necesario entonces eldesarrollo de entornos de software de modelamiento y simulación de estos sistemas, para suestudio previo a su implementación en el mundo real.Este trabajo de memoria presenta un framework que posibilita la simulación y análisis delos Sistemas Inteligentes de Transporte. PVEINS, como se denomina el software desarrollado,permite el estudio de la integración bidireccional de un sistema de transporte con un sistemade comunicaciones inalámbricas. En ese sentido, el framework permite determinar tanto elimpacto de la comunicación entre vehículos sobre el modelo de transporte, como el impactodel movimiento de los vehículos sobre el medio de comunicación entre estos.Adicionalmente, el presente trabajo de memoria presenta un análisis de eficiencia del softwaredesarrollado, y un estudio para verificar su validez para la simulación de sistemas detransporte de alta complejidad. Los resultados son positivos y demuestran que PVEINS tieneel potencial para posicionarse como una opción competitiva para la simulación de SistemasInteligentes de Transporte en la academia. En particular, se demuestra su eficiencia parasimular grandes sistemas de transporte ejecutando un escenario de 15 minutos de tiemposimulado, con aproximadamente 900 vehículos presentes en la red en cada instante de simulación, en apenas 11 minutos de tiempo real. Se demuestra también su austeridad en uso de recursos del sistema al realizar una simulación con un promedio de 1400 nodos utilizando menos de 600 MB de memoria RAM y menos del 20% de la capacidad total del procesador. Finalmente, se expone su utilidad para el análisis y estudio de Sistemas Inteligentes de Transporte extrayendo información y estadísticas de los escenarios simulados.
|
45 |
New quality of service routing algorithms based on local state information. The development and performance evaluation of new bandwidth-constrained and delay-constrained quality of service routing algorithms based on localized routing strategies.Aldosari, Fahd M. January 2011 (has links)
The exponential growth of Internet applications has created new challenges for the control and administration of large-scale networks, which consist of heterogeneous elements under dynamically changing traffic conditions. These emerging applications need guaranteed service levels, beyond those supported by best-effort networks, to deliver the intended services to the end user. Several models have been proposed for a Quality of Service (QoS) framework that can provide the means to transport these services. It is desirable to find efficient routing strategies that can meet the strict routing requirements of these applications. QoS routing is considered as one of the major components of the QoS framework in communication networks. In QoS routing, paths are selected based upon the knowledge of resource availability at network nodes and the QoS requirements of traffic. Several QoS routing schemes have been proposed that differ in the way they gather information about the network state and the way they select paths based on this information.
The biggest downside of current QoS routing schemes is the frequent maintenance and distribution of global state information across the network, which imposes huge communication and processing overheads. Consequently, scalability is a major issue in designing efficient QoS routing algorithms, due to the high costs of the associated overheads. Moreover, inaccuracy and staleness of global state information is another problem that is caused by relatively long update intervals, which can significantly deteriorate routing performance. Localized QoS routing, where source nodes take routing decisions based solely on statistics collected locally, was proposed relatively recently as a viable alternative to global QoS routing. It has shown promising results in achieving good routing performance, while at the same time eliminating many scalability related problems. In localized QoS routing each source¿destination pair needs to determine a set of candidate paths from which a path will be selected to route incoming flows. The goal of this thesis is to enhance the scalability of QoS routing by investigating and developing new models and algorithms based on the localized QoS routing approach.
For this thesis, we have extensively studied the localized QoS routing approach and demonstrated that it can achieve a higher routing performance with lower overheads than global QoS routing schemes. Existing localized routing algorithms, Proportional Sticky Routing (PSR) and Credit-Based Routing (CBR), use the blocking probability of candidate paths as the criterion for selecting routing paths based on either flow proportions or a crediting mechanism, respectively. Routing based on the blocking probability of candidate paths may not always reflect the most accurate state of the network. This has motivated the search for alternative localized routing algorithms and to this end we have made the following contributions. First, three localized bandwidth-constrained QoS routing algorithms have been proposed, two are based on a source routing strategy and the third is based on a distributed routing strategy. All algorithms utilize the quality of links rather than the quality of paths in order to make routing decisions. Second, a dynamic precautionary mechanism was used with the proposed algorithms to prevent candidate paths from reaching critical quality levels. Third, a localized delay-constrained QoS routing algorithm was proposed to provide routing with an end-to-end delay guarantee. We compared the performance of the proposed localized QoS routing algorithms with other localized and global QoS routing algorithms under different network topologies and different traffic conditions. Simulation results show that the proposed algorithms outperform the other algorithms in terms of routing performance, resource balancing and have superior computational complexity and scalability features. / Umm AlQura University, Saudi Arabia
|
46 |
Performance evaluation of routing protocols for Wireless Mesh NetworksMarinis Artelaris, Spyridon January 2016 (has links)
Wireless Mesh Networks provide an organisation or a community with the means to extend or create a network independent of infrastructure. However, the network’s dynamic topology along with the fact that devices in the network might be mobile and move randomly, brings tolight various kind of problems on the network, with the most common being the routing. In this report, the problem of routing is examined in terms of throughput, routing overhead, end-to-end delay and packet delivery ratio on two chosen algorithms, namely the Dynamic MANET On-demand (DYMO) and the Better Approach To Mobile Adhoc Networking (B.A.T.M.A.N.). Furthermore, this thesis examines also a Transmission Control Protocol (TCP) connection and compares it against several TCP congestion control mechanisms, two of which, were implemented, namely TCP-Illinois and TCP-FIT, to address the effects that different TCP congestion mechanisms have on an ad-hoc network, when reliable connections are needed. The results show that DYMO is more stable, performs good overall and has the lowest routing overhead, however in a situation with limited mobility or no mobility (as in high mobility they perform poorly) proactive protocols like B.A.T.M.A.N. are worthy protocols, should the extra penalty of routing overhead in the network traffic is not causing any problems. Furthermore, regarding the TCP results, it was observed that TCP congestion algorithms designed specifically for Wireless networks, do offer better performance and should be considered, when designing an ad-hoc network.
|
47 |
Enhanced communication security and mobility management in small-cell networksNamal, S. (Suneth) 09 December 2014 (has links)
Abstract
Software-Defined Networks (SDN) focus on addressing the challenges of increased complexity and unified communication, for which the conventional networks are not optimally suited due to their static architecture.
This dissertation discusses the methods about how to enhance communication security and mobility management in small-cell networks with IEEE 802.11 backhaul. Although 802.11 has become a mission-critical component of enterprise networks, in many cases it is not managed with the same rigor as the wired networks. 802.11 networks are thus in need of undergoing the same unified management as the wired networks.
This dissertation also addresses several new issues from the perspective of mobility management in 802.11 backhaul. Due to lack of built-in quality of service support, IEEE 802.11 experiences serious challenges in meeting the demands of modern services and applications. 802.11 networks require significantly longer duration in association compared to what the real-time applications can tolerate. To optimise host mobility in IEEE 802.11, an extension to the initial authentication is provided by utilising Host Identity Protocol (HIP) based identity attributes and Elliptic Curve Cryptography (ECC) based session key generation.
Finally, this dissertation puts forward the concept of SDN based cell mobility and network function virtualization, its counterpart. This is validated by introducing a unified SDN and cognitive radio architecture for harmonized end-to-end resource allocation and management presented at the end. / Tiivistelmä
Ohjelmisto-ohjatut verkot (SDN) keskittyvät ratkaisemaan haasteita liittyen kasvaneeseen verkkojen monimutkaisuuteen ja yhtenäiseen kommunikaatioon, mihin perinteiset verkot eivät staattisen rakenteensa vuoksi sovellu.
Väitöskirja käsittelee menetelmiä, joilla kommunikaation turvallisuutta ja liikkuvuuden hallintaa voidaan parantaa IEEE 802.11 langattomissa piensoluverkoissa. Vaikkakin 802.11 on muodostunut avainkomponentiksi yritysverkoissa, monissa tapauksissa sitä ei hallinnoida yhtä täsmällisesti kuin langallista verkkoa. 802.11 verkoissa on näin ollen tarve samantyyppiselle yhtenäiselle hallinnalle, kuin langallisissa verkoissa on.
Väitöskirja keskittyy myös moniin uusiin liikkuvuuden hallintaan liittyviin ongelmiin 802.11 verkoissa. Johtuen sisäänrakennetun yhteyden laatumäärittelyn (QoS) puuttumisesta, IEEE 802.11 verkoille on haasteellista vastata modernien palvelujen ja sovellusten vaatimuksiin. 802.11 verkot vaativat huomattavasti pidemmän ajan verkkoon liittymisessä, kuin reaaliaikasovellukset vaativat. Työssä on esitelty laajennus alustavalle varmennukselle IEEE 802.11-standardiin isäntälaitteen liikkuvuuden optimoimiseksi, joka hyödyntää Host Identity Protocol (HIP)-pohjaisia identiteettiominaisuuksia sekä elliptisten käyrien salausmenetelmiin (ECC) perustuvaa istunnon avaimen luontia.
Lopuksi työssä esitellään ohjelmisto-ohjattuihin verkkoihin pohjautuva solujen liikkuvuuden konsepti, sekä siihen olennaisesti liittyvä verkon virtualisointi. Tämä validoidaan esittelemällä yhtenäinen SDN:ään ja kognitiiviseen radioon perustuva arkkitehtuuri harmonisoidulle päästä päähän resurssien varaamiselle ja hallinnoinnille, joka esitellään lopussa.
|
48 |
Porovnání simulačních prostředí pro analýzu bezdrátových technologií / Comparison of simulation environments for analysis of wireless technologyRimeg, Martin January 2020 (has links)
This work is focused on the issue of wireless networks according to the IEEE 802.11 standard. The main subject of research is the Rate Adaptation Algorithms (RAA). The work also contains a description of simulation environments NS-3 and OMNeT in terms of adaptation algorithms. At the end of the work there is a summary of wireless network simulations in NS-3 and OMNeT environments and their comparison with the actual measurement of network parameters.
|
49 |
Modelování a simulace spanning-tree protokolů / Modeling and Simulation of Spanning-Tree ProtocolPoláčeková, Simona January 2021 (has links)
This term project deals with the functionality of Spanning Tree protocols, especially the Rapid Spanning Tree Protocol, and the Multiple Spanning Tree Protocol. The primary usage of spanning tree protocols is the prevention of loops within the data link layer, the prevention of a broadcast storm, and also dealing with redundancy in the network. Moreover, the project contains the description of configuration of these protocols on Cisco devices. The main goal of this thesis is to implement the Multiple Spanning Tree protocol into INET framework within the OMNeT++ simulation system. Then, the implemented solution is tested and it's functionality is compared with the referential behavior in a Cisco network.
|
50 |
Modelování protokolů pro redundanci brány / Modelling Gateway Redundancy ProtocolsVítek, Petr January 2013 (has links)
This master's thesis report deals with the theoretical analysis of FHRP. First Hop Redundancy Protocols are network protocols which are designed to protect the default gateway and also to ensure high availability in the network by using redundancy. The reader becomes familiar with protocols VRRP, HSRP and GLBP and also learn the way how to configure them to on real Cisco devices. It also describes how implement VRRP int the simulated enviroment of OMNeT++. The result of the implementation is verified in the test topologies.
|
Page generated in 5.8031 seconds