Made available in DSpace on 2014-06-12T15:59:17Z (GMT). No. of bitstreams: 2 arquivo4992_1.pdf: 465621 bytes, checksum: beb55c17d095bd73e42ae404d38057fa (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2002 / A crescente demanda e o explosivo crescimento da Internet está impondo novos desafios para a garantia de serviços em termos de performance, confiabilidade e Qualidade de Serviço (QoS). Muitas aplicações de missão crítica que dependem das tecnologias de rede não podem funcionar sem garantias expressas de entrega. Entretanto, as redes de dados atuais não oferecem nenhuma garantia de que as exigências feitas a nível de serviço possam ser garantidas sem algum tipo de degradação a qualquer hora, do dia ou da noite, a despeito de outros usuários da rede. Para atender essas exigências, a infra-estrutura da rede precisa ser melhorada com novas tecnologias que ofereçam aos operadores de rede ferramentas para controlar o comportamento da mesma. Juntas, as capacidades oferecidas pela Engenharia de Tráfego, pelo MPLS (Multiprotocol Label Switching) e pelo DiffServ possibilitam o controle e o balanceamento de carga na rede necessários à entrega de serviço de acordo com contratos personalizados. Este trabalho apresenta o MPLS associado à Engenharia de Tráfego como solução para o problema de alocação ineficiente dos recursos em uma rede e o conseqüente congestionamento provocado por tal problema. O esquema de encaminhamento de pacotes do MPLS é empregado como estratégia para minimizar o congestionamento ou alternativamente maximizar a utilização dos recursos, através da alocação eficiente dos mesmos, garantindo, num ambiente com diferenciação de serviço, uma melhor Qualidade de Serviço em termos de redução na perda de pacotes, no atraso e na variação de atraso, e no aumento da vazão agregada

Táto diplomová práca sa zaoberá technickou realizáciou WBAN zariadenia, ktoré je schopné súbežne komunikovať prostredníctvom dvoch bezdrôtových komunikačných protokolov. Rešerš dostupných riešení je dostupná s hodnotením jednotlivých produktov podľa vopred stanovených kritérií. Návrh z hľadiska software obsahuje tvorbu vlastného BLE servisu, konfiguráciu Timeslot API a periférií často využívaných vo WBAN zariadeniach. Výroba dosiek plošných spojov pre zariadenie a dedikovaný ovládač zahŕňa vlastnú anténu, nabíjací obvod batérie a nRF52810 čip. Testovanie prototypov je zhrnuté v poslednej kapitole spoločne s experimentálnym meraním útlmu živočíšneho tkaniva.

Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: MPLS-based recovery is intended to effect rapid and complete restoration of traffic affected by a fault in a Multiprotocol Label Switching (MPLS) network. Two MPLS-based recovery models have been proposed: lP re-routing which establishes recovery paths on demand, and protection switching which works with pre-established recovery paths. lP re-routing is robust and frugal since no resources are pre-committed but it is inherently slower than protection switching which is intended to offer high reliability to premium services where fault recovery takes place at the 100 ms time scale. This thesis presents an overview of various recovery techniques and addresses the problem of how to find an in some sense optimal set of pre-established traffic engineered recovery paths, given a network with link capacities and traffic demands. We present and motivate our choice of a nonlinear objective function and optimization method for finding traffic engineered working and recovery paths. A variant of the flow deviation method is used to find and capacitate a set of optimal label switched paths. We present and evaluate two simple methods for computing a set of pre-established traffic engineered recovery paths by using the flow deviation method. / AFRIKAANSE OPSOMMING: MPLS-gebaseerde herstel is daarop gemik om verkeer wat deur 'n fout in 'n Multiprotokol Etiketwisseling (Multiprotocol Label Switching) (MPLS) netwerk geaffekteer is, vinnig en volledig te herstel. Twee MPLS-gebaseerde herstelmodelle is voorgestel: Internetprotokol-herroetering (lP rerouting) wat herstelpaaie op aanvraag tot stand bring, en beskermingsoorskakeling (protection switching) wat met voorafbeplande herstelpaaie werk. IP-herroetering is robuust en voordelig aangesien geen netwerkbronne vooraf gereserveer word nie, maar dit is inherent stadiger as beskermingsoorskakeling wat veronderstel is om 'n hoë graad van betroubaarheid aan belangrike dienste te bied waar die herstel van foute in die 100 ms tydskaal plaasvind. Hierdie tesis verskaf 'n oorsig oor verskeie hersteltegnieke en ondersoek die probleem hoe om 'n optimale versameling van voorafbeplande herstelpaaie te vind, gegee 'n netwerk met skakelkapasiteite (link capacities) en verwagte netwerkverkeer. Ons stel voor en motiveer ons keuse van 'n nie-lineêre objekfunksie en optimeringsmetode om verkeersontwerpde (traffic engineered) aktiewe en herstelpaaie te vind. 'n Variant van die vloeideviasie (flow deviation)-metode word gebruik om 'n optimale versameling van etiketwisseling (label switched) paaie te vind en om 'n optimale hoeveelheid kapasiteit aan die paaie toe te ken. Ons stel voor en evalueer twee eenvoudige metodes om 'n versameling van optimale voorafbeplande herstelpaaie te bereken deur die vloeideviasie-metode toe te pas.

Many reports have been written about the techniques behind Virtual Private Networks (VPN) and Multi Protocol Label Switching (MPLS). They usually deal with the low level design of the software implementing a specific technique. The initial products are usually not mature enough to run in a large network or have to be adjusted in some way to fit. This report investigates the different ways of implementing strict layer 2 Virtual Private Networks in an existing nation-wide Gigabit Ethernet. The infrastructure in use, as well as the hardware, has to be used without major changes. Since 1998/1999, when MPLS first started in the laboratories, development has continued. Today it is possible to introduce MPLS or tunneled national virtual local area network into an existing network. This requires high speed, fault tolerant, and stable hardware and software. Going beyond the separation of traffic at layer 3 using Virtual Private Networks, i.e., IPSec, we can tunnel layer 2 traffic through a network. Although the first layer 3 VPN products are already in use, layer 2 VPNs still need to be evaluated and brought into regular use. There are currently two ways of tunneling VLANs in a core network: tunneled VLANs (or as Extreme Networks calls them, VMANs) and MPLS. This project showed that it is possible to start with a VLAN-only solution, and then upgrade to MPLS to solve scalability issues. The VMAN solution can not be used at Arrowhead, since there are too many disadvantages in the way Extreme Networks has implemented it. However, a mix of tunneling VMAN in a VLAN core is possible, and enables customer tagging of VLANs in a Layer 2 VPN. Furthermore, the testing of EAPS and per-VLAN Spanning Tree Protocol turned out well, and showed that EAPS should not be used when there is more than one loop.

Software-Defined Wide Area Networks is a technology that has received a lot of attention in recent years. The technology enables direct Internet access without having to direct traffic through a data center. It also enables the use of less expensive Internet connections to build the Wide-Area Network, expensive Multiprotocol LabelSwitchingconnectionsarenolongernecessary. This results in greater responsibility for enterprises when it comes to ensuring performance within the network, where the previous dedicated links with a guaranteed performance by Internet Service Provider have been replaced with unpredictable best-effort connections. The project targets the challenges Software-Defined Wide Area Networks introduces in terms of monitoring, by examining the required network transparency between Wide-Area Network edges. A selection of Network Management Systems was evaluated with the requirements specification as a basis. The results show that more diligent monitoring at the edges is needed. Visibility into the underlay network, providing transportation, has to be available. Where the enterprises need to be able to examine path-selection of traffic per application. To ensure that the root of problems can be located in case of performance issues. This was not obtained by the evaluated Network Management Systems. Moreover, it turned out that there was no common standard available for monitoring the technology at the time of the project. The lack of knowledge in the field aimed to decrease with the degree project and the result is of greatest interest to companies that have made the transition to Software-Defined Wide Area Networks or are about to do so. / Software-Defined Wide Area Networks är en teknik som har fått mycket uppmärksamhet de senaste åren. Tekniken möjliggör direkt internetåtkomst utan att behöva dirigera trafik genom datacentret. Det möjliggör också användningavbilligareinternetanslutningar för att bygga Wide-AreaNetwork, dyra Multiprotocol Label Switching anslutningar är inte längre nödvändiga. Detta resulterar i ett större ansvar för företag när det gäller att säkerställa prestanda inom nätverket, där de tidigare dedikerade länkarna med garanterad prestanda av internetleverantörer har ersatts med oförutsägbara anslutningar som skickar trafik efter bästa förmåga. Examensarbetet riktar sig mot de utmaningar som Software-Defined Wide Area Networks innebär när det gäller övervakning, genom att undersöka den nödvändiga nätverkstransparensen mellan Wide-Area Network kanterna. Ett urval av nätverkshanteringssystem utvärderades med en definierad kravspecifikation som grund. Resultaten visar att det behövs mer noggrann övervakning i Wide-Area Network kanterna. Insyn i transportlagret måste vara tillgänglig och företagen behöver kunna granska vägval av trafik per applikation, för att säkerställa att ursprungsfel går att lokaliseras i händelse av prestandaproblem. Detta erhölls inte av de utvärderade nätverkshanteringssystemen. Det visade sig dessutom att det inte fanns någon gemensam standard tillgänglig för övervakning av tekniken vid tidpunkten för examensarbetet. Examensarbetet syftar till att minska kunskapsbristen inom området och resultatet är av störst intresse för företag som gjort övergången till Software-Defined Wide Area Networks eller är på väg att göra det.

En la presente tesina se realiza una descripción de la tecnología de Conmutación Multi-Protocolo mediante etiquetas usando una red privada virtual para la comunicación de una entidad empresarial. Se realizó una descripción de la tecnología MPLS con VPN mostrando sus cualidades, ventajas y desventajas, se promueve la esta tecnología a la red de comunicación de datos de la empresa tenga un performance y confidencialidad en los datos transmitidos, diseñando un esquema así como la infraestructura que podría ser usada en esta implementación, con características modulares las cuales permitirá a la empresa ir creciendo a la medida de que su tráfico o demanda de transporte vaya aumentando al igual que la integración de las demás extensiones se amerita el caso; para el diseño nos ayudaremos del programa de simulación “GNS3” el mismo que se hará un bosquejo de la configuración y modelo para la transmisión de sucursal a matriz y viceversa. This thesis is a description of MPLS VPN using a communication from the business entity. Was a description of MPLS VPN showing his qualities, advantages and disadvantages, promotes the introduction of this technology to the data communication network of the company to have a performance traffic and confidentiality of the data transmitted, designing scheme as well as the infrastructure that could be used in this implementation, modular features which allow the company to grow to the extent that their traffic and transport demand will increase as the integration of other extensions are merited case, to help us design simulation program "GNS3" the same to be made a sketch of the model configuration and transmission branch to parent and vice versa.

Made available in DSpace on 2016-03-15T19:38:15Z (GMT). No. of bitstreams: 1 Gustavo de Melo Valeira.pdf: 5235384 bytes, checksum: b73ab4b64760275d30c77ef2e8a779c1 (MD5) Previous issue date: 2010-06-25 / The purpose of this work is the development of a transmission platform with a graphical interface and software, using a TV channel of Brazilian Digital Television Standard (SBTVD) to transmit encapsulated data, audio and video. Initially is presented the SBTVD, with major highlight for multiplexing, given its importance in identifying and decoding the received signal. Within the transmitted bitstream there are certain tables that are responsible for identifying the information type present in the channel, being the most important detailed in this work. To make easy this configuration is presented the graphical interface to configure a channel in two situations: encapsulated data in ethernet format and audio/video content. Beside this, are compared the efficiencies of utilizing the packing control of multiprotocol encapsulation, that is used to transmit data in ethernet format. Also is presented an exploratory study of efficiency of bit rate related with the addition of the necessary headers to transmit correctly the signal in ethernet format inside the SBTVD transport protocol. / O objetivo deste trabalho é o desenvolvimento de uma plataforma de transmissão com interface gráfica e software, utilizando um canal de TV do Sistema Brasileiro de TV Digital (SBTVD) para a transmissão de dados encapsulados, áudio e vídeo. Inicialmente é apresentado o SBTVD, com maior destaque para a multiplexação, haja vista a sua importância na identificação e decodificação do sinal recebido. Dentro do fluxo de bits transmitido existem certas tabelas que são responsáveis pela identificação dos tipos de informação presentes no canal, sendo as mais importantes detalhadas neste trabalho. Para facilitar essa configuração é apresentada a interface gráfica para configurar um canal em duas situações: dados encapsulados no formato ethernet e conteúdo de áudio/vídeo. Além disso, são comparadas as eficiências da utilização do controle de empacotamento do encapsulamento multiprotocolo, que é usado para transmitir dados no formato ethernet. Também é apresentado um estudo exploratório da eficiência da taxa de bits relacionada com a adição dos cabeçalhos necessários para transmitir corretamente o sinal no formato ethernet dentro do protocolo de transporte do SBTVD.

Multiprotocol Label Switching (MPLS) is a new paradigm in routing architectures which has changed the way Internet Protocol (IP) packet is transferred in a Network. MPLS ensures the reliability of the communication minimizing the delays and enhancing the speed of packet transfer. One important feature of MPLS is its capability of providing Traffic Engineering (TE) which plays a vital role for minimizing the congestion by efficient load, balancing and management of the network resources. The performance evaluation is done considering the network parameters latency, jitter, packet end to end delay, and packet delay variation. Integration of QoS with the MPLS-TE network may enhance the performance of the network. Various scheduling algorithms can be used for implementing QoS on a network, which may vary the performance of the network. In our study, QoS is implemented on top of the MPLS-TE network using Differentiated Service (DiffServ) architecture. Different basic scheduling algorithms are used for the implementation of QoS and to check their impact on the network and to identify the suitable one among them. Performance evaluation is done considering the network parameters latency, jitter, packet end-to-end delay, and Packet Delay Variation. The simulation was done using OPNET modeler 16.0 and the results were analyzed. The simulation result shows that using TE along with QoS in MPLS network decreases the latency, jitter, packet delay variation and end to end packet delay compared to using TE alone for voice traffic. / +46738732963

Multiprotocol Label Switching (MPLS) is an emerging technology which ensures the reliable delivery of the Internet services with high transmission speed and lower delays. The key feature of MPLS is its Traffic Engineering (TE), which is used for effectively managing the networks for efficient utilization of network resources. Due to lower network delay, efficient forwarding mechanism, scalability and predictable performance of the services provided by MPLS technology makes it more suitable for implementing real-time applications such as voice and video. In this thesis performance of Voice over Internet Protocol (VoIP) application is compared between MPLS network and conventional Internet Protocol (IP) network. OPNET modeler 14.5 is used to simulate the both networks and the comparison is made based on some performance metrics such as voice jitter, voice packet end-to-end delay, voice delay variation, voice packet sent and received. The simulation results are analyzed and it shows that MPLS based solution provides better performance in implementing the VoIP application. In this thesis, by using voice packet end-to-end delay performance metric an approach is made to estimate the minimum number of VoIP calls that can be maintained, in MPLS and conventional IP networks with acceptable quality. This approach can help the network operators or designers to determine the number of VoIP calls that can be maintained for a given network by imitating the real network on the OPNET simulator. / 0046737675303

The subject of this thesis is to study available security protocols and tools for their verification. The first part is devoted to briefly describe the concepts related to the area of security protocols and verification logics. The second part directly lists various protocols, along with attacks and errors found in design. Next chapter describes the most important tools for automatic analysis of security protocols in more detail. The main part deals with verification of security protocols selected in the chosen tool called Scyther. In conclusion, examples of multiprotocol attacks along with a summary table are displayed.