• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 59
  • 19
  • 16
  • 14
  • 10
  • 8
  • 7
  • 6
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 162
  • 61
  • 42
  • 40
  • 38
  • 38
  • 32
  • 30
  • 28
  • 28
  • 28
  • 27
  • 22
  • 17
  • 17
  • 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.
61

Hlasová služba v integrovaných sítích / Voice Service in Integrated Networks

Yeftsifeyeu, Aliaksandr January 2014 (has links)
The master’s thesis presents routing protocols, SIP handshake, describes modern VoIP networks and its features. Thesis is primary focused on networks with integrated MPLS. The most known advantages and disadvantages were described of modern network based on such technology. Further, networks and a router with installed Cisco Call Manager Express 7.1 were configured, which is provided by CISCO. For recreating of fully working telephone network IP PBX10 has been used from SMC Networks. For connection between different phones within these integrated networks, SIP trunk was configured on SMC PBX10 as well as on router, which is connecting three configured Cisco IP phones. Each phone has its own number according to the dial plan. For calls from one network to another the special pattern has been established, so the number of each caller can be easily identified by added digit. On one of the CISCO routers was shown a configuration of MPLS and OSPF protocols. With an analyzer VePAL TX300e, the lab network has been measured to analyze QoS parameters of the network according to standard RFC 2544. Thesis also gives references to lab devices, which have been used accordingly to the work.
62

Méthodes d'autoréparation proactives pour les réseaux d'opérateurs / Proactive self-healing methods for carrier networks

Vidalenc, Bruno 28 June 2012 (has links)
Les opérateurs de réseaux de télécommunications accordent une importance toute particulière à la gestion des pannes. L’implication de l'humain dans la prise de décision et l'analyse d'une quantité énorme d'alarmes et d'informations, ainsi que le caractère réactif des mécanismes de gestion des pannes, ne permettent pas la réactivité nécessaire à une gestion optimale des incidents. Pour pallier ce problème, cette thèse s'intéresse à des mécanismes proactifs qui anticipent les pannes afin d'améliorer l'efficacité de leur gestion. La mise en oeuvre, dans les équipements, de composants autonomes capables d'analyser en permanence l'état de santé du réseau permettrait de fournir une information en temps réel sur le risque de panne, nécessaire au déploiement de nouveaux mécanismes d'autoréparation proactifs. La première partie de cette thèse est donc consacrée à la définition des composants architecturaux indispensables à l'introduction de fonctions d'autoréparation proactives. Dans un deuxième temps, nous étudions et analysons en détail trois mécanismes d'autoréparation proactifs exploitant une information de risque de panne. Le premier mécanisme a pour objectif d'accélérer la convergence des protocoles de routage à état de lien en adaptant la fréquence d'envoi des messages de détection de pannes en fonction du risque de panne. Le deuxième mécanisme modifie dynamiquement les métriques de routage afin de détourner le trafic des équipements risqués et de minimiser l'impact d'une panne sur le trafic. Enfin, le dernier mécanisme s'attache aux dispositifs de protection et de restauration du protocole GMPLS afin d'adapter dynamiquement la consommation des ressources, aux risques encourus / Network providers attach a significant focus to fault-management. Indeed, availability and quality of service are highly important parameters in the competition between networks operators. Tthe involvement of human in the decision making process and the analyzing a huge amount of alarms and information, as well as the reactive nature of fault management mechanisms, do not allow the required reactivity for optimal management of incidents. This thesis focuses on proactive mechanisms which anticipate failures to improve the effectiveness of their management. Indeed, the failures are often preceded by alarms or symptomatic behaviors. Implementation, in equipment, of autonomous components capable of continuously analyzing the network health would enable to provide a real-time risk of failure information, required to deploy new proactive self-healing mechanisms. The first part of this thesis is devoted to the definition of architectural components necessary for the introduction of proactive self-healing functions. Then, in a second step, we study and analyze in detail three self-healing mechanisms exploiting a proactive risk-level of failure information. The first mechanism is designed to accelerate the convergence of link-state routing protocols by adjusting the frequency of sending failure detection messages function of the risk-level. The second mechanism dynamically tunes routing metrics in order to divert traffic flows from risky equipment and to minimize the failure incidence on traffic. Finally, the last proposition is dedicated to the recovery mechanisms of GMPLS protocol by dynamically adapting the resources consumption of recovery to the involved risks
63

Vergleich von QoS- und Mobilitätsmechanismen in Backhaul-Netzen für 4G Mobilfunk

Windisch, Gerd 03 August 2012 (has links) (PDF)
Die vorliegende Diplomarbeit behandelt den Vergleich von QoS- und Mobilitätsmechanismen in der LTE/SAE-Architektur. Nach der Einführung in die LTE/SAE-Architektur wird dargestellt, wie die QoS und die Mobilität im Standard des 3GPP gewährleitet wird. Danach erfolgt eine Untersuchung der Technologien PMIP, Ethernet und MPLS, ob sie sich als Alternativen für die standardisierten Mechanismen eignen. In einem weiteren Kapitel wird ein eigenes Konzept zur QoS- und Mobilitätsverwaltung vorgestellt, und es erfolgen erste Betrachtungen. Abschließend wird ein Ausblick gegeben, wie das vorgestellte eigene Konzept weiter ausgebaut werden könnte.
64

Especifica??o de uma rede MPLS fim-a-fim com diferencia??o de servi?os

Silva Neto, Edson Moreira 02 August 2006 (has links)
Made available in DSpace on 2014-12-17T14:55:03Z (GMT). No. of bitstreams: 1 EdsonMSN.pdf: 1297152 bytes, checksum: ddeef5119a3b863368e35112b7fbbd68 (MD5) Previous issue date: 2006-08-02 / New multimedia applications that use the Internet as a communication media are pressing for the development of new technologies, such as: MPLS (Multiprotocol Label Switching) and DiffServ. These technologies introduce new and powerful features to the Internet backbone, as the provision of QoS (Quality of Service) capabilities. However, to obtain a true end-to-end QoS, it is not enough to implement such technologies in the network core, it becomes indispensable to extend such improvements to the access networks, what is the aim of the several works presently under development. To contribute to this process, this Thesis presents the RSVP-SVC (Resource Reservation Protocol Switched Virtual Connection) that consists in an extension of RSVP-TE. The RSVP-SVC is presented herein as a mean to support a true end-to-end QoS, through the extension of MPLS scope. Thus, it is specified a Switched Virtual Connection (SVC) service to be used in the context of a MPLS User-to-Network Interface (MPLS UNI), that is able to efficiently establish and activate Label Switched Paths (LSP), starting from the access routers that satisfy the QoS requirements demanded by the applications. The RSVP-SVC was specified in Estelle, a Formal Description Technique (FDT) standardized by ISO. The edition, compilation, verification and simulation of RSVP-SVC were made by the EDT (Estelle Development Toolset) software. The benefits and most important issues to be considered when using the proposed protocol are also included / O protocolo proposto nesta Tese, denominado Resource Reservation Protocol Switched Virtual Connection (RSVP-SVC), que consiste numa extens?o do RSVP-TE, vai de encontro ao surgimento de novas aplica??es multim?dia, que usam a Internet como meio de interconex?o. Tais aplica??es pressionam pelo desenvolvimento de novas tecnologias, tais como: MPLS, DiffServ e RSVP-TE, que introduzem novas e eficientes caracter?sticas ao backbone Internet, proporcionando uma significativa diferen?a no que tange ? provis?o de QoS (Quality of Service). O presente trabalho leva em conta o fato de que para se conseguir uma QoS fim-a-fim verdadeira, n?o basta implementar tais tecnologias no n?cleo da rede, ? imprescind?vel, estender tais melhorias ?s redes de acesso e qui?? ?s redes locais. Nesse sentido, muitos trabalhos est?o atualmente em desenvolvimento. ? no intuito de contribuir com este processo que este trabalho apresenta a defini??o de uma UNI MPLS SVC atrav?s do RSVP-SVC. Essa extens?o d? ao RSVP-TE a capacidade de estabelecer t?neis LSP (Label Switched Path) a partir de conex?es discadas, ampliando portanto o escopo de utiliza??o do MPLS, levando-o at? ?s redes locais atrav?s das redes de acesso, e provendo tamb?m suporte a uma QoS fim-a-fim verdadeira. O RSVP-SVC foi especificado em Estelle, que ? uma linguagem de especifica??o formal padronizada pela ISO. A edi??o, compila??o, verifica??o e simula??o do RSVP-SVC foi feita atrav?s do programa EDT (Estelle Development Toolset). Ademais, tanto os benef?cios quanto ?s quest?es mais importantes a serem consideradas quando do uso deste protocolo s?o apresentados
65

Migración e implementación hacia una red MPLS-VPN aplicado a una entidad empresarial en la ciudad de Lima

Castillo Meza, Joel Omar January 2015 (has links)
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.
66

OPNET Analysis of VoIP over MPLS VPN with IP QoS / OPNET Analys av VoIP över MPLS VPN med IP QoS

Rana, Bilal Zahid, Ali, Shahid January 2011 (has links)
There are many disadvantages (cost, lack of security, difficult to manage large networks, support to non-sensitive applications, delay, etc.) associated with traditional networking, IP network, ATM and Frame relay networking. To solve this, an MPLS-based VPN networking is introduced that can work with existing deployed backbones and allow organizations to interconnect the dispersed sites and remote workers through secure links by using public internet. In this thesis, we are trying to build a better understanding to MPLS VPN and we researched to analyze the behavior of OSPF and RIPv2 based MPLS-BGP VPN architectures by using intense VoIP traffic. Then it comes with an OPNET simulation process and scenarios for MPLS-BGP VPN. At last, the conclusion is made: OSPF based MPLS-BGP VPN architecture has lower VPN delay, background traffic Flow delay, LSP delay and point-to-point Queuing delay, and has better performance in VPN load and VPN throughput that can acquire customer satisfaction and confidence as compared to the RIPv2 based MPLS-BGP VPN architecture. / Det finns många nackdelar (kostnader, bristande säkerhet, svåra att hantera stora nätverk, stöd till icke-känsliga tillämpningar, delay, etc.) i samband med traditionella nätverk, IP-nätverk, ATM och Frame Relay nätverk. För att lösa detta, är ett MPLS-baserat VPN nätverk införs som kan arbeta med befintliga sättas samman och låter organisationer för att förbinda de spridda platser och distansarbetare genom säkra länkar genom att använda publika Internet. I denna avhandling försöker vi bygga en bättre förståelse för MPLS VPN och vi forskat för att analysera beteendet hos OSPF och RIPv2 baserad MPLS-VPN BGP arkitekturer med hjälp av intensiv VoIP-trafik. Då kommer med en OPNET simulering process och scenarier för MPLS-BGP VPN. Äntligen är den slutsatsen: OSPF bygger MPLS-VPN BGP arkitektur har lägre VPN dröjsmål bakgrund trafikflödet dröjsmål, LSP dröjsmål och punkt-till-punkt Queuing dröjsmål, och har bättre prestanda i VPN-belastning och VPN som kan få kunden tillfredsställelse och förtroende jämfört med RIPv2 baserad MPLS-VPN BGP arkitektur.
67

Vergleich von QoS- und Mobilitätsmechanismen in Backhaul-Netzen für 4G Mobilfunk

Windisch, Gerd 17 November 2008 (has links)
Die vorliegende Diplomarbeit behandelt den Vergleich von QoS- und Mobilitätsmechanismen in der LTE/SAE-Architektur. Nach der Einführung in die LTE/SAE-Architektur wird dargestellt, wie die QoS und die Mobilität im Standard des 3GPP gewährleitet wird. Danach erfolgt eine Untersuchung der Technologien PMIP, Ethernet und MPLS, ob sie sich als Alternativen für die standardisierten Mechanismen eignen. In einem weiteren Kapitel wird ein eigenes Konzept zur QoS- und Mobilitätsverwaltung vorgestellt, und es erfolgen erste Betrachtungen. Abschließend wird ein Ausblick gegeben, wie das vorgestellte eigene Konzept weiter ausgebaut werden könnte.
68

Performance Analysis of an SD-WAN Infrastructure Implemented Using Cisco System Technologies

Moser, Gianlorenzo January 2021 (has links)
Software-Defined Wide Area Networking (SD-WAN) is an emerging technology that has the potential to satisfy the increasing demand for reliable and efficient Wide Area Networks (WANs) in the enterprise-network market. This thesis focuses on the main features of an SD-WAN network and on the technical challenges facing the design and implementation of an SD-WAN infrastructure. It also provides a detailed comparison between the SD-WAN and the otherWANs solutions such as MultiProtocol Label Switching (MPLS). The thesis is based on the project that is about the migration of network infrastructure that uses the MPLS technology to a network infrastructure that uses the SD-WAN technology. The migration process includes many phases such as the analysis of the existing MPLS based infrastructure, identification of suitable appliances based on customer requests, and the design of the SD-WAN infrastructure that can be implemented without disrupting the network functioning during the transition stage. The thesis provides a detailed description of these steps and it discusses the trade-offs that were made during the design phase of the project. The results presented in the thesis are obtained through on-site tests performed for the new SD-WAN infrastructure. The tests were performed with the objective to evaluate some of the main SD-WAN functionalities such as load balancing, traffic shaping, and high availability. The obtained results show the effective functioning of the network infrastructure and illustrate some of the main advantages that the new SD-WAN infrastructure has over the old MPLS infrastructure. Finally, this thesis could be of interest to network professionals and employees who consider SD-WAN as a possible solution for their company’s business. / Software-Defined Wide Area Networking (SD-WAN) är en framväxande teknik som har potential att tillgodose den ökande efterfrågan på tillförlitliga och effektiva Wide Area Networks (WAN) på företagsnätverksmarknaden. Denna avhandling fokuserar på huvudfunktionerna i ett SD-WAN-nätverk och på de tekniska utmaningarna för design och implementering av en SD-WAN-infrastruktur. Det ger också en detaljerad jämförelse mellan SD-WAN och andra WAN-lösningar som MultiProtocol Label Switching (MPLS). Avhandlingen bygger på projektet som handlar om migrering av nätverksinfrastruktur som använder MPLS-tekniken till en nätverksinfrastruktur som använder SD-WAN-tekniken. Migreringsprocessen omfattar många faser, till exempel analys av befintlig MPLS-baserad infrastruktur, identifiering av lämpliga apparater baserat på kundförfrågningar och utformningen av SD-WAN-infrastrukturen som kan implementeras utan att nätverket fungerar under övergångssteget. Avhandlingen ger en detaljerad beskrivning av dessa steg och diskuterar de avvägningar som gjordes under projektets designfas. Resultaten som presenteras i avhandlingen erhålls genom test på plats för den nya SD-WAN-infrastrukturen. Testerna utfördes i syfte att utvärdera några av de viktigaste SD-WAN-funktionerna som lastbalansering, trafikformning och hög tillgänglighet. De erhållna resultaten visar att nätinfrastrukturen fungerar effektivt och illustrerar några av de största fördelarna som den nya SD-WAN-infrastrukturen har jämfört med den gamla MPLS-infrastrukturen. Slutligen kan denna avhandling vara av intresse för nätverkspersonal och anställda som anser SD-WAN som en möjlig lösning för företagets verksamhet.
69

Optimisation dynamique de réseaux IP/MPLS / Dynamic optimization of IP/MPLS networks

Vallet, Josselin 05 May 2015 (has links)
La forte variabilité des trafics est devenue l'un des problèmes majeurs auxquels doivent faire face les gestionnaires d'infrastructures réseau. Dans ces conditions, l'optimisation du routage des flux en se basant uniquement sur une matrice de trafic moyenne estimée en heure de pointe n'est plus pertinente. Les travaux conduits dans cette thèse visent la conception de méthodes d'optimisation dynamiques du routage, adaptant en temps réel les routes utilisées par les flux aux conditions de trafic dans le réseau.Nous étudions tout d'abord le problème d'optimisation des poids OSPF pour le routage intra-domaine dans les réseaux IP, où le trafic est routé le long de plus courts chemins, en fonction des poids des liens. Nous proposons une approche en ligne permettant de reconfigurer dynamiquement les poids OSPF, et donc les routes utilisées, pour répondre aux variations observées du trafic et réduire ainsi le taux de congestion du réseau. L'approche proposée repose sur l'estimation robuste des demandes en trafic des flux à partir de mesures SNMP sur la charge des liens. Les résultats expérimentaux, aussi bien sur des trafics simulés que réels, montrent que le taux de congestion du réseau peut être significativement réduit par rapport à une configuration statique.Dans la même optique, nous nous intéressons également à l'optimisation des réseaux MPLS, qui permettent de gérer l'utilisation des ressources disponibles en affectant un chemin spécifique à chaque LSP. Nous proposons un algorithme inspiré de la théorie des jeux pour déterminer le placement des LSP optimisant un critère de performance non linéaire. Nous établissons la convergence de cet algorithme et obtenons des bornes sur son facteur d'approximation pour plusieurs fonctions de coût. L'intérêt principal de cette technique étant d'offrir des solutions de bonne qualité en des temps de calcul extrêmement réduits, nous étudions son utilisation pour la reconfiguration dynamique du placement des LSP.La dernière partie de cette thèse est consacrée à la conception et au développement d'une solution logicielle permettant le déploiement d'un réseau overlay auto-guérissant et auto-optimisant entre différentes plateformes de cloud computing. La solution est conçue pour ne nécessiter aucun changement des applications. En mesurant régulièrement la qualité des liens Internet entre les centres de données, elle permet de détecter rapidement la panne d'une route IP et de basculer le trafic sur un chemin de secours. Elle permet également de découvrir dynamiquement les chemins dans le réseau overlay qui optimisent une métrique de routage spécifique à l'application. Nous décrivons l'architecture et l'implémentation du système, ainsi que les expériences réalisées à la fois en émulation et sur une plateforme réelle composée de plusieurs centres de données situés dans différents pays. / The high variability of traffic has become one of the major problems faced by network infrastructure managers . Under these conditions, flow route optimization based solely on an average busy hour traffic matrix is no longer relevant. The work done in this thesis aims to design dynamic routing optimization methods, adapting in real time the routes used by the flows to the actual network traffic conditions.We first study the problem of OSPF weight optimization for intra-domain routing in IP networks, where the traffic is routed along shortest paths, according to links weights. We propose an online scheme to dynamically reconfigure the OSPF weights and therefore the routes used, to respond to observed traffic variations and reduce the network congestion rate. The proposed approach is based on robust estimation of flow traffic demands from SNMP measurements on links loads. Experimental results, both on simulated and real traffic data show that the network congestion rate can be significantly reduced in comparison to a static weight configuration.On the same idea, we are also interested in optimizing MPLS networks that manage the available resource utilization by assigning a specific path for each LSP. We propose an algorithm inspired by game theory to determine the LSP placement optimizing a nonlinear performance criterion. We establish the convergence of the algorithm and obtain bounds on its approximation factor for several cost functions. As the main advantage of this technique is to offer good quality solutions in extremely reduced computation times, we are studying its use for dynamic reconfiguration of the LSP placement.The last part of this thesis is devoted to the design and development of a software solution for the deployment of a self-healing and self-optimizing network overlay between different cloud platforms. The solution is designed such that no change is required for client applications. By regularly measuring the quality of Internet links between data centers, it can quickly detect an IP route failure and switch the traffic to a backup path. It also allows to dynamically discover the paths in the overlay network that optimize a routing metric specific to the application. We describe the system architecture and implementation, as well as the experiments in both emulation and real platform composed of several data centers located in different countries
70

Failure recovery techniques over an MPLS network using OPNET

Nemtur, Aamani January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Multi-Protocol Label Switching (MPLS) is an emerging technology which is the initial step for the forthcoming generation of communication. It uses Labels in order to identify the packets unlike the conventional IP Routing Mechanism which uses the routing table at each router to route the packet. MPLS uses the techniques of FRR with the help of RSVP/CR-LDP to overcome the link and/or node failures in the network. On the other hand there are certain limitations/drawbacks of using the above mechanisms for Failure Detection and Recovery which are multiple protocols such as RSVP/CR-LDP over OSPF/IS-IS and complex algorithms to generate backup paths since each router works individually in order to create a backup tunnel. So to overcome the listed limitations, this paper discusses a new technique for MPLS Networks which is Source Routing \cite{48}. Source Routing is the technique in which the source plays the role of directing the packet to the destination and no other router plays the role of routing the packet in the network. Using the OPNET Modeler 17.5 tool for implementing source routing when there is a network failure is performed and the results are compared by implementing RSVP/CR-LDP over the same failed network. The comparative results show that the network performance is best in the case of Source Routing implementation as compared to the RSVP and CR-LDP signaling over the MPLS Networks.

Page generated in 0.016 seconds