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<p>The study of Internet traffic behavior in a real IP network is the subject of this thesis. Traffic Matrix of a telecommunication network represents the exchanged traffic volume between the source and destination nodes in the network and is a critical input for network studies. However, in most cases, traffic matrices are not readily available. Existing network management protocols such as the ‘Simple Network Management Protocol’ (SNMP) have been used to gather other observable measures, such as link load observations. The first part of this thesis reviews famous methods and approaches that try to infer and estimate the source-destination traffic matrix from the observable link loads.</p> <p>Another important subject in networks is to predict bandwidth requirements in the future. The second part of this thesis reviews some existing methods and approaches of traffic prediction. Recently a traffic prediction method which uses multiple Time-Series analysis, each operating on a different time-scale, has been proposed. This method uses multiple ‘AutoRegressive Integrated Moving Average’ (ARIMA) filters to predict the future bandwidth requirements. Each ARIMA filter operates on a different time scale, i.e., quarter-hour, hour, day, and week. The proposed method associates a weight with each ARIMA filter, and adjusts the weights according to which filter is currently the most accurate predictor. A review of this newly proposed method is presented. Extensive experimental results have been gathered to test the robustness of the method. The filter coefficients of each ARIMA filter have been varied, and the accuracy of the predicted traffic has been measured. Extensive experimental measurements indicate that the model is very robust, and that large changes to each filter's coefficients have only a small effect on the accuracy. In all cases we evaluated, the method is very robust, predicting short-term future traffic demands with typically ≈95% success rates.</p> / Master of Applied Science (MASc)

Se plantea un problema de cambio de infraestructura y rediseño de red de comunicaciones en una empresa dedicada al servicio de transferencia electrónica de fondos interbancarios a través de una red de cajeros automáticos y al procesamiento y administración de tarjetas de débito y crédito. Tanto en el frente de los cajeros automáticos o terminales transaccionales, como en el frente de los computadores que autorizan las transacciones, se han ido experimentando y exigiendo cambios, los cuales no solo han involucrado nuevas tecnologías y aplicaciones, sino también la apertura a protocolos de comunicación como el TCP/IP con nuevos servicios y posibilidades, en un servicio financiero, que por mantener altos niveles de seguridad, mantenía protocolos de comunicación “heredados” como el X.25 y el SNA. En el presente documento se revisa la situación inicial de la red, los servicios y las necesidades del negocio, y la evolución de las redes de cajeros. Con el fin de conseguir los objetivos, se plantean propuestas de solución para dar soporte a las aplicaciones con protocolos “heredados” en una red IP, se revisan las alternativas técnico-económicas de enlaces de comunicación, las propuestas para la renovación de la infraestructura de comunicaciones y seguridad, y finalmente una serie de recomendaciones para la implantación y la migración a la red IP. Con un adecuado planeamiento e implantación de políticas de seguridad adecuadas, en una red privada, publica o compartida con otra institución, es posible conseguir una red de cajeros automáticos TCP/IP eficiente, segura, con alta disponibilidad, y capaz de brindar mayores servicios.

No / In this paper, the requirements for personal environments mobility are addressed from terminal and network perspectives. Practical mobility and Quality of Service (QoS) aware solutions are proposed for a heterogeneous network, comprising of satellite and terrestrial access networks connected to an IP core network. The aim, in adopting a heterogeneous environment, is to provide global, seamless service coverage to a specific area, allowing access to services independently of location. An important assumption is that nomadic user terminals attached to a particular segment should be able to exchange information with any other terminal connected to the network. This is to ensure transparency of device technology. Different communication scenarios are investigated in support of IPv4 and IPv6 operating on user platforms and over access segments. The heterogeneous network necessitates the need to perform handover between access segments to enable coverage extension and seamless connectivity. Handover procedures are analyzed, and an approach is presented that enables various operation and segment specific parameters to be taken into account when deciding upon the need to perform handover and in selecting the optimum access segment. In order to ensure transparency of network technology, the need for end-to-end QoS support is discussed, bearing in mind the deployment of both IntServ and DiffServ enabled routers in the core network. Following this, a new admission control scheme, named Gauge&Gate Reservation with Independent Probing (GRIP), is proposed. The paper concludes with a description of a laboratory testbed, which has been developed in order to verify the presented procedures, together with performance measurements of the handover and the GRIP algorithms.

No / Satellite communication with its world-wide coverage has now become an indispensable part of the Aeronautical communication. Support for high-speed Internet access by the new generation satellite systems has made the provision of IP-based multimedia applications on-board the aircraft possible at all times. Considering the expensive nature of satellite resources, IP multicast can provide a cost-effective and bandwidth saving means of delivering real-time group communication and streaming media to air passengers and crew during a flight. In IP multicast communication, traffic from the source travels along the established multicast tree to reach all group members. For mobile receivers like the aircraft which may move from one satellite beam to another, then special techniques are required to ensure that a branch of the multicast tree follows the mobile receiver into the target beam. This paper proposes a novel technique based on the Proxy Mobile IPv6 (PMIPv6) protocol to support IP multicast receiver mobility over satellite networks for an aircraft as it moves and changes its point of attachment from one satellite gateway (GW) to another. Performance evaluation shows that the proposed scheme is better than the Mobile IPv6-based approach in terms of GW handover (GWH) latency and number of packets lost during GWH.

No / New generation of satellite systems with on-board processing (switching/routing) and support for multiple spot beams will play a key role in the provision of mobile and ubiquitous Internet-based communications. To achieve this `anywhere anytime' communication in a global multi-beam satellite network with many gateways (GWs), the challenges of beam, gateway and satellite handovers faced by the satellite terminals mounted on mobile platforms such as long haul flights, global maritime vessels and continental trains must be adequately dealt with. Network-based localised mobility protocol proxy mobile IPv6 (PMIPv6) where the IP mobility procedures are relocated from the mobile nodes to the network components has been defined by the IETF for terrestrial networks. This paper proposes how the concept of PMIPv6 could be used to support IP mobility in a mesh regenerative multi-beam satellite network. What makes this proposed approach different from that defined by the IETF is the absence of tunnelling throughout the system and the difference in the roles played by the mobility agents.

IP telephony is defined as the transport of telephony calls over an IP network. IP telephony exploits the integration of voice and data networks. However, enterprises are still reluctant to deploy IP telephony despite the potential increase in productivity and reduction of costs. The principal concerns are: can IP telephony provide the same level of performance in terms of security, reliability, and scalability as traditional telephony? If so, are its proclaimed benefits such as flexibility and mobility cost-effective? The aim of this thesis is to analyze how to deploy IP telephony in large corporations - while providing the necessary security and facilitating mobility. Through the different parts of this thesis, we will analyze the applicable technologies, along with their integration and management. We will focus on the essential requirements for an enterprise of scalability, reliability, flexibility, high-availability, and cost-effectiveness. The massive changes brought about due to the deregulation of telecommunications in nearly all countries, the increasingly global nature of business, and the progressively affordable and power technology underlying information and communication technologies have lead to increasing adoption of IP telephony by residential and commercial users. This thesis will examine these technologies in the context of a very large distributed corporation. / IP telefoni är definierat som transporten av telefon samtal genom ett IP nätverk. IP telefoni utnyttjar integrationen av tal och data nätverk. Dock är affärsföretag fortfarande motsträviga till att införa IP telefoni trots potentiell ökning i produktivitet och minskade kostnader. Huvud bekymren är: kan IP telefoni tillhandahålla samma nivå av prestanda med avseende på säkerhet, tillförlitlighet, och skalbarhet som traditionell telefoni? Och i så fall, är dom proklamerade fördelarna flexibilitet och rörlighet kostnadseffektiva? Målet för detta examensarbete är att analysera hur IP telefoni kan införas i stora affärsföretag - medan samtidigt tillhandahålla nödvändig säkerhet och främja rörlighet. Genom olika delar av detta examensarbete, analyserar vi tillämpliga teknologier, inklusive deras integrering och skötsel. Vi kommer att fokusera på de grundläggande kraven för ett affärsföretag gällande skalbarhet, tillförlitlighet, flexibilitet, hög tillgänglighet, och kostnadseffektivitet. Dom massiva förändringarna frambringade i och med avregleringen av telekommunikation i stort sett alla länder, affärsverksamhetens alltmer globala natur, och de progressivt kostnadseffektiva och kraftfulla underliggande teknologier bakom informations och kommunikations system har lett till ökande adoptering av IP telefoni av både privata och kommersiella användare. Detta examensarbete undersöker relevanta teknologier i samband med mycket stora utbredda affärsföretag. / <p>Exchange student from Centro Politecnico Superior (University of Zaragoza, Spain).</p>