145 research outputs found
Propuesta De Diseño De Red De Datos Para La Empresa Bata En El Distrito De Miraflores
El proyecto tiene como objetivo diseñar un “Modelo de Red de Datos” como apoyo a las dependencias administrativas de la Empresa BATA, y la necesidad de aplicar políticas de seguridad y administración a todos los usuarios de la red LAN, lo cual resulta una tarea compleja en la tecnología actual pero se puede resolver aplicando diversas tecnologías y equipos de red ideales para el diseño que se quiere lograr, el presente modelo de red se propone para cumplir con los requerimientos de la Empresa en cuanto a Costo y Fidelidad. En la actualidad la necesidad de las empresas de contar con un diseño de Red confiable, seguro y eficiente para la transmisión de datos es un tema de mucha importancia debido a que las empresas requieren la interconectividad de todos sus dispositivos de red dentro de un determinado lugar y también al exterior a través de Internet, teniendo más facilidades y beneficios para la empresa. La estructura que hemos seguido en este proyecto se compone de 3 capítulos. El Primer Capítulo comprende el Planteamiento del Problema, el Segundo Capítulo el Desarrollo del marco teórico y el tercer capítulo corresponde al desarrollo del Proyecto.Trabajo de suficiencia profesiona
Application of overlay techniques to network monitoring
Measurement and monitoring are important for correct and efficient operation of a network, since these activities provide reliable information and accurate analysis for characterizing and troubleshooting a network’s performance. The focus of network measurement is to measure the volume and types of traffic on a particular network and to record the raw measurement results. The focus of network monitoring is to initiate measurement tasks, collect raw measurement results, and report aggregated outcomes.
Network systems are continuously evolving: besides incremental change to accommodate new devices, more drastic changes occur to accommodate new applications, such as overlay-based content delivery networks. As a consequence, a network can experience significant increases in size and significant levels of long-range, coordinated, distributed activity; furthermore, heterogeneous network technologies, services and applications coexist and interact. Reliance upon traditional, point-to-point, ad hoc measurements to manage such networks is becoming increasingly tenuous. In particular, correlated, simultaneous 1-way measurements are needed, as is the ability to access measurement information stored throughout the network of interest.
To address these new challenges, this dissertation proposes OverMon, a new paradigm for edge-to-edge network monitoring systems through the application of overlay techniques. Of particular interest, the problem of significant network overheads caused by normal overlay network techniques has been addressed by constructing overlay networks with topology awareness - the network topology information is derived from interior gateway protocol (IGP) traffic, i.e. OSPF traffic, thus eliminating all overlay maintenance network overhead.
Through a prototype that uses overlays to initiate measurement tasks and to retrieve measurement results, systematic evaluation has been conducted to demonstrate the feasibility and functionality of OverMon. The measurement results show that OverMon achieves good performance in scalability, flexibility and extensibility, which are important in addressing the new challenges arising from network system evolution. This work, therefore, contributes an innovative approach of applying overly techniques to solve realistic network monitoring problems, and provides valuable first hand experience in building and evaluating such a distributed system
Development of advanced multimedia services in P2P architectures
La transmissió de fluxos multimèdia en temps real (streaming) s’ha convertit en
un tema punter i de gran interès al món de la recerca d’Internet, especialment
quan ens referim a aplicacions de transmissió d’àudio i vídeo en directe a
través de xarxes peer-to-peer (P2P). Generalment, aquestes aplicacions han
de fer front a molts problemes en el seu disseny i implementació deguts a la
dinamicitat i heterogeneïtat que per natura caracteritzen les xarxes P2P. En
aquest projecte, s’introdueixen noves característiques que les aplicacions de
transmissió multimèdia P2P actuals no contemplen.
Els requisits de connexió i maquinari són diferents per a la transmissió de
fluxos de baixa i alta capacitat, no obstant, tots els nodes s’acostumen a
considerar idèntics, cosa que no representa una aproximació gaire encertada
tenint en compte un medi tan heterogeni. A més a més, amb la finalitat
d’aconseguir distinció entre nodes, es fa necessari la introducció d’un
mecanisme que permeti l’intercanvi de les capacitats específiques de cada
node, incloent-hi les de transcodificació de fluxos. Un altre aspecte a destacar
és el fet que aquestes aplicacions són difícils d’ampliar, incorporar nous
serveis o modificar les dades que porten precarregades com ara la llista de
canals de televisió disponibles, cosa que impossibilita garantir la disponibilitat
de la font tot el temps. Per altra banda, els serveis interactius tampoc s’han
desenvolupat gaire.
Aquest projecte proposa el disseny i implementació d’una plataforma de difusió
multimèdia P2P cooperativa i interactiva que permet superar els problemes
esmentats. La plataforma integra diferents mecanismes que permeten la
distribució en temps real de continguts multimèdia en diferents qualitats
incloent fluxos d’alta capacitat (com per exemple HD). Aquesta plataforma és
una solució novedosa basada en JXTA, DONET i ALM (Arbres Multicast a
nivell d’Aplicació) que proporciona un sistema ampliable segons noves
necessitats i facilita la inserció de nous serveis de valor afegit. La plataforma
proposada es fonamenta en la creació d’una arquitectura de 2 capes lògiques
superposades: una capa lògica JXTA, encarregada bàsicament de la
senyalització i intercanvi de metadades, i una capa de transmissió basada en
sockets UDP unicast. D’aquesta manera, la diferència entre la capa de
transmissió i la capa física es pot veure reduïda a partir de la informació
obtinguda de la capa JXTA, la qual es va actualitzant al llarg del temps
SFE2000/SFE2000P Fast Ethernet Switch Reference Guide
SFE2000/SFE2000P Fast Ethernet Switch Reference GuideSFE2000/SFE2000P Fast Ethernet Switch Reference Guid
Modelling PIM-SM in OMNeT++
Ve své diplomové práci se zabývám modelováním a simulací multicastového směrovacího protokolu PIM Sparse Mode v nástroji OMNeT++. Čtenář se seznámí se základními informacemi o multicastu, s protokolem PIM-SM, jeho konfigurací na zařízeních Cisco. Zároveň bude uveden do problematiky vizualizace multicastových toků v síti. Práce je zaměřena zejména na návrh a implementaci protokolu PIM-SM v OMNeT++ a rozšíření knihovny ANSAINET o další multicastový směrovací protokol.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.
Validation of "triple-play" services in the access node
Mestrado em Engenharia Electrónica e TelecomunicaçõesCom o grande crescimento das comunicações fixas, as tecnologias de
fornecimento de acesso à Internet, como o cabo (CATV) e o par de cobre
(xDSL), têm possibilitado o fornecimento de serviços adicionais para além do
típico acesso à Internet de Banda Larga (em que, desde há vários anos o
serviço de televisão já existe na tecnologia de cabo). Assim sendo, e ainda
devido a uma forte concorrência entre operadores de cabo e de “cobre”, o DSL
Forum apresenta uma solução de arquitectura da rede de acesso e agregação
que permite a migração da tradicional tecnologia ATM para Ethernet, em
tecnologias baseadas em xDSL.
A migração da arquitectura para uma rede baseada em Ethernet permite o
fornecimento de serviços adicionais que exijam altos débitos, qualidade de
serviço, transmissão de multicast, VOIP, entre outros.
A presente tese apresenta os requisitos propostos pelo DSL Forum para o
equipamento da rede de acesso e agregação: o nó de acesso (DSLAM), e um
conjunto de testes conducentes à validação dos mesmos em laboratório,
simulando uma possível rede de fornecedor de serviços.
ABSTRACT: With the large growth of fixed communications, the technology that provides
Internet access, such as cable (CATV) and copper (xDSL), need to enable the
provision of additional services beyond the typical broadband Internet access
(where, television service already exists for several years over cable
technology). Thus, because of strong competition between cable and copper
operators , DSL Forum presents an architecture and aggregation solution for
the xDSL based access networks that allows the migration of traditional ATM
technology to Ethernet.
The migration of the architecture to Ethernet based network is due to the high
speeds offer, and the possibility of additional services supporting quality of
service, multicast transmission, VOIP, amongst others.
This thesis presents the requirements proposed by the DSL Forum for the
equipment of the access network and aggregation: access node (DSLAM), and
their validation in a laboratory environment, simulating service provision
scenarios
Supporting distributed computation over wide area gigabit networks
The advent of high bandwidth fibre optic links that may be used over very large distances
has lead to much research and development in the field of wide area gigabit networking. One
problem that needs to be addressed is how loosely coupled distributed systems may be built over
these links, allowing many computers worldwide to take part in complex calculations in order
to solve "Grand Challenge" problems. The research conducted as part of this PhD has looked
at the practicality of implementing a communication mechanism proposed by Craig Partridge
called Late-binding Remote Procedure Calls (LbRPC).
LbRPC is intended to export both code and data over the network to remote machines for
evaluation, as opposed to traditional RPC mechanisms that only send parameters to pre-existing
remote procedures. The ability to send code as well as data means that LbRPC requests can
overcome one of the biggest problems in Wide Area Distributed Computer Systems (WADCS):
the fixed latency due to the speed of light. As machines get faster, the fixed multi-millisecond
round trip delay equates to ever increasing numbers of CPU cycles. For a WADCS to be
efficient, programs should minimise the number of network transits they incur. By allowing the
application programmer to export arbitrary code to the remote machine, this may be achieved.
This research has looked at the feasibility of supporting secure exportation of arbitrary
code and data in heterogeneous, loosely coupled, distributed computing environments. It has
investigated techniques for making placement decisions for the code in cases where there are a
large number of widely dispersed remote servers that could be used. The latter has resulted in
the development of a novel prototype LbRPC using multicast IP for implicit placement and a
sequenced, multi-packet saturation multicast transport protocol. These prototypes show that
it is possible to export code and data to multiple remote hosts, thereby removing the need to
perform complex and error prone explicit process placement decisions
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