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Especificação, desenvolvimento e prototipagem de um protocolo de alta disponibilidade em FPGAOliveira, Rômerson Deiny 21 August 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The increasing number of users connected to the Internet led it to become a major
vehicle for personal and business transactions in the last years. Nevertheless, its unavailability
can result in losses, including nancial ones, for its users. Despite of all eorts to
keep the network availability nearest to 100% of the time, reasearches have shown that the
existing protocols have two algorithmic problems caused by message losses or disruption,
named No Brain and Split Brain, which attack the network availability and lead it
to crash. Thus, those researches propose that such protocols must be changed considering
the possibility of message loss. In this way, this research species and implements
the High Availability Router Protocol (HARP), which is a new high availability protocol
that operates in stateless environments. Furthermore, a validation system is presented
to test high availability protocols for the sake of link failures. The specication concerns
to environment assumptions, services, vocabulary, format and procedure rules specied
by nite state machine, moreover, the specication is complemented with a TLA+ formal
description regarding concurrent systems context intending to ratify the HARP good
properties. The HARP implementation consists of its prototyping on FPGA and the
validation system based on a System-on-Programmable Chip (SOPC). / O crescente número de usuários conectados à Internet favoreceu que ela se tornasse
um dos principais veículos de transações pessoais e empresariais nos últimos anos. Entretanto,
sua indisponibilidade pode acarretar perdas, inclusive de caráter nanceiro, aos
seus usuários. Apesar dos esforços empenhados para manter a rede 100% do tempo dispon
ível, pesquisas apontam que os protocolos de alta disponibilidade apresentam problemas
algorítmicos conhecidos como Acéfalo e Cérebro Partido, que são causados por perdas e
erros de mensagens e levam à indisponibilidade da rede. Tais pesquisas propõem, então,
que alterações sejam feitas nas especicações dos protocolos existentes considerando que
mensagens podem não chegar a seus destinos conforme previsto. Em virtude disso, este
trabalho especica e implementa um novo protocolo de alta disponibilidade, chamado
High Availability Router Protocol (HARP), cuja operação acontece em ambientes sem
preservação de estado. Adicionalmente, apresenta-se um sistema de validação para protocolos
de alta disponibilidade que os testam segundo falhas nos canais de comunicação. A
especicação do HARP concerne ao ambiente de operação, serviços, vocabulário, formato
de mensagens e regras de procedimento especicadas através de máquinas de estados -
nitos. Ademais, a especicação é complementada pela descrição formal em TLA+ e sua
vericação no contexto de sistemas concorrentes para raticar as boas propriedades do
protocolo. A implementação do HARP consiste da prototipagem em FPGA e o sistema
de validação é baseado em um System on a Programmable Chip. / Mestre em Ciência da Computação
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Redundance v datových sítích / Redundancy in data networksŠoun, Jan January 2010 (has links)
This thesis focuses on redundancy in data networks and on technologies which are used to achieve high availability in network infrastructure. This thesis is based on industry standards published by well-known standardization authorities. One proprietary technology which can effectively replace these standards and simplify the whole network is also presented in more detail. The theoretical part individually describes all such technologies and standards. The practical part deals with an appropriate combination of these technologies and their application in a specific product environment. This work is meant to describe the whole concept of high availability in network infrastructure and should be instrumental in understanding how these technologies are deployed in practice.
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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.
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Modelování protokolů HSRP a GLBP pro redundanci brány / Modelling HSRP and GLBP Gateway Redundancy ProtocolsHoluša, Jan January 2016 (has links)
This thesis deals with theoretical analysis of First Hop Redundancy Protocols. It describes Hot Standby Router Protocol, Virtual Router Redundancy Protocol and Gateway Load Balancing Protocol. It also shows examples of configuration of each protocol on Cisco devices with supported version of the Cisco IOS. Furthermore, this thesis includes design of two of these protocols, Hot Standby Router Protocol and Gateway Load Balancing Protocol, and their implementation in discrete event simulator OMNeT++ and Automated Network Simulation and Analysis library. Finally, the thesis presents results of testing of the implementations in comparison with actual Cisco devices.
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Fast Fault Recovery in Switched Networks for Carrying IP Telephony TrafficEisazadeh, Ali Akbar, Espahbodi, Nora January 2010 (has links)
<p>One of the most parts of VOIP management is fault management and, in having a good fault management, finding good mechanisms to detect faults in the network have to be considered.</p><p>The main focus of this project is to implement different types of fast fault recovery protocols in networks<strong>,</strong> especially networks that carry IP telephony. Having a complete understanding of some common link failure detection and fault recovery protocols<strong>,</strong> such as spanning tree protocol (STP), rapid spanning tree protocol (RSTP) and per-VLAN spanning tree protocol (PVSTP)<strong>,</strong> and also having a complete understanding of three other common techniques for fault detection and fault recovery, such as hot standby routing protocol (HSRP), virtual router redundancy protocol (VRRP) and gateway load balancing protocol (GLBP) will be regarded in the project. We are going to test some fault recovery protocols which can be used in IP telephony networks and choose the best. We intend to focus on this issue in LAN environment in theoretical descriptions and practical implementations.</p><p>The final outcome of the thesis is implementation in the Halmstad University’s lab environment to obtain the final result. For doing our thesis, we are going to use some technical tools as hardware tools (Cisco L3 and L2 switches, Routers, IP Phones) and tools which are used for network performance monitoring<strong>,</strong> like as CommVeiw.</p>
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Fast Fault Recovery in Switched Networks for Carrying IP Telephony TrafficEisazadeh, Ali Akbar, Espahbodi, Nora January 2010 (has links)
One of the most parts of VOIP management is fault management and, in having a good fault management, finding good mechanisms to detect faults in the network have to be considered. The main focus of this project is to implement different types of fast fault recovery protocols in networks, especially networks that carry IP telephony. Having a complete understanding of some common link failure detection and fault recovery protocols, such as spanning tree protocol (STP), rapid spanning tree protocol (RSTP) and per-VLAN spanning tree protocol (PVSTP), and also having a complete understanding of three other common techniques for fault detection and fault recovery, such as hot standby routing protocol (HSRP), virtual router redundancy protocol (VRRP) and gateway load balancing protocol (GLBP) will be regarded in the project. We are going to test some fault recovery protocols which can be used in IP telephony networks and choose the best. We intend to focus on this issue in LAN environment in theoretical descriptions and practical implementations. The final outcome of the thesis is implementation in the Halmstad University’s lab environment to obtain the final result. For doing our thesis, we are going to use some technical tools as hardware tools (Cisco L3 and L2 switches, Routers, IP Phones) and tools which are used for network performance monitoring, like as CommVeiw.
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