404 research outputs found
Mobile MPLS-TP - Support the mobility of terminal devices
MPLS architecture for transport networks play the significant role in the development of next generation networks, in particular with regard to the guarantee of continuity of communications "end-to-end" through a variety of heterogeneous segments of the telecommunications network. The article presents the concept of Mobile MPLS-TP with the use of OAM channels to support the mobility of users and optimize "Handoff" procedure in a hierarchical network topology
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Traffic engineering multi-layer optimization for wireless mesh network transmission a campus network routing protocol transmission performance inhancement
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityThe wireless mesh network is a potential network for the future due to its excellent inherent characteristic for dynamic self-healing, self-configuration and self-organization. It also has the advantage of easy interoperability networking and the ability to form multi-linked ad-hoc networks. It has a decentralized topology, is cheap and highly scalable. Furthermore, its ease in deployment and easy maintenance are other inherent networking qualities. These aforementioned qualities of the wireless mesh network bring advantages to transmission capability of heterogeneous networks. However, transmissions in wireless mesh network create comparative performance based challenges such as congestion, load-balancing, scalability over increasing networks and coverage capacity. Consequently, these challenges and problems in the routing and switching of packets in the wireless mesh network routing protocols led to a proposal on the resolution of these failures with a combination algorithm and a management based security for the network and its transmitted packets. There are equally contentious services like reliability of the network and quality of service for real-time multimedia traffic flows with other challenges such as path computation and selection in the wireless mesh network.
This thesis is therefore a cumulative proposal to the resolution of the outlined challenges and open research areas posed by using wireless mesh network routing protocol. It advances the resolution of these challenges in the mesh environment using a hybrid optimization â traffic engineering, to increase the effectiveness and the reliability of the network. It also proffers a cumulative resolution of the diverse contributions on wireless mesh network routing protocol and transmission. Adaptation and optimization are carried out on the wireless mesh network designed network using traffic engineering mechanism and technique. The research examines the patterns of mesh packet transmission and evaluates the challenges and failures in the mesh network packet transmission. It develops a solution based algorithm for resolutions and proposes the traffic engineering based solution.. These resultant performances and analysis are usually tested and compared over wireless mesh IEEE802.11n or other older proposed documented solution.
This thesis used a carefully designed campus mesh network to show a comparative evaluation of an optimal performance of the mesh nodes and routers over a normal IEE802.11n based wireless domain network to show differentiation by optimization using the created algorithms. Furthermore, the indexes of performance being the metric are used to measure the utility and the reliability, including capacity and throughput at the destination during traffic engineered transmission. In addition, the security of these transmitted data and packets are optimized under a traffic engineered technique. Finally, this thesis offers an understanding to the security contribution using traffic engineering resolution to create a management algorithm for processing and computation of the wireless mesh networks security needs. The results of this thesis confirmed, completed and extended the existing predictions with real measurement
Experimental evaluation of SDN-based service provisioning in mobile networks
5G networks will be characterized by their diversity in terms of traffic patterns, multi-tenancy and heterogeneous and stringent traffic requirements. Network softwarization is a key enabler to cope with such management burden, as it provides the ability to control all networking functions through (re)programming, thus providing higher flexibility to meet heterogeneous requirements while keeping deployment and operational costs low. In this article, we aim at experimentally validating how Software Defined Networking (SDN) concepts can greatly simplify network operation in future 5G operator networks. This simplification is achieved by allowing to very easily create and modify network services and thus customize network operation based on the operatorâs requirements. The main contribution of this article is to present a prototype of an SDN-based architecture in a real-life test-bed, where we evaluate the associated implementation costs and we confirm through experimentation that novel complex services can be created with relatively low effort.The research leading to these results has been partially performed within the framework of the H2020-ICT-2014-2 projects 5G NORMA and 5G-Crosshaul, and spanish DRONEXT project
Hybrid SDN Evolution: A Comprehensive Survey of the State-of-the-Art
Software-Defined Networking (SDN) is an evolutionary networking paradigm
which has been adopted by large network and cloud providers, among which are
Tech Giants. However, embracing a new and futuristic paradigm as an alternative
to well-established and mature legacy networking paradigm requires a lot of
time along with considerable financial resources and technical expertise.
Consequently, many enterprises can not afford it. A compromise solution then is
a hybrid networking environment (a.k.a. Hybrid SDN (hSDN)) in which SDN
functionalities are leveraged while existing traditional network
infrastructures are acknowledged. Recently, hSDN has been seen as a viable
networking solution for a diverse range of businesses and organizations.
Accordingly, the body of literature on hSDN research has improved remarkably.
On this account, we present this paper as a comprehensive state-of-the-art
survey which expands upon hSDN from many different perspectives
Dynamic bandwidth allocation in multi-class IP networks using utility functions.
PhDAbstact not availableFujitsu Telecommunications Europe Lt
Congestion control mechanisms within MPLS networks
PhDAbstract not availabl
Esquema de controlo para redes multicast baseadas com classes
Doutoramento em Engenharia ElectrotécnicaThe expectations of citizens from the Information Technologies (ITs) are increasing as the ITs have become integral part of our society, serving all kinds of activities whether professional, leisure, safety-critical applications or business. Hence, the limitations of the traditional network designs to provide innovative and enhanced services and applications motivated a consensus to integrate all services over packet switching infrastructures, using the Internet Protocol, so as to leverage flexible control and economical benefits in the Next Generation Networks (NGNs). However, the Internet is not capable of treating services differently while each service has its own requirements (e.g., Quality of Service - QoS). Therefore, the need for more evolved forms of communications has driven to radical changes of architectural and layering designs which demand appropriate solutions for service admission and network resources control. This Thesis addresses QoS and network control issues, aiming to improve overall control performance in current and future networks which classify services into classes. The Thesis is divided into three parts.
In the first part, we propose two resource over-reservation algorithms, a Class-based bandwidth Over-Reservation (COR) and an Enhanced COR (ECOR). The over-reservation means reserving more bandwidth than a Class of Service (CoS) needs, so the QoS reservation signalling rate is reduced. COR and ECOR allow for dynamically defining over-reservation parameters for CoSs based on network interfaces resource conditions; they aim to reduce QoS signalling and related overhead without incurring CoS starvation or waste of bandwidth. ECOR differs from COR by allowing for optimizing control overhead minimization. Further, we propose a centralized control mechanism called Advanced Centralization Architecture (ACA), that uses a single state-full Control Decision Point (CDP) which maintains a good view of its underlying network topology and the related links resource statistics on real-time basis to control the overall network. It is very important to mention that, in this Thesis, we use multicast trees as the basis for session transport, not only for group communication purposes, but mainly to pin packets of a session mapped to a tree to follow the desired tree. Our simulation results prove a drastic reduction of QoS control signalling and the related overhead without QoS violation or waste of resources. Besides, we provide a generic-purpose analytical model to assess the impact of various parameters (e.g., link capacity, session dynamics, etc.) that generally challenge resource overprovisioning control.
In the second part of this Thesis, we propose a decentralization control mechanism called Advanced Class-based resource OverpRovisioning (ACOR), that aims to achieve better scalability than the ACA approach. ACOR enables multiple CDPs, distributed at network edge, to cooperate and exchange appropriate control data (e.g., trees and bandwidth usage information) such that each CDP is able to maintain a good knowledge of the network topology and the related links resource statistics on real-time basis. From scalability perspective, ACOR cooperation is selective, meaning that control information is exchanged dynamically among only the CDPs which are concerned (correlated).
Moreover, the synchronization is carried out through our proposed concept of Virtual Over-Provisioned Resource (VOPR), which is a share of over-reservations of each interface to each tree that uses the interface. Thus, each CDP can process several session requests over a tree without requiring synchronization between the correlated CDPs as long as the VOPR of the tree is not exhausted. Analytical and simulation results demonstrate that aggregate over-reservation control in decentralized scenarios keep low signalling without QoS violations or waste of resources. We also introduced a control signalling protocol called ACOR Protocol (ACOR-P) to support the centralization and decentralization designs in this Thesis. Further, we propose an Extended ACOR (E-ACOR) which aggregates the VOPR of all trees that originate at the same CDP, and more session requests can be processed without synchronization when compared with ACOR. In addition, E-ACOR introduces a mechanism to efficiently track network congestion information to prevent unnecessary synchronization during congestion time when VOPRs would exhaust upon every session request. The performance evaluation through analytical and simulation results proves the superiority of E-ACOR in minimizing overall control signalling overhead while keeping all advantages of ACOR, that is, without incurring QoS violations or waste of resources.
The last part of this Thesis includes the Survivable ACOR (SACOR) proposal to support stable operations of the QoS and network control mechanisms in case of failures and recoveries (e.g., of links and nodes). The performance results show flexible survivability characterized by fast convergence time and differentiation of traffic re-routing under efficient resource utilization i.e. without wasting bandwidth.
In summary, the QoS and architectural control mechanisms proposed in this Thesis provide efficient and scalable support for network control key sub-systems (e.g., QoS and resource control, traffic engineering, multicasting, etc.), and thus allow for optimizing network overall control performance.Ă medida que as Tecnologias de Informação (TIs) se tornaram parte integrante da nossa sociedade, a expectativa dos cidadĂŁos relativamente ao uso desses serviços tambĂ©m demonstrou um aumento, seja no Ăąmbito das atividades profissionais, de lazer, aplicaçÔes de segurança crĂtica ou negĂłcios. Portanto, as limitaçÔes dos projetos de rede tradicionais quanto ao fornecimento de serviços inovadores e aplicaçÔes avançadas motivaram um consenso quanto Ă integração de todos os serviços e infra-estruturas de comutação de pacotes, utilizando o IP, de modo a extrair benefĂcios econĂłmicos e um controlo mais flexĂvel nas Redes de Nova Geração (RNG). Entretanto, tendo em vista que a Internet nĂŁo apresenta capacidade de diferenciação de serviços, e sabendo que cada serviço apresenta as suas necessidades prĂłprias, como por exemplo, a Qualidade de Serviço - QoS, a necessidade de formas mais evoluĂdas de comunicação tem-se tornado cada vez mais visĂvel, levando a mudanças radicais na arquitectura das redes, que exigem soluçÔes adequadas para a admissĂŁo de serviços e controlo de recursos de rede. Sendo assim, este trabalho aborda questĂ”es de controlo de QoS e rede com o objetivo de melhorar o desempenho do controlo de recursos total em redes atuais e futuras, atravĂ©s da anĂĄlise dos serviços de acordo com as suas classes de serviço. Esta Tese encontra-se dividida em trĂȘs partes.
Na primeira parte sĂŁo propostos dois algoritmos de sobre-reserva, o Class-based bandwidth Over-Reservation (COR) e uma extensĂŁo melhorada do COR denominado de Enhanced COR (ECOR). A sobre-reserva significa a reserva de uma largura de banda maior para o serviço em questĂŁo do que uma classe de serviço (CoS) necessita e, portanto, a quantidade de sinalização para reserva de recursos Ă© reduzida. COR e ECOR consideram uma definição dinĂąmica de sobre-reserva de parĂąmetros para CoSs com base nas condiçÔes da rede, com vista Ă redução da sobrecarga de sinalização em QoS sem que ocorra desperdĂcio de largura de banda. O ECOR, por sua vez, difere do COR por permitir a otimização com minimização de controlo de overhead. AlĂ©m disso, nesta Tese Ă© proposto tambĂ©m um mecanismo de controlo centralizado chamado Advanced Centralization Architecture (ACA) , usando um Ășnico Ponto de Controlo de DecisĂŁo (CDP) que mantĂ©m uma visĂŁo ampla da topologia de rede e de anĂĄlise dos recursos ocupados em tempo real como base de controlo para a rede global. Nesta Tese sĂŁo utilizadas ĂĄrvores multicast como base para o transporte de sessĂŁo, nĂŁo sĂł para fins de comunicação em grupo, mas principalmente para que os pacotes que pertençam a uma sessĂŁo que Ă© mapeada numa determinada ĂĄrvore sigam o seu caminho.
Os resultados obtidos nas simulaçÔes dos mecanismos mostram uma redução significativa da sobrecarga da sinalização de controlo, sem a violação dos requisitos de QoS ou desperdĂcio de recursos. AlĂ©m disso, foi proposto um modelo analĂtico no sentido de avaliar o impacto provocado por diversos parĂąmetros (como por exemplo, a capacidade da ligação, a dinĂąmica das sessĂ”es, etc), no sobre-provisionamento dos recursos.
Na segunda parte desta tese propĂŽe-se um mecanismo para controlo descentralizado de recursos denominado de Advanced Class-based resource OverprRovisioning (ACOR), que permite obter uma melhor escalabilidade do que o obtido pelo ACA. O ACOR permite que os pontos de decisĂŁo e controlo da rede, os CDPs, sejam distribuĂdos na periferia da rede, cooperem entre si, atravĂ©s da troca de dados e controlo adequados (por exemplo, localização das ĂĄrvores e informaçÔes sobre o uso da largura de banda), de tal forma que cada CDP seja capaz de manter um bom conhecimento da topologia da rede, bem como das suas ligaçÔes. Do ponto de vista de escalabilidade, a cooperação do ACOR Ă© seletiva, o que significa que as informaçÔes de controlo sĂŁo trocadas de forma dinĂąmica apenas entre os CDPs analisados. AlĂ©m disso, a sincronização Ă© feita atravĂ©s do conceito proposto de Recursos Virtuais Sobre-Provisionado (VOPR), que partilha as reservas de cada interface para cada ĂĄrvore que usa a interface. Assim, cada CDP pode processar pedidos de sessĂŁo numa ou mais ĂĄrvores, sem a necessidade de sincronização entre os CDPs correlacionados, enquanto o VOPR da ĂĄrvore nĂŁo estiver esgotado. Os resultados analĂticos e de simulação demonstram que o controlo de sobre-reserva Ă© agregado em cenĂĄrios descentralizados, mantendo a sinalização de QoS baixa sem perda de largura de banda. TambĂ©m Ă© desenvolvido um protocolo de controlo de sinalização chamado ACOR Protocol (ACOR-P) para suportar as arquitecturas de centralização e descentralização deste trabalho. O ACOR Estendido (E-ACOR) agrega a VOPR de todas as ĂĄrvores que se originam no mesmo CDP, e mais pedidos de sessĂŁo podem ser processados sem a necessidade de sincronização quando comparado com ACOR. AlĂ©m disso, E-ACOR introduz um mecanismo para controlar as informaçÔes Ă cerca do congestionamento da rede, e impede a sincronização desnecessĂĄria durante o tempo de congestionamento quando os VOPRs esgotam consoante cada pedido de sessĂŁo. A avaliação de desempenho, atravĂ©s de resultados analĂticos e de simulação, mostra a superioridade do E-ACOR em minimizar o controlo geral da carga da sinalização, mantendo todas as vantagens do ACOR, sem apresentar violaçÔes de QoS ou desperdĂcio de recursos.
A Ășltima parte desta Tese inclui a proposta para recuperação a falhas, o Survivability ACOR (SACOR), o qual permite ter QoS estĂĄvel em caso de falhas de ligaçÔes e nĂłs. Os resultados de desempenho analisados mostram uma capacidade flexĂvel de sobrevivĂȘncia caracterizada por um tempo de convergĂȘncia rĂĄpido e diferenciação de trĂĄfego com uma utilização eficiente dos recursos.
Em resumo, os mecanismos de controlo de recursos propostos nesta Tese fornecem um suporte eficiente e escalĂĄvel para controlo da rede, como tambĂ©m para os seus principais sub-sistemas (por exemplo, QoS, controlo de recursos, engenharia de trĂĄfego, multicast, etc) e, assim, permitir a otimização do desempenho da rede a nĂvel do controlo global
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