2,203 research outputs found

    Service-Oriented Multigranular Optical Network Architecture for Clouds

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    This paper presents a novel service-oriented network architecture to bridge the informational gap between user applications and optical networks providing technology-agnostic multigranular optical network services for clouds. A mediation layer (service plane) between user applications and network control is proposed to facilitate a mapping process between user application requests and the network services. At the network level, a multigranular optical network (MGON) is proposed and implemented to support dynamic wavelength and subwavelength granularities with different transport formats [optical burst switched (OBS), optical burst transport (OBT)], reservation protocols (one-way, two-way), and different quality-of-service (QoS) levels per service type. The service-oriented multigranular optical network has been designed, implemented, and demonstrated on an experimental testbed. The testbed consists of service and network resource provisioning, service abstraction, and network resource virtualization. The service-to-network interoperation is provided by means of a gateway that maps service requests to technology-specific parameters and a common signaling channel for both service and network resource provisioning

    Scalable Impairment-Aware Anycast Routing in Multi-Domain Optical Grid Networks

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    ABSTRACT In optical Grid networks, the main challenge is to account for not only network parameters, but also for resource availability. Anycast routing has previously been proposed as an effective solution to provide job scheduling services in optical Grids, offering a generic interface to access Grid resources and services. The main weakness of this approach is its limited scalability, especially in a multi-domain scenario. This paper proposes a novel anycast proxy architecture, which extends the anycast principle to a multi-domain scenario. The main purpose of the architecture is to perform aggregation of resource and network states, and as such improve computational scalability and reduce control plane traffic. Furthermore, the architecture has the desirable properties of allowing Grid domains to maintain their autonomy and hide internal configuration details from other domains. Finally, we propose an impairment-aware anycast routing algorithm that incorporates the main physical layer characteristics of large-scale optical networks into its path computation process. By integrating the proposed routing scheme into the introduced architecture we demonstrate significant network performance improvements. Keywords: Grid computing, routing algorithms, optical networks, physical impairments, anycast routing. INTRODUCTION Today, the need for network systems to support storage and computing services for science and business, is often satisfied by relatively isolated computing infrastructure (clusters). Migration to truly distributed and integrated applications requires optimization and (re)design of the underlying network technology to create a Grid platform for the cost and resource efficient delivery of network services with substantial data transfer, processing power and/or data storage requirements. Optical networks offer an undeniable potential for the Grid, given their proven track-record in the context of high-speed, long-haul, networking. Not only eScience applications dealing with large experimental data sets (e.g. particle physics) but also business/consumer oriented applications can benefit from optical Grid infrastructure [1]: both the high data rates typical of eScience applications and the low latency requirements of consumer/business applications (cf. interactivity) can effectively be addressed. When using transparent WDM as such network technology, signals are transported end-to-end optically without being converted to the electrical domain in between. Connection provisioning of all-optical connections (lightpaths) between source and destination nodes is based on specific routing and wavelength assignment algorithms (RWA). Traditional RWA schemes only account for network conditions such as connectivity and available capacity, without considering physical layer details. However, in transparent optical networks covering large geographical areas, the optical signal experiences the accumulation of physical impairments through transmission and switching, possibly resulting in unacceptable signal quality Another emerging and challenging task in distributed and heterogeneous computing environments, is job scheduling: when and where to execute a given Grid job, based on the requirements of the job (for instance a deadline and minimal computational power) and the current state of the network and resources. Traditionally, a local scheduler optimizes utilization and performance of a single Grid site, while a meta-scheduler is distributes workload across different sites. Current implementations of these (meta-)schedulers only account for Grid resource availability In this paper we propose a novel architecture to support impairment-aware anycast routing for large-scale optical Grid networks. Section 2 discusses general approaches to support multi-domain networks. We then proceed to introduce a novel architecture, which can provide anycast Grid services in a multi-domain scenario (Section 3). Simulation analysis is used to demonstrate the improved scalability without incurring significant performance loss. Furthermore, Section 4 shows how to incorporate physical layer impairments, to further improve the performance of optical Grid networks. Conclusions are presented in Section 5

    Towards a cloud enabler : from an optical network resource provisioning system to a generalized architecture for dynamic infrastructure services provisioning

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    This work was developed during a period where most of the optical management and provisioning system where manual and proprietary. This work contributed to the evolution of the state of the art of optical networks with new architectures and advanced virtual infrastructure services. The evolution of optical networks, and internet globally, have been very promising during the last decade. The impact of mobile technology, grid, cloud computing, HDTV, augmented reality and big data, among many others, have driven the evolution of optical networks towards current service technologies, mostly based on SDN (Software Defined Networking) architectures and NFV(Network Functions Virtualisation). Moreover, the convergence of IP/Optical networks and IT services, and the evolution of the internet and optical infrastructures, have generated novel service orchestrators and open source frameworks. In fact, technology has evolved that fast that none could foresee how important Internet is for our current lives. Said in other words, technology was forced to evolve in a way that network architectures became much more transparent, dynamic and flexible to the end users (applications, user interfaces or simple APIs). This Thesis exposes the work done on defining new architectures for Service Oriented Networks and the contribution to the state of the art. The research work is divided into three topics. It describes the evolution from a Network Resource Provisioning System to an advanced Service Plane, and ends with a new architecture that virtualized the optical infrastructure in order to provide coordinated, on-demand and dynamic services between the application and the network infrastructure layer, becoming an enabler for the new generation of cloud network infrastructures. The work done on defining a Network Resource Provisioning System established the first bases for future work on network infrastructure virtualization. The UCLP (User Light Path Provisioning) technology was the first attempt for Customer Empowered Networks and Articulated Private Networks. It empowered the users and brought virtualization and partitioning functionalities into the optical data plane, with new interfaces for dynamic service provisioning. The work done within the development of a new Service Plane allowed the provisioning of on-demand connectivity services from the application, and in a multi-domain and multi-technology scenario based on a virtual network infrastructure composed of resources from different infrastructure providers. This Service Plane facilitated the deployment of applications consuming large amounts of data under deterministic conditions, so allowing the networks behave as a Grid-class resource. It became the first on-demand provisioning system that at lower levels allowed the creation of one virtual domain composed from resources of different providers. The last research topic presents an architecture that consolidated the work done in virtualisation while enhancing the capabilities to upper layers, so fully integrating the optical network infrastructure into the cloud environment, and so providing an architecture that enabled cloud services by integrating the request of optical network and IT infrastructure services together at the same level. It set up a new trend into the research community and evolved towards the technology we use today based on SDN and NFV. Summing up, the work presented is focused on the provisioning of virtual infrastructures from the architectural point of view of optical networks and IT infrastructures, together with the design and definition of novel service layers. It means, architectures that enabled the creation of virtual infrastructures composed of optical networks and IT resources, isolated and provisioned on-demand and in advance with infrastructure re-planning functionalities, and a new set of interfaces to open up those services to applications or third parties.Aquesta tesi es va desenvolupar durant un període on la majoria de sistemes de gestió de xarxa òptica eren manuals i basats en sistemes propietaris. En aquest sentit, la feina presentada va contribuir a l'evolució de l'estat de l'art de les xarxes òptiques tant a nivell d’arquitectures com de provisió d’infraestructures virtuals. L'evolució de les xarxes òptiques, i d'Internet a nivell mundial, han estat molt prometedores durant l'última dècada. L'impacte de la tecnologia mòbil, la computació al núvol, la televisió d'alta definició, la realitat augmentada i el big data, entre molts altres, han impulsat l'evolució cap a xarxes d’altes prestacions amb nous serveis basats en SDN (Software Defined Networking) i NFV (Funcions de xarxa La virtualització). D'altra banda, la convergència de xarxes òptiques i els serveis IT, junt amb l'evolució d'Internet i de les infraestructures òptiques, han generat nous orquestradors de serveis i frameworks basats en codi obert. La tecnologia ha evolucionat a una velocitat on ningú podria haver predit la importància que Internet està tenint en el nostre dia a dia. Dit en altres paraules, la tecnologia es va veure obligada a evolucionar d'una manera on les arquitectures de xarxa es fessin més transparent, dinàmiques i flexibles vers als usuaris finals (aplicacions, interfícies d'usuari o APIs simples). Aquesta Tesi presenta noves arquitectures de xarxa òptica orientades a serveis. El treball de recerca es divideix en tres temes. Es presenta un sistema de virtualització i aprovisionament de recursos de xarxa i la seva evolució a un pla de servei avançat, per acabar presentant el disseny d’una nova arquitectura capaç de virtualitzar la infraestructura òptica i IT i proporcionar serveis de forma coordinada, i sota demanda, entre l'aplicació i la capa d'infraestructura de xarxa òptica. Tot esdevenint un facilitador per a la nova generació d'infraestructures de xarxa en el núvol. El treball realitzat en la definició del sistema de virtualització de recursos va establir les primeres bases sobre la virtualització de la infraestructura de xarxa òptica en el marc de les “Customer Empowered Networks” i “Articulated Private Networks”. Amb l’objectiu de virtualitzar el pla de dades òptic, i oferir noves interfícies per a la provisió de serveis dinàmics de xarxa. En quant al pla de serveis presentat, aquest va facilitat la provisió de serveis de connectivitat sota demanda per part de l'aplicació, tant en entorns multi-domini, com en entorns amb múltiples tecnologies. Aquest pla de servei, anomenat Harmony, va facilitar el desplegament de noves aplicacions que consumien grans quantitats de dades en condicions deterministes. En aquest sentit, va permetre que les xarxes es comportessin com un recurs Grid, i per tant, va esdevenir el primer sistema d'aprovisionament sota demanda que permetia la creació de dominis virtuals de xarxa composts a partir de recursos de diferents proveïdors. Finalment, es presenta l’evolució d’un pla de servei cap una arquitectura global que consolida el treball realitzat a nivell de convergència d’infraestructures (òptica + IT) i millora les capacitats de les capes superiors. Aquesta arquitectura va facilitar la plena integració de la infraestructura de xarxa òptica a l'entorn del núvol. En aquest sentit, aquest resultats van evolucionar cap a les tendències actuals de SDN i NFV. En resum, el treball presentat es centra en la provisió d'infraestructures virtuals des del punt de vista d’arquitectures de xarxa òptiques i les infraestructures IT, juntament amb el disseny i definició de nous serveis de xarxa avançats, tal i com ho va ser el servei de re-planificació dinàmicaPostprint (published version

    Feasibility, Architecture and Cost Considerations of Using TVWS for Rural Internet Access in 5G

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    The cellular technology is mostly an urban technology that has been unable to serve rural areas well. This is because the traditional cellular models are not economical for areas with low user density and lesser revenues. In 5G cellular networks, the coverage dilemma is likely to remain the same, thus widening the rural-urban digital divide further. It is about time to identify the root cause that has hindered the rural technology growth and analyse the possible options in 5G architecture to address this issue. We advocate that it can only be accomplished in two phases by sequentially addressing economic viability followed by performance progression. We deliberate how various works in literature focus on the later stage of this ‘two-phase’ problem and are not feasible to implement in the first place. We propose the concept of TV band white space (TVWS) dovetailed with 5G infrastructure for rural coverage and show that it can yield cost-effectiveness from a service provider’s perspective

    A survey on OFDM-based elastic core optical networking

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    Orthogonal frequency-division multiplexing (OFDM) is a modulation technology that has been widely adopted in many new and emerging broadband wireless and wireline communication systems. Due to its capability to transmit a high-speed data stream using multiple spectral-overlapped lower-speed subcarriers, OFDM technology offers superior advantages of high spectrum efficiency, robustness against inter-carrier and inter-symbol interference, adaptability to server channel conditions, etc. In recent years, there have been intensive studies on optical OFDM (O-OFDM) transmission technologies, and it is considered a promising technology for future ultra-high-speed optical transmission. Based on O-OFDM technology, a novel elastic optical network architecture with immense flexibility and scalability in spectrum allocation and data rate accommodation could be built to support diverse services and the rapid growth of Internet traffic in the future. In this paper, we present a comprehensive survey on OFDM-based elastic optical network technologies, including basic principles of OFDM, O-OFDM technologies, the architectures of OFDM-based elastic core optical networks, and related key enabling technologies. The main advantages and issues of OFDM-based elastic core optical networks that are under research are also discussed

    A distributed topology information system for optical networks based on the semantic web

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    The research networking community has embraced novel network architectures to provide e-Science applications with dedicated connections instead of shared links. IP and optical services converge in these new infrastructures to form hybrid networks. Lightpaths are the services offered to clients in the optical portion of the network. They are chosen because they guarantee the appropriate QoS in terms of bandwidth and latency. NDL-the Network Description Language-is a data model offering users and providers of lightpaths with a common ontology to describe topology information of hybrid optical networks. The strength of NDL is that it supports a wide range of applications, including pathfinding, visualisation and asset management, via the definition of a common data model to exchange network descriptions. Since NDL is based on the Semantic Web techniques, it is straightforward to relate NDL with application-specific ontologies. In this paper we present the current status of the NDL schemas and its use in several applications
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