The GEYSERS optical testbed: a platform for the integration, validation and demonstration of cloud-based infrastructure services

The recent evolution of cloud services is leading to a new service transformation paradigm to accommodate network infrastructures in a cost-scalable way. In this transformation, the network constitutes the key to efficiently connect users to services and applications. In this paper we describe the deployment, validation and demonstration of the optical integrated testbed for the “GEneralized architecture for dYnamic infrastructure SERviceS” (GEYSERS) project to accommodate such cloud based Infrastructure Services. The GEYSERS testbed is composed of a set of local physical testbeds allocated in the facilities of the GEYSERS partners. It is built up based on the requirements specification, architecture definition and per-layer development that constitutes the whole GEYSERS ecosystem, and validates the procedures on the GEYSERS prototypes. The testbed includes optical devices (layer 1), switches (layer 2), and IT resources deployed in different local testbeds provided by the project partners and interconnected among them to compose the whole testbed layout. The main goal of the GEYSERS testbed is twofold. On one hand, it aims at providing a validation ground for the architecture, concepts and business models proposed by GEYSERS, sustained by two main paradigms: Infrastructure as a Service (IaaS) and the coupled provisioning of optical network and IT resources. On the other hand, it is used as a demonstration platform for testing the software prototypes within the project and to demonstrate to the research and business community the project approach and solutions. In this work, we discuss our experience in the deployment of the testbed and share the results and insights learned from our trials in the process. Additionally, the paper highlights the most relevant experiments carried out in the testbed, aimed at the validation of the overall GEYSERS architecture

Performance evaluation of the multiple output queueing switch with different buffer arrangements strategy

Performance evaluation of the multiple output queueing (MOQ) switch recently proposed by us is discussed in this paper. In the MOQ switch both the switch fabric and buffers can operate at the same speed as input and output ports. This solution does not need any speedup in the switch fabric as well as any matching algorithms between inputs and outputs. In this paper new performance measures for the proposed MOQ switch are evaluated. The simulation studies have been carried out for switches with different buffer arrangements strategy and of capacity 2×2, 4×4, 8×8, 16×16 and 32×32, and under selected traffic patterns. The simulations results are also compared with OQ switches of the same sizes

Hydrodynamic aspects of the stability of the vapour-gas channel in beam welding methods

Translated from Russian (Fiz. Khim. Obrab. Mater. 1996 (4) p. 74-82)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(VR-Trans--9199)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo