Energy efficiency considerations in integrated IT and optical network resilient infrastructures

The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources

A long-range dependent model for network traffic with flow-scale correlations

International audienceFor more than a decade, it has been observed that network traffic exhibits long-range dependence and many models have been proposed relating this property to heavy-tailed flow durations. However, none of these models consider correlations at flow scale. Such correlations exist and will become more prominent in the future Internet with the emergence of flow-aware control mechanisms correlating a flow's transmission to its characteristics (size, duration, etc.). In this work, we study the impact of the correlation between flow rates and durations on the long-range dependence of aggregate traffic. Our results extend those of existing models by showing that two possible regimes of long-range dependence exist at different time scales. The long-range dependence in each regime can be stronger or weaker than standard predictions, depending on the conditional statistics between the flow rates and durations. In the independent case, our proposed model consistently reduces to former approaches. The pertinence of our model is validated on real web traffic traces, and its ability to accurately explain the Hurst parameter is validated on both web traces and numerical simulations

Flexible and Dynamic Control of Network QoS in Grid environments: the QoSINUS approach.

International audienceGrids rely on a complex interconnection of IP domains that may exhibit changing performance characteristics and may offer different quality of service (QoS) facilities. We examine the case of a biomedical application distributed over a grid and show it may suffer from uncontrolled communication performance. Then we present the QoSINUS service that dynamically allocates the network resources to Grid flows in order to match their specific QoS requirements under different load conditions. The aim of this approach is to optimize the end to end performances the heterogeneous mix of grid flows get from the network to enhance the individual application's performance as well as the overall grid infrastructure performance and utilization level. The QoSINUS service is based on the programmable network approach that offers flexibility, evolutivity and enables dynamic adaptation to network load variations. Finally, results of QoSINUS experiments conducted in the context of the eToile french grid testbed based on the high speed and DiffServ capable research network infrastructure, VTHD, are presented

Planning data transfers in grids: a multi-service queueing approach

Grid applications move large amounts of data between distributed resources, and the efficiency of a Grid depends on their timely delivery within given bounds (deadlines). In most cases, the data volume and deadline are known in advance, allowing for both network planning and connection admission control (CAC). We formally define the problem and, based on this formalization, describe the operation of a feasible procedure for network reservations of deadline-constrained bulk data transfer requests. The procedure guarantees a minimum bandwidth to meet the deadlines and allows for opportunistic utilization of residual network capacity. We propose a novel analytical model based on the solution of an M/M(nc)/1/k(s)−RPS queue. The analytical model is validated against ns−2 simulations taking into account network level details (IP and TCP protocols), showing remarkably good coherence even under heavy loads. The model is orders of magnitude faster than simulation, which enables its application to plan the capacity of Grid networks, and to enforce CAC under the hypothesis of a dominating bottleneck on the transfer route

Co-promotor:

ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus Mw. prof. dr. D.C. van den Boom ten overstaan van een door het college voor promoties ingestelde commissie, in het openbaar te verdedigen in de Agnietenkape

Large Scale Gigabit Emulated Testbed for Grid Transport Evaluation

Abstract — Evaluating the performance of Grid applications running on high performance platforms interconnected by high speed and long distance networks with new transport services and protocols is highly required. This paper presents the eWAN integrated environment enabling large scale grid emulation at gigabit speed. It discusses features provided to control key characteristics (topology, round trip time, packet size, drop rate, link capacity) of an evaluation scenario. A method to increase the accuracy of rate control under various delay configuration is proposed and some experimental results are detailled