Joint Bandwidth Assignment and Routing for Power Saving on Large File Transfer with Time Constraints

The increase in network traffic in recent years has led to increased power consumption. Accordingly, many studies have tried to reduce the energy consumption of network devices. Various types of data have become available in large quantities via large high-speed computer networks. Time-constrained file transfer is receiving much attention as an advanced service. In this model, a request must be completed within a user-specified deadline or rejected if the requested deadline cannot be met. Some bandwidth assignment and routing methods to accept more requests have been proposed. However, these existing methods do not consider energy consumption. Herein, we propose a joint bandwidth assignment and routing method that reduces energy consumption for time-constrained large file transfer. The bandwidth assignment method reduces the power consumption of mediate node, typically router, by waiting for requests and transferring several requests at the same time. The routing method reduces the power consumption by selecting the path with the least predicted energy consumption. Finally, we evaluate the proposed method through simulation experiments

Energy Efficient Content Distribution

To optimize energy efficiency in network, operators try to switch off as many network devices as possible. Recently, there is a trend to introduce content caches as an inherent capacity of network equipment, with the objective of improving the efficiency of content distribution and reducing network congestion. In this work, we study the impact of using in-network caches and CDN cooperation on an energy-efficient routing. We formulate this problem as Energy Efficient Content Distribution. The objective is to find a feasible routing, so that the total energy con- sumption of the network is minimized subject to satisfying all the demands and link capacity. We exhibit the range of parameters (size of caches, popularity of content, demand intensity, etc.) for which caches are useful. Experiment results show that by placing a cache on each backbone router to store the most popular content, along with well choosing the best content provider server for each demand to a CDN, we can save a total up to 23% of power in the backbone, while 16% can be gained solely thanks to caches.Pour optimiser l'efficacité énergétique dans un réseau, les opérateurs doivent éteindre un nombre maximum d'équipements réseau. Récemment, il a été propose de rajouter des caches à l'intérieur des nœuds réseaux dans l'objectif d'améliorer la distribution de contenus et de réduire la congestion des réseaux. Dans ce travail, nous étudions l'impact de l'utilisation de caches réseaux (in- network caches) et de leur coopération avec les Content Delivery Networks (CDN) sur l'énergie consommée par le routage. Nous modélisons ce problème, la Distribution de Données Efficace en Énergie. L'objectif est de trouver un routage réalisable qui minimise la consommation énergétique du réseau tout en satisfaisant les demandes de contenus. Nous exhibons les valeurs des paramètres (tailles des caches, popularités des données, ...) pour lesquelles ces caches sont utiles. Des expérimentations montrent qu'en plaçant un cache sur chaque routeur d'un réseau backbone pour stocker le contenu le plus populaire, ainsi qu'on choisissant le meilleur serveur pour chaque demande 'a un CDN, jusqu'à 23% de l'énergie du backbone peut être sauvée, dont 16% du gain est du aux seuls caches

Green IT - dynamic network topologies

All engineering disciplines are influenced by the global focus on energy consumption reduction and sustainability. Due to its resident inefficiency, The ICT sector is of particular concern, and there has been extensive work to develop sustainability enhancements to networks and/or network devices. Previous work presented dynamic topology concepts in which the behaviour and topology of the devices and the network react dynamically in response to traffic demands, with the intent of placing devices into standby states to reduce energy consumption. The key aim of this study is to develop a dynamic topology mechanism implementation; it proposes a testbed environment and corresponding dynamic topology mechanism that makes use of two programs: one running on a centralised controller, and one running on the network nodes. The former determines the optimal topology based on energy consumption reductions and network traffic, while the latter uses MPLS to implement the topology. The testbed is used to determine the dynamic topology mechanism’s effectiveness and impact on network performance, and does so by subjecting it to controlled variations in network traffic. Quantitative measurements of the dynamic topology mechanism’s network performance metrics are presented and analysed relative to baseline measurements. The analysis shows that the dynamic topology mechanism is quite effective, as the effect on network performance is mostly minimal and the reaction to network traffic variations is sufficiently swift. The system takes approximately 30 seconds to react to traffic variations and implement topology changes, and has negligible effect on jitter, packet loss, and the number of out of order packets. However, it produces an average increase in delay of 8 ms, the source of which requires further investigation. This study proves the feasibility of dynamic topology mechanism implementation, and provides a framework for further development and eventual widespread deployment