Tran Manh Nam

ECODANE: A customizable hybrid testbed for green data center networks

In this paper we propose a new testbed architecture that combines hardware network devices with virtual emulation test environment to improve scalability, flexibility and accuracy. The testbed enables to design and experiment new concepts for energy-efficient data center. It is based on OpenFlow, a Software Defined Networking (SDN) technology that facilitates the deployment of energy-aware protocols and mechanisms.

A reliable analyzer for energy-saving approaches in Large Data Center Networks

Nowadays a big effort has been paid to make energy-efficient Data Center Networks (DCNs). There are several proposed solutions to reduce the energy consumption in DCN. However, for researchers, it is difficult to evaluate the energy saving performance of those approaches in a large-size network due to the testbed/emulation environment limitation. In this paper we construct a Performance Evaluation Simulator (called GreenDC Analyzer) that can model a large DCN of thousands of servers. The tool is shown to have a reliability and flexibility in processing and providing accurate and stable performance evaluations with various switch types, and different energy-saving schemes under the same traffic conditions. The tool also allows us to have a deeper investigation of the energy saving performance for the two well-known energy-saving schemes: Power Scaling and Idle Logic. In the bottom line, the Analyzer could be a useful tool for researchers to study pros and cons of different energy-saving approaches in a data center.

An Energy-Aware Embedding Algorithm for Virtual Data Centers

Cloud computing has emerged in the recent years as a promising paradigm that facilitates such new service models as Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). As the number of cloud service provider increases, there exists a demand to dynamically provision virtual data centers (VDC) on top of the infrastructure providers physical data centers. This research addresses problems related to embedding virtual data centers inside physical data centers. VDC embedding is challenging as it is an NP-hard problem that should meet multiple objectives. In the paper, we propose a new heuristic VDC embedding algorithm that takes into account energy consumption as well as physical resources of data centers. We also realize this virtualization paradigm based on a Software-Defined Network architecture.

Joint Vertical Handoff and Resource Allocation in OFDMA/TDD Systems based on Software-Defined Wireless Network

One considerable challenge in future heterogeneous wireless networks (HetNet) is vertical handover. Current vertical handover approaches almost focus on resolving two questions: (1) when a Mobile Station (MS) needs to carry out a vertical handover (VHO) procedure; and (2) how a proper handover decision can be made in a HetNet environment. Actually, some approaches do not guarantee that MS can avoid handover flapping due to continuous changes in AP/BTS association. In addition, after MS joins in a new environment, many solutions do not care if VHO candidates meet requirements on QoS, such as fairness and throughput due to channel dynamicity. In this paper, we propose two algorithms: the VHO decision-making algorithm and proportional fair over HetNets (PFoHN) algorithm. VHO decision-making algorithm determines the network selection based on the availability of the target network. After VHO process is finished, resource allocation is performed by the PFoHN algorithm. In our study, the proposed approaches are developed with the support of Software-Defined Wireless Network technologies. Performance results show that PFoHN outperforms the Proportional Fair (PF) in terms of bandwidth and resource fairness, it also remarkably improves the overall system spectral efficiency.

Green data center using centralized power-management of network and servers

Green data center is becoming more recognized as a likely key trend in the future of Information and Communications Technologies. It attracts growing interest among many scientists today due to many of its possessed benefits, such as increasing energy saving levels, cost reductions, as well as decreasing carbon emissions. In a data center, Server Virtualization and Live Migration technologies facilitate efficient load balancing and reduction in power consumption of servers. Although using these technologies has many benefits, they do not, however, take energy-efficiency of the network devices such as routers, switches into consideration. In this paper, we construct an energy-efficient data center by combining server consolidation and idle logic approach of the data center network. The idle logic approach allows reducing power consumption of network devices by rapidly turning off sub-components when no activities are performed, and by re-waking them up when the system receives new activities. The results show that our combination reduces the consumed energy of network devices as well as servers.

Joint network embedding and server consolidation for energy–efficient dynamic data center virtualization

Abstract Cloud computing has emerged in recent years as a promising paradigm that facilitates such new service models as Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). As the number of cloud service provider increases, there exists a demand to dynamically provision virtual data centers (VDC) on top of the infrastructure provider’s physical data centers. This research addresses problems related to energy and resource efficiently embedding virtual data centers inside physical data centers under dynamic resource allocation conditions, in which VDCs continuously join and leave the system. Dynamic VDC embedding is challenging as it is an NP-hard problem that should meet multiple objectives. In this article, we propose heuristic joint VDC embedding – server consolidation approaches as one solution for that problem. Evaluation results show that the joint approach outperforms existing ones in terms of resource and energy efficiency and can keep system complexity acceptable.

Reducing Middle Nodes Mapping Algorithm for Energy Efficiency in Network Virtualization

For the future of the Internet, Network Virtualization and Software-Defined Networking (SDN) are recognized as key technologies. They reshape computing and network architectures, provide a number of advantages including centralized management, scalability and resource optimization. Along with the Internet’s development, the networking devices such as routers and switches are notable part of the large energy consumption of ITC. The design of high performance and energy-efficient network by using virtualization and SDN becomes an importance issue. In this paper we heuristic present energy-efficient algorithms for virtual network embedding. The experimental results show the remarkable energy-saving level of their approaches while maintaining the acceptance ratio.

The new method to save energy for Openflow Switch based on traffic engineering

Improving energy efficiency in network equipments and data centers is becoming an increasingly important research topic. Recent researches on energy saving for green data center aim to solve problem: How to make the energy consumption is proportional to the actual traffic on the network. In this paper, we present a design aimed at reducing the power consumption for Openflow Switches while guaranteeing the Quality of Service (QoS). Firstly, we design the Performance Switch to save energy according to input traffic. When there is not any traffic going through the switch then operating frequence will automatically reduce to 0 MHz and it is changed to 125MHz in case the switch receives and transmits data. Finally, we describe our test system and performance evaluations. Experimental results show excellent evident in energy saving according to various ranges of traffic load. Our switches can save about 30%-35% of power consumption compared with normal Openflow switch.