Markos P. Anastasopoulos

Energy Efficiency in integrated IT and optical network infrastructures: The GEYSERS approach

In this paper we propose energy efficient design and operation of infrastructures incorporating integrated optical network and IT resources. For the first time we quantify significant energy savings of a complete solution jointly optimizing the allocation and provisioning of both network and IT resources. Our approach involves virtualization of the infrastructure resources and it is proposed and developed in the framework of the European project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services.

Converged optical network and data center virtual infrastructure planning

This paper presents a detailed study of planning virtual infrastructures (VIs) over a physical infrastructure comprising integrated optical network and data center resources with the aim of enabling sharing of physical resources among several virtual operators and services. Through the planning process, the VI topology and virtual resources are identified and mapped to the physical resources. Our study assumes a practical VI demand model without any in advance global knowledge of the VI requests that are handled sequentially. Through detailed integer linear program modeling, two objective functions - one that minimizes the overall power consumption of the infrastructure and one that minimizes the wavelength utilization - are compared. Both are evaluated for the virtual wavelength path and wavelength path optical network architectures. The first objective results in power consumption savings and the two optical network architectures provide similar performances. However, the trend changes for higher load values, due to the inefficient wavelength utilization that the first objective leads to. Finally, we compare the virtual infrastructures created by the two objectives through online traffic provisioning simulations. The objective minimizing wavelength utilization results in VIs suffering higher request blocking compared to the VIs created by the objective minimizing the overall power consumption.

Planning of dynamic virtual optical cloud infrastructures: The GEYSERS approach

This article focuses on planning and replanning of virtual infrastructures over optical cloud infrastructures comprising integrated optical network and IT resources. This concept has been developed in the context of the European project GEYSERS. GEYSERS has proposed a novel multi-layer architecture, described in detail, that employs optical networking capable of provisioning optical network and IT resources for end-to-end cloud service delivery. The procedures required to perform virtual infrastructure planning and replanning at the different architecture layers are also detailed. An optimization scheme suitable to dynamically plan and replan virtual infrastructures is presented and compared to conventional approaches, and the benefits of dynamic replanning are discussed and quantified. The final project demonstration, focusing on planning, replanning, and dynamically establishing virtual infrastructures over the physical resources, is presented, while some emulation results are provided to further evaluate the performance of the GEYSERS solution.

Energy aware planning of multiple virtual infrastructures over converged optical network and IT physical resources

This paper studies energy efficient planning of multiple concurrent infrastructures incorporating integrated optical network and IT resources. An MILP model for virtualization of the underlying physical resources is proposed and validated achieving significant energy savings.

Stochastic virtual infrastructure planning in elastic cloud deploying optical networking

This paper proposes stochastic planning suitable for elastic clouds deploying optical networking. A novel model employing stochastic traffic considerations for virtualization of the underlying physical resources is proposed and validated achieving significant cost savings.

Adaptive virtual infrastructure planning over interconnected IT and optical network resources using evolutionary game theory

This paper focuses on integrated optical network and IT infrastructures in support of the Future Internet and its new emerging applications. In this context, the concept of virtualization of the physical infrastructure is proposed and the process of virtual infrastructure planning is discussed. A novel optimization scheme suitable to adaptively plan virtual infrastructures employing evolutionary game theory is presented and compared to conventional centralized approaches. Our evolutionary game theory modelling results clearly show, that given sufficient time to learn the status of the underlying physical topology the virtual infrastructures planned have similar performance to those generated through traditional global optimization approaches such as integer linear programming.

Hardware virtualized flexible network for wireless data-center optical interconnects [invited]

Future networks are set to provide a wide range of services over a multitude of technologies carrying a broad range of traffic profiles. The emerging mobile cloud computing applications are imposing numerous challenges on network operators to enable ubiquitous and on-demand service provisioning. To cope with the rising demands wired and wireless networks, together with IT infrastructures, need to be part of a converged platform. They should allow end-to-end network and cloud composition and visualization, which are required for ubiquitous and distributed access. Flexible and programmable optical networks can integrate and merge IT and wireless technologies effectively and efficiently. In view of this, we propose the use of a time shared optical network (TSON) for the interconnection of wireless access networks and IT resources and expand its functionality and dynamicity for integration in a converged yet heterogeneous environment. TSON is also extended to facilitate a virtualization-enabled multi-technology echo system. The extensions aim at facilitating hardware virtualization of the TSON technology and include support of higher rates, flexible subwavelength or wavelength modes of operation, and dynamic memory allocation facilitating infrastructure virtualization and re-programming. An experimental implementation evaluates the impact of TSONs variable aggregation buffer memory requirements on different frame sizes and its effect on network bandwidth and latency. Using experimental data, simulation studies introduce and investigate large-scale scenarios of hardware virtualization and investigate the resource efficiency advantages enabled by the proposed solution. A theoretical evaluation of the network performance of the proposed TSON solution is also provided, and results on the delay performance of the converged infrastructure and the associated trade-offs are presented.

Stochastic planning of dependable virtual infrastructures over optical datacenter networks

This paper focuses on the design of multiple dependable virtual infrastructures (VIs) over converged optical network and IT resources supporting uncertain elastic cloud services. VI dependability is defined as the VI ability to offer resilience in the case of IT resource failures and security guarantees in terms of isolation of VIs that share a common physical infrastructure. The VI planning optimization objective is to minimize the overall energy consumption. To address these issues together with the time variability and uncertainty of elastic cloud services, a novel VI planning scheme based on stochastic linear programming (SLP) is proposed. To cope with the increasing computational complexity inherently imposed in SLP formulations, the sample average approximation technique and Lagrangian relaxation are used to solve the SLP problem in an efficient manner. Our modeling results illustrate interesting trade-offs between the overall energy consumption of the VIs and the dependability impact on the energy consumption and the utilization of the infrastructure resources.

Content Project: Considerations Towards a Cloud-Based Internetworking Paradigm

Although cloud computing and the Software Defined Network (SDN) framework are fundamentally changing the way we think about network services, multi-domain and multi-technology problems are not sufficiently investigated. These multi-domain, end-to-end problems concern communication paths that span from the wireless access and the wireless backhaul networks to the IT resources through optical networks. In this paper we present the CONTENT project approach to network and infrastructure virtualization over heterogeneous, wireless and metro optical networks, that can be used to provide end-to-end cloud services. The project goal is to drive innovation across multi-technology infrastructures and allow ICT to be delivered and consumed as a service by Virtual Network Operators. The communication mechanics between wireless and optical domains and the physical layer abstractions of a CONTENT Virtual Network are presented and the relation of the proposed approach with the SDN framework is investigated.

Virtual Infrastructure Planning in Elastic Cloud Deploying Optical Networking

This paper studies energy efficient planning of elastic cloud deploying optical network infrastructures. An MILP model employing multi-service, multi-period considerations for virtualization of the underlying physical resources is proposed and validated achieving significant energy savings.