ata centers (DCs) are currently the largest closedloop systems in the information technology (IT) and networking worlds, continuously growing toward multi-million-node clouds [1]. DC operators manage and control converged IT and network infrastructures in order to offer a broad range of services and applications to their customers. Typical services and applications provided by current DCs range from traditional IT resource outsourcing (storage, remote desktop, disaster recovery, etc.) to a plethora of web applications (e.g., browsers, social networks, online gaming). Innovative applications and services are also gaining momentum to the point that they will become main representatives of future DC workloads. Among them, we can find high-performance computing (HPC) and big data applications [2]. HPC encompasses a broad set of computationally intensive scientific applications, aiming to solve highly complex problems in the areas of quantum mechanics, molecular modeling, oil and gas exploration, and so on. Big data applications target the analysis of massive amounts of data collected from people on the Internet to analyze and predict their behavior.All these applications and services require huge data exchanges between servers inside the DC, supported over the DC network (DCN): the intra-DC communication network. The DCN must provide ultra-large capacity to ensure high throughput between servers. Moreover, very low latencies are mandatory, particularly in HPC where parallel computing tasks running concurrently on multiple servers are tightly interrelated. Unfortunately, current multi-tier hierarchical tree-based DCN architectures relying on Ethernet or Infiniband electronic switches suffer from bandwidth bottlenecks, high latencies, manual operation, and poor scalability to meet the expected DC growth forecasts [3].These limitations have mandated a renewed investigation D Abstract Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor flexible enough to efficiently and cost-effectively support highly dynamic application traffic profiles. The FP7 European Project LIGHTNESS foresees extending the capabilities of today's electrical DCNs through the introduction of optical packet switching and optical circuit switching paradigms, realizing together an advanced and highly scalable DCN architecture for ultra-high-bandwidth and low-latency server-to-server interconnection. This article reviews the current DC and high-performance computing (HPC) outlooks, followed by an analysis of the main requirements for future DCs and HPC platforms. As the key contribution of the article, the LIGHTNESS DCN solution is presented, deeply elaborating on the envisioned DCN data plane technologies, as well as on the unified SDN-enabled control plane architectural solution that will empower OPS and OCS transm...

This paper presents on-going research to develop the Intercloud Architecture Framework (ICAF) that addresses problems in multi-provider multi-domain heterogeneous cloud based infrastructure services and applications integration and interoperability. The paper refers to existing standards in Cloud Computing, in particular, recently published NIST Cloud Computing Reference Architecture (CCRA). The proposed ICAF defines four complementary components addressing Intercloud integration and interoperability: multi-layer Cloud Services Model (CSM) that combines commonly adopted cloud service models, such as IaaS, PaaS, SaaS, in one multilayer model with corresponding inter-layer interfaces including also access and delivery infrastructure layer; Intercloud Control and Management Plane (ICCMP) that supports cloud based applications interaction; Intercloud Federation Framework (ICFF), and Intercloud Operation Framework (ICOF). The paper provides general definition of the ICFF, its generic components and interfaces. The paper briefly describes the architectural framework for cloud based infrastructure services provisioned on-demand being developed in the framework of the GEYSERS project that provides a basis for CSM and ICCMP implementation allowing optimized provisioning of computing, storage and networking resources. The proposed architecture is intended to provide an architectural model for developing Intercloud middleware and in this way will facilitate clouds interoperability and integration.

Abstract-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.

Abstract-Modern high-performance Data Centers are responsible for delivering a huge variety of cloud applications to the end-users, which are increasingly pushing the limits of currently deployed computing and network infrastructure. Alloptical dynamic data center network (DCN) architectures are strong candidates to overcome those adversities, especially when they are combined with an intelligent software defined control plane. In this paper, we report the first harmonious integration of an optical flexible hardware framework operated by an agile software and virtualization platform. The LIGHTNESS deeplyprogrammable all-optical circuit and packet switched data plane is able to perform unicast/multicast switch-over on-demand, while the powerful Software Defined Networking (SDN) control plane enables the virtualization of computing and network resources creating a virtual data center (VDC) and virtual network functions (VNF) on top of the data plane. We experimentally demonstrate realistic intra data center networking with deterministic latencies for both unicast and multicast, showcasing monitoring and database migration scenarios each of which is enabled by an associated network function virtualization (NFV) element. Results demonstrate a fully-functional complete unification of advanced optical data plane with an SDN control plane, promising more efficient management of the next-generation data center compute and network resources.

Network slicing has emerged as a major new networking paradigm for meeting the diverse requirements of various vertical businesses in virtualised and softwarised 5G networks. SliceNet is a project of the EU 5G Infrastructure Public Private Partnership (5G PPP) and focuses on network slicing as a cornerstone technology in 5G networks, and addresses the associated challenges in managing, controlling and orchestrating the new services for users especially vertical sectors, thereby maximising the potential of 5G infrastructures and their services by leveraging advanced software networking and cognitive network management. This paper presents the vision of the SliceNet project, highlighting the gaps in existing work and challenges, the proposed overall architecture, proposed technical approaches, and use cases.