Giacomo Bernini

All-optical packet/circuit switching-based data center network for enhanced scalability, latency, and throughput

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 todays electrical DCNs throPugh 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 transmission technologies with superior flexibility, manageability, and customizability.

SDN-enabled OPS with QoS guarantee for reconfigurable virtual data center networks

Optical packet switching (OPS) can enhance the performance of data center networks (DCNs)by providing fast and large-capacity switching capability. Benefiting from the software-defined networking (SDN) control plane, which could update the look-up-table (LUT) of the OPS, virtual DCNs can be flexibly created and reconfigured. In this work, we have implemented and assessed an SDN-based control framework for an OPS node, where the OpenFlow protocol has been extended in support of the OPS switching paradigm. Application flows are switched by the OPS at submicrosecond hardware speed, decoupled from the slower (millisecond timescale) SDN control operation. By the DCN infrastructure provider, the virtual networks become directly programmable with the abstraction of the underlying OPS node. Experimental results validate the successful setup of virtual network slices for intra-data center interconnect and quality of service (QoS) guarantee for high-priority application flows. Data plane resources are efficiently shared by exploiting statistical multiplexing. In addition, the capability of exposing per-port OPS traffic statistics information to the SDN controller enables the implementation and experimental validation of load balancing algorithms to improve the QoS performance.

Multi-Tenant Software-Defined Hybrid Optical Switched Data Centre

We introduce a holistic solution for software-defined optical data centres (DC). Hybrid optical circuit/packet switching technologies are employed in the data plane, while a software-defined networking (SDN) controller based on OpenDaylight with significant extensions is adopted for the data centre network (DCN) control and management. Novel functional modules in the SDN controller together with its northbound (NBI) and southbound interfaces (SBI) are designed and developed. The OpenFlow protocol is extended at the SBI to support communication between the extended OpenDaylight SDN controller and the optical DCN devices. Over the NBIs, DC applications and the cloud management system directly interact with the optical DCN. A virtual data centre (VDC) application is designed and developed that dynamically creates and provisions multiple coexisting but isolated VDCs. An optical network-aware virtual machine (VM) placement method is proposed and implemented for a single-step deployment of both network and IT (VM) resources to accommodate the VDC requests. The VDC deployment process is extensively simulated and experimentally demonstrated.

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.

Lightness: A Function-Virtualizable Software Defined Data Center Network With All-Optical Circuit/Packet Switching

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 the currently deployed computing and network infrastructure. All-optical 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 deeply programmable 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 and virtual network functions (VNF) on top of the data plane. We experimentally demonstrate realistic intra DCN 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 element. Results demonstrate a fully functional complete unification of an advanced optical data plane with an SDN control plane, promising more efficient management of the next-generation data center compute and network resources.

ORCHESTRA - Optical performance monitoring enabling flexible networking

An optical network, like any system, has to be observable before it can become subject to optimization, and this is the main capability that ORCHESTRA project introduces. ORCHESTRAs high observability will rely on information provided by the coherent transceivers that can be extended, almost for free, to operate as software defined optical performance monitors (soft-OPM). Novel digital signal processing (DSP) OPM algorithms will be developed and combined with a novel hierarchical monitoring plane, cross-layer optimization algorithms and active-control functionalities. ORCHESTRA vision is to close the control loop, enabling true network dynamicity and unprecedented network capacity efficiency.

Demonstration of low latency Intra/Inter Data-Centre heterogeneous optical Sub-wavelength network using extended GMPLS-PCE control-plane

This paper reports on the first user/application-driven multi-technology optical sub-wavelength network for intra/inter Data-Centre (DC) communications. Two DCs each with distinct sub-wavelength switching technologies, frame based synchronous TSON and packet based asynchronous OPST are interconnected by a WSON inter-DC communication. The intra/inter DC testbed demonstrates ultra-low latency (packet-delay <270 µs and packet-delay-variation (PDV)<10 µs) flexible data-rate traffic transfer by point-to-point, point-to-multipoint, and multipoint-to-(multi)point connectivity, highly suitable for cloud based applications and high performance computing (HPC). The extended GMPLS-PCE-SLAE based control-plane enables innovative application-driven end-to-end sub-wavelength path setup and resource reservation across the multi technology data-plane, which has been assessed for as many as 25 concurrent requests.

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.

Dynamic Reconfiguration in 5G Mobile Networks to Proactively Detect and Mitigate Botnets

Botnets are one of the most powerful cyberthreats affecting continuity and delivery of existing network services. Detecting and mitigating attacks promoted by botnets become a greater challenge with the advent of 5G networks, as the number of connected devices with high mobility capabilities, the volume of exchange data, and the transmission rates increase significantly. Here, a 5G-oriented solution is proposed for proactively detecting and mitigating botnets in a highly dynamic 5G network. 5G subscribers’ mobility requires dynamic network reconfiguration, which is handled by combining software-defined network and network function virtualization techniques.

Optical wireless network convergence in support of energy-efficient mobile cloud services

Mobile computation offloading has been identified as a key-enabling technology to overcome the inherent processing power and storage constraints of mobile end devices. To satisfy the low-latency requirements of content-rich mobile applications, existing mobile cloud computing solutions allow mobile devices to access the required resources by accessing a nearby resource-rich cloudlet, suffering increased capital and operational expenditures. To address this issue, in this paper, we propose an infrastructure and architectural approach based on the orchestrated planning and operation of optical data center networks and wireless access networks. To this end, a novel formulation based on a multi-objective nonlinear programming model is presented that considers energy-efficient virtual infrastructure planning over the converged wireless, optical network interconnecting DCs with mobile devices, taking a holistic view of the infrastructure. Our modelling results identify trends and trade-offs relating to end-to-end service delay, mobility, resource requirements and energy consumption levels of the infrastructure across the various technology domains.