Erreichen von Performance in Netzwerken-On-Chip für Echtzeitsysteme

In many new applications, such as in automatic driving, high performance requirements have reached safety critical real-time systems. Consequently, Networks-on-Chip (NoCs) must efficiently host new sets of highly dynamic workloads e.g., high resolution sensor fusion and data processing, autonomous decision’s making combined with machine learning. The static platform management, as used in current safety critical systems, is no more sufficient to provide the needed level of service. A dynamic platform management could meet the challenge, but it usually suffers from a lack of predictability and the simplicity necessary for certification of safety and real-time properties. In this work, we propose a novel, global and dynamic arbitration for NoCs with real-time QoS requirements. The mechanism decouples the admission control from arbitration in routers thereby simplifying a dynamic adaptation and real-time analysis. Consequently, the proposed solution allows the deployment of a sophisticated contract-based QoS provisioning without introducing complicated and hard to maintain schemes, known from the frequently applied static arbiters. The presented work introduces an overlay network to synchronize transmissions using arbitration units called Resource Managers (RMs), which allows global and work-conserving scheduling. The description of resource allocation strategies is supplemented by protocol design and verification methodology bringing adaptive control to NoC communication in setups with different QoS requirements and traffic classes. For doing that, a formal worst-case timing analysis for the mechanism has been proposed which demonstrates that this solution not only exposes higher performance in simulation but, even more importantly, consistently reaches smaller formally guaranteed worst-case latencies than other strategies for realistic levels of system's utilization. The approach is not limited to a specific network architecture or topology as the mechanism does not require modifications of routers and therefore can be used together with the majority of existing manycore systems. Indeed, the evaluation followed using the generic performance optimized router designs, as well as two systems-on-chip focused on real-time deployments. The results confirmed that the proposed approach proves to exhibit significantly higher average performance in simulation and execution.In vielen neuen sicherheitskritische Anwendungen, wie z.B. dem automatisierten Fahren, werden große Anforderungen an die Leistung von Echtzeitsysteme gestellt. Daher müssen Networks-on-Chip (NoCs) neue, hochdynamische Workloads wie z.B. hochauflösende Sensorfusion und Datenverarbeitung oder autonome Entscheidungsfindung kombiniert mit maschineller Lernen, effizient auf einem System unterbringen. Die Steuerung der zugrunde liegenden NoC-Architektur, muss die Systemsicherheit vor Fehlern, resultierend aus dem dynamischen Verhalten des Systems schützen und gleichzeitig die geforderte Performance bereitstellen. In dieser Arbeit schlagen wir eine neuartige, globale und dynamische Steuerung für NoCs mit Echtzeit QoS Anforderungen vor. Das Schema entkoppelt die Zutrittskontrolle von der Arbitrierung in Routern. Hierdurch wird eine dynamische Anpassung ermöglicht und die Echtzeitanalyse vereinfacht. Der Einsatz einer ausgefeilten vertragsbasierten Ressourcen-Zuweisung wird so ermöglicht, ohne komplexe und schwer wartbare Mechanismen, welche bereits aus dem statischen Plattformmanagement bekannt sind einzuführen. Diese Arbeit stellt ein übergelagertes Netzwerk vor, welches Übertragungen mit Hilfe von Arbitrierungseinheiten, den so genannten Resource Managern (RMs), synchronisiert. Dieses überlagerte Netzwerk ermöglicht eine globale und lasterhaltende Steuerung. Die Beschreibung verschiedener Ressourcenzuweisungstrategien wird ergänzt durch ein Protokolldesign und Methoden zur Verifikation der adaptiven NoC Steuerung mit unterschiedlichen QoS Anforderungen und Verkehrsklassen. Hierfür wird eine formale Worst Case Timing Analyse präsentiert, welche das vorgestellte Verfahren abbildet. Die Resultate bestätitgen, dass die präsentierte Lösung nicht nur eine höhere Performance in der Simulation bietet, sondern auch formal kleinere Worst-Case Latenzen für realistische Systemauslastungen als andere Strategien garantiert. Der vorgestellte Ansatz ist nicht auf eine bestimmte Netzwerkarchitektur oder Topologie beschränkt, da der Mechanismus keine Änderungen an den unterliegenden Routern erfordert und kann daher zusammen mit bestehenden Manycore-Systemen eingesetzt werden. Die Evaluierung erfolgte auf Basis eines leistungsoptimierten Router-Designs sowie zwei auf Echtzeit-Anwendungen fokusierten Platformen. Die Ergebnisse bestätigten, dass der vorgeschlagene Ansatz im Durchschnitt eine deutlich höhere Leistung in der Simulation und Ausführung liefert

ACINO: Second year report on dissemination and communication activities

This ACINO deliverable presents the communication and dissemination activities performed by the consortium during the first two years of the project. We have communicated using our website, Twitter account and by various communication actions: The website saw over 3000 unique visitors during the first year and over 4000 during the second year; The consortium Twitter account had 49 followers at the end of the first year and 80 at the end of the second year. We posted 50 tweets during the first year and 40 more during the second year; We also held a press release and an interview in a magazine during the first year, and had three more similar communication actions during the second year. The dissemination activities have been composed of participation in public events where the goals and concepts of ACINO were presented via publications, presentation, workshops, courses and demonstrations. Overall, over forty different dissemination activities have been performed: An article has been published in peer-reviewed, open access Journal of Green Engineering; Eighteen articles have been published in conferences: four during the first year and fourteen during the second. One of them was a post-deadline and six were invited papers; We have co-organised three workshops: the Workshop on Network Function Virtualization and Programmable Networks at EUCNC 2015, the first Workshop on Multi-Layer Network Orchestration (NetOrch) at ICTON 2016 and the stand-alone ONOS/CORD workshop; We have held 16 talks, tutorial, courses and demonstrations; Consortium members have won two prizes for work related to ACINO: a team of developers won the 3rd prize of the ONOS Build Hackathon, and Telefónica won the Best SDN-NFV solution award at the LTE and 5G World conference by presenting a solution in which Sedona Systems was involved; We have contributed to six IETF standardisation documents and done some implementation and test of these standards. We have contributed to two open source projects: the NetPhony and ONOS controllers, with the implementation of main features being accepted and merged to the core code of these open source projects. Finally, the project has devised detailed plans for its dissemination activities for the last year of the project. We have: Confirmed plans for the organisation of a workshop, the second edition of the NetOrch workshop, co-located with the ICTON conference; A solid plan for continued dissemination in conferences (already five accepted conference papers, five talk invitations and a list of conferences of interest) and in peer-reviewed journals, with one article accepted for publication in the Journal of Lightwave Technology, two articles under review and plans for four more; Some more planned contribution to open source projects

Traffic allocation strategies in WSS-based dynamic optical networks

Elastic optical networking (EON) is a viable solution to meet future dynamic capacity requirements of Internet service provider and inter-datacenter networks. At the core of EON, wavelength selective switches (WSSs) are applied to individually route optical circuits, while assigning an arbitrary bandwidth to each circuit. Critically, the WSS control scheme and configuration time may delay the creation time of each circuit in the network. In this paper, we first detail the WSS-based optical data-plane implementation of a metropolitan network test-bed. Then, we review a software-defined networking (SDN) application designed to enable dynamic and fast circuit setup. Subsequently, we introduce a WSS logical model that captures the WSS time-sequence and is used to estimate the circuit-setup response time. Then, we present two batch service policies that aim to reduce the circuit-setup response time by bundling multiple WSS reconfiguration steps into a single SDN command. Resulting performance gains are estimated through simulation.Peer ReviewedPostprint (author's final draft

National oil companies and resource nationalism: a challenge for a petroleum resource-rich state.

Debates on the relevance of national oil companies (NOCs) as a means for a state to adequately manage their petroleum resources have been put forward by some critics. Some critics argue that the traditional national oil company model is antiquated. At first, national oil companies were set up as agents of the governments, primarily to exert control and ownership over the state’s petroleum resources. Developed Western governments did this. Recently, NOCs in petroleum developing states set up in line with government regulations and policies seek to convert the petroleum resources into valuable benefits for the people. This has not been the case in recent times, as the average citizen of these states barely benefits from the exploitation of petroleum resources. This research examined the theory of resource nationalism and the roles of NOCs in achieving government objectives. Further, the thesis examined the role of NOCs in the development of petroleum resources. NOCs have enormous potential to contribute to positive economic transformation in any country, especially countries that have an abundance of petroleum resources. Given the vast petroleum resources, economic development can be achieved provided that proper institutional and petroleum policy conditions are put in place. This thesis further reviews the roles NOCs play in the global petroleum industry, and in particular in their domestic petroleum industry. Furthermore, the thesis argues that for a petroleum-rich developing state that establishes a NOC, the extent of involvement of the NOC in the development of petroleum resources matters. Some NOCs take the backseat when it comes to the actual production of the petroleum resources. Further, they have been turned into rent collectors, as they barely engage in the production of the petroleum resources. Again, should the exploitation of the petroleum resources be left in the hands of the international oil companies, or should the public sector, preferably the NOC, play a leading role in the production of these petroleum resources

Optical Networks and Interconnects

The rapid evolution of communication technologies such as 5G and beyond, rely on optical networks to support the challenging and ambitious requirements that include both capacity and reliability. This chapter begins by giving an overview of the evolution of optical access networks, focusing on Passive Optical Networks (PONs). The development of the different PON standards and requirements aiming at longer reach, higher client count and delivered bandwidth are presented. PON virtualization is also introduced as the flexibility enabler. Triggered by the increase of bandwidth supported by access and aggregation network segments, core networks have also evolved, as presented in the second part of the chapter. Scaling the physical infrastructure requires high investment and hence, operators are considering alternatives to optimize the use of the existing capacity. This chapter introduces different planning problems such as Routing and Spectrum Assignment problems, placement problems for regenerators and wavelength converters, and how to offer resilience to different failures. An overview of control and management is also provided. Moreover, motivated by the increasing importance of data storage and data processing, this chapter also addresses different aspects of optical data center interconnects. Data centers have become critical infrastructure to operate any service. They are also forced to take advantage of optical technology in order to keep up with the growing capacity demand and power consumption. This chapter gives an overview of different optical data center network architectures as well as some expected directions to improve the resource utilization and increase the network capacity

Conserve and Protect Resources in Software-Defined Networking via the Traffic Engineering Approach

Software Defined Networking (SDN) is revolutionizing the architecture and operation of computer networks and promises a more agile and cost-efficient network management. SDN centralizes the network control logic and separates the control plane from the data plane, thus enabling flexible management of networks. A network based on SDN consists of a data plane and a control plane. To assist management of devices and data flows, a network also has an independent monitoring plane. These coexisting network planes have various types of resources, such as bandwidth utilized to transmit monitoring data, energy spent to power data forwarding devices and computational resources to control a network. Unwise management, even abusive utilization of these resources lead to the degradation of the network performance and increase the Operating Expenditure (Opex) of the network owner. Conserving and protecting limited network resources is thus among the key requirements for efficient networking. However, the heterogeneity of the network hardware and network traffic workloads expands the configuration space of SDN, making it a challenging task to operate a network efficiently. Furthermore, the existing approaches usually lack the capability to automatically adapt network configurations to handle network dynamics and diverse optimization requirements. Addtionally, a centralized SDN controller has to run in a protected environment against certain attacks. This thesis builds upon the centralized management capability of SDN, and uses cross-layer network optimizations to perform joint traffic engineering, e.g., routing, hardware and software configurations. The overall goal is to overcome the management complexities in conserving and protecting resources in multiple functional planes in SDN when facing network heterogeneities and system dynamics. This thesis presents four contributions: (1) resource-efficient network monitoring, (2) resource-efficient data forwarding, (3) using self-adaptive algorithms to improve network resource efficiency, and (4) mitigating abusive usage of resources for network controlling. The first contribution of this thesis is a resource-efficient network monitoring solution. In this thesis, we consider one specific type of virtual network management function: flow packet inspection. This type of the network monitoring application requires to duplicate packets of target flows and send them to packet monitors for in-depth analysis. To avoid the competition for resources between the original data and duplicated data, the network operators can transmit the data flows through physically (e.g., different communication mediums) or virtually (e.g., distinguished network slices) separated channels having different resource consumption properties. We propose the REMO solution, namely Resource Efficient distributed Monitoring, to reduce the overall network resource consumption incurred by both types of data, via jointly considering the locations of the packet monitors, the selection of devices forking the data packets, and flow path scheduling strategies. In the second contribution of this thesis, we investigate the resource efficiency problem in hybrid, server-centric data center networks equipped with both traditional wired connections (e.g., InfiniBand or Ethernet) and advanced high-data-rate wireless links (e.g., directional 60GHz wireless technology). The configuration space of hybrid SDN equipped with both wired and wireless communication technologies is massively large due to the complexity brought by the device heterogeneity. To tackle this problem, we present the ECAS framework to reduce the power consumption and maintain the network performance. The approaches based on the optimization models and heuristic algorithms are considered as the traditional way to reduce the operation and facility resource consumption in SDN. These approaches are either difficult to directly solve or specific for a particular problem space. As the third contribution of this thesis, we investigates the approach of using Deep Reinforcement Learning (DRL) to improve the adaptivity of the management modules for network resource and data flow scheduling. The goal of the DRL agent in the SDN network is to reduce the power consumption of SDN networks without severely degrading the network performance. The fourth contribution of this thesis is a protection mechanism based upon flow rate limiting to mitigate abusive usage of the SDN control plane resource. Due to the centralized architecture of SDN and its handling mechanism for new data flows, the network controller can be the failure point due to the crafted cyber-attacks, especially the Control-Plane- Saturation (CPS) attack. We proposes an In-Network Flow mAnagement Scheme (INFAS) to effectively reduce the generation of malicious control packets depending on the parameters configured for the proposed mitigation algorithm. In summary, the contributions of this thesis address various unique challenges to construct resource-efficient and secure SDN. This is achieved by designing and implementing novel and intelligent models and algorithms to configure networks and perform network traffic engineering, in the protected centralized network controller