Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

MaxHadoop: An Efficient Scalable Emulation Tool to Test SDN Protocols in Emulated Hadoop Environments

AbstractThis paper presents MaxHadoop, a flexible and scalable emulation tool, which allows the efficient and accurate emulation of Hadoop environments over Software Defined Networks (SDNs). Hadoop has been designed to manage endless data-streams over networks, making it a tailored candidate to support the new class of network services belonging to Big Data. The development of Hadoop is contemporary with the evolution of networks towards the new architectures "Software Defined." To create our emulation environment, tailored to SDNs, we employ MaxiNet, given its capability of emulating large-scale SDNs. We make it possible to emulate realistic Hadoop scenarios on large-scale SDNs using low-cost commodity hardware, by resolving a few key limitations of MaxiNet through appropriate configuration settings. We validate the MaxHadoop emulator by executing two benchmarks, namely WordCount and TeraSort, to evaluate a set of Key Performance Indicators. The tests' outcomes evidence that MaxHadoop outperforms other existing emulation tools running over commodity hardware. Finally, we show the potentiality of MaxHadoop by utilizing it to perform a comparison of SDN-based network protocols

Estudio y optimización de los procedimientos de adaptación al enlace en HSDPA

[ES] La tecnología HSDPA (High Speed Downlink Packet Access) es una evolución de UMTS creada con el objetivo de aumentar la capacidad de transmisión en el enlace descendente. Su mejora se basa en la utilización de un canal compartido de comunicación gestionado de forma eficiente desde la estación base (por medio de un packet scheduler), la utilización de mecanismos de retransmisión y combinación de información avanzados (hybrid ARQ) y la posibilidad de emplear modulaciones de alto orden (16QAM y 64QAM). Las dos últimas características nombradas serían inútiles sin unos buenos procedimientos de adaptación al enlace (link adaptation) que ajustaran los parámetros de transmisión a la calidad del enlace radio. La presente tesina aborda el estudio y optimización de los mecanismos de link adaptation en HSDPA. Para tratar el problema se siguen dos estrategias. Por un lado, se estudia un link adaptation genérico con el fin de obtener conclusiones fácilmente trasladables a sistemas particulares como HSDPA. Por otro lado, se aportan soluciones a problemas específicos de HSDPA como los fallos del link adaptation con baja carga.[EN] HSDPA (High Speed Downlink Packet Access) technology is an evolved version of UMTS focused on the improvement of the downlink capacity. HSDPA enhancement is based on the efficient management of a shared channel done by the Node-B (employing a packet scheduler), the using of advanced retransmission and combination mechanisms (hybrid ARQ) and the availability of high order modulations (16QAM and 64QAM). The later characteristics would be worthless without good link adaptation procedures that adjust transmission parameters according to the radiolink quality. This thesis deals with the study and optimization of link adaptation mechanisms in HSDPA. Two strategies are followed herein. First, a generic link adaptation is studied with the aim of reaching some general conclusions and applying them to real systems as HSDPA. Besides, a more detailed study is done for HSDPA finding solutions for some specific problems as link adaptation failures with low loadMartín-Sacristán Gandía, D. (2007). Estudio y optimización de los procedimientos de adaptación al enlace en HSDPA. http://hdl.handle.net/10251/12494Archivo delegad

A Survey on Industrial Control System Testbeds and Datasets for Security Research

The increasing digitization and interconnection of legacy Industrial Control Systems (ICSs) open new vulnerability surfaces, exposing such systems to malicious attackers. Furthermore, since ICSs are often employed in critical infrastructures (e.g., nuclear plants) and manufacturing companies (e.g., chemical industries), attacks can lead to devastating physical damages. In dealing with this security requirement, the research community focuses on developing new security mechanisms such as Intrusion Detection Systems (IDSs), facilitated by leveraging modern machine learning techniques. However, these algorithms require a testing platform and a considerable amount of data to be trained and tested accurately. To satisfy this prerequisite, Academia, Industry, and Government are increasingly proposing testbed (i.e., scaled-down versions of ICSs or simulations) to test the performances of the IDSs. Furthermore, to enable researchers to cross-validate security systems (e.g., security-by-design concepts or anomaly detectors), several datasets have been collected from testbeds and shared with the community. In this paper, we provide a deep and comprehensive overview of ICSs, presenting the architecture design, the employed devices, and the security protocols implemented. We then collect, compare, and describe testbeds and datasets in the literature, highlighting key challenges and design guidelines to keep in mind in the design phases. Furthermore, we enrich our work by reporting the best performing IDS algorithms tested on every dataset to create a baseline in state of the art for this field. Finally, driven by knowledge accumulated during this survey's development, we report advice and good practices on the development, the choice, and the utilization of testbeds, datasets, and IDSs

On the assessment of cyber risks and attack surfaces in a real-time co-simulation cybersecurity testbed for inverter-based microgrids

The integration of variable distributed generations (DGs) and loads in microgrids (MGs) has made the reliance on communication systems inevitable for information exchange in both control and protection architectures to enhance the overall system reliability, resiliency and sustainability. This communication backbone in turn also exposes MGs to potential malicious cyber attacks. To study these vulnerabilities and impacts of various cyber attacks, testbeds play a crucial role in managing their complexity. This research work presents a detailed study of the development of a real-time co-simulation testbed for inverter-based MGs. It consists of a OP5700 real-time simulator, which is used to emulate both the physical and cyber layer of an AC MG in real time through HYPERSIM software; and SEL-3530 Real-Time Automation Controller (RTAC) hardware configured with ACSELERATOR RTAC SEL-5033 software. A human–machine interface (HMI) is used for local/remote monitoring and control. The creation and management of HMI is carried out in ACSELERATOR Diagram Builder SEL-5035 software. Furthermore, communication protocols such as Modbus, sampled measured values (SMVs), generic object-oriented substation event (GOOSE) and distributed network protocol 3 (DNP3) on an Ethernet-based interface were established, which map the interaction among the corresponding nodes of cyber-physical layers and also synchronizes data transmission between the systems. The testbed not only provides a real-time co-simulation environment for the validation of the control and protection algorithms but also extends to the verification of various detection and mitigation algorithms. Moreover, an attack scenario is also presented to demonstrate the ability of the testbed. Finally, challenges and future research directions are recognized and discussed

Toward Fault-Tolerant Applications on Reconfigurable Systems-on-Chip

L'abstract è presente nell'allegato / the abstract is in the attachmen