scholarly journals Forwarding Table Entries in Software Defined Networks: Representation and Uses in Network Engineering

2021 ◽  
Author(s):  
◽  
Liang Yang
Keyword(s):  
Boolean Algebra ◽  
Network Control ◽  
Systematic Research ◽  
Software Defined Networks ◽  
Production Networks ◽  
Non Invasive ◽  
Routing Table ◽  
Network Engineering ◽  
Wide Perspective ◽  
Logical Perspective

<p>Software Defined Networking (SDN) is an emerging architecture that decouples the network control and forwarding functions. In SDN, the functionality of static configuration and routing table in a traditional network has been replaced by forwarding table entries (FTEs). Thus a systematic research on FTE to better monitor traffic and manage networking resources becomes crucial in SDN. There are already some initial works on FTE representation from mathematical/logical perspective. However, they usually concentrate on the abstraction and expression of FTE rather than the applications in real network. Based on existing research, a controller is unable to monitor networking traffic and manage networking resources from a network-wide perspective. To address these challenges, Boolean algebra is chosen and extended in this thesis to examine the relations and manipulations among FTEs together with traffic statistics. Specifically, three SDN applications: i) equivalence evaluation during FTE deployment, ii) non-invasive traffic estimation and iii) anomaly detection, have been proposed and verified with the help of Boolean algebra. All of these applications rely on the mining of the FTEs and their associated statistics, thus no overhead will be introduced to the switch's original packet forwarding functionalities. They can be easily deployed in production networks due to the non-invasive strategy as well as the feasibility and flexibility in real networking scenarios.</p>

scholarly journals Forwarding Table Entries in Software Defined Networks: Representation and Uses in Network Engineering

2021 ◽  
Author(s):  
◽  
Liang Yang
Keyword(s):  
Boolean Algebra ◽  
Network Control ◽  
Systematic Research ◽  
Software Defined Networks ◽  
Production Networks ◽  
Non Invasive ◽  
Routing Table ◽  
Network Engineering ◽  
Wide Perspective ◽  
Logical Perspective

<p>Software Defined Networking (SDN) is an emerging architecture that decouples the network control and forwarding functions. In SDN, the functionality of static configuration and routing table in a traditional network has been replaced by forwarding table entries (FTEs). Thus a systematic research on FTE to better monitor traffic and manage networking resources becomes crucial in SDN. There are already some initial works on FTE representation from mathematical/logical perspective. However, they usually concentrate on the abstraction and expression of FTE rather than the applications in real network. Based on existing research, a controller is unable to monitor networking traffic and manage networking resources from a network-wide perspective. To address these challenges, Boolean algebra is chosen and extended in this thesis to examine the relations and manipulations among FTEs together with traffic statistics. Specifically, three SDN applications: i) equivalence evaluation during FTE deployment, ii) non-invasive traffic estimation and iii) anomaly detection, have been proposed and verified with the help of Boolean algebra. All of these applications rely on the mining of the FTEs and their associated statistics, thus no overhead will be introduced to the switch's original packet forwarding functionalities. They can be easily deployed in production networks due to the non-invasive strategy as well as the feasibility and flexibility in real networking scenarios.</p>

scholarly journals Performance Evaluation of Pox Controller for Software Defined Networks

2019 ◽  
Vol 8 (9S2) ◽  
pp. 679-684
Keyword(s):  
Performance Metrics ◽  
Network Control ◽  
Network Services ◽  
Software Defined Network ◽  
Software Defined Networks ◽  
Control Plane ◽  
Data Plane ◽  
Pox Controller ◽  
New Challenges ◽  
And Control

In traditional network the coupling of data plane and control plane makes the data forwarding, processing and managing of the network hard and complex. Here each switch takes its own decision, makes the network logically decentralized. To overcome the limitations in traditional network the Engineers developed a new model network known as Software Defined Network (SDN). This network the control plane is decoupled from the data plane making it less complex. It moreover has a logically centralized approach unlike the existing network. This separation enables the network control to be directly programmable and the architecture to be abstracted for applications and network services. SDN platform provides advantages like programmability, task virtualization and easy management of the network. However, it faces new challenges towards scalability and performances. It is a must to understand and analyze the performances of SDN for implementation and deployment in live network environments. SDN working with POX is studied. This paper analyses the working of POX controller and evaluates the performance metrics of POX controller for SDN environment. The emulation is done using the Emulation software

scholarly journals Detection and Classification of Malicious Flows in Software-Defined Networks Using Data Mining Techniques

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2972
Author(s):  
Marek Amanowicz ◽  
Damian Jankowski
Keyword(s):  
Data Mining ◽  
Network Control ◽  
Flow Rule ◽  
Distributed Data ◽  
Software Defined Networks ◽  
Data Mining Techniques ◽  
Wireless Applications ◽  
Using Data ◽  
Data Centres

The increasing availability of mobile devices and applications, the progress in virtualisation technologies, and advances in the development of cloud-based distributed data centres have significantly stimulated the growing interest in the use of software-defined networks (SDNs) for both wired and wireless applications. Standards-based software abstraction between the network control plane and the underlying data forwarding plane, including both physical and virtual devices, provides an opportunity to significantly increase network security. In this paper, to secure SDNs against intruders’ actions, we propose a comprehensive system that exploits the advantages of SDNs’ native features and implements data mining to detect and classify malicious flows in the SDN data plane. The architecture of the system and its mechanisms are described, with an emphasis on flow rule generation and flow classification. The concept was verified in the SDN testbed environment that reflects typical SDN flows. The experiments confirmed that the system can be successfully implemented in SDNs to mitigate threats caused by different malicious activities of intruders. The results show that our combination of data mining techniques provides better detection and classification of malicious flows than other solutions.

Transcranial direct current stimulation and neuroplasticity genes: implications for psychiatric disorders

2015 ◽  
Vol 28 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Harleen Chhabra ◽  
Venkataram Shivakumar ◽  
Sri Mahavir Agarwal ◽  
Anushree Bose ◽  
Deepthi Venugopal ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Future Research ◽  
Systematic Research ◽  
Healthy Human ◽  
Direct Role ◽  
Direct Current Stimulation ◽  
Non Invasive ◽  
Neuronal Signalling

Background and AimTranscranial direct current stimulation (tDCS) is a non-invasive and well-tolerated brain stimulation technique with promising efficacy as an add-on treatment for schizophrenia and for several other psychiatric disorders. tDCS modulates neuroplasticity; psychiatric disorders are established to be associated with neuroplasticity abnormalities. This review presents the summary of research on potential genetic basis of neuroplasticity-modulation mechanism underlying tDCS and its implications for treating various psychiatric disorders.MethodA systematic review highlighting the genes involved in neuroplasticity and their role in psychiatric disorders was carried out. The focus was on the established genetic findings of tDCS response relationship with BDNF and COMT gene polymorphisms.ResultSynthesis of these preliminary observations suggests the potential influence of neuroplastic genes on tDCS treatment response. These include several animal models, pharmacological studies, mentally ill and healthy human subject trials.ConclusionTaking into account the rapidly unfolding understanding of tDCS and the role of synaptic plasticity disturbances in neuropsychiatric disorders, in-depth evaluation of the mechanism of action pertinent to neuroplasticity modulation with tDCS needs further systematic research. Genes such as NRG1, DISC1, as well as those linked with the glutamatergic receptor in the context of their direct role in the modulation of neuronal signalling related to neuroplasticity aberrations, are leading candidates for future research in this area. Such research studies might potentially unravel observations that might have potential translational implications in psychiatry.

scholarly journals On the latency and jitter evaluation of software defined networks

2019 ◽  
Vol 8 (4) ◽  
pp. 1507-1516
Author(s):  
Paulson Eberechukwu Numan ◽  
Kamaludin Mohamad Yusof ◽  
Muhammad Nadzir Bin Marsono ◽  
Sharifah Kamilah Syed Yusof ◽  
Mohd Husaini Bin Mohd Fauzi ◽  
...  
Keyword(s):  
Network Architecture ◽  
Software Defined Networking ◽  
Network Control ◽  
Next Generation Networks ◽  
Software Defined Networks ◽  
Next Generation ◽  
Traffic Conditions ◽  
Heterogeneous Devices

Conventional networking devices require that each is programmed with different rules to perform specific collective tasks. Next generation networks are required to be elastic, scalable and secured to connect millions of heterogeneous devices. Software defined networking (SDN) is an emerging network architecture that separates control from forwarding devices. This decoupling allows centralized network control to be done network-wide. This paper analyzes the latency and jitter of SDN against a conventional network. Through simulation, it is shown that SDN has an average three times lower jitter and latency per packet that translate to improved throughput under varying traffic conditions.

Design and Implementation of the Routing Function in the NOX Controller for Software-Defined Networks

2014 ◽  
Vol 635-637 ◽  
pp. 1540-1543
Author(s):  
Xu Zhang ◽  
Wei Gang Hou ◽  
Peng Chao Han ◽  
Lei Guo
Keyword(s):  
Control Function ◽  
Network Control ◽  
Software Defined Network ◽  
Software Defined Networks ◽  
Network Environment ◽  
Core Network ◽  
Flexible Control ◽  
Design And Implementation ◽  
The Core ◽  
Data Plane

In recent years, Software-Defined Network (SDN) and its OpenFlow-based architecture have been proposed and attracted extensive attentions from academia and industry. SDN is a novel network paradigm that decouples the network control function from the data plane by using OpenFlow technology. SDN realizes the flexible control of the network traffic, and it provides a good platform for the innovation of the applications in the core network. Thus in this paper, after introducing the SDN architecture, we construct the SDN-level network environment and implement the routing function. We deploy one controller, seven OpenFlow switches and two hosts in our SDN environment. The controller and OpenFlow switches support OpenFlow-1.0 protocol. In this network environment, we successfully implement the packet transferring from one host to the other host, and make the corresponding analysis.

scholarly journals A Brief History of Cerebellar Neurostimulation

2021 ◽  
Author(s):  
Gustavo V. Ponce ◽  
Jana Klaus ◽  
Dennis J. L. G. Schutter
Keyword(s):  
Electric Stimulation ◽  
Magnetic Stimulation ◽  
Animal Experiments ◽  
Systematic Research ◽  
Brain Functions ◽  
Non Invasive ◽  
History Of ◽  
Future Direction ◽  
Invasive Techniques ◽  
Cerebellar Stimulation

AbstractThe first attempts at using electric stimulation to study human brain functions followed the experiments of Luigi Galvani and Giovanni Aldini on animal electricity during the eighteenth century. Since then, the cerebellum has been among the areas that have been studied by invasive and non-invasive forms of electrical and magnetic stimulation. During the nineteenth century, animal experiments were conducted to map the motor-related regions of cerebellar cortex by means of direct electric stimulation. As electric stimulation research on the cerebellum moved into the twentieth century, systematic research of electric cerebellar stimulation led to a better understanding of its effects and mechanism of action. In addition, the clinical potential of cerebellar stimulation in the treatment of motor diseases started to be explored. With the introduction of transcranial electric and magnetic stimulation, cerebellar research moved to non-invasive techniques. During the twenty-first century, following on groundbreaking research that linked the cerebellum to non-motor functions, non-invasive techniques have facilitated research into different aspects of cerebellar functioning. The present review provides a brief historical account of cerebellar neurostimulation and discusses current challenges and future direction in this field of research.

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

What Have We Learned From Physiological Approaches to Characterizing Dysarthria and Other Speech Production Disorders?

2010 ◽  
Vol 20 (2) ◽  
pp. 37-46
Author(s):  
Nicole M. Etter
Keyword(s):  
Speech Production ◽  
Speech Disorders ◽  
Research Literature ◽  
Systematic Research ◽  
Physiological Measures ◽  
Validity And Reliability ◽  
Assessment Measures ◽  
Perceptual Assessment ◽  
Perceptual Characteristics ◽  
Diagnostic Resolution

Traditionally, speech-language pathologists (SLP) have been trained to develop interventions based on a select number of perceptual characteristics of speech without or through minimal use of objective instrumental and physiologic assessment measures of the underlying articulatory subsystems. While indirect physiological assumptions can be made from perceptual assessment measures, the validity and reliability of those assumptions are tenuous at best. Considering that neurological damage will result in various degrees of aberrant speech physiology, the need for physiologic assessments appears highly warranted. In this context, do existing physiological measures found in the research literature have sufficient diagnostic resolution to provide distinct and differential data within and between etiological classifications of speech disorders and versus healthy controls? The goals of this paper are (a) to describe various physiological and movement-related techniques available to objectively study various dysarthrias and speech production disorders and (b) to develop an appreciation for the need for increased systematic research to better define physiologic features of dysarthria and speech production disorders and their relation to know perceptual characteristics.

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