Some experiences in using virtual machines for teaching computer networks

Laboratory practice is a fundamental aspect of computer network learning. Experiments tend to be very specific, frequently demanding changes in the local network topology and privileged access to the operating system configuration. These features impose a specific and exclusive laboratory for network teaching experiments. However, it is not always possible to provide such laboratory; the reality in most institutions is to have shared laboratories, used by different students and disciplines. This problem can be alleviated by the use of virtual machines, allowing each student to build his/her own network experiment, using the appropriate topology, and thus not disturbing the other activities running in the lab. This paper presents some experiences in using virtual machines to teach advanced aspects of computer networks, such as IPSec, firewalls and network services. Also, some key points are highlighted in order to show the benefits of virtual machines for pedagogical practice.Education for the 21 st century - impact of ICT and Digital Resources ConferenceRed de Universidades con Carreras en Informática (RedUNCI

Using a Virtual Computing Laboratory to Foster Collaborative Learning for Information Security and Information Technology Education

Virtual computer laboratories have been an excellent technological solution to the problem of providing students with hands-on experimentation in information technology fields such as information security in a cost effective and secure manner. A virtual computer laboratory was utilized in this work as a collaborative environment for student learning with the goal of measuring its effect on student learning and attitudes toward laboratory assignments. Experiments were carried out utilizing specially-designed computer-based laboratory activities that included student assessments and surveys upon their completion. The experiments involved both small groups and individual students completing their respective laboratory activities and subsequent assessments/surveys. The analysis of the data collected from both versions of the activity showed that students who performed the collaborative version of the activity benefited more than students who completed it on their own with respect to their learning and attitudes towards the subject areas covered in the laboratory activities

Some experiences in using virtual machines for teaching computer networks

Laboratory practice is a fundamental aspect of computer network learning. Experiments tend to be very specific, frequently demanding changes in the local network topology and privileged access to the operating system configuration. These features impose a specific and exclusive laboratory for network teaching experiments. However, it is not always possible to provide such laboratory; the reality in most institutions is to have shared laboratories, used by different students and disciplines. This problem can be alleviated by the use of virtual machines, allowing each student to build his/her own network experiment, using the appropriate topology, and thus not disturbing the other activities running in the lab. This paper presents some experiences in using virtual machines to teach advanced aspects of computer networks, such as IPSec, firewalls and network services. Also, some key points are highlighted in order to show the benefits of virtual machines for pedagogical practice.Education for the 21 st century - impact of ICT and Digital Resources ConferenceRed de Universidades con Carreras en Informática (RedUNCI

An Exploratory Factor Analysis of Student Learning in a Collaborative Virtual Computer Laboratory

Information security is a growing part of the information technology function in an organization. Higher learning institutions generally do not provide much “hands-on” exposure to information security concepts due to costs, internal information security concerns, and a lack of worthwhile exercises that cater to students. We have created a collaborative virtual computer laboratory (CVCLAB) that seeks to leverage a large group of virtual computers together with specialized designed laboratory exercises in order to create a learning environment for information security. We studied the impact of collaborative work on student learning in controlled experiments in the CVCLAB. In this paper, we are investigating how to best utilize the virtual computers for teaching information security debating such issues as whether learning is greater when exercises are conducted in groups or as individuals. We developed a research model based on Kolb’s Experiential Learning Theory and used an exploratory factor analysis to answer the research question

Design and implementation of virtual network testbeds for routing protocols

In this project, we present the design and implementation of virtual network testbeds for studying routing changes. A virtual network testbed is a computer network that is completely created in software, while routing changes directly impact on the reliability and the reachability information of the network. We used testbeds to emulate a small and a large-scale network on a single Linux machine. These emulated networks allow the study of network behavior and operations which are examined using two routing protocols: Routing Information Protocol (RIP) and Open Shortest Path First (OSPF). We implemented a fifteen-node network to study RIP, and a model of the GÈANT network to examine OSPF in virtual network testbeds. Each testbed represents an autonomous system (AS) or an intra-domain environment. Therefore, these environments provided us with the opportunities to evaluate routing changes in an AS. We used the testbeds to compare the routing of the original network with the new routing of the missing links and routers to see what changes occur. The GÈANT network is the large-scale network used for investigations in this project. We then used our emulation results of the large-scale network to compare with the simulation work for the same network topology-the GÈANT network, and confirmed that our emulation studies also identified important links and routers in the same network. --P.ii.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b162504

Virtualisation distribuée de réseaux dynamiques et mobiles avec NEmu

International audienceExperimentation is generally the last step before launching a network application in the wild. However, it is often difficult to gather enough hardware resources, control and mobility for experimenting in order to test and validate an application. Virtualization is thus a reliable and cheap technique for creating such an experimentation testbed. We propose a tool called NEmu designed to create virtual static, dynamic or mobile networks for testing and evaluating prototypes of network applications with a complete control over the network topology, link properties and mobility behavior. NEmu allows users to create customized topologies with limited hardware resources and without any administrative rights. We illustrate the use of NEmu in the context of a file distribution application upon a TCP connections tree. We evaluate the impact of such a tree on data rates and delays depending on the number of tree nodes, packets size and general bandwidth of links.L'expérimentation est généralement la dernière phase dans l'élabora-tion d'une application réseau avant sa diffusion. Malheureusement, il est assez difficile, voir impossible, de posséder une infrastructure physique suffisamment puissante, contrôlée et dynamique de réseau fixe ou mobile afin de tester et va-lider l'application. La virtualisation est par conséquent une technique fiable et économe pour jouer le rôle de plate-forme de test. Nous proposons un outil ap-pelé NEmu ayant pour but de générer des réseaux virtuels statiques, dynamiques ou mobiles à la demande afin de tester et de valider des prototypes d'applications réseaux avec un contrôle complet de la topologie, de la mobilité des noeuds ainsi que des propriétés des liens. NEmu permet la création et la gestion de réseaux virtuels avec des ressources matérielles limitées et sans aucun droit d'accès par-ticulier. Nous proposons également une illustration de l'utilisation de NEmu afin de tester l'efficacité d'une application de distribution de fichiers reposant sur un arbre de connexions TCP. Nous mesurons ainsi l'impact d'un tel chaînage sur les débits et les délais en fonction du nombre de noeuds dans l'arbre, de la taille des paquets et de la bande passante globale des liens

Virtual machines In Education

Abstract To provide education and particularly providing practical educational experiences to the students in the field of computing and information technology related courses including practical experience in the field of Networking, System Administration, and Operating Systems needs a lot of resources for the institution. Because this level of technical education can’t be provided only theoretically, students also need hands-on practical experience, and providing practical experience faces a lot of problems such as lack of funding and physical space, risks and threats to the network environment when we attempt to provide real, physical laboratory for experiments. This problem can be solved by developing a virtual environment for delivering students practical education. In this report we will look into different technologies used for virtualization today and do a comparative study. We will also explore some of the institutions, which are using virtual machines based environment to provide students practical experience in the field of computing and information Technology. And see how peoples are getting benefits from using virtual machines. We present how networks of virtual machines can be beneficiary for computing and information technology student and institutions by providing necessary environment in virtual network

Monitoring and evaluation nivelation of tooth on 3D digital models

3D modeliranje je nova tehnologija primenjena u ortodonciji. U ovim istraţivanjima ova tehhnologija je primenjena za praćenje nivelacije zuba. Da bi se to ostvarilo, uz primenu standardnih geometrijskih modelera (CAD sistemi), za ova istraţivanja, su razvijeni referentni geometrijski entiteti (RGE), kao osnovni, izvedeni i anatomski. Na ovaj naĉin se definišu ortodontski parametri, a na novi naĉin vrše ortodontske analize, na primeru nivelacije zuba. Definisan je skup od 54 ortodontska parametra, 28 za donju vilicu i 26 za gornju vilicu. Oni se prate u prostoru, u sve tri ortodontske ravni, preko anatomskih taĉaka zuba. Definisan je konept e personalne ordinacije, razvijen model praćenja poloţaja zuba u prostoru, postavljen koncept modeliranja zubnog luka pomoću splajna u okluzalnoj ravni i istraţena taĉnost dva skenera. Sve ovo testirano je na primeru nivelacije zuba. MATERIJAL I METOD: U ovim istraţivanjima osnovni uzorak je obuhvatio 155 pacijenata, Klinike za ortopediju vilica Stomatološkog fakulteta u Beogradu. Populacija koja je saĉinjavla ovaj uzorak bila je starosti od 15 do 26. godina, oba pola. Kod svih njih sa ortodontske taĉke gledišta, javljali su se sledeći problemi: nepravilan poloţaj zuba, teskoba, malokluzija razliĉitog tipa, nepravilan oblik zubnog luka. Pratila se nivelacija zuba (njihov poloţaj u prostoru, kao i u okluzalnoj ravni), koja spada u prvu fazu terapije fiksnim aparatima. Ona obuhvata sledeće: (i) Nivelaciju bravica, odnosno regulisanje vertikalnih odstupanja pojedinih zuba, (ii) Korekcija rotiranih zuba, (iii) Korekcija labio(buko) lingvalnih odstupanja zuba, i (iv) Uspravljanje zuba. Skeniranje je vršeno na: Next Engine (Stomatološki fakultet, Beograd), Atos (Topomatika, Zagreb) i LazakSkan (Fakultet za strojništvo, Ljubljana). Dobijeni 3D modeli su obraĊeni u programu GOM Inspect V8 (V8 Hotfix 6, Rev. 81431), a ortodontske analize i sinteze su vršene na Solid Works i Siemens PLM NX10 softveru. Kao metod korišćen je prilaz generisanja 3D digitalnog modela, a na njemu, kroz konkretni primer, definisanje, merenje i praćenje RGE, koji su korišćeni za ortodontske analize i sinteze. Ova istraţivanja su zasnovana na primeni sledećih metoda: analiza (ortodontskih sluĉajeva, stanja, parametara, trendova, ...), sinteza (terapijskih metoda, procedura i postupaka, ...), indukcija (predviĊanje ortodontskih trendova za skup u odnosu na uzorak) i dedukcija (izvlaĉenje zakljuĉaka o ortodontskom stanju za svakog pacijenta posebno). Naravno, kao bazni postupak za ova istraţivanja korišćeno je 3D modeliranje, kao nauĉna disciplina koja je prvo razvijena u inţenjerstvu, a ovde će se primenjivati u ortodonciji...3D modeling is a new technology applied in orthodontics. In this research, this technique was used to evaluate teeth nivelation. In order to do this, with the application of standard geometric modelers (CAD systems), for these investigations, reference geometric entities (RGEs) have been developed, as basic, derivative and anatomical. In this way, orthodontic parameters are defined, and in a new way they perform orthodontic analysis, in the case of a tooth nivelation. A set of 54 orthodontic parameters is defined, 28 for the lower jaw and 26 for the upper jaw. They are monitored in the space, in all three orthodontic levels, through the anatomical points of the teeth. The concept of e personal practice is defined, the developed model for monitoring the position of teeth in the space, the concept of modeling the dental arch using the spline in the occlusal plane was set up and the accuracy of the two scanners was explored. All this has been tested on a case of tooth nivelation. MATERIAL AND METHODS: In these studies, the basic sample covered 155 patients, Clinics for orthodontics, Faculty of Dentistry in Belgrade. The population that made this sample was between the ages from 15 to 26, both sexes. In all of them from the orthodontic point of view, the following problems have been reported: incorrect position of teeth, disturbances, different types of malooclusions, irregular shape of the dental arch. The leveling of the teeth (their position in the area, as well as in the occlusal plane) was observed, which belongs to the first phase of therapy with fixed devices. It includes the following: (i) Leveling of brackets, ie regulation of vertical deviations of individual teeth, (ii) Correction of rotated teeth, (iii) Correction of labio (bucco) lingual tooth deviations, and (iv) Tooth decay (upright). The scan was performed at: Next Engine (Faculty of Dentistry, Belgrade), Atos (Topomatika, Zagreb) and LazakSkan (Faculty of Mechanical Engineering, Ljubljana). The obtained 3D models were processed in the GOM Inspect V8 (V8 Hotfix 6, Rev. 81431) and the orthodontic analysis and synthesis were performed on Solid Works and Siemens PLM NX10 software. As an approach, the approach of generating a 3D digital model was used, and on it, through a concrete example, the definition, measurement and monitoring of RGE, used for orthodontic analysis and synthesis. These studies are based on the application of the following methods: analysis (orthodontic cases, states, parameters, trends, ...), synthesis (therapeutic methods, procedures and procedures, ...), induction (prediction of orthodontic trends for a set versus sample) and deduction (drawing conclusions about the orthodontic condition for each patient separately). Of course, as a basic process for these research, 3D modeling, as a scientific discipline that was first developed in engineering, and here will be applied in orthodontics..

Wormulator: Simulator for Rapidly Spreading Malware

This project addresses the need for an application level simulator to simulate Internet-wide phenomenon such as flash worms, botnets, Distributed Denial-of-Service attacks, etc. There are many network simulators intended for parallel and distributed simulation, but most are designed to simulate low level communication protocols such as TCP/IP. The desire to simulate rapidly spreading malware for research and teaching purposes lead us to explore the Spamulator, which was designed to simulate spam email on an Internet-wide scale. The Spamulator was developed by a team at the University of Calgary. It is a lightweight, application level simulator, which implements limited set of features of the Internet. In this project, the Spamulator is enhanced with the User Datagram Protocol (UDP) to simulate UDP worms. The modified version of the Spamulator is called the Wormulator. Wormulator tracks instantaneous network traffic, identifies and signals congestion throughout the network. The Wormulator is further enhanced with the use of POSIX threads instead of forking processes to create a distributed network of simulated servers. The resulting tool is called the “Enhanced Wormulator”. Finally, a random scanning UDP worm with behavior similar to the well known SQL Slammer worm is modeled to validate the results of our simulation. Results and data gathered from the simulation exhibit a qualitative resemblance to the realworld SQL Slammer worm. “Enhanced Wormulator”, which uses POSIX thread instead of forking a process, had a catalytic effect on the scalability factor of the simulation. The simulation was run on a network of 30,000 server nodes. Hence, we conclude that rapidly spreading malware can be effectively simulated using the Wormulator

Brain-Based Learning Theory: An Online Course Design Model

The development of a theoretical brain-based online course design model with potential transferability across course management systems in higher education is the problem for this study. Qualitative inquiry was the emergent design and consisted of an extensive current, relevant literature review of educational literature in brain-based learning theory, online course design, and course management systems for the purpose of developing a theoretical brain-based online course design model for higher education. The model developed includes synthesized indicators from the analytical charting. The proposed model is presented in acronym form, which in and of itself aligns with brain-based learning theory. The acronym IGNITE has emerged as the theoretical brain-based model and will be discussed