A Cooperative Learning of Computer Networking with Portable ...

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In a computer networking laboratory, multiple computers are allocated to make computer networks on which computer network services are installed.
A Cooperative Learning of Computer Networking with Portable Laboratories Using Virtual Machine Fuh-Gwo Chen

Kuo-Yi Chen

Chin-Yang Lin

Computer Science and Information Management Department Hung Kuang University Taichung, Taiwan. [email protected] u.tw

Engineering Science Department Cheng Kung University Tainan, Taiwan [email protected]

Engineering Science Department Cheng Kung University Tainan, Taiwan [email protected]

networking laboratory without buying extra computers. Besides, we offered students a 16GB USB flash drive that stores images of created virtual machines. It means that students can have portable laboratories for their learning of computer networking anywhere and anytime. Building computer networking needs a lot of cooperative works to build computer networks and networking services. Similarly students need to cooperatively work together to complete computer networking assignments. Then we proposed that applying cooperative learning in the computer networking learning for maximizing the learning achievement. All hands-on assignments, in the learning, are cooperative based. Students need to cooperatively work to finish the assignments. In other words, an assignment has two types of jobs: individual jobs and group jobs. Each student completes her/his individual jobs and work together with other group members to complete group jobs. We have developed an online material of our computer networking curriculum. Besides, we also developed an online survey system to collect surveys’ data. In contrast to paper surveys, it saves a lot of time on sending, collecting and analyzing a survey. A survey is written in XML such that we can quickly edit a survey using a text editor or Microsoft free XML editor, XML Notepad. This work is supported by the National Science Council of Taiwan, R.O.C. under contract NSC 97-2511-S-241-003MY2. The paper is organized as follows: firstly, we briefly give the background of virtual machine, cooperative learning and learning effectiveness; secondly, the method used in the research is presented; thirdly, the current results of the work are stated; finally conclusions as well as the future works are mentioned.

Abstract --The paper shows a working project that organizes a set of jobs to improve the learning of computer networking. It uses virtual machine to create a portable laboratory on which students do hands-on exercises anywhere. It first developed an ability indicator of computer networking. Then an online curriculum material is made and available on the Internet. Students are learning the computer networking with cooperative learning with hetero grouping. Pre-attitude and achievement scales were done with our developed online survey system. The overall result will be summarized after the experimental stage of the computer networking curriculum. Keywords: Computer networking, cooperative learning, portable laboratory, virtual machine

I.

INTRODUCTION

Computer networking is the core component of the Internet infrastructure. Skilled technicians with computer networking ability are important to the computer network world. Therefore, computer networking curriculum, offered by colleges, prepares students’ skills of creating, deploying and managing of computer networking. For maximizing the achievement of learning computer networking, students need to do hands-on exercises in a laboratory that simulates a real computer networking world. In a computer networking laboratory, multiple computers are allocated to make computer networks on which computer network services are installed. For keeping statuses of networking services, those allocated computers will be occupied until a semester-long learning ends. In other words, a school needs to prepare multiple sets of dedicated computers to students for doing hands-on exercises in learning computer network. However, cost and space are usually prohibitive. Hence school educations generally lack hands-on exercises in learning computer networking. In this paper, we used a free virtual machine software, VirtualBox [1], to build a laboratory of computer networking learning with hands-on exercises. The virtual machine software provides the functionality of creating multiple virtual computers on a real computer. Thus we can use it to make multiple computers to build one or more computer networks, that is to say, a school education of computer networking can have hands-on exercises at the least cost. A general computer classroom was extended to a computer

II.

BACKGROUND

A. Virtual machine In 1972, IBM released its first virtual machine VM/370, which was a reimplementation of CP/CMS and was a part of System/370 [2]. In 1974, Popek and Goldberg summarized the formal requirements of virtual machine [3]. Now the virtual machine has two types: system virtual machine and application virtual machine. The system virtual machine provides a platform for creating computers, on which different operating systems can be installed. It enables multiple operating systems can be simultaneously run on a

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single computer. The well-known system virtual machines are VMware workstation [4], VMware workstation [4], VMware workstation [4] and Xen [5]. Another type of the virtual machine is the application virtual machine which is designed to run non-native object programs. Its examples are Java virtual machine [6], Python [7] and Common Language Runtime [8]. It offers a portable runtime environment for a specific programming language such that applications can be written once and run anywhere. The virtual machine plays an important role in the modern computer world. It is widely used in developing and testing new applications, mirroring the running system, saving the power-consuming of running computers, etc. While the virtual machine is widely used in information technology field, the system virtual machine also was used as a teaching tool for curriculums, such as security [9-12], system administration [13], computer networking [14, 15], computer concepts [16], etc. Using the system virtual machine as a teaching tool is a good way to educate computer-related concepts to students with an existed computer. However, the published works did not mention about how appropriate learning strategies were used to maximizing the learning achievement. An instructor has better to have good teaching skills and apply appropriate learning strategies in her/his teachings.

C. Learning effectiveness Learning effectiveness is an indicator of assessment and evaluation of students’ learning outcome. It also is used in assessing the quality of teaching. Gagné et al. [19] proposed five different categories of learning effectiveness: (a) intellectual skills, (b) cognitive strategies, (c) verbal information, (d) motor skills (e) attitudes. The general way to measure the learning effectiveness is taking two tests before and after a curriculum. There are similar works in [20-23]. In the research we divided all students into two groups: control group and experimental group. Students in the experimental group are taught computer networking with portable laboratories and cooperative learning method. Other students in control group are taught computer networking with lecture-based learning. Then we planned to measure the effectiveness of the proposed strategies with two steps: (a) taking pretesting and post testing on all students by the achievement scale developed in the research and (b) counting result difference of achievements between the two groups. III. METHOD The research is to develop a new teaching method for computer networking curriculum with a portable laboratory using the system virtual machine. We first constructed an ability indicator for students in a computer networking curriculum. Since networking technologies rapidly change, the computer networking skill need to be up to date. To construct an effective ability indicator, we summarized the outline of computer networking curriculums in 42 colleges in Taiwan as a basis for further developing a material of the computer networking curriculum. We applied Delphi technique [24] in consulting computer networking specialists to modify the previous result to meet the staff requirement in information technology workplace. In the meanwhile, we tested and evaluated system virtual machines for choosing the best one as our hands-on exercise platform. The works are detailed in the following.

B. Cooperative learning Cooperative learning is an innovative and effective learning strategy, which emerged in early 1900s in America and gained a significant grow during middle 1970s and middle 1980s. It groups students into hetero groups. The size of cooperative-learning groups is about four to five students. A group is identified a specific goal. Students need to help each other because the group goal can be achieved only if each member completes the learning material or makes a specific contribution to the group's effort. Students are taught how to help one another to assist one another to overcome problems and complete tasks assigned. Topping and Ehly [17] thought that peer assisted learning (cooperative learning) is to improve learning behavior, learning effect and social skills with various types of learning, including cooperation, teaching, observation, supervision, evaluation, feedback among peers. Slavin [18] studied differences between cooperative learning and individual learning. Cooperative learning is sixty-four percent of ninety-nine observations better than individual learning while individual learning is five percent better. After the literal survey, we set a hypothesis of applying cooperative learning in learning computer networking will improve the effectiveness of learning computer networking. We thought that activities in computer networking are similar to activities in cooperative learning. Individual is responsible for the preparation of a computer in a computer network. The group interconnects computers by networking devices. It also is common in client/server architecture: one is responsible for the preparation of client, and one another accounts for the preparation of server. Therefore, we decided to set a series of works to start the improving process of computer networking learning with cooperative learning.

A. Surveying outlines of existed computer networking curriculums We chose colleges that have a computer science department as candidate colleges for surveying outlines of their computer networking curriculums. We used the Taiwan college rank [25] of Taiwan Assessment and Evaluation Association to select the first grade of ranked colleges for collecting the outlines. The number of the selected colleges is 34. We listed all topics of surveyed outlines and used their occurrence frequency to get a set of general topics in computer networking curriculums. B. Consulting computer networking specialists with Delphi method We collected comments and ability of our computer networking curriculum from computer networking specialists using an open survey. We used ground theory to extract consistent comments as a basis of developing the curriculum. Therefore, an ability of computer networking learning based

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on comments of invited specialists was retrieved. It needs multiple rounds of getting comments from the specialists until all the comment is consistent. Finally, we got an ability indicator of computer networking as a basis for further developing the curriculum material. C. Creating a portable laboratory We used VirtualBox as the platform for building a portable laboratory which provides hands-on exercises of computer networking learning. VirtualBox is open source software and is free for us to build laboratories of computer networking using existed computers. A laboratory consists of a standalone computer network and two interconnected computer networks. The networking diagram of a computer network and two interconnected computer networks are shown in Figure 1 and Figure 2, respectively. The laboratory of computer networking needs Windows XP operating systems professional edition and Linux operating system. Windows XP professional edition can act as a client as well as a server. Linux IPCop [26] provides a quick installation of network router and network firewall. Especially image files created by VirtualBox were stored on a 16GB USB flash drive such that the laboratory could be portable. It means that students can bring her/his laboratory to any computer at home or dorm. Thus students can continue hands-on exercises of computer networking outside the classroom.

Figure 2. Diagram of two interconnected computer networks

An online learning material, available at http://192.192.246.175/nscNet, has been developed according to the ability indicator. Students, in the experimental group, need to login the material system with her/his account and password to learn the material. Currently students are learning computer networking with cooperative learning. All students are hetero-grouped. Cooperative tasks in the computer networking curriculum are identified. A student group is divided into two subgroups. Each subgroup accounts for a standalone computer network and works together with another subgroup to interconnect two computer networks. In the client/server model, each subgroup also implements network services which are waited for incoming client requests issued by another subgroup. A computer networking laboratory is created to provide students a hands-on exercises’ platform. There are two kinds of operating systems in the laboratory: Windows-based OS and Linux IPCop. Linux IPCop, shown in Figure 3, is used to provide functions of a router, a NAT server, a firewall, etc. Windows-based OS, shown in Figure 4, is used to act as a client computer to request services provided by Linux IPCop or Windows XP OS. Besides, we developed an online survey system to provide an easy and quick way to collect data of different scales. The online survey system is available on the Internet, http://192.192.246.175/nscScale/Main.wgx, such that all respondents would complete an online survey anywhere. The system will automatically send an email notification to the researcher as a survey is completed. All survey data is store in the SQL Server database such that we could directly retrieve and analysis the research data. Therefore surveys in the research were completed in the fastest way.

Figure 1. Digram of a standalone computer network

D. Cooperative learning of computer networking We designed a set of cooperative tasks in computer networking learning: (a) computer interconnection, (b) network drive and printer sharing, (c) remote desktop and assistant, (d) packet interception and analysis, (e) NAT server and (f) virtual Private Network. Individual jobs and group jobs are identified in the task. Students were hetero grouped into 12 groups according to the result of students’ computer networking attitude. The size of group is 4 to 6 students. IV.

RESULTS

We first developed an ability indicator of the computer networking curriculum from the results of (a) surveying outlines of existed computer networking curriculum in 34 computer science departments in Taiwan, and (b) consulting 24 field specialists with Delphi method. The number of the ability indictors is 28. The ability indicator is divided into 5 ability groups, shown in Table I.

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V.

CONCLUSION AND FUTURE WORKS

Ability Category

In the paper, we created a portable laboratory for computer networking learning using the system virtual machine software, VirtualBox. The laboratory offers a hands-on exercise platform in learning computer networking. It benefits that a school extend its existed computer classroom to a computer networking laboratory at the least cost. Students can do hands-on exercises on the portable laboratory wherever students are at home, dorm, computer classroom, etc, also at anytime. We applied cooperative learning in the computer networking learning to maximize students’ learning effectiveness. We took a series of jobs to prepare the computer networking curriculum. The jobs are (a) constructing an ability indicator of computer networking, (b) preparing an online material, (c) grouping students with hetero group, (d) pretesting students with the achievement and attitude scales developed for computer networking, (e) teaching and learning, (f) post testing students with the same scales and (g) assessing and evaluating the method proposed in the paper. In the meanwhile, the statistic data of the experimental learning is still collecting. The learning effectiveness of the method proposed in the research will be summarized after the experimental learning. The refinement of the online material is still in progressing. In the future, we are about to design and prepare a collaboration and e-learning web space for the computer networking curriculum. The results of the research will be considered to apply in other computerrelated curriculums such as information security, network firewalling, concepts of computers, etc. TABLE I.

Ability items 27. Data encryption and decryption 28. Simple network management protocol (SNMP)

Figure 3. Linux running within VirtualBox

ABITILY INDICATOR OF COMPUTER NETWORKING

Ability Category Basics of Computer networking and communication principle

Network protocol

Network planning and building

Network device

Internet application Preliminary concepts of Network security and management

Ability items 1. 2. 3. 4. 5.

Signal process Network communication Network operating system Network toplogy Network model

6. 7. 8. 9. 10. 11. 12.

LAN protocol Hardware protocol Routing protocol TCP/IP Packet analysis Network interconnection Identification and elimination of Network problems Subnetwork General network commands Networking cable test Network address translation Wre and wireless network LAN and WAN Broadband network Internet protocols and services Message and video conference Electronic commerce Internet Data center (IDC) Intruder detection and antivirus Proxy and firewall Quality of service (QoS)

13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

Figure 4. Windows XP running within VirtualBox

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