Visualization Design Mode for Networking Construction and Management
Jun Zheng, Guang Jin, Xianliang Jiang, Jiangbo Qian, Zhijun Xie College of Information Science and Engineering Ningbo University Ningbo, China [email protected]
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Abstract—The networking construction and management is the core technology in computer networking designs. And the main purpose of computer networking courses is also to develop students’ practical abilities of networking construction and management. Currently computer networking designs become more practical and the networking construction and management techniques are also more abstract and virtual, which make the drawbacks of traditional theory-based networking design mode increasingly obvious. Through analyzing current situations on computer networking design, we put forward the Visualization Design Mode (VDM) for Networking Construction and Management. Through using simulation tools effectively and actively, it can achieve a theoretical and practical combination and make networking design process more intuitive and effective so as to improve students’ ability of networking construction and management. Keywords- Networking Construction and Management; Visualization Design; Network Simulation
In 21st century, computer networking technology is developing rapidly and its design also turns to be an important part among all information techniques. Network is widely used in various trade and industry fields, including electronic banking, electronic commerce, modern enterprise management, information services and so on, which are developed on the basis of computer networking systems. Thus Computer-networking-related technology, especially the computer networking construction and management design becomes more essential for various engineering research and application in the engineering education in colleges. Traditional theoretical design mode has been unable to make students comprehensively understand the design process and results of Networking Construction and Management (NCM) due to abstractness of related knowledge. Thus, how to effectively improve students’ practical abilities of NCM design deserves our in-depth exploration. II.
THE ANALYSIS ON CURRENT SITUATIONS
According to our research, we find that the NCM design is mainly taken theoretical teaching in classrooms and
so-called visualization is an expressing method to present abstract things and processes by materials with graphics, images, animations, etc .
A. Practical Design Tool In many countries a trend may be observed towards an increased use of simulators which frequently replace physical experiments . As the supporting environment for VDM, an effective simulation tool is needed to realize the visualization. We suggest that the Packet Tracer  (PT) can play the role. It is an assisted study tool released by Cisco for students to learn Cisco networking courses, which provides a network simulation environment for beginners to design, configure the network and troubleshoot networking problems. Users can directly build network topologies through the graphical user interface of PT. PT also presents the detailed implementation in the process of packets transferring in the network so that students can observe the operation of the network in real-time.
Terminal Device Design
Y Network Device Design
N Choice Medium, Connection Modify
Terminal Configuration Protocol Configuration Wrong Debug and Running Figure 2. Specific steps of VDM
B. General steps in VDM Due to the complex, abstract principles and topologies in the process of NCM design, the methods should combine with the specific contents of networking technology, analyze focus and difficulties, devise networking topologies carefully and make fully use of the virtual device and simulation environment provided by PT so as to vividly display various design process and principles. The general steps of VDM are shown in figure 1 and VD means Visualization Design.
THE CONCRETE IMPLEMENTATION OF VDM
Due to space limitations, in this paper we only take a PT example to illustrate how VDM helps students to understand and master related technical principles in NCM design. The specific steps of VDM are shown in figure 2. In figure 2 the symbol Y means the network device needs inserting some new modules to enhance its function A. VD in Networking Equipment The virtual environment of software is designed to make students better contact with the actual physical device in design process. PT provides many kinds of hardware device shown in figure 3 including routers, switches, hubs, wireless device, terminal equipments, etc, for simulations. A student can simply click an appropriate device, and determine the type of equipment. Then he should use the mouse’s left button to drag the device directly to the design area of PT as required. Thus, in the design process students can directly relate to the physical hardware device and compare different characteristics of various types of equipment, which help students to avoid out of practice at choosing the device in practice.
VD in Networking Equipment
VD in Networking Topologies
VD in Networking Configuration
VD in Networking Errors
VD in Networking Running Figure 1. General steps of VDM
Figure 3. Hardware Selection Interface of PT al PT Steps
B. VD in Networking Topologies After the selection of virtual hardware device, virtual environment of software can display the topologies to students in an image way, rather than a simple text description, which makes students’ understanding in networking topologies structure more intuitive. In figure 4 there is a networking topology instance, PC0~1 are the user
hosts, Switch0 is the switch, Router0~1are the routers and Server-PT is a server. In the visualization environment of networking topologies building, even more complex networks can be created and changes can be easily incorporated into the setup .
Figure 6. Command-line Configuration Interface
Figure 4. A Networking Topology Instance
C. VD in Networking Configuration After the finish of networking topologies, for making students configure the hardware more conveniently, PT also offers powerful virtual networking configuration interface. When the device is connected properly by communication medium, the hosts or routers need to be set. Students can directly left-click the device to set its IP address and subnet mask, and other configuration information through the graphical interface in Figure 5 and it also can be set using the command line in Figure 6. The configuration and operation in the virtual environment is extremely alike to the practice so that students can directly associate with practical application. Meanwhile, for helping students to have a better understanding of internal components of networking device, PT allows students to expand the modules of networking device according to the actual configuration requirements. As shown in Figure 7, we can select the appropriate module from MODULES and then use the mouse directly to drag it to the corresponding hardware slot for achieving function extensions. For example, we can choose a new module WIC1ENET and drag it to the hardware slot. In figure 8 it is clear that the module has been added to the hardware.
Figure 7. Physical Device View Interface
Figure 8. Adding a module to hardware
D. VD in Networking Errors Networking errors detection and elimination is an important part in NCM design. After the design of the networking configuration, PT can test the network configuration results and help students to improve their capabilities to the errors detection and elimination. In the networking design process, if it is set failure or incorrectly, the software will intelligently point out the errors and the cause of errors to students. As shown in Figure 9, if the device communication medium is connected wrong, the software will indicates you through marking red point identifications and the green means it is connected correctly. In order to further identify the cause of errors and achieve the purpose of errors visualization, students can easily test the network and modify errors in a virtual environment through a graphical interface. The testing measures are similar to the practical application. We can use the command line interface (shown in Figure 10) or web interface to test the correctness of networking design.
Figure 5. Graphical Configuration Interface
Figure 9. Errors Indication in PT Figure 11. PC0 sends data request to Router0
Figure 10. Command-line Test Interface
E. VD in Networking Running In order to help students to observe the running results and fundamentally understand the operation principles of the network, PT provides network simulation functions for visually observing the running results, which can vividly display the whole running process in an image way. We only take a PT example, in figure 4 we require students to configure Router0~1 and make two separate network communicate with each other so as to get resource sharing, and PC0 can get the web service provided by Server0. After the correct configuration in networking equipment and topologies, students can select Simulation in the PT main frame, and enter the command: http://192.168.2.3 (IP Address of Server0) in PC0’s web test interface. Then the data packets to Server0 will be traveled through Router0, Router1 and Switch0. We can observe the entire data packets transmission process from Figure 11 to 12. In figure 11 the symbol of green letters is the data request information which is being transmitted and in figure 12 the purple is the data packets information. After Server0 receive the ICMP request packets, it will return packets to PC0. At last the communication between them is established.
Figure 12. PC0 sends data packets to Router0
Through the five visualization design steps we mentioned above in this paper, we can fully achieve the overall visualization design process of NCM. The VDM enables students deeply and directly to grasp the hardware configuration and the operating principle of protocols by mutual inferring between the simulation process and mechanisms of the network protocols. And it further intensifies the students’ practical application of related NCM design. Finally, the students are very appreciative of what they learnt during the labs and to hear them tell you that they finally understand the fundamentals of networking because of this design mode is extremely gratifying. V.
THE MERITS OF VDM FOR NETWORKING MANAGEMENT AND CONSTRUCTION
Firstly, the design tool (Packet Tracer) is a free and opensource network simulation tool. The software can be used to help students to achieve the visualization of the whole design process of NCM. A general PC is able to meet the simulation requirements, while actual physical devices are needless. We can save a lot of experimental equipment fund while the test environment is better. It can be widely promoted to colleges. Secondly, simulation experiments’ process and results can be easily saved, replayed and analyzed, which is difficult to achieve in the traditional design environment. Students can build an ideal networking design environment, real-time record and observe the network information of nodes and
links and reproduce the details of some special cases at any time. Thirdly, there are already a number of PT reference books at present. And these books provide many classical networking topologies and scenarios that will help students to explore networking knowledge much deeper. Fourthly, VDM can show abstract and complex networking principles and protocols vividly to students, so that they can easily grasp the networking knowledge. At last, by means of VDM, students could compare dynamic presentation process with the abstract and complex principles. VDM makes students become the main body of teaching step and stimulates their interest and further develops their innovation abilities. VI.
CONCLUSIONS AND PROSPECTS
This paper analyzes the disadvantages in traditional design modes on NCM. And we propose a novel visualization design mode, VDM. In VDM the specific use of network simulation tools vividly show the abstract, complex networking topologies and protocols to students in NCM design and it also provides students with an effective design environment. In the future, we will continue to deeply explore relevant contents in design so as to further improve the design effects of VDM according to the feedback from students. ACKNOWLEDGMENT This research was supported in part by The Innovative Electronic and Information of Ningbo Service-oriented Key Specialities, The National High Learning Undergraduate Specialities Construction Project (Computer Science in Ningbo University), The National Natural Science Foundation of China (No.60902097, 60803021), Special Funds for Key Program of the China (No.2009ZX01039002-001-04, 2009ZX03001-016, 2009ZX03004-005), Scientific Research Fund of Zhejiang Provincial Education Department (Y200906155), Ningbo Natural Science Foundation (2009A610075, 2009610070), and Ningbo University Talent Project (BSL2008006). REFERENCES 
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