Research And Design Of Whiteboard Application To The Network Education

To expand the space of education, we research and design a real time andinteract system applied in network from the features of the teaching------whiteboard. Whiteboard expends the teaching space, and provides a convenient method for multi-users to cooperate work and design. We can apply this system in the network meeting and using in the Internet only by modifying a little.Upon the features that the whiteboard needs frequent interact and requirement of real time of the system, we analysis many transport mechanism in the network and conclude that the multicast can improve the efficiency of communication, and begin to research the relative techniques. In this paper, the advance and problems faced using multicast are introduced, and the challenges and the main points of realization and the function to be accounted for in design are indicated.After reading a lots reference about reliable multicast, and comparing the advantages and disadvantages of existed techniques, we decide to design the system based on the reliable multicast protocol of RAMP, which is designed by the company of TASC. The RAMP has the functions of session and member management, so it can support the cooperation work well. We describe the characteristics of RAMP, the data stream and work method in detail. Also the use of the software and the construction of the software are explained in general.The system in this paper is realized using JAVA 2 techniques. JAVA is an ideal object oriented programming language, the advantages of JAVA make it a main tools to develop the network program. The important techniques applied in the system are introduced and explained in this paper, all of them include TCP/IP SOCKET, multi-thread programming, JDBC, voice programming and JSP web pages.In this paper, we analysis the application of multicast, and then put forward the whiteboard model based on both multicast and client/server. This model uses client/server mode to accomplish the function of send messages from user to server. And decreases the complexity of managing the distributed data. At the same time, the server sends the messages to all the users by multicast, applying the advantages of the multicast and saving the bandwidth and improving thecommunication efficiency.At last, we design a whiteboard system based the model using JAVA language. The database structure is introduced, the description and save of the elements and the data structure using in the system is explained in detail. Also, this paper explains the problem of serialization during transporting data over the network, and explains the data convert ion during reading data between server and users.