The purpose of this study is to develop a learning tool for the synchronization of communication protocol at the data link layer. Our subjects are high school students. The learning objectives of this tool is to foster understanding about asynchronous system of bit synchronization, character synchronization and error detection and correction method. In this paper, related studies about learning tools for network protocol are show. Then, tool designs of out proposals are described. Finally, we discuss the effectiveness of our hands-on tool.
