(This tool is designed to facilitate the development and debugging of network (tcp/ip). This debugging tool is inserted between the client and the server and plays the role of forwarding packets (agent). This debugging tool extracts the data packets communicated between the client and the server, and can display the contents of the data packets in text mode or hexadecimal mode. Using this debugging tool can save the debugging time of network program, and can also be used to analyze the communication protocol.)