ABSTRACT
Internet was born in the traditional telephone network while communication exchange can be said of the Internet natural one. Internet is now the world's largest computer Internet, it spread globally, of all sizes around the world connects to the network as a whole. In recent years, computer technology is developing rapidly, in particular the development of computer networks, increasingly profound changes in all aspects of people's lives.
This paper takes use of the class and interface of Java.net packets and Java. Sound packet, In NT 4.0 network (TCP / IP) using JDK5.0. SQL Server database developed instant communications software "I Talk." The software is divided into two parts of client and server, the client has a general communications software functions, including: point-to-point text chat function, file transfer function，instant voice communications function. The server provides new user account registration function, and the user account name login and password verification function.
Keywords: Java; I Talk; Instant communication; TCP / IP
