From the perspective of practical engineering application, under the guidance of computer network principles, combined with some common technologies in the current network, a network chat tool based on TCP/IP is compiled, which has the functions of chat room, broadcast chat, private chat between two people, file transfer and so on. This paper mainly expounds the development of chat software, various technologies related to this chat software and the implementation of this chat tool in detail:

1. As one of the applications of computer network, chat tool has been welcomed by users, which has brought people into a virtual network world and greatly deepened the relationship between people. From simple text chat to voice chat, as well as the development of images, video chat, instant messaging and online games, the concept of chat tools has been greatly expanded, and it will be the main platform for people to communicate and entertain each other through the Internet in the future.

2. The development of this tool mainly uses network communication technology, file transfer technology and windows multithreading technology.

3. Chat software is based on TCP/IP communication, which can realize point-to-point chat, broadcast chat, one-to-many chat, voice chat and file transfer.

Chat tool can run on any machine with Windows operating system.

5. Because the system adopts c/s structure, some control messages need to be transmitted between client and client, and between client and server, so the system needs to customize some message types, which is another focus of the chat tool.

6. As an independent module, file transfer greatly expands the functions of chat tools. The original TCP/IP communication is used to transmit data, and the key is to synchronize the sending and receiving threads of both parties.