Research And Application Of Custom-Built Instant Messaging System

MSN, Yahoo Message, ICQ, QQ, Google Talk etc are nowadays most popular Instant Message System , But these Systems focus on the personal customers all over the world ,provide a place for these people to chat. If we want to use these IM System in business and provide a place for professional custom in same industry to negotiate or consult about the industry related information, then we found that the IM system above can not support such function. In this paper we bring a IM System come from a project we do for a business trip company, it mainly focus on Hotel, Travel, Cicerone, Tourist. And provided them travel consulting, instance chat, p2p Audio & Video chat , document transfer , group chat and so on. In this system all the customers are travel industry related, so users can easily find the services or customers they need and talk to each other.. I responsible for designing the architecture of the total system and then implement it . The latest version of the client which included all the functions above has been used in business environment.We first talk about the project's requirement and background. In Ch2 we analysis the system architecture, about the server architecture there are two design methods. For there are large user connections in the system, we decide to user the multi thread service architecture and bring out some design: â‘ divide the service into Notification Service and Switchboard Service according the RFC2778[8] to shunt the user connection flows to distributed servers, â‘¡use the random number combine with MD5 method to make sure the security of the user's data in the network. â‘¢in the establish of the P2P user connection. We use the server to exchange the P2P peer's information to bypass the firewall and NAT in different network environment.A business IM System need to make sure The Server' reliable under huge users and the client need to run steadily under different software and network environment. In ch3 we discuss the key technique in the system and choose the right method, first we delete the dead connection in the user connection pool and send query network packet timely to every connections make sure there are no half-connections in the pool .then for the origin video and audio data are large and can not transport in network directly, we import the H263 and G711 protocol to encode and decode the data to send to different peers in network.Ch4 is mainly about the system implementation and usage, we use the general APIs and lib to make sure that our client can use in different version of Windows, and we also design a client crash report module to collect the stack info and Windows information when there is a error and then send to us , we can use it to improve the performance of the systemAt last this paper sum up the features if the system and bring out the future of it. And discuss the parts that can do better.