The Design And Implementation Of A P2P-based Instant Messaging System

In recent years, there has been a lot of network-based instant messaging software,which brings convenience to people, it also makes them a mainstream networkapplications. Some of the more traditional instant messaging system is mostly used by C/S model. It will cause the server to be overwhelmed, and high maintenance costs and poorscalability of servers throughout the system. Peer (Peer to Peer, referred to as P2P)network architecture is distributed, this structure makes it strong self-adaptability.According to the characteristics of P2P networks, combine the existing traditional instantmessaging technology and P2P technologies can solve the short board of original instantmessaging software.In modern popular instant messaging software, such as QQ and MSN are based onsocial acquaintances and designed products are strong social relationships instantmessaging software. The design of a real-time communication system based on P2Ptechnology was proposed, compared with the current popular QQ and MSN instantmessaging software, the system is functionally weak social relationships emphasize thatthere is no concept of the buddy list, just add a particular P2P networks users in thisparticular P2P networks can be a group chat, private chat, file sharing, etc., and may atany time withdraw from the P2P network.The system uses a structured P2P network topology of the network. Makes findingnodes in the system even more high efficiency. In addition, in order to solve the IPv4network address depletion problem, there are many NAT devices appearing to alleviatethis problem. In order to make the users behind a NAT device node visible outside, thesystem is also designed and implemented a type of NAT detection and NAT Traversefunction.