The Design And Realization Of Services About IM/Presence In SIPSYS System

With the development of Networks and telecommunications, VoIP (Voice over Internet Protocol) is becoming one of the key operations in NGN (Next Generation Network) technology. It brings more value-added business model for industry and more interest for users. One of the most important thing are instant communication services. It's core is IM/Presence technology . Users use voice communication, but also use the instant messages for written communication, and the Presence services for accessing to each other's situation, geographical location, communication media and other information. In the world,a number of different VoIP networks have been deployed, how to achieve the exchange is the serious problem.Currently, there are two main IM/Presence technical standards : SIMPLE and XMPP. The paper compared two agreement's advantages and disadvantages, and under the subject's background (this topic is based on SIPSYS VoIP system, which is completely follow SIP protocol), and chosed the SIMPLE protocol,detailed research and analysed SIMPLE standard files and related draft files,and in accordance with the standard designed IM servers and Presence server.Users can communicate each other with character words.The Server will store the unreachable message.And Users can have a buddy list,which show they friend's presence information.Meanwhile the list stored in the server.with the design coded and debugged the system, and finally completed functional requirements.The system conforms to SIMPLE agreement.It can intercommunicate with other standard IM/Presence systems.The First chapter introduced IM/Presence concept and background, second chapter further introduced present situation and the standard.The hird,fourth chapter discussed system demand, the design and the realization, the fifth chapter has produced the system working effect chart and the test result, and finally is drawing the conclusion.