Research And Implementation On The Presence Service In Unified Communication System

With the development of network applications and unified communications technology, instant message and presence service have become one basic business of web services and many protocols, standards and specification s are feasible to the implementation. Due to the advantages of strong function, comprehensive content, reasonable structure and so on, the SIMPLE specification based on Session Itiation Protocol not only gains the active support of IETF, but also becomes the specification used by almost all IP and telecom equipment manufacturers and telecommunications service provides. As a result, the SIMPLE specification will be one of the key specifications used for presence service. Therefore, the research and implementation of technology relative to presence service and SIMPLE specification have a major role and significance.In this thesis, the presence service in unified communication system is explored and investigated based on the analysis of protocols relative to SIMPLE specification. The main results are as follows:1. The technology of uniform communications and memory database and the protocols of RFC3261, RFC3265, RFC3903 and RFC3863 are studied in detail.2. From the point of view application, the characteristics of presence and the requirement for corresponding terminal equipment are discussed. Meanwhile, the requirement and process of present service are investigated.3. Design and implement a presence service server. The realization of subscribe state machine, database, subscribe request messages, basic business process and presence service for across user is analized and described. Besides, the memory database table and its operation are researched and implemnted, which are able to affect the performance of present service remarkablely.4. Complete the test of the designed presence service server and the relevant test results verify the feasibility of using the server in actual unified communication system.