Optimization Of Embedded VoIP System Structure Based On SIP And H.323

With the bloom of Internet and the development of IP technology and VoIP technology, VoIP products are now having a rising market of the telecommunication, VoIP technology becomes one of the most popular topic in computing and telecommunication field. Because of the good feature such as simpleness, flexibility and extensibility, SIP becomes one of the most important technology in VoIP and considered the key technology in the Next Generation Network technology. To provide VoIP serives, it needs to use many embedded VoIP end devices, which is small in size and low cost, including voice gateway, trunk gateway and IPPBX. The VoIP system mentioned in this paper is running on all these embeded devices, and it support both SIP and H.323.At the beginning of this thesis, I introduce the background and key technologies of VoIP, and then describe some important protocols associated with VoIP in the second part. In the third part, I discuss a new advanced VoIP software system framework. This paper focuses on the new software framework, including requirement analysis, overall design and module design. A universal call controll state machine is the keystone and difficulty of the new framework. Reference to the already existed popular call model, a universal call model based on SIP and H.323 is carried out. This article is the result of my graduate study and practice of VOIP technology,the new VOIP framework is designed by both shaozihua and me.but the coding and testing is done by myself only.