The Design And Development Of IP Phone's Added-Vale Services Based On SIP Protocol

SIP is an application layer control protocol which is used to establish, modify and terminate a session has one or more participants. It can supply a better integration of telecommunication services and Internet services, break the traditional telecommunication services' transmission model, introduce rules based Internet, provide IP-based multimedia services and has a promising future. So more and more IP phone developers use SIP as the signal protocol.This article has elaborated the design and implementation of IP phone terminal software based on SIP, specially the research and development of added-vale services, as well as problems been encountered and solved during the process. Followed is the main content of this article.In the introductive part there is an introduce of the background of the subject and the author's work.In the second part, there is an introduce about some important protocols and conceptions about SIP phone, such as SIP, RTP, SDP and so on.In the third part there is an elaboration in detail about extension mechanism(SUBSCRIBE and NOTIFY )based on SIP, the mechanism of instant message and the mechanism of presence.In the fourth and fifth part there are elaborations in detail about the design ideals, flow charts, state machine of the presence service, instant message, automatic callback and voice mail, and all kinds of modules of the terminal software.And also introduced the key point of the used protocol stack-eXosip. At last there is summary of the paper and some...