WINCE Platform Based On .NET Environment For The Development Of SIP Phone

SIP(Session Initiation Protocol) is an application layer signaling control protocol raised by IETF(Internet Engineering Task Force),modify and terminate a session joined by one or more participants.SIP is simple and flexible,it adopts distributed control mode.It doesn't concern about the session's content but only manages and controls the session itself.In addition,SIP can provide syncretic multimedia services and has good ability of expansibility, mobility and media-negotiation.Real-time Transport Protocol(Real-time Transport Protocol,or abbreviated RTP) is a network transport protocol,which is published by the IETF working group of the multimedia transmission in 1996 in RFC 1889.RTP,described in detail on the Internet audio and video transmission standard data packet formats.It is a beginning to be designed as a multicast protocol,but later used in many unicast applications.RTP protocol commonly used in the streaming media system (in conjunction with RTCP protocol),video conferencing,and a PTT (Push to Talk) system (in conjunction with H.323 or SIP),making it the IP phone industry technology base.RTP control protocol and RTCP protocol used in conjunction with, and it is built on the User Datagram Protocol.The article is based on these two protocols,described in detail in the Windows Mobile6 platform based on.Net environment,the whole process of realization of SIP phones.It's included a general functional design,interface design,detailed design and coding.Written process will focus on the call control,voice processing,voice transmission of three parts.This thesis uses C# language implementation,Call Control part completed with SIP protocol,multi-threading technology,Events and Delegates,including calls,call tips,call ringing tips,call pick listening,the user registration,cancellation,telephone number query functions.In the voice and data transmission,achieved the open source JRTP library porting and re-packaging on WINCE platform,resolved.Net platform call unmanaged code implementation details,achieved.Net platform for voice data collection,play,coding processing and the use of RTP protocol voice data transmission.