Sip can execute complex session control together with the sdp ( session description protocol ) , in the other hand , it also can carry application specific information such as instant message and presence status etc . by message body , in latter case , it is rather a transport protocol than a application one Sip與sdp (會話描述協(xié)議)一道完成復(fù)雜的會話控制,它也可通過消息體來攜帶即時消息、呈現(xiàn)服務(wù)等各類應(yīng)用層次的信息,此時其更類似于一個傳輸層協(xié)議。
Finally the software of all the modules was give . experiment in pc demonstrates this designed software can accomplish the basic function of ip phone such as creating the connection by session initiation protocol , negotiating the media by session description protocol , transporting the stream of data by rtp / udp / ip 最后在pc上進(jìn)行了實(shí)驗(yàn),結(jié)果顯示本課題所設(shè)計的軟件可以完成ip電話的功能,使用sip信令建立連接、使用sdp信息進(jìn)行媒體流協(xié)商和使用rtp / udp / ip傳輸音頻數(shù)據(jù)流。
Main research is as the following : first , this article discusses the correlative protocol such as session initiation protocol , session description protocol and real - time transport protocol , analyses the format of the message , the field for the message and the meanings of all the fields , demonstrates the hardware 主要工作如下:首先,探討了sip協(xié)議棧的相關(guān)協(xié)議,包括sip 、 sdp和rtp ,詳細(xì)地分析了各個協(xié)議所需要的字段以及各字段的具體意義和具體的消息格式;同時還論證了實(shí)現(xiàn)ip電話終端的硬件平臺。
The Session Description Protocol (SDP) is a format for describing streaming media initialization parameters. The IETF published the original specification as an IETF Proposed Standard in April 1998, and subsequently published a revised specification as an IETF Proposed Standard as RFC 4566 in July 2006.