RESEARCH AND DESIGN OF COLOR RING BACK TONE SERVICE UNDER SIP CONTROL
Zhao Jing-ling · Journal of Beijing Technology and Business University · 2008
Color Ring Back Tone is an individually and diversely service based on caller and callee.In the paper,after analyzing the SIP call flow with early media,three color ring back tone means under SIP control: the user agent approach,the color ring back tone server approach and the media server approach are put forward and analyzed in details.