RTP provides end-to-end transmission services for a number of real-time data services as applications of interactive audio and video. These services include carrier pattern identification, data packet serialization, time stamp, transmission monitoring and etc.. RTCP provides feedbacks for the data transmission quality of RTP through participants transmitting RTCP packets to each other periodically. Then the server can modify the data transmission speed and carrier patterns dynamically according to the feedbacks, as a result the transmission speed reaches its maximum. In the protocol framework we provided, RTP/RTCP is not a single protocol layer and it provides interfaces to its upper layers to fulfill real-time data transmission and control. |