Real-time Transport Protocol
RTP normally runs over User Datagram Protocol (UDP).   It is used with the RTP Control Protocol (RTCP). While RTP carries the audio and video,, RTCP monitors transmission statistics and quality of service (QoS). RTP is one of the basic technologies in the use of Voice over IP. It is often used with a signaling protocol such as the Session Initiation Protocol (SIP) which creates connections across the network.