Real-Time Transport Protocol (RTP)
RTP is a protocol that defines how devices on an IP network transmit and receive real-time media, such as VoIP systems and IP-based videoconferencing systems. RTP is defined in RFC 3550 and "profiles", which specify how to packetize various audio and video codecs used in an RTP session, are defined in RFC 3551.
RTP is used as the means to transmit audio, video, and text information within H.323, SIP, H.248, and MGCP.