In the Internet Protocol Suite, the Real-Time Protocol is a unidirectional end-to-end transport protocol appropriae for delay-sensitive, loss-tolerant applications such as audio or video streams. It may run over unicast or multicast networks, and is encapsulated in the User Datagram Protocol.
It is a best-effort protocol that does not use the Resource Reservation Protocol and does not guarantee quality of service. To assist in obtaining the best possible quality of service, the Real-Time Control Protocol provides minimal management information back to the transmitter.
- H Schulzrinne, S Casner, R Frederick, V Jacobson (July 2003), RTP: A Transport Protocol for Real-Time Applications, Internet Engineering Task Force, RFC3550