Real Time Streaming Protocol or Real-time transmission protocol, is a network control protocol designed to be used in video and entertainment transmissions. It is a communication protocol that allows control of streaming media servers, establishes a media control session between the client and receiver and the sender.

This protocol, for example, is used to control from a receiving client Play, Pause, REW, etc. functions of a VOD (Video On Demmand) service.

RTSP typically uses the TCP protocol as a transport.

RTSP can also use UDP as its transport protocol but it is not as reliable and secure as TCP.