What does 'RTSP' stand for?

RTSP stands for Real-Time Streaming Protocol, an application-layer protocol used to control streaming media sessions.

RTSP lets a client communicate with a media server using commands such as DESCRIBE, SETUP, PLAY, PAUSE, and TEARDOWN. It is commonly associated with video-on-demand systems, network cameras, and other applications where a user needs interactive control over audio or video playback.

A common mistake is to assume that RTSP carries the actual video and audio itself. In many implementations, RTSP handles session control while the Real-time Transport Protocol, or RTP, transports the media packets. RTCP can provide monitoring and control information alongside RTP.

The protocol was developed by RealNetworks, Netscape, and researchers at Columbia University. Its first major specification was published as RFC 2326 in 1998. RTSP 2.0 followed in 2016 as RFC 7826, updating the protocol while remaining distinct from HTTP-based streaming systems.