What Is RTSP?

Date First Published: 13th May 2022

Topic: Computer Networking

Subtopic: Internet Protocols

Article Type: Computer Terms & Definitions

Difficulty Level: 7/10

Learn more about what RTSP is in this article.

Not to be confused with RTP (Real-Time Transport Protocol)

Short for Real-Time Streaming Protocol, RTSP is a protocol used for controlling the delivery of real-time streaming media over the internet, such as audio and video. It was defined in RFC 2326 in 1998 and works by transferring real-time data to a device by direct communication with the server. RTSP is extensible, meaning that it can be extended or customised from its original state in order to make it appropriate for the tasks that need to be performed with it. This protocol was designed to allow users to play video and audio directly from the internet without having to download large media files to their devices.

Even though RTSP and RTP look very similar, these two protocols perform different functions. RTP is the transport protocol used for delivering live media over the internet and RTSP allows users to control the streaming of media over RTP.

Note:

RTSP does not actually stream the content itself. It communicates with the server that is streaming the data. An example of the use of RTSP is when a user pauses the video that they are streaming. RTSP will transfer the user’s request to pause the video to the server.

History

RTSP was introduced by Columbia University, Netscape, and RealNetworks. In October 1996, the first draft was sent to the IETF by Netscape and Progressive Networks. Afterwards, Henning Schulzrinne from Columbia University sent RTSP prime in December 1996. These two drafts were merged together for standardisation by the MMUSIC WG (Multiparty Multimedia Session Control Working Group) of the IETF. Additional drafts were published by the working group.

RTSP 2.0 replaced RTSP 1.0 in 2016 and was defined as RFC 7826. The newer version of RTSP is based on RTSP 1.0, but it does not have backwards compatibility. It still remains a proposed standard.