What is RTSP?
The Real Time Streaming Protocol (RTSP) establishes and controls media sessions through operations such as setup, play, pause, and teardown. The media itself is commonly transported separately over RTP.
How RTSP works
An RTSP client identifies a media resource, negotiates transport for one or more tracks, and controls their playback state through request-response methods. Session identifiers keep related commands tied to server state, while range and scale fields can support seeking or nondefault playback behavior. RTP and RTCP frequently carry the actual samples and reception reports, although RTSP can interleave those packets over TCP. It is most common between cameras, monitoring clients, and streaming servers rather than as a native browser delivery format.
Key facts
- 1RTSP uses text-formatted requests with methods including OPTIONS, DESCRIBE, SETUP, PLAY, PAUSE, and TEARDOWN; support for a method can vary by server and resource.
- 2A DESCRIBE response commonly provides SDP describing tracks and codecs, while SETUP selects transport details for each media stream before playback begins.
- 3UDP transport minimizes head-of-line blocking but is harder through NAT and firewalls; TCP interleaving is easier to traverse but can delay later packets after loss.
When RTSP matters
Use RTSP when integrating compatible IP cameras, surveillance equipment, or media servers that require session control. Firewalls and NAT can complicate separate control and media channels, especially with UDP transport.