RTSP (Real Time Streaming Protocol - RFC 2326) is a client-server multimedia presentation control protocol, designed to address the needs for efficient delivery of streamed multimedia over IP networks. It leverages existing web infrastructure (for example, inheriting authentication and PICS from HTTP) and works well both for large audiences as well as single-viewer media-on-demand. RealNetworks, Netscape Communications and Columbia University jointly developed RTSP within the MMUSIC working group of the Internet Engineering Task Force (IETF). In April, 1998, it was published as a Proposed Standard by the IETF
It uses a reliable TCP control connection that sends RTSP messages in order to get information about the stream and to exchange commands, and then where possible uses an unreliable connection such as RTP to send the actual audio and or video data.
There are several variantions of RTSP:
- RTSP 1.0
- Windows Media RTSP
- Real RTSP
- Kasenna RTSP