Real Time Streaming Protocol (RTSP)

What is Real Time Streaming Protocol (RTSP)?

Real Time Streaming Protocol (RTSP) is a network control protocol designed for use in entertainment and communication systems to control streaming media servers. The protocol is used to establish and control media sessions between endpoints, and it can support the transmission of video, audio, and other types of data.

RTSP is similar to HTTP, but it is specifically designed for the control of streaming media. It allows a client to issue commands to a server, such as "play," "pause," and "record," and it can also be used to negotiate the delivery of streaming media.

RTSP is used in a variety of applications, including internet radio, IPTV, and video-on-demand. It is supported by many media players and servers, and it is often used in conjunction with other streaming protocols, such as Real-time Transport Protocol (RTP) and Real-time Transport Control Protocol (RTCP), to deliver audio and video content over the internet.

How RTSP Works?

Here is a summary of how RTSP works −

A client (such as a media player) sends an RTSP request to a server (such as a streaming media server) to establish a media session.

The server responds with a session description, which includes information about the media being streamed, such as the media format and the transport protocol to be used.

The client and server exchange RTSP commands and responses to control the flow of the media session. Examples of RTSP commands include "play," "pause," and "record."

The server streams the media to the client using the agreed-upon transport protocol, such as Real-time Transport Protocol (RTP).

The client can issue additional RTSP commands to control the media session, such as seeking to a specific point in the media or changing the volume.

When the media session is finished, the client sends an RTSP "teardown" command to the server to terminate the session.

RTSP uses TCP (Transmission Control Protocol) as its transport protocol, which provides a reliable connection for the exchange of RTSP commands and responses. However, the actual media content is typically delivered using a separate, UDP-based (User Datagram Protocol) protocol, such as RTP. This allows for the efficient delivery of streaming media with low latency.

Why it's Important?

RTSP is important because it provides a standard way to control the streaming of media over the internet. It allows clients and servers to negotiate the delivery of media in real time, and it provides a set of commands for controlling the flow of the media session.

RTSP is widely used in a variety of applications, including internet radio, IPTV, and video-on-demand. It is supported by many media players and servers, and it is often used in conjunction with other streaming protocols, such as Real-time Transport Protocol (RTP) and Real-time Transport Control Protocol (RTCP), to deliver audio and video content over the internet.

RTSP is also important because it allows for the delivery of streaming media with low latency, which is critical for applications such as live streaming and interactive media. It enables the real-time control of media sessions, allowing users to pause, seek, and adjust the volume of the media as it is being streamed.

Overall, RTSP is an important part of the infrastructure that enables the streaming of audio and video content over the internet.

Key Components

The key components of RTSP are −

Clients − Clients are typically media players or other software that sends RTSP requests to servers in order to establish and control media sessions.

Servers − Servers are typically streaming media servers that receive RTSP requests from clients and respond with session descriptions and other information. They also stream the media to the client using the agreed-upon transport protocol.

RTSP requests and responses − RTSP uses a set of requests and responses to establish and control media sessions. Examples of RTSP requests include "SETUP," "PLAY," and "TEARDOWN," and examples of RTSP responses include "200 OK" and "404 Not Found."

Transport protocols − RTSP uses TCP (Transmission Control Protocol) as its transport protocol for the exchange of RTSP requests and responses. However, the actual media content is typically delivered using a separate, UDP-based (User Datagram Protocol) protocol, such as Real-time Transport Protocol (RTP).

Session descriptions − Session descriptions are used to communicate information about the media being streamed, such as the media format, the transport protocol to be used, and the location of the media. Session descriptions are exchanged between the client and server during the setup of a media session.

Media − The media being streamed is typically audio or video content, although RTSP can also be used to stream other types of data. The media is delivered to the client using the agreed-upon transport protocol.

History and Development

Real-Time Streaming Protocol (RTSP) was developed by the Network Working Group of the Internet Engineering Task Force (IETF) in the late 1990s. The initial version of the protocol, RTSP 1.0, was published as an IETF Request for Comments (RFC) in 1998.

RTSP was designed as a control protocol for streaming media, and it was intended to be similar to HTTP, which is used for the transfer of web pages and other types of data over the internet. RTSP was designed to allow a client to issue commands to a server, such as "play," "pause," and "record," and it was also intended to be used to negotiate the delivery of streaming media.

Since its initial release, RTSP has undergone several revisions and has been extended with additional features. RTSP 2.0, which was published as an IETF Draft in 2013, added support for extended error reporting, session resumption, and other enhancements.

RTSP is widely used in a variety of applications, including internet radio, IPTV, and video-on-demand. It is supported by many media players and servers, and it is often used in conjunction with other streaming protocols, such as Real-time Transport Protocol (RTP) and Real-time Transport Control Protocol (RTCP), to deliver audio and video content over the internet.