Using the RTSP protocol

Applies To: Windows Server 2008, Windows Server 2008 R2

You can use Real Time Streaming Protocol (RTSP) to deliver content as a unicast stream. It is an application-level protocol that was created specifically to control the delivery of real-time data, such as audio and video content. It is implemented over a correction-oriented transport protocol. It supports player control actions such as stopping, pausing, rewinding, and fast-forwarding indexed Windows Media files. You can use RTSP to stream content to computers running Windows Media Player 9 Series or later or Windows Media Services 9 Series or later. RTSP is a control protocol that works in tandem with the data delivery Real Time Protocol (RTP) to provide content to clients.

If the connection URL uses RTSP (for example, rtsp://server/publishing_point/file), RTSP automatically negotiates the best delivery mechanism for the content. It then directs the RTP protocol to deliver streaming content using UDP, or using a TCP-based protocol on a network that does not support UDP.

If you want to force the server to use a specific protocol, you can identify the protocol to be used in the announcement file. The user can also specify the protocol in the content address (for example, rtspu://server/publishing_point/file). To facilitate protocol rollover, it is recommended that the URL use the generalized RTSP protocol. That way, the Player can use either the RTSPU or RTSPT protocols to connect to the stream. If the Player cannot connect to the stream successfully by using either of the RTSP protocols, it tries to connect to the stream by using the HTTP protocol.

Windows Media Services implements RTSP through the WMS RTSP Server Control Protocol plug-in. In a default installation of Windows Media Services, this plug-in is enabled and bound to TCP port 554.


When setting up distribution servers to use Fast Streaming, use either the RTSPT or HTTP protocols to connect to the origin server.
When using RTSPU for unicast streaming, setting the RTP packet size to a small value may prevent the Windows Media server from streaming.
If a client that supports RTSP tries to connect to the Windows Media server using a URL that starts with mms://, the content will be streamed to the client using RTSP.

See Also


About unicast streaming
About protocol rollover
Windows Media protocol reference