Using the RTSP protocol
You can use Real Time Streaming Protocol (RTSP) to deliver content as a 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 . You can use RTSP to stream content to computers running Windows Media Player 9 Series or Windows Media Services 9 Series. 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_name/publishing_point_name/file_name), RTSP automatically negotiates the best delivery mechanism for the content. It then directs the RTP protocol to deliver streaming content using the or using a Transmission Control Protocol (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_name/publishing_point_name/file_name). 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 attempts to connect to the stream by using one of the MMS protocols. For more information about protocol rollover, see How protocol rollover works.
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.
Notes
- When setting up for Fast Streaming, use either RTSPT or HTTP protocols to connect to the . For more information about the Fast Streaming feature, see Understanding Fast Streaming. For more information about distribution servers, see Using distribution servers.
- When using RTSPU, setting the RTP size to a small value may prevent the Windows Media server from streaming. For more information about unicast packet sizes, see How unicast works.
- If a client that supports RTSP attempts to connect to the Windows Media server using a URL that starts with mms://, the content will be streamed to the client using RTSP.
Related topics
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