In the TCP/IP protocol suite, an Application Layer (Layer 7) protocol for control over the delivery of data that has real-time properties, such as audio and video and including both live data feeds and stored clips. Defined in IETF RFC 2326 (1998), RTSP is intended to control multiple data sessions, provide a means for choosing delivery channels such as the User Datagram Protocol (UDP), multicast UDP, and the Transmission Control Protocol (TCP). RTSP also provides a means for choosing delivery mechanisms based upon the Real Time Transport Protocol (RTP). There is no notion of an RTSP connection. Rather, an RTSP server maintains a session labeled by an identifier. RTSP establishes and controls one or more time-synchronized streams of continuous media such as audio and video. It does not typically deliver the continuous streams itself, although it is possible to interleave the media stream with the RTCP control stream. RTSP can be thought of as a network remote control for multimedia servers. See also Application Layer, multicast, multimedia, protocol, protocol suite, real-time, RTP, server, session, TCP, TCP/IP, and UDP.