Controlling Session Initiation Protocol (SIP)-Established Content Delivery Channels Using the Real-Time Streaming Protocol (RTSP)

The Session Initiation Protocol (SIP) is widely used for establishing multimedia sessions, whereas the Real Time Streaming Protocol (RTSP) is used in streaming media systems. RTSP has a dual role: it establishes a media session for the delivery of streaming media as well as controls the streaming session once it has been set up. Since SIP is also used for session establishment, there exists an overlap between the functionality provided by SIP and RTSP. In this document, we describe a model adopted by ETSI TISPAN, 3GPP, and Open IPTV Forum (OIPF) in which SIP and the SDP offer/answer model are used to set up a streaming session with an RTSP control channel and one or more media delivery streams. Such a model is beneficial since it allows the reuse of current architecture and functionality (e.g., authentication, charging, and QoS) established around SIP for RTSP- based streaming. The model benefits applications such as Internet Protocol Television (IPTV). In addition to the model, the document specifies two new variants of RTSP.