 etc. C 2009 by Taylor & Francis Group, LLC SIP: Advanced Media Integration Application Signaling (SIP) Media composition (JSR 309) Mediagroup Media Network (IVR, play, mixer connection pause, record) Media server FIGURE 2.4 Media control architecture. The JSR 309 API may be structured following three main sets of functional- ities, drawn in Figure 2.4. 2.2.1.6 SIP and RTSP Synergy SIP and RTSP [10] are both related to each other, but they are independent protocols that allow initiating and controlling of stored, live, and interactive multimedia sessions in the Internet. The former is used mainly for inviting participants into a multimedia session in order to initiate, for instance, a multi-party conference. The latter is used to control playback and recording for stored continuous media, in order to offer a video-on-demand like ser- vice. However, in both scenarios, these protocols can work separately. The improvement of the IP networks in terms of bandwidth capacity and QoS, and their expansion in terms of reachability and value addition are increasing the number and variety of deployment scenarios for streaming media appli- cations. These scenarios impose new requirements on signaling protocols in order to offer more flexible and scalable applications. In this sense, cooperation between SIP and RTSP can be key in creating new collaborative applications. Due to that, their synergy expands the number of media control possibilities not available with only one of them. Currently, there is no integrated solution but there are some approaches for SIP and RTSP convergence. For instance, in [11], a proxy architecture based on collaborative session transfer is proposed and, in [12], a merged scheme is described, where the re-use of RTSP as a stream control is proposed. This control is negotiated by SIP/SDP in order to keep the compatibility with exist- ing streaming solutions. Another option is to use a gateway to translate SIP messages in RTSP and vice versa. This last scheme is described in Figure 2.5. 2.2.2 SIP Appl