Real-Time Streaming Protocol (RTSP) gives applications the ability to stream voice and video using standard controls such as “play” and “pause.” This protocol was developed in the late 1990s. It is a foundation for the current convergence of communications, and it’s used by QuickTime, Windows Media Player, RealPlayer, MPEG4IP, Skype, and similar applications. The multiple port and protocol nature of RTSP can make streaming audio and video difficult — and as with all IP-based telecommunications, it is susceptible to jitter, packet loss, feedback, and timeliness.