Congestion Control for Multimedia Streaming over the Internet

In the past few years we have witnessed an explosive growth in the usage of streaming media applications such as Real Player, Windows Media Player, and QuickTime Player, which enable a user to start playing an audio or video stream without downloading it entirely from a remote media source. According to a recent industry study, 14.2 billion video streams were served in 2004, an 80% increase compared to 2003, and the number is forecast to reach 21 billion in 2005. Another example is that Skype that offers free phone calls over the Internet has been downloaded for more than 100 million times.

The rapid growth in the usage of streaming media over the Internet has heightened the need for a congestion control protocol suitable for streaming media. The Internet Architecture Board (IAB) has expressed concerns about the possibility of congestion collapse due to the absence of congestion control of streaming media, that "there will always be occasional periods of high demand, e.g., in the two hours after an earthquake or other disaster, and this is exactly when it is important to avoid congestion collapse."