Introduction

Less than 10 years after its initial development, streaming has joined the mainstream of communication media. The ubiquity of the Internet led many multimedia content owners to search for a way to deliver media over an IP network. Because it is seen as the most natural way to communicate, content creators wanted to use video and audio. We only have to look at the overwhelming success of television.

The first multimedia applications just used the Internet for file transfer to the PC. Once the entire file had been downloaded, it could then be played back locally much like a CD-ROM. This is called download-and-play.

True streaming is media content that is delivered to the viewer s media player in real-time. That means that it is transferred at the same rate as it is displayed. So a 10-minute clip will take 10 minutes to download over the network. There is no intermediate storage or caching of the content between its origin and the player. The data is processed as it arrives at the player, and then discarded.

Three developments introduced this seed change in media delivery: the streaming server, advances in compression algorithms and the improvements to the last mile . Progressive Networks developed a way to control the delivery rate of a file, so that it could be transmitted in real-time. The ongoing...