Networking Bible

Chapter 25. Streaming Media

IN THIS CHAPTER

• How streaming supplies media content to users

• Streaming versus progressive downloads

• Streaming network architecture and protocols

• Unicasting versus multicasting

• Players, encoders, and streaming server software

Streaming media is a network technology that sends content to a user that can be played as it arrives. Streaming is associated with a special server called a streaming server. A related technology called progressive download can use Web servers to distribute media files.

Streaming content makes heavy use of network resources. A network architecture needs to be established to create the content, stage it to servers, and route the content to clients. All streaming solutions use a set of protocols to help package, control, and manage media traffic. The four IETF standard protocols — the Real-Time Streaming Protocol, the Real-Time Control Protocol, the Real-Time Transfer Protocol, and the SMIL markup language — are described in this chapter. The difference between unicasting and multicasting is described, and delineates different media delivery systems.

To prepare content for streaming or progressive downloads, media files need to be encoded. The process takes raw files and then compresses, segments, and packages them appropriately. Encoding can create content that has either constant or variable bit rates, as well as create a package of streams in multiple bit rates.

There are four main streaming media platforms in use today: Windows Media Services, ...