SERVICES

RTSP Protocol Components

This protocol as already noted is part of the application layer. Various components of hardware and software make streaming possible.

Real-time streaming works with a streaming server software package, a matching streaming client, and a RealTime Streaming Protocol (RTSP), which controls their interaction.  The content is stored as files on a streaming server and is sent to remote users a few frames at a time.  If you want to broadcast live (or almost-live) events across the Internet, you need real-time streaming.  (Ernst, 2003, p.76)

The basic components are illustrated in Figure 2: How Streaming Audio and Video Work.

Figure 2:

(Wilson, 2007, p.2)

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Streaming Process

            Wilson (2007) also explains the relationship of various protocols and the streaming media process as follows:

Streaming servers typically deliver files to you with a little help from a Web server.  First, you go to a Web page, which is stored on the Web server.  When you click the file you want to use the Web server sends a message to the streaming server, telling it which file you want.  The streaming server sends the file directly to you, bypassing the Web server.

All of this data get to where it needs to go because of sets of rules known as protocols, which govern the way data travels from one device to another.  You’ve probably heard of one protocol – HTTP deals with hypertext documents, or Web pages.  Every time you surf the Web, you’re using HTTP. 

Many protocols, such as TCP and FTP, break data into packets.  These protocols can resend lost or damaged packets, and they allow randomly ordered packets to be reassembled later.  This is convenient for downloading files and surfing the Web – if Web traffic slows down or some of your packet disappear, you’ll still get your file.  But these protocols won’t work as well for streaming media.  With streaming media, data needs to arrive quickly and with all pieces in the right order. (Wilson, 2007, p.2)