[How does the RealPlayer Work?]

Instructions for Downloading Real Player 5:

1. Using your World Wide Web Browser, go to the Real Networks' homepage.
   
   
2. Click on the Real Player Icon on the top left corner of the page. This will take you to another page where you can choose between downloading the free RealPlayer client, or the RealPlayer Plus, which you must pay $29.99 for.

3. The next step is to fill out the form to tell RealNetworks what kind of computer you have. You will download a specific client based on your Operating System (Windows 95, MacOS); the type of processor in your computer (Pentium, 486, PowerPC); the lan guage you want (English, Spanish, French, etc.); and your type of connecton to the Internet (14.4 kbps modem, 28.8 kbps modem, ISDN, T1 or T3). Based on the criteria you select, your computer will download the correct software for HREF="http://islab.asu.edu:80/islab/projects/bacon/newbacon/sponsors/"> ol). UDP does not "guarantee" packet delivery; instead it provides a stream of audio packets without significant delay, but at the cost of occasional lost packets. TCP is more reliable, but at the cost of what are on occasion substantial delays when the protocol "retransmits" information from the server to the client and waits for its receipt to be acknowledged. Neither method gives the user either guaranteed throughput rates or guaranteed minimum latency periods, although UDP is generally superior on both regards.

   Web Server (HTTP Protocol) as a solution

   Web Servers use the HTTP protocol, which in turn sends the information using the TCP protocols as described above. Unfortunately, when web servers are used to send time-based data such as audio that gets rapidly "consumed" by the listener, the TCP "delay" problem can really bog things down. Also, because the HTTP protocol is defined for one-way continuous transmission, it does not allow for a user-friendly implementation of such desired features as "fast forward","rewind", and "seek" to a particular part of the program. But perhaps the most significant of it all is that a Web Server approach is inefficient in using network bandwidth.
   Let us dwell on it a little bit more. A Web Server would typically try to send the whole file as fast as possible - whether it be a 10 second audio clip or a 2 hr program (see figure).

   Real Audio/Video as a solution

   The RealAudio/Video system and protocol support both the TCP and UDP protocols. However, in the vast majority of the cases the results are much better when the audio is delivered via UDP, which results in a continuous presentation a very high percentage of the time. The user clicks on these links and after a extremely small delay (basically the time taken for the first couple of packets to reach the clieEF="/concerto/performers/">
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