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Lesson 11 Server transfer load
Objective Calculate server transfer load.

Server Transfer Load

In addition to calculating transfer speed to determine a Web page's download time, it is equally important to calculate the transfer load.

Estimating the server's transfer load

Transfer load is the bandwidth needed to accommodate all the users expected to download Web pages from a site you have designed. To calculate how much data the server must transfer, follow the steps below:
  1. Add the sizes, in bytes, of all the components of the Web page (HTML text, images, video, audio, and JavaScript code, for example).
  2. Multiply by 8 to convert bytes to bits.
  3. Multiply by the number of hits (accesses) expected on the Web page in a specified time.
  4. Divide by the number of seconds in the specified time period (for example, 86,400 seconds per day).

For example, the components of a particular Web page add up to a total of 30K. That number equals 240K. If 100,000 visitors were expected to view the page per day, that would mean a total of 24,000,000,000 bits transferred per day. There are 86,400 seconds in a day. Dividing the bits per day by the number of seconds in a day equals 277,777 bits per second or 277Kbps MINIMUM.
Why minimum? Because it's very likely some visitors will arrive at roughly the same time, increasing bandwidth requirements during those moments. For this reason, fast Web sites operate at only about 40 percent of their maximum (peak) bandwidth capacity.
In the next lesson, you will learn about network diagnostic tools for troubleshooting.

Server Transfer Load - Exercise

Click the Exercise link below to review calculating bandwidth speeds of various pipes.
Server Transfer Load - Exercise