## Calculating Bandwidth Required

Based on the calculations made in Establishing Performance Goals, determine the additional bandwidth required for
deploying the Application Server at your site.

Depending on the method of access (T-1 lines, ADSL, cable modem, and
so on), calculate the amount of increased bandwidth required to handle your
estimated load. For example, suppose your site uses T-1 or higher-speed T-3
lines. Given their bandwidth, estimate how many lines are needed on the network,
based on the average number of requests generated per second at your site
and the maximum peak load. Calculate these figures using a web site analysis
and monitoring tool.

##### Example 2–3 Calculation of Bandwidth Required

A single T-1 line can handle 1.544 Mbps. Therefore, a network of four
T-1 lines can handle approximately 6 Mbps of data. Assuming that the average
HTML page sent back to a client is 30 kilobytes (KB), this network of four
T-1 lines can handle the following traffic per second:

6,176,000 bits/8 bits = 772,000 bytes per second

772,000 bytes per second/30 KB = approximately 25 concurrent response
pages per second.

With traffic of 25 pages per second, this system can handle 90,000 pages
per hour (25 x 60 seconds x 60 minutes), and therefore 2,160,000 pages per
day maximum, assuming an even load throughout the day. If the maximum peak
load is greater than this, increase the bandwidth accordingly.