Calculating Internet Server Bandwidth Requirement

As part of our Portal Management solutions, we are asked to do server sizing for many of the projects. We work with ISPs & Hardware partners in calculating the precise configuration. In the early Internet days this was purely a “guessing” game. Now it has become more and more closer to a science and if the customer has worked hard in their projections, we can get it right to large extend.

A few weeks back, one of our customers came with a requirement which is worth sharing here.

The Portal was expecting 30 Million Pageviews Per month – this was arrived by taking 10 Million Unique Users and Average PVs (Page Views) per user per month of 3. Each Page (including images) is expected to be roughly about 100KB (KiloBytes). Using this our monthly data transfer works out to 3000GB (per month). You may want to add 20-30% buffer and make this as 4000GB per month. Next comes the question of the dedicated pipe that you need for doing this data transfer per month. ISP’s generally recommend a 1.5Mbps pipe for every 175GB/month. At this rate we will require about 34Mbps pipe to do the 4000GB/Month traffic.

I cross-checked this calculation with my ISP who said a rule of thumb they follow is 3x of the average will be the peak bandwidth requirement. So how do I calculate the average bandwidth requirement for 4000GB/Month. Answer is simply to key this in Google “What is 4000 GB/month in Mb/s?”, we get 12.4Mb/s as result. Three times of this average is 37.2Mbps, which is near to our initial estimate of 34Mbps.