Incapsula uses a burstable billing model for calculation of account traffic. This model is based on calculating the 95th percentile of bandwidth usage for billing clean traffic. This enables peaks in usage that exceed the limits of your subscription for brief periods of time. This model is quite common with transit providers and with some CDNs, although many CDNs use an alternative cumulative model, described later in this topic.
For more information: Account Bandwidth Calculation
Each plan has its own monthly bandwidth allocation, as listed below:
Every 5 minutes, our systems measure the average rate of data (in bits per second) which is transferred between your website visitors and all of your sites on the Incapsula network, in both directions (visitor<>Incapsula).
We drop the top 5% of our measurements - i.e. when your bandwidth usage was at its highest peak - and the remainder is the 95th percentile that will be considered as your bandwidth usage.
- Incapsula does not charge for data transferred between Incapsula's proxy and your servers, only traffic between visitors and the Incapsula proxy.
- Blocked traffic is not calculated as part of the 95% (blocked traffic includes blacklisted traffic, L3/4 DDoS traffic, L7 DDoS traffic, bad bots, security rules and others)
- In case the total bandwidth of your account exceeded the bandwidth allocated to your plan, you will be asked to upgrade to a plan that better suits your bandwidth usage.
The 95 percentile is presented in the Traffic Dashboard: