Chapter 15 Security Profiles : Web filter : FortiGuard Web Filtering Service : FortiGuard Web Filter usage quotas
  
FortiGuard Web Filter usage quotas
In addition to using category and classification blocks and overrides to limit user access to URLs, you can set a daily timed access quota by category, category group, or classification. Quotas allow access for a specified length of time, calculated separately for each user. Quotas are reset every day at midnight.
Users must authenticate with the FortiGate unit. The quota is applied to each user individually so the FortiGate must be able to identify each user. One way to do this is to configure a security policy using the identity based policy feature. Apply the web filter profile in which you have configured FortiGuard Web Filter and FortiGuard Web Filter quotas to such a security policy.
 
The use of FortiGuard Web Filter quotas requires that users authenticate to gain web access. The quotas are ignored if applied to a security policy in which user authentication is not required.
When a user first attempts to access a URL, they’re prompted to authenticate with the FortiGate unit. When they provide their user name and password, the FortiGate unit recognizes them, determines their quota allowances, and monitors their web use. The category and classification of each page they visit is checked and FortiGate unit adjusts the user’s remaining available quota for the category or classification.
 
Editing the web filter profile resets the quota timers for all users.