Like traditional Pac Files, SmartPac also helps determine what traffic is to be diverted to the proxy servers but does it smartly. This means that it diverts traffic to Securly's proxy servers depending upon the need for in-depth analysis of a particular site for student safety.
The way SmartPac works, whenever a user sends a request it checks if the filtering policy for that user is cached. If it is not, then it would first fetch the user's policy from DNS.
If the policy is cached (or when it is fetched from the DNS), SmartPac checks if the site is allowed for that user. If it is allowed, but it is determined that it needs advanced analysis from a student safety perspective, only then is it sent to the Securly server. If the site does not require in-depth analysis, then the user is allowed to browse it and the activity is logged.
In case the filtering policy asks for the site to be blocked, then the blocked pages are sent to the cloud and the user is displayed a blocked page. However, the site is sent to the Securly server for in-depth analysis in the pursuit of student safety.