Essential Assessment uses Vimeo as a host for videos within our assessments and activities.
Your school's IT team will need to whitelist the domain for Vimeo. The link is as follows: http://player.vimeo.com/
This link is where the embedded videos are served from. By whitelisting this, you will only be allowing embedded videos to be viewed. Students shouldn't be able to access or view the domain vimeo.com.
Depending on your network security, you may also be able to make a rule that allows player.vimeo.com content when it comes from essentialassessment.com.au.