The following URLs need to be accessible for Vision for Chromebooks to function correctly:

stun:stun.l.google.com:19302
visioncos*.netop.com (the * is a wildcard for a session ID, many users can't put wildcards in their filters so just allowing netop.com usually covers it)
 https://www.googleapis.com
 
https://accounts.google.com
 
https://accounts.google.com/accountchooser
 
https://accounts.youtube.com
 
http://www.google.com/favicon.ico

 

Note: These are not all URLs you can go to, some of them are just there to give access to the protocols needed at a given URL.