Has anyone has experience of setting up a direct connection in a school to the internet using say ADSL or fibre link to the outside world?

If so does anyone run one in their school? Can we? Judging from several sources I think I may not be able to policies for connecting to the NGFL network may make this idea a no go. Otherwise if it is allowed Firewalls and a DMZ needs to be setup plus getting an outside IP and domain?

Any thoughts?