In our office we are using the Internet line for 100 users using SQUID Proxy (without transparent proxy). The controlling of users is now done by the ipadresses added to the ACL list.

With this we are unable to see the users who are browsing on the systems scattered all around the campus.

Now we want to implement the mechanism same like ISP providers. i.e. every user in the campus will be provided a username and password and his usage will be tracked. When ever the user logs in his entire report will be shown on the front page of that authentication page. So, that by fear of this they may use the internet in a proper manner. (How much time they used the internet etc., on what site they have spent time in whole day etc.,)

So, I request you to suggest the opensource free software proxy which is having web authentication mechanism and the usage log should be recorded of users.

Radius and a captive portal? Maybe http://coova.org/