[squid-users] How to limit user traffic quota?

[GoGo net]

I am running squid 3.5 in my LAN as a proxy for surfing internet.

The proxy is shared by all users in the LAN, and every user has a username/password configured in their web browser.

Now, I want to limit user traffic quota, say every user 100GB/month. How can achieve this?

Currently, I use a script to monitor **access.log** of squid, and aggregate the traffic from log to calculate user traffic. But I am wondering what is the best practise to limit user quota? Is there a better way to limit user traffic quota?

Best wishes,

Daniel