FreeRadius Accounting

Hello, I'm trying to implement accounting function kind of "open access" using FreeRadius that would allow the visitors 30 minutes of low bandwith network connetivity (say 200 kps) every 72 hours. I'm using Chillispot as captive portal and Solaris9 as the OS. Please guide me. Has someone implemented similar kind of scenario or any suggestions ?? Thanks for your time and replies. Regards. --------------------------------- Brings words and photos together (easily) with PhotoMail - it's free and works with Yahoo! Mail.