Coovachilli Operation Sequence

Dear Experts,

I'm newbie in captive portal and radius technology, could any expert here advice the operation sequence for Coovachilli? I'm having doubt with with the operation flow between User<-->Access Controller<-->Radius Server<-->Portal Server... Hopefully you guys can help me on this.....Appreciate it!!!!!

Cheers and regards,
Dave

how far have you got? what

how far have you got?
what documentation have you read?