I think the idle user timeout is not my solution, it looks like this setting is for defining the time how long a user can idle on the GUI or SSH before he will be automaticly disconnected.
I will describe my quiestion again, sry.
1. I create a voucher for User A (username and password) he will be able to use the guest_wifi for 1 year.
2. User A connect to the guest_wifi and will be forwarded to the captive portal where he can use the provided voucher with username and password to get access to the internet.
3. User A need access for one year, he`s in office every monday and thusday. I don`t want him to logon on the captive portal every day.
Example: User A arrived the office on monday, he connect to guest_wifi and enter his username and password, so he can work online.
One day later, he is back in the office and want to access the guest_wifi again BUT NOW WITHOUT ENTERING USERNAME AND PASSWORD. This is what i mean, i will define a time range like 48 hours or so, to keep User A`s machine authenticated.
I hope this describtion is better.