session cache versus gc

[noeledoran]

I would like to have people log in again if they have been inactive for a period of time. Does Session.cache_expire() represent that time or is it the session.gc.maxlifetime() or is it something else?

I have read the manual and done several searches, but am still confused on exactly what those two session configurations mean.

Also do I need to set the configuration on every new page prior to using the session_start()?

Thanks