[otrs] Session Management OTRS0.5Beta8

Hi Martin, I have instaled Redhat 7.3 and otrs0.5 Beta8 I have the following config.pm (See attached file: Config.pm) I have the following session.pm (See attached file: Session.pm) If I'm loged as customer or agent and I close the internet explorer, without logout, when I open another internet explorer, and look at Session Managment, I can see three sessions running, But I noticed that after some time (more or less two hours) they disappeared from that page. How does sessions works at OTRS? I want to know if sessions remain opened, won't the system become slower each time a session is opened? Thanks. Diego.