Solution : https://service.sap.com/sap/support/notes/663615 (SAP Service marketplace login required)
Key words : 
-> web application server -> sap web application server security, business server pages -> user concepts -> logging, open inactive terminal sessions negatively affect, bsp application system               bsp application system, -> web application server -> web applications, sap web application server 6, sap web application server, internet communication manager closes, unnecessary logon screen appears, certificate-based logon requires
Related Notes : 
       
| 663434 | SAP GUI Web request: Logon necessary for request | 
| 612670 | |
| 591347 | Web request/Web survey: Corrections start_exit | 
| 566092 | Web request: start_exit function CRM 3.1 | 
| 191908 | Collective note: HTML Viewer Control |