Solution : https://service.sap.com/sap/support/notes/545177 (SAP Service marketplace login required)
Key words : 
wan router saprouter firewalls vpn, bc-fes-gui component, rfc532918 rfc trace generation, current/required software version, trace dev_rd connection timed, current support package, dialog box appears, frontend simply disappears, kernel patch level, relevant secondary details
Related Notes : 
       
| 545784 | FAQ: RFC-related software | 
| 532918 | RFC trace generation scenarios | 
| 500235 | Network Diagnosis with NIPING | 
| 155147 | WinNT: Connection reset by peer | 
| 65325 | Error files and trace files for Remote Function Call (RFC) |