[Users] timer question

Hi! What should happen if the invite_timer expires and there is no failure route defined? In my case happens nothing, the phone is still ringing. Shouldn't openser (CVS) cancel the call and responds with 408? If I define a failure_route, everything works fine. regards, klaus debuglog: 9(21752) DEBUG: reply relayed. buf=0x81148d0: SIP/2.0 1..., shmem=0x40606568: SIP/2.0 1 9(21752) reply_received: FR_INV_TIMER = 10 9(21752) DEBUG: add_to_tail_of_timer[1]: 0x40604d7c 9(21752) DEBUG:destroy_avp_list: destroying list (nil) 9(21752) receive_msg: cleaning up after 10 seconds: 10(21756) DEBUG: timer routine:1,tl=0x40604d7c next=(nil) 10(21756) DEBUG: final_response_handler: transaction silently dropped (0x40604c50) 10(21756) DEBUG: add_to_tail_of_timer[2]: 0x40604c98 phone is still ringing, some seconds later: 10(21756) DEBUG: timer routine:2,tl=0x40604c98 next=(nil) 10(21756) DEBUG: wait_handler : removing 0x40604c50 from table 10(21756) DEBUG: delete transaction 0x40604c50 10(21756) DEBUG: wait_handler : done phone is still ringing :-(