[SR-Users] Hangup call on leg B side

Hi , i don't know how to realize this: A --- INVITE---->proxy ----INVITE----> B <--- 200 OK ---BYE----> ---INVITE ----->C <--- 200 OK proxy <--- 200 OK -------ACK ---> -------ACK ---> When B answer the call, the proxy should immediately hang up the call and make a new invite. For user A is always the same call. I tried this : onreply_route { ################################ connect if (is_method("INVITE") && status == "200") { dlg_bye("callee"); drop(); } } But it doesn't work. When arrive 200 , the proxy drop the message to the user a , wait for a while, and then send a cancel to b (it should send a BYE, instead send a CANCEL, probably because it not have a ACK). How can I try this? Thanks