Hello, I'm using ser to forward to PSTN Gatways. Before the t_relay I put the command: t_on_failure("2"); So, after a timeout ser goes to: failure_route[2] { log (1, "next gateway...\n"); if (t_check_status("408|500|503")) { if (!next_gw()) { t_reply("503", "Service not available, no more gateways"); break; } log (1, "gateway changed...\n"); } t_on_failure("2"); t_relay(); } This is working very good... if the user doesn't make a hangup. If caller hangs up, the CANCEL hits SER and the call is cleanly terminated. SER however continues to failure_route after timeout of the initial INVITE... ser sends out a new INVITE message to another PSTN-Server... and the phone rings (with nobody in the line) Many thanks for your help! Sebastian