Hi I am testing certain UAC behavior on proxy initiated 408 response with SIP Router. Call canceling is working fine - UAC gets 408 and GW gets CANCEL. However this error message is seen in syslog after fr_inv_timeout fires: BUG: tm [t_msgbuilder.c:351]: unhandled reason cause -18344 In script I set t_set_fr before t_relay, otherwise it is default: route[RELAY] { if (is_method("INVITE")) { t_on_reply("REPLY_ONE"); t_on_failure("FAIL_TEST"); } t_set_fr(4000); if (!t_relay()) { sl_reply_error(); } exit; } SIP Router is self compiled from Git: sip-router 3.1.0 (i386/linux) 34d2f6 Here are TM parameters: #modparam("tm", "local_cancel_reason", "0") modparam("tm", "noisy_ctimer", 1) modparam("tm", "auto_inv_100_reason", "tryink") modparam("tm", "failure_reply_mode", 3) modparam("tm", "fr_timer", 30000) modparam("tm", "fr_inv_timer", 120000) The above error message is found in t_msgbuilder.c on #ifdef CANCEL_REASON_SUPPORT -block. Looks like I do not have compiled in support for that new feature as I get error when uncommenting local_cancel_reason tm parameter: ERROR: <core> [modparam.c:150]: set_mod_param_regex: parameter <local_cancel_reason> not found in module <tm> Is this bug as log message suggests? -- Mikko Lehto Setera