i made a test where user agent registered over tcp. then i killed it and made a call to it from another ua. here is what i got to syslog: Mar 9 07:48:49 localhost /usr/sbin/sip-proxy[26634]: INFO: Setting set_forward_no_connect() Mar 9 07:48:49 localhost /usr/sbin/sip-proxy[26634]: ERROR: tm [../../forward.h:169]: msg_send: ERROR: tcp_send failed Mar 9 07:48:49 localhost /usr/sbin/sip-proxy[26634]: ERROR: tm [t_fwd.c:1235]: ERROR: t_send_branch: sending request on branch 0 failed wireshark didn't show any tcp connection attempts so looks like set_forward_no_connect() works as expected. i verified this by uncommenting set_forward_no_connect() and got to syslog: Mar 9 07:56:18 localhost /usr/sbin/sip-proxy[26944]: INFO: Skipping set_forward_no_connect() Mar 9 07:56:18 localhost /usr/sbin/sip-proxy[26944]: ERROR:<core> [tcp_main.c:1914]: connect 192.98.102.10:47690 failed (RST) Connection refused Mar 9 07:56:18 localhost /usr/sbin/sip-proxy[26944]: ERROR:<core> [tcp_main.c:1925]: ERROR: tcp_send 192.98.102.10:47690: connect& send for 0xb560f1c8 failed: Connection refused (111) Mar 9 07:56:18 localhost /usr/sbin/sip-proxy[26944]: ERROR: tm [../../forward.h:169]: msg_send: ERROR: tcp_send failed Mar 9 07:56:18 localhost /usr/sbin/sip-proxy[26944]: ERROR: tm [t_fwd.c:1235]: ERROR: t_send_branch: sending request on branch 0 failed then also wireshark showed tcp syn request. so otherwise fine, i would like to get rid of the error messages at least in the first case, since there is really no error happening here.