ERROR[10316]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to *:5068: Connection refused

[wnoguchi]

Asteriskのコンソールに以下のようなエラーメッセージが延々表示される。

[Aug 18 16:07:10] NOTICE[10281]: chan_sip.c:28837 sip_poke_noanswer: Peer 'Lync_Trunk' is now UNREACHABLE!  Last qualify: 0
[Aug 18 16:07:20] ERROR[10316]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:07:34] ERROR[10318]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:07:48] ERROR[10324]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:08:02] ERROR[10326]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:08:16] ERROR[10334]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:08:30] ERROR[10336]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:08:44] ERROR[10405]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:08:58] ERROR[10407]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused
[Aug 18 16:09:12] ERROR[10411]: tcptls.c:439 ast_tcptls_client_start: Unable to connect SIP socket to 192.168.1.6:5068: Connection refused

なんでだろう？