[Users] connection failed

Hi all, Anyone knows the meaning of the following errors? Anyway to solve it? Dec 9 17:16:00 ow01 ./openser[19379]: ERROR: tcp_blocking_connect: timeout (10) Dec 9 17:16:00 ow01 ./openser[19379]: ERROR: tcpconn_connect: tcp_blocking_connect failed Dec 9 17:16:00 ow01 ./openser[19379]: ERROR: tcp_send: connect failed Dec 9 17:16:00 ow01 ./openser[19379]: msg_send: ERROR: tcp_send failed Dec 9 17:16:00 ow01 ./openser[19379]: ERROR:tm:t_forward_nonack: sending request failed Dec 9 17:16:00 ow01 ./openser[19379]: ERROR:tm: _reply_light: can't generate 477 reply when a final 487 was sent out Dec 9 17:16:00 ow01 ./openser[19379]: ERROR: sl_reply_error used: Unfortunately error on sending to next hop occurred (477/SL)