[Serusers] I am newcome , I can not login in my sip server that I build(Error 503)

I　am newcome , I can not login in my sip server that I build.My OS is Debain 3.0rc ,and I have installed ser_0.8.14_i386 and ser-mysql-module_0.8.14_i386 . After setup ser , add user to datebase , I try to use firefly sip client software to login my ser .It always echo me 503 (Service Unavailable). I also try MSN messager to login my ser but also fault. I try the command serctl moni ,receive just one line [cycle #: 1; if constant make sure server lives and fifo is on] . I have no ideal about this . I also try serctl ps . 0 12565 attendant 1 12567 receiver child=0 sock=0 @ 127.0.0.1:5060 2 12568 receiver child=1 sock=0 @ 127.0.0.1:5060 3 12569 receiver child=2 sock=0 @ 127.0.0.1:5060 4 12574 receiver child=3 sock=0 @ 127.0.0.1:5060 5 12575 receiver child=4 sock=0 @ 127.0.0.1:5060 6 12576 receiver child=5 sock=0 @ 127.0.0.1:5060 7 12581 receiver child=6 sock=0 @ 127.0.0.1:5060 8 12582 receiver child=7 sock=0 @ 127.0.0.1:5060 9 12583 receiver child=0 sock=1 @ 192.168.2.1:5060 10 12587 receiver child=1 sock=1 @ 192.168.2.1:5060 11 12588 receiver child=2 sock=1 @ 192.168.2.1:5060 12 12589 receiver child=3 sock=1 @ 192.168.2.1:5060 13 12593 receiver child=4 sock=1 @ 192.168.2.1:5060 14 12594 receiver child=5 sock=1 @ 192.168.2.1:5060 15 12595 receiver child=6 sock=1 @ 192.168.2.1:5060 16 12599 receiver child=7 sock=1 @ 192.168.2.1:5060 17 12600 receiver child=0 sock=2 @ 59.114.7.201:5060 18 12601 receiver child=1 sock=2 @ 59.114.7.201:5060 19 12605 receiver child=2 sock=2 @ 59.114.7.201:5060 20 12606 receiver child=3 sock=2 @ 59.114.7.201:5060 21 12607 receiver child=4 sock=2 @ 59.114.7.201:5060 22 12611 receiver child=5 sock=2 @ 59.114.7.201:5060 23 12612 receiver child=6 sock=2 @ 59.114.7.201:5060 24 12613 receiver child=7 sock=2 @ 59.114.7.201:5060 25 12621 fifo server 26 12642 timer 27 12643 tcp receiver 28 12644 tcp receiver 29 12645 tcp receiver 30 12649 tcp receiver 31 12650 tcp receiver 32 12651 tcp receiver 33 12655 tcp receiver 34 12656 tcp receiver 35 12657 tcp main process Gateway:~# /etc/init.d/ser stop Stopping ser: ser. Gateway:~# /etc/init.d/ser start Starting ser: serListening on 127.0.0.1 [127.0.0.1]:5060 192.168.2.1 [192.168.2.1]:5060 59.114.7.201 [59.114.7.201]:5060 Aliases: 59-114-7-201.dynamic.hinet.net:5060 debian:5060 localhost:5060 localhost.localdomain:5060 Gateway:~# Anyones can help me? Thanks a lot.