[Serusers] Ser Register Problem

Dear All, I have the latest ser (0.8.14) on fedora 2 as the sip server ,1 Mitel sip phone and xpro soft phone as the sip phones. The problem is that either the mitel or xpro sip phones can't register in ser. I used "serctl ul show",nothing is registered. I used "sipsak -vv -s sip:6000@ip address of sipserver",it shows "SIP/2.0 404 Not Found" Then I added some log functions in ser.cfg where route locates (listed below).I found out when I used "sipsak -vv -s sip:6000@ip address of sipserver",the log functions execute first at uri==myself, then (!lookup("location")) and I can see the logs in the terminal. But when I started the phone to communicate with the ser, those logs weren't show although I did see the register request from sip phones to ser from ngrep. So my first question is when the ser.cfg is executed. When I used sipsak, I could see ser.cfg is executed. When I started the sip phone, I can't see its execution. My second question is how to find out the reason for not registering. I used the IP address for the domain name. is it right to use? Because I did the test in local area network without dns. route{ log(1,"Begin route\n"); if (!mf_process_maxfwd_header("10")) { sl_send_reply("483","Too Many Hops"); log(1,"Too many hops\n"); break; }; if ( msg:len > max_len ) { sl_send_reply("513", "Message too big"); log(1,"Message too big\n"); break; }; record_route(); log(1,"record_route\n"); # loose-route processing if (loose_route()) { t_relay(); log(1,"loose route\n"); break; }; if (uri==myself) { log(1,"in the served domain"); if (method=="REGISTER") { log(1,"do the register work"); #Uncomment this if you want to use digest authentication if (!www_authorize("Ip address of sip server", "subscriber")) { www_challenge("Ip address of sip server", "0"); log(1,"do www_challenge"); break; }; save("location"); log(1,"save in the location"); break; }; # native SIP destinations are handled using our USRLOC DB if (!lookup("location")) { sl_send_reply("404", "Not Found"); log(1,"not found in the location"); break; }; }else{ log(1,"not in the domain"); }; # forward to current uri now; use stateful forwarding; that # works reliably even if we forward from TCP to UDP if (!t_relay()) { sl_reply_error(); }; } Thanks, Yilan