[Serusers] Need explaination on SER with Asterisk

Hi all, I'm very new to SER. Currently, I have an asterisk server running ,and am able make calls thru a conventional phone via an IAD box. Presently, I am trying to implement SER on top of asterisk. My plan is to use SER as a SIP Registrar and then route calls to asterisk. It needs to be stateful. Need some clarification on this: 1. When a call is made, (ngrep)it send an INVITE request instead of a REGISTER. why? 2. I then checked and found out that my sip user has already been stored in the "location" table even before any calls were made. Why? 3.What's the difference between "location" and "subscriber" table? Why does the if(!lookup("location")) always returns true and gives a NOT FOUND error when i can see my user in location table? Below is my ser.cfg file: route{ if (!mf_process_maxfwd_header("10")) { sl_send_reply("483","Too Many Hops"); break; }; if ( msg:len > max_len ) { sl_send_reply("513", "Message too big"); break; }; record_route(); if (loose_route()) { t_relay(); break; }; # if the request is for other domain use # UsrLoc (in case, it does not work, use the # following command # with proper names and addresses in it) if (uri==myself) { if (method=="REGISTER") { if (!www_authorize("202.171.60.3", "subscriber")) { www_challenge("202.171.60.3", "0"); break; } save("location"); break; } else { # NO registered contacts,exit now if (!lookup("location")) { sl_send_reply("404","Not Found"); break; }; } t_relay(); }; # 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(); }; } I'm sure there's something wrong with my route logic. Please help. Nikki K __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com