what u asking i NOT recomended to do that way becuase of some internal reasons. i can give u other solution. it is posible to organize dialplan such way: allow guest sip access, then setup auth and all other in dialplan. that way wil work if u need it to auth incming calls. outgoing calls (to 1001) is posible via special dialplan(if needed), registration is not posible. escrow to start