[Freeswitch-users] Receives call From Unknown Extensions

Hi All I have a multi domain setup. We receive calls from unknown extensions (eg: 100 , 101,1000,1007 etc ).But there is no voice in it. We do not have any default extensions in the system and all default extensions removed from the system. Users are authenticated by alphanumeric (like an email username) Eg: mike@ mydomain.com and passwords are very complicated. How someone can call a user without authentication from these extensions? Please let me know how to solve this issue. Thanks Lloyd