Digital Receptionist

Hi everybody…i’m new about astrerisk…i have a dubt…i had been implementing the digital receptionist feature.
I registered the message by the *77 code and i listened it right by the *99 code.
Now i’m using asterisk on lan for internal goals but, for example, if i try to call the extension 201 (with digital receptionist activated) no message start.
If, by phone, i make the 7777 i listen correctly the message…this mean likes an external call.

How can i active the digital receptionist on LAN??

Thx