I have a couple of Circo VoIP phones (mostly 7940 and 7960) that seem to have internal only DIDs. They are configured normally but instead of displaying the entire phone number on the display, like my other phones, it only shows the four digit DID/extension. When I call the extension with the same outside prefix as my other users I either get a disconnected message or an answer from another company.
I have never ran into this but am wondering if my DIDs are configured for internal use only and someone else owns the actual external number.
Is that possible and, if so, how can I confirm and/or fix it?