Getting random call everyday at the same time

[rogge2]

Everyday at 3pm, one of the lady's office phone will ring at exactly 3 pm. It's been going on for a few months now and she said it happens literally every day. When she answers the phone, its never anyone there. It makes me think that its some type of alarm of some type but I am not even sure where to being as far as messing with these phones. Any one have any suggestions with what might be going on here? Any help would be greatly appreciated, thanks!

[sunilkumarv]

Display on the phone will give some info about the caller, Since its happening everyday , you can even run a list trace on the station and see the caller info.


Regards
Sunil