Every 15 minutes a call is being made from our um8000 to an external phone number, which I believe is a pager/beeper. Our call reporting software shows the extension dialing out as the switch extensions in our um8000. I looked everywhere in the um8000 and cannot find this particular phone number. Any ideas how this is happening and how I can stop it? Our carrier does not block individual phone numbers. I tried adding it to 21-06-05, but it caused errors when dialing other numbers.