i have a 7931 handset connected to my uc520 which I forward all calls to my mobile when I leave the office. This works well, however randomly at times I receive a call on my mobile from the uc520 that is silent. The call appears to originate from the uc520 however when I check the call logs (cue history) it does not show any calls during the time I received the ghost call (shows calls before and after so I know the history is working).
Can anyone suggest any ways to diagnose what is going on? I can only think of setting up a debug but as this only happens a few times a week I'm not sure I can keep the debug open that long.
Thanks for any help