I'm using a UC560 and 20 508G phones. My users are getting complaints from outside callers that their extensions are busy. Callers have no problem reaching the auto attendent, but when they dial a user's extension, they get a normal busy signal. When this happens, I can call the extension internally and also get a busy signal. If I call a few times, eventually it will start ringing normally.The user is never on the phone when this happens. Any ideas why a phone that's not in use would give a busy signal and how can I stop this?
Thanks for your help!