What does an Error 104 mean?

Problem:

Solution:

The problem is that the system has detected more than one IP Phone (UA) registered with a phone number that is associated with an unlimited calling plan. Calling plans are restricted for use by only a single UA to prevent abuse. The simple solution is to make sure that you only have one UA programmed with the virtual phone number that is associated with your calling plan.

Occationally, due to power outages or UA reboots more than one registration can appear for the same UA, triggering an error 104. The old registration will eventually expire (you can check for when on your control panel.)