12-23-2017 10:00 AM - edited 03-17-2019 11:50 AM
There are several models registered in the CM, but only CP 6901 phones turn "unregistered" suddenly. They were working for long time. What reason caused to unregistered them?
After restart CUCM, all 6901 model phone status turned to "Unknown" except 2 of them.
Solved! Go to Solution.