Cisco phones are rough even with CUCM as the central server. They freeze randomly when connected to CUCM, to the point that its a pastime to walk into an office

Cisco phones are rough even with CUCM as the central server. They freeze randomly when connected to CUCM, to the point that its a pastime to walk into an office and look at the time and date shown onscreen on all the frozen Cisco phones. Note that this freezing issue primarily affects phones made in the last decade from Cisco.