UC500 often has two DN get hung on CP7961. These 2 Phones DN are member of an ephone hunt sequential. No tones come out of the phone and the line is busy. I tried to remove the DN but got the message: 'DN X has active call on interface 50/0/X CH1.Cannot unconfigure'. My solution is to create a new ephone-dn and change it on ephone . But some time later, DN get hung again...
I try change firmware, change IOS but I still have this issue.
IOS version: uc500-advipservicesk9-mz.124-22.T.bin
Does someone meet this issue?