Dear Team,
I am having 116 number of 7911 series IP Phone and Call Manager version 7.1. The IP Phones are installed at one of the branch site. The IP phone some time getting unregistered with call manager. If am restarting the IP phone, it is again working fine but after 15 or 20 minutes it is again unregistering. In call manager it is showing the error DirectoryNumberMismatch. Please give me one solution to trouble shoot this issue.
Many Thanks,
Naisamuddin Pk