We are having CUCM version 7.1.5 in our cluster. One of our Subscriber in our branch office is having around 3000 phones registered in it.
The issue we are facing right now is that the IP phones and Gateways registered in the Sub are showing "Unknown" status
They are able to call each other make calls outside too.
I have restarted the RIS Data Collector Service in the sub but the status of the phone still shows Unknown.
Any help would be appreciated