Could be a database issue, i've seen this on CCM4.1 where a phone is registered to CCM but doesn't have an extension configured or has an extension on button 2 but not button 1. I assume as you're able to set the max calls then there is an extension associated with the phone. Make sure that this extension is on the first available phone button.
Have you tried removing the extension from the phone and re-adding it? Failing that delete the extension entirely from the unassigned extensions list and re-create it.
If it still doesn't work delete the phone and the extension and re-create.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...
If you have 2 ISR routers, one acting as Failover, do we need to have both the same number of SRST licenses on the 2 routers?
No. You will only need the SRST licenses on the primary router. Because this feature...