extension monitoring

Hello everyone, could you help me get access to the total number of authenticated extensions? There is the Status > Registrations, but it won't work at the moment because my client needs to know how many people have registered at some point. Example: I have 10 extensions, and I need to know...

Headscratcher for you guys. One department uses the BLF functionality of the Yealinks quite extensively; they have each other's phones on the first page and use extension field as ** to pick up anyone who is getting a call. Recently, one extensions stopped appearing on the other phones as...