Your installation site uses traditional telephones and fax machines as well as the new IP Phones. What guideline can you follow to calculate the number of possible analog conections for a SBCS installation?

A.
Use the analog telephone adapter and analog voice gateway options and count the max number of IP endpoints supported by the Cisco UC520

B.
Count the number of unused IP endpoints and subtract the total number of analog devices

C.
Count the number of analog ports provided by the installation of a telephony interface card

D.
Subtract the number of analog device telephony interface ports needed for the max number of IP endpoints supported by the Cisco UC520