If the CBX provides any features which allow subscriber stations and
attendant's consoles to monitor the audio or data at other stations
(such as line or trunk verification or executive override), positive
barriers are placed into the system to prevent implementing these
features from outside the PCZ.
Central dictation features are disabled.
There is no CBX accessed central loudspeaker paging system.
All attendant's consoles are located within the PCZ.
Number of central answering positions is minimized.
Except for attendant's consoles, telephones are single line 2500 type.
The CBX does not maintain call detail recording information (beyond the
temporary storage that is necessary to support the communications
switching functions and auxiliary features) unless positive barriers
exist to preclude access to this information from outside the PCZ.
The CBX does not maintain speed calling lists.
The CBX and all critical station equipment are powered from
uninterruptible power supplies.
Service provided to facilities located outside the PCZ can be curtailed
to provide priority service to internal communications.
All switching, maintenance, or operational conditions set up from
subscriber stations can be selectively cancelled by an attendant's
console located within the PCZ.