Abbreviated dialing
Agent features
Alert calling
Attendant
Authority code
Auto answer
Auto hold
Auto line selection
Auto transfer
Call forwarding
Call parking
Call pickup
Call transfer
Callback
Camp- on
Class-Of-Service
Conferencing
DISA
Distinctive ring
Do Not Disturb
Drop timeout
Exchange lines
External loud bell
External paging
Feature check
Feature codes
Forced Account Code
Forced call diversion
Group listen
Headset mode
Hold
Hot keypad
Hotline
Least Cost Routing
Lock / Unlock
Look-up
Messages
Music-on-hold
Mute
Names
No-ring transfer
Numbering plan
Off-hook Voice-Announce
Paging
Power-fail telephones
Private-to
Re-dialling
Reminder service
Service modes
SMDR
Tenant groups
Toll Restriction
U.C.D.
Virtual numbers

Class of service levels are assigned to users to prevent users from making unauthorised calls based on toll-restriction programming. There are eight class of service levels available. A user may have a different COS for day and night operating modes. Exchange lines may also be allocated one of eight different COSs, but in the majority of installations an exchange line COS of 0 (zero) is all that is required.

System Abbreviated numbers have a field that allows the specified abbreviated number to bypass COS and Toll Restriction settings, allowing that particular abbreviated number to be dialled from any keyset connected to the system, irrespective of that keyset's COS setting.

Note that all extensions in all service modes must have unrestricted access to 000 (triple zero emergency).