IP Phone User Manual
1.8 Toll Restriction (TRS)/Call Barring (Barring) Features
Feature Guide 105
Conditions
WARNING
The software contained in the TRS/Barring feature to allow user access to the network 
must be upgraded to recognise newly established network area codes and exchange 
codes as they are placed into service.
Failure to upgrade the premises PBXs or peripheral equipment to recognise the new 
codes as they are established will restrict the customer and the customer’s employees 
from gaining access to the network and to these codes.
KEEP THE SOFTWARE UP-TO-DATE WITH THE LATEST DATA.
• A COS should be assigned for each extension. (  Class of Service [602])
• TRS/Barring checks are applied to the following:
• It is programmable whether " " or "#" is checked by the TRS/Barring. This is useful in 
preventing unauthorised calls which could be possible through certain telephone company 
exchanges.
• It is programmable whether TRS/Barring checks the digits dialled after the External 
Feature Access during a trunk call. (  1.10.7 External Feature Access (EFA))
• Host PBX Access Code/Special Carrier Access Code
TRS/Barring checks for numbers dialled with a Host PBX Access code (  1.5.4.7 Host 
PBX Access Code (Access Code to the Telephone Company from a Host PBX)) or a 
Special Carrier Access code (  1.5.4.8 Special Carrier Access Code) in the following 
cases:
• ARS
If ARS is applied to a dialled number, TRS/Barring will check the user-dialled number (not 
the modified number by ARS). In this case, a Host PBX Access code and/or a Special 
Carrier Access code will not be checked.
• Dialling Digit Restriction during Conversation 
The dialling of digits can be restricted while engaged on a received trunk call. If the number 
of dialled digits exceeds the preprogrammed limitation, the line will be disconnected.
• A TRS/Barring level can be changed by some features. The priority of features, when 
multiple features are used, is as follows:
1) Dial Tone Transfer (  1.8.4 Dial Tone Transfer)
2) Budget Management (  1.8.2 Budget Management)
3) TRS/Barring Override by System Speed Dialling
–ARS
– Trunk Access (Idle Line/Trunk Group/S-CO Line)
Type
Stored
Not stored
Found Not found
Host PBX 
Access Code
Deletes the code. A 
TRS/Barring check is 
carried out on the 
following digits.
The call is made 
(excepted from TRS/
Barring).
TRS/Barring checks 
the whole number.
Special Carrier 
Access Code
Deletes the code. A 
TRS/Barring check is 
carried out on the 
following digits.
TRS/Barring checks 
the whole number.
TRS/Barring checks 
the whole number.










