Toll Restriction (TRS) can prohibit certain extension users from making unauthorised outside (CO) line calls. Every extension is assigned to one of 5 classes of service (COSs) for each time service mode (

TRS-COS—Day/Night/Lunch [601-603]); COS 1 grants the highest level of authorisation, allowing all outside (CO) line calls to be made, and COS 5 grants the lowest level of authorisation. COSs 2 through 5 are used to restrict calls with a combination of preprogrammed Denied and Exception Code Tables, explained below.

Denied Code Tables (

TRS—COS 2-5 Denied Code [302-305])
Denied Code Tables are preprogrammed lists containing the telephone numbers that are restricted. All outgoing outside (CO) line calls made by COS 2 through 5 users are compared to the applicable Denied Code Table(s), and when the leading number of a dialled telephone number (not including the Outside (CO) Line Access number) matches an entry found in an applicable table, the call is denied.
Up to a total of 80 denied codes, each consisting of up to 11 digits, can be stored.

Exception Code Tables (

TRS—Exception Code [306])
Exception Code Tables are preprogrammed lists of leading digits or complete telephone numbers that are checked against every dialled number prohibited by a Denied Code Table. When a dialled number is prohibited by a Denied Code Table, it is compared to the applicable Exception Code Table(s). If the dialled number matches an entry found in an applicable Exception Code Table, the call is permitted.
Up to 80 exception codes, each consisting of up to 11 digits, can be stored. The available number of codes depends on the COS assigned to each extension.

Applicable tables by COS
The Denied Code Tables and Exception Code Tables that apply to each COS are listed below.

COS No.

Denied Code Tables

Exception Code Tables

No restriction.
(Not Programmable)

20 denied codes programmed in [302].
(Table for Class 2)

80 exception codes (code numbers 01–80) programmed in [306].
(Tables for Classes 2 through 5)

40 denied codes programmed in [302] and [303].
(Tables for Classes 2 and 3)

60 exceptions codes (code numbers 01–60) programmed in [306].
(Tables for Classes 3 through 5 )

60 denied codes programmed in [302] through [304].
(Tables for Classes 2 through 4)

40 exception codes (code numbers 01–40) programmed in [306].
(Tables for Classes 4 and 5)

80 denied codes programmed in [302] through [305].
(Tables for Classes 2 through 5)

20 exception codes (code numbers 01–20) programmed in [306].
(Table for Class 5)

TRS for System Speed Dialling (

TRS—System Speed Dialling Class [301])
Calls made using System Speed Dialling are restricted depending on the COS of System Speed Dialling numbers and the COS assigned to each extension. If, for example, the COS of System Speed Dialling numbers is assigned as "2", the PBX will allow System Speed Dialling calls for the extensions with COSs 1 and 2, but not allow System Speed Dialling calls for the extensions with COSs 3, 4, and 5 according to TRS as follows:

COS No.

System Speed Dialling Class

Permitted

[Flowchart]

WARNING

The software contained in the TRS 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 on-premise PBXs or peripheral equipment to recognise the new codes as they are established will restrict the customer and users of the PBX from gaining access to the network and to these codes.
KEEP THE SOFTWARE UP TO DATE WITH THE LATEST DATA.

•

Emergency numbers, such as the police or fire services, should be stored (

Emergency Number [309]) so that they are not barred by TRS.

•

Host PBX Access Code/Carrier Exception Code
TRS checks can be carried out on telephone numbers dialled using a Host PBX Access code (

1.5.2.7 Host PBX Access Code (Access Code to the Telephone Company from a Host PBX)) or Carrier Exception code.

Access Code Type

Access Code is stored in the PBX

Access Code is not stored in the PBX

Access Code is dialled

Access Code is not dialled

Host PBX Access Code*¹

TRS ignores the code and checks the remaining digits.

Number dialled is not an outside (CO) line call, so TRS does not check the number.

TRS checks the entire number.

Carrier Exception Code*²

TRS ignores the code and checks the remaining digits.

TRS checks the entire number.

*¹

Host PBX Access Code [403]

*²

Carrier Exception Code [300]

•

The inter-digit timer (

Inter-digit Time [208]) applies until the TRS check is completed. When the timer expires, the outgoing outside (CO) line call is disconnected while dialling, if enabled through system programming (

No Dial Disconnection [211]). For a single line telephone (SLT), an outgoing outside (CO) line call will be released from the DTMF (Dual Tone Multi-Frequency) receiver when the inter-digit timer expires.

•

TRS—Extension Lock Class
The COS of extensions locked by the Extension Lock or Remote Extension Lock feature (

1.8.3 Extension Lock) can be assigned (

TRS—Extension Lock Class [312]) so that even a locked extension can make outside (CO) line calls. The higher COS number will take precedence. If, for example, COS 3 is assigned to an extension (

TRS-COS—Day/Night/Lunch [601-603]) and the COS of locked extensions is assigned as "4", when the extension is locked, the PBX allows the extension user to make outside (CO) line calls using COS 4.

•

The PBX can also be programmed to perform a TRS check for numbers that contain nondigits (

or #) (

TRS Check for * and # [125]). If TRS check is disabled, the PBX ignores any nondigits that are dialled when checking, which is useful in preventing some unauthorised calls.

An extension user can override TRS temporarily to make a toll call from a toll-restricted telephone (

1.8.1 Toll Restriction (TRS)). The extension user can carry out this feature by entering the appropriate account code before dialling the telephone number (

Account Code [310]).

[Flowchart]

Extension users can lock their telephones to prevent unauthorised use. This is useful for situations when extension users must leave their desks temporarily. Any 4-digit code can be used to lock and unlock an extension.
This feature is also known as Electronic Station Lockout.

•	Remote Extension Lock An extension assigned as the operator or manager extension can remotely lock or unlock an extension using a Direct Station Selection (DSS) Console. This feature functions only if the operator or manager has set the extension password. When the operator or manager locks an extension remotely, the extension's user cannot unlock it. When a user locks an extension, the operator or manager extension can override the lock and unlock the extension. This feature is also known as Remote Station Lock Control.
•	TRS—Extension Lock Class The class of service (COS) of extensions locked by the Extension Lock or Remote Extension Lock feature can be assigned ( TRS—Extension Lock Class [312]) so that even a locked extension can make outside (CO) line calls. The higher COS number will take precedence. If, for example, COS 3 is assigned to an extension ( TRS-COS—Day/Night/Lunch [601-603]) and the COS of locked extensions is assigned as "4", when the extension is locked, the PBX allows the extension user to make outside (CO) line calls using COS 4.
•	Extension Lock—CANCEL ALL The operator or manager can cancel this feature for all extensions simultaneously.
•	This feature also functions as Incoming Call Log Display Lock ( 1.16.2 Incoming Call Log). The Incoming Call Log for the common area can only be locked or unlocked by the operator and manager.

•	1.6.1.5 Speed Dialling—Personal/System
•	2.2.1 Class of Service (COS)

•	1.5.3 Preventing Other People from Using Your Telephone (Extension Lock)
•	2.1.1 Locking Other Extensions (Remote Extension Lock)
•	2.1.7 Changing System Settings Using Programming Mode

•	1.2.6 Using Your Calling Privileges at Another Extension (Walking COS)
•	2.1.7 Changing System Settings Using Programming Mode