The Trunk Barring feature provides the option of denying or allowing a direct or modified connection between customer-defined routes.
Trunk Barring works in conjunction with Route Access Restriction Tables (ARTs) defined in LD 16. Trunk Barring is applied on a route basis. Table 18 shows the four route categories that Trunk Barring recognizes, and the types of routes in each category.
Operating parameters
When activated in conjunction with the Route Access Restriction Tables, Trunk Barring can prohibit previously allowed connections. Previously restricted connections cannot be lifted or circumvented by Trunk Barring. Trunk Barring applies to all methods of connecting the trunks (for example, dialing route access, call modification, attendant extension). However, it does not apply to RAN, Music, AWU, or CAS trunks as it is inconsistent with their defined purpose.
Table 18
Trunk Barring route categories
Route category Route types
Central Office Trunk (COT) COT, FEX, WAT Direct Inward Dialing DID, DOD
TIE ATVN, TIE, CAA, CAM, CSA
Feature interactions
The Trunk Barring feature has the following feature interactions. Access Restrictions
Trunk Barring is at the top of the hierarchy for access restrictions. Attendant-extended calls
When an attendant attempts to extend an Originating Trunk Connection on a barred route, overflow tone is given.
Call Transfer
The originator of a call transfer, unless otherwise restricted, is able to connect to a denied party on a consultation basis. Operating the Transfer key on a Business Communication Set (BCS) telephone or going on hook on an analog (500/2500-type) telephone does not result in a call transfer if the Originating Trunk Connection is barred. The user of a BCS telephone remains connected to the denied party until releasing the connection and returning to the held Originating Trunk Connection. The user of an analog (500/2500-type) telephone is rerung by the Originating Trunk connection when a transfer is attempted and denied.
Call Forwarding
If an Originating Trunk Connection is forwarded to a barred route, it receives the intercept treatment specified in the customer data block. Conference Calls
The originator of a conference call can connect to a barred route only on a consultation basis. A switchhook flash from an analog (500/2500-type) telephone results in a reestablished connection with the Originating Trunk Connection. The use of a BCS telephone must release the barred connection to return to the Originating Trunk connection or the conference containing the Originating Trunk connection; operating the Conference key on a BCS telephone has no effect. An attendant can return to the Originating Trunk Connection or the conference containing the Originating Trunk Connection by releasing the barred connection. This is done by pressing the RLS DEST key; pressing the Conference key has no effect.
Intercept Treatment/Direct Trunk Access
When an Originating Trunk Connection (OTC) attempts a trunk connection to a route that is restricted by its Access Restricted Table, the connection is not allowed. The intercept treatment specified in the customer data block is applied.
Enhanced Night Service
Any incoming trunk call that is routed by Enhanced Night Service to a telephone from which it is barred is not connected. Overflow tone (fast busy) is given to the incoming trunk instead.
Any incoming trunk call that is routed to an outgoing Public Network trunk is barred if Enhanced Night Service is active. Overflow tone (fast busy) is given to the incoming trunk instead. This restriction is in addition to the configured trunk barring for the system.
Toll Operator Break In
Trunk Barring results in intercept treatment for all route types that can be barred except Toll Operator Break In.
Feature packaging
This feature requires Trunk Barring (TBAR) package 132. Feature implementation
In most cases that require barring, only one Access Restriction Table (ART) is necessary. When a new route is created (in LD 16), the default ART defined for that route type is assigned to the route. Use LD 56 to change the ART associated with a route or to handle other nondefault conditions. LD 56 – Enter or change Trunk Barring parameters. (Part 1 of 2)
Prompt Response Description
REQ NEW CHG Add or change Trunk Barring parameters. TYPE TBAR Add or change Access Restriction Tables (s)
(ARTs).
-ART 1-63 Select ART to add or change.
-DENY yyy yyy
ALL Xyyy Xyyy
ART numbers denied originating trunk connection (OTC).
Deny all ARTs to OTC. ART numbers allowed to OTC.
TYPE RART Change ART number for the route.
-CUST xx Customer number as defined in LD 15.
-ROUT
0-511
0-127
Route number
Range for Large System and CS 1000E system.
Range for Small System, CS 1000S system, Media Gateway 1000B, and Media
Gateway 1000T.
-ART 0-63 ART to assign to route.
Feature operation
No specific operating procedures are required to use this feature.
-COT (0)-63 COT,FEX, and WAT routes are assigned the
entered number.
-DID (0)-63 DID and DOD routes are assigned the
entered number.
-TIE (0)-63 ATVN, CAA, CAM, CSA, and TIE routes are
assigned the entered number.
OTH (0)-63 ADM, AID, DIC, MDM, PAG, and RCD routes
are assigned the entered number. LD 56 – Enter or change Trunk Barring parameters. (Part 2 of 2)