Appendix A. ARS and TRS Operation
This section provides a description of the TRS and ARS options on the DBS 576 PBX.
TRS Class Features
Each trunk and extension in the DBS 576 PBX is assigned to one of 50 TRS classes. Each
TRS class is assigned a Day TRS level and a Night TRS level for each Trunk group. This
assigned origination party TRS level is compared to the restriction TRS Level determined by
the dialed number. If the Origination Party TRS level is not higher than the restriction party
TRS level, the call is denied.
In addition, each TRS class is assigned settings such as Outgoing Dial Digit Restriction,
Incoming Dialing Restriction, Outgoing SSD Dialing Restriction, and * and # Dialing
Outgoing Dialed Digit Maximum
This TRS Class-based parameter sets the maximum number of digits that can be dialed for
outgoing calls in a TRS Class. The maximum number of digits can be set from 0-20. When
set to 0 (default), there is no restriction.
Dialing Restriction During Inbound Calls
Determines whether dialing during an incoming call is restricted on trunks in a TRS Class.
TRS Override on SSD Dialing
Determines whether SSD dialing will override TRS on extensions for a TRS Class.
Star (*) and Pound (#) Dialing Restriction
Determines if the * or # key can be used in dialing for a TRS Class.
TRS Level for Non-ARS Routing
For each of the 50 TRS classes, an originator's TRS level of 0-9 may be assigned for each
possible trunk group. When a call is originated on a particular trunk group, this value is used
to determine the originator's TRS level. From the dialed digits, a restriction TRS level (0-8)
is determined. If the originator's TRS level does not exceed the restriction TRS level, the call
is restricted. The higher the originator's TRS level, the less the restriction. If the originator's
TRS level is 0, no outside calls are allowed. If the originator's TRS level is 9, all outside calls
are allowed since this always exceeds the restriction TRS value which has a maximum value
When a trunk is accessed, the dialed digits can be analyzed to determine if the call will be toll
DBS 576 (USA), issued January 1999
Section 700 - Operation