Section 700 - Operation
CO Trunk Interface - DID
The DID feature allows an extension to have a dedicated direct number. The dedicated number allows
calls to be made directly to the extension, without the caller going through the attendant.
The DID number may have from 1 to 4 digits (typically 4).
Each DID Trunk Interface card (VB-44520) supports up to 8 DID trunks.
Hardware Requirements
•
The -48V power supply is required.
Related Programming
•
N/A
Considerations
•
The DID Trunk card supports 1 to 4-digit dial-pulse (10 pps) or Dual Tone Multifrequency
(DTMF) signaling.
•
DID numbers must be between 0 and 9999.
CO Trunk Interface - Ground Start
Ground start trunks are supported in the System with the VB-44511 Loop Start/Ground Start trunk
interface. Each card supplies 8 circuits that can be individually configured for either loop start or
ground start operation.
Ground start trunks are useful in preventing call collision.
Hardware Requirements
•
When ground start trunks are used, the -48V power supply is required.
Related Programming
•
N/A
Considerations
•
N/A
CO Trunk Interface - ISDN BRI
The System supports ISDN BRI with the VB-44530 ISDN BRI interface unit. The VB-44530 is a T-
Point ISDN-BRI that supports 2 B (bearer) channels and 1 D (data) channel (2B + D; 192kbps). This
unit connects to an ISDN Data Service Unit (DSU). Point-to-point and point-to-multi operations are
selectable.
The ISDN-BRI supports enblock setting and enblock setting at the sub-address.
Hardware Requirements
•
N/A
Related Programming
•
N/A
576-50-700
DBS 576 (USA) issued September 2001
Chapter 3. System Features
3-21