Isdn Hardware; Pri Hardware; Bri Hardware - Nortel BCM50 Configuration Manual

542 Appendix C ISDN overview
• allows incoming calls to be routed to sets based on service type and digits received
• provides the ability to map user-dialed digits to a service type on a Call-by-Call basis
• allows long distance carrier selection through user-dialed Carrier Access Codes
Consult your customer service representative to determine how your dialing plan is configured.

ISDN hardware

To support connections to an ISDN network and ISDN terminal equipment, your BCM must be
equipped with a BRI S/T Media Bay Module (BRIM) or a Digital Trunk Media Bay Module
(DTM) card configured for PRI.
Refer to the following for a description of the BRI and PRI hardware:
• "PRI hardware" on page 542
• "BRI hardware" on page 542

PRI hardware

The Digital Trunk Media Bay Module (DTM) is configured for PRI. In most PRI network
configurations, you need one DTM configured as PRI to act as the primary clock reference. The
only time when you may not have a DTM designated as the PRI primary clock reference is in a
network where your BCM system is connected back-to-back with another switch using a PRI link.
If the other switch is loop-timed to your BCM system, your DTM (PRI) can be designated as a
timing master.
If your BCM has more than one DTM configured as PRI, you must assign the first DTM as the
primary external, the second DTM as the secondary reference.

BRI hardware

The loops on the BRI module can be programmed to support either network or terminal
connections. This allows you to customize your arrangement of lines, voice terminals, data
terminals, and other ISDN equipment. The following describes some basic hardware
configurations for network and terminal connections for each loop type.
A BRI module provides four loops. Each loop can be individually programmed as:
• an S reference point connection (S loop) to ISDN terminal equipment (TE), or
• a T or S reference point connection (T loop or S loop) to an ISDN network using an
external NT1
NN40020-603 NN40020-603