Nortel BCM50, Installation And Maintenance Manual

Page: 41 / 246

Chapter 2 Introducing the BCM50 hardware 41
BCM50 Installation and Maintenance Guide
Digital trunk media bay module
The digital trunk media bay module (DTM) connects to standard digital PSTN T1/fT1, E1/fE1 or
PRI ISDN line using either a digital or PRI line. The DTM also supports DASS2, DPN22, Q.SIG,
and MCDN over ISDN:
• On North American BCM50 systems, the DTM connects a T1 or PRI circuit to the BCM50;
T1 circuits provide 24 digital channels to the PSTN and PRI circuits provide 23 digital
channels to the PSTN.
• On International BCM50 systems, the DTM connects to ETSI ISDN (E1) or PRI (EI) circuit to
a BCM50, providing a maximum of 30 digital channels to the PSTN.
The front bezel of the DTM has an RJ-48C connector that connects the DTM to the service
provider connection point. The faceplate also has a set of monitor jacks you can use to monitor the
span.
There are six additional LEDs on the front of the DTM. For information about these additional
LEDs, refer to
“DTM LEDs” on page 65 .
Figure 7 shows the DTM module interfaces.
Figure 7 DTM faceplate
Basic rate interface media bay module
The basic rate interface media bay module (BRIM) connects a maximum of four BRI ISDN loops
to the BCM50 system. The BRIM only recognizes the T-interface used in European networks. To
use the BRIM with the U-interface, typical in North American networks, you require an external
NT1 box to convert the U-interface to a T-interface.
Each BRI ISDN loop you connect adds two telephone lines to the BCM50 system. Therefore, each
BRIM adds a maximum of eight lines to the BCM50 system through the four RJ-48C jacks on the
faceplate. The LEDs beside each RJ-48C jack are on when the ISDN line is active.
Figure 8 on
page 42 shows the BRIM faceplate LEDs and connections.
Monitor jacks RJ-48C digital
telephone line
connector