Nortel Networks 400 4.0 Manual De Usuario

Chapter 2 Introducing the BCM hardware

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The digital trunk media bay module (DTM) connects to a 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 BCM systems, the DTM connects a T1 or PRI circuit to the BCM system; 
T1 circuits provide 24 digital channels to the PSTN, while PRI circuits provide 23 digital 
channels to the PSTN.

•

On International BCM systems, the DTM connects an ETSI ISDN (E1) or PRI (EI) circuit to 
the BCM system, 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 

 shows the DTM module interfaces.

Figure 27   DTM faceplate

ISDN BRI

(see 

Connects a maximum of four ISDN BRI 
S/T interfaces.

GATM4/GATM8

(see 

Connects either four (GATM4) or eight 
(GATM8) analog public switched 
telephone lines to the BCM system.

Note: Refer to 

 for supported market profiles.

Warning: Install DTMs in the BCM main unit only. DTMs do not function if 
installed in the BCM expansion unit. 
If there are no empty MBM bays in the BCM main unit, move MBMs to the 
expansion unit to provide space for the DTMs.

Table 8   Trunk MBMs (Sheet 2 of 2)

Monitor jacks

RJ-48C digital 
telephone line 
connector