Nortel Networks BCM50 manual Digital trunk media bay module

Chapter 2 Introducing the BCM50 hardware 41

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

Monitor jacks RJ-48C digital telephone line connector

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.

BCM50 Installation and Maintenance Guide