Check the listing for details. Nortel Avaya BCM Digital Trunk Module NT5B04AAAD NEW SEALED. Condition: New. Listed at 266.99 USD. Nortel Avaya BCM Digital Trunk Module NT5B04AAAD NEW SEALED Actual item shown in photosPlease make sure this is the correct product for you before purchaseAny questions? Don't hesitate contacting usFast shipping following payment The Nortel BCM Digital Trunk Media Bay Module connects to a standard digital PSTN T1/fT1, E1/fE1, or PRI ISDN line using either a digital or PRI lineAlso supports DASS2, DPN22, Q.SIG, and MCDN over ISDNOn 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 PSTNOn 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 PSTNThe front bezel of the DTM has an RJ-48C connector that connects the DTM to the service provider connection pointThe faceplate also has a set of monitor jacks you can use to monitor the span Compatibility: The Nortel BCM DTM is compatible with the BCM 200/400 Main Unit, BCM 400 Expansion Unit, and BCM 50 Expansion Unit I21