The NTBB20 12X0 Fiber Trunk Module is installed in conjunction with a 2-Port or 6-Port expansion card, and is used to add trunk interfaces to the core Modular ICS. 12x0 Fiber Trunk Modules are connected to the Modular ICS by a fiber DS-30 cable. Each Fiber Trunk Module holds up to three Trunk Cards. Any analog trunk card is supported, with the number of additional lines depending on the card installed. Digital Trunk Interface cards are now supported in Slot 1 of the first 12x0 Fiber Trunk Module, in MICS 5.0 or higher. ISDN-BRI cards are supported on Trunk Modules 3 and 4 (2-port expansion) or Trunk Modules 7 and 8 (6- or 12-port expansion). Services Cards and Combination Services Cards are not supported. There is one emergency transfer port per Trunk Module.

Adds three slots for analog trunk cards All analog trunk cards are supported Services cards are not supported ISDB BRI cards supported in specific slots Digital Trunk Interface cards supported in specific slots One emergency transfer port for power outages Compatible with all releases of Norstar Modular ICS