Add T1 to your Norstar system. Save money on your phone bill. Compatible only with the core Modular ICS unit, the Digital Trunk Interface cartridge provides for up to 24 digital T1 or ISDN-PRI channels on your system. It comes fully equipped with a built in CSU (Channel Service Unit) to support the integrity of digital signaling.
This cartridge requires either the Services Cartridge or the Combination Fiber 6-Port Services Cartridge. The core Modular ICS unit can support up to two Digital Trunk Cartridges for a total of up to 48 T1 or ISDN-PRI (digital) lines. This unit cannot be used in Trunk Modules