The Nortel Meridian NTRB21AA RLSE 12 Digital Input Phone Trunk Interface Card is a plug-in interface module for Nortel Meridian systems that provides 12 digital input channels for phone trunk signaling. Identified by part number NTRB21AA, this RLSE 12 card is designed for installation in compatible Meridian PBX hardware to support digital input functionality on trunk interfaces. Use cases include monitoring and processing digital input signals from phone trunks within a Meridian communications system.
