Nortel NT4N66AB (telecommunications transmission and networking portfolio) Telecom System Card / Module

The Nortel NT4N66AB is a CompactPCI (cPCI) Core Network Interface Transition Card for Nortel’s Succession Communication Server for Enterprise (CSE) 1000 platform, part of the NT4N-prefixed cPCI transition-card family that also includes the system utility, multimedia disk and Core-to-Network Interface (CNI-2) transition cards catalogued alongside it. A transition card sits at the rear of a cPCI shelf, carrying the physical cabling connections through to the active card fitted at the front, so replacing it restores rear-panel connectivity for the shelf’s core network-interface card without needing to touch the active card itself. Tech-Star supplies this as a secondary-market spare for maintaining an existing CSE 1000 cPCI cabinet. A transition card carries no active electronics of its own, so a fault that looks like a failed core network-interface card can sometimes be resolved simply by replacing this rear card rather than the more expensive active card fitted at the front of the shelf.