NTAB1829 refers to theNortel NTAB1829 Fiber Cable Assembly (NTAB1829) - MetrolineDirect, a fiber optic cable used in olderNorstar MICS telephone systems(Modular ICS) to connect expansion modules like trunk or station cards to the main control unit, often coming on a reel and connecting various fiber/analog modules. It's a specific network accessory for Avaya/Nortel communication systems, sometimes called the DS-30 Fiber Cable.