Nortel NTHR13BA (telecommunications transmission and networking portfolio) Telecom System Card / Module

The Nortel NTHR13BA is a Balanced E1 Alarm/Bits Module for the Nortel Passport 15000 / Multiservice Switch (MSS) 15000 platform, the balanced-E1 counterpart to the DS1 timing module used in the same shelf family. It distributes the shelf’s building-integrated timing (BITS) reference over a balanced E1 interface and relays external alarm-contact status to the switch’s management plane, keeping the platform’s internal clock synchronised across E1-based deployments. Passport 15000 / MSS 15000 shelves remain active in a number of legacy carrier networks, and this timing/alarm module is a routine spares item when maintaining or refurbishing an existing shelf. Confirm the exact shelf generation before ordering, since timing modules are not interchangeable across Passport hardware revisions. Tech-Star (UK-based, shipped worldwide) supplies Nortel Passport/MSS spares to support ongoing network maintenance.