The NORTEL 25USX00751CAA is a data interface card belonging to the UNIDA function family, originally developed by Keymile (MFR ID 120771) and used within the Keymile UMUX multi-service access platform. Nortel rebranded/resold Keymile UMUX equipment in certain markets, so this card carries the Nortel label while sharing the same UMUX architecture and part-numbering series as Keymile-branded units. UNIDA cards provide synchronous/asynchronous TDM data interfaces for business data services — the family includes variants for V.35 (UNIDA 432 V35, P/N 25USX00751BAE) and X.21/X.24 (UNIDA X24, P/N 25USX00751JAS) interfaces, with the specific electrical interface determined by the card's suffix code. The card features two red status/alarm LEDs on the front panel. UMUX is a carrier-grade multiplexer platform used by dedicated network operators such as utilities, railways, and airports. Keymile was acquired by ABB in 2017, and the UMUX range was later discontinued; this card is now sourced mainly as a refurbished or pulled spare part.
Key Features:
- One-slot plug-in data interface card for UMUX subracks
- Part of the UNIDA family of synchronous/asynchronous TDM data interface cards
- Two front-panel status/alarm LEDs
- Nortel-branded (OEM manufactured by Keymile)
- Managed via Keymile UCST/UNEM network management tools
Technical Specifications:
- Manufacturer Part Number: 25USX00751CAA
- PCS (Product Change State): REL 01
- Manufacturer ID: 120771
- Alternate/Board Reference: 3.3564.433
- Functional Unit Type: UNIDA
- Manufacturer: Nortel (OEM: KEYMILE AG)
- Platform Compatibility: UMUX
- Form Factor: Single mechanical slot, standard UMUX plug-in unit
- Indicators: 2 x red status/alarm LEDs
- Options: N0 Opt. (no options fitted)
- Date Code: 2001W20 (week 20, 2001)
- Note: Exact interface type (V.35, X.21/X.24, V.24/V.28, or RS-485) for this specific unit was not confirmed via the label — recommend verifying against Keymile/DZS legacy documentation if the precise interface standard is needed.
