Nortel NTBX27AA (OPTera Metro / PDH-SDH / Passport-MSS / networking portfolio) Telecom System Card / Module

The Nortel NTBX27AA is a DMS-100 ISDN Line Card, a peripheral circuit pack from the NTBX card family used in Nortel’s DMS-100 digital central-office switch to terminate Basic Rate ISDN subscriber lines. It provides the D-channel signalling and B-channel bearer interface between an ISDN subscriber loop and the switch’s digital fabric, sharing its NTBX numbering with the platform’s plain analogue and specialty line-card variants. DMS-100 offices of this generation remain in service at telephone operators worldwide, and genuine spares like this restore ISDN line capacity after a card failure or support planned ISDN growth. Specifiers should confirm exact frame, shelf and generic-program-load compatibility before ordering. Tech-Star is UK-based and ships worldwide. Contact our sales team for current availability and pricing.