Nortel NTK557PA (telecommunications transmission and networking portfolio) Telecom System Card / Module

The Nortel NTK557PA is an 80G/20G VT1.5/VC-12 cross-connect circuit pack for the OME 6500 platform, sharing its NTK557-prefixed part numbering with the 20G/20G VT1.5/VC-12 cross-connect card already confirmed in this catalogue; this variant steps up the cross-connect’s aggregate capacity to 80G while retaining the same VT1.5/VC-12 low-order granularity. The cross-connect card performs the shelf’s time-slot switching between tributary and aggregate cards at the low-order (VT1.5/VC-12) level. Tech-Star supplies this as a secondary-market spare for maintaining or expanding an existing OME 6500 shelf’s switching capacity. Cross-connect cards of this kind are typically upgraded rather than repaired when a shelf’s low-order switching capacity is exhausted, so the 80G variant is a common replacement for an original 20G card on a shelf whose tributary count has grown over time.