QNAP CAB-DAC15M-SFP28 SFP28 25GbE Twinaxial Direct Attach Cable
Overview
The CAB-DAC15M-SFP28 is a 25GbE SFP28 twinaxial direct attach cable (DAC) with a 1.5-meter run length. It connects two SFP28-equipped devices — NAS units, switches, or servers — at 25 Gigabit speeds without the cost or latency overhead of optical transceivers and fiber patch cords. At 1.5M, it suits same-rack or adjacent-rack connections in dense server and network switch environments where short-haul copper is the practical choice. The passive copper design draws no separate power and generates less heat than active optical alternatives at this distance.
Compatibility
Designed for use with QNAP NAS and storage platforms equipped with SFP28 25GbE ports, including QNAP devices in the TVS-hx88, TVS-hx77, and similar high-end NAS families that carry 25GbE expansion cards or onboard SFP28 interfaces. Also compatible with any standards-compliant SFP28 port on third-party 25GbE switches and servers — the SFP28 MSA form factor ensures broad interoperability across vendors. For runs exceeding 1.5M or cross-room links, pair with an active optical cable or SFP28 transceiver and fiber instead. For 100GbE aggregation uplinks, the QNAP CAB-DAC15M-Q28 (QSFP28) is the appropriate step-up in the same cable family.
Installation Notes
Passive DAC cables require no firmware or driver configuration — insert into matching SFP28 cages on both ends and the link negotiates automatically. Verify that the host NAS or switch cage accepts passive DAC rather than active optical only; most QNAP SFP28 ports explicitly support passive DAC. Keep bend radius generous — twinaxial copper stiffens under tight routing and can degrade signal integrity if kinked near the connector boot. Label both ends at installation; passive DACs are directional by convention even when electrically symmetric, and consistent labeling prevents confusion during troubleshooting.
