QSAQ28-S28-BCC | Dell Compatible 100G to 25G SFP Adapter

Q: Will this work in place of the Dell QSAQ28-S28 or 407-BBZL?
A: Yes. The QSAQ28-S28-BCC is designed as a direct replacement for both Dell QSAQ28-S28 and 407-BBZL adapter modules. It conforms to QSFP28 MSA SFF-8665 and SFP28 MSA SFF-8402 standards, providing the same QSFP28 form factor and SFP28 receptacle. The adapter is plug-and-play compatible with Dell PowerSwitch platforms and supports data rates from 10.3125 Gbps to 25.78125 Gbps for both 10GB and 25GB Ethernet applications.

Q: Which Dell switches support this adapter?
A: This adapter is compatible with Dell PowerSwitch platforms that have QSFP28 ports and support single-lane SFP28 or SFP+ operation. Compatible switch families include PowerSwitch S-Series, Z-Series, and MX-Series models with QSFP28 interfaces. The host switch must recognize the adapter and downshift the port to 25GB or 10GB operation. Consult Dell documentation for your specific switch model to confirm adapter support.

Q: Can I use any SFP28 or SFP+ transceiver in this adapter?
A: The adapter accepts any standards-compliant SFP28 (25GB) or SFP+ (10GB) transceiver, Direct Attach Copper cable, or Active Optical Cable that matches Dell coding requirements for your switch platform. The adapter routes lane 1 of the QSFP28 host interface to the inserted SFP28 module, supporting data rates from 10.3125 Gbps to 25.78125 Gbps. DDM/DOM parameters from the inserted module are passed through to the switch for monitoring.

Q: Does this adapter require breakout mode configuration on the switch?
A: No. Unlike QSFP28 breakout cables that split four lanes into separate ports, this adapter uses only lane 1 and does not require breakout mode. The switch treats the adapter as a single-lane device and downshifts the port speed to match the inserted SFP28 or SFP+ module. Other QSFP28 ports on the same ASIC remain available for full 100GB operation. No port configuration or interface subdivision is necessary.

Q: What happens to the other three QSFP28 lanes when using this adapter?
A: The adapter connects only lane 1 of the QSFP28 electrical interface to the SFP28 receptacle. Lanes 2, 3, and 4 remain electrically inactive and are not routed to any connector. This single-lane design means the adapter occupies one physical QSFP28 port but does not consume multiple switch ports or require lane splitting. The switch ASIC recognizes the adapter and disables the unused lanes automatically, leaving adjacent QSFP28 ports fully functional for independent 100GB or other speed operation.