Cisco QDD-400G-SR4.2-BD Compatible 400G QSFP-DD SR4.2 Transceiver Module
This Cisco QDD-400G-SR4.2-BD compatible transceiver provides 400G connectivity in a hot-swappable QSFP-DD package. Its optical design operates at 850nm,910nm for up to 70m on OM3 / 150m on OM5, using MTP/MPO-12 (UPC). Complete parameters and related OEM references help project teams keep OEM references, delivery records and port schedules aligned.
OEM Part Number: QDD-400G-SR4.2-BDHT Part Number: QDD-SR4.2-400G
Product Highlights
- Compatible alternative to Cisco QDD-400G-SR4.2-BD
- 400G connectivity at 425Gbps
- Optical wavelength: 850nm,910nm
- Specified reach: 70m on OM3 / 150m on OM5
- MTP/MPO-12 (UPC) / MMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| Cisco Compatible | QDD-400G-SR4.2-BD |
|---|---|
| Manufacturer | HT |
| HT Part Number | QDD-SR4.2-400G |
| Form Factor | QSFP-DD |
| Max. Data Rate | 425Gbps |
| Wavelength | 850nm,910nm |
| Max. Cable Distance | 70m@OM3/150m@OM5 |
| Connector | MTP/MPO-12 (UPC) |
| Media | MMF |
| Transmitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -6.5dBm~4dBm |
| Minimum Receiver Power | -8.5dBm |
| Power Budget | 2dB |
| Receiver Overload | 4dBm |
| Max. Power Consumption | 12W |
| Extinction Ratio | 3dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation (Electrical) | 8x50G-PAM4 |
| Modulation (Optical) | 8x50G-PAM4 |
| DSP | TX and RX |
| Inbuilt FEC | NO |
| Core Size | 50/125µm |
| Packaging Technology | COB |
| Protocols | QSFP-DD MSA, IEEE 802.3-2015 |
Project Documentation and Traceability
Large deployments are easier to audit when the order code, optical standard and endpoint record agree. Keep the OEM reference in the compatibility document and the HT part number on the packing list. Labels and carton groups can be arranged by rack or port plan so installers need not identify modules by appearance. For this model, the principal parameters are data rate 425Gbps, wavelength 850nm,910nm, rated reach 70m on OM3 / 150m on OM5.
Cisco Compatibility and Factory Testing
Compatibility testing for QDD-400G-SR4.2-BD combines identification with a live link and available transmit, receive and alarm information. Connector condition is inspected separately. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
Applications and Optical Link Design
Typical deployments include switch-to-switch, switch-to-server and aggregation links inside a data hall or between adjacent equipment rooms. The MTP/MPO-12 (UPC) interface connects to the specified multimode cabling, and the stated reach depends on fiber grade and link loss. Keep this interface on the matching multimode optical standard rather than connecting it directly to a single-mode wavelength or reach variant.
Before deployment, check the host port type, supported data rate and firmware requirements. The 400G interface configuration must match the remote equipment; sharing a QSFP-DD housing alone does not make two transceiver types interoperable.
The multimode channel should use the fiber grade associated with the stated 70m on OM3 / 150m on OM5 reach. Keep the MTP/MPO-12 (UPC) end faces clean and avoid tight bends. Different multimode standards are not interchangeable merely because they share a connector.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -6.5dBm~4dBm; the stated optical power budget is 2dB. Digital diagnostics make later maintenance easier when baseline values are captured at installation. Save the initial readings with the port and OEM reference, then investigate meaningful changes rather than reacting to a single transient value. Diagnostic support depends on the host as well as the module, so unavailable fields should be confirmed with the platform documentation. Diagnostic monitoring is listed as Supported. Before every insertion, keep dust caps in place until the patch lead is ready, avoid touching the optical end face and use an appropriate inspection and cleaning procedure. Do not look into an active optical interface.
Frequently Asked Questions
Is this an original Cisco transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-400G-SR4.2-BD, not an original Cisco-branded module.
Which fiber and connector are required?
Use MTP/MPO-12 (UPC) with MMF. The specified maximum reach is 70m on OM3 / 150m on OM5, subject to fiber quality and total link loss.
Can it be mixed with another wavelength or reach version?
Only when the two ends share the same optical standard, wavelength plan and supported data rate. Check the exact part numbers and link budget rather than relying only on the module form factor.
Ordering Information
Use QDD-400G-SR4.2-BD as the compatibility cross-reference and QDD-SR4.2-400G as the HT ordering identity. Keep other reaches or wavelength directions on separate order lines. Neutral labels, customer packaging and project-specific compatibility review are available on request.
Shipping and Lead Time
Standard configurations normally ship within one to three working days, with production lead times confirmed for larger quantities. International courier, air freight and sea freight are available; customer courier accounts and nominated forwarders are accepted.
Quality Assurance and Packaging
Quality control covers the optical or electrical interface, host identification and operating link. The verified unit is then individually protected and cartoned. Customer references, rack groups and project packing lists can be added for volume orders.
