Cisco QDD-400G-LR4-S Compatible 400G QSFP-DD LR4 Transceiver Module
Built for hosts recognizing QDD-400G-LR4-S, this HT-manufactured QSFP-DD module delivers 400G transmission at 1271nm, 1291nm, 1311nm, and 1331nm. Its rated reach is 10km, with Duplex LC/UPC as the physical interface. The specifications and engineering guidance below support procurement teams match an equipment parts list to a clearly defined optical product, while keeping HT manufacture separate from the OEM cross-reference.
OEM Part Number: QDD-400G-LR4-SHT Part Number: QDD-LR4-400G
Product Highlights
- Compatible alternative to Cisco QDD-400G-LR4-S
- 400G connectivity at 425Gbps (4x 106.25Gbps)
- Optical wavelength: 1271nm, 1291nm, 1311nm, and 1331nm
- Specified reach: 10km
- Duplex LC/UPC / SMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| Cisco Compatible | QDD-400G-LR4-S |
|---|---|
| Manufacturer | HT |
| HT Part Number | QDD-LR4-400G |
| Form Factor | QSFP-DD |
| Max. Data Rate | 425Gbps (4x 106.25Gbps) |
| Wavelength | 1271nm, 1291nm, 1311nm, and 1331nm |
| Max. Cable Distance | 10km |
| Connector | Duplex LC/UPC |
| Media | SMF |
| Transmitter Type | CWDM EML |
| Receiver Type | PIN |
| TX Power | -2.7~5.1dBm |
| Minimum Receiver Power | -9.0dBm |
| Power Budget | 6.3dB |
| Receiver Overload | 5.1dBm |
| Max. Power Consumption | 9W |
| Extinction Ratio | 3.5dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation (Electrical) | 8x50G-PAM4 |
| Modulation (Optical) | 4x100G-PAM4 |
| CDR (Clock and Data Recovery) | TX & RX Built-in DSP |
| Inbuilt FEC | No |
| Core Size | G.652/9um |
| Packaging Technology | COB (Chip on Board) Packaging |
| Protocols | QSFP-DD MSA HW Rev 5.1, QSFP-DD, CMIS Rev 5.0, IEEE 802.3cu, 100G Lambda MSA |
Applications and Optical Link Design
Use this module for equipment interconnection over the specified single-mode fiber plant, including enterprise backbone, campus, metro or data-center interconnect links according to its rated distance. Confirm that both ends use the same optical standard and wavelength plan, and allow for connector, splice and patch-panel loss within the stated power budget.
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 single-mode link budget should include fiber attenuation, connectors, splices and panels over the intended 10km route. Keep the Duplex LC/UPC interface clean and match the remote optical standard. Consider receiver overload as well as insufficient power on short links.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -2.7~5.1dBm; the stated optical power budget is 6.3dB. 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.
Procurement and Asset Identification
A useful purchase order identifies the host platform, expected OEM code and optical standard separately. This prevents a module with the same housing but another wavelength, reach or identification profile from being substituted. For mixed deployments, keep one order line per OEM reference and reconcile each received unit with its intended port. For this model, the principal parameters are data rate 425Gbps (4x 106.25Gbps), wavelength 1271nm, 1291nm, 1311nm, and 1331nm, rated reach 10km.
Cisco Compatibility and Factory Testing
Factory verification starts with the expected QDD-400G-LR4-S identity and finishes with an operating host link. EEPROM data, diagnostic visibility and the stated optical parameters are assessed together. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
Ordering Information
Use QDD-400G-LR4-S as the compatibility cross-reference and QDD-LR4-400G 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.
Quality Assurance and Packaging
Each QDD-400G-LR4-S compatible module is inspected, powered up and functionally checked before protective packing. Dust caps and individual trays shield the interface during transport. Customer references, rack groups and project packing lists can be added for volume orders.
Frequently Asked Questions
Is this an original Cisco transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-400G-LR4-S, not an original Cisco-branded module.
Which fiber and connector are required?
Use Duplex LC/UPC with SMF. The specified maximum reach is 10km, 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.
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.