Cisco QDD-2X400G-FR4 Compatible 800G QSFP-DD Transceiver Module
Built for hosts recognizing QDD-2X400G-FR4, this HT-manufactured QSFP-DD module delivers 800G transmission at 1271nm, 1291nm, 1311nm and 1331nm. Its rated reach is 2km, with Dual 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-2X400G-FR4HT Part Number: QDD-2FR4-800G
Product Highlights
- Compatible alternative to Cisco QDD-2X400G-FR4
- 800G connectivity at 850Gbps (8x 106.25Gbps)
- Optical wavelength: 1271nm, 1291nm, 1311nm and 1331nm
- Specified reach: 2km
- Dual Duplex LC/UPC / SMF interface
- Factory compatibility verification and optical performance testing before shipment
Specifications
| Cisco Compatible | QDD-2X400G-FR4 |
|---|---|
| Manufacturer | HT |
| HT Part Number | QDD-2FR4-800G |
| Form Factor | QSFP-DD |
| Max Data Rate | 850Gbps (8x 106.25Gbps) |
| Wavelength | 1271nm, 1291nm, 1311nm and 1331nm |
| Max Cable Distance | 2km |
| Connector | Dual Duplex LC/UPC |
| Media | SMF |
| Transmitter Type | EML |
| Receiver Type | PIN |
| TX Power | -3.2~4.4dBm |
| Minimum Receiver Power | -7.2dBm |
| Power Budget | 4dB |
| Receiver Overload | 4.4dBm |
| Max Power Consumption | 17W |
| Extinction Ratio | ≥3.5dB |
| Modulation (Electrical) | 8x100G-PAM4 |
| Modulation (Optical) | 8x100G-PAM4 |
| Packaging Technology | COB (Chip on Board) Packaging |
| CDR (Clock and Data Recovery) | TX and RX Built-in DSP |
| Inbuilt FEC | No |
| Protocols | IEEE 802.3cu-2021, IEEE 802.3ck-2022, QSFP-DD MSA HW Rev 6.01, CMIS Rev 5.0 |
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 800G 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 2km route. Keep the Dual 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 -3.2~4.4dBm; the stated optical power budget is 4dB. A sound acceptance record includes link state, diagnostic temperature, supply voltage and transmit or receive levels where the host exposes them. Compare the readings with the stated ranges rather than treating any received light as proof of adequate margin. Persistent alarms or borderline values should trigger an end-face and complete-channel inspection. 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 850Gbps (8x 106.25Gbps), wavelength 1271nm, 1291nm, 1311nm and 1331nm, rated reach 2km.
Cisco Compatibility and Factory Testing
Compatibility testing for QDD-2X400G-FR4 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.
Ordering Information
When ordering, specify QDD-2X400G-FR4, QDD-2FR4-800G, quantity and intended host platform. Project labels can repeat these details for receiving and asset records. Neutral labels, customer packaging and project-specific compatibility review are available on request.
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.
Frequently Asked Questions
Is this an original Cisco transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-2X400G-FR4, not an original Cisco-branded module.
Which fiber and connector are required?
Use Dual Duplex LC/UPC with SMF. The specified maximum reach is 2km, 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.