Arista Networks QDD-400G-SR8 Compatible 400G QSFP-DD SR8 Transceiver Module

This Arista Networks QDD-400G-SR8 compatible transceiver provides 400G connectivity in a hot-swappable QSFP-DD package. Its optical design operates at 850nm for up to 70m on OM3 / 100m on OM4, using MPO-16/APC. Complete parameters and related OEM references help structured fiber installations preserve a documented and serviceable optical channel.
OEM Part Number: QDD-400G-SR8HT Part Number: QDD-SR8-400G
Product Highlights
- Compatible alternative to Arista Networks QDD-400G-SR8
- 400G connectivity at 400Gbps
- Optical wavelength: 850nm
- Specified reach: 70m on OM3 / 100m on OM4
- MPO-16/APC / MMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| Arista Networks Compatible | QDD-400G-SR8 |
|---|---|
| Manufacturer | HT |
| HT Part Number | QDD-SR8-400G |
| Form Factor | QSFP-DD |
| Max. Data Rate | 400Gbps |
| Wavelength | 850nm |
| Max. Cable Distance | 70m@OM3/100m@OM4 |
| Connector | MPO-16/APC |
| Media | MMF |
| Transmitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -6.5~4dBm |
| Minimum Receiver Power | -8.4~4dBm |
| Power Budget | 1.9dB |
| Receiver Overload | 4dBm |
| Max. Power Consumption | 10W |
| 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 (Chip on Board) Packaging |
| MTBF | 1671961 Hours (@40°C, 90% CL) |
| Application | 400G Ethernet |
| Protocols | QSFP-DD MSA, CMIS 4.0, IEEE 802.3cd |
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 MPO-16/APC 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 / 100m on OM4 reach. Keep the MPO-16/APC end faces clean and avoid tight bends. Different multimode standards are not interchangeable merely because they share a connector.
Arista Networks Compatibility and Factory Testing
The module is checked for host recognition as QDD-400G-SR8, link establishment and diagnostic reporting. Physical cage fit alone is not treated as evidence of compatibility. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -6.5~4dBm; the stated optical power budget is 1.9dB. 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. 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.
Structured Fiber Pathways and Serviceability
Treat the transceiver as part of the complete channel. Follow the intended patch-panel route, maintain bend control and leave service access around the port. Confirm connector polish and fiber type at every mated pair; a documented service allowance is preferable to excess slack concealed inside a rack. For this model, the principal parameters are data rate 400Gbps, wavelength 850nm, rated reach 70m on OM3 / 100m on OM4.
Ordering Information
Use QDD-400G-SR8 as the compatibility cross-reference and QDD-SR8-400G 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
Each QDD-400G-SR8 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 Arista Networks transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-400G-SR8, not an original Arista Networks-branded module.
Which fiber and connector are required?
Use MPO-16/APC with MMF. The specified maximum reach is 70m on OM3 / 100m on OM4, 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.
10/100BASE-T SFP