Juniper Networks QDD-400G-VSR4 Compatible 400G QSFP-DD SR4 Transceiver Module
The QDD-400G-VSR4 compatible module serves equipment requiring a 400G QSFP-DD interface with 850nm optics and a 30m on OM3 / 50m on OM4 rating. Connection is through MPO-12/APC. Product data, application guidance and factory verification are presented together to support project teams keep OEM references, delivery records and port schedules aligned.
OEM Part Number: QDD-400G-VSR4HT Part Number: QDD-400G-VSR4
Product Highlights
- Compatible alternative to Juniper Networks QDD-400G-VSR4
- 400G connectivity at 400Gbps
- Optical wavelength: 850nm
- Specified reach: 30m on OM3 / 50m on OM4
- MPO-12/APC / MMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| Juniper Networks Compatible | QDD-400G-VSR4 |
|---|---|
| Manufacturer | HT |
| HT Part Number | QDD-400G-VSR4 |
| Form Factor | QSFP-DD |
| Max. Data Rate | 400Gbps |
| Wavelength | 850nm |
| Max. Cable Distance | 30m@OM3/50m@OM4 |
| Connector | MPO-12/APC |
| Media | MMF |
| Transmitter Type | VCSEL 850nm |
| Receiver Type | PIN |
| TX Power | -4.6~4dBm |
| Minimum Receiver Power | -6.4dBm |
| Power Budget | 1.8dB |
| Receiver Overload | 4dBm |
| Max. Power Consumption | 8W |
| Extinction Ratio | 2.5dB |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation (Electrical) | 8x50Gbps-PAM4 |
| Modulation (Optical) | 4x100Gbps-PAM4 |
| DSP | TX and RX |
| Inbuilt FEC | Support |
| Core Size | 50/125µm |
| Packaging Technology | COB |
| MTBF | 1410258 Hours (@40°C, 90% CL) |
| Application | 400G Ethernet |
| Protocols | QSFP-DD MSA, CMIS Rev5.0, IEEE 802.3df-2024 |
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 400Gbps, wavelength 850nm, rated reach 30m on OM3 / 50m on OM4.
Juniper Networks Compatibility and Factory Testing
Factory verification starts with the expected QDD-400G-VSR4 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.
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-12/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.
For this multimode module, confirm fiber grade, modal bandwidth and total loss before commissioning. The 30m on OM3 / 50m on OM4 figure applies only under suitable cabling conditions. Inspect every MPO-12/APC mating point and match the remote optical standard.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -4.6~4dBm; the stated optical power budget is 1.8dB. During commissioning, record the host diagnostic readings after the link has stabilized and compare them with those limits. DOM values are useful operational indicators, but they do not replace calibrated optical measurements when a link is marginal. Investigate unexpected loss through connector inspection, cleaning and a channel measurement before replacing the module. 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 Juniper Networks transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies QDD-400G-VSR4, not an original Juniper Networks-branded module.
Which fiber and connector are required?
Use MPO-12/APC with MMF. The specified maximum reach is 30m on OM3 / 50m 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.
Ordering Information
When ordering, specify QDD-400G-VSR4, QDD-400G-VSR4, 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.
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-VSR4 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.
