HPE Aruba S4B38A Compatible 400G QSFP-DD Transceiver Module
The S4B38A compatible module serves equipment requiring a 400G QSFP-DD interface with 1528.77~1566.52nm optics and a Amplified: ≤120km Unamplified：≤40km rating. Connection is through Duplex LC/UPC. Product data, application guidance and factory verification are presented together to support procurement teams match an equipment parts list to a clearly defined optical product.
OEM Part Number: S4B38AHT Part Number: QDD-ZR-400G
Product Highlights
- Compatible alternative to HPE Aruba S4B38A
- 400G connectivity at 400Gbps
- Optical wavelength: 1528.77~1566.52nm
- Specified reach: Amplified: ≤120km Unamplified：≤40km
- Duplex LC/UPC / SMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0℃ to 70°C(32 to 158°F)
Specifications
| Aruba Compatible | S4B38A |
|---|---|
| Manufacturer | HT |
| HT Part Number | QDD-ZR-400G |
| Form Factor | QSFP-DD |
| Max. Data Rate | 400Gbps |
| Wavelength | 1528.77~1566.52nm |
| Max. Cable Distance | Amplified: ≤120km Unamplified：≤40km |
| Connector | Duplex LC/UPC |
| Media | SMF |
| TX Power | -13~-9dBm |
| RX Power | Amplified: Full Rx OSNR tolerance: -12~0dBm Extended range: -15~1dBm Unamplified: -20~0dBm |
| Max. Power Consumption | 18.5W |
| Minimum Receiver Power | Amplified: -12dBm Unamplified: -20dBm |
| DDM/DOM | Supported |
| Commercial Temperature Range | 0℃ to 70°C(32 to 158°F) |
| Inbuilt FEC | CFEC |
| Modulation Format | DP-16QAM |
| CD Robustness | 2400(ps/nm) |
| OSNR Tolerance | 26dB/0.1nm |
| Protocols | OIF 400ZR, OIF-CMIS-05.2, OIF-C-CMIS-01.2, QSFP-DD-Hardware-Rev6.3, IEEE Std 802.3-2018 |
| Application | Edge DCI |
Applications and Optical Link Design
This coherent interface is suited to data-center interconnect, metro transport and managed DWDM links where the host platform supports the stated modulation and FEC modes. Design the optical line around the actual launch power, receiver range, OSNR requirement and span loss; the stated reach is not a substitute for a link-budget calculation. Use matching coherent modules and the appropriate DWDM channel plan at both ends.
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.
Coherent deployment requires a line-system review, not merely a matching connector. Confirm the DWDM channel, launch-power range, receiver limits, OSNR and FEC mode at both ends. Span loss and amplifier operation must remain inside the supported envelope, and stated reach should be validated against the actual route.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -13~-9dBm. 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.
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 400Gbps, wavelength 1528.77~1566.52nm, rated reach Amplified: ≤120km Unamplified：≤40km.
HPE Aruba Compatibility and Factory Testing
The module is checked for host recognition as S4B38A, 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.
Ordering Information
Quote HT part number QDD-ZR-400G together with OEM reference S4B38A and quantity. Add the host model and software release when pre-order verification is required. Neutral labels, customer packaging and project-specific compatibility review are available on request.
Quality Assurance and Packaging
Before packing, the module receives interface inspection, identification and link checks. Protective packaging avoids pressure on the connector and latch. Customer references, rack groups and project packing lists can be added for volume orders.
Frequently Asked Questions
Is this an original HPE Aruba transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies S4B38A, not an original HPE Aruba-branded module.
Which fiber and connector are required?
Use Duplex LC/UPC with SMF. The specified maximum reach is Amplified: ≤120km Unamplified：≤40km, 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.