HPE Aruba 845398-B21 Compatible 25G SFP28 SR Transceiver Module

This HPE Aruba 845398-B21 compatible transceiver provides 25G connectivity in a hot-swappable SFP28 package. Its optical design operates at 850nm for up to 100m on OM4 / 70m on OM3, using Duplex LC. Complete parameters and related OEM references help structured fiber installations preserve a documented and serviceable optical channel.
OEM Part Number: 845398-B21HT Part Number: SFP-25GSR-85
Product Highlights
- Compatible alternative to HPE Aruba 845398-B21
- 25G connectivity at 25.78Gbps
- Optical wavelength: 850nm
- Specified reach: 100m on OM4 / 70m on OM3
- Duplex LC / MMF interface
- Digital diagnostic monitoring: Supported
- Operating temperature: 0 to 70°C (32 to 158°F)
Specifications
| HPE Aruba | 845398-B21 |
|---|---|
| Manufacturer | HT |
| HT Part Number | SFP-25GSR-85 |
| Form Factor | SFP28 |
| Max Data Rate | 25.78Gbps |
| Wavelength | 850nm |
| Max Cable Distance | 100m@OM4/70m@OM3 |
| Connector | Duplex LC |
| Media | MMF |
| Transmitter Type | VCSEL |
| Receiver Type | PIN |
| TX Power | -8.4~2.4dBm |
| Minimum Receiver Power | <-5.6dBm |
| Power Budget | 2.8dB |
| Receiver Overload | 2.4dBm |
| Power Consumption | ≤1W |
| Extinction Ratio | >2dB |
| CDR (Clock and Data Recovery) | TX & RX Built-in CDR |
| Inbuilt FEC | Yes |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Protocols | SFF-8472, SFF-8024, SFF-8431, SFF-8432 |
| DDM/DOM | Supported |
| Core Size | 50/125 µm |
| Packaging Technology | COB Packaging |
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 Duplex LC 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 25G interface configuration must match the remote equipment; sharing a SFP28 housing alone does not make two transceiver types interoperable.
For this multimode module, confirm fiber grade, modal bandwidth and total loss before commissioning. The 100m on OM4 / 70m on OM3 figure applies only under suitable cabling conditions. Inspect every Duplex LC mating point and match the remote optical standard.
HPE Aruba Compatibility and Factory Testing
Factory verification starts with the expected 845398-B21 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.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -8.4~2.4dBm; the stated optical power budget is 2.8dB. 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.
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 25.78Gbps, wavelength 850nm, rated reach 100m on OM4 / 70m on OM3.
Ordering Information
Quote HT part number SFP-25GSR-85 together with OEM reference 845398-B21 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.
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
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 845398-B21, not an original HPE Aruba-branded module.
Which fiber and connector are required?
Use Duplex LC with MMF. The specified maximum reach is 100m on OM4 / 70m on OM3, 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.
845398-B21