Juniper Networks SFP-GE40KM Compatible 1.25G SFP Transceiver Module

This Juniper Networks SFP-GE40KM compatible transceiver provides 1.25G connectivity in a hot-swappable SFP package. Its optical design operates at 1310nm for up to 40km, using Duplex LC. Complete parameters and related OEM references help high-density deployments balance optical performance, port access and thermal planning.
OEM Part Number: SFP-GE40KMHT Part Number: SFP1G-EX-31
Product Highlights
- Compatible alternative to Juniper Networks SFP-GE40KM
- 1.25G connectivity at 1.25Gbps
- Optical wavelength: 1310nm
- Specified reach: 40km
- Duplex LC / SMF interface
- Operating temperature: -40 to 85°C (-40 to 185°F)
- Factory compatibility verification and optical performance testing before shipment
Specifications
| Juniper Networks Compatible | SFP-GE40KM |
|---|---|
| Manufacturer | HT |
| HT Part Number | SFP1G-EX-31 |
| Form Factor | SFP |
| Max. Data Rate | 1.25Gbps |
| Wavelength | 1310nm |
| Max. Cable Distance | 40km |
| Connector | Duplex LC |
| Optical Components | DFB 1310nm |
| Media | SMF |
| DOM Support | Yes |
| TX Power | -5~0dBm |
| Receiver Sensitivity | < -24dBm |
| Industrial Temperature Range | -40 to 85°C (-40 to 185°F) |
| Protocols | SFF-8472 MSA Compliant, IEEE 802.3ah-2004 |
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.
The industrial temperature rating makes this version appropriate for controlled outdoor cabinets, transport nodes and other installations exposed to wider ambient temperature variation. Adequate airflow, protected cable routing and host-platform temperature limits still apply.
Before commissioning, measure the complete single-mode channel against the stated budget for 40km. Inspect every Duplex LC connection and record diagnostic power where supported. Both ends must agree on rate, wavelength and optical standard.
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.
Optical Acceptance, Diagnostics and Handling
For this model, the specified transmit-power range is -5~0dBm; receiver sensitivity is < -24dBm. 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. 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.
High-Density Port and Thermal Planning
In a densely populated chassis, connector access and airflow form part of the optical-link design. Confirm that neighboring modules and patch leads leave room for latch operation, and include listed power consumption in the host thermal budget. Assess port density together with fiber management. For this model, the principal parameters are data rate 1.25Gbps, wavelength 1310nm, rated reach 40km.
Ordering Information
Use SFP-GE40KM as the compatibility cross-reference and SFP1G-EX-31 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.
Juniper Networks Compatibility and Factory Testing
Factory verification starts with the expected SFP-GE40KM 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.
Frequently Asked Questions
Is this an original Juniper Networks transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies SFP-GE40KM, not an original Juniper Networks-branded module.
Which fiber and connector are required?
Use Duplex LC with SMF. The specified maximum reach is 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.
10/100BASE-T SFP