SFP transceiver module HP 1.25Gbps 1000BASE-LX SM 20km 1310nm LC duplex with DMI (J4859D)

HP SFP transceiver module 1.25Gbps 1000BASE-LX is a small form-factor pluggable optical module designed for gigabit Ethernet over single-mode fiber. The module transmits at 1310 nm and supports link lengths up to 20 km using an LC duplex connector. It operates from a 3.3 V supply, supports 1.25 Gbps data rate and includes digital optical monitoring (DMI) for real-time diagnostics. The module is intended for installation in compatible SFP ports on switches, routers and optical uplink equipment in data centers and enterprise networks.

Advantages

This HP SFP transceiver provides a compact, hot-pluggable solution for establishing long-reach gigabit links over single-mode fiber. Built-in digital optical monitoring allows network administrators to view parameters such as transmit and receive power, temperature and laser bias for easier diagnostics and maintenance. The LC duplex interface and industry-standard SFP form factor ensure broad compatibility with equipment that accepts 1000BASE-LX modules.

Suitable for

• Fiber uplinks between switches and routers within campus and enterprise networks
• Long-reach connections to edge devices or aggregation points up to 20 km
• Fiber-based server or storage connectivity in data centers requiring single-mode links
• Replacement or expansion of existing 1000BASE-LX SFP ports

Key specifications

• Data rate: 1.25 Gbps (Gigabit Ethernet)
• Optical standard: 1000BASE-LX
• Wavelength: 1310 nm
• Maximum link length: up to 20 km over single-mode fiber
• Connector: LC duplex
• Form factor: SFP (small form-factor pluggable)
• Power supply: 3.3 V
• Operating temperature range: 0 to 70 °C
• Diagnostic feature: Digital optical monitoring (DMI)

How to use

Ensure the host device supports 1000BASE-LX SFP modules and that the SFP slot is powered down or follows hot-plug procedures described by the equipment vendor. Insert the transceiver into the SFP port until it latches, then connect single-mode LC duplex fiber patch cords with correct polarity. After insertion, verify link status on the host device and use the DMI registers to check optical power, temperature and other diagnostic parameters via the management interface. Observe vendor guidelines for hot-plugging and static-sensitive handling.

Usage recommendations

For reliable operation, use single-mode fiber with appropriate attenuation budget for distances up to 20 km, keep LC connectors clean and use dust caps when modules are unused. Monitor DMI values periodically to detect degradation in optical power or temperature anomalies, and follow the equipment vendor's compatibility list to ensure full interoperability.