Cisco GLC-LH-SM-20 Compatible 1G SFP Transceiver Module

Product Highlights

• Compatible alternative to Cisco GLC-LH-SM-20
• 1G connectivity at 1.25Gbps
• Optical wavelength: 1310nm
• Specified reach: 20km
• Duplex LC/UPC / SMF interface
• Digital diagnostic monitoring: Supported
• Operating temperature: 0 to 70°C (32 to 158°F)

Specifications

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.

Before deployment, check the host port type, supported data rate and firmware requirements. The 1G interface configuration must match the remote equipment; sharing a SFP housing alone does not make two transceiver types interoperable.

The single-mode link budget should include fiber attenuation, connectors, splices and panels over the intended 20km route. Keep the Duplex LC/UPC interface clean and match the remote optical standard. Consider receiver overload as well as insufficient power on short links.

Quality Assurance and Packaging

Each GLC-LH-SM-20 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.

Optical Acceptance, Diagnostics and Handling

For this model, the specified transmit-power range is -9.5~-3dBm; the stated optical power budget is 13.5dB. 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.

Data-Center Optical Design and Airflow

Select the module by optical standard, reach and rack layout. Check the complete fiber channel, including panels and connectors, and keep dense bundles from blocking front-panel airflow. Account for listed power consumption and preserve enough space to remove a module without disturbing adjacent links. For this model, the principal parameters are data rate 1.25Gbps, wavelength 1310nm, rated reach 20km.

Ordering Information

When ordering, specify GLC-LH-SM-20, SFP1G-ELX-31, 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.

Cisco Compatibility and Factory Testing

Compatibility testing for GLC-LH-SM-20 combines identification with a live link and available transmit, receive and alarm information. Connector condition is inspected separately. Equipment model, hardware revision and software release can be reviewed before dispatch where platform behavior is uncertain.

Frequently Asked Questions

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.