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.

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.

Mixed-Vendor Network Operation

A mixed-vendor optical link should be documented at both ends, not treated as one generic connection. Confirm which OEM identity each host expects and whether both ends use the same wavelength plan and optical standard. Related links locate equivalent hardware, but brand-specific identification must still be selected independently. For this model, the principal parameters are data rate 1.25Gbps, wavelength 1310nm, rated reach 20km.

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.

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.

Quality Assurance and Packaging

Quality control covers the optical or electrical interface, host identification and operating link. The verified unit is then individually protected and cartoned. Customer references, rack groups and project packing lists can be added for volume orders.

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.