Cisco GLC-LH-SMD Compatible 1G SFP Transceiver Module
The GLC-LH-SMD compatible module serves equipment requiring a 1G SFP interface with 1310nm optics and a 10km on SMF rating. Connection is through Duplex LC. Product data, application guidance and factory verification are presented together to support procurement teams match an equipment parts list to a clearly defined optical product.
OEM Part Number: GLC-LH-SMDHT Part Number: SFP1G-LX-31
Product Highlights
- Compatible alternative to Cisco GLC-LH-SMD
- 1G connectivity at 1.25Gbps
- Optical wavelength: 1310nm
- Specified reach: 10km on SMF
- Duplex LC / SMF interface
- Operating temperature: -40 to 85°C (-40 to 185°F)
- Factory compatibility verification and optical performance testing before shipment
Specifications
| Cisco Compatible | GLC-LH-SMD |
|---|---|
| Manufacturer | HT |
| HT Part Number | SFP1G-LX-31 |
| Form Factor | SFP |
| Max. Data Rate | 1.25Gbps |
| Wavelength | 1310nm |
| Max. Cable Distance | 10km@SMF |
| Connector | Duplex LC |
| Optical Components | FP 1310nm |
| Media | SMF |
| DOM Support | Yes |
| TX Power | -9.5~-3dBm |
| Receiver Sensitivity | < -23dBm |
| 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.
The single-mode link budget should include fiber attenuation, connectors, splices and panels over the intended 10km on SMF route. Keep the Duplex LC 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; receiver sensitivity is < -23dBm. 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.
Procurement and Asset Identification
A useful purchase order identifies the host platform, expected OEM code and optical standard separately. This prevents a module with the same housing but another wavelength, reach or identification profile from being substituted. For mixed deployments, keep one order line per OEM reference and reconcile each received unit with its intended port. For this model, the principal parameters are data rate 1.25Gbps, wavelength 1310nm, rated reach 10km on SMF.
Cisco Compatibility and Factory Testing
Compatibility testing for GLC-LH-SMD 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
Use GLC-LH-SMD as the compatibility cross-reference and SFP1G-LX-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.
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
Is this an original Cisco transceiver?
No. It is an HT-manufactured compatible alternative for equipment that specifies GLC-LH-SMD, not an original Cisco-branded module.
Which fiber and connector are required?
Use Duplex LC with SMF. The specified maximum reach is 10km on SMF, 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.