Cisco GLC-LH-SMD Gigabit SFP transceiver module, MMF/SMF Multimode & SingleMode

Cisco GLC-LH-SMD is a high-performance, hot-swappable SFP (Small Form-factor Pluggable) transceiver module designed for Gigabit Ethernet deployments. It supports the IEEE 802.3z 1000BASE-LX/LH standard and is compatible with both single-mode fibre (SMF) and multimode fibre (MMF) links—making it flexible for data centres, enterprise wiring closets and campus networks. With a 1310 nm wavelength, LC duplex connector, digital optical monitoring (DOM) capability and support for link spans up to 10 km on SMF and ~550 m on MMF, this module offers a cost-effective way to extend or upgrade network fibre connectivity while maintaining robust compatibility with Cisco switches and routers.

Product Features

Hot-Swappable SFP Form Factor

The GLC-LH-SMD can be inserted or removed without powering down the host device, resulting in minimal network disruption and simplified serviceability.

Support for Both Single-Mode and Multimode Fibre

Rated for up to 10 km on standard single-mode fibre and up to ~550 m on legacy multimode fibre (with mode-conditioning patch cable when required), this module provides flexibility for mixed fibre-media environments.

1310 nm Wavelength, LC Duplex Connector, Digital Optical Monitoring

Utilising a 1310 nm laser transmitter and LC duplex interface, the GLC-LH-SMD offers excellent optical performance, and supports DOM/diagnostics for monitoring real-time operating parameters (temperature, optical output, received power).

Broad Compatibility with Cisco Platforms

Designed for use with a wide range of Cisco switches and routers that include SFP ports, this module helps standardise gigabit optics across the network infrastructure, reducing inventory complexity.

Product Specifications

• Module type: SFP (Small Form-factor Pluggable)
• Standard: IEEE 802.3z 1000BASE-LX/LH
• Wavelength: 1310 nm nominal
• Connector: LC duplex female (optical)
• Media types supported: Single-mode fibre (9/125 µm) up to ~10 km; Multimode fibre (50/125 µm or 62.5/125 µm) up to ~550 m (depending on fibre type and condition)
• Digital Optical Monitoring (DOM): Supported (for extended versions)
• Operating temperature: Standard commercial (0 °C to ~70 °C) and extended/industrial variants available (-5 °C to 85 °C or -40 °C to 85 °C) depending on SKU.

Deployment Tips

• Verify the fibre type and link span: Single-mode fibre for long runs (up to ~10 km), multimode fibre for shorter runs (≤ 500-600 m).
• Use mode-conditioning patch cables when deploying on legacy multimode fibre with single-mode optics to avoid modal dispersion issues.
• Ensure the host device SFP port supports the GLC-LH-SMD or equivalent optics—some platforms may require a specific optics whitelist or firmware support.
• Monitor the module via DOM for optical power levels and link health, helping early detection of cable degradation or connectors needing cleaning.