GLC-LH-SMD 1G SFP LX Single-Mode Transceiver (1310nm)

Brand: Cisco | Category: Transceivers & Cables

SKU: GLC-LH-SMD | Part #: GLC-LH-SMD | MPN: GLC-LH-SMD

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The GLC-LH-SMD operates at 1310 nm wavelength over single-mode fiber (OS1/OS2, 9/125 µm) with a maximum reach of 10 km—a specification that shapes how network architects plan their metropolitan area networks and campus backbone deployments across enterprise and data-centre facilities. This Cisco transceiver brings the extended distance capability of 1000BASE-LX to organisations that need to span multiple buildings or connect geographically separated data centres without introducing regeneration points. The 1310 nm wavelength chosen for this module represents the sweet spot in the optical spectrum: it offers lower attenuation over long distances than shorter wavelengths, making it the natural choice for anyone moving Gigabit traffic across standard single-mode fibre cable plants already installed in most large facilities.

Network engineers typically select the GLC-LH-SMD when they're upgrading or expanding backbone infrastructure where the fibre run exceeds what multimode optics can reliably deliver. Where a standard 1000BASE-SX transceiver maxes out at 220–550 metres depending on fibre grade, the LX variant opens the possibility of spanning 10 kilometres of dark fibre—a critical difference when connecting a production data centre to a disaster recovery site, or when provisioning inter-building links in a sprawling enterprise campus. The transceiver itself is a hot-swappable SFP module no larger than a USB stick, yet it carries the intelligence to monitor its own performance in real time. Cisco engineered the GLC-LH-SMD with digital optical monitoring (DOM) built in, which means administrators gain live visibility into transmit power, receive signal levels, and module temperature without requiring external test equipment. That real-time diagnostic window matters in operational environments where network uptime is measured in nines and troubleshooting must happen quickly.

The optical performance of the GLC-LH-SMD sits well within Cisco's standards. Transmit power ranges from −3 dBm to −9.5 dBm, and the receiver sensitivity reaches −20 dBm maximum—specifications that guarantee reliable operation across the full 10 km reach over OS1 or OS2 single-mode fibre, or over multimode fibre at shorter distances when paired with a mode-conditioning patch cable for 550 metre runs. The transceiver uses 8B/10B encoding, the same line code standard that underpins the 1000BASE-LX IEEE 802.3z specification, ensuring seamless interoperability with any compliant switch port or line card. Power consumption remains modest at 3.3 V supply voltage, a design choice that lets the GLC-LH-SMD coexist peacefully with other modules in a densely populated SFP cage without straining power delivery infrastructure. The laser operates at Class 1 safety level, meeting regulatory requirements in all markets without special handling restrictions.

Compatibility is straightforward: the Cisco GLC-LH-SMD plugs into any SFP-equipped port on Catalyst switches, Nexus data-centre platforms, ISR routers, or ASR aggregation gear. This ubiquity across Cisco's product line—from edge to core—makes the module a reliable workhorse for network teams maintaining heterogeneous infrastructure. Storage architects and AI infrastructure teams who are provisioning direct-attached storage or high-speed interconnects between compute nodes in different racks or buildings will often specify this transceiver as the fibre interface of choice. The LC duplex connector is standard across the industry, so patching into existing fibre infrastructure presents no surprises. Whether a customer is lighting up a new fibre run or swapping out end-of-life optics in a live production environment, the hot-swappable design means no downtime—pull the old module, insert the new one, and the link comes up within seconds, assuming the far-end transceiver is already in place.

The GLC-LH-SMD occupies a middle ground in Cisco's transceiver portfolio: it costs more than multimode LX variants that max out at 300 metres, but it delivers real 10 km reach without the expense of coherent optics or pluggable modules with active cooling. For organisations replacing worn-out 1000BASE-LX transceivers or upgrading from legacy equipment, this part number delivers exactly the capability needed without overspending on features that metropolitan-area links don't require. The 1310 nm wavelength choice also allows coexistence with other wavelengths on the same fibre strand if DWDM multiplexing becomes a future requirement, giving the infrastructure some room to grow. Cisco's longstanding reputation for manufacturing quality means the GLC-LH-SMD carries the expectation of multi-year reliable service—a consideration that factors heavily into total cost of ownership calculations in data centres and enterprises where unexpected module failures ripple through operational SLAs.

Performance and Optical Specifications

• Operating wavelength 1310 nm with 10 km maximum reach over OS1/OS2 single-mode fibre (9/125 µm)
• Transmit power −3 dBm to −9.5 dBm and receive sensitivity to −20 dBm for reliable long-distance links
• Digital optical monitoring (DOM) provides real-time visibility into transmit power, receive levels, and module temperature
• 8B/10B encoding and full 1000BASE-LX/LH (IEEE 802.3z) compliance ensure interoperability with standards-based infrastructure
• Hot-swappable SFP form factor with LC duplex connectors integrates into existing fibre cable plants without infrastructure changes
• Secondary support for multimode fibre (with mode-conditioning patch cable) extends reach to 550 metres for short-haul deployments
• Class 1 laser safety rating permits operation in standard data-centre and enterprise environments without special precautions
• 3.3 V supply voltage and compact footprint minimise power and space overhead in multi-module SFP cages

Omnixon Global stocks the Cisco GLC-LH-SMD and related optical transceiver modules for enterprises, data-centre operators, and service providers across the Gulf Cooperation Council, Asia-Pacific, and Europe. Our technical team understands the fibre cable plant constraints and distance requirements that drive transceiver selection in real deployments—we're here to help you specify the right optics the first time. If you're planning a backbone upgrade, replacing end-of-life modules, or building out a new metropolitan-area link, contact our sales and technical teams to discuss your requirements and request a quotation.