Fiber optic transceiver module Cisco GLC-SX-MMD 1000 Mbit/s SFP 850 nm

The Cisco GLC-SX-MMD is a 1000BASE-SX SFP fiber optic transceiver module for multimode fiber (MMF) operating at an 850 nm wavelength. Designed for short-range Gigabit Ethernet links, the module supports an extended operating temperature range and Digital Optical Monitoring (DOM). It features a dual LC/PC connector and a compact SFP form factor for straightforward insertion into compatible Cisco and other SFP-equipped network devices.

Advantages

The module delivers 1000 Mbit/s data transfer over multimode fiber with a standardized SFP interface, enabling hot-pluggable installation and straightforward replacement. Extended operating temperature support increases reliability in varied environments, while DOM provides real-time monitoring of optical parameters. Dual LC/PC connectors ensure secure duplex fiber connections and broad interoperability with standard MMF cabling.

Suitable for

• Short-range Gigabit Ethernet links over multimode fiber
• Switch-to-switch and switch-to-server uplinks
• Data center and enterprise access layer connections
• Environments requiring optical monitoring (DOM)

Key specifications

• Form factor: SFP (small form-factor pluggable)
• Standard: 1000BASE-SX
• Wavelength: 850 nm
• Fiber type: Multimode fiber (MMF)
• Data rate: 1000 Mbit/s
• Connector: Dual LC/PC
• Features: Extended operating temperature range, DOM support
• Manufacturer part number (MPN): GLC-SX-MMD

How to use

Insert the GLC-SX-MMD into an available SFP port on a compatible network device until it latches. Connect LC duplex multimode fiber cables to the module’s dual LC/PC connectors, observing correct transmit/receive orientation. Ensure the host device supports the module and enable DOM monitoring if required through the device management interface. Verify link status and negotiated speed via the switch or router diagnostics.

Recommendations

Use multimode fiber with appropriate cable grades (e.g., OM1–OM4) for short-range links and confirm compatibility with your network equipment firmware. Regularly monitor DOM readings to detect signal degradation and perform routine inspection of LC connectors to maintain optical performance.