StarTech SFP-25G-LR-S-M-ST MSA-Compliant 25Gbps SFP28 Single-Mode Fiber Transceiver

Overview

The StarTech SFP-25G-LR-S-M-ST is a 25Gbps SFP28 optical transceiver built to the MSA (Multi-Source Agreement) standard, designed for enterprise and data center network links where you need to push full 25GbE throughput across single-mode fiber (SMF) at distances up to 10 km (6.2 mi). At under 1.2 W power draw, it fits cleanly into high-density switch deployments without straining per-port power budgets. If you are expanding a spine-leaf fabric, interconnecting buildings across a campus, or extending storage or video infrastructure over existing SMF plant, this module covers the distance without requiring a media converter or dedicated fiber link hardware.

MSA compliance means the SFP-25G-LR-S-M-ST is engineered to interoperate with SFP28 slots across a broad range of switches and network interface cards — without being locked to a single vendor's ecosystem. That matters in mixed-vendor environments where forcing proprietary optics either introduces cost premiums or requires switch-specific firmware workarounds.

Key Features

• 25Gbps Data Rate: Full 25GbE throughput on a single fiber pair — the right move when 10GbE links are becoming your bottleneck but 100GbE is more capacity (and cost) than the segment justifies. Commonly used for server-to-switch uplinks and inter-switch connections in modern collapsed-core designs.
• 10 km (6.2 mi) Reach over SMF: The 1310nm wavelength over single-mode fiber gets you across a large campus or between buildings without repeaters or amplifiers. Multimode fiber won't work here — this module is SMF-only, which is worth confirming against your existing fiber plant before ordering.
• LC Duplex Connector: LC duplex is the standard interface for SFP28 SMF links. If your patch panels are already LC-terminated, no adapter hardware is needed — just plug in and configure.
• MSA-Compliant Design: Compatibility is enforced at the hardware and electrical level by adhering to the SFP28 MSA specification. This significantly reduces the risk of vendor lock-in compared to OEM-coded optics. Always verify your switch vendor's compatibility list or test in a lab environment before deploying at scale.
• Sub-1.2 W Power Consumption: In a 48-port chassis fully populated with 25G modules, aggregate optical power draw adds up fast. At under 1.2 W per port, this module keeps per-slot thermal and power budgets manageable — particularly relevant in high-density ToR (top-of-rack) switch deployments.
• Operating Temperature 0°C to 70°C (32°F to 158°F): Covers standard data center and IDF/MDF closet environments. This is a commercial-temperature-range module — if you are deploying into an industrial enclosure or outdoor hardened switch with elevated ambient temps, confirm your environment stays within this range.
• Storage Temperature -40°C to 85°C (-40°F to 185°F): Wide storage range means modules can be warehoused or shipped in non-climate-controlled conditions without risk of spec degradation before deployment.
• 85% RH Humidity Tolerance: Handles the humidity levels typical of server rooms and wiring closets without requiring additional environmental controls beyond standard HVAC.
• Lifetime Warranty: StarTech backs this module with a lifetime warranty — meaningful for a passive optical component that, once installed and stable, should remain in service for the life of the switch it is seated in. Reduces long-term replacement cost risk on infrastructure-layer links.

Integration and Compatibility

The SFP-25G-LR-S-M-ST (often searched as SFP 25G LR S M ST) seats into any SFP28 form-factor slot. SFP28 slots are backward-compatible with SFP+ modules in most implementations, but 25G throughput requires a native SFP28 port on both ends of the link. Verify that the far-end switch or NIC also supports 25GbE — a 10GbE SFP+ port at the remote end will negotiate down to 10G or may not link at all depending on auto-negotiation behavior. Both ends of the fiber run must use compatible 25G LR optics operating at 1310nm on OS2 single-mode fiber. Mixing wavelengths or fiber types across a link will result in no connectivity. For campus inter-building runs, confirm existing OSP (outside plant) fiber is OS1 or OS2 single-mode — this module will not operate over OM3/OM4 multimode.

Frequently Asked Questions

Q: What fiber type does the SFP-25G-LR-S-M-ST require?

A: This module requires single-mode fiber (SMF), specifically OS1 or OS2 grade, with LC duplex connectors at both ends. It will not function over multimode fiber (OM1, OM2, OM3, or OM4). The operating wavelength is 1310nm.

Q: What is the maximum reach of the SFP-25G-LR-S-M-ST?

A: The rated maximum transfer distance is 10 km (6.2 miles) over single-mode fiber at 25Gbps.

Q: Will the SFP-25G-LR-S-M-ST work in a switch that requires vendor-coded optics?

A: MSA compliance means this module is designed to interoperate with SFP28 ports across vendors, but some switches (notably certain Cisco, Juniper, and Arista platforms) enforce vendor coding and may generate warnings or refuse to enable uncoded optics without CLI overrides. Verify your switch vendor's policy and test before deploying at scale.

Q: What is the warranty on the SFP-25G-LR-S-M-ST?

A: StarTech provides a lifetime warranty on this module.

Q: Can this module be used for 10GbE links?

A: This module is rated for 25Gbps and is designed for 25GbE (SFP28) applications. While SFP28 ports are often backward-compatible with SFP+ at 10G speeds, this specific module is not specified or warranted for 10GbE operation — use a dedicated SFP+ LR module if 10GbE is your target data rate.

Q: What are the operating temperature limits for the SFP-25G-LR-S-M-ST?

A: The operating temperature range is 0°C to 70°C (32°F to 158°F). This is a commercial-grade temperature range suitable for standard data center and wiring closet environments, but not rated for extended industrial temperature ranges.

Jerry Tildsen

The SFP-25G-LR-S-M-ST is the module I reach for when a project involves inter-building SMF runs in the 1–10 km range and the design calls for 25GbE — typically server uplinks in a spine-leaf fabric or high-bandwidth video distribution backbones where 10GbE is running out of headroom. The 1310nm wavelength over OS2 single-mode is a proven combination for this distance, and the sub-1.2 W power draw means you can fully populate a 48-port switch without hitting thermal or power budget ceilings.

Technical Highlights:

• 25Gbps / 10 km SMF: The rated 10 km reach over single-mode at 25Gbps covers virtually every enterprise campus inter-building scenario without requiring optical amplification or intermediate repeaters.
• Under 1.2 W per port: In a fully loaded 48-port 25G switch, that is under 58 W total for optics alone — manageable within standard switch power supply headroom and within most rack PDU budgets.
• Lifetime warranty: Infrastructure-layer optics rarely fail once they are stable, but when they do, replacement logistics matter. The lifetime coverage removes the need to track module warranty expiry on individual ports across a large deployment.

Deployment Considerations:

• Confirm your fiber plant is OS1 or OS2 single-mode before ordering — this module produces no link on multimode fiber, and misidentified legacy fiber runs are a common field issue on campus upgrades.
• The 0°C to 70°C operating range is commercial grade only. If this module is going into a hardened outdoor switch or an enclosure in a non-climate-controlled space, verify ambient temperatures stay within range — industrial-temp variants are required for environments that exceed 70°C.

This module is a practical fit for enterprise campus backbone links and data center server-to-ToR uplinks where existing OS2 SMF infrastructure is already in place and 25GbE is the target throughput tier — particularly in video surveillance aggregation architectures pushing high-channel-count streams to central recording infrastructure over long campus runs.