StarTech SFP-25G-SR-S-C-ST 25Gbps SFP28 Multimode Fiber Transceiver (Cisco-Compatible)

Overview

The StarTech SFP-25G-SR-S-C-ST is a 25Gbps SFP28 multimode fiber transceiver engineered as a drop-in compatible replacement for the Cisco SFP-25G-SR-S. It operates over OM4 or OM3 multimode fiber at 850nm with LC duplex connectors, delivering up to 100 meters of reach — enough for most intra-building backbone and top-of-rack to distribution switch runs. If you're scaling spine-leaf or high-density server interconnects and need a cost-effective way to populate SFP28 ports without sourcing OEM optics at OEM prices, this is the practical answer.

Drawing under 1.2W, the SFP-25G-SR-S-C-ST won't stress your switch's thermal or power budget even when you're populating a full 48-port chassis. The module complies with IEEE 802.3cc 25GBASE-SR standards, so link negotiation and optical parameters are by-the-book — no firmware workarounds required on supported Cisco platforms.

Key Features

• 25Gbps Data Rate via SFP28 Form Factor: Four times the bandwidth of 10GbE SFP+ in the same port footprint. If you're running 25G NIC uplinks from servers or storage nodes, this transceiver matches the line rate end-to-end without creating a bottleneck at the fiber link.
• 100m Reach on Multimode Fiber: Covers the vast majority of intra-building horizontal and vertical cable runs. If your IDF-to-MDF distance is under 100m on OM3 or OM4 cable — which describes most enterprise wiring closet architectures — you don't need a more expensive single-mode solution.
• 850nm Wavelength, LC Duplex Connector: The industry-standard wavelength for short-reach multimode links. LC duplex is universally supported in patch panels and fiber cassettes, so you won't need to re-terminate or source specialty connectors for an install.
• IEEE 802.3cc 25GBASE-SR Compliance: Adherence to this standard means the optical output power, receiver sensitivity, and extinction ratio are within spec for proper link margin. Non-standard optics are a common root cause of intermittent CRC errors and link flaps — standards compliance here matters more than it sounds.
• Sub-1.2W Power Consumption: At under 1.2W per module, heat dissipation stays low even in fully populated high-port-count switches. Compare this to active DAC or AOC alternatives that can run warmer in dense chassis — relevant when you're managing inlet temperature budgets in a packed rack.
• 0°C to 70°C Operating Temperature: Rated for standard data center and wiring closet environments. The storage temperature range extends to -40°C to 85°C, so transit and warehouse staging in cold climates won't damage the module before installation.
• Cisco SFP-25G-SR-S Compatible: Coded to identify correctly on supported Cisco platforms, bypassing the incompatible transceiver error that blocks link-up on uncoded third-party optics. Confirm platform compatibility against your specific Cisco switch model and IOS/NX-OS version before deploying at scale.
• Lifetime Warranty: StarTech backs this transceiver with a lifetime warranty — meaningful for infrastructure components that are typically installed and forgotten for years. If the module fails, you're covered without a support contract negotiation.

Integration and Compatibility

The SFP-25G-SR-S-C-ST (often searched as SFP 25G SR S C ST) is designed for Cisco switches and line cards that accept the SFP-25G-SR-S OEM part. It uses the SFP28 form factor, which is backward-compatible with SFP+ slots at reduced data rates on platforms that support auto-negotiation — though for 25G operation, the host port must be a native SFP28 slot. Pair this transceiver with a quality network switch that supports 25G SFP28 interfaces for clean link-up. For structured cabling guidance in high-density deployments, review a network infrastructure planning guide to validate fiber type and cable length budgets before ordering. This module is suited to data center switching fabrics, enterprise campus backbones, and high-bandwidth NVR and storage network uplinks where 10G has become a throughput constraint. Browse the full StarTech networking line for compatible fiber patch cables, DACs, and switch accessories. For PoE switches and uplink planning in security and AV deployments, the PoE switch category covers complementary infrastructure.

Frequently Asked Questions

Q: Is the SFP-25G-SR-S-C-ST compatible with Cisco Nexus and Catalyst switches?

A: It is designed as a coded compatible replacement for the Cisco SFP-25G-SR-S and is intended to work on Cisco platforms that accept that OEM part number. Always verify compatibility against your specific switch model and software version before deploying across a production environment.

Q: What fiber type does the SFP-25G-SR-S-C-ST require?

A: It operates over multimode fiber (MMF) at 850nm with LC duplex connectors. OM4 fiber supports the full 100m rated distance; OM3 may support shorter runs. Single-mode fiber is not compatible with this module.

Q: What is the maximum cable distance for the SFP-25G-SR-S-C-ST?

A: The rated maximum transfer distance is 100 meters over multimode fiber. This covers most intra-building runs but is not suitable for inter-building or campus-scale distances that require single-mode optics.

Q: What warranty comes with the SFP-25G-SR-S-C-ST?

A: StarTech provides a lifetime warranty on the SFP-25G-SR-S-C-ST. This applies to the transceiver itself and covers manufacturing defects over the product's usable life.

Q: How much power does the SFP-25G-SR-S-C-ST draw?

A: Power consumption is rated at under 1.2W. This is low enough that even a fully populated 48-port SFP28 chassis will not face unusual thermal or power budget pressure from the transceivers alone.

Q: Can the SFP-25G-SR-S-C-ST be used in non-Cisco equipment?

A: The module is specifically coded for Cisco compatibility. Use in non-Cisco equipment is not confirmed by the available evidence — verify with your specific platform vendor before purchasing for non-Cisco deployments.

Marty Allison

The SFP-25G-SR-S-C-ST is the module I reach for when an integrator needs to populate Cisco SFP28 ports without paying OEM pricing for every port in the chassis. The sub-1.2W power draw is the spec that catches most people off guard — at scale, that thermal efficiency makes a real difference in dense deployments where switch inlet temps are already being watched.

Technical Highlights:

• 25Gbps over 100m MMF: Hits the full rated line rate of a 25G SFP28 port over existing OM3/OM4 plant — no infrastructure changes needed if your fiber is already multimode.
• IEEE 802.3cc Compliance: Standards-compliant optical parameters mean proper link margin and no mystery CRC errors that plague out-of-spec third-party optics. Link stability is determined by physics, not vendor negotiation.
• Lifetime Warranty: For a transceiver installed in a wiring closet that won't be touched for a decade, a lifetime warranty removes the long-tail support risk entirely — no contract renewals, no per-incident fees.

Deployment Considerations:

• The module is coded specifically for Cisco platforms — validate the exact switch model and IOS/NX-OS version supports third-party SFP28 optics before committing to a large quantity order. Some Cisco platforms require a config knob to permit non-OEM transceivers.
• Operating temperature ceiling is 70°C — standard for commercial data center environments, but not rated for extended-range industrial or outdoor wiring enclosures that can exceed this threshold in summer months.

This transceiver is the right call for enterprise IT or physical security teams building out 25G spine-leaf fabrics or high-bandwidth NVR uplinks on Cisco switching infrastructure, where controlling per-port optic cost matters at 24- or 48-port scale.