25G SFP28

25G SFP28 · 15 models

25G SFP28 Transceivers for Data Centers

25G SFP28 transceivers covering 25GBASE-SR at 100 m, LR at 10 km, ER at 40 km, ZR at 80 km and single-fiber BiDi builds with DDM. Specifications and enquiry.

See the models Ask for a recommendation

Buying guide

What this family covers.

A 25G SFP28 is the pluggable optic used for 25 Gigabit Ethernet on server adapters, top-of-rack switches and 5G fronthaul equipment. It keeps the SFP mechanical form and the 3.3 V hot-pluggable interface, so port density stays the same as a 10G design, while raising the lane rate to 25 Gb/s. All modules in this category support digital diagnostics, which lets the host read optical power, temperature, voltage and bias current for each port.

The range covers the full reach ladder. Short links inside a rack or row use a 25GBASE-SR module, an 850 nm VCSEL design over multimode fibre with a duplex LC interface, specified at 100 m. Beyond that, single-mode optics take over: 25GBASE-LR at 1310 nm for 10 km, 25GBASE-ER at 1310 nm for 40 km, and a ZR class module at 1310 nm using an EML transmitter with a semiconductor optical amplifier to reach 80 km. Single-fiber BiDi models are also listed, at 20 km on a 1270 and 1330 nm pairing and at 80 km on a 1295 and 1309 nm pairing, both with a simplex LC interface.

The practical decision sequence is fibre type first, then measured loss, then strand count. After that, confirm the coding the host platform expects and whether forward error correction has to be enabled for the chosen variant.

  • SR for in-rack multimode, LR upward for anything single-mode
  • Check whether the platform requires FEC on the chosen variant
  • BiDi models save a strand and ship as matched pairs
  • OM4 gives more margin than OM3 on 25G multimode links

Models

15 listed 25G SFP28 products.

Filter the family, then open a model for the full specification table, illustrations and ordering information.

Category

Data rate

Form factor

Media

Listed reach

116 of 116 products

Selection

Choosing within this family.

25G SFP28 variants in this range and the link each one suits.

VariantWavelengthTypical reachFiber / mediaWhere it fits
25GBASE-SR850 nm VCSEL100 mOM4 multimode, duplex LCServer to top-of-rack, in-row switching
25GBASE-LR1310 nm10 kmG.652.D single-mode, duplex LCBuilding to building, spine uplinks
25GBASE-ER1310 nm40 kmG.652.D single-mode, duplex LCMetro links and data centre interconnect
25G ZR1310 nm, EML with SOA80 kmG.652.D single-mode, duplex LC5G fronthaul and long metro spans
25G BiDi BX201270 / 1330 nm20 kmSingle-mode single strand, simplex LCFronthaul and access on one fibre
25G BiDi BX801295 / 1309 nm80 kmSingle-mode single strand, simplex LCLong single-fiber metro routes

Listed values describe the published range. Confirm the exact model datasheet, host coding and installed link before ordering.

Before you order

What to confirm.

Forward error correction changes the reach

At 25 Gb/s the link budget assumed by a standard often includes forward error correction, and whether FEC is on is a property of the switch port and its configuration rather than of the optic. A pair of modules that works on one platform can show errors on another simply because FEC is disabled at one end. Check what the host requires for the variant you are fitting, make sure both ends match, and treat a link that comes up but accumulates errors as a configuration question before assuming a hardware fault.

Multimode grade matters at 25G

A 25GBASE-SR module is specified at 100 m, and reaching that figure depends on the multimode fibre installed. OM4 carries the full distance with margin, OM3 gives noticeably less, and older OM1 or OM2 plant is not suitable for 25G at any useful length. Check the fibre records before assuming a short data hall link will work. Where the cabling is older, either re-terminate onto OM4 or move the link to single-mode optics rather than trying to stretch the multimode plant.

Choosing between ER, ZR and BiDi for long links

Beyond 10 km there is more than one way to make the link. An ER module reaches 40 km on two strands, a ZR class module with an optical amplifier reaches 80 km, and a BiDi pair reaches 80 km on a single strand. The right answer usually depends on what the fibre costs rather than on the optics. Where strands are leased individually, the BiDi option can be the cheaper build even though the modules themselves carry a premium. Get the measured loss before deciding.

Breakout, port speed and coding

Many 25G links terminate on ports that can also run at 10G, or on a 100G port broken out into four 25G lanes with a splitter cable. Both cases depend on the host platform supporting the configuration and on the port being set for the intended speed. Confirm the port mode as well as the module, and confirm the coding the platform expects from the EEPROM. Where the estate mixes vendors, the same optical variant may be needed under more than one code.

FAQ

25G SFP28 questions.

What is the difference between 25GBASE-SR and 25GBASE-LR?

SR is an 850 nm design that runs over multimode fibre and is specified at 100 m, which suits links inside a rack or row. LR is a 1310 nm design that runs over single-mode fibre and is specified at 10 km, which suits links between buildings or between halls. Both use a duplex LC connector, so the deciding factor is the fibre already installed and the distance.

Can a 25G SFP28 module run at 10G?

Some platforms allow a 25G port to operate at 10G, but that is a property of the switch port rather than of the optic, and a 25G optic is not automatically a dual rate part. Where a port has to support both rates, confirm it in the switch documentation and confirm the module is specified for the lower rate as well. Otherwise use a 10G SFP+ module in a port configured for 10G.

How far can 25G run over multimode fibre?

The SR modules here are specified at 100 m, which assumes OM4 multimode fibre. OM3 gives a shorter usable distance, and older OM1 and OM2 plant is not suitable for 25G links of any practical length. If the installed fibre is unknown, check the cable jacket markings or the cabling records before ordering, because the fibre grade rather than the optic sets the limit.

Do 25G SFP28 links need FEC?

It depends on the variant and the platform. Forward error correction is part of the link budget assumed by several 25G modes, and whether it is enabled is decided by the switch port configuration at both ends. A mismatch shows up as a link that comes up but reports errors. Check what the switch requires for the variant being installed and make sure both ends are configured the same way.

Related families

Also worth comparing.

10G SFP+17 models100G QSFP2817 models40G QSFP+15 models

Next step

Not sure which 25G SFP28 model fits?

Send the host platform, the fibre you have and the distance you need. We will shortlist the models that actually work and quote them.

Ask for a shortlist